 Box 4.12  Midazolam Dosage:  LV route: Above 12 years, 5 mg slowly—patient may  need encouragement to breathe after [V midazolam.  IM route: Adult: 0.2 mg/kg, Not to exceed 10 mg in  total.  Child: 0.1—0.2 mg/kg, not to exceed 10 mg in total  Nasal Spray: Child: 0.2 mg/kg body weight (Max:  5 mg/nares)  Rectal: Adult and children above 12 years: 10-20 mg,  can be repeated once after 10-15 min if needed  Child 2-11 years: 5-10 mg, can be repeated  once after 10-15 min    Box 4.14  Midazolam is a benzodiazepine that carries the risk of  respiratory depression. Patients need close monitoring  after drug administration and may need respiratory  support.   Typical grand mal seizure, in a known epileptic patient,  where the seizure has subsided within a couple of min-  utes, patient can be discharged with the carer, provided  all the vital signs are with in normal range. Urgent hos-  pital transfer is indicated in all other epileptic  seizures.    Energy demands of the brain are met primarily by oxidation  of glucose. A regular and constant supply of glucose and  oxygen is essential for brain function. Supply of both glu-  cose and oxygen depends on effective perfusion of the brain.  When brain perfusion decreases beyond a critical level, the  patient loses consciousness and the balance gets affected and  the patient falls.   ¢ Seizure, if the patient is not positioned in a horizontal  position quickly.   ¢ Let fresh air by opening a window or a fan   ¢ Once recovered, encourage the patient to have a sugary  drink.    Although syncope is the most common cause of loss of con-  sciousness, the other causes should also be borne in mind, as  some of them can be quite serious, such as:    ¢ Loss of consciousness following a sudden change of pos-  ture from supine or sitting to standing upright.   e Place them in a supine position and bring them to the  upright position slowly.    Excessive breathing in an anxiety state or excessive crying  resulting in drop of blood CO, level.   e Tingling or numbness in the arms and in the perioral  region   e Use a paper bag to rebreath exhaled air to build up CO  levels    Preparedness for emergency is the key and when you are pre-  pared, emergencies are easier to manage. The maxillofacial  surgeon should be able to recognize these conditions and ini-  tiate appropriate management before professional emer-  gency help is available. More often, maxillofacial surgeon is  the lone clinician and is the sole responder in an emergency.  It is prudent for the surgeon to know what to do and what not  to do to get the best out of the worst scenario or situation.   It is imperative that the maxillofacial surgeons thoroughly  understand the pathophysiology and extend their skills to  recognize and manage expeditiously and effectively the  emergencies that may arise. It is advisable that the contem-  porary clinicians update their knowledge and skills periodi-  cally with proper training courses.   Protocols given here are based on the currently avail-  able evidence, keeping in view of the local healthcare sys-  tems and access. As protocols are only suggestive, the  clinician is strongly advised to use his or her own discre-  tion when dealing with medical emergencies (Table 4.1;  Flowchart 4.1).    Table 4.1 Causes of loss of consciousness and its age distribution    Flowchart 4.1 Management algorithm for a collapsed patient where  the cause of collapse is not known    1. Thim T, Krarup NHY, et al. Initial asseement and treatment with  the Airway, Breathing, Circulation, Disability, Exposure (ABCDE)  approach. Int J Gen Med. 2012;5:117-21.   2. Saglani S, Fleming L, Sonnappa S, et al. Advances in the aetiology,  management, and prevention of acute asthmatic attack in children.  Lancet Child Adolesc Health. 2019;3(5):354-64.   3. Fergeson JE, Patel SS, Lockey RF. Acute asthma, prognosis, and  treatment. J Allergy Clin Immunol. 2017;139(2):438-47.   4, Marsh B, Drake MG. Outpatient management of acute exacerbations  of obstructive lung diseases. Med Clin N Am. 2017;101(3):537-5S1.   5. Hahner S. Acute adrenal crisis and mortality in adrenal insuffi-  ciency. Ann Endocrinol. 2018;79(3):164-6.   6. Paur THK, Stikkelbroeck NMMI, et al. Adrenal crisis: still a deadly  event in the 21st century. Am J Med. 2016;129(3):339.   7. Schwartz A. Airway mangement for the oral surgery patient. Oral  Maxillofac Surg Clin N Am. 2018;30(2):207—26.   8. Chapman J, Lalkhen AG. Anaphylaxis. Anaesth Intensive Care  Med. 2017;18(1):16—21.   10. Moore LE, Kemp AM, Kemp SF. Recognition, treatment,  and prevention of Anaphylaxis. Immunol Allergy Clin N Am.  2015;35(2):363-74.   11. Waller JR, Waller DG. Drugs for systemic hypertension and angina.  Medicine. 2018;46(9):566-72.   12. Dym H, Barzani G, et al. Emergency drugs for the dental office.  Dent Clin N Am. 2016;60(2):287-94.    Herman WW, Ferguson HW. Dental care for patients with heart  failure: an update. J Am Dent Assoc. 2010;141(7):845-53.   Yates EJ, Schmidbauer S, et al. Out of hospital cardiac arrest termi-  nation of resuscitation with ongoing CPR: an observational study.  Resuscitation. 2018;130:21-7.   Fernando SM, Vaillancourt C, et al. Analysis of bystander CPR  quality out of hospital cardiac arrest using data derived from  AED. Resuscitation. 2018;18:138-43.   Pollack RA, Brown SP, et al. Bystander automated external defi-  brillator application in non-shockable out of patient cardiac arrest.  Resuscitation. 2019;137:168-74.   Bansal N, Dhaliwal R, et al. Management of diabetes in elderly.  Med Clin N Am. 2015;99(2):35 1-77.   RD, Surges R, et  2019;393(10172):689-701.  Paris M, Reddy U. Update on the management of status epilepticus.  Anaesth Intensive Care Med. 2018;19(3):83-6.   Papavasiliou AS, Kotsalis C, et al. Intravenous midazolam in con-  vulsive status epilepticus in children with pharmacoresistant epi-  lepsy. Epilepsy Behav. 2009; 14(4):661—-4.   Numeroso F, Mossini G, et al. Emergency department management  of patients with syncope according to the 2018 ESC guidelines. Int  J Cardiol. 2019;283:119-21.    Open Access This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.  org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropri-  ate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.   The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in  a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.   Pain, the dreaded symptom, is an unpleasant sensation that  draws the attention of the individual as a whole. Its manage-  ment has greatly evolved in the field of dentistry, starting  from the leaves of a coca tree to articaine, Comfort Control  Syringe (CCS) system, Transcutaneous Electrical Nerve  Stimulation (TENS), Computer-Controlled Local Anesthetic  Delivery System as well as oral and intravenous sedatives.  Apart from all these, local anesthesia (LA) is the favored  mode of pain control in the profession. The painless surgery  under LA is must; otherwise, endogenous catecholamines  are released if there is excessive pain during dental treat-  ment, which can alter the hemodynamic status such as an  increase in blood pressure and heart rate and even dysrhyth-  mias [1].   The first local anesthetic isolated from the leaves of a coca tree  in 1860 by Neiman was cocaine, and it was Karl Koller in  1884 who showed the anesthetic effect of Cocaine. In 1905,  Einhorn popularized Procaine as an effective local anesthetic.  It was derived from benzoic acid and diethyl amino ethanol. In  1948, the anesthetic property of lignocaine was discovered by  Lofgren, and T. Gordh applied it in dental surgery [2].    Local anesthesia is defined as a reversible loss of sensation in  the circumscribed area of the body caused by depression of    © The Association of Oral and Maxillofacial Surgeons of India 2021    excitation in the nerve endings or inhibition of the conduc-  tion process in peripheral nerves [2].   e It should not cause structural changes to nerve and  have low systemic toxicity.   e Its onset of action should be short and should be  stable in solution.   e It should be effective as both injectable and topical  application.   e Its action should be long enough to allow the proce-  dure to be completed.    Table 5.1 Classification of local anesthetic agents: based on chemical  structure    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1-15-1346-6_5    Table 5.2 Classification of local anesthetic agents: based on duration  of action   Pulpal anesthesia: less than 10 min  Soft-tissue anesthesia: 30-45 min  Short acting   The LA agents have been divided into Esters and Amides  groups. The commonly used Amides are Lidocaine,  Articaine, and Bupivacain [2].    5.3.1 Lidocaine (Lignocaine)  Lofgren in 1943 introduced the prototype amide local anes-  thetic [2], i.e., Lidocaine.   The other similar names are xylocaine, octocaine, den-  tocaine. Chemically, it is Diethyl 2, 6 dimethy] acetanilide.  The maximum recommended dosage for Lignocaine with  vasoconstrictor is 7 mg/kg not exceeding 500 mg and  without vasoconstrictor is 4.4 mg/kg not exceeding  300 mg. Its onset of action is 2-3 min and duration of  action with vasoconstrictor is 45-75 min, without vaso-  constrictor is less than 30 min. Its contraindications  include Ehlers Danlos syndrome and Attention-deficit  hyperactive syndrome. Lignocaine is available in the form  of jelly, spray, patches, and ointments. The toxicity arises  from inadvertent intravascular administration or from  overdose.   Recently, Howlader et al. [3] suggested open reduction  and internal fixation (ORIF) of isolated subcondylar frac-  tures under local anesthesia by using 2% lidocaine with  1:200,000 epinephrine for mandibular nerve block and supe-  rior cervical plexus blocks (SCPB).   To anesthetize the cutaneous branches of SCP (lesser  occipital, greater auricular, transverse cervical, and supracla-  vicular nerve), the solution is deposited at the midpoint of  the posterior border of sternocleidomastoid muscle border,  as well as inferior and superior to that point subcutaneously  creating a field block.   The anesthetic agent selection should be based on three  main clinical considerations: anesthetic potency and latency,  onset, and duration. The composition of the local anesthetic  solution is shown in Table 5.3.    from being trapped in cartridge and potentially  destroying vasopressor or vasoconstrictor.   It is four times more potent than prilocaine, lidocaine, and  mepivacaine. It is less toxic than lidocaine and mepivacaine  and it is metabolized in the liver by amidases and excretion  via kidney 16% unchanged. Its onset of action is similar to  lidocaine, mepivacaine, and prilocaine. Effective dental con-  centration is 0.5% and anesthetic half-life is 2.5 h.   Maximum recommended dose is 1.3 mg/kg body wt to a  maximum of 90 mg. Because of its long duration of action, it  is advisable for use in lengthy surgical procedure and the  management of postoperative pain. Hence, the patient’s  requirement for postoperative opioid analgesics is lessened  when bupivacaine is used. Bupivacaine is not recommended  in young patients as the risk of self-mutilation is increased.   The duration of soft-tissue anesthesia has been consis-  tently shown to be longer than with lidocaine [4] and thereby  reducing postoperative pain experience [5].   The potency of Articaine is 1.5 times more than ligno-  caine and 1.9 times than procaine. Its onset of action when  used with vasoconstrictor is 1-2 min. Half-life is approxi-  mately 21 min and it is metabolized to pharmacologically  inactive metabolite called articaine acid glucoronide. Since it  is rapidly biotransformed to its inactive metabolite, it is a  safe local anesthetic agent. It is excreted via kidney    unchanged (5—10%) and as metabolite (90%). The maximum  recommended dosage for articaine is 0.8 mg/kg body weight.   Contraindications for the use of articaine are Idiopathic  or congenital methemoglobinuria, hemoglobinopathies,  hypoxia, and in patients with cardio-respiratory failures.  Prolonged paraesthesia has been reported as a complication  following inferior alveolar nerve block (IANB) [6].   Articaine with epinephrine is the best choice to improve  anesthesia in both inflamed and in uninflamed tissues with  good results, and more effective anesthesia for longer dura-  tion can be achieved [7]. Table 5.4 shows maximum recom-  mended dose of commonly used LA.    1. To decrease the tissue perfusion and therefore to decrease the  blood flow at the site of drug administration, which further  decreases the absorption of local anesthetics into the circula-  tory system. Therefore, the blood levels of the anesthetic  agents remain low, thereby decreasing the risk of toxicity [2].   2. It also increases the time taken by the local anesthetic to  be absorbed from the site of administration and therefore  increases the duration of action of the local anesthetic.    Most commonly used vasoconstrictors are epinephrine,  norepinephrine, levonordefrin hydrochloride, phenylephrine  hydrochloride.   The explanation of 1:1000 vasoconstrictor concentration is  that 1 g/1000 mg of solute is present in 1000 ml of the solu-  tion, which means | mg of solute in 1 ml of solution. In the  local anesthetic solution, the concentration of vasoconstric-  tor is less. The concentrations used are 1:80,000 or 1:100,000  or 1:200,000. The concentration of 1:100,000 of the vaso-  constrictor would contain 1000 mg in 100,000 ml of the  solution. Therefore, | ml of 1:100,000 concentration would  contain 0.01 mg in | ml.    Concentration  milliliter(mg/ milliliter (g/ cartridge (1.8  (dilution) ml) ml) ml)  1:1000 1.0 1000   1:20,000 0.05 50 90  1:30,000 0.033 Sih3) 13  1:50,000 0.02 20 36  1:80,000 0.0125 3) TES)  1:100,000 0.01 10 18  1:200,000 0.05 5 9    The absorption of vasoconstrictors is dose dependent and  may last from minutes to half an hour. The patients with cardio-  vascular compromise are at increased risk with endogenously  released epinephrine in response to stress rather than the epi-  nephrine, which is injected with the local anesthetic (Table 5.5).    5.6 LA Toxicity and Antidote for Toxicity  Symptoms, which reflect toxicity from the administration of  local anesthetic solution, may range from mild cutaneous  reactions to severe life-threatening anaphylactic reactions.  There are a variety of methods and drugs to treat these reac-  tions symptomatically. However, the reversal of toxicity,  including damage to vital organs such as the heart and brain, is  still less understood. A clinically efficient antidote for a com-  plete reversal of toxicity is still beyond our grasp currently.   Intravenous lipid emulsion (IVLE) is being reported as a res-  cue measure for LA toxicity. This has been studied and  proven in both animal models and in limited human trials  with successful resuscitation outcomes. The lipid emulsion  acts on the plasma and tissue and extracts the lipophilic anes-  thetic molecules, thereby reversing their inhibitory myocar-  dial effects. Bolus doses of 1.2—2 ml/kg followed by  continuous infusion of 0.25-0.5 ml/kg/min are currently  advocated for adequate efficacy. This drug needs to be used    judiciously as optimal dosages have not been established and  the risks of overdosage are not clearly understood.   The duration of soft-tissue anesthesia often exceeds that of  pulpal or bony anesthesia. This is an important reason for the  occurrence of undesirable events like accidental lip or tongue  biting, difficulties in speaking, eating, or drinking liquids,  etc. Various drugs have been studied to decrease the postop-  erative duration of anesthesia. Of the various drugs tried  clinically, phentolamine is one drug, which has demonstrated  appreciable clinical efficacy.   Phentolamine is a nonselective alpha-adrenergic antago-  nist that is reversible. Its main action is vasodilatation. It has  been used effectively for controlling hypertensive emergen-  cies, especially in pheochromocytomas. In dental practice,  Phentolamine in the form of phentolamine mesylate injec-  tions has been used as a reversal agent against LA by revers-  ing the action of vasoconstrictors in the LA solution and  expedites the metabolism of the LA molecules. The recom-  mended dose for phentolamine is the administration of  1.8 ml of the solution containing 0.4 mg of phentolamine  mesylate immediately after treatment.    It is preferred for patients having comorbidities such as cir-  culatory disorder to avoid complications and adverse sys-  temic effects of vasoconstrictors [8]. Lip laceration is one of  the common cases, which are attended to by a maxillofacial  surgeon in the emergency department for suturing. Localized  blanching caused by the use of local anesthetic with adren-  alin at the lacerated wound causes difficulty in locating the  exact demarcation between skin, white roll, and lip.  Therefore, LA without epinephrine is preferred in such cases  before suturing [9].   The solution used for this purpose is 5% Lignocaine, 10%  Lignocaine, combination of 2.5% lignocaine and 2.5% prilo-  caine [10]. They are indicated in patients [11, 12]    The form of drug used to obtain this includes ointment, gel,  viscous, cream, spray, etc. Topical application of these forms  can produce anesthesia on the surface, particularly of the oral  mucosa.   This is used often, before an actual injection for L.A, at the  site of injection, in order to reduce the pain of the needle prick  itself. It can also be used to obtund pain in situations where  the oral mucosa is breached, as in an ulcer in the oral mucosa.  The gel may also be used to anesthetize the surface mucosa,  e.g., nasal, pharyngeal, etc., before a diagnostic endoscopy.   The concentration of a local anesthetic applied topically  is typically greater than the same drug administered by injec-  tion. Drugs that are commonly employed in topical L.A for-  mulations are Benzocaine and Lidocaine.   EMLA, which is a eutectic mixture of local anesthetic  agents, lignocaine, & prilocaine in the ratio 1:1 by weight,  has been found to be a very useful topical agent to be applied  on the skin, before painful procedures like injection, veni-  puncture, etc. and is used extensively in children. This par-  ticular cream, which is oil-in-water emulsion, may also be  used for surface anesthesia of the oral mucosa for purposes  listed earlier.    In local infiltration, deposition of the local anesthetic solu-  tion in the area of the surgery to anesthetize small terminal  nerve endings. Field block involves the deposition of anes-  thetic solution near the large terminal nerve branches to pre-  vent the passage of impulses from teeth to the central nervous  system. In nerve block, local anesthesia is deposited away  from the site of surgery, but close to the main nerve trunk.   Different techniques for mandibular nerve block anesthe-  sia have been published, including the mental/incisive nerve  block [13-15].    1. The standard (Halsted) technique  2. The standard indirect technique  3. Mental nerve (incisive nerve) block  — standard approach for mandibular anteriors and soft  tissue  — anterior approach  — extraoral approach  4. Clarke-Holmes technique (1959)   9. Gow-Gates technique (1973)  10. Ipsilateral open-mouth technique (2007)  11. Morishita (positive aspiration) technique (2007)  12. Extraoral submandibular approach  13. Lateral extraoral approach  14. Anterior extraoral approach. (1969)    1. Anterior-superior alveolar nerve and infraorbital nerve  blocks,  — intraoral approach (bicuspid approach)  — Bisecting approach (central incisor)  — extraoral approach  — nasal approach (1969)  2. Posterior-superior alveolar nerve block (tuberosity block)  3. Middle-superior alveolar block (buccal  approach)  4. Middle and anterior-superior alveolar nerve block (pala-  tal approach)  5. Sphenopalatine (incisive) nerve block  . Greater palatine nerve and lesser palatine nerves block  7. Maxillary nerve blocks,  — High tuberosity approach  — Greater palatine canal approach  — nasal approach  — lateral extraoral approach  — suprazygomatic extraoral approach extraoral approach  — anterior-lateral extraoral approach.    During IANB, the intravenous injection of local anesthetic is  very common. Frangiskos F et al. [16], in their study, found  positive aspiration (the tip of the needle is in the blood ves-  sel) 20% times. The positive aspiration was more commonly  seen in young patient’s age ranging from 9 to 19 years. To  avoid systemic complications while giving local anesthesia,  aspiration is must in each and every case.    5.11.2 Controversy in the Use of Bilateral IANB  and Lingual Nerve Block [17]    Has bilateral IAN and Lingual nerve block been given?  Some surgeons recommend, while some do not, but there are  no published data available regarding its contraindications.  The common complications associated with its use are   — Loss of control of tongue, which can lead to respiratory  embarrassment    Many authors advocated the use of sodium bicarbonate in  addition to the lignocaine solution to reduce the duration of  onset of anesthesia, and it is very effective in reducing pain  during the injection. Sodium bicarbonate ions also nonspe-  cifically reduce the safety margin for nerve conduction and it  has a direct action on the binding of Local anesthetic to the  sodium channel [19-21].    5.12.1 Inferior Alveolar Nerve Block (Also  Known as Mandibular Nerve Block)  [Along with Lingual & Long Buccal  Nerve Blocks]    This is the single most important nerve block, whose tech-  nique needs to be mastered. With this, we can anesthetize the  whole of the mandibular soft and hard tissues, including the  cheek, and many procedures in this region can be carried out.  Secondly unlike in the maxilla, infiltration techniques do not  provide adequate anesthesia to the hard tissue in the mandible,  particularly the teeth. This is due to the dense cortical bone in  the mandible, in contrast to the porous maxillary bone, where a  paraperiosteal deposition of the solution can allow the solution  to diffuse through the bone to the periapical region easily and  cause anesthesia of the teeth and their supporting structures.    This description is for injection on the right side of the  patient and for a right-handed operator. The surgeon is on the  right side of the patient, in front of the patient. The patient is  asked to open the mouth wide.   With the left hand, the operator palpates the posterior buccal  sulcus, runs the index finger posteriorly to feel the external  oblique ridge and the anterior border of the coronoid process. As  the finger proceeds upwards, palpate the coronoid process up  and down to determine the deepest point on its anterior border.  This is the coronoid notch. [This is a very important landmark  because this determines the vertical height at which the needle  should be inserted, the reason being the Mandibular foramen on  the medial aspect of the ramus where we want the needle to  reach is in direct line with the coronoid notch] Fig. 5.1.   Once the coronoid notch is palpated with the pulp of the  index finger, the finger is rotated such that the nail faces  medially. At the same time, the finger retracts the soft tissue    Fig. 5.2 Picture showing needle insertion position from the soft tissue  for IAN block    to reveal a depression called the pterygo mandibular depres-  sion, which is medial to the finger between the finger and the  pterygo Mandibular raphe (Fig. 5.2).   Now the needle with solution in the syringe is taken in the  right hand and is introduced into the mouth from the oppo-  site side (i.e., left side) corner of the mouth/premolar area.   The syringe and needle are kept parallel to the Mandibular  occlusal plane and are introduced into the pterygo temporal  depression at the same height as the nail of the index finger  (on the coronoid notch). The needle is advanced slowly in  the soft tissue till the needle strikes the bone and resistance is  felt. Now the needle is in the pterygo mandibular space  bounded laterally by the medial surface of the ramus of the  mandible and it is just above the lingula in the area of the  opening of the mandibular foramen.    The syringe is aspirated and 1 ml of the solution is deposited.  This will anesthetize the inferior alveolar nerve as it enters the  mandible. Now, the needle with the syringe is swung on to the  corner of the mouth on the same side, i.e., right, and is slowly  withdrawn after about half the length is inserted and 0.5-0.8 ml  of the solution is deposited here. This will take care of the lingual  nerve, which is anteromedial to the inferior alveolar nerve.   Now the needle is withdrawn completely out of the soft  tissue and is reinserted into the cheek, posterior to the last  molar teeth at the level of the occlusal plane of the mandibu-  lar teeth for a short distance. After aspiration, the remaining  0.5 ml of the solution is deposited. This anesthetizes the long  buccal nerve [for the left-sided block, the surgeon is slightly  behind the patient on the right side with the left hand coming  around].   This classical Mandibular Nerve block of inferior alveo-  lar nerve with lingual & long buccal is done together if the  mandibular molars and their adjoining soft tissues need to be  anaesthetized. The reason being the pulp and the periodon-  tium of these teeth are supplied by the inferior alveolar nerve.  The lingual gingiva is supplied by the lingual nerve and the  buccal gingiva by the long buccal nerve.    1. Inferior Alveolar Nerve Block  (a) All mandibular teeth and the bone surrounding them.  (b) The buccal gingiva in relation to the Mandibular  anterior and premolar teeth.  (c) Lower lip on the same half up to the midline.  2. Lingual Nerve Block  (a) The lingual gingiva of the Mandibular teeth along  with the lingual Mandibular mucosa.  (b) The Anterior 2/3rd of the tongue on the same side.  3. Long buccal nerve Block  (a) The cheek mucosa.  (b) Buccal gingiva and mandibular mucosa in relation to  the molar teeth.    It usually takes about 3-5 min before adequate depth of  anesthesia is obtained after any injection. In other words,  although symptoms of anesthesia may be felt almost instantly  after the injection, for the patient to feel no pain during the  procedure a wait of at least 5 min is needed.   It has been conventional to confirm the anesthesia  obtained with two parameters:    1. Subjective symptoms of anesthesia as experienced by the  patient.  2. Objective signs elicited by the surgeon.    Subjective symptoms may or may not be present with cer-  tain nerve blocks, e.g., nasopalatine block. However with the  classical inferior alveolar/mental nerve block, a tingling and  numbness on one half of the lip (same side) will be felt.  There will be an area of sharp demarcation between the  numb side of the lip and the normal side at the midline. The  tingling or numbness will start instantly to become heavy in  about 3-5 min. Similar sensation of numbness will be felt on  the same side of the tongue particularly the tip as a result of  the lingual nerve block. There may be no symptoms of  numbness felt by the patients in the other anaesthetized  areas, e.g., the gingiva, teeth, or the cheek.   The objective sign as elicited by the surgeon is more reliable  and may be the only means of ascertaining anesthesia in the  absence of subjective symptoms. The objective sign of anesthe-  sia is lack of pain in the area anesthetized when stimulus is  applied with a blunt instrument, e.g., the end of a periosteal  elevator. [It should be noted from the earlier discussion that the  patient might feel the pressure of the instrument and an appre-  hensive patient might occasionally interpret this as pain.]   In checking for anesthesia of the inferior alveolar nerve, the  blunt instrument must be applied on the buccal gingiva anterior  to the mental foramen, because the lack of sensation in the pos-  terior buccal soft tissue indicates a successful long buccal nerve  and not inferior alveolar nerve block. The same blunt instrument  must be applied in the gingival sulcus on the lingual side of the  tooth to be extracted for lingual nerve anesthesia. The same can  be done to check the buccal nerve anesthesia.    These were discussed very briefly as local complications of  L.A in the earlier section. Specific complications after an  Inferior Alveolar Nerve block include:   Paresthesia Adverse drug reactions  Facial nerve paralysis Overdose drug reactions  Trismus Psychogenic reactions  Soft-tissue injury   It is the most common problem and usually due to the wrong  technique. Repeating the block employing the right tech-  nique is usually the solution. However, this might be encoun-  tered in two other situations.    1. Failure to anesthetize the myolohyoid branch, which  might occasionally innervate the site of the procedure.   2. Also as already mentioned, in an apprehensive patient,  the symptoms of pressure may be interpreted as pain. In  this situation, anxiety reduction techniques may be  needed or alternately some other form of anesthesia, e.g.,  conscious sedation or General Anesthesia may have to be  employed. The subjective symptom of numbness in the  lower lip (same side) and tip of the tongue will be the  distinguishing feature between a faulty technique and an  apprehensive patient. In the former, it will be absent, and  in the latter very much present.   This may occur within the pterygo mandibular space as a  result of bleeding induced by the needle prick. It may be a  rare problem. The patient might have pain, swelling, & dif-  ficulty in opening the mouth. The treatment is symptomatic  and possibly prophylactic antibiotic cover. It will resolve  spontaneously.   May occasionally occur as a result of a faulty technique  where the needle is inserted farther posteriorly into the sub-  stance of the parotid gland (in this situation, the needle would  have failed to encounter bony resistance) and paralyzes the  facial nerve.   The patient will have typical signs of ipsilateral facial nerve  palsy/weakness, which includes difficulty in closing the eye,  absence of wrinkles on the forehead, and drooping of the cor-  ner of the mouth ipsilaterally with a possible asymmetry. This  effect will be transient, till such time the local anesthetic effect  persists (about 1-11 h) and the patient needs to be reassured.   Is a relatively more common complication and will be seen  usually postoperatively. It could be due to a variety of causes,  including:    1. Muscle spasm due to injury  2. Infection  3. Necrosis of tissue due to contact with contaminants, etc.    Most of the time it resolves spontaneously. But on occa-  sion, this will require anti-inflammatory analgesics, muscle  relaxants, and vigorous physiotherapy to overcome the prob-  lem. Wherever an infection is suspected, a suitable antibiotic  cover may also be needed.    5.12.5.5 Accidental Breakage of the Needle  Occurring within the tissues of the pterygo mandibular space,  this is a very rare complication today where we use dispos-  able needles for one use only. But when this happens, a radio-  graphic guided exploration and removal of the broken piece  may be needed. Gerbino G et al. [22] advocated use of brain  LAB vector vision neuronavigation system for the retrieval of  broken needle. This Intraoperative navigation system is very  helpful in locating the broken needle fragment.    The closed mouth VA technique to anesthetize the IAN, lingual,  and long buccal nerve simultaneously was described in 1977  [23]. VA is used only secondarily to conventional IAN block.    1. In patients with restricted mouth opening  2. In cases of failure of IAN blocks  3. Difficult-to-locate landmarks for IAN block    The percentage of Positive aspiration is much higher with  IAN block in comparison to VA. This is because of the close  proximity of the inferior alveolar artery, which enters the  mandibular foramen just behind the nerve [25]. To avoid fre-  quent aspiration, many surgeons prefer VA technique in nor-  mal patients also.    A 25-gauge long needle is used. The operator is in front of  the patient on the right side (right-handed operator) for both  sides on the patient.   With the left index finger or thumb, the coronoid notch is  palpated and the soft tissues on the medial aspect of the  ramus are pushed laterally. The needle is held parallel to the  maxillary occlusal plane on the same side of the injection  and is inserted adjacent to the maxillary third molar into the  soft tissue overlying the medial border of the ramus, just  adjacent to the maxillary tuberosity. This is now advanced  posteriorly & slightly laterally. The bevel of the needle is  away from the mandibular ramus and in an average-sized  adult the needle is inserted about 25 mm into the tissue. At  this point, the tip of the needle will be in the middle of the  pterygo mandibular space close to the branches of the man-  dibular nerve. After aspiration, the LA solution is injected.   The areas anesthetized, signs and symptoms of anesthesia are  similar to the open-mouth technique of mandibular nerve block.    Another viable alternative to the VA block is the tech-  nique of Gow-Gates described in 1973. In the Gow-Gates  technique, anesthesia is administered more proximally, at the  neck of the condyle and relies on extraoral landmark [26].    A 25-gauge long needle is used. The operator stands in front  of the patient. It is very essential for the patient to extend his  neck & open the mouth as wide as possible. Here the needle is  inserted into the mucosa medial to the mandibular ramus on a  line parallel to a line drawn from the intertragic notch to the  corner of the mouth—just distal to the maxillary second molar.  The needle is inserted from the corner of the mouth on the  opposite side. The height of insertion is just at the level of the  mesiolingual cusp of the maxillary second molar. Slowly  advance the needle till the bone is contacted. (The needle here  is in contact with the neck of the condyle. The position the  patient is asked to assume, i.e., extend neck & open mouth  wide, is to facilitate a more frontal position of the condyle  closer to the mandibular nerve trunk). The average depth of  insertion is about 25 mm. Aspirate & inject 2 ml of the solu-  tion slowly. Unlike with the classical method, injection is at  one site only in this technique. This anesthetizes the inferior  alveolar, lingual, long buccal branches of the mandibular here  with similar effect as the classical block (Fig. 5.3a, b).    These are two very similar blocks except that in a mental  block the solution is deposited around the mental nerve as it  exits the mandible at the mental foramen, whereas for an  incisive nerve block, the solution is injected into the mandi-  ble through the mental foramen. This blocks the incisive  nerve, which is the continuation of the inferior alveolar nerve  anteriorly, up to the midline.    This may be carried out with the operator standing in front of  the patient (can also be done easily with the operator stand-  ing behind).   With the left-hand thumb or index finger, palpate the muco-  buccal fold on the mandible starting in the molar region mov-  ing anteriorly when depression will be felt. This is usually in  relation to the apex of the premolar teeth where the mental  foramen is present. The needle is now directed vertically to be  inserted into this area with the bevel facing the bone. With the  mental nerve block, the solution is deposited in the soft tis-  sues, whereas for the incisive the needle is inserted into the  foramen for a short distance before injection.    Fig. 5.3 (a, b) Position of needle from medial and lateral aspect in case of closed-mouth technique    Mental Nerve Block: Buccal mucosa and gingiva in the man-  dible anterior to the premolar area, lower lip mucosa, and  skin on the same side.   Incisive Nerve Block: In addition to the aforementioned  structures, mandibular teeth anterior to the mental fora-  men, i.e., incisors, canine, and the premolars (which are  anterior to the mental foramen).    Subjective: Tingling and numbness in the lower lip on the  same side for both blocks as it is for the inferior alveolar  block.   Objective: Lack of pain on probing with a blunt instrument  over the buccal gingival/mucosa in the anterior Mandibular  region.   Complications: Hematoma formation: If there is bleeding  submucosally or subcutaneously, pressure application to  stem the flow is all that is needed, with reassurance to the  patient that it will resolve spontaneously in a short period  of days.    As already mentioned, in maxilla buccal & palatal infiltra-  tion techniques are often followed because they are effective,  particularly if the surgical area is limited, e.g., extraction of  a single tooth. However nerve blocks are useful at times, par-  ticularly when anesthesia of a larger area is sought.    The position of the operator is on the front of the patient for  both sides, on the right side, for a right-handed operator.   Palpate the maxillary mucobuccal fold after asking the patient  to open mouth partially and retracting the buccal soft tissue with  the index finger of the left hand. Insert the needle (25/27 gauge—  20-mm length) into the height of the mucobuccal fold opposite  the upper second (second) molar tooth. Advance the needle in  inward, upward, backward direction with the needle at 45° angle  to the maxillary plane for about 10-15 mm. The tip of the needle  will now be close to the entry of the posterior superior alveolar  nerve into the maxilla on its posterior surface. Inject 1—-1.5 ml of  the solution after aspiration (Fig. 5.4).    1. Buccal alveolar mucosa and gingiva in relation to the  maxillary molar teeth.   2. All the three maxillary molar teeth except the mesiobuc-  cal root of the first molar in some instances. (This may be  supplied by the middle superior alveolar nerve occasion-  ally. In this case, to anesthetize the first molar tooth com-  pletely, a buccal infiltration has to be given in addition to  the posterior superior alveolar nerve block if employed.)    Hence, this is a nerve block, which may be used if multi-  ple extractions of molar teeth have to be done in the maxilla  or any other procedure in this area.    5.15.1.2 Signs and Symptoms  Subjective: The patient usually will not feel any tingling or  numbness in this case.    Objective: Lack of pain on probing with the blunt instrument  as with any other local anesthetic injection.   Complications: Most common problem is a swiftly develop-  ing hematoma particularly if the needle goes too far dis-  tally into the area of the pterygoid venous plexus.   As in earlier instances, pressure needs to be applied in this  case, on the face above the area where the swelling is devel-  oping. The sudden swelling can be alarming but is of little  consequence once the application of pressure stops flows.    Fig. 5.4 Needle insertion position in posterior superior alveolar nerve  block    Once again, reassurance to the patient is needed. Prophylactic  antibiotics to prevent secondary infection of the hematoma  may be considered.    5.15.2.1 Technique  The operator (right handed) is on the right side of the patient  for both sides, i.e., left & right.   With the left index finger, the infraorbital rim on the face  is palpated. A notch is felt on the medial third of this region,  the finger is now slid down to feel for depression below this  notch on the anterior surface of the maxilla. This is the  position of the infraorbital foramen. With the left index fin-  ger over the infraorbital foramen, the cheek is retracted  with the thumb and a 25-gauge needle is inserted intra-  orally into the height of the mucobuccal fold opposite the  first premolar with the bevel of the needle directed toward  the bone and the needle being parallel to the long axis of  the tooth. The needle is advanced until gentle bone contact  is made, and this will be the upper rim of the infraorbital  foramen.   Aspirate and inject about 1—-1.5 ml of the solution. As the  solution is deposited, firm pressure is applied over the infra-  orbital foramen by the left-hand index finger so as to facili-  tate entry of the solution into the infraorbital canal through  the foramen (Fig. 5.5a, b).    Fig. 5.5 (a, b) Position of needle insertion and target point in dry skull in Infraorbital nerve block    1. The lower eyelid, lateral side of the nose, and the upper  lip on the same side (This is due to blockade of the termi-  nal branches of the infraorbital nerve after it exits the  foramen and will happen irrespective of whether the solu-  tion has entered into the foramen)   2. The buccal gingiva & mucosa, as well as the upper ante-  rior and premolar teeth on the same side as well as the  mesiobuccal root of the first molar if it is supplied by the  middle superior alveolar nerve. (For this to happen, the  anesthetic solution injected should diffuse into the infra-  orbital canal in the floor of the orbit from where the  branches, anterior, & middle superior alveolar nerve are  given off.)   Subjective: Tingling & numbness in the areas supplied by the  terminal branches of the infraorbital nerve, i.e., the lower  eyelid, lateral side of the nose, and the upper lip on the  same side. (This symptom does not necessarily mean that  the anterior & middle superior alveolar nerves have been  anesthetized. This can be confirmed only objectively.)   Objective: Like always, lack of pain on probing with a blunt  instrument in the area anesthetized.    Injection into the palatal tissues, whether an infiltration or a  nerve block, is the most painful. The reason is the palatal  mucoperiostem is tightly adherent to the bone and there is no  easy space for the solution to flow. This also makes the pro-  cess of injection difficult as often there is backflow due to the  resistance offered.   Most often, particularly when a single tooth is involved,  infiltration anesthesia is preferred in the palate. However,  two nerve blocks are often used particularly when a larger  area is involved  1. Greater palatine nerve block  2. Nasopalatine or Anterior Palatine Nerve block.   Technique: The greater palatine foramen in the adult is usu-  ally present on the palatal side of the second molar tooth at  the junction of the alveolus and the horizontal palatine bone.  (This may be palpated as a depression in this area but need  not be done for the purpose of the nerve block.)   A 25/27-gauge short needle is inserted from the opposite  side with the operator standing in front (for both sides of the  patient) into the area palatal to the second molar at the junc-  tion of the alveolus & the palatine bone (Fig. 5.6a, b). A little  solution is deposited (0.1-0.2 ml) at the point of entry and    Fig. 5.6 (a, b) Intraoral and in dry skull showing insertion of needle in greater palatine nerve block    the needle is advanced into the foramen for a variable dis-  tance (0.5—0.7 cm) and the rest, about 0.8 ml is deposited. As  usual, always aspirate before depositing any solution.   Areas Anesthetized: The palatal gingiva of the maxillary  teeth till the second premolar on the same side as well as the  palatal mucosa & bone on the same side till the premolar  region.   Subjective: May not always be there. However, numbness in  the posterior hard palate mucosa may be present.   Objective: Confirmation of anesthesia is always by lack of  pain in the area and tested by probing with a blunt  instrument.   Technique: Operator in front with the patient mouth wide  open, a 25/27 gauge needle is inserted into the palate just  lateral to the incisive papilla. A small amount 0.1—0.2 ml of  the solution is injected after aspiration. Now the needle is  advanced further into the incisive foramen for a distance of  about 0.5—0.75 cm and 1 ml of the solution is deposited as  always after aspiration.   Areas Anesthetized: Probably the only nerve block, which  anesthetizes bilaterally symmetrical areas and hence there is  no separate right- & left-sided blocks. The palatal gingiva of  the anterior teeth up to the first premolar on either side as  well as the palatal mucosa and bone in the same anterior  region.   Objective: lack of pain in the anesthetized area on blunt  probing.   The various nerve blocks discussed so far are the com-  monly used techniques. Usually this set of techniques is suf-  ficient for all requirements of local anesthesia in the oral  cavity. There are a number of alternative techniques, intra-  oral and extraoral, which are described in literature and may  be popular in some parts of the world. However, a couple of  them will be discussed here because they may have a specific  indication or may be a popular technique.    Regional blocks are fast becoming popular in providing not  only local anesthetic support for performing surgical proce-  dures of the head and neck, but also as a method for periop-  erative pain control in the form of pre-emptive anesthetic  techniques.    This section focuses on a few regional blocks, which can  be added to the armamentarium of today’s maxillofacial  surgeon.   These may be divided into intraoral and extraoral methods [27].  The intraoral techniques include:    1. The “Greater Palatine Canal” Approach where a  25-gauge needle is passed and manipulated through the  greater palatine canal to reach the maxillary nerve trunk  at the pterygopalatine fissure (PTM fissure) and   2. The “High Tuberosity” Block Technique where the  maxillary nerve is anesthetized as it traverses the  pterygomaxillary fissure. The technique involves the  insertion of a 1.5-in. 25-gauge needle through the depth  of the mucobuccal fold lateral to the maxillary tuberosity  in a fashion similar to the posterior superior alveolar  nerve block. The depth of penetration is about 30 mm and  the target area is the pterygomaxillary (ptm) fissure pos-  terolateral to the maxillary tuberosity.   It involves a subzygomatic, technique. The clinical land-  marks include the area below the zygomatic arch anterior to  the articular eminence. This corresponds to the region above  the midpoint of the sigmoid notch of the mandible. A 25-gauge  90-mm-long spinal needle is preferred for this method; the  needle is inserted to a depth of about 45 mm till it contacts the  lateral side of the lateral pterygoid plate. The needle is then  withdrawn half-way and then angulated 15° in the forward and  upward directions, which lead it to the region of the superior  aspect of the ptm fissure, which corresponds to the exit of the  maxillary nerve from the foramen rotundum across the ptm  fissure. After negative aspiration, a volume of 2 ml is injected  into the space, and the needle is withdrawn (Fig. 5.7).    The extraoral technique for the mandibular nerve block is  very similar to the maxillary nerve block [30].  Technique—The surface landmarks and point of pene-  tration for the block are the same and so is the armamen-  tarium. The needle after penetrating the skin is advanced to    contact the lateral pterygoid plate as described earlier, fol-  lowing which the needle is withdrawn half way and turned  posteriorly by 15° to the same depth of 45 mm. This area  corresponds to the region just caudal to the foramen ovale  through which the mandibular nerve trunk exits the skull  base. After negative aspiration, a volume of 2.5—3 ml is  injected to anesthetize the mandibular nerve.   The extraoral mandibular nerve block with suprazygomatic  access can be safely and efficiently used with this unique  approach for the mandibular nerve block to get relief in pain  and Trismus. After local infiltration, an 18-gauge insulated and  stimulating cannula is inserted into the retrozygomatic space  just above the zygomatic arch and directed to the angle of  mandible with medial and posterior inclination (Fig. 5.8) [31].    This nerve block is performed as an extraoral technique and  provides good surface anesthesia to the periauricular skin  and skin over the angle of the mandible [32].  Technique—The landmarks used for this technique  include the cricoid cartilage and the posterior border of the  sternocleidomastoid muscle. With the patient supine or  semisupine, a line is drawn from the cricoid cartilage to    Fig. 5.8 Showing position of needle insertion in extraoral mandibular  nerve block    intersect the posterior border of the sternomastoid muscle.  This corresponds to the area where the superficial branches  of the cervical plexus emerge from under the sternomastoid  muscle, wrapping around the posterior border. A small sub-  cutaneous injection of local anesthetic solution (around  2 ml) will anesthetize the greater auricular nerve and its area  of distribution (Fig. 5.9).   3. Management of pain due to glossopharyngeal neuralgias  and atypical facial pain secondary to Eagle’s syndrome  [33-35]. The block can be administered both via an intra-  oral and an extraoral method. The intraoral technique is a  relatively easy and simple technique to administer pro-  ducing good outcomes.   Technique—A 25-gauge, | inch needle is chosen. The  landmark for penetration is the base of the anterior tonsillar    pillar lateral to the base of the tongue. The syringe is posi-  tioned with the barrel near the maxillary premolar of the con-  tralateral side with the needle facing the base of the anterior  tonsillar pillar. The tongue is retracted medially to provide  good visualization of the involved site. The needle is then  made to pierce the mucosa and advance by 5 mm. This cor-  responds to the target site for the glossopharyngeal nerve in  the submucosal space. After judicious aspiration, if found  negative, a volume of 3 ml of anesthetic solution (2% ligno-  caine) is administered to block the nerve trunk (Fig. 5.10).   3. Palliative pain control for patients with maxillary malig-  nancies and   4. Pre-Emptive nerve blockade for perioperative pain control  in surgical procedures of the maxilla and palate [36, 37]    Technique—There are numerous techniques for the  administration of sphenopalatine block, but the most com-  monly followed methods are the greater palatine approach  and the transmucosal approach in the posterior aspect of the  middle meatus. The greater palatine approach is the same as  the maxillary nerve block via the greater palatine canal,  which simultaneously blocks the sphenopalatine ganglion as  well. The transmucosal method, which is most commonly  followed, maybe done blind or using endoscopic guidance. A  cotton pledget on a long application stick is dipped in anes-  thetic solution or gel and is advanced transnasally to the pos-  terior aspect of the middle turbinate to reach the end of the  middle meatus. This corresponds to the level of the spheno-  palatine ganglion, which is a very superficial structure. The  local anesthetic gel is then deposited, which produces anes-  thesia through transmucosal perfusion. Another recent tech-  nique involves the submucosal injection of the anesthetic  solution into the posterior aspect of the middle meatus for  achieving the block (Fig. 5.11) [37].    Research is ongoing to find newer modalities of pain man-  agement. In order to administer local anesthesia with less  pain and adverse effects, newer technologies have been  developed. Some of them are:    This device is based on the Gate Control theory, which pro-  poses that pain during injection can be decreased by simulta-  neous stimulation of nerve fibers by vibration.   An attachment, which is battery operated, is snapped on to  the barrel to deliver strong vibrations, which is felt by the  patient and therefore reducing the perception of pain.    5.17.1.2 Dental Vibe [39]  It is a handheld device, which delivers pulsed percussive  oscillations to the site of injection, thereby closing the pain    gate. It does not have a cord and it can be recharged. Dental  vibe significantly lowered the self-reported pain during  local anesthesia injections compared to a conventional  approach.   It is a cordless device, which shuts the pain gate by precon-  ditioning the site of injection by pressure and vibration. To  energize the dental tissue in and around the site to be punc-  tured by the needle, Accupal incorporates the “Pain Gate  theory” [40].    With this device, there is a controlled delivery of the anes-  thetic and hence reduction of pain during injection. With this  device, we can slowly administer anesthesia and control the  injection speed [41].   Higher success rates for single tooth anesthesia. The absence  of pain especially in pediatric patient with disruptive behav-  ior. More effective than a traditional syringe.    Disadvantage—Difficulty in locating the precise site for  needle placement.  C-CLAD technology led to the development of an instrument  for medical and dental injections capable of controlling all  variables of subcutaneous injection event.    Allows instantaneous real-time measurement of fluid exit  pressure at the tip of the needle. This approach to fluid exit  pressure at the tip of the needle is called dynamic pressure-  sensing technology (DPS) technology.    More predictable, reliable, comfortable anesthesia than high-  pressure mechanical syringe. The system incorporates the  safety of using dynamic pressure-sensing technology allow-  ing low-pressure administration of local anesthetic drugs. All  patients receiving PDL with STA device reported subjective  pain responses of minimal or no pain.    The principle of Jet injection is that the mechanical energy is  used to force a thin column of the local anesthetic solution  through a small opening into the soft tissue under pressure  without causing tissue damage. There is less or no pain dur-  ing this procedure [42].    Local anesthetic solution in extremely small amount is  administered under pressure through an orifice seven times  smaller than the smallest available.    The protective sheath over the needle prevents accidental  needle stick injury.   The plunger, which is autoclavable and reusable, has a sterile  disposable protective shield. It does not have to be disas-  sembled prior to disposal.   Transparent disposable syringe with retractable needle  sheath is helpful in aspiration and helps in seeing the aspi-  rated contents in the syringe barrel.   Disposable syringe and needle, which is translucent with a  retractable needle into the barrel. Hence, less chance of nee-  dle stick injury. The main disadvantage is that the needle can-  not be re-exposed to readminister the remaining solution.   It is similar to the standard conventional syringe, the differ-  ence being that when the plunger reaches the bottom after all  the medicine has been administered, further push on the  plunger will cause breakage of the needle, which retracts  into the plunger. It can be used only once.   This device can be used with the armamentarium that is  available in the clinic to administer the anesthetic solution.  The main disadvantage is that inaccessible areas cannot be  anesthetized with this equipment.    X-Tip  It is a single-step method. An initial drill is placed, which allows  entry and withdrawal in one step during administration.    Pain is always a deterrent to seek treatment and hence local  anesthesia is a boon to all clinicians and patients alike.  Although the medication provides pain relief, its administra-  tion has always instilled fear in one and all. 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Br J Oral  Surg. 1979-80;17:227-31.   Zakrzewska JM, Boon EC. Use of safety dental syringes in British  and Irish dental schools. Br Dent J. 2003;195:207-9.    Open Access This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.  org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropri-  ate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.    The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in    a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.    Office-Based Anesthesia in Oral and  Maxillofacial Surgery-The American  Model and Training   Anxiety and pain control has been the center of dental health  provision from its inception. Dentists continue to practice  some form of pain and anxiety control throughout the world.  In the United States (US), Oral and maxillofacial surgery  (OMS) has maintained a unique privilege where the surgeon  is able to provide both anesthetic and surgical treatment for  most of the procedures that are completed in a setting outside  of the operation theater. The extensive, focused training  received during OMS residency in the delivery of anesthesia,  as well as continued education in anesthesia is central to this  privilege. The art and science of alleviating pain and anxiety  by providing office-based surgical treatment using various  anesthetic techniques is associated with tremendous respon-  sibility. Therefore, appropriate training along with local  licensure, credentialing, and continuous education is of para-  mount importance.   While the Commission on Dental Accreditation (CODA)  of the American Dental Association (ADA) stipulates stan-  dards in training OMS residents in anesthesia, American  Association of Oral and Maxillofacial Surgeons (AAOMS)  and state dental societies have developed parameters and  protocols that are enforced among practicing OMSs, ensur-  ing patient safety.   For the remainder of this chapter, the term ambulatory  anesthesia would refer to the provision of anesthesia outside  of a hospital operatory, such as a dental or an OMS office.  Generally, this would entail provision of “open-airway” deep   Oral & Maxillofacial Surgery, University of Cincinnati Medical  Center, OH, Cincinnati, USA    D. G. Krishnan  Oral & Maxillofacial Surgery, University of Cincinnati Medical  Center, OH, Cincinnati, USA    Oral & Maxillofacial Surgery, Cincinnati Children’s Hospital and  Medical Center, OH, Cincinnati, USA    © The Association of Oral and Maxillofacial Surgeons of India 2021    sedation with drugs delivered through an intra-venous (IV),  intra-muscular (IM) or inhalational routes.   The American Society of Anesthesiology (ASA) recog-  nizes four stages of anesthesia (Table 6.1) [1]. The most  common forms of anesthesia used in an ambulatory office  setting are mild-to-moderate sedation as well as deep seda-  tion/general anesthesia with the use of inhalational and intra-  venous agents. As defined by ASA, moderate sedation/  analgesia (replacing the term “Conscious Sedation,” which  has been condoned) is a medication-induced depression of  consciousness during which patients respond purposefully to  verbal commands, either alone or often accompanied by  light tactile stimulation. Other interventions are not required  to maintain a patent airway, while spontaneous ventilation is  adequate, and cardiovascular function is usually maintained.  Whereas deep sedation/analgesia is a drug-induced depres-  sion of consciousness during which patients cannot be easily  aroused but respond purposefully following repeated or  painful stimulation. The ability to independently maintain  ventilatory function may be impaired and may require assis-  tance in maintaining a patent airway. However, it is impor-  tant that the cardiovascular function is maintained.   Given that the process of sedation is a continuum, the  patient’s response is unpredictable. Hence, practitioners  should be able to rescue the patients whose level of sedation  becomes deeper than initially intended. An oral and maxil-  lofacial surgeon is well trained in airway management and  advanced life support.    6.2 _ Brief History of Anesthesia in OMS  Over several decades, Oral and maxillofacial surgeons have  been at the forefront of anesthesia and pain control among all  dental specialties and have been providing safe outpatient  anesthesia.   Nitrous oxide was produced by Joseph Priestly and was  termed as “laughing gas” by Humphrey Davy in eighteenth    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 | -15-1346-6_6    Table 6.1 Continuum of depth of sedation: definition of general anesthesia and levels of sedation/analgesia    century [2, 3]. It was first used as an anesthetic agent in den-  tal practice by Dr. Horace Wells [4] of Connecticut. He dem-  onstrated the use of nitrous oxide for dental extractions that  was aimed at the prevention of pain during surgery.  Unfortunately, he was dismissed due to lack of medical  background. His friend, William T G Morton [4], later dem-  onstrated the use of ether vapors as anesthetic for the removal  of a jaw tumor. Morton was therefore credited for the first  anesthetic (October 16, 1846; also known as Ether Day).  This solidified the foundation for the use of anesthetics in  dental practice.   A prominent step forward in the provision of safe ambula-  tory anesthesia was the development and further refinement  of the intravenous route of administration. It provided a safe  route for rapid delivery and titration of medications along  with giving the surgeon the ability to provide emergency  medications. The practice of intravenous techniques allowed  fast onset and recovery.   Adrian O. Hubbell [5] was critical in popularizing outpa-  tient general anesthesia among OMS. He completed his  training at Mayo Clinic and later demonstrated the safety of  administering barbiturate anesthesia in an outpatient setting.  He also advocated the utility and safety of recovering patients  on their side or abdomen postoperatively to prevent aspira-  tion of vomitus. Sylvan Shane [6] later reported on the use of  intravenous drugs (benzodiazepines) for inducing sedation  known as a “balanced” anesthetic. It was rapidly accepted  due to its property of anxiolysis as a sole agent.   Another drug that became popular was methohexital [7]  but was quickly overtaken by the introduction of Propofol  [8], which is currently the most favored primary agent. In  1989, Propofol was officially approved for use, and its ben-  efits related to the faster onset, improved recovery, and inher-  ent antiemetic activity were soon recognized.   It became evident soon that to continue the privilege of  administering outpatient anesthesia, it was important to  receive adequate formal general anesthesia training and to  maintain the highest standard of care. Today, Intravenous  drug anesthesia is the mainstay of providing sedation in the  outpatient setting of oral and maxillofacial surgery and has a  history of safety [9].   A majority of the OMSs in the US work in private practice  settings where ambulatory anesthesia is the mainstay of  practice. This has led to the development of a unique office  anesthesia model known as the Anesthesia Team model for  OMS practice [10]. This was originally described as the  operator-anesthetist model. That was a misnomer because in  reality the entire team involved in patient care is trained to  monitor and manage the patient under anesthesia in various  capacities.   In a typical setting, it is the surgeon who performs the  surgery and administers anesthesia. Apart from the surgeon,  two or more other team members are present in the room  (Fig. 6.1). At least one of these team members is required to  be BLS (Basic life support) trained. Most commonly, one  trained staff member observes the monitors, records drugs  and vitals, and helps with i.v. drug administration, while  another member acts as a surgical assistant. Assistant’s job is  to retract, suction, and irrigate during the surgery along with  helping in supporting the airway (Fig. 6.2). Often surgeons  employ a registered nurse with advanced cardiac life support  (ACLS) training in their offices as well. The entire team is  well versed with emergency equipment and is well trained to  handle an airway emergency by providing positive pressure  oxygen.   AAOMS strives to ensure that its members throughout the  country are in compliance with strict and mandated guide-  lines. It provides these guidelines through often-updated  Office Anesthesia Evaluation document made available  through the association. These guidelines are created by the  Committee on Anesthesia (CAN) of the AAOMS. This com-  mittee uses the latest evidence-based recommendations and  guidelines to make this document. This document is then  vetted by the ASA to ensure that it gets the highest level of  scrutiny and approval by that organization. This multilevel  peer-review process of the guidelines is important for ensur-    6 Office-Based Anesthesia in Oral and Maxillofacial Surgery-The American Model and Training 81    Fig. 6.1 Example of the office anesthesia team. The surgeon provides the  anesthesia and performs the procedure, one trained staff member sup-  ports the airway, and a second staff member is the surgical assistant    ing the safe delivery of anesthesia in the ambulatory OMS  setting.   Every AAOMS member (close to 10,000 members)  goes through a periodic office anesthesia evaluation pro-  cess by peers to ensure that each office and team is current  and well equipped to perform safe anesthetic practice in    Fig. 6.2 A dedicated registered nurse with ACLS training is often in  charge of monitoring the patient under sedation    their setting (Fig. 6.3). Failure to pass such an evaluation  leads to punitive action and inability to perform anesthe-  sia in the office setting until corrective actions are taken.  AAOMS, state dental societies, and third-party insurance  carriers take this process seriously. Public safety cannot  be compromised.   Name of Practitioner Evaluated General Anesthesia Permit Number (if applicable)  Location(s) Inspected Telephone Number    A. Personnel  1. ACLS Certificate (Please have doctor’s ACLS Certification available)  2. PALS Certificate (if appropriate)    3. Evidence of: one year advanced training in anesthesiology, Fellow of the American Dental Society of Anesthesiology,  Diplomate of the American Board of Oral and Maxillofacial Surgery, eligible for examination by American Board of  Oral and Maxillofacial Surgery, or Fellow of the American Association of Oral and Maxillofacial Surgeons    Have available three charts of patients who have been treated in your office with intravenous sedation or general  anesthesia.    1. An adequate medical history of the patient.  2. An adequate physical evaluation of the patient.    3. Anesthesia records showing: continuous monitoring of heart rate, blood pressure, and respiration using  electrocardiographic monitoring and pulse oximetry, and ventilation by capnography. In patients undergoing  inhalational anesthesia, preoperative and postoperative temperature monitoring, and if the procedure is longer  than 30 minutes, continuous temperature monitoring.    5. Evidence of continuous recovery monitoring, with notation of patient's condition upon discharge and person  to whom the patient was discharged.    6 Office-Based Anesthesia in Oral and Maxillofacial Surgery-The American Model and Training 83    Chapter 1 The OAE Program Component Society Guidelines and Evaluation Guidelines    . Operating Theater  a. Is the operating theater large enough to accommodate the patient on a table or in an operating chair adequately?    b. Does the operating theater permit an operating team consisting of at least three individuals to move freely about  the patient?    c. Does the operating theater allow easy access for emergency personnel and transportation equipment?  7. Operating Chair or Table    a. Does the operating chair or table permit the patient to be positioned so the operating team can maintain the  airway?    b. Does the operating chair or table permit the team to alter the patient's position quickly in an emergency?   c. Does the operating chair or table provide a firm platform for the management of cardiopulmonary resuscitation?  8. Lighting System   a. Does the lighting system permit evaluation of the patient's skin and mucosal color?    c. Is the backup lighting system of sufficient intensity and power for an adequate period of time to permit  completion of any operation underway at the time of general power failure?    9. Suction Equipment  a. Does the suction equipment permit aspiration of the oral and pharyngeal cavities?  b. Is there a backup suction device available?    a. Does the oxygen delivery system have adequate full-face masks and appropriate connectors, and is it capable  of delivering oxygen to the patient under positive pressure?    b. Is there an adequate backup oxygen delivery system?  11. Recovery Area (recovery area can be the operating theater)   e. Can the patient be observed by a member of the staff at all times during the recovery period?  12. Ancillary Equipment   a. Is there a working laryngoscope complete with an adequate selection of blades, spare batteries and bulbs?    i. Is there a pulse oximeter?  j. Is there a capnography monitor?    k. Is there adequate equipment for the establishment of an intravenous infusion?    D. Drugs  1. Vasopressor drug available?  Corticosteroid drug available?  Bronchodilator drug available?  Muscle-relaxant drug available?  Intravenous medication for treatment of cardiopulmonary arrest available?  Narcotic antagonist drug available?  Benzodiazepine antagonist drug available?    6 Office-Based Anesthesia in Oral and Maxillofacial Surgery-The American Model and Training 85   The facilities where ambulatory anesthesia is provided in  OMS practices are subject to stringent guidelines [11].  Specific building codes and local fire department regula-  tions have to be followed for installation of remote gases.  Proximity to a larger healthcare facility and access to  emergency personnel are of paramount importance.  Recommendations per Centers for Disease Control (CDC)  and prevention on controls for exposure to anesthetic gases  and other potential chemical hazards, as well as steriliza-  tion of the instruments and facilities are enforced. Office’s  fire safety and emergency protocols should be known by  all staff and easily accessible for reference. Telephone  numbers of the local ambulance service and nearest hospi-  tal should be clearly displayed and their location known to  all office staff.   Medical record keeping is paramount in current OMS prac-  tice. For the purpose of OMS procedures, proper electronic  records have to be maintained. This includes preanesthesia  assessment forms, i.e., history and physical evaluation, con-  sent forms, intraoperative anesthesia records, operative notes  as well as recovery records (Fig. 6.4). Anesthesia records  typically consist of vital signs (recorded every 5 min), type  and amount of drugs administered with time of administra-  tion, start and end times of anesthesia and surgery, surgeon  and other team members’ names, and details of complica-  tions and management, if any.    Every practicing AAOMS member agrees to a uniform peer  inspection of their properly equipped office and their tech-  niques and preparation for managing emergencies and com-  plications of anesthesia in the treatment of the OMS patient  in their office or outpatient setting.   In 1975, the AAOMS established the Office Anesthesia  Evaluation Program. This program was conceived, devel-  oped, and implemented by the AAOMS through its compo-  nent state societies to benefit the public, whom its members  serve. This ensures a level of safety to the practice of anes-  thesia in the OMS office, which is often outside a hospital or  other healthcare facility. Since 1990, AAOMS Bylaws  require official component societies’ constitutions and  bylaws to include provision for the fulfillment of an onsite  office evaluation based on the AAOMS Office Anesthesia  Evaluation Program as a prerequisite for active membership.    The office anesthesia evaluation is now required every  5-6 years for every AAOMS member.   AAOMS periodically offers an Office Anesthesia  Evaluation Manual [12] with the following intent—‘“AAOMS  Committee on Anesthesia developed the Office Anesthesia  Evaluation Manual to provide information that could aid oral  and maxillofacial surgeons in preparing themselves and their  offices for the management of anesthetic complications. It  presents scientific and clinical information and can serve as  a reference for the practitioner.’ The most recent evaluation  manual is available for purchase by the members in 2019.   In addition, a separate document called “AAOMS  Parameters of Care” [13, 14] is intended to reflect practice  considerations for 11 designated areas of oral and maxillofa-  cial surgery and is an additional guide for AAOMS members  to establish parameters of care for anesthesia in outpatient  facilities. The most recent version of this document was pub-  lished in 2017. The document provides complementary rec-  ommendations for the provision of safe sedation and  anesthesia in the office. Members are encouraged to review  both documents, which provide essential information on  contemporary OMS office anesthesia practice and practice  accordingly.    6.8 AAOMS National Simulation Program  AAOMS recognizes that the provision of anesthesia at an  OMS office is a team effort. It expects each member of the  team—from the surgeon to the assistants—to be highly  trained and qualified to address every anesthesia-related  situation that may occur during a surgical procedure. This  training is initiated in OMS residencies but is continuous  throughout the surgeon’s career, mandated by continuing  education and team exercised. Similar to professional sports  teams, successful oral and maxillofacial surgery teams train  as a unit to ensure they can seamlessly and quickly manage  an unexpected airway emergency. The most recent AAOMS  offering to help the office anesthesia team partners with  advanced simulation technology making it possible to train  surgeons and staff by simulating a full range of real-life  emergency airway situations [15]. This program allows par-  ticipants to practice and master critical techniques for  administering and monitoring office-based anesthesia; a  standardized approach that ensures that every participant  experiences the same simulated events. The program allows  for evaluation of each participant’s performance and can  pinpoint those areas that may benefit from additional train-  ing. The three-module program offers oral and maxillofacial  surgeons and their staff an effective method of assessing  their readiness to meet an office anesthesia emergency situ-  ation by practicing these in a low-risk, high-stake simula-  tion scenario.    6 Office-Based Anesthesia in Oral and Maxillofacial Surgery-The American Model and Training 87    The practice of office-based anesthesia depends largely on  the skillset of the assistants in the office as much as it does on  the surgeon leading the team. In an effort to elevate the edu-  cation and knowledge base of the other team members, a  program called the Dental Anesthesia Assistant National  Certification Examination (DAANCE) was implemented  nationwide. This is a continuing education program that  comprises 36 h of self-education and a computerized exam  to be completed in 6 months. This course is designed primar-  ily for OMS assistants. Upon successful completion of the  final examination, certification is provided.   The course is designed to cover important topics, including  general review of basic sciences, patient’s medical history  evaluation, basic knowledge on anesthetic drugs and tech-  niques, role of anesthesia equipment and monitoring, and cov-  ers basic maneuvers to handle office anesthesia emergencies.   This course is available to allied staff all year round to  register and complete. More and more states in the US are  now mandating courses like DAANCE or others to all team  members in an effort to keep the practice of ambulatory  anesthesia team model safe and viable in the OMS office.    OMS trainees in the US have a rigorous curriculum in anesthe-  sia. The Commission on Dental Accreditation (CODA) of the  American Dental Association (ADA) is the independent body  that accredits all residency training programs. This accredita-  tion is based on a peer-review process that enforces adherence  to training standards created and vetted by the CODA. The  educational standards for anesthesia read as follows:    4-3.1... Anesthesia Service: The assignment must be for a  minimum of 5 months, should be consecutive, and one of  these months should be dedicated to pediatric anesthesia.  The resident must function as an anesthesia resident with  commensurate level of responsibility.   Intent: The pediatric portion could include Pediatric  intensive care unit (PICU), Neonatal intensive care unit  (NICU), pediatric anesthesia service, or ambulatory  pediatric anesthesia. Oral and maxillofacial surgery resi-  dents rotating on the anesthesia service have levels of  responsibility identical to those of the anesthesia resi-  dents, and abide by the anesthesia department’s assign-  ments and schedules. Part of this time can be during  medical school as long as oral and maxillofacial surgery  trainee functions at the anesthesia resident level.    4-9... The off-service rotation in anesthesia must be sup-  plemented by longitudinal and progressive experience    throughout the training program in all aspects of pain and  anxiety control. The ambulatory oral and maxillofacial  anesthetic experience must include the administration of  general anesthesia/deep sedation for oral and maxillofa-  cial surgery procedures to pediatric, adult, and geriatric  populations, including the demonstration of competency  in airway management. Examples of evidence to demon-  strate compliance may include:    4-9.1... The cumulative anesthetic experience of each  graduating resident must include administration of general  anesthesia/deep sedation for a minimum of 300 cases. This  experience must involve care for 50 patients younger than  13. A minimum of 150 of the 300 cases must be ambula-  tory anesthetics for oral and maxillofacial surgery outside  of the operating room. Intent: The cumulative experience  includes time on the anesthesia rotation as well as anes-  thetics administered while on the oral and maxillofacial  surgery service. Locations for ambulatory anesthesia may  include dental school clinics, hospital clinics, emergency  rooms, and oral and maxillofacial surgery offices.  Examples of evidence to demonstrate compliance may  include:    4-9.2 ...In addition to general anesthesia/deep sedation,  the residents must obtain extensive training and experi-  ence in all sedation techniques.    4-9.3 ...The clinical program must be supported in part  by a core comprehensive didactic program on general  anesthesia, deep sedation, and other methods of pain and  anxiety control. The didactic program must include lec-  tures and seminars emphasizing:    4-9.4 ... Advanced Cardiac Life Support (ACLS) must be  obtained in the first year of residency and must be main-  tained throughout residency training and thereafter.    4-9.5... Each resident must be certified in Pediatric  Advanced Life Support (PALS) prior to completion of  training.    Adherence to these standards is strictly enforced ensuring  a standardized education in anesthesia to each OMS resi-  dent in training in the US.    The OMS planning an office-based anesthetic is trained to do  a thorough preoperative evaluation of the patient to deem  them fit for office anesthesia. Just as an anesthesiologist  would evaluate the patient for systemic disease, functional  capacity and medications along with a detailed anesthetic  history and physical examination to classify every patient  into an American Society of Anesthesiologists (ASA) status  (Table 6.2) [16], every OMS would do the same for formulat-  ing an anesthetic plan for the patient.   Ideally, ASA I and II patients are best suited for office-  based anesthetics. Careful preanesthetic patient evaluation is  critical in choosing the type and venue for the anesthetic.  This evaluation has the following essential steps:    e Reviewing and understanding patient’s medical, family,  social, surgical, and anesthetic history through question-  naire and interview.    This detailed preop evaluation gives the OMS the knowl-  edge to classify all according to the ASA classification and  adequately plan for an appropriate anesthesia technique.    Provision of anesthesia in the OMS office requires that mon-  itoring is done according to the ASA standards and more.   This includes the following minimal time-stamped moni-  toring and documentation [17].    Noninvasive monitoring of blood pressure every 5 min  Continuous ECG monitoring   ASA II A patient with Mild diseases only without substantive  mild systemic functional limitations. Examples include  disease (but not limited to): Current smoker,   social alcohol drinker, pregnancy,  obesity (30 < BMI < 40), well-  controlled DM/HTN, mild lung disease   ASA III A patient with Substantive functional limitations; one  severe systemic or more moderate-to-severe diseases.  disease Examples include (but not limited to):   Poorly controlled DM or HTN, COPD,  morbid obesity (BMI >40), active  hepatitis, alcohol dependence or abuse,  implanted pacemaker, moderate  reduction of ejection fraction, ESRD  undergoing regularly scheduled dialysis,  premature infant PCA < 60 weeks,  history (>3 months) of MI, CVA, TIA,  or CAD/stents.   ASA IV A patient with Examples include (but not limited to):  severe systemic Recent (< 3 months) MI, CVA, TIA, or  disease that is a CAD/stents, ongoing cardiac ischemia  constant threat to or severe valve dysfunction, severe  life reduction of ejection fraction, sepsis,   ASA VA moribund Examples include (but not limited to):  patient who is not Ruptured abdominal/thoracic aneurysm,  expected to massive trauma, intracranial bleed with  survive without mass effect, ischemic bowel in the face  the operation of significant cardiac pathology or    5. Ability to measure temperature, i.e., very essential in a  setting where Malignant Hyperthermia (MH) triggering  agents are in use.    Majority of OMS offices now use monitor units (Fig. 6.5)  that interface directly with an electronic health record. The  entire team is clued into monitoring with a staff member  often dedicated to only monitoring the patient.   All patients receive supplemental oxygen before, during,  and after the procedure. Most facilities have a separate recov-  ery area with the same monitors, although there are several  offices that recover in the operatory. The goal is the improve-  ment of efficacious monitoring to establish the safe perfor-  mance of anesthetic without the need for a separate anesthesia  provider. It is imperative to have a meticulously trained team  to allow for continuous monitoring, thus facilitating immedi-  ate recognition of changes in patient’s vital signs. A properly  evaluated and selected patient is unlikely to have a catastro-  phe in the OMS anesthetic, but when an untoward event does  occur, it is often a respiratory event.    6 Office-Based Anesthesia in Oral and Maxillofacial Surgery-The American Model and Training 89    Data available from closed claims cases from the OMS  National Insurance Corporation (OMSNIC) allow us as a  specialty to audit the near-misses and tragic outcomes from  our offices. The data suggest a strong correlation between  airway-related failure and adverse events in the open-airway  anesthetic techniques. The emphasis is on monitoring of    Fig.6.5 Example of monitor commonly used in oral and maxillofacial  surgery anesthetic administration. The single unit clearly displays the  electrocardiogram, noninvasive blood pressure monitor, oxygen satura-  tion, and end-tidal carbon dioxide    both ventilation and oxygenation to allow adequate monitor-  ing of the respiratory system during anesthesia. This can be  achieved by using a pulse oximeter, which is a device that  measures oxygen saturation and provides an indirect indica-  tion of oxygenation. Recently, AAOMS recommended a  newer ASA standard monitoring of ventilation with continu-  ous capnography. Although chest movements are a reliable  method but are least exact, hence the addition of capnogra-  phy. Most OMSs use a pretracheal/precordial stethoscope  (Fig. 6.6) to auscultate while the patient is sedated.   Historically, pulse oximetry has been used for respiratory  monitoring. But due to its limitation in lacking real-time  responsiveness to major respiratory events like airway obstruc-  tion or respiratory depression, there was an imminent need to  incorporate a different parameter to provide a real-time assess-  ment. Thus was developed capnography [18], which is the  noninvasive measurement of the partial pressure of carbon  dioxide (CO2) from the airway during inspiration and expira-  tion. It can provide real-time sensitivity to early changes in  ventilation and is reliable even in low-perfusion states.   Although, in the nonintubated sedated patient, there is  loss of CO2 through the nose and mouth, and thus requires  modification of the collection cannula, it still provides valu-  able clinical information on patient’s ventilation during  sedation.   It cannot be stressed enough how critical it is to manage  intraoperative airway and monitor respiratory status.  Ventilation is monitored by inspection of chest movement by  the assistants, monitoring of capnography as well as auscul-    Fig.6.6 (a, b) Pretracheal/precordial stethoscope used by the surgeon to auscultate while the patient is sedated    tation with a precordial stethoscope. The newer Bluetooth  models of the precordial stethoscope allow wireless speakers  that allow the entire team to listen to the patient’s respiratory  patterns.   Now with multiple modalities such as a real-time capnog-  raphy tracing, listening to breath sounds with high fidelity,  OMS team has an opportunity to assess and act promptly on  potential airway threats even before the adverse respiratory  event comes to light. With these available modalities, along  with surgeon’s experience and developed senses, anticipa-  tion and prediction of an impending laryngospasm or bron-  chospasm prompts the team to act preemptively. Even before  a drop in oxygen saturation or loss of waveform on capnog-  raphy becomes apparent, both the depth and rate of breathing  as well as the cessation of breathing can be promptly  recognized.    Despite several preventive modalities available to the OMS  performing anesthesia, emergencies are bound to happen.  The unit must be prepared to handle airway and other emer-  gencies. All the anesthesia providers should be exceptionally  familiar with emergency airway equipment that must be  readily accessible in both the operating suites and the recov-  ery area [11].   Emergency airway equipment must include full face  mask, bag-valve-mask device capable of providing positive  pressure ventilation, oral and nasopharyngeal airways,  supraglottic airway devices, endotracheal tubes, and laryn-  goscope and cricothyrotomy kit. All these equipment should  be available in both pediatric and adult sizes. The entire staff  should have periodic in-office training to familiarize them-  selves with the equipment and their use. Apart from emer-  gency airway instruments, all offices are required to have  either a basic monophasic defibrillator or automated external  defibrillator.    In addition to oxygen, most OMS offices utilize other gases  such as nitrous oxide and inhalational anesthetics as well as  air. The oxygen delivery system should be able to deliver  metered oxygen to the patient under positive pressure. A  standard fail-safe mechanism along with scavenging system  should be part of all gas delivery machines installed in the  office. This prevents delivery of any hypoxic amount of  gases. To prevent the accidental administration of an incor-  rect gas, the gas outlets used should be pin-indexed. The gas  delivery machines also are mandated to have periodic cali-    bration records, which should be maintained with proper  documentation stored at a known location. Anesthesia equip-  ment, including ventilators, are similarly required to have a  periodic inspection by biomedical engineers. The OMS  office is responsible for ensuring this happens and the office  anesthesia evaluation is a mechanism to keep a check on this.    As trivial as it may seem, the office suction unit (central and  portable) is an integral part of both the normal and emer-  gency functions of that office. A portable suction unit must  be readily accessible in the operatory and recovery area in  case of unanticipated power failure or central suction pump  failure. Again, routine maintenance of the suction system  and its documentation is required.    Most OMS offices have a postoperative recovery unit sepa-  rate from the operatory that allows unobstructed patient  observation. The design of this area must allow resuscitation  and management of the patient during an emergency. The  recovery area should have a suction system, oxygen delivery  system, all appropriate monitors and emergency equipment  as detailed earlier. It is also the responsibility of the recovery  nurse to document the patient’s recovery from anesthetic to  deem their fitness to leave the office. A recovery checklist  such as the Modified Aldrete Scale is useful in making this  determination.    Training in anesthesia exposes the oral and maxillofacial sur-  geon to the different modalities of anesthesia from light to  deep sedation. As described before, levels of anesthesia are a  continuum (Table 6.1). The effects of different drugs and  techniques may vary between individuals. Patients may  achieve deeper or lighter levels of anesthesia than anticipated  based on their unique metabolic responses to the different  anesthetics administration. The OMS team is prepared to  anticipate these differences in responses and intervene  accordingly.   The techniques utilized to get to different levels of anes-  thesia include inhalational anesthesia, oral anesthetic tech-  nique, parenteral anesthesia, and local anesthesia. Regardless  of the technique employed, the goals of each of these tech-  niques are to reduce anxiety, establish cooperation, amnesia  and analgesia, ensuring comfort and hemodynamic stability.  In order to choose the level of anesthesia, one should con-    6 Office-Based Anesthesia in Oral and Maxillofacial Surgery-The American Model and Training 91    sider the age of the patient, level of anxiety and ability to  cooperate, detailed medical history, and prior anesthesia  experience.    Oral or nasal route of delivery of drugs is the least threaten-  ing route of administration of anesthesia. While some anx-  iolysis is achieved via this modality, it is rarely used to  achieve deeper levels of anesthesia. Often the oral route of  sedation is used as a premedication prior to IV access in an  uncooperative patient. Various ingestives such as syrups,  popsicles, needleless syringes, other creative methods are  employed to get the patient to consume the medication.  Dosing is adjusted in such a way that a higher dose of the  drug may be administered in a limited volume to prevent the  likelihood of aspiration. Despite that, a crying child or a  coughing adult may end up aspirating the medication. The  other disadvantages of this technique include a slow onset  and variable response to the action of the drug as well as an  unpredictable recovery pattern. In an uncooperative patient,  patient compliance will limit oral or nasal administration of  any drug. Additionally, oral dosing is often empiric with  almost predictable erratic absorption. Titration of the drug is  difficult via this route.   Yet, it remains a convenient mode of administration,  requiring very little training to deliver, and any adverse reac-  tions are slow to the onset and usually less severe and man-  ageable. In the US, a medical provider providing oral  sedation in the office does not have an increase in their mal-  practice premiums because of this practice. In contrast, prac-  titioners of general anesthesia have higher malpractice  coverage due to the inherent risks of that practice.   An ideal oral medication must be able to provide rapid  absorption, must have a rapid onset, and must have a high  therapeutic index allowing rapid and predictable recovery.   The following are the drugs most commonly used in oral  sedation techniques:    Oral sedation techniques are primarily useful in the OMS  as a premedication tool. An orally sedated patient is likely to  accept a mask or an IV for further induction of anesthesia.  Several minor procedures, however, can be performed with  oral sedation and good local anesthesia alone.    Hubbell [5] was known to promote the use of intravenous  thiopental anesthesia. It was eventually replaced by the  shorter-acting barbiturate methohexital. This became the pri-  mary agent used for office-based anesthesia for multiple  decades. A shortage in supply of methohexital and an  increased use of Propofol [8] in the operating theater setting  prompted an adaptation of the use of that drug in the office-  based anesthetic technique. The basic technique for deep  sedation and general anesthetic in the nonintubated patient in  the OMS office typically employs a cocktail of medications  under strict ASA-mandated guidelines for monitoring with  the personnel as described earlier.    e A benzodiazepine such as Midazolam for anxiolysis,  amnesia, sedation, and hypnosis   e A sedative hypnotic such as Propofol. It also acts as an  adjunct antiemetic agent.   e Adjuvant drugs such as dexamethasone for prevention of  postoperative edema and nausea and vomiting.    Most of these medications are characterized by their abil-  ity to have a rapid onset and offset. Medications such as  Propofol rapidly redistribute and metabolize and are elimi-  nated from the system. The combination of these medica-  tions often results in a cumulative effect of sedation and  hypnosis in addition to central analgesia. Discomfort from  the administration of local anesthesia is often obtunded by  this level of sedation. Patients maintain their ventilation and  careful monitoring of their vital signs and protection of their  airway allows for smooth sedation. The surgeon who is per-  forming the procedure is in close proximity to the patient’s  airway understanding its minute undulations and sensing the  level of the patient’s sedation and acting preemptively to  either prolong or discontinue the sedation. It is an art and  science that is built on years of training and experience.   The dosing of these medications is based on the patient’s  ideal body weight. The administration of these medications  is through a continuous intravenous catheter infusion with an  appropriate IV fluid. Typically, a 20- or a 22-gauge catheter  is inserted into a peripheral vein in the upper extremity. Most  OMSs practice the bolus technique, which introduces incre-  mental doses of each medication, titrated to effect. Infusion  pumps are often utilized in longer cases, while shorter cases  of sedation seldom require infusion.    The ninth edition of the AAOMS Office Anesthesia Evaluation  Manual [12] provides a detailed list of medications that can be  used during anesthetic emergency. OMS offices are recom-  mended to have a refrigerator designated for medications  requiring cold storage. Pharmacy boards of different states  control the storage and distribution of these drugs.   Listed are suggested drugs used in the event of anesthetic  emergencies:    ¢ Cardiovascular medications: Oxygen, Atropine,  Nitroglycerin, Dopamine, Epinephrine, Dobutamine,  Ephedrine, Phenylephrine, Lidocaine, Propranolol,    Hydrocortisone sodium succinate or Methyl] prednisolone  sodium succinate (Solu-Medrol), Glycopyrolate (Robinul),  Diazepam (Valium), Midazolam (Versed), Albuterol  inhaler, Succinylcholine (Anectine), Morphine sulfate,  Dantrolene (Dantrium), Lidocaine, Nonenteric-coated  aspirin, Famotidine (Pepcid), Diphenhydramine (Benadryl)    Dental anesthesia is an ADA-recognized specialty in the US as  of 2019. Several dental practitioners, including OMSs, prac-  tice anxiolysis and sedation in their offices, outside a hospital    operating suite and without a separate anesthesia provider. The  concerted efforts by various interested parties to politically  organize and better protect our intellectual and political inter-  ests in the discipline make this practice a reality in the US.   To ensure the commitment to patient safety, the AAOMS  and its Board of Trustees have embraced a multipronged  approach:   ¢ a devotion to the anesthesia team approach and develop-  ment of the DAANCE program for the assistants   ¢ the development of anesthesia and emergency manage-  ment simulation programs such as Basic Emergency  Airway Management [BEAM] and Office-Based Crisis  Management [OBCM] are some examples of some of this  commitment.    The AAOMS developed an Anesthesia Safety Conference  for our own specialty that was held on April 27, 2017, at the  American Society of Anesthesiologists headquarters in  Schaumburg, Illinois. Representatives of the ASA as well as  representatives of the appropriate disciplines of dentistry  attended this meeting. In April 2019, a second patient safety  conference focusing on pediatric sedation was organized at  the AAOMS headquarters in Rosemont, Illinois.   By staying on the forefront of office-based anesthesia and  by enforcing the highest standards of safety in patient care,  OMS as a specialty has become stalwart in this arena.  Continued positive momentum with nationwide simulation  workshops and a mobile application supporting the office  anesthesia evaluation will enhance our role as leaders in  ambulatory anesthesia in our offices. The rapid response and  emergency system and the healthcare infrastructure in the  US allows for OMSs in this country to adapt this technique  and methodology into their practices almost effortlessly. In  other parts of the world, this may not be a model that is easy  to replicate.    1. American Society of Anesthesiologists (ASA). Continuum of depth  of sedation: definition of general anesthesia and levels of sedation/  analgesia. (Approved by the ASA House of Delegates on October  13, 1999 and last amended on October 15, 2014). Available at:  https://www.asahq.org/standards-and-guidelines/continuum-of-    Office-Based Anesthesia in Oral and Maxillofacial Surgery-The American Model and Training    . Bicentenary of nitrous oxide. Br Med J. 1972 May 13;2(5810):367-    and the royal institution. Am J Physiol Lung Cell Mol Physiol 2014  Nov 1;307(9):L661-L667.    terfactual narrative about Crawford W. long, Horace Wells,  Charles T. Jackson, and William T. G. Morton. AANA J 2015  Dec;83(6):410-415. PubMed PMID: 26742335.    sia. Part I: Methohexital is superior. J Oral Maxillofac Surg 1995  Jul;53(7):811-815. Review. PubMed PMID: 7595796.    thesia. Part I: Propofol is superior. J Oral Maxillofac Surg 1995  Jul;53(7):816-820. Review. PubMed PMID: 7595797.    gery office: a look Back, where we are now and a look ahead. J Oral  Maxillofac Surg 2018 May;76(5):917-925. Review.   Drew SJ. Oral and maxillofacial surgery team anesthesia model and  anesthesia assistant training. Oral Maxillofac Surg Clin North Am  2018 May;30(2):145-153. Review.   Chung WL. Anesthesia equipment for the oral and maxillofa-  cial surgery practice. Oral Maxillofac Surg Clin North Am 2013  Aug;25(3):373-383.   American Association of Oral and Maxillofacial Surgeons  (AAOMS). Office anesthesia evaluation manual. 9th edition. 2018.  Available at: http://www.aaoms.org.   American Association of Oral and Maxillofacial Surgeons  (AAOMS). Parameters of Care: AAOMS Clinical Practice    Guidelines for Oral and Maxillofacial Surgery (AAOMS ParCare)  Sixth Edition 2017. Patient assessment. Available at: https://www.  aaoms.org/images/uploads/pdfs/parcare_assessment.pdf   American Association of Oral and Maxillofacial Surgeons  (AAOMS). Parameters of Care: AAOMS Clinical Practice  Guidelines for Oral and Maxillofacial Surgery (AAOMS ParCare)  Sixth Edition 2017. Anesthesia in outpatient facilities. Available at:  https://www.joms.org/article/S0278-239 1 (17)30488-3/pdf   Todd DW, Schaefer JJ 3rd. The American Association of Oral and  Maxillofacial Surgeons Simulation Program. Oral Maxillofac Surg  Clin North Am 2018 May;30(2):195-206. Review.   ASA Physical Status Classification System. Developed By:  ASA House of Delegates/Executive Committee, Last Amended:  October 15, 2014 (original approval: October 15, 2014).  Available at: —_https://www.asahq.org/standards-and-guidelines/  asa-physical-status-classification-system.    basic anesthetic monitoring. Developed By: Committee on  Standards and Practice Parameters (CSPP) Last Amended:  October 28, 2015 (original approval: October 21, 1986).  Available at: —_https://www.asahq.org/standards-and-guidelines/  standards-for-basic-anesthetic-monitoring.   Farish SE, Garcia PS. Capnography primer for Oral and maxillo-  facial surgery: review and technical considerations. J Anesth Clin  Res 2013 Mar 18;4(3):295. PubMed PMID: 24459603; PubMed  Central PMCID: PMC3897173.    Surgeons (AAOMS). Office-Based Anesthesia Provided by the Oral  and Maxillofacial Surgeon. 2016. Available at: https://www.aaoms.  org/docs/govt_affairs/advocacy_white_papers/advocacy_office_  based_anesthesia_whitepaper.pdf    Open Access This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.  org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropri-  ate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.    The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in    a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.    Rebecca Jacob, Subramanyam S. Mahankali,  Renita Maria, Suman Ananathanarayana, Garima Sharma,   Maxillofacial surgery encompasses a wide range of proce-  dures on the head and neck, combining oral and facial proce-  dures with the ear, nose and throat (ENT), plastic surgery,  neurosurgery and base of skull specialities. It ranges from  simple dental extractions to complex reconstructive and free  flap surgery.   Patients of all age groups may present for maxillofacial  surgery. The main issues involve managing a shared airway;  providing good access to head, neck and oral cavity. The  management of difficult airways and measures to reduce tis-  sue bleeding and oedema, both intra- and post-operatively  pose a unique challenge to the anaesthetist. Good communi-  cation between all members of the team is essential [1].   All patients should be assessed preoperatively and an anaes-  thetic plan should be formulated as these patients may have  a suspected or a known difficult airway or are undergoing  complex or prolonged surgery. Patients may give the history  of poor oral intake and nutritional state due to pain, dyspha-  gia and odynophagia. If dyspnoea is present, it should be  evaluated as to whether it is cardiac or respiratory in origin.    Electronic Supplementary Material The online version of this chap-  ter (https://doi.org/10.1007/978-981-15-1346-6_7) contains supple-  mentary material, which is available to authorized users.    R. Jacob  - S. S. Mahankali - R. Maria - S. Ananathanarayana -  G. Sharma   Department of Anesthesiology, Columbia Asia Referral Hospital,  Yeshwantpur, Bangalore, Karnataka, India    M. Thomas  Department of Anesthesiology, Regional Cancer Centre, Medical  College Campus, Thiruvananthapuram, Kerala, India    © The Association of Oral and Maxillofacial Surgeons of India 2021    Previous surgeries, medication history and comorbidities  diagnosed earlier should be noted. Medication history is  important in all patients, especially elderly patients with car-  diac, respiratory or renal involvement. It is also important to  ascertain whether the patients have any comorbid ailments  like hypertension, diabetes, thyrotoxicosis or myxoedema, a  history of epistaxis or bleeding tendency and use of antico-  agulants [2, 3].    7.2.1 Patients on anticoagulants  Patients on anticoagulants may present for emergency or  elective surgery. The type of anticoagulant the patient is on  should be noted during pre-operative assessment. Risk of  peri-operative bleeding versus thrombosis on discontinua-  tion of anticoagulants should be stratified and accordingly  discontinued or bridged with preferably unfractionated hepa-  rin or low-molecular-weight heparin prior to elective sur-  gery. Usually, three half-lives (Tj) discontinuation of  anticoagulants prior to surgery is considered optimal to pre-  vent blood loss (Table 7.1) [3].   In emergency situations, the main goals are discontinua-  tion of anticoagulation, delaying semi-urgent procedures as  appropriate and employment of reversal strategies like plate-    Table 7.1 Recommendations for discontinuation of anticoagulation  prior to elective surgery   Apixaban Low bleed risk >24 h  High bleed risk >48 h    American College of Chest Physician 2012 Guidelines published in  Chest, the RE-LY trial published in Circulation 2014, the ROCKET AF  trial, and the manufacturer’s recommendations    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1-15-1346-6_7    let transfusions, fresh frozen plasma, vitamin K antagonists,  and prothrombin complex concentrates.   The previous anaesthetic charts should be reviewed for  the techniques used, ease of mask ventilation, best direct  laryngoscopy grade, Endotracheal tube (ETT) size used, and  any difficulties encountered and should be noted. The airway  of previously operated patients may be altered due to previ-  ous surgeries and/or oedema, so this should be taken into  account while reviewing the anaesthetic and follow-up  records of the patient. If nasal intubation is required, one  should enquire about nostril patency (history of nasal polyps  or deviated septum). Contraindications to the use of con-  trolled hypotension, e.g. cerebrovascular, reno-vascular and  moderate-to-severe coronary artery disease should also be  assessed. Specific attention should be given to the needs of  each class of patient.    Patients with head and neck cancer sometimes constitute the  most challenging patients. Their upper airway may be seri-  ously distorted, and they may have tracheal stenosis or hard-  ening and fixation of the soft tissues due to radiotherapy.   In these patients, documents concerning previous surger-  ies, radiation and chemotherapy should be studied. The dif-  ficult airway may have been encountered, tracheostomy and  residual tracheal stenosis, limited mouth opening, and neck  extension may have been recorded [4].   Symptoms such as hoarse voice, stridor, and dyspnoea  will indicate whether there is airway compromise due to ste-  nosis, tumour, nerve damage or oedema. Post radiation, the  patients may have tissue fibrosis with limited mouth opening  or neck extension. Make a note of chemotherapy drugs, dura-  tion and interval since the last cycle of chemotherapy.    Trauma patients require a thorough history of the mechanism  of injury, which would indicate intracerebral or spinal injury.  Drug and/or alcohol ingestion is often a contributory factor,  and 15% have other injuries. There is also potential for inju-  ries to other organs and massive blood loss. Cervical spine  injury occurs in 5—10% of patients with blunt trauma to the  head and face. Therefore, the patient should be evaluated  from ‘head to toe’ [5].    Consider age, weight, prematurity, feeding, nutritional status  and position during sleep. In patients with craniofacial    abnormalities, look for associated syndromes such as Pierre  Robin sequence or Treacher Collins syndrome as in addition  to a difficult airway these patients may have involvement of  other systems, such as cardiac, as a part of the syndrome,  which will require specialist consultation [6].    Infection of dental and facial structures commonly leads to  erythema and swelling of tissues. This can result in obstruc-  tion of airway and difficulty in airway management. Toxic  airways (e.g. Ludwig’s angina, dental cysts and osteomyeli-  tis) with spreading infection often present as acute emergen-  cies and may pose an extreme airway maintenance challenge.  Direct laryngoscopy due to trismus, tissue distortion, oedema  or abscess cavity and pus may not be possible and other  means of securing the airway must be considered [4]  (Fig. 7.1a, b).   A detailed airway assessment based on criteria in the ‘L-E-  M-O-N’ method would help to stratify the risk of difficult  intubation. The ‘LEMON Law’ can be used to quickly  assess for potentially difficult airways [7]. A total score of  10 can be given as per the criteria and higher scores are  associated with poor glottic visualization and difficult  intubation.   In paediatric patients, the Mallampati score does not  accurately predict a poor view of the glottis and there are no  standard values for the thyromental and horizontal length of  the mandible. Thus, an adaptation is required, and this is  found in the ‘“COPUR SCALE’ (Table 7.3) [7, 8].    e¢ Whether mask ventilation would be possible after  induction of General Anaesthesia (GA).   e Whether it would be possible to use a supraglottic  airway as a rescue device.   e Possibility and accessibility of a surgical airway in  case of a dire emergency.   Look for pallor, icterus, cyanosis, clubbing, lymphadenopa-  thy and oedema as well as the general nutritional status.  Follow this up with pulse rate, blood pressure, respiratory  rate, oxygen saturation, signs of dehydration, and responses  denoted as AVPU-—Alert, Verbal, Pain, Unresponsive.   AVPU is a simplified version of the Glasgow Coma Scale  (GCS), which is easy to remember and apply to patients  (Table 7.4) [9, 10]. It consists of four possible stages. When  recording AVPU, it is important to document the time the  observation was taken and to track any changes over time as  this will help monitor the progress of the patient (Table 7.4).   Apart from these, specific systemic examination, includ-  ing cardiovascular, respiratory, per-abdomen and central ner-    vous system, should be done and if in any doubt a specialist  should be consulted.   There are various scales used to record a patient’s level of  consciousness. One of the most detailed is the GCS, which is  used worldwide (Table 7.5) [9, 10]. The GCS is a reasonably  complicated system, which, unless you use regularly, can be  difficult to remember and apply correctly.   In addition to routine blood tests like complete blood counts,  kidney function tests, blood sugars, coagulation profile,  serology, blood grouping and cross-matching is required for  major surgery.   Chest X-ray helps in visualising any pathology in the  lungs. It may also reveal tracheal deviation. X-ray soft-tissue  neck, airway ultrasound, computerized tomography (CT),  and magnetic resonance imaging (MRI) scans may be help-  ful in cancer, infections, abscesses or trauma cases.   For cancer surgery, a nasoendoscopy & indirect laryngos-  copy provides valuable information about the upper airway  anatomy.   Electrocardiogram (ECG), echocardiogram, cardiopul-  monary exercise testing or pulmonary function tests are  required if there are symptoms or signs of cardiorespiratory  disease.   Tip of uvula visible — 1  Uvula partially visible — 2  Uvula concealed/soft palate  visible — 3    8-10: Laryngeal help may be required  12: More difficult, may be less traumatic  14: Difficult intubation, fibre optic or other advanced technique may    questions but moves or  cries out in response to  painful stimuli such as  pinching the skin or  earlobe    when painful  stimuli are  received such as  pinching the nail  bed   Flexion withdrawal to pain  Abnormal flexion (decorticate)  Abnormal extension (Decerebrate)  No response    This is essential in all cases but especially so in patients who  may have dramatic cosmetic changes or are undergoing can-  cer surgery like hemi-mandibulectomy. The possibility of  tracheostomy and loss of voice must also be discussed with  empathy. Video counselling may be resorted to in case of  need.   Any patient above the age of 18 years may give consent for  surgery and anaesthesia. In the case of patients younger than  18 years, consent must be obtained from a parent or guardian  after full explanation of procedures. The consent must be  documented and signed by both the person taking the con-  sent and the person giving the consent.   Should be with a trained health care worker especially if the  patient has been given a sedative premedication. It is advis-  able for a parent or guardian to accompany younger children  to the OT.    All documents pertaining to the case must be handed over to  the OT personnel and the handover documented.    7.5.1 Before Induction (Figs. 7.2, 7.3, 7.4, 7.5,  7.6, 7.7, and 7.8) [6]   e Ensure you have adequate help and each one knows what  is expected of him/her   ¢ If intubation is difficult do not try more than 2-3 times  with any one method (you will precipitate oedema and  make matters worse)    ¢ Continue oxygenation with spontaneous respiration and  wake up the patient if intubation is unsuccessful    More patients have died from lack of oxygen than from  lack of an endotracheal tube!   Please see Chap. 42 in this book to read about avoidable  human errors for a safer patient care. (A case of loss of air-  way is discussed in Chap. 42).    7.5.2 Induction  Anaesthesia may be induced either intravenously or with an  inhalational agent. The choice of technique depends on:    In young patients belonging to ASA (American Society of  Anesthesiologists) Grade I and II, standard monitoring will  suffice. Invasive arterial blood pressure monitoring may be  required if controlled hypotension is planned or if comor-  bidities warrant. Monitoring of temperature is required in  children and those undergoing prolonged surgeries like cor-  rective LeFort osteotomies. Urinary catheterization may be  required during prolonged surgeries.    The method of securing the airway should be discussed with  the surgeon. This depends on:    ¢ Patient factors, such as age, obesity, pan-facial trauma or  anticipated difficult airway   ¢ Site of operation may require oral or nasal intubation with  specially configured tubes.    Fig. 7.3 (a) Nasal airway, (b) Oral airway, (c) Ventilation mask and (d) Laryngoscope blades    Simple intraoral operations with no anticipated difficult  airways can be done with standard nasal intubation or oral  intubation under general anaesthesia with endotracheal tube  pushed to the side opposite of surgery. Use of specially pre-  formed tubes like RAE tubes and Reinforced/Armoured tube  can be used to give good access to the surgical area (Figs. 7.4    and 7.5). However, major corrective surgeries will require  the oral cavity to be empty and hence warrant nasal intuba-  tion, submental intubation or a tracheostomy. Anticipated  non-obstructed difficult airway as assessed by history and/or  examination or suspected (cervical) C-spine injury should be  managed with awake fibre optic bronchoscopy or blind nasal    intubation. The safety of awake intubation relies on the  maintenance of spontaneous breathing, and the ability to  stop and perform a different technique, such as awake trache-  ostomy, if intubation is unsuccessful. Most anaesthesiolo-  gists prefer the nasal route for fibre optic intubation, as it is  technically easier. For this, the patency of the nostril should  be assessed preoperatively, and roomier nostril should be  chosen and prepared with vasoconstrictor drops like oxy-  metazoline hydrochloride.   Sedation may enhance the acceptability of awake fibre  optic intubation. Dexmedetomidine infusion [11] serves  this purpose very well. Airway instrumentation can be  facilitated by local anaesthetic topicalisation of airway  either by means of lignocaine nebulisation or ‘spray as you    go’ technique and/airway blocks (glossopharyngeal, supe-  rior laryngeal and recurrent laryngeal nerve blocks) [12].  An  antisialogoguelike glycopyrrolate administered  30-45 min prior will reduce the secretions and will facili-    tate awake fibre optic intubation. Airway blocks may not  be an option to facilitate awake intubation in cases such as  extensive pan-facial fractures or post-radiation fibrosis of  the neck. Fibre optic intubation may be impractical in case  of oro-maxillofacial trauma if associated with severe air-  way bleeding that can obscure visibility and other options  such as tracheostomy under local anaesthesia (LA) should  be considered.   The traditional ‘blind nasal intubation’ is rarely employed  these days but may be used if a fibre optic scope is not avail-  able or not possible (Video 7.1).   During long surgery and if ventilated in the post-operative  period, the Endotracheal (or tracheostomy) cuff pressure  should be measured using an aneroid manometer. A pressure  of 20-30 cm of H,O is considered as standard in adults.   In supraglottic obstruction—associated with stridor and  respiratory distress, as in case of upper airway trauma, rap-  idly expanding infections like epiglottitis, Ludwig’s angina,  etc. awake fibre optic bronchoscopy and intubation may not  be the right choice. In such a situation, an awake tracheos-  tomy under local anaesthesia must be considered.    Several varieties of supraglottic airway devices are available  (Fig. 7.9). However, these are not ideal devices for oro-  maxillofacial surgeries requiring the oral cavity to be empty,  but can be lifesaving as rescue devices in ‘cannot ventilate,  cannot intubate’ situations to ventilate a patient until the  definitive airway is secured. However, a flexible reinforced  LMA can be used for simple dental extractions and nasal,  zygomatic and superficial facial surgery. However, obstruc-  tion and dislodgement can occur, especially when the man-  dible is moved.   Paediatrics: [6] Children will not co-operate for awake fibre  optic intubation. Hence, in such cases, the airway can be  secured after inhalational induction without relaxation after  establishing IV access. A nasopharyngeal airway may be  passed gently into one nostril and connected to a breathing  circuit while monitoring the end-tidal carbon dioxide  (EtCO,) and continuing the anaesthetic and oxygenation via    the airway. The other nostril may now be prepared with a  vasoconstrictor and local anaesthetic and used for fibre optic  intubation (Fig. 7.10).    7.6.1 Retromolar and Submental Intubation  These techniques were developed as alternatives to tracheos-  tomy in maxillofacial surgeries requiring intra-operative  inter-dental fixation for malocclusion correction like com-  minuted fracture of the mid-face or the nose, where nasal  intubation is contraindicated.   Pre-operatively check the adequacy of the retromolar space. This  is done to prevent kinking of the endotracheal tube in retromolar  space by insinuating the index finger behind the third molar and  asking the patient to clench his teeth. The patients’ airway is then  intubated by the conventional method and the ETT is pushed in  the retromolar space and brought out from the angle of the mouth  and connected to the ventilator. The spiral reinforced/armoured  ETT is preferred as it is kink resistant (Fig. 7.11).   (See additional reading material on submental intubation  given at the end of the chapter).   Just like retromolar intubation, it also requires the use of  a spiral reinforced/armoured ETT in order to prevent the  tube from kinking during its usage. Following conventional  orotracheal intubation, a 2-cm incision is made lateral to  the midline between the chin and the angle of the mandible  and an opening is made in the floor of the mouth by the  surgeon, avoiding the submandibular salivary glands. The  machine end of the ETT without the connector is pulled  through the tunnel, using gentle rotational movements.  Following this manoeuvre, the tube is connected to the ven-  tilating machine and sutures are used to fix the tube in posi-  tion. If the procedure of disconnecting the ETT is long and  pulling it out is prolonged, there is a possibility of hypoxia.  So monitor oximetry closely and use high oxygen concen-  trations immediately before and after the placement of the  submental tube (Video 7.2).   The ETT may dislodge intra-operatively as the airway is  shared between the surgeon and anaesthetist; hence, special  attention should be paid to securing the ETT. Preformed nasal  RAE tubes, if used, should be supported on the nasal bridge  and forehead with the help of preformed supports or pads and  secured on the forehead with tapes in addition to securing at  the nostril (Fig. 7.13). Submental tubes can be secured with  sutures (Fig. 7.14) South Pole oral RAE tubes are usually  fixed in the middle of the lower jaw with tapes (Fig. 7.15).    Preferably taped with transparent dressing or specialized eye  pads to capture moisture and prevent drying especially dur-  ing prolonged surgeries (Fig. 7.15).    Reverse Trendelenburg (anti-gravity) position with shoulder  roll for adequate surgical exposure is preferred. Further, the  operation table may be turned away from the anaesthetist  and the anaesthesia machine by 90° or 180°. Hence, long  breathing circuits, [V extensions and long cables for moni-  toring will be required.    Saline-soaked throat packs will be required to protect the air-  way from blood, debris and saliva. It is advised to fix the tail  end of the throat pack to the oral endotracheal tube whenever  feasible to prevent accidental leaving behind of the throat  pack at the end of surgery. Time of insertion and removal of  the throat pack should be documented and carefully checked  before extubation. If interdental wiring is planned at the end  of surgery, then prior to doing so all throat packs should be  removed and gauze counts should be confirmed.   Once the airway is secured, anaesthesia can be maintained  with total intravenous anaesthesia (TIVA) or with volatile  anaesthetics or combination of both as described earlier.  Controlled ventilation with an intermediate-acting muscle  relaxant such as atracurium or vecuronium is used.    Intra-operative analgesia is preferably provided with  short-acting opioids such as fentanyl. Dexamethasone can be  administered intra-operatively to reduce post-operative  swelling, for its analgesic properties and as a prophylactic  against post-operative nausea and vomiting (PONV) [14].  Orthognathic surgeries are associated with a high incidence  of PONV; hence, additional antiemetics such as ondansetron  should be administered prior to extubation especially if inter-  dental wires are planned. Hypothermia can be a potential  complication of prolonged orthognathic surgeries. Hence,  temperature should be monitored and warming measures  like intra-operative warm I.V fluids, forced air mattresses  should be used. If there is a fear of airway compromise post-  extubation, a tracheostomy should be done electively.    Cancer patients and patients undergoing long surgery are at  risk of developing thromboembolic complications. One or  more of the following methods may be used to reduce its  incidence.   Pharmacological—Low-molecular-weight heparin such  as Clexane could be used in patients at high risk for venous  thromboembolism (VTE).    The head and neck region receives rich blood supply from the  branches of the carotid artery, and hence there is a tendency to  bleed profusely during maxillofacial surgeries. Major bleeding  can occur from branches of the maxillary artery or from ptery-  goid venous plexuses, leading to significant blood loss, warrant-  ing blood transfusion. Further, some of these procedures  especially corrective osteotomies are extensive and time con-  suming. Surgical haemostasis is hampered by limited access.  Risks involved in allogeneic blood transfusion have also been  well documented and hence it is important to institute measures  to reduce intra-operative blood loss and blood transfusion.    Methods to control intra-operative blood loss include:  Reverse Trendelenburg (anti-gravity) positioning.    1&2. Positioning and venous drainage: Reverse  Trendelenburg (anti-gravity) positioning by 30° is recom-  mended as it decreases bleeding by causing mild postural  hypotension. Neck should be preferably positioned in the  neutral position or turned slightly towards the surgeon.  Extreme flexion or rotation of the neck to one side should  be avoided to prevent venous engorgement. A minimum  of 2-finger breadth space is recommended between chin  and chest if flexion of neck is required.   3. Antifibrinolytics: A number of clinical trials have shown  that the use of antifibrinolytics like tranexamic acid  (TXA) reduces the peri-operative blood loss and the need  for blood transfusion significantly. In 2011 World Health  Organization added tranexamic acid (TXA) to its list of  essential drugs [15]. The European guidelines on man-  agement of major bleeding and coagulopathy following  trauma suggests a 1A recommendation for the use of  TXA in the case of traumatic and perioperative bleeding  [16]. Dose reduction is required in renal impairment.  Also, caution should be exercised while administering to  patients with history of seizures.   4. Infiltration of the tissues with lignocaine + adrenaline:  Usually the surgeons infiltrate the tissues with ligno-  caine, a local anaesthetic (LA), and adrenaline, a vaso-  constrictor, prior to incision so as to reduce bleeding.  Before doing so, the maximum allowable dose of local  anaesthetic and adrenaline must be calculated and not  exceeded to avoid toxicity and arrhythmias. A dilution of  1:200000 adrenaline is considered safe. If a local anaes-  thetic drug has been used for securing the airway, the  dose of LA used must be considered in total calculation.  ECG should always be monitored during and after  infiltration.   5. Controlled hypotension: is defined as iatrogenic revers-  ible reduction of the patients mean arterial blood pres-  sure. Controlled hypotension can be achieved either by  decreasing peripheral vascular resistance and/or cardiac  output [17]. However, hypotension induced by decreas-  ing cardiac output may not be ideal as it decreases tis-  sue perfusion. A reduction by 30% from the baseline  mean arterial pressure (MAP) level is generally consid-  ered to be safe. But it may be unsafe in some patients  such as those with chronic kidney disease, ischemic  heart disease and carotid artery disease [17]. Therefore,  their suitability for controlled hypotension should be  assessed and recorded during the pre-anaesthetic  workup.    Over the years, several protocols have been developed.  The main strategies are    e Standard anaesthesia with non-pharmacological measures.  ¢ Deep anaesthesia with analgesia.  e Standard anaesthesia with hypotensive drugs.    Pharmacological measures: It relies on drugs used to  either deepen the plane of anaesthesia and/or produce  vasodilatation.   The ideal drug used for controlled hypotension should be  easy to administer, quick in onset and recovery with predict-  able effect, no toxic metabolites and should preserve organ  perfusion [17]. At present, no such drug is available and  hence a combination of drugs is often used.   Deep anaesthesia can be achieved either with volatile  anaesthetics or with intravenous agents.   Most volatile anaesthetic agents are potent vasodilators.  This property can be exploited to reduce blood pressure.  However, when used alone, the minimum alveolar concen-  tration (MAC) values required to achieve this are high and  can result in hepatic and renal injury and also delay awaken-  ing. They are therefore used at lower concentrations with  other pharmacological agents. Most commonly used volatile  agents include isoflurane, sevoflurane and desflurane.  Halothane is preferably avoided due to its arrhythmogenic  potential with adrenaline.    Propofol Infusions: This has been extensively used in neuro  anaesthesia for controlled hypotension as part of total intra-  venous anaesthesia (TIVA). It can be used either as part of  TIVA or combined with volatile anaesthetics.    Opioids: Opioids decrease the doses of agents required to  produce anaesthesia and hypotension by decreasing pain.  Most commonly used short-acting opioids include fentanyl  and remifentanil.    7.7.2.1 Hypotensive Drugs: (Appendix II)  Hypotension should be carried out only to that level needed  to reduce bleeding and only for that time of the surgery  where it is of benefit in reducing significant blood loss. A  number of drugs have been tried either alone or in combina-  tion to reduce blood pressure. While using them, one needs  to be aware of their potential complications and contraindi-  cations. Drugs commonly used are beta-blockers, glyceryl  trinitrate and sodium nitroprusside. Newer drugs like dexme-  detomidine along with a propofol/remifentanil combination  are gaining popularity [18, 19].   Invasive arterial blood pressure monitoring is recom-  mended if infusions of hypotensive drugs are used for con-  trolled hypotension. Intra-op serial monitoring of ABG  (arterial blood gases), acid—base balance and lactate levels    Intra-operative bleeding:  Occurs due to high vascularity of the area not  amenable to cauterization.    with hourly urine-output measurement should help to pre-  vent organ dysfunction.   Tsovolaemic haemodilution was once considered an  adjunct in orthognathic surgeries to induce hypotension to  reduce blood transfusion. It has become less common these  days. The technique involves preoperative blood donation  with IV fluids replacement of circulating volume followed  by autologous whole blood transfusion as needed in the  intra- or post-operative period.   Intra-op Analgesia can be achieved with NSAIDs,  Paracetamol, opioids, intraoral LA infiltration and by mandibular  or maxillary nerve blocks performed intra-op by the surgeon.   Intra-operative complications: The anaesthetist must be  aware of and prepared for potential intra-operative complica-  tions [20, 21] (Table 7.6).    e Airway obstruction above the glottis - consider tracheos-  tomy under LA.   e After extubation, Known or anticipated presence of an  obstructed airway.    e After discussion with the surgeon, the decision of extuba-  tion post-surgery should be taken on a case-by-case basis.   ¢ Before completion of the surgery, the induced hypoten-  sion should be ceased and time should be given to the  surgeon to check for haemostasis. To check haemostasis,  few surgeons prefer to increase mean blood pressure by  20-30% above pre-op level.   e Atthe end of the surgery, throat packs should be removed and  clots or debris should be suctioned from the oropharynx.   e Prior to extubation cuff leak test may be performed to  check for no airway oedema.   ¢ A smooth emergence and extubation with less coughing  and bucking is desirable. With the risk of the possibility of  ongoing bleeding in the upper airway it is usual for  patients to be extubated awake. Confirm that the patient is  awake and breathing spontaneously.   e The Endotracheal tube should be left in situ, until the  patient is fully conscious when the jaws are wired  together, or any other airway obstruction is anticipated.  Two types of maxillomandibular fixation (MMF) are  available: Rigid MMF with jaw wiring, i.e. patients would  be extubated with no ability to open their mouths and    MMF with elastics often applied, albeit later (from hours  to 1 or 2 days) into the recovery phase where mouth open-  ing will not be a problem.   Guedel’s airway or nasopharyngeal tube should be used  to maintain the airway if jaws are not immobilized. A  nasopharyngeal tube provides an extra dimension of  safety in recovery.   Nasal Endotracheal tubes removal should be gentle. To  avoid passing of fresh tube through the vulnerable nasal  mucosa, the ETT can be withdrawn into and left in oro-  pharynx to serve as a nasopharyngeal airway. Submental  ETT should be removed back from the oral cavity and  closure of the submental incision done before the  extubation.   Consider extubation over a tube changer in case of diffi-  cult intubation or surgery.   Avoid applying tight facemask to protect surgical correc-  tion after extubation.   For reintubation, airway equipment / difficult airway  chart should be available on standby and in case of failed  extubation appropriate anaesthetic drugs drawn up in the  required doses.   In case of MME, wire cutters or scissors should be  available immediately for release of elastics band  fixation.   Until successful extubation and stabilization of patient,  the surgical team should remain in the operating  theatre.   Before transfer to recovery, a short period of observation  in the theatre should be followed.   Handover and transfer to recovery should be done by the  anaesthetist.   Careful documentation of surgery details, vital signs, sta-  tus at transfer, blood loss and replacement, drugs given,  analgesia planned and expected problems should be  done.    e Patient should be awake and moving all 4 limbs  e Respiration should be regular with adequate depth  e Stable vital parameters  — SpO2 > 95% on room air  — Pulse rate optimum for age  — Respiratory rate < 30/min  — Normothermic  e No active bleeding from surgical site   — Type of anaesthesia and drugs (time and dose) given,  including analgesics.   In cases of Le Fort I and III fractures, one should be aware   that the degree of oedema could worsen in the first 48 h.   to a high dependency unit. Patients sent to ICU are those    ICU, the patient may be required to be sent to another hospi-  tal (see appendix III and 1V).    4Ds 3 Ss  Difficult mask ventilation Surgical cause for airway compromise**  Difficult intubation/reintubation Suspected airway oedema  Delayed recovery Suspected airway collapse  Difficulty because of pre-existing disease    Extubate In suspected airway  over collapse, attempt  AEC/FOB to extubate under  in deep inhalational  OT/ICU/HDU anaesthesia with  patient breathing    This flow chart should be used in conjunction with the text  * Exchange should be performed only if the patient did not have difficult mask    Airway obstruction persists  ventilation, difficult intubation and is not a case of full stomach (obese, pregnant,    Reintubate  recent ingestion of food or raised intra-abdominal pressure)  ** Suspected nerve damage/structural damage to airway  AEC = Airway exchange catheter Tracheostomy   In the post-anaesthesia care unit (PACU) the close monitor-  ing of complications should be done, which can lead to air-  way obstruction such as soft-tissue swelling and formation  of haematoma. Capnography may provide an earlier warning  of serious problems than pulse oximetry when supplemental  oxygen is being administered. Even in uncomplicated cases,  the effects of residual anaesthetic agents on airway physiol-  ogy are more pronounced in patients with MMF who may  experience increased resistance to breathing.    Haematoma formation in the early postoperative period is  an uncommon but potentially airway-threatening complica-  tion of some maxillofacial operations, notably neck surgery,  thyroid resections and floor of mouth surgery. The rate at  which airway compromise occurs is variable. Emergency  decompression of the haematoma may be even done at the  bedside. It involves removing the clips/sutures and manu-  ally evacuating the haematoma with a Yankaur sucker.  However, this may not alleviate the airway obstruction ade-  quately due to oedema that results from venous congestion.  The airway needs to be secured urgently. The method of  securing the airway should take into consideration informa-  tion from the initial operation, but it is expected to be more  challenging and may require expert airway management.    Factors that predispose to PONV include the female gender, a  history of motion sickness, a low threshold for nausea, preop-  erative anxiety, obesity and gastric distension. Volatile anaes-  thetic agents, nitrous oxide, opioid usage and intubation have  also been implicated as has prolonged surgery, early oral intake  and certain types of surgery, including maxillofacial surgery.   Vomiting in patients with MMF is dangerous as it may pre-  dispose to aspiration. If the jaws are wired together, there must  be wire cutters immediately available, which accompany the  patient from theatre, to the PACU, and also to the ward.   PONV prophylaxis is best given round the clock for the  first 24 h and longer if opioids continue to be used. If treat-  ment for PONV is required within 6 h of PONV prophylaxis,  it should ideally be with a different class of anti-emetic drug  to that used initially (See Appendix I).    After orthognathic surgery immediate postoperative pain is  often not severe, and this is contributed to by the generous    intra-operative use of local anaesthesia. A multi-modal anal-  gesia approach should also be utilized perioperatively by  combining opioids with paracetamol and non-steroidal anti-  inflammatory drugs towards the end of the case.   Patient Control Analgesia (PCA): It allows the patient to  self-administer intravenous analgesics by means of a com-  puter-controlled pump. It administers the pre-programmed  dose on demand by the individual.    2. What are the important features to look for during the  pre- anaesthetic/presurgical evaluation?   ¢ Look for associated syndromes the most common of  which are Pierre Robin Sequence, Treacher Collins syn-  drome and Down syndrome.   e Chest x-ray if repeated chest infections or respiratory  signs present on clinical examination    ¢ Meet the parents, allay their anxiety and give full explana-  tion of procedure.   e Solids and milk feeds 6 h prior to surgery and clear fluids,  especially with glucose/sugar, 2 h prior to surgery    3. What preparations are necessary on day of surgery?  Preparation: On day of surgery   ¢ Check Equipment and Drugs: Suction, Oxygen, Airway,  Pharmacy (the pneumonic SOAP helps)   e Ensure that the difficult airway cart with rescue devices is  available    Monitors: ECG, NIBP, Pulse Oximeter, EtCOs;, and air-  way pressure (once intubated)    4. What are the problems that can present during anaesthesia?  ¢ Induction—intravenous or inhalational?  ¢ Mask ventilation may be difficult especially in cases of  facial cleft  e Laryngoscopy. The larynx is anterior, the tongue rela-  tively large and laryngoscope tends to slip into the cleft  ¢ Position of the patient in this case the trunk of the baby  should be supported on a large pillow with the neck  hyperextended and head stabilized within a head ring.  e Sharing the airway with the surgeon  — kinking of tube when the gag is placed  — accidental extubation during positioning of the baby or  removal of the gag  — tube may be pushed endobronchially resulting in one  lung ventilation when gag is applied  — throat pack/other packs may be left behind after sur-  gery causing airway obstruction   e Access to the patient difficult, so make sure that intrave-  nous access is good and fixed well before draping   e Analgesics like paracetamol and short-acting opioids like  fentanyl may be used.   e Extubation is often more difficult than intubation. If there is  any query regarding obstruction to the airway, place a naso-  pharyngeal airway and a tongue stitch prior to extubation.    5. Could there be any problems post operatively? If so enu-  merate them.   ¢ Laryngospasm or post extubation stridor due to oedema  of the upper airway: Treat with CPAP, humidified oxygen,  aerosolized adrenaline, intravenous dexamethasone and  nebulized steroids.   e Seizures/Anticonvulsants: Rule out hyperthermia (tepid  sponging and paracetamol) and hyponatraemia (intrave-  nous normal saline).    A 27-year-old male presented with the history of polytrauma  following a road traffic accident. He gives a history of brief  period of loss of consciousness following injury. No history of  seizures, or other comorbidities. On examination, his GCS  was 15/15, and he was haemodynamically stable. Airway  examination revealed restricted mouth opening of just one fin-  ger breadth, a short neck and a lacerated wound on the lower  lip and chin with emphysema on the left side of the face  extending into submandibular region. Cardiovascular, respira-  tory, abdominal and central nervous system examination was  unremarkable. Blood investigations revealed increased CPK.   CT brain and spine showed a 3.5-mm extra-dural haemor-  rhage in the right temporal region, right frontal haemorrhagic  contusion, an undisplaced fracture of the body of the man-  dible in bilateral parasymphyseal region with a displaced  right zygomatic arch, a comminuted, mildly displaced frac-  ture of right squamous temporal bone and undisplaced frac-  ture of superior facet of C5 vertebra (Fig. 7.16).    Fig. 7.16 Photograph of a patient with polytrauma & facial injuries    1. Following things are true about blunt trauma to face  EXCEPT  a. Cervical spine injury occurs in up to 10% of cases  b. Drugs and alcohol could be a contributing factor  c. Potential for injuries to other organs & massive blood  loss  d. Injuries in children are less severe than in adults  Answer: d) Injuries in children are usually more severe than  in adults  2. In this patient, following could be cause of restricted  mouth opening EXCEPT:  a. Fracture Mandible  b. Presence of trismus  c. Cervical collar  d. # of superior facet of C5 vertebra  Answer: d) Fracture of Cervical vertebra usually does not  restrict mouth opening  3. What is the reason for the presence of subcutaneous  emphysema of the face in this patient?  a. Pneumothorax  b. Tracheal injury  c. Soft-tissue injury  d. # involving sinuses  Answer: d) Fractures involving air-filled sinuses around face  can cause subcutaneous emphysema    4. What is the EXCEPTION to the bedside predictors of  difficult intubation in a case like this?  a. Receding mandible  b. Facial injury  c. Edentulous  d. Cervical collar  Answer: c) Absence of teeth usually causes difficulty in ven-  tilation rather than difficulty in intubation  5. Which of the following is most useful for detection of  Extradural haematoma?  a. CT scan of head  b. MRI scan of head  c. X-Ray Skull  d. Careful clinical examination  Answer: a) A CT scan is more appropriate investigation in an  emergency  6. What would be your preferred method for securing the  airway?  a. Conventional laryngoscopy with oral endotracheal  intubation.  b. Conventional laryngoscopy with nasal endotracheal  intubation.  c. Fibre optic bronchoscopy with nasal intubation.   d. Conventional laryngoscopy with manual in line sta-  bilization with nasal endotracheal intubation.  Answer: b) Conventional laryngoscopy with nasal endotra-   cheal intubation  7. What would be your preferred airway device for secur-  ing the airway?  a. Regular endotracheal tube  b. Nasal RAE tube  c. Oral RAE tube  d. Reinforced cuffed endotracheal tube  Answer: b) Nasal RAE tube.  8. What do you anticipate with respect to airway in this  case?  a. Difficult mask ventilation  b. Difficult laryngoscopy  c. Both a) and b)  d. Normal ventilation and laryngoscopy.  Answer: c) Both difficult mask ventilation and laryngoscopy.  9. The following monitoring would be useful during sur-  gery in a case like this EXCEPT:  a. Invasive arterial pressure  b. Urine output  c. Central venous pressure monitoring  d. BIS monitoring  Answer: c) Central venous pressure monitoring would not  add any additional value in a case like this  10. Where would you shift this patient after the surgery?  a. General ward  b. Special ward    c. ICU Answer: d) PCA fentanyl will be an appropriate choice as   d. HDU patient has multiple injuries and is being monitored in  Answer: d). HDU will be an appropriate place to monitor HDU.   11. What is the most suitable method for pain relief in this gery for this patient?    Drug Action/group Dosage  Dexmedetomidine:|! Q-adrenergic-agonists Bolus: 1 mcg/kg over 10 mins followed by continuous infusion of 0.2-  Imegs/kg/h  Atropine Anticholinergic 0.5 mg I. V  Glycopyrrolate Anticholinergic Antisialagogue: 3-4 1/kg I. M 30-60 min prior.  Bradycardia: 0.1 mg I.V repeated every 2 to 3 mins.  Topical Lignocaine Local anaesthetic Maximum safe dose: Adults: 9-10 mg/kg lean body weight.  Paediatrics: 4.5 mg/kg  Dexamethasone Adrenocortical steroid:  Anti-inflammatory dose 0.1-0.2 mg/ kg  Antiemetic [14] 4-5 mg L.V  Ondansetron Antiemetic—Serotonin antagonist _0.1—0.2 mg/kg  Prochlorperazine Antiemetic—Dopamine receptor 0.25 mg/kg  (Stemetil) antagonist  Tranexamic acid [15] Antifibrinolytic 1. Bolus dose: 15 mg/kg can be repeated every 6-8 h (prior to incision) or    2. Continuous infusion during the surgery: 1 g over 10 mins followed by 1  gm over 8 h or 20-25 mg/kg followed by 1—2 mg/kg/h).   Non-selective: Boluses: 0.25 mg/kg followed by infusion: Vasodilatation + heart rate control Bronchospasm   by infusion of 0.3—1 mcg/kg/hr. Analgesic properties  Magnesium sulphate Bolus: 20-60 mg/kg Vasodilatation with heart rate control. Prolonged neuromuscular    HR: /min BP: mm Hg RR:  SpO2: % O2: min AVPU score:  Airway: Intubated and assisted / Intubated and spontaneous / Not  intubated  Patent IV access:  Fluid on flow:    The transfer of the patient to a Centre where intensive care is  available may sometimes be required if the facilities at the  current hospital are inadequate. Most of these patients are  critically ill and need the utmost care and planning to ensure  safety during transfer. It is the responsibility of the referring  team (surgeon as well as anaesthesiologist) to ensure a safe  handover to the new treating team of doctors.   The following guidelines may be used to develop local  protocols for inter-hospital transfer.    e The decision to transfer should be done by the treating  team of doctors.   e The patient’s family should be counselled by the treating  doctor for the reason of transfer.   ¢ Obtain consent from the patient’s family after explaining  the need as well as the risks involved in transfer.   e The administrative coordination between the two hospi-  tals, e.g. checking the availability of beds, required doc-  tors, equipment, etc. should be performed telephonically.  The verbal consent to accept the patient by the destination  hospital authorities should be done and documented.   e A short summary of the patient’s clinical condition and  handover document should be prepared.   e The transfer team should be identified. It should comprise  at least 2 members who are adequately trained in handling  sick patients, e.g. while transferring an intubated patient,  the team should be trained in managing intubated patients.  At least one doctor (preferably an anaesthetist) should  accompany/supervise the patient during transfer especially  sick patients.   ¢ Clinical stability of the patient should be confirmed  before shifting.   e Patient should be stabilised before transfer. The following  should be confirmed just before transfer—a patent IV  line, a patent airway access, a functioning monitor with    adequate battery backup. In case of an intubated  patient -DO NOT EXTUBATE just prior to transfer.  Note and record vital signs just before transfer.   During transfer the vitals should be monitored continu-  ously and documented frequently.   Anticipation of problems during transfer and prepared-  ness will help ensure safe transfer.   Upon reaching the destination hospital, the transferring  team should ensure that the patient is safely shifted to the  desired critical care area and the hand-over formalities  completed.    . Shaw I, Kumar C, Dodds C, editors. Oxford textbook of Anaesthesia    for Oral and maxillofacial surgery. Oxford, UK: Oxford University  Press; 2010.    . Sherwood MW, Douketis JD, Patel MR, Piccini JP, Hellkamp AS,    Lokhnygina Y, et al. Outcomes of temporary interruption of rivar-  oxaban compared with warfarin in patients with nonvalvular atrial  fibrillation: results from the rivaroxaban once daily, oral, direct fac-  tor Xa inhibition compared with vitamin K antagonism for preven-  tion of stroke and embolism trial in atrial fibrillation (ROCKET  AF). Circulation. 2014;129(18):1850-9.    trauma life support for doctors. 6th ed. Chicago: American College  of Surgeons; 1997.    airway. In: Jacob R, editor. Understanding paediatric anaesthesia.  3rd ed. 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The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in    a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.   e To identify the strategies in building an effective working  relationship with the imaging department and help plan  appropriate imaging investigations.   ¢ To understand the principles of various imaging tech-  niques; the advantages and disadvantages of these tech-  niques in varying clinical scenarios.   e To gain awareness about the benefits and risks of using  ionizing radiation and understand the basic principles of  radiation protection.   ¢ To establish the role of imaging as a treatment guide fol-  lowing different maxillofacial surgeries.   Accurate diagnosis is the mainstay of proper surgical man-  agement in a maxillofacial surgical patient. Definitive diag-  nosis may be possible in a few patients based on clinical  evaluation in the outpatient department or emergency setup.  Other cases may require the use of supplementary investiga-  tions, including radiological imaging.   Like other medical specialties, the scope of Radiology is  vast, playing a significant role in disease management.  Penning a chapter on Radiology for a clinical branch-like  Maxillofacial surgery is an uphill task. As a clinician, the  maxillofacial surgeon, after having made the diagnosis, has  the desire to visualize and gain in-depth knowledge of the  ongoing disease process within the patient. Radiology plays  an important supporting role in helping the clinician visual-  ize within the patient’s body. It is hence necessary for clini-  cians to have basic knowledge of the key concepts of   Department of Radiology, SDM College of Medical Sciences and  Hospital, Shri Dharmasthala Manjunatheshwara University,  Dharwad, India    © The Association of Oral and Maxillofacial Surgeons of India 2021    Radiology, helping them understand its applications in the  diagnosis of a patient’s clinical condition.   The scope of practice of a practicing MFS includes both  surgical and nonsurgical problems that affect the orofacial  region, and hence they need to be well versed with the imag-  ing concepts of the head and neck region.   Anatomy of the head and neck is complex and imaging in  this region poses several challenges and an MFS needs to be  cognizant of them.   ¢ Define the anatomy pertinent to the region of clini-  cal interest.   ¢ Define the critical relation to vital structures like the  brain and cerebral vessels.    Conventional Radiography is one of the modalities that  have been available from early days, ever since X-rays were  discovered by Wilhelm Conrad Roentgen in 1895. However,  it is regarded as a poor choice for anatomical evaluation due  to overlapping of anatomical structures especially in the  head and neck region. Yet it still has a popular role in its own  humble way. It is universally available, the least time-  consuming imaging investigation, and gives a ‘bird’s eye  view’ of the region of interest. It provides instant practical    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1-15-1346-6_8    information on the status of the airway and osseous ele-  ments, helps inferring the underlying pathological process  based on the presence of air pockets or bony destruction, and  at times may even reflect systemic pathology. It guides the  clinician as to the further steps to be taken for patient man-  agement or to the need for further imaging. Despite it being  the era of advanced technology, conventional radiography  should invariably be the first choice among imaging investi-  gations. In cases of complex maxillofacial injuries and poly-  trauma, when the patient’s clinical status demands the next  level of investigation, CT may be performed first, bypassing  conventional radiography.   Pioneers in the field of imaging had a yearning to develop  modalities that could demonstrate finer anatomical details in  the region of interest.    This, coupled with the technological evolution, has  paved the way for the development of various radio-  logical imaging technologies that include:    These advances in imaging techniques have enabled the  MFS to diagnose with greater confidence and refine their  approach to surgical treatment. This has also led to a reduc-  tion in unexpected surprises springing up on the surgical  table.   Considering that a range of imaging modalities are avail-  able, it is imperative that the MFS has basic knowledge about  their functionality, being familiar with the advantages and  disadvantages of each so that the appropriate imaging inves-  tigation that gives the most optimal information in a given  clinical setup can be selected. The rationale behind choosing  the right investigation is that it should be easily available,  least time consuming, cause least possible discomfort to the  patient and be economical. Appropriate use of the concerned  imaging modality should provide the maximum possible  anatomical and functional information. This is possible if a  genuine effort is made by an MFS to understand the basic  principles and other related components of specific diagnos-  tic imaging relevant to his field of interest and establish a  close rapport with the imaging department.    8.2. Requesting an Imaging Investigation  Prior to requesting a radiological investigation, the MFS  needs to have a clear idea about the usefulness of an investi-  gation, its limitations, and whether it will help to improve the  patient outcome. A radiological imaging requisition must  specify the choice of investigation and the surgeon’s expec-  tations from it, so that the information received strengthens  his approach in treating the patient.   It must provide mandatory demographic and relevant  clinical data, including the patient’s symptoms, which pri-  marily brought him to the MFS, their duration, clinical signs,  and the clinician’s differential diagnosis of the same. In addi-  tion to concentrating on the clinical data, entries made avail-  able through the Hospital Information system (HIS) and the  Radiology Information system (RIS), accurate patient identi-  fication by the MFS is essential prior to referral to the imag-  ing department.    An MFS deals with patients suffering from maxillofacial  disease processes, but being a clinician primarily he is  expected to have basic knowledge of various systemic clini-  cal problems as well. Systemic disease may manifest as dis-  ease in the maxillofacial region or vice versa. For instance,  a cystic lesion in the jaw could be the primary radiographic  finding in a patient suffering from hyperparathyroidism.  Similarly, patients suffering from systemic diseases like  osteopetrosis, fluorosis, fibrous dysplasia, and other marrow  infiltrative disorders could also present with a disease in the  maxillofacial region. Further, detection of congenital anom-  alies in the maxillofacial region is an indication for a more  detailed survey to rule out associated anomalies elsewhere.  The surgeon should be able to identify radiological images,  correlate the same with the report and the patient’s clinical  status, and focus on timely decision making and patient man-  agement, thus optimizing the patient’s outcome. However, in a  dire emergency when a radiologist’s opinion is not available,  or a delay is expected in obtaining the same, an MFS should  be able to interpret radiographs that suggest life-threatening  conditions like tension pneumothorax, aspiration broncho-  pneumonia, foreign body aspiration, or pulmonary edema  among others. Imaging can help the MFS in narrowing down  on the clinical diagnosis, in staging and evaluating the progno-  sis of a disease process, or in surgical planning by depicting  the exact extent of a lesion after diagnosis is confirmed.  MEFS’ need to communicate with their radiology coun-  terparts the expectations they have from imaging of a case  so that the radiologist can provide the relevant anatomical    and functional information from the region of interest.  Each imaging modality has its own reporting language  and the surgeon needs to be well versed with the language  used and have a clear concept of principles of image for-  mation, specific to the energy source used in the particular  investigation.    The responsibility of the imaging department is conducting  the specified diagnostic imaging investigation, interpretation  of the tests or procedures by the radiologist and providing the  clinician with accurate reports of the performed investigation  as early as possible. Clinical radiologists function as key  members of multidisciplinary teams, being an integral part  of patient care.    Different types of energies are used in diagnostic imaging.  These energies are imperceptible to the human eye and when  they are passed to the desired location in the body, they inter-  act with the body tissues in different ways. The tissue inter-  actions can reveal information about the tissue, but they need  to be interpreted. Access to this information is possible only  if it is converted into a visible form on a display system. In  essence, the requirements for an imaging investigation are; a  reliable and reproducible energy form, a subject (the patient)  into whom the energy can be sent, and a format that can con-  vert the invisible image into a visible display.   X-rays and gamma rays are photon energies and members  of the electromagnetic spectrum having a wide range of  wavelengths and frequencies. X-rays have very small wave-  lengths being lesser than 1 A unit and greater than 0.1 A units.  This range of specific frequencies and wavelengths of X-rays  give them special properties, gaining popularity in diagnos-  tic imaging.   Gamma rays have shorter wavelengths and higher fre-  quencies than X rays. They are used in nuclear medicine  both for diagnostic and therapeutic purposes.   Conventional radiography, including mammography, flu-  oroscopy, computed tomography (CT), is a modality that  generates images of the ionizing radiation. It works on the  same basic principle, which essentially involves passing of  an X-ray beam through the body followed by absorption and  scattering of a portion of the X-ray energy by the body tis-  sues and transmission of the resultant radiographic pattern  formed by differential tissue absorption to a detector for  recording or further computer processing.    The popularity of X-rays as an imaging modality is due to  its optimum penetration power and photochemical and fluores-  cent properties. Its fluorescent property is useful in converting  invisible images into visible light images, while the photo-  chemical property is responsible for conversion of the visible  light image into a permanent visible record called radiograph.   Conventional radiography includes plain radiographs of  different body parts like chest, skull, PNS, etc., contrast stud-  ies of the gastrointestinal tract like Barium studies, contrast  studies of the genitourinary tract like Intravenous urography  (IVU), and contrast studies of the vascular system like  Arteriography, Phlebography, etc.   Fluoroscopy involves a continuous display of real-time  movements of moving structures as radiographic images on  the monitor, e.g., act of swallowing, movement of the soft  palate, movement of the temporomandibular joint, cardiac  pulsations, diaphragmatic movements, etc.   Computed Tomography includes cross-sectional imaging  with its modifications like 3D, Volume rendering, Multiplanar  reconstruction images, C.T. angiography, etc.   Ultrasound imaging or sonography makes use of high-  frequency sound waves that are transmitted from the trans-  ducer into the body. The reflection of these waves off the  body structures forms the basis of ultrasound image forma-  tion. The information necessary for image production is pro-  vided by the amplitude of the reflected sound signal and the  time taken for it to travel through the body. Commonly ultra-  sound is used in the imaging of the abdomen, fetus, breast,  eye, heart, vessels, and the musculoskeletal system. In recent  years, there has been much research into ultrasound of the  maxillofacial region, and it has been found to have a range of  unique applications, including the evaluation of cervical  lymph nodes and the detection of space infections and cystic  and solid lesions of the head and neck. In early cases of  peripherally located carcinoma of the tongue, ultrasonogra-  phy may be an initial mode of imaging for evaluation.   Ultrasound imaging is not associated with the same risks  as ionizing radiation and is considered to be generally safe if  used appropriately. Ultrasound energy does have the potential  to produce biological effects on the body and can cause mini-  mal heating of tissues and in certain cases produce tiny gas  pockets in the tissues and body fluids known as cavitation.   Magnetic resonance imaging makes use of strong mag-  netic fields and radiofrequency energy to create images. The  signals that produce an MR image originate from the protons  present in water and fat molecules in the body. Application  of a strong magnetic field by the MRI scanner causes the  protons within the body to align themselves. Radiofrequency  current is then passed into the patient’s body creating a vary-  ing magnetic field that causes the protons to flip their spins.  Turning off the radiofrequency pulse causes the protons to  return to their normal spins, producing radio signals that are  measured by receivers in the scanner and used to make digi-  tal images of the scanned area of the body.    Many forms of MRI exist, diffusion and functional MRI  being the most common. Diffusion MRI helps in diagnosing  disease processes like stroke that restricts diffusion of water  molecules across body tissues, while functional MRI is used  to visualize the functional activity of the brain. MRI does not  use ionizing radiation but since it uses strong magnets, any  form of metal implants like artificial joints and heart valves,  pacemakers, cochlear implants, metal plates, screws, and  rods do pose a hazard.   Thermography makes use of specialized cameras that can  detect electromagnetic light energy in infrared wavelengths.  Medical thermography produces a topographic heat map,  displayed in the form of various color shades, based on the  differential skin temperature at various dermatomes bearing  resemblance to the visible image of the body. It is not a  structural imaging technology providing information on  structural changes like other modalities and does not provide  a diagnosis, rather only aids in reaching a diagnosis. It is  completely safe and painless, does not make use of any form  of radiation, and is a unique form of imaging in that it can  document pain, thus helping to differentiate malingering  from an organic cause for the pain.    Plain radiographic film interpretation is an essential skill.  The current implementation of electronic health records and  digitization of the health care system has made radiographic  images available throughout the hospital and an MFS may  often have to interpret medical images. So, it is important  that they know the basics of medical image interpretation,  and this knowledge may prove to be crucial in an acute clini-  cal setting. They should be aware of tissue appearances on  radiographs and be capable of making a basic distinction  between normal and abnormal.   Understanding the concept of density and contrast is fun-  damental to interpreting an X-ray image (radiographic  image). Different body tissues, including bone, soft tissues,  fat, and air, all attenuate the X-ray beam differently.  Differential absorption of X-ray photons by the body tissues  results in variable energy values of emerging photons pro-  ducing an invisible image, which is converted into visible  form as areas of different gray scales. The contrast on the  image is the difference between adjacent densities. These  densities range from white to black with varying gray shades  in between them. If the densities of two tissues adjacent to  each other are greatly different (say a white and a black den-  sity tissue), then they are said to have high contrast. If the  densities of two tissues adjacent to each other are similar,    then they are said to have low contrast. They appear similar  in color, differing in their shades of gray. When two body  structures of identical density are exactly side by side, the  line of demarcation cannot be made out and whole of it  appears as one structure.   Consider a chest radiograph. What do you think is the  whitest component seen on the radiograph? Most commonly  the answers given are heart, bones, below the diaphragm, and  so on. Rarely does anyone mention that the “R” marker is the  whitest. Similarly, if asked which the darkest component is,  the popular answer given is, the lung surrounding the heart,  very rarely does one mention that the air surrounding the  chest is the darkest. Analyzing as to why the “R” marker is  white and the air surrounding is dark, the reasoning is that  the chest radiograph is nothing but a representation of the  tissues in that region in various gray scales between extreme  white and extreme dark, depending upon the variable absorp-  tion of X-ray photons in their path through the tissues.   The opacity produced on a radiograph by a specific body  tissue is a representation of the actual penetrative ability of  X-rays to pass through that tissue and then be incident on the  film. Air and fat absorb less radiation, allowing more X-rays  to pass through and be incident on the radiograph making  their images appear black and pale gray, respectively. Bone  and metal as is the “R” marker made of lead absorbs more  radiation and so fewer X-rays are incident on the film mak-  ing them appear white.   Continuing with the example of chest radiograph, what  are branching structures that are seen in the lung fields? Are  they arteries, veins, bronchi, lymphatics, or a combination of  all these? The common answer given is bronchovascular.  The correct answer is arteries and their branches, but not the  bronchial tree. The explanation is simple. Air in the bronchi  is surrounded by air in the alveoli and so no contrast exists  between them and they are hence not seen. On the other  hand, blood in the arteries is surrounded by air in the alveoli  and hence they stand out. Veins do contain blood but are too  less in number and do not significantly contribute to the  branching structures. Lymphatics are too small to be detected.   If this basis of X-ray image formation is understood, you  can easily interpret any radiographic image provided you  have sound knowledge of the relevant anatomy, pathology,  and pathophysiology.    Electromagnetic radiation has a wide range of wavelengths  ranging from being smaller than angstrom units to as large    as many miles. Smaller wavelengths have greater energy  and penetration power and are called photon energy mean-  ing packets of energy and not particle energy. The two ener-  gies that are of concern in the present context are X-rays  and Gamma rays. Passage of these energies through body  tissues either for diagnostic or therapeutic purposes results  in a series of events beginning with an incidence of the  X-ray photon into tissue followed by sequential changes at  molecular and atomic levels. The transformation of energy  from the photon results in ionization, namely, in the dis-  charge of an electron and a free radical. Hence, such ener-  gies are called ionizing radiation and the process involves  breakage of enzyme bonds and formation of new molecules  manifesting in the form of various repairable and irrepara-  ble biological effects.   The concept of photon energy and its effect on body tis-  sues can be explained using the following example. Consider  a hot iron ball being passed through a pile of corn (Fig. 8.1).  The temperature of the ball after exiting the corn pile is  grossly reduced. It is because the ball, during its transit  through the pile, shares the energy with the corn in contact  with it. The corn in very close contact to the ball is burnt to  ashes, the corn a little farther away, is burnt to charcoal, corn  still further away is converted to popcorn, while corn far  away from the ball remains unaffected. The effect on the  corn is directly proportional to the energy transferred from  the hot iron ball to the corn. The same thing happens when  photon energy passes through the body tissues with changes  occurring at atomic level.    8.7.1.1 X-Rays  X-rays are a form of electromagnetic radiation. Man-made  X-rays are produced when fast-moving electrons undergo  sudden deceleration on collision and interaction with the tar-  get anode in an X-ray tube. The electrons are emitted by the  cathode, on being heated up by the electric current flowing  through it.   Though conventional X-ray imaging has evolved over the  past 100 years, the basic principle remains the same. On pas-  sage of an X-ray beam through the body, the beam is attenu-    ated by the body’s internal structures, being partly absorbed  and partly scattered. The remnant of the X-ray energy is  transmitted to a detector that records the image for later eval-  uation. The recording of the radiographic pattern may be on  film or other electronic devices. The image created is due to  weakening of the X-rays by tissues of varying density  encountered along the beam’s travel path. Bone being dense  tissue, absorbs or attenuates a great deal of the X-rays, while  soft tissue being much less dense attenuates or absorbs far  less X-ray energy. These differences in absorption help in  creating images that can clearly show normal tissue appear-  ance as well as different forms of pathology.   Conventional radiography, fluoroscopy, and CT all work  on the same basic principle differing only in their purpose. In  radiography, a single image is recorded for later evaluation,  in fluoroscopy X-ray images are displayed on a monitor in a  continuous flow, thus allowing monitoring of a procedure or  contrast passage in real time and in CT imaging a multitude  of images are recorded as the detector rotates around the  patient’s body followed by reconstruction of the individual  images as cross-sectional images of internal organs and  tissues.   Computerized axial tomography is a computer-controlled  radiological study that produces a reconstructed image of a  cross-sectional slice of the desired section of the body. Its  features include the absence of superimposition, less scatter  and better tissue differentiation of the anatomical slice, thin-  ner slices producing a better reconstructed image. The major  drawback of conventional radiography is the overlapping of  anatomical structures resulting in difficulty in evaluation of  desired structures in a particular plane. The imaging method  “Tomography” was introduced to overcome this drawback  and involves imaging of anatomical structures at the desired  plane with the blurring of overlapping structures. Classical  conventional tomography had its own inherent drawbacks,  which included poor-quality blurred images, high radiation  dosage, and use of complicated techniques which led to it  being replaced by tomography assisted by computer technol-    Fig. 8.1 Illustration of passing a hot iron ball through a pile of corn and its effect on the corn    ogy called ‘Computer assisted Tomography’ (CAT). With a  rise in popularity, CAT has been replaced by the word C.T.  and technological advances have resulted in the development  of better equipment capable of scanning the entire body  within a few seconds. This provides fine anatomical details  of submillimetric structures, allows tracing of blood flow in  all its phases, and also permits clear depiction of information  related to moving structures like the heart in real time as well  as their external and internal morphology. Two types of CT  have been described based on the shape of the X-ray beam,  the traditional fan beam CT and cone beam CT.   e The X-ray tube—a specialized tube of high heat loading  and dissipating capacity with a very small focal spot, as a  source of X-ray energy   e A computer of high capacity that evaluates attenuated  photon energy from detectors, stores the values, and con-  verts these values to sectional images   e A console that manipulates all data stored in the com-  puter, helping in reconstructing the image at desired  planes with volumetric imaging or multiplanar recon-  struction, 3D and volume rendering, followed by projec-  tion of the desired structures based on their density  values, etc.    ¢ A gantry that houses X-ray tubes, detectors, and related  cables with a central aperture for the patient’s body to  enter for sectional imaging   CT scans have many benefits that far outweigh their risk.  It is quick and easy, widely available, and provides superior  anatomic and bone details. It has Volume Rendering  Technique (VRT), Maximum Intensity Projection (MIP), 3D  and Shaded Surface Display (SSD) capabilities, provides  multiplanar reconstruction images in desired planes, and is  the modality of choice for follow-up studies. (Figs. 8.3a, b,  8.4a, b, 8.5a,b, 8.6a, b, 8.7a, b, 8.8a, b, 8.9a, b, 8.10, 8.11,  and 8.12).   The possible risks of using CT imaging include exposure  to ionizing radiation and the predicament of suffering an  allergic reaction due to use of contrast media. One drawback  of CT when compared to MRI is the lesser resolution of soft-  tissue detail. Other disadvantages are the associated cost and  the limitations of its use in the pediatric age group due to the  need of sedation.   Motion and beam-hardening artifacts used to be considered  as major drawbacks, but they have been markedly mini-  mized with advances in technology. A physical limitation is  that the patient needs to weigh less than 300 to 400 lbs. For    Fig.8.2 (a) CT room shows Gantry, Patient couch, Emergency crash trolley, Central suction, and Oxygen and Pressure Injector. (b) Control room  showing a CT technician working with various controls and the image acquisition system    Fig. 8.3. (a) Museum Model of head showing how axial slices are planned. The slice thickness varies from submillimeter to 10 mm, depending  on the ROI (region of interest) and anatomical structure to be seen. (b) Stacked CT slices showing specific anatomy at a specific slice    Fig. 8.4 (a) CT axial primary slice soft-tissue window at the level of | same patient at the level of optic nerve showing anterior, posterior,  optic nerves showing mediolateral and anteroposterior relations and not superior, and inferior relations  supero inferior relations. (b) CT sagittal reconstructed image of the    ig. 8.5 (a) and (b).CT coronal bone window primary images at different levels of paranasal sinuses    Fig. 8.6 (a) and (b).CT coronal soft-tissue window primary images at different levels of Paranasal sinuses    Fig. 8.7 (a) and (b). CT reconstructed coronal images from thicker slices of paranasal sinuses at different levels. (a) bone window. (b) soft-tissue  window. Note: coarse appearance    Fig. 8.8 (a) CT direct slice of T.M. joint in its sagittal plane. Bone window. (b) CT reconstructed image from primary axial thick slices of T.M.  joint in its sagittal plane. Note: coarse appearance    Fig. 8.9 (a) CT 3D reconstructed image for surface bony details from thicker slices. Note: coarse appearance. (b) CT 3D reconstructed image    Fig. 8.10 CT 3D surface rendering reconstructed image for surface  soft-tissue details from thinner slices    CT imaging of the head region, axial and direct coronal  slices are primarily possible, for the neck region, only axial  slices are possible and in the temporomandibular joint  region axial and direct sagittal slices are possible. It is    through the raw data thus available that images are recon-  structed in any desired plane.   Conventional OPG is a first-level diagnostic exam that  provides a gross panoramic view and just enough informa-  tion about alignment of the teeth and any other related gross  pathology. Unavoidable overlapping of some of the anatomi-  cal structures hinders accurate evaluation. To overcome these  drawbacks, Dentascans and CT OPGs are used. They are  extended applications of CT scan and involve the acquisition  of thin axial submillimeter slices of the region covering the  upper and lower jaws (Fig. 8.13). Reconstructed images  obtained using these raw data image slices form the CT OPG  or Dentascan image (Fig. 8.14a, b).   Coronal reconstructed images form the C.T. OPG  (Fig. 8.15a, b, c). It is a second-level imaging technique  wherein evaluation of the osseous elements of the maxilla  and mandible is far better in comparison to conventional  OPG. It provides the MFS with a better understanding of the  morphology of the roots and the degree of contiguity between  the roots and the mandibular canal. The information acquired  is then used in planning and performing minimally invasive  surgical procedures [1].    (a) CT Primary axial slice of neck at midlaryngeal level. (b) and (c) Sagittal and coronal reconstructed images from sequential CT  primary axial slices. (d) CT Volume rendering technique (VRT) image of air column in the pharynx, larynx, and tracheal region as minimum den-  sity projection from primary axial slices (a). Note: Better visualization of laryngocele    Fig. 8.13 CT Scanogram for dentascan showing submillimeter axial  slices planning in the region of maxilla and mandible    Fig.8.12 CT angiogram: 3D VRT (Volume Rendering Technique) dis-  playing carotid arteries and its branches along with carotid body tumor.  It is a reconstructed image from primary thin axial CT slices    Fig. 8.14 (a) and (b) .Reformatted panoramic CT images (b) are procured at desired plane of the jaw by curvilinear graphic lines drawn on the  primary axial slice (a) selected    Fig. 8.15 (a), (b), and (c). a and b show coronal plain image planning of individual tooth. c shows the coronal reformatted image of tooth    Fig. 8.16 (a) and (b). Schematic diagram. (a) shows fan beam of X-rays from X-ray tube with curvilinear row of detectors. (b) shows cone beam   CBCT applications have proved helpful in a multitude of  dental disciplines and the MFS needs to be aware of it. Its  indications include periodontal and endodontic assessment,  placement and evaluation of implants, evaluation of jaw  bones, temporomandibular joints, bony and _ soft-tissue  lesions, and alveolar ridge resorption and orthodontic   As the name suggests, it is a form of computed tomography  (CT). The basic process involved in CBCT is the scanning of  the region of interest using a cone-shaped X-ray beam, mak-  ing a single rotation around the vertical axis of the patient’s  head. The information obtained, from various angles about  the structures in the region of interest, is in a digitized format  relating to shape and density, which is then processed using   Conventional CT scanners CBCT makes use of a cone beam,  make use of afan beam and which radiates from the x-ray source  provide a set of consecutive in a cone shape, encompassing a  slices of image. large volume with a single rotation.  Makes use of a lie-down Makes use of a sitting up machine of  machine with a large gantry _— smaller dimensions   Higher radiation dose  Detector type X-axis only  Volume acquisition  requirements are sequential  multiple gantry rotations  Speed of examination is fast   CBCT occupies a special place in imaging of the Head  and Neck region. It offers a number of advantages over tradi-  tional CT technology. It has a multitude of uses in the dental  discipline, including dentoalveolar disease and anomalies,  jaw tumors, vertical root and dentin fractures, among others.  It has also had a positive impact on teaching students about  oral and maxillofacial imaging making them adept at operat-  ing equipment and related instruments, resulting in greater  accuracy in evaluation and analysis of the pathological char-  acteristics of the disease process leading to a proper final  clinical diagnosis. Both the traditional fan beam CT and  CBCT are third-generation CT scanners but are different in  some ways (Fig. 8.16a, b) (Table 8.1).   Gamma rays are a form of Electromagnetic radiation (EMR).  They are similar to X-rays but can be differentiated by the  fact that they originate from the nucleus. Gamma-ray pho-  tons have the highest energy with their waves having the  shortest wavelength in the EMR spectrum. The difference  between the two is that X-rays are produced by accelerating  electrons when they strike a target, while gamma rays origi-  nate from the nucleus of a radionuclide after radioactive  decay. Gamma rays damage the DNA of cells and it is this  action that is used in the treatment of cancerous tumors, care    being taken not to affect the DNA of the surrounding healthy  tissue cells [3].   Scintigraphy or radionuclide imaging is a modality that is  readily available and relatively inexpensive. One drawback  is that though it can provide specific information, the resolu-  tion is poor. It is a functional imaging modality and can  assess early physiological changes even before bone mineral  changes are evident. Bone scintigraphy is highly sensitive in  detection of skeletal osteoblastic activity and the process  involves uptake of the radiopharmaceutical Technetium-99 m  (Tc-99 m), by the mineral component of the bone due to its  affinity for bone. It has proven to be greatly useful in the  study of malignant lesions and also in the evaluation of  vascularized bone grafts used in reconstruction surgeries of  the maxillofacial region [4]. Another use of radionuclide  imaging is in evaluating patients with condylar hyperplasia.  In these patients, radionuclide imaging of the temporoman-  dibular joint is performed to exclude active condylar growth  and in planning the extent of orthognathic surgery. A pro-  gressive condition necessitates the removal of the entire con-  dyle and neck while trimming of the enlarged condyle  suffices otherwise [5].   PET also is a functional imaging technique. It is unique in  that it produces images reflecting in vivo changes in tissue  metabolism, linking the changes to malignancy. Body images  are produced when radiation is emitted from radioactive  tracer substances like Carbon-11, Fluorine-18, Oxygen-15,  or Nitrogen-13. When a positron emitted from the radioac-  tive substance collides with an electron in the tissue, gamma  rays are given off at the site, which are detected by a gamma  detector. FDG-PET/CT fusion scans of the head and neck are  not primarily for infection identification but for categorizing  a clinically questionable lesion as malignant or not.   CT scans detect changes in body structure and only con-  firms the presence of a mass. PET scan is different from CT  in that it can reveal the presence of disease earlier allowing  for quicker diagnosis, can detect the extent of disease and  whether a detected mass is benign or malignant, helps moni-  toring treatment and its effectiveness, and can detect abnor-  malities even before there is any anatomical change. This is  based on the fact that glucose consumption by malignant    cells and hence tissue is far higher than that of normal  tissue.   The scan involves intravenous injection of a radiolabeled  compound like 2-deoxy-2-(18F) fluoro-D-glucose (FDG).  After uptake of the compound, it undergoes further break  down in the cells. Since tumor cells have a high metabolic  rate, itis also metabolized by the tumor cells. FDG is metab-  olized to FDG-6-phosphate, but the tumor cells are incapable  of metabolizing it further and in consequence the FDG-6-  phosphate accumulates and concentrates within the tumor  cells. It is this accumulation that is detected and quantified.  As compared to normal tissue, the uptake of FDG by malig-  nant tissue is very high, making it a sensitive method to pick  up early malignant tissue [6].   When an X-ray photon is incident on tissue, it results in a  series of changes at the molecular and atomic level. The trans-  formed photon energy results in the discharge of an electron  and a free radical, or ionization in other words. Ionization  results in the production of a new molecule due to breakage of  enzyme bonds manifesting in the form of different biological  effects. These effects may be repairable when there is no  appreciable damage, or irreparable when there is definite  occurrence of damage, the adverse effect being cumulative in  nature.   Myths and Facts about radiation in the field of  Diagnosis: Many myths exist regarding radiation hazards  associated with medical diagnostic imaging. Possible rea-  sons for this are the available historical data, exaggerated  social media reports, results of experimental studies and the  complex nature of radiation biology making it difficult to  evaluate its mechanism of action. Historical data relates to  the reports of visible radiation hazards from studies on vic-  tims of the Hiroshima/Nagasaki bomb explosion in 1945  who were followed up for 15-18years. Exaggerated report-  ing by social media about nuclear reactor accidents like that  at Chernoby] add to the existing myths. The extremely short  time for which radiation interacts with matter (10>Sec) after    absorption, makes it difficult to study the complex nature of  radiation biology. The biological process of cell death can  take days to months, carcinogenesis can take years to occur  while generations may pass before a mutational change is  seen.   In reality, the dose of received radiation from man-made  X-rays that exist today is minute, in comparison with the  massive radiation exposure that occurred in the aforemen-  tioned examples. It is true that in the infant stage following  discovery of X-rays and its use in diagnosis, visible radiation  hazards did occur, which was due to ignorance in the under-  standing of its potential hazards and the use of crude equip-  ment resulting in high amounts of radiation leak. With  passage of time, we have learnt to put the benefits of X-rays  to full use, concurrently taking proper precautions to protect  ourselves from its hazardous effects. Over the years,  improvements in diagnostic equipment using ionizing radia-  tion have led to the production of newer equipment provid-  ing the best possible image quality with minimal radiation  exposure and improved devices that are protective against  radiation. Yet, the fact remains that the best method to reduce  the effects of radiation is using it only when it is an utmost  necessity [7].    This imaging modality does not involve the use of ionizing  radiation but makes use of magnetic and radiofrequency  energy to obtain information of the internal organs.  Components of an MRI unit include the magnet, the console,  and the computer.   Exploiting the body’s magnetic property forms the basis of  imaging using magnetic resonance. The human body is  abundant in atoms with odd number of protons, or in other  words ionized particles or charged atoms. A charged particle  spinning around its own axis creates a magnetic field around    itself behaving like a tiny bar magnet. Hydrogen represents  one such atom that is present in water molecules and there-  fore in all body tissues.   The random orientation of the hydrogen atoms cancels out  their magnetic fields and so there is no net magnetization at  rest. When these protons are placed in a strong magnetic field,  a net magnetization is produced that aligns parallel with the  main magnetic field. To influence the human body, the exter-  nal magnetic strength needs to be about 6000 to 80,000 times  the earth’s magnetic strength. The resultant net magnetization  acts as the source of the MR signal and is used to produce MR  images. Application of a radiofrequency (RF) pulse results in  absorption of energy from the RF pulse causing the net mag-  netization to rotate away from the direction of the main mag-  netic field, the amount of rotation or flip angle depending on  the strength and duration of the RF pulse. The strength and  duration of the RF pulse can be controlled such that the net  magnetization can be rotated to any angle [8]. Withdrawal of  the RF pulse results in the liberation of energy, with the emis-  sion of signals based on the density of protons or hydrogen  atoms. These signals are captured by the external antennae,  fed into the computer, and processed to produce the image.   e External magnets are of two types, the permanent magnet  and the electromagnet.   e Permanent magnets are cheaper with no significant recur-  ring cost. However, its limitations include limited strength  of less than 0.5 tesla, heavy nature making transportation  difficult, production of weak signals, and slower perfor-  mance with limited range resolution.   e Electromagnets work by the passage of high current  around ferromagnetic substances creating the required  magnetic field. They are faster, have better resolution,  produce better reconstructions, and are lighter than per-  manent magnets. The drawback is the production of large  amount of heat that needs cooling using Liquid Helium.  Other disadvantages include the high cost of infrastruc-  ture, high consumption of electricity, and recurring  expenses.   e Specific history relating to previous surgery with the use  of aneurysmal clips or metallic prosthesis needs to be  ascertained.   e Patient compatibility for the procedure needs to be evalu-  ated in view of the requirement of lying motionless for a  minimum of 30 to 40 min, e.g., Orthopneic patients,  COAD patients. Anesthesia might be required for agitated  patients and infants.    ¢ A double check for any metallic objects on the patient’s  body using a metal detector device is necessary.   ¢ Claustrophobic patients need to be reassured and put at  ease before the examination begins.   ¢ The procedure needs to be explained in detail prior to the  patient entering the MRI magnet room.    CT & MRI are complementary to each other. As far as the  MFS is concerned, thin-slice CT with reconstruction is  required while evaluating bony lesions, especially in cases of  trauma. MRI on the other hand is good for evaluation of soft-  tissue tumors and is contraindicated in penetrating injuries of  the eye (Table 8.2).   Images need to be  reconstructed in  multiple planes  following acquisition  of primary axial  sections. Direct  sagittal and coronal  slices are possible  except for TM joint.   Direct multiplanar  images can be primarily  acquired in any desired  plane.   Takes longer. Minimum  time required for scan of  any part is 40-60 min    MRI is contraindicated in  patients with pacemakers  or recently placed  implants. MRI  compatible supportive  gadgets: Pulse Oxymeter,  anesthesia equipment,  LV. stands, etc.   CT and MRI are sectional imaging methods, in which the  whole body or the region of interest is sectioned into serial  slices and further into cubes (Fig. 8.3a, b). Each slice surface  represents the corresponding sectional anatomy with each  slice being made up of small units or cubes with each cube  representing the basic nature of the tissue in the digital form  (Figs. and a, b). Different modalities produce var-  ied imaging appearances of the same structure. For instance,  if a coconut is imaged using different modalities, the fine  structural details of the interior of the tender coconut, and its  contents are better seen on CT and MRI (Fig. 8.19a-c).  Similarly, imaging of a pineapple in axial (Fig. a-d) and  coronal planes (Fig. 8.21a-c) and using the volume-rendering  technique (Fig. ) reveals varied appearances on CT and   To summarize, in sectional imaging, the region of interest  or the whole body is divided into slices and cubes with each  cube representing the basic tissue of that region with thinner  slices and smaller-sized cubes offering better resolution.    C Each axial slice is divided into small cubes loaded with digi-  talized values representing corresponding tissue volume called voxel.  Its surface represents a fraction of the grayscale image specific for that  region called pixel. Thinner the slice and smaller the pixel, better is the  resolution    Fig. 8.18 (a) and (b). Figures showing unit wise volumetric digitalized information of anatomical structures for retrieval and displayed as sec-    (a), (b), and (c). Imaging of tender coconut. (a) Conventional plain Radiograph. (b) CT Axial sectional imaging. (c) MRI sectional  imaging. Note: added information with each of these modalities    (a), (b), (c), and (d). Axial sectional images of pineapple taken at the same level (a) CT. (b, c, d) MRI various sequences. Note: superior  soft-tissue resolution in MRI, highlighting various components of soft tissue in various sequences    Fig. 8.21 (a, b and c). Various sequences of MRI of a pineapple showing multiplanar capability to procure sections in any desired plane without  reconstruction unlike CT    It seems implausible that sound waves can produce informa-  tive images of internal organs of a human body. Yet it is true  that technology has evolved so much over the years that it is  now possible to obtain information of body structures using  sound waves by making use of the echo and Doppler proper-  ties of sound waves.   Sound waves can be classified, based on their wavelength  and frequency as audible sounds (20 to 2000 cycles/sec),  infrasound (less than 20 cycles/sec), and ultrasound  (>20,000 cycles/sec). Ultrasound in the range of 2 to 20 MHz  is used in medical imaging [8]. The source of these ultrasound  waves is piezoelectric crystals. These crystals have the special  property of generating electrical pulses on being subjected to  pressure. In addition, the passage of electricity through the  crystals causes them to get compressed or deformed.  Essentially, these crystals are unique in that they have the dual  property of converting electrical energy into mechanical  energy and mechanical energy into electrical energy.  Intermittent passage of electrical current through the crystals  makes them alternate between compression and relaxation,  resulting in vibration of the crystal, in consequence producing  sound energy of small wavelength in the ultrasound range.   Devices, equipped with piezoelectric crystals, having the  capability to convert electrical energy to mechanical energy  and finally to sound energy as well as having the reverse  capabilities of converting sound energy to electrical energy,  are termed as Transducers.   Sound waves are useful in imaging due to their property of  Fig. 8.22 CT 3D surface rendering image of Pineapple echo/reflection and due to the Doppler effect. Echo property    refers to the property of sound waves to get reflected at the  interface of two media, the strength of the reflected sound  echo depending on the density difference of the media through  which they traverse. Reflected sound energy gets converted to  mechanical energy and finally to electrical energy on striking  the crystal, and this electrical energy is represented on a moni-  tor as bright dots of variable gray scales.   Varying density interfaces throughout body tissues, pro-  duces variable image brightness with gray scales ranging  between extreme bright dots to black dots, representing differ-  ent organ or tissue sections. The Doppler effect of sound refers  to the change in the apparent frequency of a wave when the  observer and the source move toward or away from each other.  Motion causes a change in pitch with a higher frequency being  heard when the sound source approaches the observer, and a  lower frequency being heard when the sound source moves  away. This Doppler property is used in evaluating the direction  and velocity of flow of blood in vessels. The transducer is con-  sidered as the fixed source of sound and the blood component,  mainly the RBCs act as moving reflecting bodies. At a given  point in the vessel by calculating the sudden change in the  frequency of reflected sound, we can calculate the velocity of  blood and also the direction of blood flow. This helps in the  evaluation of percentage of stenosis in a vessel.   A grayscale sectional image has specific echo texture based  on tissue content with the display mode being called as the  ‘B’ mode (Brightness mode) or grayscale mode. Higher  sound frequency provides better image resolution with delin-  eation of finer tissue components, however, at the expense of  depth of penetration. Higher-frequency transducers (7 MHz    Fig. 8.23 (a) and (b). Example of an elephant and an ant demonstrat-  ing their varying capability in picking up large and small objects from  varying distances—a pictorial representation for understanding the dif-    to 20 MHz) are hence used for imaging superficial structures  like cheek, the maxillofacial region, neck spaces, breast, thy-  roid, testis, eye, musculoskeletal system and skin, regions  where finer analysis of tissue structure is expected. Deeper  structures are evaluated by using transducers with frequency  in the range of 2 to 5 MHz.   The relation between frequency, resolution, and depth can  be understood well, using the hypothetical example of two  friends—an ant and an elephant (Fig. 8.23a, b). Both of them  are commanded to perform the same tasks, the first being to  pick up and bring back a crystal of sugar dropped at a dis-  tance of 100 cm from the start line and the second to pick up  and bring back a log of wood placed 100 meters from the  start line. Both of them proceed to perform the first task. The  ant being small is able to easily identify the sugar crystal and  get it back; however, the elephant keeps moving around  unable to identify the crystal. As to the second task, the ant is  able to travel only a short distance after which it dies of  exhaustion, unable to reach the log of wood while the ele-  phant travels the distance with ease and brings back the log  of wood.   The ant is comparable to the high-frequency short-  wavelength sound wave that is able to travel a short distance  and bring back finer information about superficial tissues. If,  on the other hand, it travels a long distance all its energy is  absorbed by interaction with tissues. The elephant is compa-  rable to the low-frequency sound wave with long wavelength  that can travel deeper into the tissues and get information of  deep structures, but limited tissue details. In a clinical setup,  both the ant (high-frequency sound) and the elephant (low-  frequency sound) are essential for evaluation, depending on  the clinical situation and region of interest.    ference in the penetration capacity of high- and low-frequency sound  waves. (Explained in the text)   The display of flow of blood in a vessel is color coded. The  flow toward the probe is depicted as red and flow away from  the probe is blue. Arterial and venous flow, in a given ana-  tomical region, is in opposite directions. Red generally rep-  resents flow in arteries, while blue represents venous flow.  Turbulent flow is depicted using a mixture of colors.   This display mode of Doppler conveys information about the  overall flow in a given tissue, for instance, assessment of  blood flow in a tumor. It helps to determine whether the  tumor is hyper- or hypovascular.   e Ultrasound imaging is inexpensive and is free from the  risk of radiation.   e Excellent soft-tissue resolution is possible and dynamic  studies too can be performed under ultrasound guidance.   e It is the first line of investigation for hepatic, biliary, and  renal disease and is an excellent modality for cyst  imaging,   ¢ Gynecological and prostate disorders are imaged using  endocavitary ultrasound, Doppler studies allow assess-  ment of blood flow, and real-time ultrasound imaging  helps in guiding interventional biopsies and drainages.   e A long learning curve exists for some areas of expertise  and image resolution is dependent on the machine that is  available. Ultrasound does not give information of struc-  ture behind a bone and also gas filled structures.   HRUSG is a grossly underutilized modality in evaluating  lesions of the maxillofacial region. This is due to the lack of  awareness of its application. The tissues in the maxillofacial  region are ideal for sonographic evaluation and hence is widely  applied to help diagnose a number of clinical conditions. It can  serve as the best possible initial parallel imaging investigation  for all the superficial soft-tissue structures of head and neck  region.   It is noninvasive and does not involve use of radiation.  There are no contraindications to the use of ultrasound, and it  can even be performed as a bed side examination. No prior  specific preparation is required except for shaving of the beard,  which might hamper the study. The study results are immedi-  ately available, and it is an excellent modality for evaluating  various soft-tissue planes of the cheek. Evaluation of various  anatomical spaces such as superficial masticator space, parotid  space, carotid space, superficial neck spaces, visceral space,  floor of the mouth, and all the infrahyoid neck spaces like the    submandibular and sublingual spaces are possible using  HRUSG, as are also pathologies like pre- and paravertebral  abscesses, cellulitis, Ludwig’s angina, and ranula [9].   High-resolution ultrasound is also capable of evaluating  the nature of lymph nodes, assessing fluid and solid compo-  nents and also assessing tissue vitality. Procedures like drain-  age of abscesses and biopsies can be conveniently performed  under ultrasound guidance. Being a highly economical imag-  ing modality, it is excellent for follow-up studies, excellent  as a screening method, and at most times proves to be the  conclusive examination [9].   Drawbacks include difficulty in assessing structures behind  bony elements and structures containing gas. In case of huge  masses, only partial information may be obtained, while short-  necked individuals and obese patients are difficult to evaluate.  Structures at the base of the skull cannot be evaluated as are  structures medial to ramus. Another limitation is that ultrasound  cannot provide information about structures behind bone or any  gas-filled structure. Scanning using a hockey stick probe might  help overcoming this limitation. Scans need to be performed by  individuals having vast experience and expertise.   There needs to be an increase in awareness regarding the  developments in the application of HRUSG in the maxillofa-  cial region and a close interaction between the surgeon and  the sonologist for creating an atmosphere of better under-  standing among them.    Medical thermography is used for early preclinical diagnosis  and treatment of homeostatic imbalances. It is noninvasive  and safe since it does not use any radiation. It makes use of  body heat to diagnose a wide range of health conditions. By  using high-speed computers and thermal imaging cameras,  body heat is processed and recorded in the computer as an  image map that can be analyzed. The analysis is based on  determining the presence of abnormal hot and cold areas that  can relate to different conditions.   A variety of conditions related to blood flow in the head and  neck vessels can be assessed by thermal imaging. Easy visu-  alization of facial blood vessels by thermography is possible  because of its superficial location. Common venues of ther-  mographic use in the head and neck region include evalua-  tion of pain related to differentiation of different types of  headache, facial nerve injury following a blow to the face or  an accident, and visualization of disorders of the temporo-  mandibular joint.    8.10 Role of Chest Radiograph  in the Practice of Maxillo Facial  Surgery    One of the most frequently requested investigations by an  MEFS is the Chest radiograph. Hence, interpretation of chest  radiographic findings is of prime importance in determining  the patient’s clinical status.    An ideal chest radiograph, in terms of quality, is one that  fulfills the following criteria (Fig. 8.24)   — Purpose—Avoiding problems related to improper  positioning that can obscure certain lung regions like  the hila and mediastinal lines, can prevent clarity of  borders, or can result in distorted position of struc-  tures like the trachea, which can be misinterpreted as  a paratracheal mass.   should be out of the lung field  (c) Inclusion of anatomical structures.   — Ideal radiograph—must include the lower neck,  both shoulders, lateral chest walls, and both dia-  phragms, including upper abdomen   — Ideal radiograph—must include the patient name,  medical record number, date of acquisition, and the  side marker (the most important of all)    The aim of reading a chest radiograph is to scan the whole  image in a methodical way such that no anatomical part  included in the radiograph is missed. While interpreting the  radiograph, it is necessary for the interpreter to actually feel the  structural component of the anatomical part being evaluated.   If, for example, a rib is being evaluated it needs to be traced,  consciously keeping in mind, its component parts, the two cor-  tical margins seen as white lines representing compact bone  and the less dense central component representing marrow  with fine normal trabeculae. This is in addition to evaluation of  its number and shape. This meticulous evaluation will prevent  missing of rib lesions and interpretation of the lesion is easier  with prior knowledge of possible pathologies that affect ribs.   Many ways of methodical scanning have been docu-  mented in literature. The WHO-recommended method  involves chest radiographic evaluation by beginning at one  corner of the film, continuing to horizontally scan till the  other corner, followed by sliding down and again continuing  to scan toward the other edge, continuing till the whole of the  radiograph has been scanned. As part of the examination,  both sides of the chest must be compared.   It can be likened to the painting of a wall by a professional  painter with a perfect finishing touch. Once the initial pri-    mary scan is complete, specific areas called the lawyer’s  zone or hidden areas of the lung need to be looked over a  second time. These areas include both the hilar regions, both  cardiophrenic regions, both apical and clavicular regions,  and finally also through the heart and diaphragms.    8.10.3.1 Preoperative evaluation  i. Cleft lip and palate/any other congenital maxillofacial  anomaly  ii. Infections of the maxillofacial region  iii. Known malignancy in maxillofacial region  iv. Trauma.    8.10.3.2 Intra- / Postoperative recovery room  i. Sudden choking and breathlessness  ii. Sudden cyanosis  iii. Sudden cough  iv. Chest pain.  v. Fever  vi. Evaluation of chest tubes and catheters (suggested refer-  ence for further reading).   It is one of the most common terminologies used in  Radiology. Clinicians and pathology textbooks, however,  commonly use the term pneumonia. Any infection of the  lung parenchyma is broadly referred to as pneumonia.    Involvement of the alveolar components of the lung paren-  chyma by the infection is called parenchymal consolidation  [10]. It is a disease process in which the air normally present  within the small lung air sacs (alveol1) is replaced by liquids  like pus, blood, or other fluids, or solids like tumor cells.   Radiologically, consolidation appears opaque [11].  Normally, the alveoli are filled with air and so the normal  opaque pulmonary vasculature can be visualized against the  dark background of air. However, as discussed earlier, the  replacement of the air spaces by any form of fluid or solid  material makes the normally visualized pulmonary vessels  inapparent with the air containing bronchi being visualized  against the opaque background, which is called the air bron-  chogram (Fig. 8.25a—c).   The consolidation process involving a single lobe and  limited by a fissure is called as lobar pneumonia, while the  involvement of the entire lung is known as whole-lung con-  solidation. At times, the process is not as uniform and is dis-  tributed in the form of patchy opacities with intervening  nonopacified alveoli, an appearance referred to as the air  alveologram, which is seen in Bronchopneumonia.   Maxillofacial surgeons are often faced with the problem of  patients going into a state of sudden breathlessness in the  postoperative recovery room for which the MFS asks for a  portable chest radiograph. One of the most common causes  of sudden breathlessness in the postoperative recovery room  is pulmonary edema. The common confusion for which MFS  postgraduates seek the radiologist’s opinion is whether the  cause of breathlessness is bronchopneumonia or aspiration  bronchopneumonia.   In case of acute cardiogenic pulmonary edema caused  either due to left ventricular failure or fluid overload, the  characteristic radiographic abnormality would reveal bilat-  eral symmetrical areas of consolidation predominantly in the    Fig.8.25 (a) and (b) Consolidation: Homogeneous opacities with “Air-bronchogram” sign. (c) Schematic diagram showing group of alveoli filled    perihilar and lower lung zones [10] (Fig. a, b).  Noncardiogenic pulmonary edema caused by different  pathologies, including fluid overload, acute glomerulone-  phritis and adult respiratory distress syndrome among others,  affects the permeability of the pulmonary capillary mem-  brane (Fig. 8.27). The distribution can vary depending on the  position of the patient. The opacities seen on the portable  radiograph should not be confused with the appearance of  pneumonia (Fig. 8.28).   Rare causes of unilateral pulmonary edema, including  raised intracranial pressure and the administration of fluid  through the central venous catheter inadvertently placed in  the pulmonary artery, need to be kept in mind as well.   Diminished air within the lung associated with reduced lung  volume is termed atelectasis manifesting radiologically as  pulmonary opacity accompanied by volume loss. The causes  are varied, including resorption, relaxation, adhesive and  cicatrization atelectasis. Of these, the form of atelectasis a  maxillofacial surgeon commonly deals with is resorption  atelectasis, where there is an obstruction in the communica-  tion between the alveoli and trachea. The obstruction may be  at any level from the common air way to the segmental bron-  chus; however, common air way obstruction resulting in  bilateral atelectasis is a rare occurrence [11]. Radiologically,  the appearance is that of a homogeneous opacity without an  air bronchogram sign, with loss of lung volume and displace-  ment of structures toward the opacity.    » (a) Congestive cardiac failure with cardiomegaly and pulmonary edema. (b) Resolution of pulmonary edema after treatment    Fig. 8.27. Noncardiac pulmonary edema in a patient with renal failure    The maxillofacial surgeon commonly comes across simi-  lar radiographs in the postoperative recovery room. The  commonest cause of this is the inadvertent placement of the  endotracheal tube into one bronchus, causing occlusion of  the other bronchus, and resulting in atelectasis as a    consequence. Early detection and diagnosis with readjust-  ment of the endotracheal tube is bound to be life saving,  helping prevent long-term complications (Fig. 8.29a-c).  Thick mucus plugs are other common occluding elements,  seen in postoperative recovery rooms resulting in lobar or  segmental opacities with loss of volume. Again, early detec-  tion and good respiratory physiotherapy are keys to improved  lung compliance with a radiograph taken at a later date as  follow-up.   Normally negative intrapleural pressure is caused by com-  peting thoracic pressures. Lung elasticity and surface tension  of the alveolar fluid create an inward tension, pulling the  lung inward, which is countered by opposing forces from the  pleural fluid and thoracic wall, the pleural cavity surface ten-  sion, and the parietal pleural attachment to the thoracic wall  causing outward pull of the lungs. The outward pull is  slightly higher than the inward pull with a negative intrapleu-  ral pressure of about -4 mm of Hg. When this intrapleural  negative pressure is lost as occurs commonly in cases of  pneumothorax or pleural effusion, the lung has a natural ten-  dency to recoil, with the loss of lung volume being propor-  tional to the amount of air or fluid collected in the pleural  space [11].   The presence of air in the pleural space is called pneumotho-  rax, the most common cause of which is trauma either acci-  dental or iatrogenic. In the absence of such causes, it is called    spontaneous pneumothorax. Radiological findings of pneu-  mothorax include increased peripheral translucency, absence  of lung markings within this area of translucency, and the  identifiable visceral pleural margin of the collapsed lung  (Figs. 8.30 and 8.31). The detection of a pneumothorax  should prompt the search for an underlying cause like a frac-  tured rib or a ruptured bulla or iatrogenic causes like a cen-  tral venous catheter procedure. Associated lesions like  pneumomediastinum and surgical emphysema should also  be looked for.   A maxillofacial surgeon might have to read supine porta-  ble radiographs of patients presenting with clinical signs  suggesting respiratory distress and the presence of pneumo-  thorax might be missed. In such a scenario, the MFS should  look for radiographic evidence of pneumothorax at sites  adjacent to the diaphragmatic silhouettes on either side and  the cardiophrenic and costophrenic angles and he should  also be able to appreciate the appearance of an exceptionally  sharp cardiac border [11]. The MFS needs to be aware that  air trapped within the skin folds can mimic pneumothorax  (Fig. 8.32).   Identification of an air fluid level would prompt the diag-  nosis of a hydropneumothorax. It is difficult to characterize  the nature of the fluid as being transudate, exudate, blood, or  chylous. An MFS may be unable to diagnose a hydropneu-  mothorax, on an AP supine portable radiograph as the fluid  level will not be identified. Here, the collapsed lung tends to  float on the fluid, which is dependent posteriorly giving a  veil effect (Fig. 8.33).   It is the collection of air within the pleural boundaries of the  mediastinum and can arise secondary to barotrauma from  mechanical trauma, intrathoracic, or iatrogenic trauma and  infection or can occur spontaneously. A radiographic diagno-  sis of pneumomediastinum requires depiction of normal ana-  tomic structures being outlined by air as they leave the  mediastinum. The mediastinal air can cause elevation of the  thymus, collect anterior or posterior to the pericardium, sur-  round the pulmonary artery or its branches, or can collect  adjacent to the major aortic branches or major bronchi  (Fig. 8.34).   Most cases of pneumomediastinum described in maxil-  lofacial surgery literature are as a result of dissection of air  down the fascial planes of the neck. Chest radiographic  findings need to be carefully examined to make the diag-  nosis of pneumomediastinum, which is crucial to the MFS  in planning appropriate treatment of affected patients. On  rare occasions, a significant amount of air in the mediasti-  num can cause vessel or tracheal obstruction and induce  symptoms and signs of tamponade and decreased venous  return.    the (Lt.) Bronchus. (b) Schematic diagram showing loss of volume of  alveoli as seen in collapse with absence of air. (c) Reversion of normal  left lung aeration after repositioning of endotracheal tube    Fig. 8.29 (a) Whole lung collapse: Left hemithorax is homogenously  opaque with loss of volume of left lung with displacement of mediasti-  num to left. Note: Abnormal placement of endotracheal tube blocking    @©Association of Oral and Maxillofacial Surgeons of India : aa  ©Association of Oral and Maxillofacial Surgeons of India    3 Right-sided hemopneumothorax with multiple rib fractures  as seen in supine radiograph   Though subcutaneous emphysema or surgical emphysema  actually means gas in the subcutaneous tissues, it also  includes soft-tissue emphysema that dissects into the deeper  soft tissues and musculature along fascial planes. The trans-  lucent air spreads over the chest wall and axilla into the root  of the neck. Fascial planes clearly outline the pectoralis mus-  cle and neurovascular bundles in neck (Fig. 8.35a, b). If  trauma is the cause, the gas by itself may not need treatment,  but its identification is of importance as it may be the only  indication of the presence of other serious injuries requiring  urgent management. Surgical emphysema can uncommonly  occur as a serious complication of oral and maxillofacial sur-  gical procedures. It may also occur following teeth extrac-  tion, endodontic treatment, or procedures like restorative  dentistry, periodontal and temporomandibular joint surgery,  or facial fracture repair.   For all intents and purposes, a nodule seen in the lung (espe-  cially in the lower zones) should be considered as metastasis  unless proven otherwise, by a maxillofacial surgeon.    Pulmonary nodules can be characterized, based on some  signature findings. In the absence of these findings, the nod-  ule remains nonspecific. Common causes of pulmonary nod-  ules are granulomas, bronchogenic cysts, hydatid cysts,  hamartomas, pulmonary hematoma following laceration,  rheumatoid nodules, fungal granulomas, and pulmonary  metastasis.   Tuberculomas usually range in size from | to 3 cm in  diameter, have central calcific lesions, and are surrounded by  satellite scarred lesions. They are commonly seen in the  upper zones, but they can occur anywhere in the lung  (Fig. 8.36).   Bronchogenic cysts are well-defined nodules, around 3 to  4 cm in size, usually seen in the parahilar region, and are  sometimes purely in the mediastinum (Fig. 8.37a-e).   Hamartomas are nodules that can occur anywhere in the  lung having well-defined margins with central popcorn-like  calcification (Fig. 8.38a, b).   Hydatid cysts, too, can occur anywhere in the lung. They  have a stenciled outline and vary in size from 1 to 10 cms.  The radiographic air crescentic sign is pathognomonic of a  hydatid cyst, appearing like the arc of the moon caused by  the separation of the endocyst from the exocyst. Continued  separation of the endocyst from the exocyst results in an air  fluid level typically called the ‘water lily’ appearance.  Pulmonary hydatid cysts do not calcify.   Presence of a solitary nodule in the lower lung without  any characteristic findings makes pulmonary metastasis a  strong possibility, which should be further evaluated with  imaging and HPR. Multiple nodules of varying sizes in the  lower zones are very much suggestive of pulmonary metas-  tasis.(Fig. 8.39a, b).    A maxillofacial surgeon should be capable of identifying  all of these causes of sudden onset of breathlessness in a  postoperative patient in the event of the absence of availabil-  ity of expert radiological opinion and act accordingly. They  also need to be aware that patients on ventilators may develop  ventilator-dependent complications.   1. Magnetization Transfer Imaging  This is a modified MRI study that helps in  e Prediction of whether the primary tumor is benign or   malignant (possible in 80 to 90% cases).  e Differentiation of reactive versus   2. MRI-guided biopsy procedures need MRI compatible  equipment. The procedures are feasible and are usually  done in cases that are not amenable to USG guidance.    Fig. 8.37 (a), (b), and (c). Preop chest radiographs of a patient with cleft lip presenting with dyspnea, more with changing position. (d) and (e)  Mediastinal mass—Bronchogenic Cyst confirmed on CT    Fig. 8.40 (a), (b), and (c). Foreign body, a coin in the cervical esophagus    8.11 Role of High Resolution  Ultrasonography (HRUSG)  as a Diagnostic Aid in the Practice    Primarily the use of HRUSG in the maxillofacial region is  directed toward investigation of the cheek and the structures  adjacent to it. Despite the layers of the cheek and the adja-  cent structures having a classical sonographic appearance,  literature available on HRUSG of the cheek is limited.  Having proper understanding of the relevant anatomy is criti-  cal in discerning the wide range of diseases affecting this  region. Evaluation of these lesions by ultrasound is possible  only once the normal ultrasound anatomy at various levels is  defined and a comparison of the suspicious lesion with the  normal expected appearance is made. An original attempt  toward this goal was made at our institute with comparison  of normal cadaveric sections at corresponding levels taken  by HRUSG.   High-resolution ultrasonography has broad applications  in the maxillofacial region especially in the cheek, which    include evaluations of the unilateral or bilateral swollen  cheek painful or pain less, restricted mouth opening, painful  chewing without obvious clinical findings, and varied causes  of facial swelling. Since early detection decisively influences  patient prognosis in case of malignancy, it is one of the prime  concerns in a presenting patient. Further, differentiation of  lesions as being of benign, malignant, infective, or inflam-  matory etiology is important in deciding on a treatment plan.  HRUSG should however be used to complement and not  replace other imaging modalities as it does have its  limitations.   Compared to other facial components, the cheek is pre-  dominantly composed of adipose tissue and is relatively  small in size. Swelling of the cheek is easily visible and pal-  pable in most patients presenting with cheek masses. Most  lesions have nonspecific characteristics on computed tomog-  raphy (CT) and magnetic resonance imaging (MRI). In con-  trast, HRUSG is ideal for evaluation of cheek lesions,  because of its capability to differentiate between tissues like  skin, fat, muscle, gland, ducts, and vessels especially since  bony and gaseous interfaces are absent. Further, the superfi-  cial location of the cheek makes it easily accessible to ultra-  sound. Vestibule can be evaluated with fruit jelly technique  obliterating the void space.   This short review attempts to aid the MFS in his under-  standing of HRUSG of the maxillofacial region, with special  reference to the cheek.    In simple terms, the cheek is the fleshy portion of the face,  below the eye, extending from the angle of the mouth to the  ear. Anatomically, it pertains to the buccomasseteric region  comprising the buccal space and its contents, masseteric and  buccinator muscles, the buccal fat pad, and Stenson’s duct.  The region is continuous anteriorly with the lips. Its exter-  nal anterior demarcation is formed by the nasolabial fold and  groove extending from the side of the nose to the angle of the  mouth. The mucosa lining the inner aspect of the cheek  adheres to the buccinator muscle, while the gingival mucosa  covers the mandibular and maxillary alveolar processes. The  gingivobuccal sulcus is the junction formed between the gin-  gival and buccal mucosae. The vestibule is the region of the  mouth between the teeth, lips, and cheek, which is bound  superiorly and inferiorly by buccal mucosal reflections onto  the mandible and maxilla. Posteriorly the vestibule is con-  tinuous with the oral cavity proper (Fig. 8.42) [12, 13].    The part of the oral cavity located underneath the tongue is  called the floor of the mouth and it can be involved by a  myriad of pathological processes. Superficial lesions involv-  ing the mucosal surface are easily visualized and may not  need imaging. Disease involving the deeper structures of the  floor needs to be evaluated by imaging, and HRUSG is many  times the first line of investigation because of its superior  soft-tissue differentiation capability, thus allowing for clear  depiction of contents of the floor [14].    Inflammatory processes, malignancies, and vascular  abnormalities can affect the floor contents, while certain  conditions like ranula and obstruction of the submandibular  gland are specific to this location [14].    Normal Ultrasound Cheek  Various cheek layers have varying sonographic echogenicity  and echotexture, and hence ultrasound is an invaluable tool  in the characterization and localization of cheek lesions.   Depending on tissue density, the sound wave transmission,  absorption, or reflection capability of each tissue varies.  Tissues, having high water content like blood, appear black  and are called anechoic because they conduct sound waves  well. In contrast, tissues that are poor conductors reflect most  of the sound wave energy back to the transducer appearing  bright and are termed hyperechoic, examples of which include  bones, tendons, and fascial planes. Tissues like muscle reflect  less of the sound wave energy and have a hypoechoic appear-  ance. In the cheek, the mucosal and submucosal layers appear  hyperechoic, the mucosa more so. Muscle tissue appears  hypoechoic, while fatty tissue appears echogenic (Fig. 8.43).   Compared to other imaging modalities, ultrasound has  proven to be superior as regards identification of small  lesions, detection of lesion plane, and lesion characterization  (Fig. 8.44).   The cheek layers and neighboring structures that can be  identified by HRUSG are.    For ultrasound examination, the cheek is considered to be a  rectangular area bordered as follows (Fig. 8.45).    ¢ by an imaginary line beginning at the angle of mandible  and extending along its lower border to the level of angle  of mouth inferiorly,   ¢ by an imaginary line beginning at the angle of mandible  and running along the posterior border of the mandibular  ramus to include the temporomandibular joint posteriorly,   ¢ by an imaginary line along the zygomatic arch superiorly  and,   ¢ by an imaginary vertical line at the level of angle of mouth  that joins the superior and inferior lines anteriorly [15].  Various techniques, including the resting (neutral) and    Fig. 8.44 (a-d) Cheek anatomy—a comparison. Comparative cheek anatomy- (a) cadaveric specimen, (b) CT, (c) MRI, and (d) Ultrasound    Limitation: Occurrence of mirror image artifact.  Less sensitivity in evaluation of lesions of the vesti-  bule (gingivobuccal sulcus).   e Patient is instructed to feel the cheek lesion with the  tongue.   e Lesion is brought closer to the probe creating a better  acoustic window.   e Lesions of the superficial buccal mucosa and tongue  lesions on its anterior half and corresponding lateral  borders can be evaluated better.   Advantage: Better visualization of lesion details.  Limitation: Inaccessibility to tongue lesions along  the posterior half and corresponding lateral borders.  (c) Fruit Jelly Technique.  (Figs. 8.49a, b, and 8.50a—d)  ¢ Commercially available edible “Fruit jellies” are    ©Association of Oral and Maxillofacial Surgeons of India placed in the upper and lower gingivobuccal sulcus.  e Patients are then instructed to close their mouth and  Fig.8.45 Area of Cheek ultrasound study ultrasound is performed.  Advantages:  (a) Resting (Neutral) and Puffed (Blow out) Cheek Technique ¢ Useful in elderly and facial nerve palsy patients having  (Figs. 8.46 and 8.47). difficulty holding puffed cheek for prolonged periods.  e Patient is instructed to blow, and ultrasound is per- ¢ Absence of artifacts due to vestibular air.  formed in puffed cheek status. ¢ Enhanced structural delineation and better evaluation  e Images obtained in axial and coronal planes. of vestibular extension of lesion.  Advantage: Improved visibility of cheek layers and Limitation: Inability to evaluate lesions involving far pos-    Fig. 8.46 Cheek layers by  “Puffed Cheek” Technique.  (1) Mucosa. (2) Submucosa.  (3) Buccinator. (4) Buccal fat.  (5) Subcutaneous tissue. (6)  Skin    Fig. 8.47 (a, b) Cheek layers by “Puffed Cheek” Technique. m-mucosa, sm-submucosa, b-buccinator, bf-buccal fat    Fig. 8.48 (a), (b), and (c). “Tongue Touch” Technique. Anterior tongue, its tip and lateral borders and cheek layers    Fig. 8.49 (a) Axial panoramic (b) Coronal Cheek layers by “Fruit Jelly” Technique. (1) Jelly (2) Angle of mouth (3) Alveolar process (4) Masseter  (5) Mandible (6) Parotid (7) Maxilla (8) Mandible (Asterisk)- Upper and lower gingivobuccal sulcus    Fig. 8.50 (a,b, c, and d).Cheek layers by “Fruit jelly” Technique. Panoramic axial slices. Coronal slices showing superior and inferior vestibules  along with layers of cheek/alveolar surfaces    HRUSG Cheek: Scope of Use and Limitations  Scope of practice of HRUSG cheek includes    Cases where limitations are posed by the clinical presen-  tation as in case of trismus or lesions that mimic others in   Estimation of the extent of a lesion, thus helping in tumor  staging    Cases where the use of plain radiography is limited  Inherent drawbacks of imaging modalities like CT and  MRI and their high cost   Difficulty in obtaining information of intact bone  Intra-articular structures of the temporomandibular joint  Postoperative scar tissue or a large external wound   Swelling of the face involving the midline or parasagittal  plane, floor of the mouth, TM joint region, submandibular  region, nose, lip, gums, etc.    Cheek—Growth, hemangioma, lymphangioma, Oral sub-  mucous fibrosis, abscesses, discharging sinuses, etc.  Masseter—evaluation of contraction, benign hypertrophy,  trauma, Space infection, trauma, etc.    (a, b, c, and d).Cheek cellulitis with evolving abscess. Diffuse soft-tissue thickening, edema of deep subcutaneous fat plane, edematous  buccinators and submucosal plane with mild echogenic tracking collection within the fascial planes    Fig. 8.52 (a, b and c). Cheek abscess. Focal organized thick echogenic collection in the deep subcutaneous plane with minimal extension into  buccinator muscle (45 year old male, with habit of chewing betel nut)    (b) Cheek abscess (Fig. 8.52a-c). (f) Painless unilateral swollen cheek (Intramasseteric  (c) Chronic osteomyelitis mandible (Fig. 8.53a, b). lipoma) (Fig. )).  (d) Cysticercosis parotid (Fig. 8.54). (g) Stenson’s Duct calculus (Fig. 8.61a, b).    (h) Polycystic disease of parotid (Fig. a, b).  2. Benign Pathology.   (b) Lesion at opening of Stenson’s Duct (Fig. a, b). (a) Buccal mucosal malignancy with intact submucosa  (c) Intraoral Mucocele (Fig. 8.57a, b). and buccinator (Fig. 8.63).   (d) Cheek lymphangioma (Fig. 8.58a—d). (b) Buccal mucosal squamous cell carcinoma (Fig.    Fig. 8.55 (a, b and c) Oral submucosal fibrosis. Axial slice showing thickening of the submucosal layer in OSMF in comparison to the normal    (a) and (b). Tiny calculus of about 1.2 mm revealed by HRUSG at Stenson’s duct opening. (Pain while chewing food. No swelling)    Fig. 8.57 (a) and (b). Intraoral Mucocele. Well-defined cystic lesion in the submucosal layer with internal minimal echogenic contents. Possible  diagnosis of mucocele given, later confirmed by HPR. (35 year old female, presenting with right-sided cheek swelling and mild pain)    Fi 58 (a, b, c, and d). Cheek lymphangioma. Fluid-filled cystic | confirms hyperintense fluid along left side of cheek extending into  lesion deep to submucosal layer with deep space extension adjacent to _infratemporal fossa (25 year old male, presenting with soft, painless  the masseter medial to mandibular ramus MRI coronal T2W imaging swelling of left cheek)    Fig. 8.59 (a) and (b). Epidermoid cyst of cheek. Well-defined complex cystic lesion in the subcutaneous plane with internal echogenic contents  causing displacement of underlying cheek layers (28 year old male presenting with painless left cheek swelling)    Fig. 8.60 Intramasseteric Lipoma. Elongated intramuscular lesion  isoechoic to the subcutaneous fat with internal echogenic strands repre-  senting intramasseteric lipoma. (30 year old female, presenting with  painless swelling of cheek)    Fig. 8.61 (a) and (b). Stenson’s duct calculus. Hyperechoic calculus in the Stenson’s duct with nondilated duct proximal to the calculus (23 year  old male, with history of intermittent pain on right side of the cheek)    (a) and (b). Polycystic disease of parotid. (22 year old male Bilateral painless swollen cheek 7-8 yrs duration)    Fig. 8.63 Buccal mucosal  malignancy with intact  submucosa and buccinator.  Growth predominantly  involving the mucosa, distinct  from submucosa (between  asterisk) buccinator (star)  appears normal. (55 year old  male with irritating  nonhealing ulcer left cheek)    Fig (a, b, and c). Early Carcinoma of the cheek better seen on HRUSG than by CT slice at the same level. Proved by Histopathology (52  year old male with squamous cell carcinoma of the buccal mucosa)    Fig. 8.66 (a) Buccal  mucosal carcinoma (Resting  phase). (b) Buccal mucosal  carcinoma (Fruit jelly  technique). Patient was unable  to perform the puffed cheek    Fig. 8.67 (a,b and c).  Superior vestibular malignant  mass. Coronal sections  revealing predominantly  hypoechoic, superior  vestibular mass with irregular  margins extending into cheek  layers and causing underlying  bony destruction. Comparison  between (a) neutral cheek,  (b) fruit jelly Technique and  (ce) CT    a f -E- A  @Association of Oral and Maxillofacial Surgeons of India    Fig. 8.68 (a) and (b). Tongue malignancy against cheek wall. Irregular lesion along the Right anterolateral margin of the tongue by “Tongue  touch” technique. Few enlarged lymph nodes are also noted with loss of hilar anatomy representing metastatic lymph nodes. (40 year old male,  with complaint of swelling over the tongue)    Fig. 8.69 (a, b, c, and d) Buccal malignancy with mandibular infiltra- | buccinator muscle. Focal cortical break is also noted in the mandibular  tion. Heterogeneous mass lesion along the buccal mucosa extending bone with intraosseous infiltration. (48 year old male tobacco chewer  into lower buccogingival sulcus with infiltration into submucosa and presenting with right cheek swelling)    Fig. 8.70 (a, b, c, and d) Arteriovenous malformation (AVM) cheek. _ tance flow suggestive of AVM. (40 year old female presenting with his-  Focal soft-tissue thickening with internal hypoechoic areas. Doppler _ tory of swelling and intermittent pain)  study shows multiple vascular channels with high velocity, low resis-    Fig. 8.71 Cheek  Hemangioma. Mixed echoic  hemangioma with phlebolith.  Absence of flow signals due  to low-velocity flow    It is extremely difficult to limit radiology to a chapter and  what has been written does not represent the whole of max-  illofacial radiology. Only the relevant aspects and the bare  minimum essentials of radiology for maxillofacial surgeons  have been covered in this chapter. The entire range of radi-  ology for maxillofacial surgeons, dealing with surgical  problems pertinent to the maxillofacial region, would  require more expansive and elaborate writing.   This chapter on radiology provides an outlook to the sur-  geon, who can proceed to applying radiology in his everyday  surgical practice. In the event of encountering any lacunae in  the book, the MFS must refer to the textbooks dedicated to  maxillofacial radiology. Being a surgeon, the MFS should be  aware of the use of the chest radiograph and its applications  in his practice. The role of high-resolution ultrasonography  has also been emphasized in this chapter. Dental radiology,  both extra and intraoral, has not been included since all max-  illofacial surgeons have extensive knowledge of the same in  their surgical practice.   Since it is the MFS who is acquainted with the patient’s  clinical status, he must properly plan the imaging pathway    for the patient. It is for this purpose that the MFS should be  aware of the various imaging modalities as regards their  nature, mode of image formation, their usefulness over other  modalities, and their drawbacks. Radiation safety and cost  effectiveness of a specific imaging modality also need to be  kept in mind. The imaging method selected should be one  that provides the required information within the shortest  time possible, be the safest option for the patient, and be the  most economical, while at the same time providing maxi-  mum information.   The MFS can commence with simple basic imaging  methods like plain radiography or USG and later proceed to  higher imaging methods in case the basic methods were not  enough to satisfy the surgeon’s needs for patient manage-  ment. A recent costlier imaging method does not necessarily  mean it is the best. Many times, it is the simpler basic imag-  ing methods that provide more crucial findings that help in  understanding complex disease processes.    Acknowledgments The authors would like to acknowledge & thank  Dr Niranjan Kumar, M.Ch FRCS. ; Honorable Vice-Chancellor, Shri  Dharmasthala Manjunatheshwara University for his valuable construc-  tive suggestions and constant support towards this endeavour.    References 9. Singh GP, Dogra S, Kumari E. Ultrasonography: maxillofacial  applications. Annals of Dental Specialty. 2014;2(3):104~—7.    E, Lenarda RDI. Comparison of orthopantomography (OPG) and 11. Fraser RS, Muller NL, Colman N, Pare PD. Fraser and Pare's diag-    computed tomography (CT) accuracy in predicting inferior alve- nosis of diseases of the chest. 4th ed. Philadelphia: W.B. Saunders;  olar nerve injury following lower third molar surgical extraction 1999    [Internet]. 2017 [cited 2019Jun3}. Available from: https://www. 12. Christopoulos A. Mouth Anatomy [Internet]. Overview, Gross  researchgate.net/publication/3 19548814 _Comparison_of_orthop- Anatomy: Oral Vestibule, Gross Anatomy: Oral Cavity Proper.  antomography_OPG_and_computed_tomography_CT_accuracy_ 2015 [cited 2019Jun5] ,    eases. J D ent Educ. 2002;66(12):1381—7. a and evaluation of neoplastic conditions. J. Evid. Based Med.  5. Appadurai R, Lingeshwar D, Venugopal S, Christina RD. Bone Healthc. 2016;3(34):1649-55    scintigraphy as a diagnostic tool in condylar hyperplasia [Internet].  2017 [cited 2019Jun3]. Available from: http://www.joomr.org/arti-  cle.asp?issn=232 1-384 1;year=2017;volume=5;issue=3;spage=84;e  page=89;aulast=Appadurai Further Reading   6. Griffeth LK. Use of PET/CT scanning in cancer patients: techni-  cal and practical considerations [Internet]. Proceedings (Baylor  University. Medical Center). Baylor Health Care System; 2005  [cited 2019Jun4]. Available from: https://www.ncbi.nlm.nih.gov/  pme/articles/PMC1255942/   8. Pooley RA. AAPM/RSNA Physics Tutorial for Residents  Fundamental Physics of MR Imaging [Internet]. 2005 [cited  2019Jun3]. Available from: https://pubs.rsna.org/doi/pdf/10.1148/  rg.254055027    Mosier K. Functional imaging of swallowing. In: Mukherji SK,  Casterlijins JA, editors. Head and neck imaging. Berlin: Springer;  2000. p. 79-86.   Yousem DM (2000) Magnetization transfer imaging of the Extracranial  head and neck. In: Mukherji SK, Casterlijins JA (eds). Modern head  and neck imaging. Springer, Berlin, pp1—16.   Sanjay N. Jain (2019) a Pictoral essay: radiology lines and tubes in the  intensive care unit. Indian J Radiol Imaging. 2011;21:182-90.    Open Access This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.  org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropri-  ate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.   The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in  a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.   A study comprising data from 56 countries in 2004 stated  that the annual major surgery volume was estimated to be  187-281 million operations, accounting for approximately  one operation annually for every 25 human beings alive [1].  In subsequent studies, data were obtained from a total of  194 Member States of the World Health Organization for  the years 2005-2012. According to these studies, 312.9 mil-  lion operations took place in 2012, showing an increase  from the 2004 estimate of 226.4 million operations. 6.3%  and 23.1% of operations were carried out in very-low and  low-expenditure countries representing only 36.8% (2573  million people) and 34.2% (2393 million people) of the  global population of 7001 million people, respectively [2].  The incidence of postoperative infections reported among  the developed countries like UK and USA was approxi-  mately 5% and 5—6%, whereas in developing countries like  India it is much higher, accounting for approximately  10-25%. [3, 4].   The main problem encountered in the practice of surgical  safety is that existing safety practices are not adequate in  some countries. Lack of resources is the main reason behind  this, particularly in developing countries. Good infection  prevention and control is essential to ensure the safety of the  patient undergoing any surgical procedure in the operating  theater. The surgical site infections (SSIs) constitute 20% of  the total hospital-acquired infections [4]. These infections  cause substantial patient mortality and morbidity and burden  healthcare systems with massive costs. Since these infec-  tions are primarily acquired during the operative procedure  when the wound is still open, stringent protocols need to be  followed at this point to minimize their onset.    R. K. Bali (&X)  Postgraduate Department of OMFS, DAV Dental college hospital,  Yamunanagar, Haryana, India    © The Association of Oral and Maxillofacial Surgeons of India 2021   To establish surgical protocols, it is important to understand  the basic concepts of sterilization, asepsis, and infection con-  trol. In this respect, the following terminologies are very  commonly used:   These agents are a by-product of certain microorganisms,  which either have the capacity to destroy or inhibit the  growth of other microorganisms at low concentrations.   A substance (or drug) capable of killing microorganisms or  inhibiting their growth, in particular, pathogenic microor-  ganisms. This is a general term used to encompass those  drugs that specifically act on certain types of microorgan-  isms, including antibacterial (antibiotics), antifungal, antivi-  ral, and antiprotozoal agents.    Antimicrobial Agent  Any agent synthetically or naturally obtained that can destroy  or attenuate the microorganisms.    Antisepsis  It is the process in which microbial agents on a living surface  are either killed or their growth is arrested.   These are the substances applied on the living tissues to  reduce the possibility of infection, sepsis, and putrefaction  by inhibiting the activity or growth of the microorganisms.    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1-15-1346-6_9    Aseptic Processing  It is defined as the processing and packaging of a sterile  product into sterilized containers followed by proper sealing  with a sterilized closure in a manner to control microbiologi-  cal recontamination.   It is an antimicrobial agent that has the capacity to destroy  both nonpathogenic and pathogenic organisms but may not  destroy bacteria in spore form.    Bacteriostatic  It is an antimicrobial agent that inhibits the growth of micro-  organisms but is not capable of killing them.    Bioburden  The occurrence of viable microorganisms on a surface or  object before the sterilization procedure.   A standardized test preparation of bacterial spores used to  demonstrate effective sterilizing conditions by providing a  defined resistance to a specific sterilization process.   These are agents or devices used to monitor or confirm the  attainment of one or more of the parameters required for a  satisfactory sterilization process or used in a specific test of  the sterilization equipment.    Chemisterilant  It is an agent, chemical in nature with properties that kills all  forms of microbial agents, including spores.    Cleaning  It is the process of removing all forms of foreign materials  (from objects using detergents & water, soaps, and enzymes)  by employing the mechanical action of washing or scrubbing  the object.    Contamination  It is the process of entry of microbial agents into tissues or  any aseptic environment.    Crossinfection  The spread of infection from one person, object or place to  another.   The process by which a person or a surface is made free from  all the agents that contaminate the surface and lead to the  spread of infections. [5]   It is a chemical agent with cleansing actions in dilute solu-  tions, which, on combining with impurities and dirt, make  them more soluble.    Disease  Disruption of the normal performance of the vital functions  of a plant or animal by an infection.   This is an agent, usually a chemical, applied on inanimate  objects that destroys microorganism in the vegetative form  but not the spores.    Chemical disinfectant agents are categorized into low level,  intermediate, and high level (depending on the product claims  and regulatory requirements in different parts of the world).    ¢ High-level disinfection (HLD): It is a process in which a  small number of spores or certain bacteria are killed by  the use of certain antimicrobial agents at a specific tem-  perature and appropriate concentration.   ¢ Intermediate-level disinfection (ILD): It is a process in  which vegetative forms of all microorganisms are destroyed  but affect the activity of spores of certain bacteria.   ¢ Low-level disinfection (LLD): It is a process in which vege-  tative forms of all microorganisms are destroyed having no  activity on spores of bacteria at very low concentrations.   Antimicrobial process to remove, destroy, or deactivate  microorganisms on surfaces or in liquids. Disinfection is  often considered as a reduction of the numbers and types of  viable microorganisms (or “bioburden”) but may not be  assumed to render the surface or liquid free from viable  microbial contamination (in contrast to sterilization).    Droplet Nuclei  These are those particles of 1-10 1m that are implicated in  the spread of airborne infections.    Fomites  Any inanimate object that is capable of absorbing or transmit-  ting infectious microorganisms from one person to the other.    Fumigation  The process of disinfecting or purifying an area or object  with the fumes of certain chemical agents.    Germicide  Agents that are designed to kill and destroy pathogenic  organisms on the surface of different things.   It is the process of invasion of the tissues by microorganisms  and their multiplication in the body of the host to produce  disease.    Microorganisms or Microbe  Microscopic organisms, which may exist in its single-celled  form or in a colony of cells.    Minimum Effective Concentration (MEC)  The lowest concentration of a chemical or product, used in a  specified process that achieves a claimed activity.    Minimum Recommended Concentration (MRC)  The lowest concentration of a chemical or product specified  by the equipment manufacturer to be used in a process.   The operating room or operating theater is a facility within a  hospital where surgical procedures are carried out in an asep-  tic environment.    Pathogen  A pathogen is a tiny living organism, such as a bacterium  or virus that is capable of producing disease in an  individual.    Resistance  It is the natural ability of the agent to oppose the effects of  any harmful agents.   Packaging that prevents the ingress of microorganisms fol-  lowing a sterilization process, thereby preserving the sterile  state.   Physical or chemical agent (or combination of agents) that  has sufficient microbicidal activity to achieve sterility under  defined conditions.   These are the reproductive forms of some microorganisms  that can survive harsh environmental factors and have the  capability of developing into new viable microbes.   Sterilization is a process that destroys or removes all micro-  bial life completely, including spores by means of certain  chemical or physical processes.   It is an organism that does not cause disease itself but which  spreads infection by conveying pathogens from one host to  another.   It is a pathogen’s ability to infect, sustain, or spread infection  in a living a host. Historical background of present day pro-  tocols is enumerated in Table 9.1.   Approximately 2—5% of all surgical patients tend to acquire  surgical site infections (SSIs) [4]. In developed & high-  income countries (HICs), SSIs are the second most common  cause of healthcare-associated infections [6], whereas in  Low- & Middle-Income Countries (LMICs) or underdevel-  oped & developing countries these infections are the most  common ones. Thus, to reduce the risk of surgical site infec-  tions, a more systematic approach has to be adopted, based  on proper knowledge regarding the status of the patient, type,  & time of the operation, personnel involved and the health  care facilities available during a surgical procedure. The  main pathogenic source of surgical site infections is  the endogenous flora (usually aerobic gram positive cocci) of  the patient present in the skin, the mucous membranes, or the  hollow viscera. The exogenous sources of infection include   Sushruta instructed operating team members to  clean and fumigate the operating theater with  vapors of certain disinfectants prior to all surgical  procedures   Paracelsus, called the father of medicine,  reformed pharmacopeia and introduced  compositions of lead, copper, sulfur, iron, and  mercury    « 1889  ¢ 1882 Robert Koch introduced the use of mercuric  bichloride as antiseptic agents and isolated the  bacilli of tuberculosis   Sterilization of instruments, hand washing, and  the wearing of masks, caps, gloves, and gowns  was introduced    members of the surgical team, environment of the operating  theater and tools, materials & instruments brought to the  sterile zones during the surgical procedure. Various strate-  gies employed to prevent or control the occurrence of surgi-  cal site infections include reducing the contamination by  microorganisms on the sterile surgical instruments as well as  the body of the patient, prophylactic preoperative antibiotic  coverage, carrying out the surgical procedure carefully,  proper handling of the operating room.   Surgical safety is of utmost importance in order to prevent  major and life-threatening complications leading to undue  loss of life and patient morbidity. Thus, a list of ten essential  objectives with a surgical safety checklist have been eluci-  dated by the WHO to be followed by all the personnel pres-  ent in the operating room to reduce the risk of such  complications [7] (Tables 9.2 and 9.3).   The operating room or operating theater is a facility within a  hospital where surgical procedures are carried out in an asep-  tic environment. Since the operating theater is a highly ster-  ile, aseptic, and restricted area in a hospital setting, it is    (1) The operating team must ensure that the correct surgical  procedure is to be carried out on the correct patient.   (2) The operating personnel should have adequate knowledge  regarding the anesthesia, its methods of administration as well  as its effects so that minimum pain is experienced by the  patient.   (3) The operating personnel should be well prepared for any  life-threatening conditions like loss of airway or respiratory  function.    (4) The operating team should be prepared for risk of high loss of  blood.   (5) The operating team should be well versed with the history of  the patient in order to prevent or induce any allergic or adverse  drug reactions that can cause a significant risk for the patient.   (6) Care must be taken to minimize the formation of surgical site  infections by using proper measures.   (7) Proper care must be taken to not leave any instrument or any  foreign material at the surgical site.   (8) All specimens should be carefully identified and secured for  further investigations.   (9) Proper communication must be present among the operating  team personnel for the safe conduct of the surgical procedure.   (10) A routine surveillance of the surgical volume, safety protocols,  capacities, and the outcomes must be carried out by all the  hospitals and the health care systems.    mandatory for all the personnel concerned to have a proper  understanding of the working of the operation theater abid-  ing by certain laws, regulations, and professional guidelines.  Integrated infection control in the operation theater is the key  to decreasing morbidity and mortality among the patients  undergoing surgery.   — Proper machines and equipment for monitoring the con-  dition of the patients during the surgeries    ¢ Location of the Operating Theater: The location of the  operation theater should be such that adequate natural  light and proper ventilation is present. For this, a two- or  three-story building away from the general hustle and  bustle of the hospital is preferred.   ¢ Operation rooms: The standard recommended size of the  operation theater is 6.5 m x 6.5 m x 3.5 m and can be  modified as per requirement   ¢ Doors and Windows: There should be separate entry and  exit doors. The width of the door should be approximately    ¢ Yes, and equipment /assistance available  Risk of >500 ml blood loss (7 ml/kg in children)   Confirm all team members have introduced  themselves by name and role   ¢ Surgeon reviews: What are the critical or  unexpected steps, operative duration,  anticipated blood loss   ¢ The instrument, sponge, and needle  counts are correct (or not applicable)    Surgeon, anesthesia professional and  nurse review the key concerns for  recovery and management of this patient    (including indicator results) been confirmed?  Are there equipment issues or any concerns?  Has antibiotic prophylaxis been given in the  last 60 min?  ¢ Yes / not applicable  Is essential imaging displayed  ¢ Yes/not applicable    1.2 to 1.5 m. Sliding doors are preferred than spring-loaded presence or absence of microorganisms, and the different pro-  doors in order to minimize the generation of the air cur- cedures to be carried out in each zone (Fig. 9.1).   Windows made from glass are preferred, which are to be 1. Protective zone: It includes    e The surface/flooring: The flooring must be such that it is ¢ Transferring passage for the materials, equipment, and    nonslippery, strong, & with minimum joints to decrease  the accumulation of dust and other tiny particulate matter  within it.    . Clean zone: Links the protective zone to the aseptic zone    Different Zones of Operation Theater Complex  There are four different zones observed in any operating room    — The sterilized materials are transported from a sterile area  to the operation theater on a covered cart, thus preventing    — Before entering the operation theater, all supplies/materi-  als must be removed from their shipping or transported    — All the blood-coated or soiled instruments/equipment must  be transported in a covered wrap or container from the oper-    — Proper ventilation should be checked regularly and the  filters should be changed as required.   — At the time of maintenance or inspection or observation  of any fault in the working of the operation theater, the  members of The Infection Control team should be  informed. The theater should be thoroughly examined by  the members of the team and appropriate measures must  be taken to maintain the infection control protocols. The  operation theater must only be functional after being care-  fully evaluated and cleared by the infection control team.   — Back-up facility for operation theater in all aspects should  be present in any setup to provide any uninterrupted ses-  sions at the time of maintenance or any fault observed.    Sterilization is the ultimate procedure in controlling the unde-  sired activities of microorganisms that are outside of the  human body. Its purpose in the operating field is to prevent  the spread of infectious disease, and in surgery, it primarily    relates to processing reusable instruments. Surgical instru-  ments are an integral part of surgical field and, being reusable,  have greater chances of spreading the microorganisms if any  of the reprocessing steps fails. Steps of reprocessing include  cleaning, repackaging, disinfection or sterilization, and reus-  ing. Cleaning, being the first step in the cycle of reprocessing,    ¢ Critical: An instrument that has a direct contact with sterile tissues  or vascular system [8]; such items are to be sterilized and made free  from all microorganisms. Examples are extraction forceps, scalpel  blades, bone chisels, periodontal scalers, surgical burs, needles  Semicritical: An instrument that does not usually penetrate the  sterile tissues but does come in contact with intact mucous  membrane. These items are made free from microorganisms by  high-level disinfection. Examples include endoscopes, amalgam  condensers, air/water syringe, impression trays, dental hand piece,  dental mirrors   Noncritical: An instrument that does not touch the patient directly  or come in contact with the intact skin only. These items may be  cleaned or disinfected by low-level disinfection. Examples include  light arm/handles, dental chair, dental X-ray equipment, chair side  computers, chair switches.    is the major step in the removal of any organic matter present  on the surface of the instruments. Any failure in the removal  of the visible soil at the initial stage can create a discrepancy  in the efficacy of the subsequent disinfection and sterilization  procedures. Sterilization is more effective a process than dis-  infection. The process of disinfection is carried out with the  use of various chemical agents. Chemical disinfecting agent  necessarily does not kill all microorganisms or spores present  on an inanimate object but instead reduces the number of  microorganisms to a level that is not harmful to health.  Depending on their potency against microbes, they are classi-  fied as High-, Intermediate-, or Low-level disinfectants.   The type of the sterilization procedures to be carried out  for an object depends upon the classification of the instru-  ments based according to the Spaulding Classification of the  medical devices, the type of material of which the object is  made of, the microorganisms to be present on the object, and  availability of the sterilization methods and equipment  (Table 9.4).    Various methods of decontamination include. upon the material of which they are made and the use they  perform.  e Physical cleaning. Manual cleaning is necessary when:  e Water purification e Cleaning of instruments by mechanical means is not  ¢ Ultrasonic cleaning possible  ¢ Disinfection ¢ Instruments to be cleaned are delicate in nature  e Antisepsis ¢ Objects to be cleaned have a narrow lumen (Fig. 9.3)  ¢ Sterilization 3. Soaking of instruments prior to cleaning:  There are times when cleaning alone cannot remove the  Processing of the clinical or surgical items is a two step debris present on the surface of the objects as the items  procedure. become highly soiled with foreign materials. For this, it is  A. Cleaning, being the first step, is the most essential one, sometimes necessary to soak instruments/objects prior to  which is succeeded either by Disinfection or cleaning. A container having a deeper base is filled with  Sterlization detergent & water and all the instruments are kept in it for  e Cleaning is the process of removing all the foreign 3-5 min. The solution prepared is agitated by shaking it  particles present on the surface of the object, which is vigorously. The cleaned instruments are now removed  accomplished by means of two main steps, i.e., clean- from the container and placed over a tray for air drying.    ing by friction to remove foreign particles and rinsing  away by fluids to remove the debris so cleaned.   e If the objects to be sterilized, remain soiled with for-  eign materials, the microorganisms will be trapped in  the organic matter and may interfere with the proper  sterilization or disinfection procedure. Therefore,  thorough cleaning should always precede the steril-  ization process.   e Cleaning may be manual or mechanical and is nor-  mally accomplished by the use of water, detergents,  and mechanical agents. Detergent is essential to dis-  solve proteins and oil that can reside on instruments  and equipment after use.   1. Mechanical cleaning  With the advancement in the sterilization equipment,  most units are automated and there is very less handling  of dirty equipment by the concerned staff. The equipment  to be processed is placed in trays and is ready for  washing.   ¢ Washing machine: It gives a cold rinse followed by a   hot wash at 71 °C for 2 min. This is followed by a  10-second hot rinse at 80-90 °C and then by dry heat  at 50-75 °C.   is extremely efficient in removing the debris. 0.44 W/  cm? of power is used to remove the debris by the pro-  cess of sonic waves produced. The solution used most  often to clean is an enzymatic presoak (protease for-  mula that dissolves protein).  2. Manual cleaning  It is an active method that is carried out by thoroughly  brushing the item with the help of a toothbrush under  water to prevent the release of aerosols. The brush should  be thoroughly cleaned after use and should be dried. The  cleaned items are then dried and made ready for the  proper sterilization procedure to be carried out depending Fig. 9.3 Manual Cleaning    B. Disinfection and Sterlization  ¢ Disinfection can be achieved by either thermal or chemical   due on the surface and is preferred more than chemical  disinfection procedures. The main indication of chemical  disinfectant use is the heat-sensitive objects. Chemical   (a) Most commonly used for heat-labile instruments/  objects (e.g., endoscopes) where single use is not cost  effective.   (b) Disinfectants used for this purpose are  ¢ Glutaraldehyde: 2% for 20 min.   e Hydrogen peroxide: 6%-—7.5% for 20-30 min.  ¢ Per acetic acid: 0.2-0.35% for 5 min.  ¢ Ortho-phthalaldehyde (OPA) for 5—12 min.   e Fresh disinfectant solution should be made each  day in a sterile container. If a previously prepared  solution is to be used, an indicator strip is dipped  in the solution to check for the effectiveness of the  solution.   e Place all items in the solution completely sub-  merged in the container.   e The container is covered and the instruments are  allowed to soak in for 20 min.   e Items disinfected are covered in a disinfected con-  tainer and used within a week.    Sterilization is a method by which an article, medium,  or surface is made free from all microbial invasions,  including spores. The main aim of sterilization of instru-  ments is proper delivery of sterilized instruments at the  operating field, thereby maintaining a sterile environ-  ment and reducing the spread of infections from one per-  son to another. Proper handling of the sterilized  instruments is done by appropriate wrapping and storage  of the instruments, thereby increasing the shelf life of the  sterilized instruments. The instruments should be bagged  or wrapped in a muslin cloth or clear pouches or paper  before and after the procedure and the wrapping should  be sealed with tape. No pin, staple, or any paper clips are  to be applied on the wrapping as these may create small  openings, which may allow entry of microorganisms,  thereby hampering the process of sterilization.  Sterilization is accomplished by:    This is the most simple and efficient means of ster-  ilizing instruments. It is also commonly called  steam sterilizing or autoclaving.   — Temperature 121 °C (250 °F) at a pressure of 15  pounds per square inch (psi) for 15 min.   — Temperature 134 °C (270 °F) at a pressure of  30 psi for 3 min. This process termed “flash ster-  ilization” has practical use in the operating room  where fast sterilization of instruments may be  necessary.   — The main aim of bagging or wrapping the instru-  ments prior to sterilization procedure decreases  the chances of contamination of the items after  the sterilization procedure is complete.   — Two-layer wrapping of objects should be pre-  ferred and the materials used for this can be cot-  ton fabric or muslin, paper, newspaper (Fig. 9.4).   the procedure is determined by assessing the bio-  logical, mechanical, and chemical parameters.   biological indicators (BIs) that directly inhibit the  growth of highly resistant microorganisms, rather  than merely testing the physical and chemical con-  ditions necessary for sterilization. Since the spores  present in a biological indicator are in a much  higher number and are highly resistant by nature  compared to the other and common microorgan-   Place the instrument or  other item in the centre of  the top wrapper. It should  be positioned so that the  points (not the flat edges)  are at the top, bottom &  sides.   Fold the bottom section of  the top wrapper to the  center, and fold back the  point.   Fold the left section to the  center, and fold back the  point.   Fold the right section to the  center, and fold back the  point.   Fold the top section to the  center, and fold back the  point.   Fold the bottom section of  the bottom wrapper to the  center, and fold back the  point.   Fold the left section to the  center, and fold back the  point.   Fold the right section to the  center, and fold back the  point.   Fold the top section to the  center, and fold back the  point.    vated biological indicator indicates that the other  microorganisms are killed depicting an effective  sterilization procedure. A control BI, from the same  lot as the test indicator and not processed through  the sterilizer, should be incubated with the test BI;  the control BI should yield positive results for bac-  terial growth.    observing the gauges or display for the pressure on  the sterilization equipment for each set of items to  be sterilized come under the mechanical monitoring  of sterilization.   Certain chemical agents are used to check the efficacy  of the sterilization procedure being carried out by  undergoing chemical changes in their properties on    being exposed to the sterilizing conditions. These  chemical agents are called the chemical indicators  and these include TST (Time-Steam-Temperature)  Strip. This TST strip is to be placed in a big surgical  wire basket and when exposed to a critical time,  steam, and temperature it undergoes a change in color  from yellow to dark blue indicating complete steril-  ization procedure. Another strip is to be used when  double-layered packing of instruments in crepe paper  is done to assess the parameters inside the sterilizer.   — There must be a separate area for storing of the  sterile instruments and single-use (disposable)  products.   — The storing of the bagged sterilizer objects can be  depicted either by the date on which they are ster-  ilized or the procedure for which it is to be used or  an event causing it to become contaminated.   — All the packed items must be carefully inspected  before using to verify the integrity of the outer cov-  ering and the condition of the packing (dry/wet).   — Once the packing is assessed and if any breach is  seen in the packing, the wrapping should be  replaced and the instruments again sent for the  sterilization procedure.   of the sterilization process, the efficacy of the process,  and the handling of the sterilized instruments.   ered sterilized and safe for use. However, the con-  taminated instruments are preferred processing and  sterilization prior to every procedure.    It is used for sterilization of heat-labile and  moisture-sensitive items, supplies, and equipment.  The operating cycle ranges from 2—24 h and it is a  relatively expensive process.   It can be used for glass, paper surfaces, clothing, plas-  tics and metals, food stuffs, and dental equipment.   It is unsuitable for fumigating rooms because of its  explosive property.    It may be used for sterilization of instruments with  cutting surfaces.   No corrosion occurs with this method of sterilization.  Dry heat sterilization, which usually occurs con-  sists of hot air oven has typical cycles of 1 h at  171 °C or 2 hat 160 °C.   Air is a poor conductor of heat and requires a long  time for getting the instruments effectively sterilized.    This is also a choice for some limited circumstances.  Some instruments cannot be subjected to high tem-  peratures and in a field environment chemical ster-  ilization may have to be used.   The disinfectant must remain in contact with the  surface for appropriate time.    Hand hygiene by operation theater persons is the most  efficient way to reduce the risk of spread of infections.   Surgical hand wash or surgical hand rub should be car-  ried out prior to the procedure in order to decrease the  residing flora of the hand.   The temperature of water is to be adjusted so that it  is slightly warm. Hands and forearms are to be  washed 5 cm above the level of the elbows to  remove any particles of dirt.   Before performing the first scrub of the day, a nail  cleaner is used to clean the fingernails and the nail  beds.   The nails should be cut short and no nail polish  should be used.   Antimicrobial agent is to be applied on the hands and  in circular motion; lathering should begin at the finger  tips of one hand and between the fingers, continuing  from the fingertip to 5 cm above the elbow. The same  process is to be repeated for other arm and hand.   The rubbing should be done for a period of 3—5 min.  Each arm is to be washed separtely at the level of  elbow, starting at the fingertips.   One side of the sterile towel is used to dry the fin-  gertips up to the elbow of one hand and the other  side is used to dry the same on the other hand.    3. Barrier techniques:  Barrier techniques are useful where the chances of spread  of infection are higher.  (a) Head Cover    Prior or during the procedure, all facial and head hair  should be tied properly and covered by means of head  covers. Ideally head covers should be disposable and  made of soft, nonporous cloth like material. If one has  long hair, the hair should be tied in a bun. In situations  where tying a bun is not possible, use of helmets or  hoods or headgears is of utmost significance.    — Tuberculosis is one of the most common infec-  tious diseases that can spread through airborne  route,   — The main aim of using a mask is the prevention of  transmission of infectious agents from the mem-  ber of the operating team to the patient’s wounds  and also protecting the operating team members  from the splashes and sprays from the patient.   — The masks, which are disposable in nature, are  always preferred.   — The mask should be made of synthetic fibers, must  be flat with two or three pleats that expand to cover  the area up to chin, and should have filters of poly-  propylene or polyester (Fig. 9.5).   Scrub suits and cover gowns  These are the pair of garments to be worn over, or  instead of regular clothing of the persons involved in the  surgical procedures to protect the transmission of any  infectious agent present on the regular clothing from the  operating personnel to the patient or any other person-  nel. These should have a simple design, should be com-  fortable, should be easy to clean and wash, should be  economical, easily replicable if damaged and should  have minimal place for the contaminants to hide.   These are a loose pair of clothing to be worn over the   scrub suits or cover gowns at the time of the surgery   to protect both the patient and the operating personnel  from transfer of microorganisms, blood or body flu-  ids, and another particulate matter.   e Dry the hands completely and hold the gown in  such a manner that it is at the least risk of  contamination.   Slip arms into the sleeves through the armholes,  keeping at the shoulder level and away from the  body.   The circulating person must pull the gown over the  shoulders touching only inside of the gown.   All the belts and loops are to be tied securely  (Fig. 9.6).    They help to protect the operator from infection by  bacteria and viruses from patient’s blood. Gloving is  essential to protect both the surgeon and the patient  from blood-borne viruses and to prevent wound from  becoming contaminated with the surgeon’s skin flora.  The “open gloving” and “closed gloving” technique  of donning the gloves should be employed for wear-  ing gloves.   — Inspect the outer covering for the integrity.  Open the first nonsterile packaging by peeling  it completely off the heat seal exposing the  inner sterile wrapper, but without touching it.   — The inner sterile packing is kept on a dry area,  without touching the outer surface. Open the  package and fold it toward the bottom so as to  unfold the paper and keep it open.   — By using index finger and thumb of one hand,  the folded edge of the glove is grasped.   — The second glove is picked by using the cuff of  the other glove and sliding the fingers of the  gloved hand into it.    1. Dry hands 2. Pick up gown 3. Let gown unfold    In a single movement, slip the second glove on  to the ungloved hand while avoiding any con-  tact/resting of the gloved hand on surfaces  other than the glove to be donned (Fig. 9.7).    If the cuffs are not fitting, a tuck is taken in  each gown.   The circulating person should open the outer  covering of the glove and should flip them onto  the sterile field.   The inner packing containing the gloves is  opened carefully and the glove is picked up by  the folded cuff edge with the hand covered by  the sleeve.   The glove is placed on the sleeve of the oppo-  site gown, the palm facing downwards, with the  fingers of the glove pointing toward the  shoulder.   The gloves should be placed in such a manner  that the rolled cuff edge of the gloves connects    the sleeve to the gown cuff. Bottom cuffed and  rolled edge of the glove is grasped at the bot-  tom with the index finger and thumb.   — With the opposite hand, the outermost edge of  the cuff of the gloves is held taking care that the  uncovered fingers are not exposed by it.   — By using the opposite hand covered with sleeve,  both the cuffs of the sleeve and the glove are  seamed and the glove is pulled over the hand.   — The same procedure is to be followed for the  other hand. The fingers are adjusted to properly  fit in the glove (Fig. 9.8).   ¢ Towel drapes, which are used for squaring off the oper-  ative site, wrapping syringes & small instruments, and    drying of the hands. These must be more resistant to  water and must be made of cotton compared to linen.   e Lap sheets are used for covering the patient. They are  large and long, usually made of lightweight cotton, and  provide limited protection and coverage to the patients  or staff or the surface areas.   e Site drapes are made of cotton and have a circular  opening in the center that is placed over the prepared  operative site. These drapes are primarily intended for  use with minor surgical procedures (Fig. 9.9).    A widely used classification of surgical wounds is based on  an estimate of likelihood of bacterial contamination of the  operative site. In 1964 [9], National Academy of Sciences/  National Research Council defined five general classes of  operations:   3. Clean-Contaminated: Oral cavity, gastrointestinal, or  respiratory tract entered without significant spillage,  entrance of genitourinary tract in presence of infected  urine, entrance of biliary tract in presence of infected bile  or minor break in technique.   4. Contaminated: Major break in operative techniques (e.g.,  surgical entrance of unprepared bowel without gross  spillage of bowel contents); acute bacterial inflammation  without pus; fresh, traumatic wound from a relatively  clean source.   5. Dirty: Presence of pus or perforated viscous (prior to  operation), old traumatic wound, or traumatic wound  from a dirty source.    Currently, this classification has been condensed into four groups for  general use, without a subdivision of the clean category and in the  modified form it is categorized into four categories [10]  1. Clean sites (wounds):  ¢ Elective (not urgent or emergency).  ¢ Primary closed.  ¢ No acute inflammation or transection of tracheobronchial,  biliary, gastrointestinal, oropharyngeal tracts.  ¢ No technique breaks.  2. Clean-contaminated sites (wounds):  ¢ Emergency or urgent cases that are otherwise “clean.”  ¢ Elective procedures.  ¢ Reoperation via “clean incision” within 7 days.  ¢ Blunt trauma, intact skin, and negative exploration.  3. Contaminated sites (wounds):  ¢ Acute nonpurulent inflammation.  ¢ Major technique break or major spill from hollow organs.  ¢ Entrance of genitourinary or biliary tracts in presence of  infected urine or bile, respectively.  ¢ Penetrating trauma less than 4 h old.  ¢ Chronic open wounds to be grafted or covered.  4. Dirty sites (wounds):  ¢ Purulence or abscess.  ¢ Preoperative perforation of tracheobronchial, biliary,  gastrointestinal, oropharyngeal tracts.  ¢ Penetrating trauma more than 4 h old.    “Cut Well, Sew Well, Heal Well” is an axiom favored by sur-  geons but is not always destined to be true. Altemeir and  Culbertson (1965) [11] depicted that the risk of infection  varies:    (a) The risk of infections is proportional directly to the dose  of contamination to bacteria.   (b) The microbial virulence is also directly proportional to  the risk of infections.   (c) The patient’s ability to control and inhibit the resistance  is proportional inversely. [12]    These factors interact in a complex way to fasten the  development of infection. Since the days of Altemeier, clini-  cal and epidemiologic studies have identified the risk factors  that affect the rate of postoperative surgical site infection.  This can be best explained by the classical epidemiological  triangular model, i.e., model of interaction between agent  host and environment resulting in disease (Fig. 9.10).   The risk of postoperative wound infection also depends  on the patient factors, pre and intraoperative factors  (Table 9.5). Haley et al. (1985), in the Study of the Efficacy  of Nosocomial Infection Control “(SENIC),* [13] identified  four independent and additive risk factors for postoperative  wound infection. These factors are operation on the abdo-  men, operation lasting for more than 2 h, contaminated or  dirty wounds (NRC CLASSIFICATION), and the presence  of more than three discharge diagnoses.    e Hair removal should not be performed on routine basis to    decrease the risk of surgical site infection. Razors should  not be used to remove the hair as they increase the chances    of infections [14]. Electric clippers with disposable heads  must be used only for removing hair few hours prior to the  surgical procedure.   e The treatment protocols and the condition of the patient  during the hospital stay make them more prone to the  spread of infections.   ¢ Wound dressings: Cover surgical incisions with an appro-  priate interactive dressing at the end of the operation.   Hospital infections occur as a result of a variety of microor-  ganisms. The microorganisms causing the disease may be  divided into the following categories:    1. Conventional pathogens are the ones that are capable of  causing a disease in normal and healthy person.   2. Conditional pathogens are the ones that initiate the onset  of a disease in persons who have decreased immunologi-  cal response to infection or when implanted directly into  sterile area or tissues.   3. Opportunistic pathogens are the ones that normally do not  harm its host but can cause disease when the host’s resis-  tance to the microorganisms is low.    During the stay in a hospital, the patient comes in contact  with various kinds of microbial agents (such as viruses,  fungi, parasites, and bacteria), which are the main cause of  the occurrence of infections in a patient. This exposure is not  the only reason for the development of hospital-acquired  infections. The other possible reasons are the host’s natural  defense mechanisms (healthy/compromised/immunosup-  pressed), conditions present in a hospital environment,  microbiology of the microbial agents (characteristic fea-  tures), infective material present on the microbial agent,  resistance to the antimicrobial agents, and other factors. The  hospital-based infections may be a result of the spread of    infection from one person to the other or by the residential  flora of the patient or from any contaminated sources or from  sources of the external origin (e.g., airborne diseases).   Following are the factors that are the main sources of  spread of hospital-based infections:   Patient factors that lead to the occurrence of infection are  age, host’s immune response, presence of any disease, and  interventions, which either help in diagnosing or treating any  condition. Patients, either infant or older individuals, are at a  higher risk of acquiring infections. Patients having a com-  promised immune system, undernourished, having some  underlying chronic disease (AIDS, leukemia, malignant  tumors, renal failure, diabetes mellitus, etc.), undergoing  irradiation therapy, all at the highest risk of being infected by  the hospital-based infections. Certain processes like cathe-  terization, biopsy, intubations, etc. make the patient more  vulnerable to these infections.   Resistance of bacteria to antimicrobial agents is seen with  the prolonged or prophylactic use of these agents. The  microbial agents present normally in the human flora have  both sensitive and resistant strains. Some antimicrobial  agents have their action on sensitive strains by suppressing  their activity, whereas the resistant strains are still active.  These active resistant strains are the major cause of the  development of resistance against the antimicrobial agents.  Examples of resistant microbial agents are Multiresistant  Klebsiella, strains of pneumococci, staphylococci, etc. In  low-income or middle-income countries, this is the major  problem faced due to unavailability and unaffordability of  the better drugs.   The possible explanation for increased infection rates in  summer is the relatively high environmental temperature  leading to humid climate, resulting in excessive sweating. In  addition, excessive sweating results in the displacement of  bacteria lodged in skin appendages to the surface.   The use of electric cautery for cutting and coagulation dur-  ing surgery causes more inflammation; more necrosis and  abscess than the conventional use of scalpel and thus it  increases the susceptibility of tissue for infection. Soballe  et al [15], in their experimental study, found that electric  cautery lowers the contamination threshold for infection of  laparotomies and concluded that electric coagulation cur-  rent should be used only when the need for meticulous  hemostasis outweighs the considerably increases risk of  infection.   There is a direct correlation between the infection rate and  time taken for the procedure. This may be the result of the  more complicated operations being of longer duration,  increased wound contamination from airborne bacteria,  increased damage to the tissues due to large exposure of the  wound, and increased manipulation; moreover, local resis-  tance of tissue is reduced due to drying.    9.9.1.7 Spread of Infection  The microbial agents are spread by different ways in a health  care setup. The different ways with which the agents can  spread are contacting, droplets, airborne route, via vehicle,  and vector-borne (Fig. 9.11).   Sources of the infectious agents are either external, i.e.,  from one person to the other, or from the hospital’s environ-  ment; or internal, i.e., within the patient himself.    ¢ Contacting is the most frequent and important route of  spread of infections. It is further of two types, 1.e.    — Direct contacting is the spread of infection directly  from the person infected from the infection to other  normal who has increased chances of being infected. It  also occurs among two patients where one acts the  source of microbial agents and the other becomes the  one to receive the infection.   e Indirect contacting is the spread of infection indirectly  from one person/object to the other. It involves contact of   lets from the source person mainly during coughing,  sneezing, and talking, and during the performance of cer-   the other susceptible person.  ¢ Airborne transmission results from spreading of small  particulate matter (approximately 5 pm or smaller in size)   through the air, which remain suspended in the air for a    these particles. The main diseases to be spread via the air-  borne route are Tuberculosis, Influenza, Common cold,  etc.  ¢ Vehicle spread is the spread of infectious microbial agents  to the individuals by means of contaminated items such as  food, water, medications, devices, and equipment.  Vector-borne transmission occurs when vectors such as  mosquitoes, flies, rats, and other vermin transmit  microorganisms.    The occupational risk of acquiring viral diseases has been  well known in Maxillofacial Surgery [16]. The WHO  announced the Corona virus pandemic also known as  COVID-19 as a public health emergency of international  concern on January 30, 2020.   Coronaviruses are RNA viruses infecting many species of  animals including humans, name coronavirus was derived  from corona meaning crown like because of the morphology  observed for these viruses in the electron microscope. This  family of viruses includes Middle East Respiratory Syndrome  (MERS-CoV), Severe Acute Respiratory Syndrome (SARS-  CoV), and novel Coronavirus (n CoV).   Coronavirus is enveloped having round, spherical, or  sometimes pleomorphic structure, with size ranging from 80  to 120 nm in diameter, containing a positive-strand RNA. The  virus is made up of lipid bilayer envelop, membrane protein,  and nucleocapsid, these structures also protect the virus  when the virus is outside the host cell. The lipid bilayer  forms the viral envelop which anchors the membrane pro-  tein, envelop protein, and the spike protein. The spike protein  (S-protein) is responsible for the crown-like structure of the  coronavirus as it forms the protrusions from the surface  which bind to the host cells.    Human to human transmission is due to respiratory droplet  transmission and contact transmission. Spread occurs  through coughing, sneezing, spitting, contacting the body  fluids of the infected patient. The COVID-19 can remain  infectious on inanimate surfaces from 2 h to 9 days, depend-  ing on the humidity, temperature, surface type, and viral load  [17]. It has become an occupational threat to health care pro-  viders worldwide.   Some of the known routes of spread of infection to health  care providers are:    Aerosols generating procedures (AGP) create widespread  environmental contamination and therefore pose a greater  risk of transmission of infection to healthcare workers. Oral  and maxillofacial surgeons are particularly vulnerable to this  transmissible disease by way of the droplet or aerosol trans-  mission due to the area of work and the type of instrumenta-  tion [18].   The incubation period is long and unpredictable ranging  from 0 to 27 days with a mean of 6.4 days. Recent studies have  shown that asymptomatic patients and those within the incu-  bation period are also potential spreaders of the disease [19].    Symptoms may range from mild symptoms to severe respira-  tory distress and some patients may be asymptomatic.    « Common symptoms may include fever, cough, fatigue,  shortness of breath, loss of taste, and smell.   ¢ Less common symptoms may include myalgia, headache  sore throat, and chills.   ¢ Rare symptoms may include nausea, vomiting, nasal con-  gestion, diarrhea, palpitation, and chest congestion.    ¢ Chest X-ray may show findings that of atypical pneumo-  nia showing bilateral consolidations in lateral lower lobes,  bronchovascular thickening.   ¢ Chest CT ground-glass opacity and areas of consolida-  tion laterally.    The real time polymerase chain reaction (RT-PCR) of respi-  ratory secretions from bronchoalveolar lavage, endotracheal  aspirate, and nasopharyngeal or oropharyngeal swab is the  definitive test.   Other laboratory findings include lymphopenia, increased  prothrombin time, and mildly raised CRP and ESR.    COVID 19 has shifted the focus on teleconsulting which  includes tele screening, telemedicine, and _ triage.  Telemedicine should be practiced whenever possible to  decrease the footfall.   Thorough history should be obtained from the patient  regarding COVID 19 illness and elective procedures should  be postponed and only emergent conditions should be taken  up for surgery.   Patient should be called on the basis of appointments,  time between two appointments should be sufficient enough  to perform all necessary sanitization measures and ensure  minimal patient to patient overlap. In the waiting area, post-  ers should be displayed to encourage hand hygiene and the  wearing of masks and the area should be well ventilated. A  minimum of 2 m distance should be maintained between the  individuals.   Extraoral radiographs should be preferred as an alterna-  tive to intraoral periapical radiographs.   In the operatory there should be minimum personnel  present, Air Conditioners should be avoided, doors and  windows are advised to be kept open. The operating room  should be spacious with adjoining two rooms for donning  and doffing of the PPE’s. No touch sensor-based sanitizer  dispenser should be installed at the entry and exit of OR  [20].   All the surfaces of equipment like OR table, motor drills  etc., should be covered with plastic sheets and sheets to be  changed after every patient.   OT’s should be equipped with HEPA filter (0.1 micron  efficiency) and high frequency of air changes (ideally 25 per  hour) should be ensured to reduce the viral load [20].   High-volume suctions should be used with one-third of  suction jars prefilled with povidone-iodine solution.   The Povidone Iodine solution has been shown to have sig-  nificant viricidal activity up to 3 h and it has been advised to  coat the oral cavity and nasal passages of both the patient and  the operating team before the surgery [21, 22].   Fogger machines with 0.5% sodium hypochlorite can be  used for sterilization of dental chairs, tables, doors, door-  knob, etc. [20]. One-minute contact of the chemical ensures  viral kill.    e Masks including three-ply surgical masks, N95, N99  (FFP3), and the Powered air-purifying respirators  (PAPR’s) provide viral filtration in the increasing order. It  is important to mention that N95 masks were not found to  be adequate to prevent transmission in Chinese surgeons    and PAPR’s had to be used to prevent transmission from  COVID patients [23].   ¢ Triple protection gowns and face shield protect the sur-  geon from exposure to any kind of infected aerosols, body  fluids of the patient. Disposable gowns are made of non-  woven material and protect from liquid penetration.  Personal protective equipment like basic kit 45 GSM,  medium kit 70 GSM for surgery, and advance kit for ICU  180 GSM are recommended to be worn [20].    ¢ Surgery on COVID patient should be performed in a neg-  ative pressure theater or in airborne infection isolation   ¢ The surgeon should enter the theater after 20 min follow-  ing intubation with complete PPE to minimize the expo-   sure to aerosols [23].  ¢ Scalpels should be preferred over cautery.  ¢ Use of high-power drills, oscillating saw, and forceful   As the COVID-19 situation is a dynamic evolving one  and there is no definitive treatment available proper planning  and implementation of infection control protocols are key to  preventing transmission of the disease in the Maxillofacial  settings.    9.11 Control of Nosocomial Infections  CDC elucidated certain guidelines to check the nosocomial  infections in the Study on efficacy of nosocomial infection  control (SENIC). These guidelines have decreased the emer-  gence of hospital-acquired infections by a greater number.  However, any breach in the infection control procedures can  lead to spread of such infections.   Certain conditions leading to improper infection control  and spread of such infections are:    1. Improper sterilization and disinfection procedures.  2. Presence of contaminants in the food or water   5. Insufficient knowledge of Infection control principles and  practices among the staff.   6. Antibiotic abuse both in the community and in the  hospital.    Following are the steps that can be taken by the staff in a  hospital setup to prevent the spread of such infections:    e Isolation rooms for persons suffering from contagious  diseases such as COVID 19 and tuberculosis.   e The wound dressings should be changed at an appropriate  time with the use of proper agents.   e The antimicrobial agents should be carefully used.  Prolonged use should be avoided whenever possible to  avoid the emergence of the resistance.    Preventing and controlling infections is the key factor in  improving care and ensuring safety of both the patient  and the health care worker. Infection control addresses  factors related to the spread of infections within the  operation theater complex (whether patient-to-patient,  from patients to staff and from staff to patient, or among  staff), including prevention (via hand hygiene/hand  washing, cleaning/disinfection/sterilization, vaccination,  monitoring).   Integrated infection control in the operation theater has  various aspects, ranging from its designing ,environmental  cleaning , management of biomedical waste and adherence  to theatre attire. Use of Personal Protective Equipment (PPE)  including gloves, gowns, face masks ,respirators and full  face visors are essential to minimize risks of occupational  infections. Whether in developed or developing country,  where resources are limited, thorough knowledge about the  principles of infection control and a little ingenuity will suf-  fice to solve the problem of hospital-acquired infections.   Surgical site infections are a result of microbial invasion  in a sterile atmosphere. The main sources of microbial    invasion in the operating theater include the atmosphere of  the operating theater, the medical and the paramedical staff  present at the time of the procedure, surgical instruments,  and the patient at times also. Proper designing of operation  theater, appropriate microbiological monitoring, proper  sterilization, and strict adherence to barrier techniques  form the basis to prevent infections in an operating  environment.    1. Weiser TG, Regenbogen SE, Thompson KD, Haynes AB, Lipsitz  SR, Berry WR, Gawande AA. An estimation of the global volume  of surgery: a modelling strategy based on available data. Lancet.  2008 Jul 12;372(9633):139-44.   2. Weiser TG, Haynes AB, Molina G, Lipsitz SR, Esquivel MM,  Uribe-Leitz T, Fu R, Azad T, Chao TE, Berry WR, Gawande  AA. Size and distribution of the global volume of surgery in 2012.  Bull World Health Organ. 2016 Mar 1;94(3):201.   3. Bali R, Sharma P, Nagrath S, Gupta P. Microbial isolations from  maxillofacial operation theatre and its correlation to fumigation in a  teaching hospital in India. Journal of maxillofacial and oral surgery.  2014 Jun 1;13(2):128-32.   4. de Lissovoy G, Fraeman K, Hutchins V, Murphy D, Song D,  Vaughn BB. Surgical site infection: incidence and impact on hos-  pital utilization and treatment costs. Am J Infect Control. 2009 Jun  1;37(5):387-97.   5. Block SS. Definition of terms. Disinfection, sterilization, and pres-  ervation. Philadelphia: Lippincott Williams & Wilkins. 2001:19-28.   6. Bratzler DW, Houck PM, Workgroup SI. Antimicrobial pro-  phylaxis for surgery: an advisory statement from the National  Surgical Infection Prevention Project. Am J Surg. 2005 Apr  1;189(4):395—404.   7. Safety WP, World Health Organization. WHO guidelines for safe  surgery: 2009: safe surgery saves lives. Geneva: World Health  Organization; 2009.   8. Petersen BT, Chennat J, Cohen J, Cotton PB, Greenwald DA,  Kowalski TE, Krinsky ML, Park WG, Pike IM, Romagnuolo  J, Rutala WA. Multisociety guideline on reprocessing flex-  ible gastrointestinal endoscopes: 2011. Gastrointest Endosc.  2011;73(6):1075-84.   9. B’erard F. Postoperative wound infections: the influence of ultra-  violet irradiation of the operating room and of various other factors.  Ann Surg. 1964;160(1): 1-92.   10. Knight R, Charbonneau P, Ratzer E, Zeren F, Haun W, Clark  J. Prophylactic antibiotics are not indicated in clean general surgery  cases. Am J Surg. 2001 Dec 1;182(6):682-6.   11. Altemeier WA, Culbertson WR, Hummel RP. Surgical consider-  ations of endogenous infections—sources, types, and methods of  control. Surg Clin N Am. 1968 Feb 1;48(1):227-40.   12. Cheng H, Chen BP, Soleas IM, Ferko NC, Cameron CG, Hinoul  P. Prolonged operative duration increases risk of surgical site infec-  tions: a systematic review. Surg Infect. 2017 Aug 1;18(6):722-35.   13. Haley RW, Culver DH, Morgan WM, White JW, Emori TG, Hooton  TM. Identifying patients at high risk of surgical wound infection: a  simple multivariate index of patient susceptibility and wound con-  tamination. Am J Epidemiol. 1985;121(2):206-15.   14. Edmiston CE, Lee CJ, Krepel CJ, Spencer M, Leaper D, Brown  KR, Lewis BD, Rossi PJ, Malinowski MJ, Seabrook GR. Evidence  for a standardized preadmission showering regimen to achieve  maximal antiseptic skin surface concentrations of chlorhexi-    dine gluconate, 4%, in surgical patients. JAMA Surg. 2015 Nov  1;150(11):1027-33.   Soballe PW, Nimbkar NV, Hayward I, Nielsen TB, Drucker  WR. Electric cautery lowers the contamination threshold for infec-  tion of laparotomies. Am J Surg. 1998 Apr;175(4):263-6.   Bali R, Sharma P, Garg A. Incidence and patterns of needlestick  injuries during Intermaxillary fixation. Br J Oral Maxillofac Surg.  2011;49:221-4.   Kampf G, Todt D, Pfaender S, Steinmann E. Persistence of coro-  naviruses on inanimate surfaces and their inactivation with biocidal  agents. J Hosp Infect. 2020;104(3):246—-51.   Bali RK, Chaudhry K. Maxillofacial surgery and COVID-19, The  pandemic!! J Maxillofac Oral Surg. 2020;19(2):159-61.   Meng L, Hua F, Bian Z. Coronavirus disease 2019 (COVID-19):  Emerging and future challenges for dental and oral medicine. J  Dent Res. 2020;99(5):48 1-7.   Datarkar A, Purohit S, Tayal S, Bhawalkar . Operating room pro-  tocols in OMFS during Corona virus (Covid-19) pandemic. J  Maxillofac Oral Surg. 2020;19(3):327-31.    Eggers M, Koburger-Janssen T, Eickmann M, Zorn J. In vitro bac-  tericidal and virucidal efficacy of povidone-iodine gargle/mouth-  wash against respiratory and oral tract pathogens. Infect Dis Ther.  2018;7:249-59.   Kirk-Bayley J, Challacombe S, Sunkaraneni V, Combes J. The use  of povidone iodine nasal spray and mouthwash during the current  COVID-19 pandemic may protect healthcare workers and reduce  cross infection. Br Dent J. 2020;228(12):902.  https://aocmf3.aofoundation.org/#o=News %20Date%20  Facet,Descending. Accessed 30 Mar 2020    Open Access This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.  org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropri-  ate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.   The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in  a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.    The human fascination—and sometimes infatuation—with  chemicals that alter biological function is ancient and results  from long experience with, and dependence on, plants. Many  plants produce harmful compounds for defense that animals  have learned to avoid and humans to exploit [1]   With phenomenal increase in the knowledge about mecha-  nism of action of chemical compounds and rapid introduc-  tion of new drugs, pharmacology—the science of drugs—has  become increasingly important to all health professionals.  Practice of maxillofacial surgery utilizes drugs either as pri-  mary treatment modality or as a facilitator of surgical proce-  dures. A detailed description of the pharmacodynamics &  pharmacokinetics of these drugs is beyond the scope of this  chapter. The readers are encouraged to refer to the standard  textbooks of pharmacology for the same.    Infections caused by microorganisms have threatened human  life since time immemorial. Some of the organisms had the  potential to spread from one infected person to another at an  alarming rate causing worldwide pandemics and epidemics.  With the discovery of the first antibiotic, “the magic bul-  let’”—Penicillin, patients could effectively be cured of many  life- threatening infections [2].   Antimicrobial agents are of the few classes of drugs that  effectively treat the etiology of conditions and not simply  alleviate the symptoms of the diseases.    L. P. Rao (4)  Department of craniomaxillofacial surgery, Aster Medcity,  Kochi, Kerala, India    © The Association of Oral and Maxillofacial Surgeons of India 2021    The term antibiotic was first used by Selman Waksman et al.  to describe any substance produced by a microorganism that  is antagonistic to the growth of other microorganisms in high  dilution [3]. This definition excluded substances like gastric  juices and hydrogen peroxide that kill bacteria but are not  produced by microorganisms. It also excluded synthetic anti-  bacterial compounds like the sulfonamides. In current usage,  however, the term “antibiotic” is applied to any medication  that kills bacteria or inhibits their growth, regardless of  whether that medication is produced by a microorganism or  not.    The antibiotics have been classified in many ways, based on  their chemical nature, mechanism of action, type of organ-  isms against which primarily active spectrum of activity, etc.  (Table 10.1). The antibiotics exert their remarkably specific  action on the microorganisms, sparing the host, due to their  selectivity for target components, which are either absent or  not very important in humans. Among these targets are bac-  terial and fungal cell wall synthesizing enzymes, the bacte-  rial ribosome, the enzymes required for nucleotide synthesis  and DNA replication, etc.    The infectious diseases associated with the oral and maxil-  lofacial region have unique microbiological features because  of the abundance and variety of microorganisms in this  region. The normal flora of the oral cavity consists of up to  10'' bacteria per gram of tissue, with anaerobic bacteria pre-  dominating [4]. Although the subtypes and proportions of  organisms differ, the general pattern of the indigenous    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1-15-1346-6_10    Table 10.1 Different classes of antibiotics—based on their chemical structure and mechanism of actions   (b) Cephalosporins  (a) Sulfanilamide  (b) Sulfadiazine  (c) Sulfizoxazole  (a) Streptomycin  (b) Neomycin   (c) Trovafloxacin  (a) Pristinamycin lA  (b) Pristinamycin II A  (a) Linezolid    Streptogramins - two groups of antibiotics  that act synergistically  Oxazolidinones—potent last-resort drugs    microflora is similar in healthy individuals. However, sys-  temic diseases and concurrent use of medications result in  the presence of unusual organisms as part of the normal  flora and an increase in diseases caused by normal organ-  isms that usually are considered to have low pathogenicity.  Usually, the microorganisms are held in check by the body’s  defense mechanisms. When these mechanisms are impaired,  infection may result from an otherwise minor bacterial  exposure.   The pathobiology of mixed odontogenic infection is rela-  tively clear. The early cellulitis is the result of streptococci,  the moderate-to-severe infection is caused by a combination  of aerobic and anaerobic bacteria, and the well- circum-  scribed chronic abscess is caused primarily by anaerobic  bacilli alone [5]. A complex mix of strict anaerobes and fac-  ultative anaerobes account for most of the odontogenic infec-  tions. Empirical antibiotic choices can be made in this  situation where the microbiological pattern is well estab-  lished (Table 10.2).   Inhibit bacterial protein synthesis Bactericidal  Inhibit bacterial protein synthesis Bacteriostatic  Inhibit bacterial protein synthesis Bacteriostatic  Inhibit bacterial protein synthesis Bacteriostatic  Inhibit bacterial cell wall Bactericidal  synthesis   Inhibit bacterial protein synthesis Bactericidal  Inhibit bacterial protein synthesis Bacteriostatic  Disrupt multiple cell-membrane Bactericidal    Understanding that infections are ultimately dealt by the  host’s immune systems, and antibiotics play only an adjunc-  tive role, is critical. Antibiotic therapy should be reserved for  those with clearly established infection. Surgical treatment  of the infection also should be initiated as early as possible.   Antibiotics help in preventing infections after a contami-  nation has happened or they can abort a developing infec-  tion, if administered early. Antibiotics should not be used as  a substitute for the needed surgical treatment.   In most clinical situations, it is easy to determine whether  a patient has an infection—local and systemic findings  would point to the diagnosis. Diagnostic difficulty arises  when a patient who has had a maxillofacial procedure per-  formed, during the second or third day after surgery, devel-  ops swelling and pain. Similarly, elevated temperature and  white blood cell count also may be found. Surgical insult and    Table 10.2 Efficacy of commonly used antibiotics against head and neck pathogens and dosage    Antibiotics Aerobes Staphylococcus Anaerobes Dose  Penicillin Excellent No action Guarded against prevotella, Penicillin G- 6,00,000 —  porphyromonas, fusobacterium, 1,200,000 u q4h im/iv  bacteroides Penicillin V — 250-  500 mg q6h orally  Amoxycillin / Excellent Active Guarded against prevotella, 375-625 mg q8h orally  clavulanate porphyromonas, fusobacterium, 1.2 g q8h im/iv  bacteroides  Cefuroxime Excellent with all except guarded Active No action against prevotella, 1.5 g q8h im/iv  action against capnocytophaga and no porphyromonas, fusobacterium,  action against eikenella bacteroides  Erythromycin Good, guarded against Active Guarded action against fusobacterium, 250-500 mg q6h orally  capnocytophaga & eikenella no action against prevotella, 1-4 g /day in divided  porphyromonas, bacteroides doses q6h iv for severe  infections  Clindamycin Excellent Active Active 150-300 mg q8h orally  1200-2400 mg /day in  divided doses q8h for  severe infections  Ciprofloxacin Good Guarded action Guarded action 500 mg q12h orally  400 mg q12h iv  Metronidazole No action No action Active 400 mg q8h orally  500 mg q8h iv    prolonged general anesthesia often result in these symptoms.  Clinical judgment is important in making the diagnosis, and  the clinician should weigh all information available before  making the diagnosis of infection.   There are a few basic guidelines to be followed in the  administration of antibiotics (Table 10.3).    In severe infection, parenteral antibiotics are needed to get  adequate blood levels. But with an initial response within  couple of days, one is always tempted to switch to oral  administration. When this is done, the infection may recur  because blood levels achieved with oral dose are suboptimal.  Maintenance of peak blood levels of antibiotic, until eradica-  tion of bacteria, is important, which may take 5-6 days. After  the fifth day of parenteral administration, the blood levels  achievable with oral administration are usually sufficient.    A frequently asked question about penicillin allergic  patients is whether the cephalosporins can be used safely.  Overall the frequency of crossallergenicity between the two  groups of drugs is low (7—18%) [10, 11]. Cross-allergenicity  appears to be most common among penicillin, aminopeni-  cillins, and early-generation cephalosporins, which share  similar R-1 side chains; this is thought to increase the risk    of cross-reactivity. Patients with a history of anaphylaxis to  penicillins should not receive first- or second-generation  cephalosporins, while third- and fourth-generation cepha-  losporins should be administered with caution, preferably  in a monitored setting.    The patient should be monitored for the response to treat-  ment and any deterrent should be identified and rectified. A  second empirical choice should be avoided, if at all possible  because the likelihood of success is substantially less. Repeat  cultures may also be attempted.   In some cases, the patient may respond well to the empiri-  cal antibiotics, but the culture and sensitivity report would  reveal that the organisms isolated are resistant to the antibiot-  ics being used. The combined surgical and antibiotic treat-  ment, along with natural host defenses, would have resulted  in resolution of infection. The antibiotic may or may not  have played an important role. The antibiotic that was clini-  cally effective for the patient should be continued despite the  contradictory data.    The original guidelines for timing and use of antibiotics to  prevent infection postoperatively were established by Burke  and Miles et al.’s experimental observations [12, 13]. They    . Empirical therapy  Identification of the organisms—obtain culture & sensitivity in  (a) Compromised host defenses  (b) Persistence of infection in spite of appropriate antibiotics &  surgical therapy.  (c) Postoperative infection  (d) Suspected cases of actinomycosis, osteomyelitis  . Use of specific narrow-spectrum antibiotic—to prevent/  minimize bacterial resistance [6] & superinfections [7].  . Reserve combination therapy for:  (a) Patient with life-threatening sepsis of unknown cause  (b) Increased bactericidal effect against a specific organism is  required  (c) Prevention of rapid emergence of resistant bacteria—e.g.,  tuberculosis  (d) Empiric treatment for certain odontogenic infections—that  are rapidly progressing posteriorly around the neck space  . Use of antibiotics with proven history of success  . Use of the least toxic antibiotic  . Use of a bactericidal rather than a bacteriostatic drug  . Proper administration: Dose, time interval, route of  administration, & consistency in the route of administration  . Cost of the antibiotics    . Patient monitoring—initially a subjective sense of feeling better,  then look for reduction in swelling, pain, & temperature [9]  . Causes of failure of antibiotic therapy:  (a) Inadequate surgical intervention —  (i) Failure to drain pus,  (ii) Increasing pressure inside tissue spaces,  (iii) Retained nonvital tissue or foreign body.  (b) Other sources of infection—IV catheter, Foley’s catheter  (c) Reduced or compromised host defenses—  immunocompromised, malnourished, dehydrated patients  (d) Mistakes in antibiotic administration  (i) Improper route of administration,  (ii) Inadequate dosage,  (iii) Patient noncompliance,  (iv) Incorrect carrying out of physician’s orders.  (e) Wrong culture report or misinterpretation of the culture  report    noted that antibiotics must be given within 4 h after injection  of bacteria into a surgical site to prevent the aggressive level of  infection that occurs when no antibiotics are administered.    Indications for antibiotic prophylaxis [15, 16] are given  in Table 10.4.   Condition & bacterial contamination of the surgical area:  Surgical wounds are generally classified into clean,  clean—contaminated, contaminated, and dirty/infected  [16-18] (Table 10.5).   With judicious use of antibiotics, the infection rates are  known to be lesser [16, 18].   (c) Disease related—poorly controlled diabetes, cancer,  leukemia, alcoholic cirrhosis, end-stage renal diseases   Surgical procedures in which there is a high mortality / morbidity    The selected antibiotic should be bactericidal against the  most common microorganisms that cause infection in the  oral cavity. The bactericidal antibiotics rely less on the  host defense mechanisms providing faster results [18].  The concentration of antibiotics in the tissue should be suf-  ficient to fight the bacteria that may enter the surgical wound  at incision or during the course of surgery. To achieve a  blood concentration of three-four fold that of minimum  inhibitory concentration, the antibiotic is typically given at  twice the treatment dose / h prior to surgery [14, 16].    tive dose. In cases where the surgeon feels that postoperative  infection is a high possibility, the drug can be extended post-  operatively as deemed necessary [19] (Table 10.6).    One must be vigilant in identifying cases where antibiot-  ics are required for the success of surgery, as antibiotic usage  and overusage have considerable risks [6, 7, 20, 21]—gastro-  intestinal disturbances, toxicity reactions, antibiotic resis-  tance and superinfections, anaphylaxis, pseudomembraneous  colitis, etc.    Infection, one of the most common postoperative complica-  tions, can be prevented by the timely use of appropriate anti-  biotic. In spite of many studies in literature, a definitive  conclusion cannot be made regarding the need for antibiotic  prophylaxis in maxillofacial surgery and, if needed, the dose  required. The antibiotic prescription pattern is still hugely  based on personal preferences and shows wide regional vari-  ation, which many a time is inappropriate. The drugs would  be initiated either at an incorrect time, or would be continued  beyond the time required, and this has greatly contributed to  the emergence of resistant bacteria [6].   Prophylactic use of antibiotics should be evidence based  taking into consideration the effectiveness and the possible  adverse outcomes of antibiotic therapy. Moreover, a thor-  ough knowledge of the likely organisms involved in the  infection is needed to prevent the prescription of unsuitable  antibiotics. Antibiotics, if needed, should have a spectrum  of activity that involves streptococci, anaerobic Gram-  positive cocci, and anaerobic Gram-negative rods, which  are considered the most pathogenic for oral infections and  should be bactericidal and the least toxic agents available -  amoxicillin being the most common choice of the clini-  cians [12, 18].   The need for antibiotic prophylaxis and the preferable  drugs for wisdom teeth removal, orthognathic surgery, dental  implants, maxillofacial trauma, and in special circumstances  like patients with diabetes mellitus, patients—pre- and post-  organ transplant, rheumatic heart disease—valve replace-  ments, oncological surgery & reconstruction, cleft surgeries,  etc. are mentioned in the following sessions.    Though one of the most commonly performed minor oral  surgical procedures, the reported infection rate with the  removal of mandibular third molars is <10% [22]. However,  the rate can be as high as 25% when the patient’s immunity  is compromised [20]. The infection rate associated with the  corresponding procedure in maxilla is quite low, <1% [20,  22]. The higher rate of postoperative infection in relation to    mandibular third molar has been attributed to the reduced  vascularization and the gravity-induced pooling of bacterial-  rich saliva.   The prophylactic use of antibiotics in wisdom teeth  removal had been an issue of many debates. There are stud-  ies for [20, 23] and against [24, 25] the practice of antibiotic  prophylaxis in third molar removal. Considering the poten-  tially contaminating oral environment in which the third  molar removal is carried out, it is reasonable to favor antibi-  otic prophylaxis. Moreover, since the postoperative infection  and alveolar osteitis, an inflammatory response whose etiol-  ogy could be traced to bacterial contamination and fibrinoly-  sis of the socket blood clot, cause debilitating pain and severe  functional impairment, it is only prudent to consider the use  of prophylactic antibiotics.   Studies have shown that preoperative administration of  antibiotics reduces the postoperative infection when admin-  istered 1-2 h prior to the procedure [26, 27]. Amoxicillin/  amoxicillin—clavulanic acid is the widely used antibiotic in  the prophylaxis for the surgical removal of impacted teeth  [28] and when given as a single dose preoperatively is found  to reduce postoperative infection and alveolar osteitis [21].  But certain other studies have failed to show a considerable  difference between amoxicillin, clindamycin, metronida-  zole, and placebo in terms of postoperative infection rates  [25]. Studies have found topical tetracycline [29], chlorhexi-  dine irrigation [30],& metronidazole dressings [31]into the  mandibular third molar sockets, effective in reducing the  postoperative infection & the incidence of dry socket.  Review of literature does not give definite indication to use  of antibiotics as prophylaxis in healthy patients or asymp-  tomatic impacted teeth and in case of the removal of maxil-  lary wisdom teeth [22].   Studies have advocated the use of antibiotic prophylaxis  in immunocompromised patients to prevent infection after  surgical removal of impacted teeth [22].   Two recent meta-analyses [28, 32] summarize the antibi-  otic prophylaxis in wisdom teeth removal (Table 10.7).    Dental implants play a crucial role in the successful resto-  ration of missing dentition. The success rate of dental  implants is high, with only 0-10% of reported failure rates  [33]. However, risk of failure is high during the first year  after implant placement [34]. The implant surfaces can  become colonized by oral and perioral microorganisms  during surgery (perioperative contamination) [35]. This can  lead to pain, swelling, bone loss, and eventually failure of  implants. The failure of the dental implants is multifactorial  (Table 10.8).    1 Factors influencing the rate of postoperative infection [20, 32]  may need to consider postoperative antibiotics  History of pericoronitis  Smoking  Old age  Poor oral hygiene  Duration of surgery  Amount of bone removal  Presence of foreign bodies—hemostats or devitalized bone  fragments  Operator skill  2 Amoxicillin & Amoxicillin—clavulanic acid equally effective  [28]  Systemic administration more effective [32]  Single preoperative dose: 30-90 min prior to procedure [18, 32]  Usually double the usual strength is given preoperatively [18, 26]  Antibiotics reduce incidence of alveolar osteitis [21].  Topical tetracycline [29], chlorhexidine [30], & metronidazole  [31] effective in reducing the infection rate  8 Preoperative and extended postoperative doses may be required in  immunocompromised patients [22]  9 No antibiotic prophylaxis required in removal of asymptomatic  mandibular third molars and maxillary third molars in healthy  individuals [22]   . Increased duration of the procedure [20]  . Operator skill [20]    Hence all these local, systemic, surgical, and procedural  factors contributing to implant failure should be eliminated  before considering infection as the reason for failure [33].   Because of the morbidity associated with infection of the  implants, antimicrobial therapy is routinely used with the  aim of prevention of surgical site infection. Though by defi-  nition, dental implant placement is a clean-contaminated sur-  gery with 3—11% chances of infection, the infection rate can  be brought down to about 1% by proper patient selection,  attention to surgical details, and by judicious use of antibiot-  ics [18].   There are studies supporting antibiotic use to reduce  implant failures [33, 34] and studies that fail to show any    added benefits of antibiotics against implant failurte [36].  Few other studies have observed similar failure rates for the  implants with a single preoperative dose and routine use of  antibiotic for 7 days [37].   The currently advocated dose of antibiotic prophylaxis  for implant surgery is 2—3 g of amoxicillin 2 h prior to mul-  tiple implant placement, especially along with bone graft  [33]. If the patient is allergic to penicillin group, 600 mg  clindamycin should be given | h before surgery. For sinus  augmentation, 1.2 g of amoxicillin/clavulanic acid starting  day before the surgery is the prophylaxis of choice [33].  Chlorhexidine gluconate mouth rinses have been known to  reduce the number of pathogenic microorganisms, by lysing  the bacterial cell membranes, and by virtue of its substantiv-  ity, can get retained in the oral soft tissues and get released  slowly for up to 12 h [30, 33]. The key points in the antibiotic  prophylaxis for dental implants are given in Table 10.9.    Orthognathic surgical procedures aim to correct the facial  deformities and malocclusion, thereby improving the func-  tional disorders of the stomatognathic system. It is an elec-  tive procedure, usually carried out in young healthy adults. It  is considered as a clean-contaminated procedure with a  reported infection rate of 3—11% [18, 39]. But certain studies  have reported the rate of infection after orthognathic surgery  to be as high as 6—33.4% [39]. The postoperative infection  was found to be related to poor oral hygiene and the habit of  smoking.   The surgical site infections (SSIs) that develop can be  incisional SSIs and organ and space SSIs [40]. Both types of  SSIs can occur after orthognathic surgery and may develop  within the first few weeks after surgery. The development of  SSIs increased the total length of hospital stay and expendi-  ture. Though the potential for postoperative infections after  orthognathic surgery is known for a very long time, a con-  sensus has not yet been achieved with regard to the drug that  is useful, the dose, and the duration of administration.   The specific orthognathic procedure that has been associ-  ated with higher infection rate was mandibular sagittal split  osteotomy, especially where a transbuccal approach had  been adopted for fixation [38]. Increased rate of infection  associated with mandibular procedures has been attributed to  the diminished vascularity of mandible in comparison with  maxilla and pooling of food and saliva along the vestibular  incision line in the mandible. Till the incision seals off, oral  microflora can freely enter the deeper tissues from the pooled  saliva. Though concomitant extractions, especially of par-  tially erupted mandibular third molars had been implicated  as a risk factor for the development of postoperative infec-   Procedure in a well-monitored asceptic environment—  disinfection, draping, hand scrubbing, sterile gowns & gloves,  sterile instruments   Prevent contamination of implants with contact with skin,  infected oral mucosa, & sinus lining   Bactericidal antibiotic with coverage against pathogenic oral  microflora [12, 18, 33]   Preoperative administration of antibiotics—1 h before the  procedure, twice the therapeutic dose [18, 33]—Amoxicillin 2gm,  / clindamycin 600 mg | h prior to surgery   Chlorhexidine gluconate rinses—hugely effective in controlling  the immediate local infection [30, 33].   2 Single preoperative dose + Chlorhexidine 0.12% rinse twice daily  in healthy individuals [33]   (a) Multiple implants with minimal tissue reflection,  (b) Immediate extraction & implant placement,  (c) Socket bone grafting.   3 Single preoperative dose + 3 doses / day X 3 postoperative  days + Chlorhexidine 0.12% rinse twice daily in healthy  individuals [33]   (a) Multiple implants with extensive tissue reflection,  (b) Multiple extractions & implant placement,   4 Single preoperative dose + 3 doses / day X 5 postoperative  days + Chlorhexidine 0.12% rinse twice daily [33]   (d) Block bone grafting—autografts,  (e) Indirect sinus floor lift procedures,  (f) Active periodontal disease.   5 Loading dose on the previous day + 3 doses / day X 5  postoperative days + Chlorhexidine 0.12% rinse twice daily [33]  In sinus lift procedure    tion, studies were not able to support or refute this [38, 41]  Longer surgeries involving multiple/segmental procedures  also show a higher rate of infections [12, 18, 38].   Use of various antibiotics has been proposed—penicillin  [42], ampicillin [43], amoxicillin with or without clavula-  nate [43], clindamycin [42], or a member of the cephalospo-  rin group [19, 41]. Literature fails to report a significant  difference in the infection rate when using a penicillin or  nonpenicillin group of antibiotics or among the various  types of penicillins [18, 19, 44]. Based on the bacteriologi-  cal studies, penicillin, amoxicillin, or amoxicillin—clavu-  lanic acid or cephalosporins is commonly recommended in  the preoperative antibiotic prophylaxis for orthognathic sur-  gery [19, 38, 41-44].    The preoperative single dose of antibiotic increases the  level of the drug in circulation prior to incision. Whether  short-term antibiotics (single dose or dose x 24 h) [ 42] or  extended-term antibiotics (for more than 24 h) [ 41, 43] is  beneficial in the prevention of postoperative infection after  orthognathic surgery is still a debatable question [19, 38,  41, 44].    10.3.5 Is Antibiotics Needed when Bone  Plates and Screws Are Being Inserted?    One question that keeps on surfacing is whether prophylactic  antibiotics are needed in cases where bone plates and screws  are used to hold the bony segments together. Any foreign  body inserted into the body, be it a medical device or implant,  may elicit a foreign body reaction. Moreover, the microor-  ganisms can colonize on the implant surface in a biofilm,  while they are being inserted, and as the physical presence of  the implants may compromise the blood supply to the region,  thereby reducing the delivery of body’s immune cells to the  region and resulting in infections at the host —implant inter-  face by normal flora with low virulence [45, 46]. The oral  biofilm and its toxins, adhered to the surface of titanium  plates and screws used for stabilization of osteotomy seg-  ments, could be a source of local or regional infectious com-  plications [19]. Hence, the use of antibiotic prophylaxis is  justified.   Take-home points regarding antibiotic prophylaxis in  orthognathic surgery are mentioned in Table 10.10.    In today’s world of fast-moving vehicles and expressways,  hundreds of thousands of people get involved in road traffic  accidents. Head and face are among commonly injured body  parts. Both the soft and hard tissues of the face may be  involved in the trauma. Firearms, contact sports, and inter-  personal violence are other reasons for facial injuries. The  management of these injuries should follow protocols and be  done in a systematic manner. With advances in anesthetic  and surgical techniques and availability of better implant  materials with favorable metallurgy, open reduction and  internal fixation (ORIF) has become the norm. The re-  establishment of form, function, & cosmesis is of paramount  importance. To arrive at this goal, the probable complica-  tions of ORIF need to be prevented or managed correctly. Of  the various complications reported, none has generated more  interest and controversy than the occurrence of postoperative  infection. By adhering to the standard surgical protocols and  strict aseptic techniques, the occurrence of postoperative    1. Risk factors for SSIs [47, 48]  (a) Longer surgery;  (b) Short-term antibiotic prophylaxis;  (c) Extraction of a third molar during surgery;  (d) Greater number of osteotomies performed;  (e) Older age;  (f) Smoking;  (g) Poor oral hygiene;  (h) Compromised immune system.   3 Need for antibiotics in presence of bone plates & screws [45, 46].   Loading dose of double strength 1 h prior to incision [18].   5 Confusion between—single loading dose + short-term doses x  24 h vs long-term antibiotics for more than 24 h [19, 44].  Commonly isolated organisms—aerobic bacteria—streptococci  (43%) & anaerobic bacteroides (50%) [18, 39]   9 Concomitant removal of mandibular third molars does not  increase the risk for postoperative infection [39], though may  cause issues with fixation.    infection can be brought down considerably. But the pres-  ence of the microorganisms in the oral cavity and facial skin  and possible contamination from environment necessitate  the consideration of antibiotics in the maxillofacial trauma  management.   Though prophylactic antibiotics were considered essen-  tial in the management of maxillofacial trauma for many  years [18], the evidence for this preventive intervention was  weak and confusing. Among facial fractures, mandibular  fractures are most commonly studied, because of the com-  pound nature of the fractures, except in the ramus—condyle  unit, where the fractures usually do not communicate with  the external environment. Fractures of the mandibular con-  dyles or Lefort fractures of maxilla are rarely infected when  compared with the fractures involving mandibular angle,  body, or symphysis [49, 50].   The decision to use antibiotic prophylaxis depends on  whether the fracture is an open or closed type and whether  it is going to be managed with open or closed reduction.  Open procedures were four times more commonly prone to  postoperative infections according to a few studies [41, 51,  53, 54], whereas certain other studies reported no differ-  ence between the patients treated with closed reduction and  maxillomandibular fixation and those who underwent open  reduction and internal fixation [54]. The microbiology of  the infected fractures was mixed and responded to beta-  lactam antibiotics well.    1. Risk factors for SSIs [22, 32, 51, 56]  (a) Longer surgery;  (b) Older age;  (c) Smoking;  (d) Poor oral hygiene;  (e) Compromised immune system.  2 Mandibular fractures/ fractures of the teeth-bearing area—open /  compound fractures.—Antibiotics needed [49, 50, 53, 54].  Need for antibiotics in presence of bone plates & screws [45, 46]  Loading dose of double strength 1 h prior to incision [18, 56].  Beta-lactam antibiotics—preferred [56].  Higher infection rate—in fractures involving mandibular  teeth—bearing areas [49]  7 Longer duration of antibiotics in immunocompromised patients  [49, 52].  8 Chances of infection more with open reduction than in those  treated with closed reduction with no antibiotic prophylaxis [16,  50, 51]. But with single dose of perioperative antibiotics, no  significant difference between closed & open reduction [51, 54]  10 Delayed healing and increased infection rate with tobacco  smoking [51].    Studies have shown that single dose of preoperative anti-  biotic prophylaxis is sufficient to prevent wound infection  [51, 54]. If the surgery extends beyond the half-life of the  antibiotic, the antibiotic can be redosed [51]. The need for  postoperative antibiotics in the maxillofacial trauma too has  been extensively studied [16, 49, 53, 55, 56]. These studies  reported no statistically significant difference in the develop-  ment of SSIs between the patients who had received periop-  erative antibiotics and those who had received extended  antibiotics in the postoperative period.   Longer antibiotic usage has been advocated in the immu-  nocompromised patients [32, 52, 56]. The habit of tobacco  smoking was found to have a deleterious effect on the heal-  ing of mandibular fractures by inducing hypovascularity and  prolonged inflammation [54]. The other major factors, which  contribute to the occurrence of SSIs, are poor oral hygiene,  extremes of age and malnutrition [22, 32].   Important points mentioning the need for antibiotics in  the management of maxillofacial trauma are given in  Table 10.11.    Diabetes mellitus is a metabolic disorder resulting in ele-  vated glucose levels, due to inadequate insulin secretion  (type I) or reduced insulin secretion with an accompanying  insulin resistance (type II). Diabetic patients pose a special  challenge to the surgeon as the balance between the insulin  they can secrete and the hyperglycemia induced by surgical  stress-adaptive hormones catecholamines, cortisol, growth    hormone, and glucagon is lost. Patients, who are nondia-  betic, usually are able to handle this glucose overload effec-  tively, whereas diabetic patients may have issues resulting in  cardiovascular complications, infection, and reduced rates of  wound healing. Moreover, the defective polymorphonuclear  leukocytes function and macro- and microvascular dysfunc-  tion resulting in compromised local circulation increases the  susceptibility to infections [57]. With the vast microbiologi-  cal colonization of the oral cavity, it has always been assumed  that maxillofacial surgical procedures carry a high risk of  infection and prolonged or delayed wound healing. The  guidelines as to the prophylactic use of antibiotics in diabetic  patients had been vague as “....are more prone to infection  necessitating routine antibiotic prophylaxis for all maxillofa-  cial procedures” [58].   In many of the literature surveys, authors have noted that  well-controlled diabetic patients are at no increased risk of  postoperative infection than normal healthy patients and  delayed wound healing is not a pressing concern due to the  rich vascularity of the region [59, 60]. Antibiotic prophylaxis  is warranted only in conditions where a normal patient also  would benefit from it. Poorly controlled diabetic patients  would require normalization of their hyperglycemic state  prior to elective procedures. In emergency situations, antibi-  otic prophylaxis prior to the surgical incision is desirable and  attempts should be made to control the glycemic level during  the peri- and postoperative period [58-60].    Head and neck oncology patients usually require a major  surgical procedure +/— with radiation therapy. The surgical  site tends to be large, the surgical time and postoperative  immobilization period longer. The surgical management  attempts at removal of the tumor, clearance of the neck  nodes, and involves an additional surgical site from where  flap is harvested for reconstruction—either microvascular  flaps or pedicled ones [61]. The large wound area exposed to  local flora of the oral cavity and the skin is at risk of wound  contamination and infection. Nosocomial infections are  known to run a protracted course and pre-existing general  comorbidities further increase the morbidity and, thus, the  hospital expenses associated with these surgeries.   The reasons for increased infection rate are mainly the  number of procedures carried out in the same operation  (excision, neck dissection, tracheostomy, and distant flap  harvest), the pooling of saliva due to difficulty in swallow-  ing, leading to aspiration, and the inability in obtaining a  watertight closure when the flap is inset in the recipient bed  leading to salivary leak and contamination of neck wounds  with saliva [62, 63].   Probable pathogens [62] - Escherichia spp. & staphylococcal spp  Preferred antibiotic [62] - ampicillin & sulbactum   Bartella et al. (2017) [62] - Statistically significant reduction in  infectious complications with postoperative antibiotics    The need for antibiotic prophylaxis is well established in the  oncologic surgery, but the need for a long postoperative course  of antibiotics is still debated upon. There are studies, which  have shown benefits of prolonged antibiotics in preventing  postoperative infections like pneumonia, urinary tract infec-  tions, sepsis, and SSIs in patients who had oral squamous cell  carcinoma [64], and there are studies, which have shown no  extra benefits of prolonged postoperative antibiotics [63, 64].   Escherichia spp. and Staphylococcus spp. are predomi-  nantly responsible for the infections and in 72% were sensi-  tive to ampicillin & sulbactum [62].   A few key points, which would be beneficial in making a  decision, are given in Table 10.12.    Orofacial clefting is one of the more common congenital  anomalies and cleft lip & palate deformity is the most com-  mon among them. Management of cleft lip & palate defor-  mity involves staged procedures and spans over 12-16 years.  The management aims at correction of the deformity so that  function and cosmesis are restored as much as possible and  the psyche of the individual is minimally scarred.  Postoperative infections can result in wound breakdown,  poor speech & esthetics, and nasal regurgitation of food in  cleft lip and palate patients.   Various authors had reported on obtaining swabs from  nose and oral cavity to identify the possible pathogens and  using antibiotics according to the culture reports before cleft  lip and palate repair [65-67]. The pathogenic bacteria iso-  lated from the swabs were Staphylococcus aureus and beta  hemolytic streptococci [67]. But later studies demonstrated  that there were not many differences between the group that  underwent swab acquisition and corresponding antibiotics  therapy and the group that didn’t receive any antibiotics in  terms of postoperative complications [68]. The rate of com-  plications was found to be independent of the potential  pathogens in the mouth [65].   Factors, which have been implied as contributing factors  to wound dehiscence, are given in [66, 67] Table 10.13.    In a recent prospective study, Azner et al. (2015) noted a  statistically significant reduction in the incidence of palatal  fistulas with 5 days of postoperative antibiotics [69]. But  80% of their control group, who had received no postopera-  tive antibiotics, too healed without any complications. Both  study and control groups had received a single dose of cefu-  roxime 30 mg / kg body weight, before incision. The use of  one dose of antibiotics before incision has been advocated by  other authors also and may be more effective in preventing  complications related to wound infection than a prolonged  course of postoperative antibiotics [68].    The concept of organ donation had always excited mankind.  Twentieth century saw developments that made the dream of  replacing a diseased organ with a healthy one a reality.  Understanding the human immunology and the development  of powerful immunosuppressant drugs laid the foundation  for modern transplant medicine, making transplantation of  kidney, liver, lungs, and heart a successful treatment option.  As the transplant science advanced, so did the numbers and  life span of transplant patients and their need for dental/max-  illofacial surgical procedures. As these patients are on immu-  nosuppressants, they are more prone to opportunistic  infections and their sequel. Hence, care must be given to  treat or remove the existing/potential sources of infection  before the transplant procedures.   In a pretransplant patient, the need for maintaining oral  hygiene should be stressed upon. The treating physician  should be consulted with regard to the fitness to undergo the  planned procedures and the safety of using any drugs if  required. Drugs, which have a hepatic metabolism or renal  clearance, should be used with caution in patients with com-  promised liver or kidney function. The selection of antibiot-  ics is made after careful evaluation of the existing pathology  and the chances of spread of infection with the planned den-  tal treatment.   In the immediate post-transplant period—the first 3  months post-surgery, the graft, and the patient are very vul-  nerable to any insult—graft anastomoses are susceptible to  endarteriris due to bacterial colonization as they are not yet   2. Aggressive management of infections.  3 months postop—noninvasive elective procedures  6 months postop—invasive elective procedures under antibiotics  Beta-lactam antibiotics - relatively safer to be used in renal and  hepatic transplant patients [72]  No consensus on minimally invasive procedures in patients with  meticulous oral hygiene [71]    fully epithelialized. Hence, only emergency procedures  should be done. Any acute orofacial infection developing  should be managed aggressively, surgical drainage, culture  and sensitivity of the organism, and appropriate antibiotics  would be required [70]. After 3 months, elective, noninvasive  procedures can be carried out. Since the patients who have  undergone organ transplantation are immunosuppressed and  are at high risk of infection, prophylactic antibiotics need to  considered for any invasive dental procedures, even after  6 months. Beta-lactam antibiotics are relatively safer to be  used in renal and hepatic transplant patients [71]. But for  those with meticulous oral hygiene, there is no consensus  regarding the need for antibiotic prophylaxis for minimally  invasive procedures [71]. The decision to use antibiotics  should be done on a case-to-case basis.   Important points to be kept in mind while contemplating  antibiotic prophylaxis in organ transplant patients are given  in Table 10.14.   Bacterial endocarditis, a rare but life-threatening condition,  was initially described by Lewis & Grant in 1923 [72].  They suggested that bacteria released into the blood stream  after a dental procedure colonize on the heart valves or the  endocardium. The bacteremia associated with infections of  skin and soft tissues, genitourinary tract, and gastrointesti-  nal tract are also known to result in infective endocarditis  (IE). Bacteria can gain direct access to the bloodstream  through the indwelling catheters. The American Heart  Association (AHA) came up with the first guidelines to  reduce the risk of IE following invasive procedures in 1955  [73]. The AHA guidelines have been updated regularly  since then and the latest one was released in 2007 [74]. The  2007 guidelines categorized cardiac conditions into having  a low risk, moderate risk, and high risk of developing IE  and advocated the use of antibiotic prophylaxis only in   Congenital heart diseases—unrepaired, with palliative shunts or  conduits or repaired with prosthetic material or those repaired, but  with residual defects    high-risk-category patients (Table 10.15) who were to  undergo dental procedures that involved the manipulation  of gingival tissues or the periapical region of teeth or inci-  sion of the oral mucosa.   The guidelines prescribed a single dose of antibiotic  30-60 minutes prior to the procedure—Amoxicillin 2 g PO,  Cephazolin/Cephtriaxone 1gm IV/IM, or Clindamycin  600 mg PO/IM/IV, depending on whether the patient is  unable to take oral preparations or is allergic to penicillin or  not [74]. The reason for the revision of the antibiotic policy  was predominantly the observation that IE is more likely to  result from transient bacteremias caused by routine daily  activities, like chewing food, and by regular oral hygiene  care. The authors concluded that maintaining optimal oral  hygiene is more important in reducing the risk of IE and the  adverse effects of antibiotics exceeded the benefits of antibi-  otic prophylaxis. The British Society for Antimicrobial  Chemotherapy (BSAC) also recommend antibiotic prophy-  laxis only in those who have a history of healed IE, pros-  thetic heart valves, and surgically constructed conduits [75].  The advice to the patient is to concentrate on achieving and  maintaining meticulous oral hygiene as this has been found  to reduce the risk of IE. Similar observations were made by  the National Institute for Health and Care Excellence (NICE)  [76] and the European Society of Cardiology (ESC) [77].   There has been a rising concern over the potential for an  increased incidence of IE and a worse prognosis for the dis-  eased since the guideline changes by the AHA, NICE, ESC,  BSAC. Several studies have been carried out to assess the  impact of these changes on the disease incidence in adults  and pediatric population. Whereas earlier studies showed not  much difference pre- and post-guideline changes in inci-  dence [78], recent studies have noted a definite increase in  the incidence of IE post-guideline changes [79]. Sakai et al.  in 2017, though noting no change in the incidence and sever-  ity of IE in pediatric patients, pre- and post- guideline  changes, reported an increase in the viridans group strepto-  cocci (VGS)-induced IE in older age group [79]. The data  from these studies point to the need for further investigation  into the effectiveness of 2007 guidelines, though it has been  argued that the increase in IE incidence may be related to the  increasing life span of the patients with congenital heart dis-  eases and prosthetic devices and increase in the number of  invasive procedures being performed on them.    The International Association for the Study of Pain (IASP)  defines pain [80] as: “an unpleasant sensory and emotional  experience associated with actual or potential tissue damage  or described in terms of such damage.”   Pain is the most debilitating postoperative symptom and  its control or elimination is usually the primary goal in post-  operative management of a patient. Inadequate pain control  resulting in patient distress is the most common cause of an  increased length of hospital stay. The postoperative pain,  inflammatory in character, is a temporary one persisting only  until healing. But severe, acute, repetitive, postoperative pain  increases the risk of the pain becoming chronic and may lead  to allodynia and hyperalgesia [81]. Orthognathic surgery  patients may continue to feel the pain even after 1 year of  surgery [82] Hence, appropriate pain management is critical  to achieving a successful surgical outcome. Prevention of  pain is more efficient than the treatment of pain. For this, an  understanding of basic pathophysiology behind pain mecha-  nism is important.    Pain is initiated by the excitation of nociceptors, receptors  that respond to noxious - mechanical, thermal, and chemical  stimuli. Sensory nociception is disproportionately greater in  the head and oral cavity when compared with other parts of  the body. Often a patient’s overanxiety about undergoing an  elective surgery would result in an increased intensity of the  perceived pain [83].   Surgical insult results in tissue trauma and initiates a  chain of inflammatory events, causing a release of chemical  substances responsible for nociceptor excitation. Trauma  releases tissue phospholipids, which are converted into ara-  chidonic acid due to the action of phospholipase A2 and the  consequent conversion of this substance into prostaglandins,  prostacyclins, and leukotrienes due to the action of cycloox-  ygenase (Cox) and lipoxygenase enzymes. These locally  released chemical mediators sensitize the nociceptors and  cause vasodilatation, with a consequent increase in cell per-  meability and edema. Trismus after a maxillofacial surgery  is a sequela to the postoperative edema around the masticator  muscles and is aggravated by pain [84]. The physiological  responses to tissue trauma, pain & edema, can be managed  successfully by inhibiting the pathways that produce the  chemical mediators, before the occurrence of surgical trauma  (Fig. 10.1).   Similarly, mechanisms, which enhance the endogenous  pain inhibition and anxiolysis and patient education, can    modify cortical processing of pain perception [85]. All these  measures collectively lead to an efficient postoperative pain  management.    Postoperative pain has a protective function as it allows for  undisturbed healing of the operated tissue by restricting  movements. The aim of postoperative pain management is  to reduce pain significantly, but not to eliminate it com-  pletely [86]. Overall postoperative pain experience could  be reduced by paying attention to lessening of the pain dur-  ing the surgical procedure itself. Pre-emptive analgesia is  defined as an antinociceptive treatment that is started pre-  operatively and is active during surgery, reducing the phys-  iological consequences of nociceptive transmission [87].  Since the introduction of the concept of pre-emptive anal-  gesia by Woolf in 1983, many attempts to reduce the pain  by using analgesics and adjunctive measures, such as the  administration of long-acting local anesthesia, corticoste-  roids, and intraoperative nitrous oxide analgesia, have been  reported [88]. These should be given before the surgical  incision and should be timed so that the maximum plasma    concentration of the drug is reached at the time of surgical  incision. This will prevent the release of the inflammatory  mediators, giving immediate analgesic effects. The use of  IV analgesia has an added benefit over oral administration,  as following oral administration analgesics reach maxi-  mum concentration after 1.5 h, whereas intravenous admin-  istration results in maximum concentration in a short  period.   Numerous studies have shown beneficial effects of the  preoperative administration of ibuprofen with paracetamol  [89] piroxicam [90], ketorolac [91], meloxicam [92],  parecoxib [93], and dexamethasone with rofecoxib [94].  There had been contradictory reports also in which the  authors fail to find a clear-cut benefit for pre-emptive  NSAIDS [95, 97]. The authors state that the pre-emptive  intake of analgesics should not be used in all patients as a  general rule. They base their recommendations on the lack of  enhanced analgesic effects and on the potential adverse  effects such as increased intraoperative bleeding [95].   Despite the confusion regarding the effectiveness of the  pre-emptive analgesia, it has been strongly advised to start  systemic analgesics before the local anesthesia effect wears  off and/or give a nerve block with long-acting agent like  bupivacaine [86].    Anxiety & apprehension, fear of the  procedure  Pre-existing or chronic pain    Postoperative analgesia has traditionally been achieved by  prescribing analgesics with instructions to take as and when  necessary. Experience with this approach was that many  patients would not take the medication until the onset of sig-  nificant pain. This practice earned the maxillofacial surgery  the reputation of being an extremely painful one. The truth is  that the postoperative pain management can be successfully  achieved by carefully planning the delivery of the pain con-  trol measures at the appropriate time in the peri- and postop-  erative periods.   Pain perception is a subjective feeling, which is amplified  by many factors and identification of the patients who are “at  risk” for the development of severe postoperative pain would  help in charting out an individualized management plan [97]  (Table 10.16).   Identifying predictors of postoperative pain in patients  before surgery, educating patients at the preoperative visit  regarding the expected pain, and presenting the postopera-  tive pain management plan will prepare patients better and  relieve some of their anxiety regarding the procedure. An  increased awareness of the importance of the psychological  factors will allow more effective pain management.    The postoperative pain management is usually done with  opioids and nonsteroidal class of anti-inflammatory drugs.   Opioids have been in use for moderate-to-severe pain relief  for a long period. References to opium poppy can be found  in Sumerian and Egyptian culture, as back as 300 BC. The  opium poppy, Papaver somniferum, gives rise to more than   Opiate alkaloids exert their action by acting on the opioid  receptors- pt, k, 5 (mu, kappa, and delta), which otherwise  provide sites for activation of endogenously released opioid  substances - beta-endorphins, enkephalins, and dynorphin  compounds, which produce endogenous central analgesia.  Opiate agonists produce analgesia by inhibiting excitatory  neurotransmission of substance P, acetylcholine, noradrena-  line, and dopamine.   Unfortunately, opioid use, even when prescribed for short  periods, comes with certain risks (Table 10.18).   For these reasons, most opioid agents used in outpatient  postsurgical pain management are formulated in combina-  tion with non-narcotic analgesics [104]. This formulation  potentiates the analgesic effects of the individual agents  within the formulation while minimizing the side effects of  pure opioid administration [105].   Tramadol, a synthetic substance with both opioid and non-  opioid properties, is structurally related to codeine. It  exhibits antidepressant and anxiolytic-like effects, in addi-  tion to analgesic action. It is considered safe for long-term  use unlike NSAIDs with their potential for impairment of  renal function and gastrointestinal complications, and with  respect to other opioid medications for its low addiction  rate and favorable safety profile. The most common  adverse effect of tramadol is nausea and vomiting, espe-  cially with oral administration. Tramadol is contraindi-  cated in patients with poorly controlled epilepsy because  of its excitatory serotonergic effects. It is available either    as a single drug or in combination with acetaminophen.  Submucosal injection of tramadol at the extracted site of  third molars has been proven effective in reducing the  postoperative pain [106]. It suffers no side effects of sys-  temic administration.   NSAIDs have been in use for the treatment of pain, fever,  and inflammation since late 1800 [107]. The  anti-  inflammatory and analgesic properties of these drugs with-  out the side effects and the addictive potential of opioids  have made this class of drugs the first choice in ambulatory  dentoalveolar procedures (Table 10.19).   They are a group of chemically heterogeneous com-  pounds with several similar pharmacologic actions like anti-  inflammatory, antipyretic, analgesic, and antiplatelet actions.  They primarily act at the site of tissue injury by inhibiting the  synthesis of prostaglandins within the endoperoxide path-  way (Fig. 10.1).    Historically, majority of the NSAIDs were nonselective  COX inhibitors with side effects related to the blockade of  cytoprotective prostanoids - gastric irritation, increased  bleeding time, and renal impairment. Over the past few  years, selective COX2 inhibitors have been developed, which  block the COX-2-—mediated prostaglandins while maintain-  ing the physiologically beneficial effects of the COX-1 iso-  enzyme [108].   Overall, NSAIDs are safe drugs to be used in the manage-  ment of acute/postoperative pain. Parenteral use of NSAIDs  has shown to be more effective in pain control [109]. About  60% of the patients would respond to the first NSAID, and  the rest would show benefit with another NSAID. Ibuprofen  is a widely used NSAID, with proven efficacy [110]. About  5% people experience “aspirin-sensitive asthma,” probably  due to the inhibition of Cox enzyme. Because of the probable  mechanism of inducing asthma, it is felt that selective Cox 2  inhibitors may not cause asthmatic attacks [111].   Paracetamol or acetaminophen is a widely available analge-  sic with an antipyretic action. It acts by inhibition of the  COX-3 isoenzyme, reducing the production of prostanoids  in the central nervous system. This central inhibition explains  the antipyretic action of paracetamol. Paracetamol shows an  excellent result in relieving mild-to-moderate pain relief and  fever [112]. When used in combination with other analge-  sics, it shows superior analgesic power, thereby reducing the  dose of opioids required [96].    Since there is no definitive evidence or clear algorithms,  the selection of NSAIDs, to a large extent, depends on  clinical experience and side effects. Patient convenience  and cost also play a minor role in the selection of  analgesics.   Laskarides (2016), in his review on control of dental pain,  puts forward his observations (Table 10.20) [113].   WHO initially described the concept of “pain ladder” in their  guidelines for the use of drugs for the management of cancer  pain [114]. The concept has been now accepted in the man-  agement of all types of pain [104]. The concept is based on  the use of first line of drugs for the mild-to-moderate pain  and then climb the ladder to more potent drugs if pain still  persists. Please see chapter on postoperative care, to view the  analgesic ladder.   9 Maximum daily dose of paracetamol 4 g decides the dose of  combination therapy [113].   Pain is multifactorial in origin and multiple techniques and  drugs may be required to achieve control over it. The simul-  taneous use of different classes of analgesics and techniques  has been called preventive, protective, or multimodal analge-  sia [115]. This approach uses a combination of drugs that act  at different sites of action on the nervous system by different  mechanisms to prevent peripheral and central sensitization  of pain. It results in additive analgesia, but with lowered side  effects than the single agents when used alone. Intraoperative  local anesthesia followed by a range of analgesic drugs have  been found to be effective in controlling the pain in day cases  and reduces the need for opioid analgesics [116].   The complex surgeries involving multiple surgical sites as  in head and neck oncological cases and craniofacial surger-  ies would gain hugely from the administration of multimodal  analgesia. Multimodal analgesia can be successfully  achieved by combining the currently available analgesic  modalities (Table 10.21).   Patient-controlled analgesics are intravenous agents, deliv-  ered through a microprocessor-controlled infusion pump, in  which a predetermined dose can be delivered by the press of  a button, and a lockout time can be set, so that patient cannot  overdose himself [119]. PCA is usually used in patients who  are distressed at the thought of postoperative pain. Fentanyl,  morphine, & combinations are the usually used medications.  Though PCA was initially thought to reduce the patient pain  perception, thereby reducing the length of stay (LOS), stud-  ies have failed to show any statistically significant difference    Table 10.21 The analgesics and adjuncts that can be used in multi-  modal analgesia [117]    drugs (NSAIDs) Mefenamic acid,  [108, 110]. nasal spray of  ketorolac  E. Cyclooxygenase Celecoxib Cox 2 inhibitor  (COX)-2-specific  inhibitors [108].  F. Adjuncts.  1. Steroids [80]. | Dexamethasone, Blocks lipoxygenase &  hydrocortisone cox pathways   locus ceruleus and in  the dorsal horn of the  spinal cord,  respectively    presynaptic or  postsynaptic inhibition  of calcium influx,  which inhibits the  release of  neurotransmitters    in the pain score and the LOS between the PCA group &  non-PCA group of patients after orthognathic surgery [119,  120]. This could be attributed to the fact that the subjects in  the PCA group were predominantly bijaw surgery patients  for whom the surgical time was longer and the surgical pro-  cedure resulted in more tissue injury. But from patient’s per-  spective, PCA is the preferred method, as they feel in charge  of their own pain control [121].    When tissue damage occurs as a result of injury, body’s natu-  ral defense mechanism is inflammation and body tries to heal.  But overt inflammation results in pain, edema, and limitation  of movement, trismus. These symptoms may not be evident  immediately, but peak after the second day, returning to nor-  mal by seventh postoperative day [122]. Corticosteroids sup-  press the inflammation (Fig. 10.1) by interfering with the  capillary dialatation, fluid transduation, fibrin deposition, leu-  kocyte migration, and phagocytosis. Under normal nonstress-  ful conditions, the body produces approximately 15 to 30 mg  of hydrocortisone/cortisol per day. During stressful situa-  tions, 300 mg of hydrocortisone per day can be produced.  Generally speaking, to suppress inflammation, the dose of  exogenous corticosteroids must exceed the normal physio-  logical amounts of hydrocortisone released [123].   The first reported clinical use of the anti-inflammatory  properties of corticosteroids was in the treatment of rheuma-  toid artritis [124], following which its efficacy was tried in  maxillofacial surgical procedures. The use of steroids and  their effectiveness have been extensively studied in the third  molar surgeries—the most commonly performed maxillofa-  cial surgical procedure [125]. Markiewicz et al. noted that  postoperative findings of swelling, trismus, and pain were  significantly lower in the group who received corticoste-  roids, than in the control group in the immediate postopera-  tive period (1-3 days) [126].   The use of dexamethasone and methyl] prednisolone, in  controlling the postoperative sequel of third molar surgery  when these drugs are administered via parenteral [127], oral    [128] submucosal [129, 130] and topical [131] routes, has  been reported.   Studies have evaluated different formulations, dosages,  and routes and sites of administration of corticosteroids,  without any consensus. (Table 10.22).   Dexamethasone has a longer duration of action than  methylprednisolone and is considered more potent.  Intralesional/intramasseteric injection of dexamethasone is  found to be better than the intravenous or parenteral admin-  istration in controlling postoperative edema & trismus and  has an additional benefit of being given through an already-  anesthetized area [130, 132].   Almeida et al. (2019) [133] failed to note any benefit of  submucosal injection of steroid at the local site. Authors gave  the reason for this as the displacement of the medicine from  the local site when mucoperiosteal flap is reflected to expose  the tooth. Similarly, the merits of intravenous administration  of steroids perioperatively in major surgeries have been ques-  tioned by a group of authors [134]. Kainulainen et al. [134]  reported infectious complications—pneumonia, gastrostomy  site infections, & surgical site infections in oncological cases.   Though the reduction of edema brings about some reduc-  tion in discomfort, steroids alone do not have a clinically sig-  nificant analgesic effect [130, 135] This has been attributed  to the inability of the steroids to block the production of neu-  rotransmitters by the injured tissues and central sensitization  to pain. The combination of dexamethasone with tramadol or  diclofenac sodium has been proven more effective in con-  trolling postoperative pain and trismus, as opposed to corti-  costeroids alone [136]. Alexander & Throndson [127]  summarized few salient points with regard to usage of ste-  roids, based on their review (Table 10.23).    Table 10.22 Commonly used steroids with their anti-inflammatory potency& equivalent dose and commonly used doses [1]    Drug Duration of action Anti-inflammatory potency Equivalent dose Dose  Dexamethasone Long acting 25 0.75 mg 0.5-5 mg /day PO, 4—20 mg /day IV  Betamethasone Long acting 25 0.75 mg 0.5—-5 mg /day PO, 4—20 mg /day IV  Prednisolone Intermediate acting 4 5 mg 5-60 mg /day PO   10-40 mg / day IM or IV  Methyl prednisolone Intermediate acting 5 4 mg 4-32 mg /day PO  Triamcinolone Intermediate acting 5 4 mg 4-32 mg /day PO   5-40 mg intra-articular  Hydrocortisone Short acting 1 20 mg 100 mg IV/IM bolus    Preoperative intralesional / parenteral administration of steroids to  reduce the inflammation associated with surgery [125, 132].  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Corticosteroid administration in  oral and orthognathic surgery: a systematic review of the literature  and meta-analysis. J Oral Maxillofac Surg. 2010;68:2207-20.    Open Access This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.  org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropri-  ate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.   The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in  a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.   Management of soft tissue wounds needs a careful assess-  ment of the wound, a good understanding of wound types  and healing as well as adequate knowledge and skill for  wound care. The various steps in wound care include cleans-  ing and debridement, hemostasis, tetanus immunization and  antibiotic medication and wound closure.   Wound closure can be accomplished in diverse ways, but  suturing remains the mainstay. A wide variety of materials  are available for wound suturing. One has to choose the right  material and technique depending on the wound type and  closure needs. Alternate techniques such as staples, tapes  and adhesives are fast gaining popularity.    Artificial closure of the wounds is required if significant con-  nective tissue is exposed. Wound closure leads to faster  wound healing with reduced complications. Even though  suturing is the mainstay of wound closure, other alternatives  are fast gaining popularity.    Electronic Supplementary Material The online version of this chap-  ter (https://doi.org/10.1007/978-98 1-15-1346-6_11) contains supple-  mentary material, which is available to authorized users.    R. Veeraraghavan   Department of Oral and Maxillofacial Surgery, Amrita School of  Dentistry, Ernakulam, India    © The Association of Oral and Maxillofacial Surgeons of India 2021    Before going into the intricacies of material selection and  techniques of wound closure, one needs to be clear about the  actual need for artificially closing a wound. The main indica-  tion for wound closure is significant exposure of connective  tissue. In general, there are five reasons behind the concept  of wound closure.    1. Healing by Primary Intention  This is the most important purpose of wound closure. The  open wounds, which are likely to heal by secondary inten-  tion, are made to heal in a ‘more’ primary manner by the  intervention of wound closure. This hastens the healing  process and also reduces scar formation, with resultant  advantages in aesthetic and functional facets.   2. Coverage of Deep Tissues  When the epithelium is breached and connective tissue is  bared, it exposes the inner tissues to mechanical and bio-  logical threats. This threat becomes even more serious  when deeper structures such as the viscera or bone is  exposed.   3. Prevent Contamination  An open wound is under constant attack by the patho-  genic microorganisms, more so in the oral cavity. Such  relentless contamination is likely to lead to a full-blown  infection and/or delayed healing. Sooner the wound is  closed, the lesser the risk of major contamination.   4. Haemostasis  This is not one of the primary purposes of wound closure.  But sutures may help in impeding blood loss by prevent-  ing mechanical disturbance to the clot.   5. Prevention of Dead Space  If only the superficial cutaneous sutures are placed over a  deep wound, a dead space can result beneath the surface.  This condition usually leads to wound breakdown and/or  wound infection. Dead space is prevented by closing the  deep tissues in multiple layers.    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1-15-1346-6_11    Suturing is the process of wound closure by holding the  edges of the wound together using a thread. This thread,  called a ‘suture’, is used to approximate the wound edges  together and to hold them in position till the tissue healing is  sufficiently advanced to maintain themselves in the corrected  anatomic position and alignment to each other. The surgeon  uses a ‘suture needle’ to pass the thread through the tissues  on either side of the wound so as to hold the separated edges  in the proper position.    Apart from the suture thread and needle, some instruments  are used to perform the suturing process. Commonly used  instruments include a needle holder, a tissue holding forceps  and a pair of scissors.   The needle holder (needle driver) is the primary instrument  used for suturing. Similar to a haemostat, it is used to grasp  and manipulate the suture needle to which the thread is  attached. A needle holder has three parts—a pair of beaks, a  joint (‘pivot’) and a pair of handles with rings. Many designs  are available, examples being Webster, Halsey and Mayo-  Hegar. Most designs have a serrated or cross-hatching pat-  tern of teeth for the beaks. This helps to grip the needle  securely without damaging it. A locking mechanism similar  to haemostats is present to lock the needle grasp.   The classical way to hold the instrument is to engage the  handle-rings with the thumb and the fourth finger. The mid-  dle finger is used for support and the index finger is used to  direct or orient the instrument in the required direction.  Alternatively, while suturing on tough tissues, one may be  “‘palmed’, i.e. may be held against the palm with fingers  around. While palming the needle holder, some surgeons still  rest the fourth finger lightly in the handle-ring.   The pickup forceps are used to delicately handle and manip-  ulate the wound edge which is being sutured. The fine-  toothed Adson forceps is the workhorse for most interior and  cutaneous wound closures. The forceps is held in the non-  dominant hand and is used to grasp, lift and evert the wound  edge so that the surface is made more amenable to a perpen-  dicular needle entry. Fine skin hooks may also be used for  the same purpose.   The suture cutting scissors is used to cut the suture thread  tags after the knot is tied. It is also used to cut the thread dur-  ing suture removal.    These scissors should be differentiated from scissors used  for cutting tissue. Many of them have specifically designed  blades and tips, which are uniquely shaped to lift and grasp  up the handing tags or the tied suture thread away from the  tissue and to cut it safely without injuring the tissues. Short  and long versions are available. The tip may be straight or  curved and may have a sharp slot for the thread to be cut.  Some manufacturers have incorporated a cutting component  in the needle holder itself, using which the surgeon can cut  the suture tag without switching instruments.    The suture needles help to pass the suture threads through  tissues. In ancient days, needles were made of natural mate-  rials such as bones, ivory, horns, wood or thorns. In fact,  eyed needles from as early as 30,000 AD have been  unearthed. Later, metals such as silver, copper and alumin-  ium bronze were used. The modern needles are diligently  shaped and contoured as per use and are smooth and strong  so that they withstand the stresses of suturing and least trau-  matic to tissues at the same time.   The suture needle has three parts: the tip, the body and the  suture attachment. Made of stainless steel or carbon steel,  they are thin, smooth and sharp, designed to pass through  tissues with ease (Fig. 11.1).    11.3.2.1 Needle Shape  The suture needles are usually curved as an arc of a circle.  Straight needles, though available, have very limited practi-  cal applications. The curvature is described as the span of the  arc, in terms of 14, 3/s, % and */s of a circle. Most of the regu-  lar suturing in oral and maxillofacial surgery is done with  half circle needles. A smaller arc such as */, can be used for  suturing flat skin surfaces. Longer arc, i.e. °/g circle, needles  are used in narrow tunnelled surgical fields such as in cleft  palate or inside the nose (Fig. 11.2).   The cross section and the tip of the needles can be widely  varied. Depending on these aspects, the suture needles can be.    Round bodied needles are generally used to suture viscera  and other internal structures such as muscle and fascia. It can  also be effective on non-keratinised mucosa. The tip of the  round-bodied needle can be blunt or sharp. The blunt tip  needle is specifically used in the inner abdominal wall and in  friable tissues. The sharp tip is used for most other purposes.  But even the sharp tip is hard to pass across the skin and  keratinised mucosa. The shape of the ‘cutting’ needle over-  comes this problem. In the cutting needles, the needle cross  section is a triangle, with the inner curve side being pointed    and the outer convex side flat. This shape enables the needle  to ‘cut’ through the dense tissues to make the needle passage  easier. But the cutting design presented a new problem. Even  under minimum tension, the needle behaved like a knife, and  the sharp edge often tended to lacerate the tissue resulting in  a ‘cut-through’ of the wound edge. This was solved by the  reverse-cutting design, wherein the inner curve is flat and the  outer curve is pointed. This helps to retain the cutting nature  while avoiding the risk of wound edge laceration. In oral and  maxillofacial surgery, the tissues encountered may be kera-  tinised (skin, gingiva and palate) or non-keratinised (buccal  mucosa, floor of mouth and lips). Mostly, reverse-cutting  needles are now being used since they are well-suited to pass  through all oral tissues without causing inadvertent tears.   The suture needle size generally depends on the size of the  suture. In general, smaller the suture size, smaller the needle.  It is important to recognise the various dimensions of a  needle.    The ‘needle length’ refers to the end-to-end measurement  along the curve of the needle. The straight line distance from  the tip to the other end is called ‘chord length’. The chord  length determines the bite-width of the needle in the tissues.  The bite-depth into the tissue is defined by the ‘chord diam-  eter’ which is perpendicular from the chord length to the  centre of the needle body. Needle diameter and needle radius  are dimensions which refer to the cross-sectional thickness  and not to the needle curve.   The eye of the needle is a small hole at one end for attaching  the suture thread. This necessitates an increase in the needle  thickness at the attachment end, increasing the risk of poten-  tial tissue trauma. The suture is passed through the eye, and  may then be tucked or tied for better retention. Both tucking  and tying further increases the tissue drag and causes addi-  tional trauma. The attached suture now follows the needle  through the tissues. The eyed needles are cheaper and can be  reused after resterilisation.   Modern suture needles do not have an eye. Instead, the  suture thread is sealed inside the needle for a permanent  attachment. This mechanism, called ‘swaging’, reduces the  tissue trauma significantly as the needle diameter is not  increased for thread attachment. Further, only a single thread  strand passes through the tissue at all times. So these needles  are often called “atraumatic needles’. The swaged needle with  thread is available as a sterile pack, and cannot be reused.    Many different types of suture threads are available for use.  Each type has its specific benefits and indications for appli-  cation (Table 11.1).   A basic classification divides them into ‘natural’ and  ‘synthetic’. Suture materials sourced from natural sources  include catgut, steel and silk. Synthetic plastic materials  such as nylon, polypropylene and polymers of glycolic acid,  lactic acid, etc., have become popular in recent decades.   Suture materials can also be classified as absorbable and  non-absorbable. Absorbable sutures hold the tissues together  till they have healed sufficiently to withstand normal stress,  and are then absorbed by the tissues where they are embed-    ded. Non-absorbable sutures, on the other hand, are not  absorbed, and they should be removed after the initial stabili-  sation of the wound edges has occurred. In reality, most or all  natural materials will get absorbed by the body in due course  of time. Thus, for clinical practice, a suture is considered  non-absorbable if it retains its tensile strength in tissues for  more than 60 days.   According to the filament type, the sutures may be mono-  filament or multifilament. A monofilament suture is essen-  tially a single strand of fibre. This simple structure enables  these sutures to pass through tissues with least resistance.  Though this makes it the material of choice in delicate tis-  sues such as the vascular tissues, there are some notable  drawbacks. The handling and knot-tying are generally more  taxing, and the knot has less friction to keep its position. In  addition, the cut edges tend to be stiff leading to probable  irritation of movable and delicate regions like the tongue and  buccal mucosa.   The multifilament sutures are made of multiple fibre  strands, which are either coated or braided together to make  one fine thread. The process of braiding bestows a higher ten-  sile strength as well as better pliability and flexibility. This  improves the handling characteristics and the ease of knot-  tying. They also better resist the tendency of the knot to untie  itself. The cut edges are usually smooth and soft, and are not  irritating to oral tissues. The disadvantages of multifilament  sutures include the higher risk of harbouring pathogens in its  structure and the tendency to ‘wick’ the oral fluids into deeper  tissues through the suture track. This, in turn, can lead to  occurrence to unaesthetic suture tracks visible on the skin.    The suture thread is available in different thicknesses. The  thickness is usually mentioned as ‘number of zeroes’. This  system follows the U.S. Pharmacopeia, and has gained wide  acceptance. The most commonly used thread size for intra-  oral use is mentioned as 3-0 or 000 size. Sutures are avail-  able from size 6 to 11-0 (Table 11.2).   . Stay inert in tissues without causing antigenicity or  other adverse tissue reaction.   USP designation 11-0 10-0 920) 8-0 7-0 6-0 510) 4-0 30) 20) 0 1 2 3  Diameter (mm) 0.01 0.02 0.03 0.04 0.05 0.07 0.1 0.15 0.2 0.3 (O35) 0.4 0.5 0.6    It is beyond the purview of this chapter to go into the details  of all the types of suture materials available in the market,  chemical structure, method of resorption, qualities, indica-  tions, advantages, etc. Details of few suture materials widely  used in oral and maxillofacial surgery are given below.    The absorbability characteristics of many natural materials  had been recognised for millennia. All absorbable natural  suture materials contain predominantly collagen. Over the  years, they have progressively fallen out of favour due to the  risk of antigenicity and adverse tissue reaction [1].    11.4.2.1 Catgut  Catgut has been the most popular material in this group. Its  use has been prevalent at least from the time of Galen of  Pergamon (200 AD). This material is made of tissue taken  from the submucosal layer of sheep intestine or from the  serosal (adventitial) layer of the cattle small intestine intima.  The collagen strands are twisted together and the resultant  thread is precision-ground to form a monofilament. Catgut  has long been a popular fibre to make string instruments and  tennis racquets. For many centuries, catgut (surgical gut) had  been the only absorbable suture material available. The  absorption is by proteolytic biodegradation brought about by  proteolytic enzymes.   Performance-wise, catgut has good flexibility but rela-  tively poor tensile strength, poor knot stability and high tis-  sue reactivity. Full tensile strength remains only for 7 days.   It has been found that many poor characteristics of catgut can  be overcome by impregnating the suture material with chro-  mic salts. This modified product, called chromic catgut, has  higher tensile strength and delayed absorption time. Chromic  catgut retains its maximum tensile strength for about  2 weeks. It also has reduced tissue reaction as compared to  plain gut.   Manufacturers package catgut sutures soaked in the disin-  fectant isopropyl alcohol solution to retain the flexibility and  to increase shelf life. This necessitates rinsing of the suture  in sterile saline to remove the irritant alcohol before use.  Some manufacturers use a glycerine coating on chromic cat-  gut to do away with the alcohol in packaging. Glycerine-    coated chromic gut is smoother and thicker and has better  handling characteristics.    These are the oldest suture materials known to mankind.  People tended to use any threaded material known to them  for holding the wound edges together. Non-absorbable natu-  ral materials include cotton, linen, steel and silk.    11.4.3.1 Cotton and Linen  Cotton and linen sutures primarily contain cellulose polymer.  Both the materials get absorbed in due course, but are consid-  ered non-absorbable because of delayed absorption time.  Cotton is sourced from the hair of the cotton seed while linen  is made from flax. The fibres are twisted to form a suture. It  has good tensile strength, but there is moderate tissue reac-  tion. Handling is average but knot-holding is good. Linen has  the advantage that it gains tensile strength when wet.   Cotton and linen have largely fallen out of favour because  of adverse tissue reactions and the high ‘wicking’ effect  which causes seepage of fluids into the suture track.   Silk has been a well-known textile material from fourth mil-  lennium BC. It is produced by the silkworm larvae to form  the cocoon. Natural silk is a protein fibre, the main compo-  nents being fibroin and sericin. Fibroin forms the basic struc-  ture and contributes to the tensile strength. Sericin is a gum  layer which holds the strands together. The silkworm larvae  are cultivated and once they start pupating, the cocoons are  dissolved in boiling water to extract the individual fibres  which are fed into the spinning reel. To make it suitable as a  medical product, the sericin protein component is later  removed by a degumming process.   Silk is the most widely used natural non-absorbable suture  material. Surgical silk is made from the larvae of the silk-  worm Bombyx Mori. The silk suture consists of a group of  strands braided around a core and has a wax or silicon coat-  ing. It is usually dyed black in colour for better visibility.   The most impressive property of the silk suture is the ease  of handling. It is extremely pliable and smooth and has good  knot-holding capability. But the tensile strength is pretty low.  The other drawbacks include high levels of tissue friction,  capillary action and tissue inflammatory response. The wax  coating helps to counteract all these negative attributes.    Silk is now not considered an appropriate material for  cutaneous suturing, except on specific sites such as eyelids  and lips. It is very often used for ligating blood vessels and  for hitching drains. It is the most popular material used in  dentistry. Its soft and pliable nature makes it suitable for use  in oral mucosa which is mobile and wet.    11.4.4.1 Polyamide/Nylon (Ethilon, Dermalon)  Nylon belongs to the first generation of commercially suc-  cessful synthetic thermoplastic polymers, having started pro-  duction in 1927. It is made of repeated units linked by  aliphatic or aromatic amide links (polyamide). It has been a  very versatile material and has been used as fabric, fibres,  films, coatings and moulded shapes for wide applications in  diverse fields.   Nylon surgical sutures were introduced in 1940.  Monofilament nylon sutures are very popular for cutaneous  suturing. The main advantages are their high tensile strength,  exceptional elasticity and low tissue reaction. The elasticity  helps the material to accommodate tissue swelling and main-  tain wound edge apposition. The nylon sutures are dyed  black in colour.   The biggest shortcoming of this material is its shape  memory, which negatively affects its knot-tying and knot-  holding properties. Often, one needs 3-4 knots to hold a  stitch in place. Also, the monofilament may be stiff.  Multifilament nylon sutures are available with increased pli-  ability and handling features. Addition of fluid (alcohol) in  the package reduces the shape memory and improves  pliability.    11.4.4.2 Polypropylene (Prolene, Surgipro)  Polypropylene is another thermoplastic polymer used as a  non-absorbable suture material. It is produced by chain-  growth polymerisation of the monomer propylene. It is pig-  mented blue to enhance visibility, hence the name  polypropylene blue.   Similar to nylon, polypropylene has a very high tensile  strength, excellent elasticity and minimal tissue reaction. It  can extend up to 30% without breakage, making it highly  suitable for suturing cutaneous wounds. The shape memory  is also similar to nylon and can contribute to knot slippage.  This feature, though, is advantageous in subcuticular sutur-  ing since it slides out smoothly during suture removal.   The excellent mechanical properties and inert nature  have made polypropylene the material of choice in stressful  sites. It is widely used in the management of hernia and  vaginal prolapse, often in the form of a mesh in addition to  sutures.    11.4.4.3 Polyester (Ethibond, Surgidac, Dacron)  Polyester is a general term used for any organic polymer  which has an ester functional group in the main chain. More  specifically, the term is used for the material polyethylene  terephthalate. It is a type of petroleum-based plastic, made  by mixing ethylene glycol and terephthalic acid. Because of  its durability, cleanability, anti-wrinkle and quick-drying  characteristics, it swiftly made a name in the textile industry  as a reliable material.   Polyester is a non-absorbable, braided, surgical suture  with high tensile strength and low tissue reactivity. The  braided nature adds to enhanced handling, knot-tying and  retentivity. Thus, it combines the positive features generally  attributed to monofilaments and multifilaments. It is thus the  suture of choice in cardiovascular surgery, prosthetic  implants and facelifts.   Polyester braided sutures are usually dyed green in colour.  They may be coated or uncoated. The uncoated variant has a  rough surface which produces drag in the tissues. The coat-  ing is made of PTFE or polybutylate.   Polybutester is a relatively new thermoplastic material with  unique stress-strain properties. It is a copolymer comprised  of polybutylene terephthalate and poly teramethylene ether  glycol, and is coated with polytribolate. The polybutester  monofilament sutures are designed to have high strength,  elasticity and pliability. The flexibility and lack of memory  allow it to be handled with ease resulting in a high knot secu-  rity. The unique features have made this a popular material  for abdominal wound closure.   The elasticity of polybutester is phenomenal. It can stretch  50% of its length at initial loads. It has a biphasic expansion  curve wherein it expands well in response to initial stress and  maintains pressure without cutting the tissue, and at the same  time withstanding creep by not undergoing permanent defor-  mation even under constant pressure.   Polytetrafluroethylene (PTFE) is a synthetic material which  has found extensive application globally. It is a fluoropoly-  mer of tetrafluoroethylene (-CF,-CF,-), made by free-radical  polymerisation of monomer units. PTFE is a strong, tough,  waxy, non-flammable material popular for its non-stick  properties.   PTFE suture is considered as the ideal material for oral  surgeries, especially for dental implant surgeries. It is  inert, non-absorbable and monofilament in nature. The  strong fluoro-carbon bond is thought to be the reason for  its inertness. Unlike other synthetic monofilament sutures,  PTFE is smooth, supple and soft. The cut ends cause no    irritation to delicate oral tissues. It has no shape memory.  It is well tolerated in the oral cavity and has excellent han-  dling, knot-tying and knot-holding abilities. Thus, it has  most of the positive attributes of braided sutures, at the  same time avoiding the risk of bacterial contamination by  wicking effect.   Surgical stainless steel non-absorbable surgical suture is  composed of 316 L austenitic stainless steel. It can be mono-  filamentous or multifilamentous. The obvious advantages of  stainless steel sutures are strength and low tissue reaction. Its  drawbacks include very poor flexibility that makes it highly  demanding in suturing skills. Incorrect technique can cause  an excessive pull or tear on the tissues resulting in necrosis of  wound edges. Barbs at the end can cause glove punctures and  trauma to adjacent tissues.   Stainless steel suture is used in sternal closure and in  orthopaedic procedures involving cartilage and tendon  repair. It is also sparingly used for abdominal wound closure  and hernia repair.    Till polyglycolic acid sutures were introduced in the 1970s,  all absorbable sutures were natural. The synthetic absorbable  sutures are all polymers based on glycolic acid, |-lactic acid,  paradioxanone, trimethylene carbonate and e-caprolactone  [2]. They are sterilised either by ethylene oxide gas or by  gamma radiation. These polymers have definite advantages  over chromic catgut in clinical use. They are much stronger,  evoke minimal tissue reaction, stay longer before absorption  and leave no reactive changes after they are resorbed. They  are absorbed typically by hydrolysis reaction which breaks  the polymer chains. The hydrolysis end products are CO),  H,O and the monomer.   Polyglycolic acid suture, introduced in the early 1970s, was  the first absorbable synthetic suture material. It is braided  homopolymer of glycolic acid. The uncoated version is beige  in colour while the polycaprolate-coated product may be  undyed or dyed green, violet or bicoloured. When compared  to catgut, the tensile strength and knot security are excellent.  It retains 65% of its tensile strength after 2 weeks, by which  time catgut would have lost all its strength.   The polylycolic acid soon became very popular but fell  out of favour later as better products were developed in due  course of time.    11.4.5.2 Polyglactin 910 (Vicryl, Polysorb)  Polyglactin 910 is a synthetic heteropolymer consisting of  90% glycolic acid and 10% lactic acid. Introduced in 1974,  this is a multifilamentous, braided suture with a lubricant  coating of polyglactin 370 (30:70 ratio) and calcium stearate.  The final product is usually dyed violet in colour, but an  undyed beige version is also available. Polyglactin 910 is  among the most popular absorbable sutures used for surgical  wound closure today.   The main advantages of polyglactin over polyglycolic  acid include consistently higher residual tensile strength and  faster absorption. The absorption happens between 40 and  70 days. The coating ensures smooth passage. Since the  coating is made of similar material, the risk of flaking is very  low. Calcium stearate used in the coating is an absorbable  organic lubricant. The shelf life of polyglactin is as high as  5 years.   As the material became very popular and widely used,  manufacturers began to bring out modified products pro-  viding specific benefits. One of them is a monofilament ver-  sion which does not require a coating. Another one is an  ‘antibacterial suture’ with embedded triclosan, which is  said to be very effective in preventing surgical site infec-  tions. Yet another useful modification is ‘rapidly absorbing  polyglactin’ (Vicryl Rapide/Velosorb Fast). By treating the  coating with y-radiation, it is made to lose strength by sec-  ond week and is fully absorbed by sixth week. This variant  is widely used in oral surgery, where faster resorption is  desired.    11.4.5.3 Polydioxanone (PDS, PDO)  Polydioxanone was the first monofilament suture available  of large size (larger than 3-0). It is a polyester product and is  synthesised through the ring opening of the monomer para-  dioxanone (1, 4-dioxan 2-one). As a monofilament suture, it  has much less drag through the tissues than polyglactin or  polyglycolic acid. Since it retains its tensile strength over a  long span of time (80% strength at 2 weeks and 60% after  6 weeks), it is considered a better alternative to polyglactin  for suturing of fascia.   A modification called PDS II is chemically similar but is  annealed above melting temperature to soften the external  surface, imparting improved flexibility to the final product.   Often seen as the monofilament alternative to polyglactin,  poliglecaprone is a segmented block polymer consisting of  75% glycolide and 25% e-caprolactone. It is available as an  undyed or a violet dyed version. The key feature that differ-  entiates poliglecaprone from other monofilament sutures is  the high level of pliability and handling properties. This is    achieved through the formation of an interim soft polymer  chain ‘pre-polymer’ which is high in caprolactone. In the  ensuing stages of manufacturing, more glycolide is added to  supplement hard segments to the pre-polymer. In this way,  we get a final product with high tensile strength without  compromising on the pliability.   The tensile strength of the undyed poliglecaprone suture  degrades to 50% in | week and 30% in the second week. The  dyed version retains 70% strength after 1 week. Complete  absorption by hydrolysis happens in about 100 days.   This copolymer has a molar ratio of 64% glycolic acid and  36% trimethylene carbonate. It is an uncoated monofilament  which may be undyed or dyed dark green. Polyglyconate has  good handling properties. But its main advantage is the  retention of tensile strength over a long time span. It retains  at least 50% of its strength 4 weeks after implantation, mak-  ing this an excellent choice in situations where long-term  retention is needed. The slow absorption makes it relatively  unsuitable for subcuticular sutures, since the dyed suture  may be visible under the surface.    11.4.5.6 Glycomer 631 (Biosyn)  It is a synthetic absorbable coated monofilament polyester  suture. It is a tri-block copolymer and contains glycolide  (60%), trimethylene carbonate (26%) and p-dioxanone  (14%). It may be undyed or dyed violet. It has high flexibil-  ity, low memory and minimal tissue reactivity.   It passes through the tissues easily but has poor knot-  holding capability. Degradation and absorption are similar to  polyglactin. Full absorption is complete in around 100 days.    11.4.5.7 Polyglytone 6211 (Caprosyn)  Polyglytone 6211 is the only suture available with four dif-  ferent monomers in its core structure. It is a polyester copo-  lymer of glycolide, caprolactone, trimethylene carbonate and  lactide in the ratio 6:2:1:1. It is a monofilament, uncoated,  absorbable suture which is undyed or dyed violet.  Polyglytone 6211 is a suture for the short-term approxi-  mation of tissues. Because of its quick disintegration, it  offers an inert alternative to catgut that can evoke inflamma-  tory response. Its strength decreases to 50-60% at 5 days and  to 20-30% at 10 days post-implantation.    The suture knot-tying can be accomplished by using an  instrument (usually the needle holder) or using hands. Three  main techniques are described.    The two-handed tie is cumbersome and is not routinely used.  The suture is tied together by holding one tag in each hand  and intertwining them.    The one-handed tie is the most popular hand-tie method. It is  quicker and can be accomplished in a smaller space. One end  of the suture thread tag (‘the long end’) is held with thumb  and forefinger of the dominant hand. The other side tag (‘the  short end’) is placed a bit distal to the first tag, running in the  same direction. The middle finger is folded and is used to  guide the short end around the long end, and then the two  tags are pulled away.    Instrument tie is the most popular technique for tying a  suture knot. The long end is wrapped around the needle  holder. Then the needle holder beaks are opened to grasp the  short end, which is then pulled to form a tie. One such tie is  called a ‘throw’.    The suture thread tags are intertwined to form a knot. The  knot should be firm and tight, and should not lie on the  wound/incision line. It is important that the knot stays tight  and maintains strength during the healing phase. Knot slip-  page or breakage before healing can be detrimental to the  wound. In general, knot security is higher for braided and  uncoated sutures because of higher friction coefficient.   The knots placed for the surgical suturing are of simple  design. Those employed commonly are the square knot, sur-  geon’s knot and granny’s knot. These three variants are very  similar to each other and differ from each other only in minor  aspects.    A square knot is among the simplest of the knot designs. It  involves a simple intertwining of the two threads. This ‘half-  hitch’ knot (one ‘throw’ around the instrument) need to be  complemented with an additional similar throw to make it  secure. Preferably the second hitch should be in the opposite    direction, i.e. if the first throw is in clockwise direction, the  second one should be in anticlockwise orientation.   The classical square knot formed by a clockwise and a  counterclockwise hitch can be further complimented by  more similar hitches in alternatively changing directions.    A surgeon’s knot is a minor modification of the square knot  in which the initial intertwining is doubled. This is accom-  plished by doubling the first throw, by doing two turns of the  thread around the instrument. This is followed by a regular  second throw in the opposite direction.    In the granny’s knot, two initial throws are placed in the  same direction, followed by a third throw in the opposite  direction.   Regardless of the specific technique, some basic prin-  ciples are to be followed while performing a suturing  procedure. It is to be remembered that these are only  general principles, and can be modified or rejected in  specific situations depending on the clinical context.    1. The suture needle is to be held with the needle  holder about 34" of the distance from the needle  tip.   2. The selected suture size should be the smallest  possible which will hold the wound edges securely.   3. The needle tip should enter the tissue perpendicu-  lar to the tissue surface.   4. The needle penetrations should be at equal dis-  tances from the wound edge on both sides of the  wound. The actual distance depends on the suture/  needle size but is generally agreed to be 2-3 mm.   5. The passage of the needle through the tissues  should follow the curvature of the needle.   6. When one side of the wound is fixed to the under-  lying tissues, one should first engage the mobile  wound edge.   7. When one side of the wound is thicker than the  other, the thinner wound edge should be engaged  first.    8. When one side is deeper and the other more super-  ficial, the deeper side should be engaged first.   9. The depth of needle penetration should be more  than the distance from wound edge to needle pen-  etration point. This will ensure eversion of wound  edges.   10. The sutures should ensure proper tissue approxima-  tion of wound edges at the same time avoiding  excessive tension on the tissues. Excessive tissue  tension can lead to blanching, tear and necrosis. In  case the edges are not approximating passively, the  flaps may be undermined to achieve better mobili-  sation so that a tension-free closure can be achieved.   11. The knot should lie on one side of the wound, and  not over the wound edges.   12. The spacing between the individual sutures  depends on the type of tissue and the size of  sutures. Generally placed 3-4 mm apart, they  should be closer together at areas of underlying  muscular activity and when the sutures are smaller  in size.    There are quite a large number of techniques available to  stitch a wound. Only the commonly used methods are  mentioned.    A simple interrupted suture (‘simple loop’) is the most com-  mon method to suture a wound. This is the simplest design  of wound closure. The suture passes once through each side  of the wound in a simple loop and is then tied in a knot    above the surface. Multiple such ties are made over the  length of the wound, resulting in several independent sutures  collectively securing the tissue edges together. The same  technique is frequently employed for internal suturing of  tissue layers also [4].   The needle penetrates the surface 2-3 mms away from the  wound edge on one side and proceeds into the subcutaneous  tissue. The curve of the needle is then used to pass it through  to the subcutaneous tissue on the opposite side. The needle  then exits through the surface. The initial and final tags, now  outside of the tissues, are then tied in a knot. The configura-  tion inside the tissue is thus in the form of a loop. If the  wound sides are of unequal depth, then the needle should  travel deeper in the lower side while staying superficial on  the higher side. This will help to correct the depth disparity  and ensure proper surface levelling.   This technique is easy to learn and employ. This suture  provides good tensile strength and carries minimal risk of  wound oedema or impaired circulation. Several adjust-  ments to the design are possible with this method depend-  ing on the wound characteristics. Since there is a series of  multiple sutures, even if one suture fails, the others may  provide sufficient strength to keep the wound edges together  (Fig. 11.4).   The major drawback of this method of suturing is the high  possibility of ‘rail-road track’ shaped scars caused due to the  ingrowth of epithelium into the suture tracks. There is also a  tendency to cause ‘wound inversion’ (depression of the  surface at the wound site) due to tissue contracture during  healing. The inversion can be prevented by making the suture  configuration ‘flask-shaped’ inside the tissues, by making  the needle travel farther laterally away from the wound  within the tissues. When compared to continuous suturing    techniques, the interrupted method is more time-consuming  as it requires many more knots need to be tied.    The buried suture is a modification of the simple interrupted  suture and is reserved for stitching the inner (deeper) tissue  layers. The only difference is that the knot ends up in the tis-  sues deeper to the suture loop, 1.e. away from the surface. In  essence, this is a simple interrupted suture in the reverse  orientation.   The wound edge is first reflected using fine forceps or  hooks. The needle is then inserted into the underside of the  dermis on one side. The needle then proceeds along its cur-  vature to exit in the wound edge more superficial to the initial  bite. The needle then pierces the dermis wound edge (near  the surface) on the opposite side, proceeds in a path mirror-  ing its motion in the first side and comes out at a deeper point  which corresponds to the first bite. Though the tie is done  outside, the knot gets buried deep inside the tissues as it is  tightened (Fig. 11.5).   This technique is extremely useful in suturing the inner  tissue layers before the surface closure. As the knot is buried  deep, it does not interfere with the closure of superficial lay-  ers. This aspect is extremely useful while closing cutaneous  facial wounds.   Two major drawbacks have been observed with this  suture. One is a skin dimpling which typically happens if the  suture arc inadvertently involves the epidermis. Another  problem is the tendency for wound inversion to occur. Small  modifications such a set-back dermal buried suture or a verti-  cal mattress buried suture can be employed to overcome this    problem. These modifications attempt to pass the bridging  suture segments to be deeper, thus resulting in wound  eversion.    The vertical mattress suture is in part similar to simple inter-  rupted sutures but includes an additional suture bridge close  to the wound edge. Also known as Donati Suture, or ‘far-far,  near-near’ suture, this is the most frequently used suturing  technique to obtain wound eversion [5]. This suture design is  very popular in abdominal and limb surgeries.   The needle is first penetrated far from the wound edge  (about 6 mm), and then proceeds through the deeper tissue to  the opposite side and emerges out at an equal distance from  the edge. The needle is then reinserted at a point closer  (2-3 mm) to the wound edge on the second side itself. It is  then rotated superficially through the tissues and is exited on  the other side at a corresponding near point. This results in a  double bridging of the wound, one deep in the tissues and    another superficial and nearer to the wound edge. Thus, both  tags of the thread are now on one side of the wound. They are  tied together gently (Fig. 11.6).   The primary advantage of this suture is the resultant  wound eversion. This eversion is expected to compensate for  the anticipated contracture occurring along the wound mar-  gin. As the suture is bridging the wound twice, the binding  strength is more. Elimination of dead space is another  obvious advantage. The suture thread does not pass the  wound edge on the surface, minimising the chance of track  marks.   On the flip side, fine wound edge approximation is almost  never achieved with this suture. Excessive tightening could  lead to over-constriction and sometimes exposure of the raw  area. This may necessitate placement of additional inter-  rupted sutures for better results.   The vertical mattress concept can be used in a buried  suture situation also by ensuring that the more superficial  suture thread passed back to the first side in a path parallel to  the first, deeper suture bridge. This will result in a better  wound eversion.    Simple continuous suture (‘running loop’, “standard running  suture’) is a good method for rapid closure of small wounds.  It gives an even distribution of tension all along the wound  span. It combines many benefits of the simple interrupted  sutures with the additional advantage of a quicker finish.   The technique is very simple. The first part follows the  same process as a simple interrupted suture. The first knot  becomes the anchoring knot for the ensuing running line.  The tags are not cut and the longer tag (with the needle) is  used for making the remaining loops. The needle is inserted  back into the tissues a few millimetres away from the first  piercing. Then the needle (followed by the thread) passes  through the tissues in a path parallel to the first loop. Once it  comes out of the second loop, it is not tied. Instead, the loop  is tightened and the thread crosses over obliquely across the  wound and enters the tissue surface again, a few millimetres  away from the second piercing. This process continues over  and over until one reaches the other end of the wound. As the  last loop goes through the tissues, the thread is only partially  pulled through, leaving some loose thread on the opposite  side. The suture is then tied to this loose thread for the final  knot. Thus, the suture material runs across the wound in  repetitive loops, and there are only two knots—one at either  end (Fig. 11.7).   The obvious advantages of this technique are the quick-  ness of suture placement and the ease of avoiding many  knots. Also, if the tissue wells up in one site, the remaining  part of the suture can provide some compensatory slack.   The principal drawback is that the integrity of the entire  suture line is vested in just two knots. Any breakage to the  suture at any point leads to the entire line getting untied.  Since the loops are in continuous succession, fine-tuning of  design for each loop is not possible. Also, since the tension is    the same across all loops, the areas of the wound with greater  tension, usually the central part, may tend to gape.    This is a variation of the simple continuous suture technique  used for surface wounds. Each loop of the continuous suture  is ‘locked’ on itself before making the next loop. This is the  most popular continuous suturing technique especially for  closing wounds over long spans. As with other superficial  continuous sutures, this method is frequently used as a sur-  face layer after the internal tissue layers have been closed.   Similar to the simple continuous technique, the first loop  is passed and the knot tied. After the second loop has gone  through the tissues and exited, the suture is not immediately  tightened. The needle and the leading thread it is made to  pass through the earlier loop. After making this ‘lock’, the  suture is tightened and is then passed into the tissues for the  third loop. The assistant should maintain this tension until  the next loop is passed. This process is repeated for the entire  line of succeeding loops (Fig. 11.8).   The locking helps to align the tissues in a proper anatomic  orientation perpendicular to the wound. There is an added  haemostatic effect due to the tension on tissues. Uniform  degree of tension is maintained across all the loops. At the  same time, the running locks partially detach the tension on  the individual loops from one another. Thus, to an extent,  individual control of tension depending on the site can be  obtained.   This technique inherits the main disadvantage of the sim-  ple continuous sutures of being dependent on only two knots,  and the risk of complete loss of suture integrity in case of  breakage at any point. The locks, if they are too tight, may  cause vascular compromise of underlying tissues.    This is a mostly buried, continuous, epidermal wound clo-  sure which is used for surface closure. The suture ends exit a  few mms away from the wound corner. The subcuticular  suture is employed only after the deeper structures and der-  mis have been secured well with absorbable sutures. It is  popular as an aesthetic suture for face [6].   The suture may be absorbable or non-absorbable, and is  usually thin (size 5—O or 6-0). The needle insertion is at one  end of the wound, 2-5 mm away from the apex. It is passed  along the curve into the wound, where it exits in the interior,  close to the apex. Then the needle is inserted again into the  dermis on any one side of the wound edge walls. Thereafter,  it passes horizontally parallel to the surface, and following  the needle curve to come out into the wound interior a small  distance away. The same step is then repeated on the other  side of the wound. This process is repeated till one reaches  the other end of the wound, wherein the needle is made to    pierce the far end apex and to come out in the surface. This  last step is a mirror image of the initial steps. Then each of  the suture tags on both sides is tied separately on to itself.  Alternatively, the tags may be secured with adhesive strips,  surgical tape or tissue glue (Figs. 11.9 and 11.10).   The biggest advantage of this technique is the much  decreased risk of scars. The close approximation achieved in  the dermis region makes the need for a further surface  suturing unnecessary. The tension is aligned centrally across  the wound and is evenly distributed all along the length of  the suture. Also, this technique is highly suitable in cases  where the suture material is required to stay in place for a  long period of time.   On the negative side, the subcuticular suture takes longer  time to perform. Leaving a large quantity of foreign material  in situ can increase the risk of foreign body reaction and  infection. If non-absorbable material is used, there is a minor  risk of long and thin suture track following removal. If  absorbable material is used, an undyed suture should be cho-    leave small segments of exposed raw area, which need to be  addressed with additional surface sutures.    This is essentially a modification of the simple continuous  suture, and is designed to reduce the size of a two-dimen-  sional surface defect. It is not a cosmetically superior tech-  nique and is rarely used in the face. The purse-string effect  causes a puckering in the surrounding skin tissue. But this is  an effective method to reduce wound area. It may also be  used to achieve haemostasis.    Fig. 11.10 Subcuticular suture at the subciliary incision site and at the  pre-existing lateral orbital laceration in a case of zygomatic complex  fracture fixation    At first, the wound edges of the defect need to be fresh-  ened and underlined. The needle and thread is passed along  the edge of the defect in a course running parallel to the  wound edge. Thereafter, it continues in a series of loops run-  ning along the edge of the surface wound along its entire  circumference. As the thread completes the full distance and  reaches near the initial needle entry, it is pulled taut, leading  to complete or partial closure of the wound. Then the tags are  tied together.    Also known as ‘tip stitch’ or ‘half-buried horizontal mattress  suture’, this technique is used for managing a situation where  three ends of the tissue have to be sutured together. In maxil-  lofacial surgery, this situation is encountered while repairing  V-shaped lacerations and while closing flaps with sharp cor-  ners (such as the triangular flap at the vermilion border for  cleft lip repair)   This suture is placed only after the flaps are brought into  position using buried dermal sutures. The surface suture  thread is used, that is, 6-0 for face and 3-0 for scalp. The  needle is first inserted into one side of the non-flap side of the  wound. It follows the needle curve to exit in the inner aspect  of the wound. The next tissue insertion is into the superficial  dermis of the flap tip. Then the needle passes horizontally  and comes out through the dermis on the other side of the  flap tip. After releasing from the flap tip, it re-enters the der-  mis of the non-flap side on the other side and comes out  through the skin at a point corresponding to the initial entry.  The tags are then knotted together (Figs. 11.11 and 11.12).    The Frost suture is a temporary eyelid suspension suture,  used to ensure proper lower eyelid placement during the  post-operative period [7].   After the closure of the lower eyelid incision, a needle  bite is taken on the tarsal plate or just inferior to it. Then a  second bite is taken just above the eyebrow, ensuring the  anatomic position and alignment of the lower lid. These tags  are then tied or secured with tapes or tissue glue (Fig. 11.13).   These sutures may be removed on third post-operative  day, but need to be kept longer if there has been significant  trauma to the tissues.    Different types of drains are used in surgery, such as corru-  gated rubber drain, the suction drain, intercostal drain, etc.  After the drain has been inserted, it needs to be securely  fixed to the body to prevent displacement.   The most common means to secure drains is the Roman  Garter method, which uses silk sutures. A strong bite is first  taken on the skin near the drain entry site. After making a  knot, the two suture tags go around the drain tube in a series  of windings. A knot may be tied after each 2 or 3 turns around  the tube. The large number of windings around the tube  increases the friction, holding the tube in position without  dislodgement (Fig. 11.14).   Other techniques which have been described include the  use of nylon suture, safety pin, drain clip, adhesives and  Tie-lok.    The tissues and the surgical environment in the dentoalveolar  region are different from other parts of the body.  Consequently, the wound closure requirements also differ.  Wound closure in dentoalveolar surgery involves suturing in  situations such as    1. Suturing of buccal and/or lingual flaps back to its place  after dentoalveolar surgery around teeth or implant  accessories.    In most cases, the needle passage is through keratinised  mucosa with little or no subcutaneous tissue, obviating the  need for multilayered closure. The presence of teeth or artifi-  cial crown on one side of the flap forces the surgeon to inno-  vate on the basic suture design. Another difference is when  the extraction wound is closed—the wound is usually closed  only at the edges and is largely left open in the middle. Also,  the suture site will have to endure itself in a challenging envi-  ronment with the presence of saliva, food materials and a  very dynamic milieu where tongue movements and mastica-  tory forces abound [8].   If marginal gingiva is not involved in the flap (as in a  semilunar flap), the wound closure models are usually not  different from the general cutaneous designs which were dis-  cussed in the previous section.    As in any case of wound closure, the simple interrupted  suture is the mainstay in closing dentoalveolar flaps [9]. In  general, it involves suturing the detached interdental papillae  together. The needle passes from the buccal aspect of the  buccal flap, emerges on the inside of the flap and then passes  between the tooth roots to enter the inner aspect of the lin-    gual flap. As it pierces the lingual flap and emerges through  the mucosa, the needle is turned back and is taken back via  the interdental region to the buccal side. The two suture tags  are then tied together. Thus, the knot remains on the buccal  side and is accessible for removal.   If only one flap (usually buccal) has been raised, the nee-  dle can still pass through the attached lingual flap and the  suture design stays the same. In post-extraction wounds also,  the procedure is the same, and the tooth socket space is not  totally closed.    In this modified interrupted suture, the direction of the nee-  dle is reversed for engaging the lingual papilla. Once it  passes through the buccal papilla and reaches the lingual  side, the needle orientation is reversed and it is made to enter  the lingual papilla from outside (lingual side). The needle  exits the flap on the inside, passed across to the buccal side  and is then tied. Thus, both the papillae are engaged in an  ‘outside-to-inside’ orientation, ending in a figure-of-eight  formation in the vertical plane (Fig. 11.15).   This technique is especially useful in cases where both  buccal and lingual flaps are raised during surgery, such as in  periodontal surgeries.    Vertical mattress technique in dentoalveolar surgery is a  modification of the papilla-attaching simple interrupted  technique. After the initial passage of the needle through the  buccal and lingual papillae, the needle is turned back and  picks a small bite at the tip of the lingual papilla before pass-  ing back to the buccal side. Then it again pierces the tip of  buccal papilla before knot-tying.   While this technique helps in pressing the papilla into  the interdental space, it is not a popular technique because  of the difficulty in getting a solid bite at the papilla tip with-  out ‘cutting through’. Obviously, one needs to use an atrau-  matic needle with a small thread (4—0 or smaller) for this  purpose.    This is a two-dimensional suturing technique where the  suture thread is spread in a horizontal fashion in the tissues.  It is not very popular for general cutaneous suturing but is  especially useful in dentoalveolar surgery.   When closing flaps in edentulous areas, the needle first  passes through both flaps. Then it is reinserted into the flap  on the same side, a little distance away from the earlier exit  point. The reinserted needle now passes through both flaps  and emerges out a similar distance away from the initial  entry point. Both the thread tags, now on the same side, are  tied together (Fig. 11.16).   In dentulous areas, this technique sutures two adjacent  papillae together, eventually tying four papillae segments  around a tooth in a horizontal square fashion. To close extrac-  tion wounds, only the papillae are approximated and the  tooth socket space is not closed completely.   The advantage of this technique is that a single horizontal  mattress suture serves like two separate interrupted sutures,  thus helping to reduce the number of sutures. It compresses  the wound from four corners and helps in haemostasis. It  also results in some degree of wound eversion.    In this modification, the suture does not pass through the lin-  gual soft tissues. After passing through the buccal papilla,  the suture passes through the interdental region into the lin-  gual side. Without engaging the lingual papilla, it goes  around the tooth and comes back to the buccal side via the  interdental space on the other side. Then it engages the buc-  cal papilla before being tied. In this way, it secures the papilla  to the bone using the tooth as its ‘anchor’.   This technique can also be used in a reversing fashion,  where only the papilla on the lingual side is engaged and the  buccal side papillae are not pierced.    This technique attempts to combine the benefits of vertical  mattress suture with those of horizontal mattress suture. The  basic technique goes similar to the horizontal mattress but  the final tag re-enters the buccal papilla at the tip and tra-  verses a reverse path around the tooth to exit near the initial  entry. In this way, it ensures the engagement of both buccal  papillae in a vertical mattress fashion.    The figure-of-eight suture is the most popular modification  of the horizontal mattress technique. This is used mostly in  closure of extraction wounds, and never in the presence of  teeth at the wound site.   The needle first penetrates the buccal papilla on one side  and then the lingual papilla. Then the thread crosses across  the edentulous site, and the needle is reversed in orientation  to pierce the buccal papilla of the other side from outside    (buccal side) to pass through the lingual papilla and exit on  lingual side. Then the thread passes across the site to be tied  with the initial tag. The suture thus ends with the appearance  of suture material crossing the wound site in a ‘cross’ shape  (Fig. 11.17).   Many surgeons consider the figure-of-eight suture to be  the most comprehensive way to suture a single tooth extrac-  tion site. This method ensures an even tension on the tis-  sues from four corners, effectively constricting the wound.  There is a positive effect on haemostasis also, due to the  tension on the flap and due to its presence a mechanical  barrier to clot loss.    The continuous sutures are almost exclusively used for eden-  tulous situations including post-extraction closure. After  making a conventional interrupted suture knot, the longer tag  is not cut and is instead used to make a series of ‘running  loops’ approximating the succeeding pair of papillae one  after the other. Gentle tension must be maintained on the  thread to keep the loops tight while the needle passes through  the next tissue. Knots are not tied for each loop but is done  only at the other end of the long wound. Some surgeons pre-  fer to tie a knot after 3 or 4 running loops. In the end, the part  of the suture passing through the inner tissues are perpen-  dicular to the wound, and the superficial, exposed parts lie  across the wound in an oblique fashion.   The continuous sutures save time and effort while closing  wounds of long span. It also ensures an even distribution of  tension across the wound. The obvious disadvantage is the  fact that if one loop or part of the suture is compromised (by    untying, cutting through or loosening), the entire suture line  gets loosened.    The continuous locking suture is a continuous suture in  which a ‘lock’ is incorporated by passing the thread under  the previous loop before it is pulled through the tissue. It is  important to keep maintaining the tension on the previous  loops as the needle makes the next pass through the tissue  (Fig. 11.18).    This technique ensures a better orientation of the sutures  with respect to the wound. The superficial, exposed parts of  the suture are oriented perpendicular to the wound, leading  to better anatomic wound approximation.    Non-absorbable sutures on skin and mucosa should be  removed after the wound surface has achieved initial stabil-  ity. The timing of suture removal is very important. They  should remain in tissue long enough to prevent dehiscence  and scar spread. On the other hand, early removal reduces  tissue reaction and suture marks.   Sutures on facial skin and in oral cavity are usually  removed in 5—7 days. The recommended interval is 3—5 days  for eyelids, 7 days for neck and 7-10 days for scalp. Those  on trunk and limbs should remain in place for 10-14 days.   The suture line is cleansed with antiseptic. The knot is  grasped and is pulled away mildly from the surface and to  one side of the wound. An uncontaminated segment of the  thread is exposed on the other side by this pull. The thread is  cut at this segment near to the surface. Then the suture is  pulled out, making sure that no contaminated (exposed) part  is ragged through the tissues.   In the case of a continuous suture, every single loop  should be cut and pulled out separately. A subcuticular suture  is removed by cutting the knot off at any one end, and then  pulling the suture out gently from the other end. It is impor-  tant to make sure that the suture does not break within the  tissues.    The use of specialised staples for wound closure was pop-  ularized in 1900s by the Hungarian surgeon Hiimér Hiiltl,  known as the ‘father of surgical stapling’. Compared to  suturing, surgical stapling is a quicker method to close the  skin in large wounds, and the inflammatory response is  relatively less. Staples provide good wound edge eversion  without strangulation of the tissue. It is an excellent  method to employ in cases which require quick wound  closure and where aesthesis is not a major concern [10]  (Fig. 11.19).   Though titanium staples were initially used, almost all of  the contemporary hardware is stainless steel. However, tita-  nium retains the advantages of being biocompatible and  MRI-compatible. Bioresorbable staples, based on polygly-  colic acid, are also available. The stapler devise itself may be  of stainless steel (reusable) or plastic (disposable), into  which the disposable staple cartridges can be loaded.    In maxillofacial surgery, staples are frequently used to  close scalp wounds and neck incisions, following the closure  of internal layers with conventional sutures. Staples are also  popular in reconstructive surgery to secure skin grafts and to  close the flap donor sites. They are not generally used to  close facial wounds, since there is a tendency to produce  ‘rail-road track’ scars. Skin staples are removed after 7-10  days with a specialized staple remover device.    Different types of surgical adhesive tapes are used to effect  wound closure, to reduce tension on sutured wounds and to  reinforce wound site after suture removal.   The indications of this method for wound closure per se  are limited. Tapes can be used to close superficial lacerations  where tissue tension is minimal. They are also employed in  the closure of superficial layer after buried dermal sutures  have been employed for wound edge approximation and ten-  sion reduction. A major indication is its use an additional  reinforcement and protection over sutured wounds. The  advantages of using tapes for wound closure are.   (b) The tape application is painless (patient anxiety  and discomfort are minimal).   (d) There is no need for a review visit to remove the  tape.   (e) Tapes, being non-invasive, are less prone to infec-  tion than other methods.   (f) They are suitable for thin, fragile skin of the  elderly and infants.    On the other hand, there are significant limitations to the  use of tapes to close wounds. The most obvious contraindi-  cation is an area under significant tension. Tapes are difficult  to apply on to highly convex surfaces, irregular wounds and  in areas of tissue laxity. They do not attach well to wet sur-  faces (e.g. oral mucosa). They may get detached easily in  hairy areas and those which tend to sweat.   These tapes are typically made of synthetic reinforced  material with a hypoallergenic adhesive and are made porous  to make them ‘breathable’ for skin. Some products are made  elastic to account for oedema tension while some have incor-  porated antibiotic to reduce the incidence of surgical site  infection. Modifications of tape-based wound closure include  incorporation of a zip-lock mechanism and a clip attach-  ment, both techniques designed to pull the wound edges  together for better approximation.    The use of tissue adhesives is an efficient way to close  wounds in select cases. Just like surgical tapes, tissue adhe-  sives can be used to approximate wounds that do not require  deep-layer closure and do not have significant tension on the  edges [11].   All currently available tissue adhesives are chemically  cyanoacrylates (esters of cyanoacrylic acid). These com-  pounds were discovered by Ardis in 1949 and were first  used in surgery by Coover in 1959. These are chemically  similar to methacrylates, the only difference being the  methyl (CH;) group substituted with cyano/nitrile (CN)  group. The water present on the skin or mucosal surface  activates the acryl groups in the resin to rapidly polymer-  ise and form long, strong chains. Three types of tissue  adhesives are currently available for clinical use—2-octyl  cyanoacrylate, N-butyl-2-cyanoacrylate and isoamyl  2-cyanoacrylate. The adhesion involves two mecha-  nisms—mechanical interlocking into the surface irregu-  larities and chemical covalent bonding with the  nucleophilic amine groups on skin surfaces.   Tissue adhesives are mainly used to treat superficial skin  tears (that do not extend past the dermis) and for surface clo-  sure after the deeper layers are secured with sutures. Other  indications include stabilisation of bone fragments during  plating, sealing of CSF leaks and sinus perforations, attach-  ing grafts, achieving peripheral nerve reanastomosis and clo-  sure of dentoalveolar flaps [12]. They are also widely used to  achieve haemostasis at surgical sites and as a biologic cover  on ulcers. The relative contraindications include wounds  over or near joints and wounds under significant static or  dynamic skin tension. Also animal bite wounds, crushed  wounds and wounds in high friction areas and those with   The procedure for using the tissue adhesives for surface  closure involves thorough cleaning and haemostasis. Though  moisture is a prerequisite for adhesion, the presence of  excessive water or blood at the site is detrimental to a good  result. The surface is dried before applying the adhesive in at  least three to four thin layers along the length of the wound’s  surface. It is advisable to extend it approximately 5-10 mm  from each side of the wound. The edges of the wound are  held together for at least 1 minute as the adhesive dries.   The main advantages of tissue adhesives over other  wound closure methods are the rapidity and painless applica-  tion [13]. In addition, the suture track scars are avoided, lead-  ing to a much better cosmetic result. The risk of suture site  infection is also found to be less. The material sloughs off in  5-10 days, as the skin sheds.   The obvious disadvantage is that it cannot be used in  areas of tension. Additionally, there is a minor risk of toxic-  ity and foreign body reactions. If the clinician’s gloved fin-  gers, gauze or plastic instruments contact the tissue adhesive  during application, these materials may adhere to the  patient’s skin.    Wound care primarily involves measures to ensure that the  wound heals quickly without going through adverse situa-  tions such as infections. Along with mechanical debride-  ment, antibiotic medication and dressings, the various wound  closure methods form the foundation of wound care prac-  tices. Depending on the patient needs and the wound types,  one should choose from a wide variety of materials and tech-  niques to implement effective wound closure.    1. Buckley MJ, Keller JC. Emerging biomaterials and tissue engineer-  ing. Oral Maxillofac Surg Clin North Am. 2002 Feb;14(1):ix.   2. Herford AS, Haug RH. Emerging biomaterials and tech-  niques in tissue regeneration. Oral Maxillofac Surg Clin N Am.  2017;29(1):1-120.   3. Kandor J. Atlas of suturing techniques. Approaches to surgical  wound, laceration, and cosmetic repair. New York: McGraw-Hill;  2016.   4. Hupp JR. Guide to suturing. Section 2. J Oral Maxfac Surg. Aug  2015;73(Suppl 1):9-35.   5. Kudur MH, Pai SB, Sripathi H, Prabhu S. Sutures and suturing  techniques in skin closure. Indian J Dermatol Venereol Leprol.  2009;75(4):425—34.   6. Gusman DN. Suture materials and techniques. In: Lower extrem-  ity soft tissue and cutaneous plastic surgery, vol. |. Nottingham:  Saunders; 2012. p. 77-100.    11 Wound Closure and Care in Oral and Maxillofacial Surgery 237  7. Connolly KL, Albertini JG, Miller CJ, Ozog DM. The suspension 11. Tuptis A, Salma I. Fibrin sealant in maxillofacial surgery (litera-  (frost) suture: experience and applications. Dermatol Surg. 2015 ture review). https://www.rsu.lv/en/scientific-papers/fibrin-sealant-  Mar;41(3):406-10. maxillofacial-surgery-literature-review. 2015.  8. Koshak HH. Dental suturing materials and techniques. Glob J 12. Kaderi MA, Menaka KB, Metgud RM, Gharat MR, Naik PS,  Otolaryngol. 2017;12(2):1-11. GJO.MS.ID.555833 Ajmani JM, et al. In-vitro evaluation of antibacterial potential of  9. Griffin TJ, Hur Y, Bu J. Basic suture techniques for oral mucosa. cyanoacrylate tissue for intra-oral wound closure. J Dent Mater  Clin Adv Periodontics. 2011, Nov;1(3):221-32. Tech. Sep 2017;6(4):163-9.  10. Iavazzo C, Gkegkes ID, Vouloumanou EK, Mamais I, Peppas G, 13. Oladega AA, James O, Adeyemo WL. Cyanoacrylate tissue adhe-    Fallagas ME. Sutures versus staples for the management of surgical  wounds: a meta-analysis of randomized controlled trials. Am Surg.  Sept 2011;77(9):1206-21.    sive or silk suture for closure of surgical wound following removal  of an impacted mandibular third molar: a randomized controlled  study. J Craniomaxillofac Surg. 2019 Jan;47(1):93-98.    Open Access This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.  org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropri-  ate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.   The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in  a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.    Postoperative care of the patient encompasses the time  from the completion of the surgical procedure to the com-  plete return of the patient to the normal physiological  state. This is divided into three phases. Phase I is early  recovery and takes place in the postanesthesia care unit  (PACU). Phase II is intermediate recovery, and takes place  in the ward. Phase II is late recovery that occurs after  discharge.    Postoperative care of the patient begins immediately after  the surgical procedure has been completed, even before the  anesthesia is reversed. The first step is clearing the airway of  blood and debris. Maxillomandibular fixation and occlusal  splints, if placed earlier need to removed [1]. The next step is  the removal of the throat pack.   The decision to extubate or not must be made in conjunction  with the anesthetist. Cases in which there is a high risk of  airway edema will require the ET tube to be retained [1].  These include:   Oral and Maxillofacial Surgery, Sri Ramachandra Institute of  Higher Education and Research, Chennai, India    P. Ravi  Department of Oral and Maxillofacial Surgery, SRM Dental  College, Ramapuram, Chennai, Tamil Nadu, India    © The Association of Oral and Maxillofacial Surgeons of India 2021   ¢ Severe facial trauma where there is likelihood of blood  ooze, edema, or tongue fall back.    In other cases, the patient may be extubated on the table.  Awake extubation is usually preferred for head and neck sur-  gery. The patient may be extubated when the following crite-  ria are met [1]:   ¢ Patient is able to sustain head lift for at least 5 seconds.   ¢ Patient is breathing on his own, with respiratory rate less  than 24/min, tidal volume greater than 5 ml/kg, and  Spo2 > 90%.    Once the extubation is done, an oropharyngeal airway can  be inserted to prevent clenching of teeth and the tongue from  falling back, which can cause obstruction. Alternatively, a  nasopharyngeal airway can be used in case the surgeon  deems oral cavity unfit for manipulation using the former.  This must remain in place until the patient is conscious and  obeys commands.   Some patients, such as those who have undergone exten-  sive face and neck resection, may have required a tracheos-  tomy prior to surgery. The tube must be secured after surgery  by taping the stay sutures to the neck or chest. Tracheostomy  care in the postoperative period is critical; a blocked or dis-  lodged tube can have disastrous consequences [2].    2. The tube stoma must be covered with a humidifying bib,  or a moist gauze.    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1-15-1346-6_12    3. The tube must be suctioned regularly to prevent clogging  due to secretions. The suction catheter must be inserted to  half of its length, which will correspond to the carina  (Patients usually cough when this point is reached).  Suction is then applied while simultaneously withdraw-  ing the catheter.   4. To break up secretions, small quantities of sterile water  can be syringed in and suctioned immediately.    12.1.1.2 Need for Ventilation in the PACU  In some instances, ventilation may be required even after  anesthetic recovery. Some examples include:    1. Patients who have history of COPD.  2. Severe trauma or infection.    While monitoring the patient who is on a ventilator, it is  important to be aware of the various modes that the ventila-  tor operates on [3]. These have been summarized in  Table 12.1. Patients who have been on the ventilator for long  periods of time need to be weaned off slowly. OMF surgeons  frequently come across such patients in neurosurgical ward  having concomitant traumatic brain injuries and craniomax-  illofacial fractures. This may be done by setting the ventila-  tor in CPAP mode (Continuous Positive Airway Pressure).  This allows the patient to breathe, with the ventilator taking  over if the patient is unable to do so.    Once the patient has been shifted to the recovery room, the  cardiac monitor and pulse oximeter must be attached for    Ventilator  mode Type of setting Description/indications  Volume Continuous Patients with respiratory muscle  control mandatory weakness or LV dysfunction  ventilation (CMV) _ If patient breathes rapidly, may  cause hyperinflation and  Synchronous ; :  : ‘ respiratory alkalosis  intermittent  mandatory Patient breathes partially on their  ventilation (SIMV) own; meant for patients who  breathe rapidly on CMV  Mandatory breaths are  synchronized with spontaneous  breathing  Pressure Pressure controlled Patients with neuromuscular  control ventilation (PCV) disease but normal lungs who can    ventilation Used during weaning, patient  determines respiratory volume and  frequency, but the ventilator  provided continuous positive    ¢ Oxygen Saturation: Hypoxia can occur in the postopera-  tive period and the patient must be kept on oxygen for  1-2 h (2-6 L/min) to prevent this. Oxygen may be deliv-  ered using a face mask or through nasal prongs.   ¢ Pulse, blood pressure: Increase in these parameters may  indicate pain. Serious complications (Infarction,  Malignant hyperthermia) may produce a drastic change in  these parameters and must be recognized.   ¢ Postanesthesia tremors/shivering: This can occur on the  table during recovery from anesthesia. It can occur if the  patient is hypothermic, and is commonly associated with  the use of halogenated anesthetics. Management consists  of rewarming the patient. Tramadol and meperidine may  be used to stop uncontrollable shivering [4].    The suction apparatus must be kept handy to evacuate blood  ooze or secretions that may hamper the airway. It is advisable to  avoid Maxillomandibular fixation (MMF) in the immediate  postoperative period; if required, this may be done after 24 h.   Detailed surgical notes must also be recorded, along with  the number and type of implants that were used. Postoperative  instructions must also be documented in detail. A list of  notes to be completed by the surgeon before leaving the  operation theater complex is summarized in Table 12.2.    12.1.1.4 Briefing the Patient and Family  Immediately after the surgery, the surgeon must interact with  the patient’s immediate caregivers, giving them the details of  the procedure, and any anticipated complications.   This is done when the patient has regained consciousness,  with adequate respiratory function and stable vitals.  Decisions can be made based on a standard scoring system,  such as the Aldrete scoring system [5]. The scoring system  which was originally proposed in 1970, underwent modifi-  cations in 1995 and 1999. The various factors considered   Postoperative instructions to be followed by nursing staff  Postoperative fluid management instructions  Postoperative medication dose and schedule    Whether the pain medication is adequate or  whether it needs to be increased or  discontinued (see Sect. 12.2.2.1)    Nausea/vomiting If the patient has experienced this, assess the  need for antiemetics, and insertion of  nasogastric tube to decompress the stomach.  (Secty 12255)   It is important to evaluate branches of the  facial nerve and trigeminal nerve that may  have been at risk of damage during surgery  Inability to pass urine may indicate  inadequate fluid therapy, and may lead to  acute renal failure. (see Sect. 12.2.5.6)  Inability to pass stools may be a sign of  paralytic ileus; may occur after iliac crest  harvest    are patient activity, respiration, circulation, consciousness,  O, saturation, pain, surgical site bleeding, and nausea/vom-  iting. Patients scoring greater than 9 on this scale can be  moved to the ward for the next phase of care. Readers are  advised to refer the article for getting a detailed idea of the  scoring table.    This is done according to the SOAP format [6]. SOAP is an  acronym for Subjective, Objective, Assessment, and Plan. In  Subjective evaluation, the patient must be asked if they have  any complaints. Specific complaints are recorded. In  Objective evaluation, a thorough evaluation of the patient is  done by the physician. This includes evaluation of the vital  signs, fluid intake and output, as well as an assessment of the  surgical site. Helpful information may be obtained from the  TPR chart, input/output chart, and nurses’ notes. Based on  the subjective and objective evaluation, the patient’s current  status is assessed (Tables 12.3 and 12.4). This is used to for-  mulate a plan.   Sometimes investigations may be required in the postopera-  tive period, either to check the health status of the patient or  to confirm the diagnosis of certain complications. A list of  investigations that may be ordered and the indications for the  same are summarized in Table 12.5.   Changes in pulse and blood pressure have  several causes (Sect. 12.2.5.3)   If abnormal, evaluate whether the patient has  respiratory distress (Sect. 12.2.5.4)    Fluid input/output  Is the input adequate? (Sect. 12.2.1)  Is urinary output adequate? This helps assess  renal function(Sect. 12.2.5.6)   Surgical site evaluation  The wound must be inspected, and assessed  for healing. (Sect. 12.3)   If there has been extensive blood loss during  surgery, to determine the need for blood  transfusion.    The patient is usually ‘nil per mouth’ for a few hours prior to  surgery and after surgery. Apart from this, there is a loss of  blood and body fluids in any surgery, which requires replace-  ment. It is therefore essential to infuse intravenous fluids  during this period [7, 8]. This is done for two purposes.    Replacement Any fluid deficit that has occurred must be  replaced by infusion. This could have occurred during either  of the following periods:    ¢ Preoperative period: This could be due to  — NPO status.  — Blood or fluid losses that may have occurred due to  trauma, burns, etc.  ¢ Intraoperative period: Surgical blood loss of greater than  500 ml or 7 ml/kg requires replacement.    Maintenance This is to maintain the ongoing fluid require-  ments, till the patient resumes oral intake of fluids.  Maintenance fluids are essential to maintain proper pH and  electrolyte balance and for adequate organ perfusion.   There are three types of fluids than can be used—crystal-  loids, colloids, blood and blood products. The preference of  one type of fluid over another has several controversies, and  there are no clear-cut guidelines available [9]. A few indica-  tions for each fluid type are given below.   Crystalloids are balanced salt solutions with or without the  addition of a buffering agent. When infused into the blood-  stream, crystalloids tend to leave the capillaries and enter the  extravascular fluid compartment. Crystalloid infusion will  increase fluid in the extravascular tissues and does little to  expand the circulating blood volume. In maxillofacial sur-  gery, crystalloids are favored as maintenance fluids during  the postoperative period.   Colloids are protein-containing solutions. Since these pro-  teins have a large molecular size, under ordinary circum-  stances, these are prevented from crossing the capillary  endothelial cells and going into the extravascular space.  Therefore, they tend to expand vascular volume alone.  Colloids are mostly used in the intraoperative period if there  has been significant blood loss and the plasma volume needs  to be expanded. It is not common to use colloids in the post-  operative setting.    1. The input-output chart must be verified before determin-  ing the fluid requirement. This will help to estimate fluid  excess (positive balance), or deficits (negative balance)  and plan requirements.   This is done using Holliday and Segar’s formula (The  4-2-1 rule) [10].   E.g. a 60 kg adult will require (4 x 10) + (2 x 10) + (1 x  40) = 40 + 20 + 40 = 100 ml/h.   3. Calculate the total Estimated Fluid Deficit: This depends  on the number of hours from the last oral intake to the  next oral intake. For example, if the patient has not had  oral intake for 12 h:   EFD = EFR x no. of NPO hours = 100 x 12 = 1200 ml.   4. Estimate the surgical blood loss. If crystalloids are used  to replace this blood loss, for a particular volume of  blood, three times the volume of crystalloids are used for  replacement. If colloids are used, the same volume is  sufficient.   5. Estimate the amount of fluids that have already been  infused during anesthesia.   EFD+(blood loss x 3)—fluids replaced during surgery.  In the above scenario, if 300 ml of blood was lost, and one  liter of fluid was infused during surgery, then:   In recent years, the above method of estimating fluid require-  ments has been criticized, as it tends to overestimate the  amount of fluids needed by a patient [11]. Excessive fluid  infusion may cause fluid shift into the extravascular compart-  ment, which in turn can result in overload complications such  as renal injury, acute respiratory distress syndrome, etc. On  the other hand, liberal fluid infusion can reduce postoperative  complications such as nausea, vomiting, and drowsiness.   For major systemic surgeries, the current trend is either to  follow a ‘restrictive’ approach or a goal-directed therapy.  Goal-directed therapy measures hemodynamic parameters  such as stroke volume, and fluids are given accordingly.  While this has been found useful in major surgeries,  particularly abdominal surgeries, there is no evidence on its  effectiveness in postoperative recovery for maxillofacial sur-  gery. A liberal approach may be preferred for most kinds of    Epstein-Barr virus, B-19 parovirus, dengue,  chikungunya, HHV-8, malarial parasite)  Transfusion reactions    Postoperative  hemoglobin Risk factors/compensatory Transfusion  level mechanisms present requirement  <6 g/dl Required  6-8 g/dl No risk factors Not required  Presence of risk factors (coronary Required  artery disease, heart failure,  cerebrovascular disease/limited  mechanisms of compensation)  Presence of symptoms indicative of Required  hypoxia (physiological transfusion  triggers: Tachycardia, hypotension,  electrocardiographic signs of  ischemia, lactic acidosis, etc.)  8-10 g/dl Presence of symptoms indicative of Required  hypoxia (physiological transfusion  triggers: Tachycardia, hypotension,  electrocardiographic signs of  ischemia, lactic acidosis, etc.)  Absence of above symptoms Not required  >10 g/dl Not required    maxillofacial surgery, which generally fall under low or  intermediate risk procedures. Nevertheless, as long as post-  operative fluids are being administered, the patient must be  monitored for signs of overhydration such as peripheral  edema, dyspnea, high blood pressure, and a bounding pulse.  If any of these are present, the current fluid regimen must be  reassessed [12].   Products  Postoperative blood transfusion is rarely required in routine  maxillofacial surgery. It has been stated that the risks of  blood transfusion outweigh the benefits [13] (See Table 12.7),  and currently a restrictive approach to blood transfusion is  favored.   If there has been extensive blood loss during surgery, or  preexisting anemia, the postoperative hemoglobin must be  assessed, and the decision to transfuse is based on this level  [14]. This is described in Table 12.8.    The maxillofacial surgeon must be aware of the type and  dosage of medication that is required in the immediate post-    operative period. Pain control and prophylaxis against infec-  tion are the most important factors to be kept in mind while  prescribing medication.   Pain control is an important goal after every surgical proce-  dure as it can not only affect the patients’ attitude, but it can  also impair oxygenation and thereby delay wound healing.  The pain must be assessed subjectively, by asking the patient  to rate their pain on a standard scale (e.g. Visual Analogue  scale or Faces pain scale). If the patient is in pain, pain medi-  cation must be increased or changed.   Preemptive analgesia is an evolving, controversial tech-  nique that involves the administration of analgesics prior to  the onset of noxious stimuli. This is believed to limit the sen-  sitization of the nervous system, thereby reducing the need  for postoperative analgesia [15]. One effective preemptive  technique is the infiltration of a long-acting local anesthetic,  such as bupivacaine, into the incision site before closure.  This provides effective pain relief throughout the postopera-  tive period.   In the postoperative period, various classes of analgesics  may be used [16]. Some of the commonly used analgesics  are summarized in Table 12.9.   The best method of choosing the appropriate analgesic is  using the WHO analgesic ladder (Fig. 12.1). If the pain is not  well controlled, the patient can move to the next step of the  ladder. Once the pain is controlled, patients must be weaned  by moving down the ladder [17]. This step ladder approach  is just a broad lattice and has its own share of controversies  and modifications. Readers are encouraged to read appropri-  ate references for getting a broader picture of the analgesic  ladder and a detailed discussion is beyond the scope of this  chapter.    Patient-controlled Analgesia Postoperative patients often  require immediate pain relief at varied intervals. PCA allows  the use of iv pumps which, when the patient presses a button,  allows a bolus dose of analgesic to be delivered for immedi-  ate relief [18]. This allows analgesics to be tailored to the  patients’ requirements and also records the amount of opioid  being administered per day.   The role of corticosteroids in postoperative care is controver-  sial. Corticosteroids are potent anti-inflammatory agents and  are often used after surgery. It has been established that cor-  ticosteroids reduce pain and inflammation [19]. There is also  evidence that single doses of steroids can reduce postopera-  tive nausea and vomiting, and improve fatigue after surgery.  However, the benefit of extended doses of steroids seems  controversial and comes with the risk of impaired wound  healing, infectious complications, and hyperglycemia. It is    Drug Classification frequency adverse effects  Diclofenac NSAIDS (aryl 75 mg bd Has been linked to  acetic acid adults adverse  derivatives) 1.5 mg/kg cardiovascular  bd children events—Avoid in  patients with heart  disease  Gastric ulceration  and bleeding may  worsen  Nephrotoxic; avoid  in patients prone to  kidney disease  Aceclofenac 100 mg bd Less than  adults diclofenac, mild GI  Safety not symptoms have  established been reported  in children  Ketorolac NSAIDS 20-30 mg GlIsymptoms,  qohr hypertension  0.5 mg/kg reported in few  qohr patients  Acetaminophen NSAIDS 0.5-1 gtds Hepatotoxicity  (paracetamol) (Para-amino adults  phenol 10-15 mg/  derivative) kg children  Tramadol Synthetic 50 mg bd or May worsen nausea  opioid sos and vomiting. Like  Safety not all opioids,  established respiratory  inchildren. depression is higher.  Morphine Natural opioid 0.2—0.8 mg/ Respiratory  kg bd depression, nausea,  vomiting,    therefore recommended that steroids be used only till the  first postoperative day. Dexamethasone 8 mg is generally  used twice a day. For single day dosing, taper is not generally  required.   Enzymatic anti-inflammatory medication is also used to  reduce postoperative edema [20]. These include serratiopep-  tidase (10 mg tds) or trypsin:chymotrypsin (chymoral,  100,000 IU). However, its efficacy is based mostly on anec-  dotal reports and there is hardly any scientific evidence to  back its use.   The use of antibiotic prophylaxis (for wound infections)  in maxillofacial surgery is a controversial area. Literature  evidence is insufficient to ascertain whether prophylaxis  is required or not, and the duration of prophylaxis has no  definite guidelines. Based on recent systematic reviews,  Table 12.10 sums up current recommendations [21, 22].   Amoxicillin 500 mg per oral tds (OR) Cefotaxime | g IV  bd with Metronidazole 500 mg IV tds.   Prophylaxis must be started 30-90 min before the surgical  procedure. The postoperative regimen has no clear guide-  lines, but must continue for at least 24 h after the procedure.  After this, the wound must be monitored for infection, and  therapeutic antibiotics may be instituted only if required. This  section is covered in more detail in Chap. 10, of this book   Preoperative and intraoperative fasting, as well as drugs used in  the postoperative period, can induce gastric irritation in the sur-  gical patient. To counter this, drugs that reduce the acidity of  gastric secretions may be used. Ranitidine, a H2 blocker, may  be used in a dose of 50 mg bd. An alternative drug is Pantoprazole,  which may be used in a dose of 40 mg once a day.   Prevention of postoperative nausea and vomiting is an  important factor in postoperative care. One of the important  drugs used for the management of PONV is Ondansetron,  which is given in a dose of 4 mg [23]. This is usually a rescue  medication and is not given on a routine basis.   Patients undergoing prolonged surgery or hospitalization  may be at increased risk of developing thromboembolic  events, namely deep vein thrombosis and pulmonary embo-  lism. Additional risk factors include smoking, pregnancy,  oral contraceptives, and malignancy. These patients must be  placed on thromboprophylactic drugs. In indicated cases,  TED (thromboembolic deterrent) stockings have to be used  in the postoperative patients. The guidelines are summarized  in Table 12.11 [24].   Based on the Patients’ Medical History  If the patient has other medical comorbidities, medication  that was being taken prior to the procedure may need to be  continued or modified. It is best to confer with the patients’  physician to determine the dosage and kind of drugs needed.  These have been summarized in Table 12.12.    Maxillofacial surgical procedures provide a unique chal-  lenge to the nutritional status in the postoperative period.  Pain and edema in the oral region often prevent the patient    from taking food comfortably, and there is a tendency to eat  less or not at all. In patients with intermaxillary fixation,  there is an inability to open the mouth and chew food. In  certain kinds of surgery, such as reconstructive flaps involv-  ing the oral region, the patient is asked to avoid taking food  by mouth at all to prevent the possibility of infection and flap  failure in the postoperative period.   It is important, however, that the nutritional status is  maintained. Inadequate nutrition has been shown to increase  morbidity and mortality and can delay wound healing. It also  increases the patient’s susceptibility to infection. In the  young, healthy adult patient, nutritional support may not be  required, as the body compensates for decreased intake by  increased glycogenolysis, gluconeogenesis, lipolysis, and  amino acid oxidation. However, in young children, patients   Wi *Codeine, Tramadol or Low dose.  fe) Ss Morphine  S *Morphine, fentanyl, oxycodone,  opioids hydromorphone    Moderate Low molecular weight heparin,  <3400 units per day  OR intermittent pneumatic    High Low molecular weight heparin,  >3400 units per day  OR intermittent pneumatic    Highest Low molecular weight heparin,  >3400 units per day AND  intermittent pneumatic    Table 12.12 Additional drugs that may be required in the postopera-   Patient on Low molecular weight heparin for 24 h, after  anticoagulants which warfarin should be resumed    with preexisting malnutrition, and patients with wasting dis-  eases, supplementation may be required for even routine pro-  cedures. Patients who do not have adequate oral intake for  7-14 days (3-10 days in children) will require support to  avoid malnutrition [25].   Nutritional status must be evaluated in the postoperative  patient. This usually calls for consultation by a dietician. For  long-term patients, nutritional status can also be measured  using certain tools. The accepted tool for assessment is the  subjective global assessment scale [26].   In patients on intermaxillary fixation, the classic use of  the nasogastric tube must be discouraged. Patients may be  educated on taking food through the retromolar region, using  a feeding tube. NG tubes may be reserved for cases in whom  oral feeds are contraindicated to avoid infection. Nutritionally  complete formulas (e.g. Ensure) are available for enteral  feeds. The patient may be started on 50 ml formula every 4 h,  and this may be gradually increased in 50 ml increments  until the desired target is achieved. After each feed, the tube  must be flushed with 30 ml water to prevent blockage.   In cases of extensive neck surgery, where swallowing may  be impaired, percutaneous gastrostomy (PEG) or jejunos-  tomy tubes may be placed. For these tubes, infusion feeds (at  the rate of 20 ml/h, increased in 20 ml increments every 4 h)  may be given.   Total parenteral nutrition is usually not preferred because  it has been linked to higher rates of infectious complications  as compared to enteral nutrition. Patients who have complete  block of the gastrointestinal system or those who cannot tol-  erate or retain enteral feeds are candidates for TPN. Dextrose  solutions are preferred, with a dose of 10-20 g/kg/day of glu-  cose. This is used in conjunction with amino acid solutions  (0.5—3.5 g/kg/day) and lipid emulsions (50 ml/hr) [25].    After the surgical procedure, early mobilization is recom-  mended for all patients. Early mobilization is believed to  enhance recovery by reducing the incidence of postoperative    complications. It reduces secretions in the lungs, accelerates  peristalsis, and improves venous blood flow to the extremi-  ties, thereby preventing thrombophlebitis and deep vein  thrombosis [27]. Immobilization increases the risk of com-  plications such as DVT and pressure sores. It can also lead to  urinary retention.   For most maxillofacial procedures, the patient may be  allowed to sit up with legs dangling 6 h after surgery. The  patient may be mobilized within 24 h, and it is recommended  that they ambulate every 4-6 h (during waking hours) till dis-  charge. Caution must be employed in patients who have had  grafts or flaps taken from the fibula. While the early mobili-  zation protocol must be followed, protected weight bearing  may be employed.   For patients who require prolonged bed rest, the use of  alternating pressure mattresses or gel mattress overlays must  be considered to prevent pressure sores.   Chest physiotherapy forms an important component of  postoperative care. The in-hospital patient is prone to  increased lung secretions and infections, which may be  cleared using chest physiotherapy.   Maxillofacial surgery and surgery to the neck carry a risk of  edema and hematoma developing in the postoperative period  that can compress on the airway. The airway must be moni-  tored closely, both in the immediate postoperative period and  during the stay in the ward.   If the patient presents with hypoxia and airway obstruction,  the head tilt-chin lift-jaw thrust maneuver must be employed.  The airway must be checked manually and cleared of obstruc-  tion such as vomitus or blood. If the airway obstruction is at or  above the oropharynx, insert an airway (such as Guedel’s) to  keep the passage patent. If there is a hematoma compressing  the airway, surgical sutures must be removed to allow a release  of pressure. In extreme cases, emergency airway procedures  such as cricothyroidotomy may need to be performed.   Fever is defined as a rise in body temperature above 38 °C  (100.4 °F). Postoperative fever represents a diagnostic chal-  lenge for most surgeons. Although most cases of fever are  self-limiting, some can be serious and need urgent interven-  tion. The timing of postoperative fever often gives a clue as  to its diagnosis and management [28, 29].   Fever in the immediate postoperative period is most likely to  be an inflammatory response to surgery. The surgical proce-    dure causes release of pyrogenic cytokines, which stimulate  the anterior hypothalamus to release prostaglandins, causing  a rise in body temperature. The extent of fever depends on  the amount of tissue trauma, but usually resolves in 24 h.  Laboratory and diagnostic workup is not warranted for this  kind of fever.   Occasionally, immediate fever can occur due to more seri-  ous reasons, and it is important to identify these. Malignant  hyperthermia is a rare, life-threatening disorder that can man-  ifest in susceptible individuals when they are exposed to inha-  lational anesthetics, or succinylcholine. There is an immediate  rise in body temperature during or up to | h after surgery. It  may be recognized by an immediate rise in ETCO,, tachy-  pnea, tachycardia, and muscle rigidity. Prompt intervention is  required to avoid muscle lysis and organ system failure.  Treatment involves immediate intravenous Dantrolene  sodium (2.5 mg/kg), repeated every 5 min till reversal occurs,  or till the maximum dose is reached (10 mg/kg).   If the fever occurs during or immediately after a blood  transfusion, it is a sign of transfusion reaction. Transfusion  of incompatible (mismatched) blood can cause a severe  hemolytic reaction, which, in addition to fever, can present  with dyspnea, fever, and myoglobinuria. In such cases, the  transfusion must be discontinued immediately. Sometimes,  febrile reactions can also occur with compatible blood, due  to reaction of recipient antibodies with antigens in the trans-  fused blood. This fever will be accompanied by headache,  nausea, and vomiting. Slowing the transfusion may suffice,  but it must be stopped if the reactions become severe.   Adverse drug reactions can rarely cause fever. This is usu-  ally a diagnosis of exclusion, and if suspected, all drugs must  be discontinued one at a time to identify the offender. If  replacement is necessary, a chemically unrelated drug must  be used.   A serious cause of postoperative fever in this time period is  deep vein thromboembolism. This must be suspected if the  patient has known risk factors, such as a history of smoking,  malignant disease, prolonged surgery, advanced age, or pro-  longed immobility after surgery. Diagnosis is made by ultra-  sound or impedence plethysmography. If present, prompt  systemic anticoagulation must be started to avoid fatal pul-  monary embolism. The use of Homan’s sign (Pain in the calf  on forced dorsiflexion of the foot) is no longer recommended  because of the risk of dislodging the thrombus into circula-  tion. A suspected PE may be confirmed with a ventilation-  perfusion (V/Q) scan of the lungs.   Thrombophlebitis can also cause a rise in body tempera-  ture. Any iv line in place for more than 24 h can cause phle-  bitis. This presents with pain, erythema, and edema at the  affected site. The iv line must be removed and replaced, and  anti-inflammatory drugs may be given. A topical ointment  containing heparin and benzyl nicotinate (thrombophob)  may be applied locally.    Atelectasis was once thought to be a cause of fever, but it  is now believed that fever and atelectasis are unrelated,  though they can coexist. Aspiration pneumonia is more  likely to be a respiratory cause of fever, but it presents  3-5 days after surgery.   Surgical site wound infections can result in fever 3-5 days  after surgery. The surgical site must be examined for pain,  swelling, and pus discharge if fever occurs during this period.  If an infection is present, it must be managed as detailed in  the following sections.   Aspiration pneumonia can occur if the gastric fluid is  aspirated into the lungs, owing to a depressed cough reflex  after surgery. The risk increases in patients on maxilloman-  dibular fixation.   Fever beyond the fifth postoperative day is usually a sign of  systemic infection and needs a diagnostic workup. The most  common infections that can occur are urinary tract infection  and upper respiratory tract infection.   Indwelling urinary catheters are the main source of UTIs.  Women are at greater risk because they have a shorter ure-  thra; however, both genders can develop UTI if the catheter  is in place for more than 72 h. Concomitant signs such as  burning sensation on passing urine may be present. Urine  will appear cloudy. Diagnosis is best confirmed by urine cul-  ture; empirical antibiotics may be started in the meantime.   Respiratory tract infections can range from sinusitis to hos-  pital-acquired pneumonia. In Hospital Acquired Pneumonia  (HAP), chest auscultation may reveal crackles or rales, and  diagnosis is made by chest x-rays. Treatment is by empirical  antibiotics.   A rare infection that can occur beyond the fifth day is nec-  rotizing soft tissue infection. Although this is more common  after colorectal surgery, cervical necrotizing infection has  been reported after maxillofacial surgery as well [30].  Diagnosis may be made by detecting subcutaneous ‘gas’ on  x-rays or CT imaging. Treatment involves the use of broad  spectrum antibiotics and fluid resuscitation.   With all systemic infections, blood culture must be done  to rule out sepsis. It is also important to monitor the patient’s  vitals closely to ensure that the patient does not go into septic  shock.    It may be of interest to know that in the literature there  is a mnemonic of 6 W’s, with regard to causes of post-  operative fever. The W’s being Waves (ECG changes,  MI), Wind (atelectasis, pneumonia), Water (UTI),  Wound (surgical site infection), Walking (Venous  thromboembolism), Wonder drugs(drug-related fever).    <24 HOURS  INFLAMMATORY walmmignies  RESPONSE TO HYPERTHERMIA  SURGERY  TRANSFUSION ADVERSE DRUG  REACTIONS REACTIONS  24-28 HOURS 48 HOURS TO 5 DAYS BEYOND 5 DAYS  SYSTEMIC  DVT WOUND INFECTION dncraone  ASPIRATION  THROMBOPHLEBITIS ASE eae    12.2.5.3. Changes in Pulse and Blood Pressure  Any gross deviation from the normal vital signs must be  looked into. Changes in pulse (tachycardia or bradycardia)  are usually associated with changes in the other vital signs as  well, and these must therefore be evaluated first.  Hypotension in the postoperative period can occur due to  several causes [6] (Fig. 12.3). Hypotension is usually the  result of reduced plasma volume; this may be due to inade-  quate fluid resuscitation, or ongoing blood loss. Excessive  usage of opioid analgesics may also cause a fall in blood  pressure. A myocardial infarction and blood sepsis may also  present with hypotension. Hypotension with tachycardia can  be a sign of developing shock; which must be treated imme-  diately with a fluid challenge (rapid bolus of fluid).  Regardless of the cause, hypotension must be managed by    increasing fluid input and supplemented by high-flow oxy-  gen to improve the perfusion.   Raised blood pressure usually occurs in patients who  have had preexisting hypertension. If the patient has a his-  tory of ischemic heart disease or cerebrovascular disease, it  must be managed with appropriate medication, to reduce the  risk of developing myocardial infarction or stroke postopera-  tively. Sometimes, hypertension may occur in healthy adults  with no history. In these cases, it could reflect pain and anxi-  ety, or distension of the bowel and/or bladder. Excessive  fluid resuscitation may also result in hypertension [6].    12.2.5.4 Changes in Respiration  Increase in respiratory rate (tachypnea) is usually a sign of  respiratory distress, and may be accompanied by decreased    oxygen saturation, and use of accessory muscles of respira-  tion [6]. Sudden acute shortness of breath may be a sign of  pulmonary embolism. Gradual onset that occurs within  2-5 days of surgery is commonly due to atelectasis.  Atelectasis is the collapse of a small segment of the lung and  commonly occurs after general anesthesia. Atelectasis after  maxillofacial surgery may be obstructive in nature, occurring  secondary to epistaxis or mucus secretion. Another reason  for the slow onset of respiratory distress is Acute Respiratory  Distress Syndrome (ARDS), which can occur secondary to  hypovolemia, sepsis, or trauma. Respiratory infection and  cardiac causes such as myocardial infarction or cardiac fail-  ure can also alter respiratory rate. The various causes are  illustrated in Fig. 12.4.   If a person experiences shortness of breath, high-flow  oxygen must be started, and a chest x-ray and EKG must be  taken. Laboratory tests including cardiac enzymes and arte-  rial blood gases must be performed to ascertain the cause. If  sputum is present, it must be sent for culture and gram  staining.   This is acommon complication that occurs due to activation of  the nucleus tractus solitarius and vomiting center by inhala-  tional anesthetics. Patients who undergo maxillofacial surgery,  particularly orthognathic surgical procedures, are at increased  risk of developing postoperative nausea and vomiting, due to  accumulation of blood in the throat. It can affect 20-80% of all  patients, the risk being higher in young patients, females in the  first 8 days of their menstrual cycle, and obese patients [23].  This complication is best managed symptomatically using  antiemetics such as ondansetron and metoclopramide.   The normal urine output is 1 ml/kg/h in infants, 0.5 ml/kg/h  in children, and at least 400 ml/day in adults. Any drop below  this level is referred to as oliguria and this must be addressed  to prevent acute kidney injury (AKI). AKI is diagnosed as  oliguria, along with serum creatinine levels 1.5 times above  baseline [6]. The various causes of postoperative oliguria  and management are outlined in Table 12.13.    Type of  oliguria/  AKI Cause Management  Prerenal Hypovolemia Fluid challenge of 250 ml  iv fluid over 1 h  Hypotension Address the cause of  hypotension  Renal Nephrotoxic drugs: Discontinue the offending  NSAIDS, drug  aminoglycosides, steroids Aggressive treatment with  Sepsis broad spectrum antibiotics    Care of the surgical wound site begins even before closure of  the wound has been completed. It may be necessary to place    A drain is a device that is intended to evacuate fluids and air  from the surgical wound site. By evacuating accumulated  pus, blood, and serous fluid, they help prevent infection of  the surgical site. By evacuating air, they help eliminate dead    CHEST X-RAY, WBC, ACUTE  EOE CARDIAC SPUTUM ANALYSIS EXACERBATION OF  CAUSES THE DISEASE  (CONFIRM  (MI, CARDIAC  WITH V/Q  ane FAILURE) |  ) (CONFIRM  WITH ECG)  ATELECTASIS  PNEMONIA  ARDS    The various kinds of drains are summarized in Table 12.14.  Drains may be classified as:    ¢ Active drains: These work under negative pressure and  actively remove fluids and air from the surgical site.   e Passive drains: They drain fluids passively, and are  dependent on gravity. Passive drains may be open or  closed.    ¢ The drain must be inserted before the last layer of sutures  is placed.   ¢ The drain tube has a needle at one end and perforations at  the other end.   ¢ The needle is inserted from the deeper edge of the surgi-  cal wound, and pulled out through the skin surface, about  2 cm away from the wound margin. The end with the per-  forations must remain within the surgical site.   ¢ The exit of the needle must be in a dependent area, lower  than the incision line.   ¢ The needle is cut off from the tube and discarded safely.   ¢ The drain tube is secured with sutures to the skin  surface.   ¢ The bulb or container is deflated completely, to ensure  negative pressure, and is then attached to the exit end of  the tube.   ¢ Dressing with betadine gauze is done around and over the  drain tube.    Example Indications for use Image  Jackson-Pratt drain _ Inserted into the surgical site to drain _ stopper aN  blood and serous fluid; to eliminate > aN    Surgical Site Catheters  Catheters may be inserted directly into the surgical site beneath  the skin sutures. These may serve the following purposes:    e Analgesia: An intravenous cannula inserted into the surgi-  cal site may be used for delivering local analgesia. Long-  acting anesthetics, such as ropivacaine and bupivacaine,  are delivered through this into the surgical site. This is  especially useful in the iliac crest after harvest of autoge-  nous bone.   ¢ Local antibiotic therapy: Infected spaces or osteomyelitic  bone may benefit from local antibiotics that are delivered  via catheters.   e Marsupialization: Decompression of a cystic lesion may  be followed by catheter insertion into the cystic cavity.  This allows continued drainage of fluid from the cyst.   Once complete suturing of the wound has been completed,  appropriate dressing of the wound site must be carried out.  Various types of dressing material are available [31]. These  are detailed in the Chap. 11 on soft tissue injuries and  management.    e Aim to leave the wound undisturbed for at least 48 h after  surgery.   e Premature removal of the wound dressing may, however,  be required in certain situations. These include:   e Suspicion that the wound site is infected (e.g. Postoperative  fever with no other attributable cause).   ¢ The dressing is no longer serving its purpose (e.g. Falling  off).   e Ifthe wound dressing is being changed, check if there is  excess exudate or devitalized tissue that may delay wound  healing. If these are present, the wound must be cleansed.  This is done by gentle irrigation of saline (for the first  48 h) or clean tap water (after 48 h) using a syringe. The  wound must never be swabbed with gauze, as this can  delay healing.    e The drain must be monitored every 4 h and more fre-  quently if the discharge from the wound is excessive.   e The drain container must be evacuated at least once every  day.   ¢ Once the drain fluid collection goes below 25-50 ml/day,  the drain may be removed.    Surgical site catheters must be removed by the third postop-  erative day.    Postoperative Bleeding, Hematoma, and Seroma  Bleeding after surgery is classified as primary (occurs during  or immediately after the surgical procedure), reactionary  (occurs after few hours, possibly due to slipped ligatures),  and secondary (occurs after few days, commonly due to  infection). Active, ongoing bleeding is referred to as  hemorrhage.   Hematoma refers to a clotted collection of blood below  the tissues, which occurs due to damage to vessel walls.  Most hematomas are self-limiting. Larger hematomas can be  treated with ice packs or compression dressings. Analgesics  may be given if the swelling is painful. Hematomas in the  submandibular and neck region, or other regions which can  potentially compress the airway, must be drained surgically.   Seromas are collections of serous fluid that generally  develop 5-7 days after surgery. They are more common in  extensive surgeries, particularly in neck dissection, where  lymph nodes have been removed. Small seromas resolve  over time. If the seroma is large and painful, the fluid may be  aspirated and a pressure dressing can be applied.   As maxillofacial procedures are clean-contaminated surger-  ies, they carry a higher risk of developing infection as com-  pared to clean surgeries. Signs and symptoms of an infected  wound include:    If the wound appears infected, a few sutures must be  removed and pus must be drained out. A swab must be sent  for culture and sensitivity testing, and the patient must be  started on empirical antibiotics. The patient must be moni-  tored closely for signs of systemic infection. The infected  wound can be treated by local debridement and antibiotic  irrigation.   This generally occurs as a result of one of the above compli-  cations, most commonly subacute infection. Sometimes,  however, it may simply be the result of excessive wound ten-  sion due to inadequate tissue undermining. If the wound is  uninfected less than 24 h postoperatively, re-suturing may be  attempted. Otherwise, the wound is best left to heal by sec-    ondary intention. Resistant wound dehiscence may lead to  orocutaneous communications and may become difficult to  handle. The decision to either allow these to granulate or sur-  gically provide a cover depends on individual scenarios.    While the general rules apply to all kinds of surgeries, there  may be extra measures which are required in each specific  surgery type. These are outlined below [2].   e Inthe immediate postoperative period, the airway must be  monitored. This may get compromised due to bleeding or  edema.   ¢ For fractures of the zygoma and orbit, monitoring for ret-  robulbar hemorrhage is important. This can be diagnosed  by the three Ps—pain (in the orbit), proptosis, and pupil-  lary defects [33]. The postoperative care team is generally  required to check papillary reflexes on an hourly basis for  the first 6 h which can be relaxed to once in 2 h for the  next 6 h. Any impending sign of diminishing vision or  pupillary inactivity is brought to the notice of the consul-  tant and steps initiated accordingly.   e Assess and document paresthesia along any nerves  involved in the fractured segment. This includes the infe-  rior alveolar nerve for mandibular fractures and infraor-  bital nerve for zygomaticomaxillary complex fractures.   e The accuracy of reduced fractures must be checked on the  first postoperative day using radiographs. For fractures  involving the dentoalveolar segments, occlusion may be  used as a guide.   e As with trauma patients, airway compromise due to  bleeding and edema must be monitored.   ¢ Considerable facial swelling is common. Ice packs and  systemic steroids can help reduce swelling.   ¢ Occlusion must be checked on the first postoperative day,  and elastics must be placed if required. Class II elastics  are placed from the upper anterior teeth to lower posterior  teeth. Class III elastics are placed from lower anteriors to  upper posterior teeth.   e These patients usually undergo extensive surgery that  lasts for hours, and will therefore need intensive monitor-  ing in the postoperative period. Tracheostomy care may  be required (See Sect. 12.1.1).    ¢ Most of these patients will be unable to feed properly till  wound healing is complete. Ryle’s tube or PEG insertion  must be done on the day of surgery or the first postopera-  tive day.   ¢ Patients must be on DVT prophylaxis. The malignancy,  prolonged surgery, and in-hospital stay increase the risk  of the patient developing DVT.    ¢ Reconstructed flaps must be monitored for vitality. If  the blood supply to the flap is lost due to thrombi, it  may be salvageable within the first 48 h. Periodic mon-  itoring ensures prompt surgical intervention if the need  arises.   e Flaps may be monitored using a handheld Doppler.  Capillary refill may be assessed for flaps which are not  buried. The needle prick test is simple, but must be done  only to confirm congestion or loss of vitality.   ¢ Flaps must be monitored hourly for the first 24 h, and 4  hourly for the next 48 h.    Table 12.15 lists the complications that may be encountered  with each specific surgery.    Prolonged hospital stay increases the patient’s risk of devel-  oping nosocomial infections. Therefore, the patients must be  discharged as soon as feasible. Criteria for discharge are as  follows:   ¢ Patient can take nutrition independently or with the aid of  a caregiver.    Discharge summary: This is a record given to the patient,  detailing the diagnosis, procedure performed, and any  implants that were used. Instructions and medications to be  taken must also be noted.   Follow-up appointments must be made for review. In case  facial and neck incisions were placed, an appointment for  suture removal must be given.   Trauma Malunion/nonunion Reopen, remove cause  of malunion, induce  bleeding, use of graft    Orthognathic Condylar Re-surgery, removal of  surgery malpositioning leading __ plates, repositioning the  to anterior open bite condyle and re-fixation  (BSSO)  Inferior alveolar nerve _ Palliative management  paresthesia  Alar base widening Alar cinching    Postoperative care requires a thorough understanding of the  patient, the procedure they have undergone, and the expected  outcome. Surgeons must realize that more often it may be the  first experience for a patient in going under the knife and  lying at the ICU or ward. Hence, a perfect coherence of sci-  entific and psychological views is required of the surgical  team at all levels. The chapter emphasizes the need for  comprehensive management of the maxillofacial patient at  the ward after their procedure. The reader is expected to  understand that outcome depends, but not ends at operating  room or ward/ICU.    . Cascarini L, Schilling C, Gurney B, Brennan P. Oxford handbook    of oral and maxillofacial surgery. Oxford: Oxford University Press;  2018 August 2.    . Aldrete JA. The post anaesthesia recovery score revisited [letter]. J    of surgery. 26th ed. Boca Raton, FL: CRC Press; 2013 Feb 18.    and blood product usage. Oral Maxillofac Surg Clin North Am.  2006;18:7-17.    . Kayilioglu SI, Dine T, Sozen I, Bostanoglu A, Cete M, Coskun   Chesney RW. The maintenance need for water in parenteral fluid  therapy, by Malcolm A. Holliday, MD, and William E. Segar,  MD, Pediatrics, 1957; 19: 823-832. Pediatrics. 1998 Jul  1;102(Supplement 1):229-30.   Doherty M, Buggy D. Intraoperative fluids: how much is too much?  Br J Anaesth. 2012;109(1):69-79.   Della Rocca G, Vetrugno L, Tripi G, Deana C, Barbariol F, Pompei  L. Liberal or restricted fluid administration: are we ready for a pro-  posal of a restricted intraoperative approach? BMC Anesthesiol.  2014;14(1):62.   Chao J. Transfuse or not to transfuse: for postop anemia. Am J Clin  Med. 2011;8(1):11-4.   Liumbruno GL, Bennardello F, Lattanzio A, Piccoli P, Rosetti  G. Recommendations for the transfusion management of patients  in the peri-operative period. III. The post-operative period. Blood  Transfus. 2011;9:320-35.   Ong CK, Lirk P, Seymour RA, Jenkins BJ. The efficacy of preemp-  tive analgesia for acute postoperative pain management: a meta-  analysis. Anesth Analg. 2005 Mar 1;100(3):757-73.   Coulthard P, Haywood D, Tai M, Jackson-Leech D, Pleuvry  B, Macfarlane T. Treatment of postoperative pain in oral and  maxillofacial surgery. Br J Oral Maxillofac Surg. 2000;38(6):  588-92.   Vargas-Schaffer G. Is the WHO analgesic ladder still valid?  Twenty-four years of experience. Can Fam Physician. 2010 Jun  1;56(6):5 14-7.    . Fleischli J, Adams W. Use of postoperative steroids to reduce pain    Kreutzer K, Storck K, Weitz J. Current evidence regarding pro-  phylactic antibiotics in head and neck and maxillofacial surgery.  Biomed Res Int. 2014;2014:1-7.   Dobbeleir M, De Coster J, Coucke W, Politis C. Postoperative nau-  sea and vomiting after oral and maxillofacial surgery: a prospective  study. Int J Oral Maxillofac Surg. 2018;47(6):721-5.   Lachiewicz PF. Comparison of ACCP and AAOS. guidelines  for VTE prophylaxis after total hip and total knee arthroplasty.  Orthopedics (Online). 2009 Dec 1;32(12):74.   Fang J, Chirag D, Dym H. Nutritional aspects of care. Oral  Maxillofac Surg Clin North Am. 2006;18(1): 115-30.   da Silva FJ, Daniel de Mello P, Daniel de Mello E. Subjective  global assessment of nutritional status — a systematic review of the  literature. Clin Nutr. 2015;34(5):785-92.   Dolgun E, Giersbergen M, Aslan A, Altinbas Y. The investigation of  mobilization times of patients after surgery. Asian Pac J Health Sci.  2017;4(1):71-S.    Ansari R. Fever work-up and management in postsurgical oral and  maxillofacial surgery patients. Oral Maxillofac Surg Clin North  Am. 2006;18(1):73-9.   Jadwani S, Bansod S, Chug A, Misra B. Management of postopera-  tive fever in oral and maxillofacial surgery patients. Asian J Oral  Maxillofac Surg. 2010;22(1):2-6.   Tung-Yiu W, Jehn-Shyun H, Ching-Hung C, Hung-An C. Cervical  necrotizing fasciitis of odontogenic origin: a report of 11 cases. J  Oral Maxillofac Surg. 2000;58(12):1347-52.   Ovington LG. Advances in wound dressings. Clin Dermatol. 2007  Jan 1;25(1):33-8.   Yao K, Bae L, Yew WP. Postoperative wound management. Aust  Fam Physician. 2013;42(12):867—70.   Bater MC, Ramchandani PL, Brennan PA. Post-traumatic eye  observations. Br J Oral Maxillofac Surg. 2005 Oct 1;43(5):410-6.    Open Access _ This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.  org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropri-  ate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.    The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in    a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.   Exodontia is the removal of tooth from its socket in the  alveolar bone with the help of anesthesia. It is a challeng-  ing procedure in itself as the dental surgeon has to work in  an oral cavity, access to which is restricted by patient’s lips  and cheeks. Also, the movement of the tongue and the jaw  makes the procedure troublesome. Another factor which  complicates the procedure is saliva. The oral cavity commu-  nicates with the pharynx which further communicates into  larynx and esophagus, due to which there is always a poten-  tial risk of aspiration or deglutition of the extracted tooth.  Hence, it is of paramount importance that the exodontia must  be performed judiciously and be based on sound surgical  principles.   Apart from the competence and practical skills of the  dental surgeon, patient’s cooperation also holds the key to  an uneventful extraction of a tooth. Patient’s cooperation is  dependent on various factors like misinformation, myths,  anxiety, pain phobia, patient’s previous exodontia experi-  ences, and trust over the operator. A dental surgeon must have  a calm, patient, and reassuring approach towards the patient  to gain his/her confidence. This empathetic nature of the doc-  tor must be superadded with good principles of patient man-  agement and pharmacokinetics. This combination helps in  controlling patient’s anxiety and fear toward the procedure.    Exodontia or tooth extraction is defined as the painless  removal of a whole tooth or tooth root, with minimal trauma  to the investing tissues, so that the bone heals uneventfully  and no postoperative prosthetic problem is created [1].   Oral and Maxillofacial Surgeon, Department of Trauma and  Emergency Medicine, All India Institute of Medical Sciences,  Bhopal, Madhya Pradesh, India    © The Association of Oral and Maxillofacial Surgeons of India 2021    The thought of how extractions were performed in eleventh  century is disturbing. The operator used to hold the patient’s  head between his knees, the soft tissue was cut with a sharp  scalpel, and the tooth was pulled out in single direction.  Often the wound was cauterized with a red hot iron and a  repellent mouthwash was prescribed [2].   Historically, dental extractions were carried out as a pro-  phylactic as well as therapeutic treatment for a variety of ill-  nesses. Before the discovery of antibiotics, exodontia was a  preferred treatment. Dentistry was not a separate profession  at that time and mainly the barbers were extracting the tooth  popularly known as ‘barber surgeons’. They used to hang  rows of rotten teeth outside their shops to advertise their ser-  vices as tooth pullers [3].   Various kinds of instruments were used in different geo-  graphical areas of the globe and can be grouped as forceps,  pelicans, keys, screws, and elevators. The modern-day for-  ceps have been evolved over time and are highlighted in  Table 13.1.   Regarding Indian history, Sushruta is to be credited for  his description of surgical instruments. He highlighted two  types of instruments viz. ‘Yantra or blunt’ and ‘Shastra or  sharp’. And among the category yantra, “dantasanka’ — a spe-  cial forceps for extraction of teeth is described [6]. Vagbhata,  around 650 AD, described forceps for extraction of tooth [7].   The jaw bones namely maxilla and mandible harbor the  teeth in their respective alveolar process within the shape-  appropriate sockets designed by nature. Sharpey’s fibers of  periodontal ligament attach the teeth to their alveolar sockets  with the joint called gomphosis.    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1-15-1346-6_13    It can be assumed that extractions were carried out considering the prominent carvings of forceps on the walls of  Egyptian caves in the work of Edwin Smith Papyrus [4].  Hippocrates referred that the dental forceps have been discovered in Greece. These forceps were made up of Iron    Guy de Chauliac invented pelicans for dental extraction. They were named after the bird from their resemblance to    the shape of the beak. The early drawing of the pelican showed a straight shaft, a wheel-shaped bolster, and a single    claw attached to the shaft by a rivet [2].  4 Sixteenth century    Dental key (also known as clef de Garengeot, fothergill key), an instrument modeled after a door was popular. It was    first inserted horizontally into the mouth, then its claw would be tightened over the tooth to be extracted. Once  secured, rotation movements were carried out to loosen the tooth. It was continuously modified for better results;  however, its use was often associated with complications [2].    13.4.1. Maxilla (Fig. 13.1)  It is a paired bone forming the midface of a person, bearing  upper teeth separating the oral cavity from the nasal cavity  and maxillary sinuses. Compared to the mandible, it is com-  posed of spongier bone with thinner cortical plates. Palatal  processes extend from both the maxillary bone and meet in  the midline to form the roof of the oral cavity. The branches  of Maxillary Nerve innervate the maxillary teeth and their  periodontium (Table 13.2).    1. The maxilla is characterized by thin cortical plates with  spongier bone due to which the alveolar sockets expand eas-  ily on the application of pressure, facilitating extraction.   2. Due to thin cortical plates, mere para periosteal infiltra-  tions of local anesthetic solutions produce adequate anes-  thesia to perform a dental extraction. However, in cases  where adequate anesthesia is not achieved, a nerve block  is desirable.   3. Maxilla has better vascularity as compared to mandible  due to which the healing is faster with minimum  complications.    1. Use of heavy elevators is associated with the risk of fracture  of the alveolar bone. Hence, their use must be judicious.   2. The root apices of maxillary molars are in close proxim-  ity to the floor of maxillary sinus with a thin bone separat-  ing them. Due to which there are chances of.   (b) Spread of periapical infection into the sinus leading  to odontogenic maxillary sinusitis.    (c) Displacement of the root into maxillary sinus if inju-  dicious retrieval is attempted in the event of a root  fracture.   3. The maxillary third molar is present in the maxillary  tuberosity as it is the last tooth to erupt. There are high  chances of maxillary tuberosity fracture in patients with  unfavorable and bizarre root patterns especially in the  elderly as the tuberosity is made up of spongy bone.    It is horseshoe shaped, mobile and the heaviest bone of  the craniofacial skeleton. Compared to maxilla, it has less  spongy bone as well as vascularity and has thick cortices.  The branches of Mandibular Nerve innervate the mandibular  teeth and their periodontium (Table 13.3).    NPN: Palatal soft tissue  Lateral incisor and canine  NPN: Palatal soft tissue    Premolars MSAN: Tooth and its buccal soft tissue  GPN: Palatal soft tissue  First molar MSAN: Mesiobuccal root    PSAN: Tooth and its buccal soft tissue  GPN: Palatal soft tissue  PSAN: Tooth and its buccal soft tissue  GPN: Palatal soft tissue  Abbreviations: ASAN Anterior Superior Alveolar Nerve, VPN Nasopalatine Nerve, MSAN Middle Superior Alveolar Nerve, GPN Greater Palatine  Nerve, PSAN Posterior Superior Alveolar Nerve    Teeth Nerve supply Nerve blocks  Incisors and Inferior alveolar nerve: Inferior alveolar  canine Teeth nerve block  Mental nerve: Buccal soft Mental nerve block  tissue Lingual nerve block   Long Buccal nerve:  Buccal soft tissue  Lingual nerve: Lingual  soft tissue   Local infiltration on buccal aspect  Posterior superior alveolar nerve block  Greater palatine nerve block    1. Presence of thick cortical plates makes it a requirement to  apply more pressure for luxation and extraction of teeth  as the sockets do not expand readily.   2. Due to less vascularity, healing is slower as compared to  maxilla.   3. Mandible is depressed when the mouth is open. Hence,  there are high chances of temporomandibular joint  injury or dislocations if the mandible is unsupported  with the application of forces in a long-standing  procedure.    Apart from the bone, the anatomy of teeth also plays a piv-  otal role in an uneventful extraction. The shape of crown and  roots must be assessed carefully, preoperatively. A narrow  tapering crown requires the use of a lighter beaked forceps  whereas a bulbous crown needs to be extracted using heavy  beaked forceps. If the tooth is multirooted, it offers more  resistance than a single-rooted tooth and cannot be extracted  using a rotational force, as such a motion will lead to root  fracture. In cases where the roots are divergent, the applica-  tion of heavy forces will lead to root fracture. Dilacerated  roots are also prone to fracture on the application of injudi-  cious forces. Also, a more careful approach is required while  extracting non-vital and endodontically treated teeth, as they  fracture readily due to their fragile and brittle nature second-  ary carious undermining and loss of pulpal tissue.    Extraction of the teeth can be either prophylactic or therapeutic.  Following are the indications for exodontia (Box 13.1).   (a) Malposed teeth: The teeth which are misaligned and  cannot be reoriented within the proper arch form  with orthodontic treatment.   Severe Periodontal Disease  Periapical Pathology  Orthodontic Reasons  Preprosthetic Extractions  Fractured Teeth    (b) Creation of Space: To gain space to align malposed  teeth. In such cases, premolars are commonly  extracted.   (c) Serial Extractions: During the mixed dentition  stage, a few deciduous teeth are extracted in a  sequential manner to avoid malocclusion in perma-  nent dentition as the child grows.    cation of a complete denture or extraction of a few unde-  sirable teeth to provide better design and stability to a  removable partial denture.    ous problems like recurrent ulcerations under a denture,  initiation of bony pathologies, and numbness if in close  proximity to nerve. However, considerably small asymp-  tomatic root fragments may be left alone but the patient  needs to be kept under regular follow-up (Fig. 13.3f).    impacted. They predispose to malocclusion, pain, peri-  odontal disturbance, pathologies, or sometimes esthet-  ics. If there is no advantage in retaining a supernumerary  tooth, it must be subjected to extraction (Fig. 13.3g).  Retained Decidous Teeth: Deciduous teeth which are  retained beyond the age of exfoliation.   Impacted Teeth: Teeth impacted in the jaw and creating  discomfort to the patient or identified incidentally and  found to be initiating some pathological changes within  the bone (Fig. 13.3h).   Tooth in fracture line (Fig. 13.31): The extraction of  tooth in fracture line has always been controversial. In  earlier times, all the teeth in fracture line were extracted  but in recent times a more conservative approach is  advocated. The teeth in fracture line are indicated for  extraction if the tooth is a source of infection at the site  of the fracture, the tooth itself is fractured, or the reten-  tion of the tooth in fracture line may interfere with the  fracture reduction or healing.   Teeth associated with pathologies (Fig. 13.3j): Teeth  involved in cyst formation and associated with other  pathologies like tumors, osteomyelitis, or neoplasms.  Teeth in firing line of radiations: In the past, prophylac-  tic extractions were carried out before the patient was  subjected to radiation therapy. This practice was done as  the effects of radiation, such as loss of vascularity of  bone and radiation caries of the tooth, leading to a risk of  osteoradionecrosis. However, with betterment in tech-  nology, it is not commonly practiced anymore.    Fig. 13.3 (a) Intraoral periapical radiograph showing grossly carious  second molar indicated for extraction. (b) Clinical Photograph showing  pulpal pathology. (c) Clinical Photograph showing generalized peri-  odontitis. (d) Radiograph showing developing root caries following  endodontic treatment. (e) Radiograph showing fractured central inci-    sors. (f) Clinical Photograph showing root pieces. (g) Clinical  Photograph showing supernumerary teeth. (h) OPG showing impacted  mandibular canine. (i) OPG showing left mandibular third molar in  fracture line. (j) OPG showing cyst associated with impacted maxillary  canine    A tooth may be indicated for extraction, but the presence of  certain factors makes it contraindicated for extraction at that  particular time. Any medical disorder in an uncontrolled,  severe, or acute state may become a relative contraindication  for extraction. However, once the underlying medical condi-  tion is controlled, the patient may be fit to undergo extrac-  tion. These relative contraindications may be classified as  systemic or local contraindications.   2. Pulmonary disorders like bronchial asthma, tuberculosis,  chronic obstructive pulmonary disease, and pulmonary  effusion.   3. Cardiovascular disorders like hypertension, cardiomy-  opathy, valvular disorders, ischemic heart disease, and  chronic cardiac failure.    6. Metabolic disorders like diabetes mellitus, thyrotoxico-  sis, Addison’s disease, myxedema, and long-term steroid  therapy.   7. Hematologic disorders like severe anemia, leukopenia,  thrombocytopenia, pancytopenia, leukemia, agranulocy-  tosis, patients on anticoagulant drugs, and bleeding and  clotting disorders.    1. Tooth in a malignant growth: Cases where a tooth is asso-  ciated with a malignant tumor is generally mobile due to  the destruction of periodontal tissues because of the  underlying disease process and patients often insist for  extraction. Extraction of such tooth must be considered as  a relative contraindication because extraction may cause  seeding of malignant cells into the capillaries subse-  quently leading to distant metastasis of the tumor [6].   2. Tooth associated with vascular lesions: There is a high  risk of catastrophic bleeding while extracting the tooth  associated with vascular lesions like hemangiomas, aneu-  rysms, arteriovenous malformations, etc. Hence, such  extractions should be carried out while treating the  pathology in a controlled environment.   3. Tooth in close proximity to vital structures: The extraction  should be avoided to prevent injury to vital structures.   4. Tooth in an irradiated jaw: An irradiated jaw is highly  avascular; carrying out the extraction of a tooth in such  condition is associated with a high risk of osteoradione-  crosis. However, such a tooth can be extracted after a con-  siderable period of time following radiation therapy [8].   5. Tooth with an acute infection: If a tooth associated with acute  infective pathology is extracted, there is a risk of extension of  infection into deeper tissue planes due to loss of natural bar-  riers during surgery. Also, there are chances of ingress of  microorganisms into blood stream resulting in bacteremia.  This may cause pyrexia and bacterial endocarditis in suscep-  tible patients. Hence, in such a situation, the tooth must be  extracted under proper antibiotic coverage. Apart from anti-  biotics, local measures for the drainage or decompression of  the infective pathology should be carried out if possible. This  relieves the pain and discomfort of the patient [9].   Forceps are the basic instruments used to perform exodontia.  They are based on principles of simple machines. Forceps  are designed to provide adequate access to the targeted tooth  without injuring the neighboring tissues. Forceps basically  have three components: (Fig. 13.4).    e The handle: Handle is the area of forceps from where the  operator holds the instrument in a palm grip. It has serrations  to facilitate firm grip. It is longer as compared to the beaks,    corresponding to the longer arm of the lever, providing max-  imum mechanical advantage.   e The Hinge: It the area where the beaks and handle unite  with each other and this part corresponds to the fulcrum  of the lever.   ¢ The beaks: Beaks are shorter as compared to the handle  and correspond to the short arm of the lever, providing  maximum mechanical advantage. The beaks of maxillary  forceps are parallel to the handle, whereas the beaks of  mandibular forceps are at a right angle. This helps in the  application of beaks parallel to the long axis of the tooth.  The beaks are curved and designed specifically for differ-  ent teeth for proper two-point contact. The outer surface  of beaks are smooth and tapering, facilitating wedging  between the tooth and alveolar process. However, the  inner surface of beaks are serrated to provide a firm grip  over the tooth.    1. English Pattern: These forceps have a hinge that is  directed vertically to the handles of the forceps.   2. American Pattern: These forceps have a hinge that is directed  in a horizontal direction with the handles of the forceps.    Tables 13.4 and 13.5 describe various maxillary and man-  dibular forceps with their salient features, respectively.   Maxillary forceps must be held in a ‘palm up’ position  (Fig. 13.7a) and mandibular forceps must be held in a ‘palm  down’ position (Fig. 13.7b). These forceps majorly apply  five different motions: (Fig. 13.8).    1. Apical pressure: With the force in this direction, the  tooth movement is minimal in apical direction; however,  the socket expands due to insertion of beaks in the peri-  odontal ligament space. Also, the center of rotation of  tooth displaces apically, resulting in less amount of force  at the apical portion of root preventing it from getting  fractured. (Fig. 13.9).   2. Buccal/Labial pressure: This results in expansion of buccal  cortical plate, specifically at the crest of the ridge. However,  at the same time, it results in lingual apical pressure.  However, excessive pressure must be avoided to prevent  fracture of buccal bone and the apical portion of the root.   3. Palatal/Lingual pressure: Similar to the buccal/labial  pressure, but in opposite direction aiming in the expan-  sion of lingual cortical plate.   4. Rotational pressure: Here the tooth is rotated resulting in  internal socket expansion and tearing of periodontal liga-  ments. This force must only be applied to the teeth with  single and conical roots. Teeth with multiple or dilacerated  roots are prone to fracture on the application of this force.    bifurcation of roots and blunt on the other side engaging  palatal root. Handle is similar to that of premolar forceps.    4 Maxillary cow horn forceps _ These are also paired forceps having beaks that resemble the — Extraction of maxillary molars with  (Fig. d) horns of the cow, pointed on one side engaging buccal extensive loss of coronal structure.  bifurcation and notched on the other engaging palatal root.  5 Maxillary third molar forceps Beaks are curved and angulated to engage the crown of third —__ Extraction of maxillary third molars  (Fig. ) molars. Handle is long for accessing the posterior region.  6 Maxillary bayonet forceps Beaks of the forceps are narrow, symmetrical, and Extraction of maxillary roots.  (Fig. ) approximating. Handle is angulated to provide access to    Fig. 13.5 (a) Maxillary anterior forceps, (b) Maxillary premolar forceps, (c) Maxillary molar forceps, (d) Maxillary cow horn forceps, (e)  Maxillary third molar forceps, (f) Maxillary bayonet forceps   5) Mandibular third molars These are paired forceps having an angulated beak to reach up Extraction of mandibular third molars  (Fig. €) to the mandibular third molars. Both beaks have triangular   molar forceps (Fig. 13.6f) that they are facing forward toward each other at right angles    Fig. 13.6 (a) Mandibular anterior forceps, (b) Mandibular premolar forceps, (¢c) Mandibular molar forceps, (d) Mandibular cow horn forceps, (e)  Mandibular third molar forceps, (f) Mandibular molar forceps (American pattern)    Fig. 13.7 (a) Correct way of holding maxillary forceps, (b) Correct  way of holding mandibular forceps  ©Association of Oral and Maxillofacial Surgeons of India    5. Tractional forces: This delivers the tooth out of the socket. Elevators are the instruments used for luxating (loosening)  This force should be gentle and the tooth should not be the teeth before application of forceps making extraction  pulled out of the socket. However, if excessive force is easier, subsequently avoiding complications like fracture  required, other maneuvers must be carried out to improve of crowns, roots, and bone. They are also used to remove  luxation. fractured or surgically sectioned roots. Elevators are single-    Fig. 13.9 Center of rotation of  tooth gets displaced apically  when the forceps is inserted  beyond cementoenamel junction    ing maximum mechanical advantage with minimum efforts. * Blade: It is the working end of the instrument and trans-    Elevators have three components (Fig. 13.10): mits the force to the tooth, bone, or both to achieve the  ¢ Handle: It is of generous size for proper grip and deliv- desired action.   continuation of the shank or at a right angle to the shank. Table 13.6 highlights various types of elevators used for    e Shank: It connects the handle with the working end or exodontia and Fig. 13.12 shows the proper way to hold an  blade of the elevator. It is strong enough to transmit the — elevator.  force from the handle to the blade.   shank at a right angle to  handle. The blade is  triangular with slight  curve and pointed tip.   There are three maxillary third  @©Association of Oral and Maxillofacial Surgeons of India elevators, two angled molars, and teeth    Fig. 13.11 (a) Straight elevator, (b) Coupland elevator, (c) Apexo elevator, (d) Cross bar elevator, (e) Cryer elevator, (f) Warwick James elevator,  (g) Root tip elevator    between the bone and tooth parallel to the long axis of the  tooth is wedging. A wedge is basically a movable inclined  plane which overcomes a larger resistance at right angle  to the applied effort. The resistance has its effect on the  slant side when the effort is applied at the base of the  plane (Fig. 13.13a and b).    . Lever Principle: The elevator is the lever of first class. To    gain mechanical advantage in first-class lever, the effort  arm must be longer (3/4th of the total length) than the  resistance arm divided by the fulcrum which lies on the  bone (Fig. 13.14a and b).    . Wheel and Axle Principle: In this principle, the effort is    applied to the circumference of a wheel, which turns the  axle generating the force to raise a weight (Fig. 13.15).    The procedure of exodontia is a blend of surgical principles  and elementary physics mechanics. When this combination  is applied efficiently, a tooth can be removed with no great  difficulty and finesse without requiring a large amount of  force. For an uneventful extraction to be carried out, a proper  sequential procedure must be followed.    e Presurgical Medical Risk Assessment:  The approach of a dental surgeon must not be localized  to a diseased tooth. It should always be kept in mind that  we are not treating a tooth but we are treating an indi-  vidual with a diseased tooth. It is critical that the sur-  geon must examine the patients’ medical status. Patients  may suffer from a variety of medical ailments requiring  modification in treatment planning. Medical manage-  ment must be carried out first for safe extraction proce-  dure for the patient.   ¢ Emotional Condition of the patient:  Due to various myths like weakening of eyesight and  impact on mental health following extraction as well  as severe intolerable pain during the procedure, the  patients are generally apprehensive to undergo extrac-  tion. Such patients are liable to go into syncope or  aggravation of their medical condition. A proper coun-  seling is required in such cases before proceeding for  exodontia. However, in extremely anxious patients,  where counseling is not enough, premedication like  Diazepam/Alprazolam (Anxiolytics) for reduction of  anxiety may be considered.   e Extraoral Examination:  The patient must be examined for the presence of any  extraoral swelling, cellulitis, abscess, or lymphadenopa-  thy. Presence of any swelling is suggestive of extension  of infection into surrounding soft tissue space which may  require another surgical procedure. Presence of trismus  must also be examined as it affects the access to the tooth  to be extracted.   ¢ Intraoral Examination:  It includes an examination of the size of the tongue, bulky  buccal fat pad, and hyperactive gag reflex as these fac-    Fig. 13.13 (a) Wedge principle a  where a wedge is used to expand,  split, and displace portions of the  substance that receives it, (b) The  blade of the elevator is used as a  wedge to displace the tooth root  out of the socket    Fig. 13.14 (a) The small force and large movement transformed to small movement and large force by the first-class lever, (b) The tooth is ele-  vated out of the socket where the bone acts as a fulcrum    Fig. 13.15 The elevator  acting on the principle of  Wheel and Axle aids in  retrieval of root from the  socket    tors may hamper the access to the surgical site. Acute  signs of infection like inflammation, edema, and pus  discharge must also be assessed and the procedure must  be performed under local antiseptic care and antibiotic  coverage.  ¢ Examination of the tooth in question.   These factors play a significant role in the extraction  procedure. The status of the adjacent tooth should also be  examined as in its absence the interdental bone cannot be  used as a fulcrum. Moreover, if it is carious, there are    radiograph provides accurate and sufficient details of the  tooth, its root/s, and the surrounding tissue.   Examination of the following factors must be done:  — Configuration of roots  — Size of roots  — Shape of roots  — Number of roots  — Root form  — Presence of dilacerations  — Resorption  — Hypercementosis   A proper radiograph also gives an idea regarding the  proximity of the root to the vital structures such as infe-  rior alveolar neurovascular bundle and maxillary sinus.  Moreover, the condition of surrounding bone can also be  identified for the presence of sclerotic bone or periapical  pathologies like cyst, abscess, or granuloma.    chances of fracture of the adjacent tooth while application  of elevator in the interdental space.  Radiographic Examination.   It is advisable to take a proper radiograph for any tooth  which is to be extracted. Generally, an intraoral periapical    As the proverb says ‘Failing to plan is planning to fail’, it  is of paramount importance to device a proper treatment  plan before carrying out an extraction procedure. The degree    of difficulty must be anticipated during the pre-extraction  period. On assessment, if it is believed that the degree of  extraction is high or the initial attempts of extraction confirm  it, a deliberate surgical approach must be planned. A large  amount of force during simple exodontia must be avoided as  it may injure local soft tissue and damage surrounding bone  and teeth. There are also chances of crown fracture which  makes the procedure more difficult. Also, the application of  excessive force aggravates the intraoperative and postopera-  tive discomfort of the patient.    Extraction of the tooth can be effectively carried out under  local anesthesia. Hence, administration of local anesthesia  must be carried out with proper technique and appropriate  agent. For different teeth, different nerve blocks are to be given  (Tables 13.2 and 13.3). Once the local anesthesia, nerve block  and/or local infiltration is administered, surgeon must wait for  it to act and confirm the same by subjective and objective tests.    The principle of universal precaution states that all the  patients must be viewed as having blood-borne diseases that  can be transmitted to the surgical team and other patients.  Hence, to avoid transmission of diseases, a surgeon and the  assistant must wear surgical gloves, surgical mask, eye-wear  with shields, surgical cap, and a long-sleeved surgical gown.  Before the patient is subjected to the extraction procedure, a  sterile drape should be put over the patient’s chest to decrease  the risk of contamination. It is advisable to reduce the bac-  terial contamination in the patient’s mouth by making him/  her rinse the mouth vigorously using an antiseptic rinse like  chlorhexidine prior to the procedure. Some surgeons prefer  to keep a partially unfolded 4 x 4 inches’ gauze loosely into  the back of the mouth to prevent the tooth or its fragment  from potential aspiration or swallowing. However, it should  not be kept posterior enough to trigger gag reflex.    The positions of the operator, the patient, and the chair are  very important for comfortable and successful extraction.  The best position is one that is comfortable for both the  patient and surgeon and which allows the surgeon to have  maximum control during the procedure.    e Chair and Patient’s Position (Table 13.7).  ¢ Operator’s Position (Table 13.8) (Figs. 13.16 and 13.17).    Choosing the correct technique and following fundamental  principles, leading to an atraumatic extraction. The three  fundamental requirements for a good extraction are:    (a) Adequate access and visualization of the surgical field.  (b) An unimpeded pathway for the removal of the tooth, and  (c) Use of controlled force to luxate and remove the tooth.    Dental extractions are based on three mechanical proper-  ties, which are as follows:    1. Expansion of alveolar socket: The tooth itself is used as a  dilating instrument to expand the alveolar socket in order  to permit the removal of its harbored tooth. This is per-  formed mainly in ‘intra-alveolar exodontia’ by holding  the tooth firmly with a forceps and carrying out lateral  movements in buccal and lingual directions (Fig. 13.18).  This expansion depends on the elasticity of the bone  which is maximal in young bone and decreases with age.  Dilatation of socket results in microfractures in the bony    wall and interradicular septa. The bony fragments retain  the periosteal attachment in almost all the cases and hence  must be digitally compressed unless an implant placement  is planned.   . Use of Lever and Fulcrum: This principle is used to lux-  ate the tooth or root and force it out of the socket along  the path of least resistance. This principle is the basic fac-  tor which governs the use of elevators to extract tooth or  tooth root (Fig. 13.14b).   . Insertion of a wedge of wedges: Insertion of wedge  between the tooth/root and bony socket wall leads to the  rise of tooth in the socket (Fig. ). Lesser the elastic-  ity of bone, more are the effects of wedging. This is the  reason that sometimes on application of blades of for-  ceps, the conical rooted mandibular premolars shoot out  of the sockets.    Fig. 13.16 Operator’s position for maxillary teeth extraction, (a) Right posterior, (b) Anterior, and (c) Left posterior    3.17 Operator’s position for mandibular teeth extraction, (a) Right posterior, (b) Anterior, and (c) Left posterior    referred to as closed method or routine exodontia, usually  practiced for extraction of erupted and intact tooth with  enough structure to grasp with a forceps and pull the tooth  out of alveolar socket. Instruments used are forceps or ele-  vators or both. This technique is the most frequently used  technique for almost every extraction. However, if the  operator believes that the extraction will require an exces-  sive force or if a substantial amount of crown is missing or  covered by tissue, an open technique may be opted.   5 sequential steps are to be followed for exodontia by  closed technique (Fig. 13.20). Other than these 5 steps,  the opposite hand also plays a vital role during the proce-  dure which is highlighted in Table    Fig. 13.18 (a) Exodontia by a  expansion of bony socket is  similar to the removal of a post  embedded in the ground, (b) The  post is moved laterally in a to and  fro motion, (c) This results in  displacement of soil surrounding  the post and permitting the post  to be removed out    2. Transalveolar Exodontia: This method includes removal  of alveolar bone to access and extract the tooth. It is gen-  erally practiced for extraction of impacted teeth, root  pieces, or teeth with unfavorable root form. It is often  termed as surgical extraction or complicated exodontia.  Indications for open technique are enlisted in Box 13.2.  For an open technique exodontia, 5 steps are to be fol-  lowed: (Fig. 13.23) (Clinical Case, Fig. 13.24a-f).    Transalveolar exodontia necessitates incision making and  subsequent mucoperiosteal flap reflection for adequate expo-  sure of the underlying alveolar bone. The flap must be an  adequate sized full-thickness mucoperiosteal flap with a  broader base which is made on intact bone, avoiding injury  to the local vital structures. The various types of flaps used in  transalveolar exodontia are:    1. Envelope Flap: When a crevicular incision without any  releasing incision is given, it produces an envelope flap.  Usually, this flap provides adequate access to perform the  surgery (Fig. 13.25a).   2. Triangular Flap: When a crevicular incision has one verti-  cal releasing incision, it produces a triangular flap. It is also  known as a two-sided or three-cornered flap. The three cor-  ners are posterior end of the crevicular incision, inferior    Soft tissue attachment is loosened from the cervical portion of tooth  Can be effectively done using scalpel blade, moon’s probe or sharp end of No. 9 Molt’s  Periosteal elevator  This step helps in  a. Ensuring if anesthesia has been achieved  b. Gaining patient's confidence that only pressure will be felt  Cc. More apical positioning of blades of forceps and elevators   It is then rotated slowly and forcefully so that the inferior portion of blade rests on the bone and  its superior porion pushes the tooth   In some cases, opposite movement results in complete removal of tooth    Tooth is grasped apical to cervical line with appropriate forceps  Lingual beak is applied first followed by buccal beak  Application of beaks must be parallel to the long axis of the tooth    ¢ Pinch grasp: While extracting  maxillary teeth, the operator grasps  the alveolar bone around the tooth   Protection of other teeth to be extracted by a pinch grasp    aspect of vertical releasing incision, and the superior aspect  of the vertical releasing incision. When a greater exposure  is required, this flap is preferred (Fig. b).    This results in effective dilation and expansion of the alveolar bone on application of apical  Forceps must be grasped at ends to maximize the control and mechanical advantage    ¢ As described earlier, various motions are carried out to luxate the tooth  Once the tooth is luxated, apical force is applied again to shift the centre of rotation further    This is again followed by buccal and lingual movements of tooth.  The forces applied in buccal and lingual direction must be slow deliberate pressures with no    ¢ Once the force is applied, one must wait so that the bone expands  e A slight traction force directed slightly buccally is applied over the tooth.  ¢ The tooth comes out of the socket once the socket is completely expanded and periodontal    ¢ Once the tooth is out, the tooth and socket both must be examined for any fractured root tips.    trapezoidal flap. It is also known as a three-sided or four-  cornered flap. Two corners are at the superior aspect of  the releasing incisions and the other two corners are at the  ends of the crevicular incision. The vertical releasing  incisions are not vertically placed but are directed  obliquely to allow a broader base (Fig. c).    It starts by incision making and reflecting a sufficiently  large flap to provide adequate visualization and access.  Mostly an envelope flap is preferred which is extended at  least two teeth anterior and one tooth posterior to the tooth  that has to be extracted. If required, a releasing incision can  be placed. Once the flap is reflected adequately and the  surgical site is exposed sufficiently, extraction of the tooth/  root must be performed by using one of the various options.    Fig. 13.22 Sling grasp for mandibular teeth (a) Right posterior, (b) Anterior    First option is to reseat the extraction forceps under  direct visualization achieving a better mechanical  advantage and removing the tooth without removing  any bone.   Second option is to grasp a bit of buccal bone along  with the root in order to obtain a better mechanical  advantage. In this case, a small amount of buccal  bone is pinched off and removed along with the tooth    Third option is to push the tooth out of the socket by  inserting a straight elevator into the periodontal liga-  ment space of the tooth. A small to and fro movement  should be used to insert the straight elevator as a  wedge by expanding the periodontal ligament space  to displace the root in an occlusal direction  (Fig. D).   Fourth option is to remove the bone covering the buc-  cal aspect of root with the help of a bur along with  ample irrigation. The width of the bone to be  removed must be essentially equal to the mesiodis-  tal width of the root. Also, the amount of bone to be  removed in the vertical dimension should be  approximately one half or two thirds the length of  the root (Fig. 6c). Removal of this much amount  of bone minimizes the force necessary for the dis-  placement of the root, making the procedure easier.  The extraction can be carried out using forceps or  elevator.   In some cases, removal of the root is still difficult  even after the removal of bone. In such cases, a pur-  chase point can be made in the most apical position  of the exposed root with the help of a round bur. This  purchase point must be 3 mm in diameter and deep    ¢ Based on basic principles of flap designing, an incision is placed and a full thickness mucoperiosteal flap is    e The bone is removed from buccal aspect using chisel or burs.  e When an intact tooth is present, root is exposed below the cementoenamel junction.  ¢ Incase of root piece, enough root structure is exposed to create purchase point.    ¢ When an intact tooth is present, the crown can be sectioned and removed first.    * This is mainly done when the path of removal of crown and roots are different.  ¢ Once the crown is removed, the roots are addressed.    * A hole is drilled in the tooth to engage the tip of the elevator. This hole is called ‘Purchase Point’    e lt must be deep enough to engage the elevator tip and must be drilled in healthy root to avoid fragmentation.  e Incase of multiple roots, they can be sectioned and removed separately.    e After the tooth is removed completely, wound debridement, curettage of granulation tissue, removal of loose and  sharp bony fragments, rounding off socket margins, gentle irrigation with normal saline and finally closure using    Fig. 13.24 Transalveolar extraction of impacted tooth: (a) IOPA showing impacted tooth, (b) Incision and flap reflection (Triangular flap),  (c) Bone removal, (d) Extraction socket (e) Closure, (f) Extracted tooth    Fig. 13.25 (a) Envelope flap, (b) Triangular flap, (c) Trapezoidal flap    enough to engage the tip of an instrument to be used  for elevation of the tooth.   Once the tooth is delivered, the sharp bony edges must  be smoothened using a bone file and the whole surgical  site must be thoroughly irrigated using copious amount of  sterile saline. The flap must be repositioned and sutured  into place.    If a treatment plan of complicated exodontia is  devised for a multirooted tooth, it is extracted with the  same technique as of single-rooted tooth. The only dif-  ference is that the tooth is divided using a bur to convert  into two or three single-rooted fragments (odontectomy).  Following incision and flap reflection, once the tooth is  converted into multiple single-rooted fragments, the  extraction procedure is carried out in a similar way as of  single-rooted tooth. Also, the immediate postoperative  procedures like smoothening of bony fragments, irriga-  tion, and closure also remains the same. The following  text describes different techniques of splitting a multi-  rooted tooth in different scenarios.   (a) Mandibular molar with intact crown: First step  involves the exposure of bifurcation by removing a  small amount of crestal bone. The tooth is usually  sectioned buccolingually to split the tooth into  mesial and distal halves (Fig. 13.27a). These halves  are then mobilized using a straight elevator and are  treated as two single-rooted teeth. These teeth are  then extracted with the help of mandibular premo-  lar forceps.   Alternatively, mesial root is sectioned using a bur  to convert the molar into single-rooted tooth  (Fig. 13.27b). The tooth along with distal root is  removed with the help of forceps followed by the  removal of mesial root. This mesial root is extracted  with the help of a Cryer elevator.   (b) Mandibular molar with lost crown: The roots are  separated in a buccolingual direction with the help of  a bur in two separate mesial and distal roots  (Fig. 13.27c). A small straight elevator is inserted in  between the roots and rotated to mobilize the roots  and elevate the mesial root. With the help of the Cryer  elevator, the mesial root is delivered out of the socket  by engaging the tip into the created purchase point  and rotating in a wheel-and-axle manner. The distal  root is then extracted by inserting the opposite mem-  ber of the Cryer instrument into the empty socket and  rotating again in a wheel-and-axle manner through  the interradicular bone.   (c) Maxillary molar with an intact crown: The roots of  maxillary molar are three in number and are diver-  gent. Sometimes, an open technique of extraction    causes less morbidity than the closed technique as  the extraction of maxillary molar requires exces-  sive force during forceps’ extraction. Once the  flap is raised, a small amount of crestal bone is  removed to expose the trifurcation. With the help  of a straight bur, the mesiobuccal and distobuccal  roots are sectioned horizontally at the level of tri-  furcation. This separates the two buccal roots con-  verting the molar into single-rooted tooth  (Fig. 13.27d). The molar with palatal root is then  extracted using the maxillary molar forceps with  gentle but firm bucco-occlusal forces. The two  buccal roots are then mobilized with the help of a  straight elevator. These roots are then delivered  out with the help of a straight or Cryer elevator.  The operator must take precaution to maintain  controlled force in an apical direction during  removal of these roots using the straight elevator  as maxillary sinus might be in a close proximity to  these roots. Uncontrolled and excessive force may  result in an oroantral communication or displace-  ment of the root into the sinus.   (d) Maxillary molar with lost crown: A small amount of  buccal bone is removed to expose the roots and is  divided into two buccal and_ palatal roots  (Fig. 13.27e). The roots are mobilized with the help  of a straight elevator and are extracted with the help  of bayonet forceps or Cryer elevators. Generally,  buccal roots are approached first followed by palatal  root.    During exodontia, once completed either by closed tech-  nique or by open technique, a few important things must be  kept in mind which are listed in Box 13.3 and the patient  should be instructed properly as listed in Box 13.4. During  exodontia, either closed or open, an assistant may be really  helpful and plays an important role during the procedure  (Box 13.5).    If multiple adjacent teeth are indicated for extraction, a few  key points are to be taken into consideration.    1. Soft tissue must be reflected to expose the crestal bone  around all the teeth in the quadrant.   2. If removal of any tooth requires excessive force, a small  amount of buccal bone should be removed to prevent  fracture and excessive bone loss.   3. All the teeth must be luxated well enough before  extraction.    Fig. 13.26 (a) A small portion of buccal bone is grasped along with — used to luxate the broken root, (c) Bone is removed from the buccal  the root in cases when the root is fractured at the level of alveolar bone _ aspect of the root using a bur  (Alveolar Purchase Technique), (b) A small straight elevator is being    Fig. 13.27 (a) Sectioning of tooth into mesial and distal halves, (b) Separation of mesial root from the tooth, (c) Separation of roots of mandibular  molar, (d) Buccal roots are sectioned from the tooth, (e) Separation of roots of maxillary molar   Visualize the socket by thoroughly drying the socket and the adjacent field   Inspect the socket for excessive bleeding which could be due to injured vessel  (forceful bleeding) or friable granulation tissue (steadily flowing blood) and curette  the socket   Inspect for foreign bodies like fragments of tooth, calculus tags, granulation tissue,  sharp bony fragments and remove using a mosquito artery if present   Compress the expanded socket with digital pressure (simple alveoloplasty). Not  recommended if implant is planned   Application of pressure pack to arrest bleeding using a moistened sterile gauze  rolled over cotton wool   Loose approximating sutures are placed following extraction to stop bleeding and  prevent food impaction if required.    Maintenance of pressure pack for 30 — 60 minutes (Initial clot is soft and friable. Clot  retraction takes 30-45 minutes)   Swallow the saliva and not to spit or rinse till 24 hours post extraction   Soft and cold diet for 24 hours so as not to disturb the clot and for vasoconstriction  Warm saline rinses after 24 hours to enhance healing of socket   Avoid smoking as it may dislodge the clot and lead to bleeding   No hot fomentation, only cold compressions in the immediate post-operative phase    4. Maxillary teeth are extracted first because. Role of Assistant during Exodontia  (a) Infiltration anesthesia has a more rapid onset in Helping surgeon to visualize or gain access to the surgical  maxilla leading to early start of the procedure. site  (b) Profound anesthesia is lost early in maxilla. Suction away blood, saliva and irrigating solutions  : i Helps in protecting the teeth of opposite side  (c) If mandibular teeth are extracted first, debris such as Stabilize the head of the patient  fractured crowns, bone chips, and portions of restor- Support the jaw of the patient ;  ative material may fall in the empty mandibular Psychological and Emotional support for the patient  sockets during extraction of maxillary teeth. ©Association of Oral and Maxillofacial Surgeons of India    5. Hemostasis must be achieved with maxillary sockets  before the extraction of mandibular teeth as the hemor- 80x 13.5 Role of assistant  rhage may interfere with mandibular surgery.  6. Extraction should be started with the most posterior  teeth as it allows the effective use of dental elevators to 9. If maxillary and mandibular teeth of one side are to be   simultaneously aiding in the extraction of both the teeth. Mandibular Canine.   This technique is known as Stobies technique. 10. Post-extraction, the buccal and lingual plates are reposi-  8. Canine is the most difficult tooth to extract, hence it tioned to the original position using digital pressure    11. If removable partial or complete dentures are planned,  the undercuts and bony spicules must be identified and  primary alveoloplasty must be carried out.   12. Soft tissue must be inspected for excessive granulation  tissue; if present, it should be removed as it may prolong  postoperative hemorrhage.   13. Papillae should be sutured in position. Primary closure  must not be performed at the cost of vestibular depth,  because if the vestibular depth decreases, it may inter-  fere with denture construction.    Ideally, when the apical one-third of the root (3-4 mm) is  fractured, it should be removed as it may act as a septic focus  or may result in the formation of cyst or other pathologies.  To extract these root tips, the two most important require-  ments are excellent light and excellent suction with a tip of  small diameter.   Once the fracture of root tip has been diagnosed, the  operator must reposition the patient to achieve proper visu-  alization and suction. Initially, closed technique must be  attempted; if unsuccessful, then the open technique must be  carried out for retrieval of root tip.    ¢ Initial attempt of root tip removal must be made by vigor-  ous irrigation of the socket using normal saline. Following  irrigation and suction, the socket must be inspected prop-  erly to check if the root has been removed or not.   e If unsuccessful, the root tip may be teased out of the  socket with the help of a root tip elevator (Fig. 13.28a).  The blade of the elevator is inserted in the periodontal  ligament space and the root is teased out of the socket  gently. Root tip elevator is a delicate instrument; hence  excessive force must be avoided as it may result in  bending or fracture of the blade. For larger fragments, a  small straight elevator may also be used.   e If the closed technique is unsuccessful, the operator  must shift to an open technique. A full-thickness muco-  periosteal flap is elevated and reflected to expose the  buccal bone. The buccal bone is removed using a bur to  expose the root fragment. The root is then delivered buc-  cally with the help of an elevator (Fig. 13.28b). The  socket is irrigated, flap is repositioned, and closure is  performed.   e If the buccal bone has to be preserved, a modification of  open technique can be performed. This technique is  known as open window technique. In this technique, once  the flap is reflected, the apical area of the root fragment is  identified and a hole is drilled with the help of a bur. This  exposes the root tip. An elevator is inserted through this    hole and the root fragment is guided out of the socket  (Fig. 13.28c and d).    However, if the risk during retrieval of root fragment  is comparatively more than the benefit of its removal, it is  advisable to leave the root in situ. If the surgeon decides to  retain the root, it should be documented and informed to the  patient. The criteria for retaining the root are highlighted in  Box 13.6. The policy of dealing with fractured apical root  tips of maxillary molars and the management of root tips dis-  placed into the antrum is elaborated in Chap. 24 of this book.    If permissible, extractions should be avoided during men-  struation because during this period there is a high level of  estrogen circulating in the blood streams which results in  increased tissue bleeding. Menstrual cycle could be a deter-  minant risk factor for alveolar osteitis. Also, both exodontia  and menstruation are stressful conditions, it is better not to  subject the patient to increased stresses [12].    Pregnancy: Second trimester is considered to be relatively  safer for carrying out minor oral surgeries. However, in  other trimesters, if the potential risk of retaining the tooth  outweighs the complications of performing the surgery, one  must plan to carry out extraction with the utmost care and  avoiding use of drugs and radiographs as much as possible.  Caution should be exercised to evaluate teratogenic potential  of drugs when prescriptions are warranted.   During first trimester, the fetus is at risk of developmental  defects if the extraction is carried out as it undergoes organo-  genesis. The best course of action is to prevent the patient  from all kinds of infection. During the third trimester, there  are chances of premature labor or even an abortion. However,  if an exodontia is planned, the patient must be kept in a left  lateral position. If the patient is maintained in a supine posi-  tion, there are chances of obstruction of venous return result-  ing in supine hypotension syndrome [13, 14].    Along with understanding the general principles of exodon-  tia, it is pivotal for a dental surgeon to thoroughly know the  phenomenon of healing of extraction wounds. An extraction  socket heals in a similar fashion as any other wound in the  body except for minor variations which occur due to the ana-  tomic structures in and around the socket.    Fig. 13.28 (a) The root tip elevator is inserted into the periodontal ligament space to elevate the root tip, (b) Open technique for removal of frac-  tured root fragment, (c) Open Window technique for removal of fractured root fragment, (d) Clinical picture of open window technique   If it is in close proximity to vital structures which may be injured during retrieval   If during exploration there are chances of its displacement to adjacent anatomical  spaces.    Blood present in the socket immediately after extraction  of tooth coagulates and red blood cells become entrapped in  the fibrin meshwork. This initial time period postextraction is  critical because if the clot dislodges, healing becomes delayed  and painful. Alterations in the vascular bed such as vasodila-  tation along with engorgement of blood vessels of periodon-  tal ligament and transport of leukocytes around the clot occur  during first 24-48 hours. A thick layer of fibrin covers the clot  which shows signs of contractions. This clot forms a scaffold  over which cells associated with healing grow.   In the first week following extraction, fibroblasts from  remnants of PDL begin to grow in the periphery of clot and  a thick layer of leucocytes gather over the clot. Osteoclastic  activity starts in the crest of alveolar ridge. Blood clot under-  goes organization by fibroblast and endothelial cell prolif-  eration, signaling the growth of small capillaries in the PDL  area.   Epithelial proliferation over the surface of the clot  increases during the second week of healing leading to a  more organized blood clot with new capillaries in the cen-  ter. Remnants of PDL undergoing degeneration are no lon-  ger visible. Margins of alveolar socket appear frayed due to  osteoclastic activity. Surfaces of small wounds epithelize  completely by this time.   By the third week, fibrin meshwork of the original clot  is replaced by mature granulation tissue. Young trabeculae  formed by osteoblasts derived from pluripotent cells of PDL  form around the periphery of wound. Crest of alveolar bone  appears rounded due to resorption. All kinds of wound epi-  thelize by this stage of healing.   Wound enters the final stage of healing in the fourth  week. There is deposition and resorption of bone of alveo-  lar socket which continues for several weeks. Newly formed  bone is poorly calcified; therefore, the bone after extraction  becomes radiographically evident only after 6-8 weeks.  Loss of crestal and buccal bone during transalveolar extrac-  tions leads to smaller alveolar ridges post healing.    Surgical procedures are associated with complications and  exodontia is no different. Various complications related to  exodontia are highlighted in Table 13.10.   e Use of resorbable oxidized cellulose (Surgicel) or gelatin  foam (Gelfoam).    Displacement of tooth in Antrum: Operator must be care-  ful while extracting maxillary molars to avoid displacement  of tooth/root into maxillary antrum. Excessive and uncon-  trolled force in the apical direction may lead to displacement  of tooth/root in the maxillary sinus. If displaced, it can be  retrieved by carrying out sinus exploration [16].   Displacement into adjacent spaces: Tooth/root might  get displaced into adjacent anatomic spaces. If it happens,  retrieval must be attempted. However, delayed retrieval can  also be done as foreign body reaction aids in localization of  the tooth/root [17].   Loss of tooth in pharynx: During exodontia, if the tooth is  lost in pharynx, one must get a chest radiograph done to rule  out aspiration. If the tooth is aspirated, bronchoscopy has to  be done for retrieval of tooth [18].   Injury to Temporomandibular Joint: It is mainly due to  the application of excessive forces while extracting mandib-  ular teeth and failure to support mandible. It can be avoided  by using mouth gags and supporting mandible properly.  Unsupported mandible may lead to dislocation of temporo-  mandibular joint. If occurred, it must be reduced immedi-  ately by mechanical reduction.    Complications  1. General complications  (a) Postoperative pain  (b) Hemorrhage  2. Problems with tooth being extracted  (a) Root fracture  (b) Root displacement in adjacent spaces or antrum  (c) Loss of tooth in pharynx  3. Injury to adjacent teeth  (a) Fracture or dislodgement of adjacent tooth restoration  (b) Luxation of adjacent tooth  (c) Extraction of wrong tooth  4. Injury to soft tissue  (a) Abrasion  (b) Puncture wound  (c) Tear of mucosal flap  5. Injury to osseous structure  (a) Fracture of alveolar process (Fig. 13.29)  (b) Fracture of maxillary tuberosity (Fig. 13.30)  6. Injury to adjacent structures  (a) Injury to regional nerves  (b) Injury to regional vessels  (c) Injury to Temporomandibular joint  7. Oroantral communication and fistula  . Fracture of mandible    9. Delayed healing and infection  (a) Infection  (b) Wound dehiscence  (c) Dry socket (Fig. 13.31)  (d) Osteomyelitis   2. Reactionary hemorrhage: it is seen a few hours  after surgery due to cessation of vasoconstriction of  damaged blood vessels.   3. Secondary hemorrhage: evident up to 14 days post-  operatively due to infection.    Mechanical reduction is done by an operator standing in  front of the patient and holding the mandible with both hands.  The thumbs should be placed over the external oblique ridge/  molars and the fingers holding the lower border of mandible.  Once held firmly, mandible should be moved in inferior, pos-  terior, and superior directions in a sequential manner [6].   Oroantral Communication and Fistula: Oroantral com-  munication (OAC) is a pathologic communication between  oral cavity and maxillary antrum; however, once epithelized,  it is termed as oroantral fistula (OAF). OAC must be closed  immediately if it is larger than 5 mm. In cases of OAF, fistu-  lectomy followed by closure is the treatment of choice [19].   Dry Socket: Dry socket or alveolar osteitis denotes delayed  healing with moderate to severe pain. Birn’s, hypothesis is  the most accepted explanation of dry socket. It states that  trauma and inflammation cause release of stable tissue acti-  vator from adjacent bony socket and soft tissue. Tissue acti-  vator converts plasminogen to plasmin which causes lysis  of blood clot and pain. Management of dry socket involves  relief of pain and ameliorating healing. A loose dressing  composed of zinc oxide and oil of cloves on cotton wool  is tucked into socket. Analgesic tablets and warm saline  rinses are prescribed and patient is kept on regular follow-up  (20, 21].   Osteomyelitis: It is ‘an infection of the bone and the bone  marrow which can be caused by an infection in the body  spreading in the blood stream from point of origin to the  bone’. Appropriate antibiotics for an extended period of time  is the line of treatment. In chronic cases, surgical debride-  ment becomes mandatory [22, 23].    Evolution never stops, this can be prominently justified by  the fact that a variety of new techniques and instruments  have been introduced to revolutionize the field of oral and    maxillofacial surgery. Some of the technological advance-  ments for dental extraction are highlighted here.   It is an electric unit which contains a controller box with  adjustable power settings and a periotome mounted on a  handpiece that is activated by a foot control. Use of standard  periotome is cumbersome as the force delivered is uncon-  trolled; however, this powered periotome is characterized  by complete control over the force delivery and the depth to  which it travels into the periodontal ligament space.   This device functions by wedging and severing mecha-  nisms. The thin metal blade of periotome is wedged into  the periodontal ligament space in a circumferential manner  severing the Sharpey’s fibers. Once most of the Sharpey’s  fibers are severed, tooth can be extracted with minimal lat-  eral movement. Hence, it allows flapless removal of tooth  maintaining the periosteal blood supply with reduced risk  of fracture of buccal or lingual cortical plate and decreased  postoperative pain and discomfort.    Golden—Misch [25, 26] based on Class I lever mechanics  designed the Physics Forceps to perform exodontia atrau-  matically. These forceps have a bumper which acts as a ful-  crum, is placed at the mucogingival junction on the facial  aspect applying steady, unrelenting pressure. Other than the  bumper, there is a lingual beak, which is positioned on lin-  gual or palatal root, making a single point contact with the  tooth.   Due to the pressure applied by the bumper, periodontal  ligament is traumatized resulting in the release of hyaluroni-  dase. Once the enough chemical breakdown of periodon-  tal ligament is achieved by the hyaluronidase, the tooth is  released from its attachment to the alveolus aiding in easy  removal. Physics forceps releases more hyaluronidase than  conventional forceps in a shorter period of time, resulting in  more efficient extraction of tooth with minimal trauma to the  alveolar bone.    13.16.3 Use of Implant Drills for Extraction  Prior to Implant Placement    Yalcin and colleagues [27] suggested a novel and minimally  invasive technique to perform exodontia with minimal risk  of damaging the thin buccal bone. The implant’s drills were  inserted into the root canals making the roots walls thin lead-  ing to extraction with application of much less force.    Laser offers a noncontact and low vibration bone cutting  without any visible, negative, and thermal side effects.  Er: YAG laser can be used for surgical extractions to ablate  the covering bone layer by layer exposing the portion of the  root. Once the tooth/root is uncovered, they can be conven-  tionally removed [28]. However, laser osteotomies are time  consuming and require constant suctioning to achieve a dry  field for effective cutting.    Piezo surgery is very effective in bone cutting as it works  selectively without injuring any soft tissue structure. Hence,  it is very advantageous over the conventional burs which  have potential to cause injury to soft tissue. Also, a clearer  field is obtained while using piezo surgery. However, the  time required while using piezo surgery is more [29].    Patient is subjected to an extraction of a tooth and during the   lar socket. The tooth is nowhere to be seen in the oral cavity    Signs and symptom of aspiration depends on the site  where the tooth is present. A laryngotracheal obstruction    presents with dyspnea, cough, and stridor. It also results in  difficulty in breathing with or without cyanosis. Chocking is  also characterized by the sign of hands clutched to the throat,  depending on whether the chocking is partial or complete.  However, tooth in bronchus is associated with cough, dimin-  ished airway entry, dyspnea, and wheezing. Sometimes, the  patient may remain asymptomatic for several months if the  aspirated tooth is very small. However, long-term retention  may result in late complications including postobstructive  pneumonia, atelectasis, bronchiectasis, pneumothorax, hem-  orrhage, lung abscess, vocal cord paralysis, and death.  ¢ Ingestion.   Generally, the passage of ingested tooth through the  gastrointestinal tract is uneventful. In cases of obstruc-  tion, the most frequently noticed symptoms are dysphagia  and odynophagia. Esophageal obstruction presents with  gagging, coughing, chest pain, drooling of saliva, nausea,  hematemesis, regurgitation, muscular incoordination, and  incessant twitching. Abdominal pain is one of the symp-  toms other than fever, nausea, vomiting, and abdominal  distensions in cases of abdominal impactions.   — If the patient has visible Airway Obstruction, he must  be asked to cough and Heimlich maneuver must be  attempted to relieve obstruction.   — If the object is dislodged, it should be identified and  confirmed. If not, then cricothyroidectomy must be  done to secure airway. If not possible in the clinic, then  the patient must be rushed to the emergency unit for  securing airway.   — In cases with no airway obstruction, the entire oral  cavity must be examined. If the object is found, it  should be identified and confirmed.   — If the object is not found in the oral cavity, the patient  must be subjected to Chest radiography and  Ultrasonography Abdomen.   — For radiolucent objects, bronchoscopy and Computed  Tomography of Chest and Abdomen are preferred.   — If the object is in respiratory tract, bronchoscopy must  be planned for retrieval.   — If the object is in Esophagus, Endoscopic removal  must be done.   — If the object is in Gastrointestinal tract (GIT), beyond  esophagus, patient must be monitored for 2 weeks with  serial radiographs. Stool examination must be done till  the object is expelled.   — If the object is not retrieved, radiographic examination  must be repeated.    — Radiographic examination reveals the absence of  object in GIT, it should be assumed that the object has  passed out. The patient must be reassured, however,  must be kept on follow-up.   — If the radiographic examination reveals the presence of  object in GIT, the patient must be referred to a gastroen-  terologist for removal either by surgery or by endoscopy.    A 33 year-old male reported with a chief complaint of a firm,  diffuse swelling of size approximately 2 x 1 cm in left man-  dibular body region with occasional pus discharge from the  extraoral skin fistula (Fig. 13.33a). He also complained of  associated intermittent pain and fever.   On further questioning, he revealed that he had visited a  private clinic 6 months back for the complaint of dental  caries. Following clinical and radiographic examination,  the dentist had planned to extract the tooth. To the patient’s  knowledge, the extraction was done uneventfully, but one  root was lost during the procedure. Patient was prescribed  with antibiotics and analgesics for a period of 5 days. The  patient became apprehensive and uneasy in the following  days. The fear of further complications kept him from visit-  ing the dentist again and the condition went on worsening.  Finally, after 6 months, he reported to an oral and maxil-  lofacial surgeon.    Investigations  An orthopantomogram was taken which revealed a displaced  root fragment in left first molar region. (Fig. 13.33b).   After obtaining patient’s consent, under antibiotic coverage  and local anesthesia, surgical exploration was done through  the existing skin fistula extraorally. With the digital pressure,  the root piece was delivered out (Fig. 13.33c). Curettage  and debridement was done carefully and patient was kept  on follow-up. Closure was not performed. Antibiotics, anal-  gesic, and nonsteroidal anti-inflammatory drugs were pre-  scribed postoperatively. Patient recovered without further  incident. In the late period of follow-up, no complication  was observed except extraoral scarring.    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Open Access This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.  org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropri-  ate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.    The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in    a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.   Even as the scope of practicing oral and maxillofacial sur-  gery grows and continues to evolve, the mainstay of practice  remains dentoalveolar surgery. In this area, the surgical  removal of impacted teeth is one of the commonest proce-  dures that is performed. Among the teeth that are commonly  impacted, the mandibular molars rank first, followed by the  maxillary third molars and the maxillary canines. Less com-  monly, impaction of other teeth such as the mandibular  canines, maxillary and mandibular premolars, and the sec-  ond molars are also seen.    The term impaction comes from the term “impactus,” which  is of Latin origin. Its general usage refers to the failure of an  organ or structure in achieving its normal position because of  an abnormal mechanical condition.   Archer [1] defined impacted tooth as a tooth that is par-  tially or completely unerupted and is positioned against  another tooth or bone or soft tissue so that its further eruption  is unlikely.   Lytle [2] proposed a definition that is intimately related to  that of Archer. An impacted tooth is a tooth that has failed to  erupt into its normal functional position beyond the time  usually expected for such appearance. Eruption may have  been prevented by adjacent hard or soft tissue including  tooth, bone, or dense soft tissue.    Electronic Supplementary Material The online version of this chap-  ter (https://doi.org/10.1007/978-98 1-15-1346-6_14) contains supple-  mentary material, which is available to authorized users.   Principal, Professor and Head, Department of Oral and  Maxillofacial Surgery, Pushpagiri College of Dental Sciences,  Tiruvalla, Kerala, India    © The Association of Oral and Maxillofacial Surgeons of India 2021    Andreasen et al. [3] defined impaction as a cessation of  the eruption of a tooth caused by a clinically or radiographi-  cally detectable physical impediment in the eruption path or  by an ectopic position of the tooth.    e An unerupted tooth is the one lying within the jaws,  entirely covered by soft tissue, and partially or completely  covered by bone. This tooth is undergoing the eruption  process and will probably erupt into occlusion based on  clinical and radiographic findings.   ¢ A partially erupted tooth is one that has failed to erupt  fully into a normal position. The term implies that the  tooth is partly visible or in communication with the oral  cavity.   e An impacted tooth is a tooth which is prevented from  completely erupting into a normal functional position.  The reason may be due to lack of space, obstruction by  another tooth, or an abnormal eruption path.    Archer observed that the following types of teeth, in  order of frequency, are most likely to be impacted:  maxillary third molars,    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1-15-1346-6_14    Although the standard management strategy is usually con-  sidered to be surgical removal of the impacted tooth, the fol-  lowing methods listed below also should be considered  depending upon the case:    1. Conservative method—Leaving the tooth alone with reg-  war follow-up clinically and radiographically. For  instance, a deeply asymptomatic third molar may be left  as such especially in an older age group patient.   2. Operculectomy—This procedure can be considered in a  mandibular third molar that has partially erupted, and has suf-  ficient space to come into occlusion, but is prevented from  doing so by thick overlying mucoperiosteum. If the tooth still  fails to erupt fully, it has to be considered for removal.   3. Autogenous transplantation—Occasionally, the third  molars can be considered for autogenous transplantation,  usually to a first molar socket site. Because of the low  success rate with such procedures, it is not widely used  except in special circumstances.   4. Orthodontically guided eruption—This is usually suited  to impacted maxillary and mandibular canine teeth.  Orthodontic guidance enables the tooth to reach a func-  tional position within the arch. This technique can also be  applied to impacted premolars and, in some instances,  even impacted mandibular molars.    The benefits of prophylactic surgical removal of impacted  third molars that are disease-free is quite controversial [4-6].  There are opinions that retaining the teeth may be more cost-  effective than prophylactic removal, at least in the short to  medium term. Nevertheless, there may still be clinical situa-  tions that demand prophylactic surgery. Each clinical sce-  nario needs an individualized evaluation and the consequences  of all management techniques must be discussed with the  patient. Thomas Dodson in [4] brought out a classification  based upon the presence/absence of symptoms and the pres-  ence/absence of disease. He proposed to use this method to  decide on the removal vs retention of third molars.    14.3 Etiology of Impaction  Generally, the third molars or the wisdom teeth are the last    teeth to erupt and they erupt between 18 and 25 years of age.  Since they erupt at about the time when the youth goes off   A number of theories have been put forth to explain the  phenomenon of impaction. The following are the most com-  monly accepted ones:-   3. Delayed maturation of the third molar—dental develop-  ment of the tooth lags behind the skeletal growth and  maturation.   4. Incidence of extraction of permanent molars is decreased  in the mixed dentition period, providing less room for  eruption of third molars. This is very pertinent in the pres-  ent day due to better awareness of the population and  dental treatments are started early in childhood.   5. Inadequate development of jawbones due to consumption  of more refined food which causes reduced functional  stimulation for the growth of jaw bone.    Berger [7] listed the following local causes for impaction  of teeth:    1. Irregularity in the position and pressure of an adjacent  tooth.   2. The increased density of the overlying or surrounding bone.  3. Continued chronic inflammation with subsequent  increase in density of the overlying mucous membrane.   . Acquired diseases such as necrosis due to infection or  abscess.    Impaction may also be found with no local predisposing  conditions cited above.   According to Berger, the following are the systemic  causes of impaction:   (b) Postnatal causes—Rickets, anemia, congenital syphilis,  tuberculosis, endocrine dysfunction, and malnutrition.   Despite the fact not all unerupted/impacted teeth cause prob-  lems, all have that potential. Based on extensive clinical  studies, indications for removal have been identified.   1. Pericoronitis and Pericoronal abscess (Fig. 14.1a, b,  c)—This is the most common cause for extraction of  mandibular third molars (25-30%). Pericoronitis is fre-  quently found to be associated with distoangular and    Fig. 14.1 (a, b, c) Impacted right mandibular third molar with pericoronitis causing extraoral abscess (a) Extraoral abscess (Yellow arrow), (b)  Impacted 48 with pericoronitis (yellow arrow), (c) OPG showing impacted 48 (Yellow circle)   2. Dental Caries—Incidence of caries of the second  molar or third molar is about 15%. The reason for this  high incidence is attributed to difficulty to perform  oral hygiene measures in the third molar area  (Fig. 14.2).   3. Periodontal diseases—Repeated food impaction and  collection of food debris between the impacted third  molar and the erupted second molar can lead to peri-  odontal disease and subsequent bone loss. This weakens  the bone support for the second molar and can cause  pulpo-periodontal disease in the second molar  (Fig. 14.3).   4. Orthodontic reasons  (a) Crowding of incisors: Third molars has the potential Fig. 14.2. IOPA X-ray of Horizontally impacted tooth 38 with dental   turn can cause mandibular incisor crowding. Hence,  removal of third molars has been recommended dur-  ing or after orthodontic treatment. The hypothesis  that the mesial pressure from the third molars is  transferred through the contact points resulting in  the narrow contacts of the lower incisors is slipping.  Contemporary studies have questioned this hypoth-  esis. However, it is still believed by certain clini-  cians, and third molars may be removed for these  reasons.   (b) To facilitate orthodontic treatment—Since the  recent trends in orthodontics prefer non-extraction  modalities of treatment, distalization of molars has  become ever more popular, particularly with regard  to Class II malocclusions. In such cases, in order to  expedite the distal movement of maxillary molars,    the impacted or erupted maxillary third molar tooth — @aggociation of Oral and Maxillofacial Surgeons of India  may be extracted.    Fig. 14.4 OPG showing impacted 38 associated with dentigerous cyst  of mandible involving the left ramus, angle, and body    To facilitate orthognathic surgery—Removal of third  molars should be considered in the presurgical prepara-  tion for orthognathic surgery. Making bone cuts in  Bilateral sagittal split osteotomies (BSSO) is easier after  third molars are removed. To ensure that adequate bone  exists in this region, these must be extracted at least one  year before the planned osteotomy.   Odontogenic cysts and tumors—Cysts and tumors may  develop from the retained follicle around the impacted  tooth (Fig. 14.4). To prevent this, extraction of asymp-  tomatic third molars is recommended.   Unexplained pain—Sometimes, unexplained pain may  be alleviated simply by removing impacted teeth,  although the mechanism is still unclear. However, the  pros and cons must be discussed with the patient.  Resorption of the adjacent tooth root—Pressure from  the impacted tooth can cause the root of the second  molar to resorb. When this is identified, the third molar  must be removed as early as possible to avoid further  damage.   For placement of dental prosthesis—The removal of  impacted teeth under dental prosthesis must be assessed  carefully, with the evaluation of risk versus benefits.  Removal may be done for teeth that are superficial.  However, sometimes the impacted tooth may lie deep  within the mandible and in such cases, the tooth is better  off left in situ.   Prevention of jaw fracture—For those engaged in  contact games, it may be better to prophylactically  remove the impacted third molars, as this area may  be prone to fracture due to lowered bone resistance  (Fig. 14.5).   Infection of deep fascial spaces—When pericoronitis is  associated with impacted tooth, infection can track into  deep fascial spaces.    Fig. 14.5 OPG showing impacted left mandibular third molar in  inverted position associated with supernumerary (red circle) with frac-  ture of left angle mandible (yellow arrow). Note multiple impacted  supernumeraries (yellow circles) and fracture of right condyle (red  arrow)    12. To remove a potential infection source (e.g. prior to  administration of radiotherapy)—Teeth which are at risk  of infection like partially erupted third molar tooth may  lead to local complications like osteoradionecrosis or  systemic complications like endocarditis. Removal must  be considered for these cases as well as other procedures  such as chemotherapy, organ transplantation, or inser-  tion of alloplastic implants.   13. Removal for autogenous transplantation—Even though  this was a very popular procedure in the past, it fell into  disrepute due to unpredictable results. However, it is  worth considering when indicated for first molar  replacements.    1. Compromised systemic status—It may not be advisable  to undertake surgical removal of impacted third molars in  patients with uncontrolled or poorly controlled systemic  disease, as they can develop complications during or after  the procedure. Hence, a proper history, physical examina-  tion, and, if needed, appropriate laboratory investigations  must be performed.   2. Advanced age—Bone sclerosis increases with advancing  age. This leads to poor healing, a larger defect size, and  increased difficulty of the procedure. Risk of mandibular  fracture is also high in these cases.   3. Damage to any adjacent structures—If the inferior alveo-  lar canal is in close contact with the impacted tooth, inad-  vertent damage can result in paresthesia.   4. Questionable status of the second molar—If the sec-  ond molar is badly decayed and unrestorable, remov-  ing it may allow the third molar to come into a    Fig. 14.6 Coronal section of mandible in the region of the third molar  showing a thick buccal alveolar bone and a thin lingual plate    functional position. The third molar may also serve as  a bridge abutment. Such cases require multidisci-  plinary evaluation with the prosthodontist and  endodontist.   5. Deeply impacted third molars which do not appear to be  associated with local or systemic pathology must not be  removed.    The mandible comprises of a body which is horseshoe  shaped and has the ramus on either side, which are flat and  broad rami. Each ramus has two processes at the superior  end—the coronoid process, which is more anterior, and  condylar process, which is continuous with the posterior  border.   The mandibular third molar tooth is usually present at  the distal end of the mandibular body, which adjoins a thin  ramus. The body-ramus junction is a weak area that can  fracture if excessive force is employed during the eleva-  tion of the third molar. The tooth lies between the buccal  cortical plate, which is thick, and the thin lingual cortical  plate (Fig. 14.6). In most instances, the thickness of the  lingual plate may be less than 1 mm, and the tooth may  get displaced into the lingual pouch if untoward force is  applied.    Fig. 14.7 Radiograph showing the proximity of impacted third molar  roots to the mandibular canal    The mandibular canal lies beside or below the third molar  roots. Usually, the canal lies slightly buccal and apical to the  third molar roots, but this varies frequently (Fig. 14.7). The  canal contains the inferior alveolar neurovascular bundle  including the artery, vein, and nerve within a sheath of fascia.  The third molar roots may sometimes be indented by the  canal, but actual penetration is rare. In these cases, attempt-  ing to elevate fractured root tips may result in the displace-  ment of the tips into the mandibular canal. If the canal vessels  get injured by instruments or forceful intrusion of the tooth  roots, profuse hemorrhage may result.    This is a depressed roughened area behind the third molar  bounded by the buccal and lingual alveolar ridge crests. The  retromolar fossa is a shallow depression that occurs just lat-  eral to the retromolar triangle. Mandibular vessel branches  may emerge at the fossa or triangle and can be injured during  surgical exposure of the third molar region if the incision is  not taken laterally. This can result in brisk hemorrhage  (Fig. 14.8).    The facial artery and anterior facial vein are related to the  mandibular body, anterior to the masseter muscle, where  they cross the inferior border of the mandible. They lie below    the second and third molar teeth and may be injured when a  buccal incision is placed at an inferior level. To avoid this, it  is best to start the incision at the sulcus depth and move  upward toward the tooth.    Inferior alveolar vessel  ©Association of Oral and Maxillofacial Surgeons of India    Fig. 14.8 Schematic diagram showing the retromolar vessel emerging  through retromolar foramen    Fig. 14.9 Schematic diagram  showing coronal section  through the third molar region  and the relationship of  important anatomical  structures    The lingual nerve often runs below and behind the third molar,  and contacts the periosteum over the lingual cortex at a sublin-  gual level. Cardinal anatomic studies have shown the close rela-  tion of the lingual nerve to the lower third molar region [8, 9].    The lingual nerve usually lies 2.3 mm below the lin-  gual alveolar crest, and 0.6 mm medial to the mandi-  ble, when viewed from a frontal plane.    Since the lingual nerve is close to the third molar, it is at  risk of damage during surgical removal of the tooth. This  may lead to anesthesia of the tongue in its anterior two-  thirds, and also loss of taste sensation in this area.   The surgeon should also be aware of the course and direc-  tion of the mylohyoid and long buccal nerve to prevent inad-  vertent injuries to these nerves (Fig. 14.9).    The bone trajectories of the mandible, referred to as grains,  course in a longitudinal direction. Even though the technique  of chisel and mallet has almost become obsolete, it is impor-  tant to know the bone trajectories. On the buccal side, a hori-  zontal chisel cut that is oriented parallel to the superior  border may cause extensive splitting till the first molar region  due to the grain direction. To prevent this, the operator must  make a “vertical stop cut” (Fig. 14.10), with the bevel ori-    Grains of mandible  ©Association of Oral and Maxillofacial Surgeons of India    Tooth displaced into lingual pouch  ©Association of Oral and Maxillofacial Surgeons of India    Fig. 14.11 Whole tooth displaced into lingual pouch beneath the  mylohyoid muscle    ented posteriorly, just distal to the second molar. The chisel  must be angulated correctly at all times to avoid fracture of  mandible distal to the third molar.    Since the lingual pate is very thin, it may be perforated by the  apices of lower third molar roots. If the roots are fractured,  attempting to elevate may cause them to be displaced into the  “lingual pouch,” from where it will be difficult to retrieve.  The entire tooth also may rarely be pushed into the lingual  pouch (Fig. 14.11).    To assess surgical difficulty, several classifications have been  proposed, which can help formulate a treatment plan that is  efficient and has minimum morbidity. Either the periapical  radiograph or the Orthopantomogram is used to analyze the  impacted tooth for its classification.  The most commonly used are:-  1. Angulation [10] of the impacted tooth (Fig. 14.12)  (George Winter classification).  Vertical,  Mesioangular,  Horizontal,  Distoangular,  Buccoangular,  Linguoangular,  Inverted,  Unusual  2. Relationship between the impacted tooth and the anterior  ramal border {11]—This assesses the amount of space  present between the anterior border of the ramus and the  distal wall of the second molar. This indicates the effec-  tive space available for the tooth to erupt (Fig. 14.13).  Class I—There is enough mesiodistal space between the  anterior border of ramus and second molar to accommo-  date the third molar.  Class II—Space between anterior border of the ramus  and second molar is less than the mesiodistal width of the  crown of the third molar.  Class III—No mesiodistal space available and the third  molar is almost completely within the ramus.  Class III impactions present greater difficulty in removal.  3. Depth of the impacted tooth and tissue type that overlies  the tooth (Pell and Gregory Classification based on occlu-  sal level of the tooth)—i.e. soft tissue, partial bony, or  complete bony impaction (Fig. 14.14).  Position A—The highest point of the tooth is at the same  level of the occlusal plane or above it.  Position B—The highest point of the tooth is above the  cervical line of the second molar but below the occlusal  plane.  Position C—The highest point of the tooth is well below  the cervical line of the second molar (Figs. 14.15 and  14.16).  4. Type of tissue that lies over the tooth—.e. soft tissue, par-  tial bony, or complete bony impaction.  5. Level of Eruption  (a) Erupted.  (b) Partially erupted.  (c) Unerupted.    Fig. 14.13 Pell and Gregory Classification based on relationship to the anterior border of ramus    Position A Position B Position C  ©Association of Oral and Maxillofacial Surgeons of India    Fig. 14.14 Pell and Gregory Classification based on relationship to the occlusal plane of the impacted tooth to that of the second molar    Fig. 14.15 Examples of impaction showing combination of angulation A depth—an impacted tooth easy for removal. (b) Distoangular impac-  of tooth, relationship to anterior border of ramus and depth of impac- tion in Class III ramus relation and Position B depth—an impacted  tion. (a) Mesioangular impaction in Class I ramus relation and Position tooth difficult for removal    Fig. 14.16 OPG showing impacted mandibular third molar displaying  only crown of the tooth with no roots visible (yellow arrow) with close  proximity to inferior alveolar canal in a 52-year-old male. Surgical  removal of 38 was attempted without taking CT or CBCT. During sur-  gery, there was accidental fracture of left angle for which internal fixa-  tion has to be done. Note impacted 18 and 28    Presence of an impacted third molar must be diagnosed sys-  tematically using the patient’s chief complaint and history,  clinical examination, and appropriate investigations.   The impacted third molar must be evaluated both clini-  cally and radiographically prior to surgery for successful and  speedy removal. Ideally, a periapical radiograph must be  taken and an OPG must be added if the intraoral radiograph  does not provide enough information about the tooth or adja-  cent structures.   Manvel et al. has [12] developed a simple format for eval-  uation of third molar impactions.   This comprehensive format is ideal for residents in oral  surgery during their learning years. Using this format, third  molar impactions may be analyzed, and difficulty level may  be assessed and anticipated. Residents can judge problems  that they may encounter during the procedure and can evalu-  ate the patient better postoperatively.    This includes taking the patient’s history, clinical examina-  tion extraorally and intraorally.    1. History taking  Complaints of the patient—Impacted teeth are usually  asymptomatic and patients are aware of their existence  only when told by the dental practitioner. Symptoms, if  any, are usually due to acute or chronic pericoronitis, or  due to acute pulpitis secondary to dental caries.   and swelling related to infection. The lower lip is tested for   anesthesia or paresthesia. The regional lymph nodes must be  assessed by palpation for any tenderness or enlargement.  3. Intraoral examination—The following points are noted:   (a) Mouth opening—The ability of the patient to open  the mouth is analyzed, and any trismus, fibrosis, or  hypermobility of the joint is noted. The size of the  mouth (microsomia/macrosomia) is also checked.  Third molar access may be restricted if the mandible  is retrognathic, while a prognathic mandible offers  good access.   (b) General examination of oral cavity- oral mucosa,  teeth, and oral hygiene.   (c) Examination of the third molar area for signs of peri-  coronitis and state of eruption of the tooth.   (d) Condition of the impacted tooth- presence of caries,  dental fillings, and internal resorption (which may  resemble caries). The angle of the tooth and locking  beneath second molar must be noted and confirmed  with appropriate radiographs.   (e) Condition of first and second molars—presence of  caries, fillings, or crowns; root canal treatment may  put the second molar at risk of fracture and the patient  must be warned of this. Distal periodontal pocketing,  root resorption, and absence of the second molar  must also be noted.   (f) Space present between the second molar distal sur-  face and the ascending ramus: A small distance  makes access difficult, and a large distance makes the  tooth more accessible. For maxillary teeth, the dis-  tance between the second molar and tuberosity must  be considered. Access can also be decreased by distal  tilting of second molar.   (g) Adjacent bone may develop infection, which can  spread along the mesial surface of the tooth and affect  the second molar, which would then require extrac-  tion. Infection/osteomyelitis can spread to the ramus  in the case of distoangular impacted third molars,  through recurrent submasseteric abscesses in this  region.   (h) Systemic skeletal diseases may cause pathological  complications which should be noted. For instance,  conditions such as osteogenesis imperfecta and  osteosclerosis may cause fractures during the proce-  dure. In acromegaly, the mandibular bone is massive  which makes the procedure difficult because the  mandible consists of massive bone. In Paget’s disease  also tooth removal is difficult as the bone is affected  by resorption and repair.    (i) Presence of cysts and tumors—The impacted tooth  may be associated with eruption cysts or large odon-  togenic cysts can occur in relation to impacted tooth.  By and large, they cause displacement of the tooth.  Benign and malignant tumors such as ameloblastoma  may also be found involving the tooth. Odontomes  may also be present in relation to the third molar.    Any factor that increases the difficulty of third molar removal  can be analyzed from the preoperative radiograph.  The following radiographs may be used for analysis:    An essential criterion for a good film is that the buccal  and lingual cusps of the second molar must be super-  imposed on each other in the same vertical and hori-  zontal plane. This appearance of the second molar is  referred to as ‘enamel cap’.    1. Periapical radiograph: The radiograph should include  the entire third molar tooth along with the investing bone.  It should also show the anterior border of ramus, the sec-  ond molar, and the inferior alveolar canal.   2. Lateral oblique view of the mandible: This radiograph is  inevitably distorted because the opposite side of the man-  dible is rotated away from the beam during film exposure.  Therefore, it is inferior to the periapical X-ray, but it has  its use in certain clinical situations:  ¢ When periapical X-ray cannot be taken due to trismus   or retching.  ¢ To provide supplementary information like height of  mandible in the region of the third molar, or bone  height beneath a deeply buried tooth. The latter is use-  ful to assess the risk of pathological fracture in thin  mandible, or in cases of cysts or tumors.  Since the introduction of OPG, the use of lateral oblique  view is limited and is only considered when an OPG is  unavailable.   3. Orthopantomogram (OPG): This provides the same  information as the lateral oblique view, with less distor-  tion. The OPG is now used routinely to precisely the  locate impacted teeth.    opaque line that is formed by the external oblique ridge,  the ease of access can be ascertained. A vertical line  implies poor access and a horizontal line, good access.  Position and depth of impacted tooth—These can be  evaluated using Winter’s technique of WAR lines  (described by George Winter). WAR refers to three  imaginary lines drawn on the radiograph, namely, the  “white,” “amber,” and “red” lines (Fig. 14.17a, b).   The first line or “white” line extends across the  occlusal cusp tips of the erupted mandibular molars and  is drawn distally over the third molar region. This line  indicates the axial inclination of the impacted tooth. For  example, the white line is parallel to the occlusal surface  of the third molar if the tooth is vertically impacted,  whereas, the “white” line converges with the occlusal  surface in front of the tooth in distoangular impactions.   The “white” line also indicates the depth of the tooth  as compared to the erupted second molar.   The second “amber” line extends from the bone sur-  face distal to the third molar and is drawn to the interden-  tal septum crest between the first and second molar. When  drawing this line, it must be clearly differentiated from the  external oblique ridge shadow, which can lie above and in  front of the posterior end of the ‘amber’ line. The poste-  rior end is the shadow cast by the bone in the retromolar  fossa and not the external oblique ridge. The “amber” line  shows the margin of the alveolar bone enclosing the tooth.  Hence, when soft tissues are reflected, the portion of the  visible tooth will be the part that was lying above and in  front of the “amber” line in the radiograph. The rest of the  tooth will be covered by bone.   The third line or “red” line assesses how deep the  impacted tooth is within the mandible. This is drawn by  dropping a perpendicular from the “amber” line to the  point at which the elevator will be applied to elevate the  tooth (an imaginary point). This point usually lies on    marked in the periapical X-ray. (b) WAR lines drawn on a distoangu-  larly impacted mandibular third molar. Note that in distoangular impac-    the mesial surface of the impacted tooth, at the cemen-  toenamel junction, except in the case of distoangular  impactions. The longer the red line, the more deep the  tooth is impacted, and the surgical procedure will be  more difficult.   Root pattern of impacted tooth—The number, shape,  and curvature of roots are noted. Hypercementosis is  noted if present. If the root apex takes a sharp bend  toward the X-ray beam, it may appear blunt and short on  the image. This finding should therefore be investigated  in more detail.   The type of root morphology dictates the difficulty of  the surgical procedure. If root development is limited, it  can result in a “rolling” tooth, which is challenging to  remove.   Shape of crown—If the tooth has prominent cusps, or  large, square crowns, the difficulty increases as com-  pared to small crowns and flat cusps. The size and shape  of the crown of third molar is particularly important with  regard to the “line of withdrawal.” Sometimes, the path  of crown removal can be obstructed by the second molar  crown (Fig. 14.18).   In these cases, the cusp of the third molar appears to be  superimposed on the distal surface of the second molar  in the radiograph. If elevation is attempted by applying  force on the mesial surface of the impacted tooth, the  second molar may get displaced from the socket, and  there is a risk of mandible fracture. The risk is especially  high for second molars with conical roots. In such cases,  sectioning the third molar is advisable.   Texture of the investing bone—As age advances, the  bone undergoes sclerosis and becomes less elastic. The  bone texture can be analyzed by visualizing the size of  the cancellous spaces and the bone density. Bone that    tions, the perpendicular “red” line should be dropped to the  cementoenamel junction on the distal side of the impacted tooth and not  on the mesial side as in other angulations    Fig. 14.18 “Locking of the crown” of impacted third molar by the  second molar. Note that the cusp of third molar is superimposed upon  the distal surface of second molar    has large spaces and fine structure is generally elastic.  On the contrary, sclerotic bone has small spaces and  dense bone structure. Dense bone does not expand easily  during luxation and more bone removal may be required.  (f) Inferior alveolar canal—Although radiographs often  show the canal crossing the third molar roots, this is usu-  ally due to superimposition. Sometimes, however, this  may indicate grooving or perforation of the root.. The  classical papers by Howe and Poynton [13] and Rood  and Shehab [14] have given predictable signs to assess  the relationship between the nerve and the third molar  roots.  1. If there is a band of reduced radio-opacity that crosses  the roots, and this band coincides with the outline of    the inferior alveolar canal, this is a sign that the tooth  root may be grooved by the canal. This sign reflects  the lesser amount of tooth structure lying between  the X-ray source and the film.   2. The roof and floor of the canals are formed of com-  pact bone, which is indicated by continuous, parallel  radio-opaque lines. If the lines lose continuity, it is an  indication that the root is grooved by the inferior  alveolar canal. These grooves usually form on the  lingual side of the roots.    If the third molar is found to be in close relationship with  the inferior alveolar canal, the patient should be informed in  advance regarding the likelihood of impairment of labial  sensation following the surgical removal of the tooth. This  should be recorded in the case record and in the consent  form. In such cases, authors have recommended coronec-  tomy (partial tooth removal, intentional root retention, par-  tial odontectomy) as an option. However, this technique  cannot be considered foolproof and long-term studies are  required to know the success of coronectomies [15, 16]    3. In cases where the radiolucent band crosses the apex (g) Position, root pattern, and nature of crown of second  of the root and if only the upper white line is broken, molar.  a notching of the root is present. The space between the distal surface of the second molar  4. Characteristic narrowing of the radiolucent band and the mesial surface of the impacted third molar has an  with loss of white lines is suggestive of perforation of effect on the ease of removal of the third molar. The closer  the root by the inferior alveolar canal. the third molar is to the second molar, the more challeng-  The following signs have been demonstrated to be ing the surgery becomes. If the long axis of the second  associated with a significantly increased risk of nerve molar is tilted distally, it is more difficult to remove.  injury during third molar surgery: (Fig. 14.19a, b, c) Cone beam computed tomography (CBCT) (Fig. 14.20a,  e Diversion of the inferior alveolar canal (IAC). b, c) CBCT is now available for dental use and offers  e Darkening of the root where crossed by the canal. low dose imaging in multiple planes.  ¢ Interruption of the white lines of the canal. Using this modality, accurate three-dimensional imag-  ing can be done to determine the relationship between  In the presence of any of the above findings, great care the roots of the third molar and the inferior alveolar  should be taken in surgical exploration and the decision nerve (IAN). The recent recommendation is that when  to treat is carefully reviewed. If on the initial panoramic the OPG suggests a close relationship between the roots  radiograph there is an evidence of a close relationship of the lower third molar and IAN, cone beam CT scan-  between the roots of the lower third molar and the IAC, ning should be advised [17-19]. The effective dose from  a second radiograph should be taken using different pro- CBCT is comparatively less than the conventional CT  jection geometry. scan and also at a lower expense.  a Superimposed b Grooved c Within    Fig. 14.19 (a—c) Radiographic relationship of third molar root to infe-  rior alveolar nerve (a) Cortical outline of the canal is intact. This prob-  ably represents superimposition only. (b) There is loss of cortical  outline of the nerve canal. The nerve may be grooving the tooth. (c)    There is loss of cortical outline as well as narrowing and deviation of  the nerve canal, denoting an intimate relationship of the nerve with the  tooth and possibly perforation of the tooth roots by the nerve    Fig. 14.20 (a) CBCT Panoramic view showing the relationship of 38  and 48 to the inferior alveolar canal (IAC) [red line]. The changing  relationship of the IAC to 48 can be noted in (b—d). Relationship of IAC    Locating the lingual nerve clinically and by imaging is more  challenging. Lingual nerve injury although less common than  inferior alveolar nerve (IAN) injury is often more unbearable to  the patient. Patients find it difficult to tolerate lingual nerve  damage, including loss of taste and sensation of tongue, as  compared to IAN damage. Unlike the IAN, the lingual nerve is  not usually imaged prior to third molar surgery. In cases where  distal, distolingual, and lingual bone is to be removed, tech-  nique of raising the lingual flap and protecting the lingual nerve  by a broad smooth lingual flap retractor in a subperiosteal plane  has been advocated by certain authors and this technique is fol-  lowed in certain parts of the world. Again, there are conflicting  reports where the lingual flap retraction itself has caused an  increase incidence of lingual nerve paresthesia [8, 20-22].    The incidence of IAN involvement I—7 days after sur-  gery is around 1—5% and the incidence of lingual nerve  involvement one day after surgery (excluding the use of  lingual flap elevation) varies from 0.4 to 1.5% [23, 24].    Various techniques have been suggested for the preoperative  evaluation of difficulty, but these have often been of limited    (yellow arrow) at coronal level (b), at cervical level (c), and at apical  one third level (d)    value. Pederson [25] recommended a scale to evaluate the  difficulty index.   Although the Pederson scale can be used for predicting  operative difficulty, it is not extensively used [26] because it  does not take various other relevant factors into account, such  as bone density, flexibility of the cheek, and mouth opening.    Surgical removal impacted third molar becomes dif-  ficult with the following factors:-    1. Unfavorable root morphology- Excessive curvature,  divergent roots, hypercementosis, proximity to canal   6. Mouth opening—If the patient has a small com-  missure, or trismus, access becomes limited.   8. Width of the periodontal membrane—In patients past  middle age, the space containing it is much smaller  than in young patients. This makes removal difficult.   10. Local or systemic pathologic conditions.  11. Age of the patient.    Surgical removal of impacted teeth may be easier in  younger patients because of incompletely formed roots,  large follicular space, incompletely formed roots separated  from inferior alveolar canal, and greater elasticity of bone. In  young patients, the bone texture is usually soft and resilient,  but in older adults, the bone becomes progressively more  dense, hard, and brittle. Therefore, the extraction of a par-  tially erupted/impacted tooth in an elderly adult with scle-  rotic bone may cause great difficulty. While a tooth with  adverse root morphology in soft, resilient bone of a young  adult can be elevated expeditiously.    To summarize, the difficulty of the surgical procedure  is dictated by 3 major factors:- (1) Depth of impaction  (2) Type of overlying tissues, and (3) Age of the patient.    As a general rule, the more difficult and time-consuming  the surgical procedure is, the more difficult and protracted is  the postoperative recovery period.    1. Placement of an incision to access the region of the  impacted tooth.    Envelope flap, which is commonly used, extends from the  posterior margin of the impacted tooth, and runs forward till  the level of the first molar. The posterior end of the incision  is directed buccally along the external oblique ridge  (Fig. 14.21a, b).   If greater access is required, the envelope flap will not be  adequate. In such cases, a release incision is given on the  anterior-most point of the incision, which creates a triangular  flap (Fig. 14.22a, b). This incision must begin at a point that  lies approximately 6 mm below the gingival margin in the  buccal sulcus and then extend upward in an oblique fashion  to the gingival margin. The incision ends on the margin at a  point between posterior and middle thirds of the second  molar.   The envelope incision has been associated with fewer  complications, and healing occurs faster as compared to the  triangular flap. A small artery, the buccal artery, may some-  times be encountered while placing the releasing incision,  and mild bleeding can result if this is injured. If more expo-  sure is needed, the vertical release incision can be brought  forward, and placed between the second and first molar as  shown in the Fig. 14.23a, b.   The incision is then continued along the cervical line  of the second molar and reaches the middle of its poste-  rior border. The incision continues in a posterior and lat-  eral direction, along the anterior border of the ramus,  depending on the exposure required. It is essential that  this arm of the incision is oriented laterally, and not in a  straight line, because the mandible diverges laterally. If  the incision is extended straight, the knife may cause lin-  gual nerve damage. The lateral extension will also pre-  serve small vessels that emerge from retromolar fossa  (Fig. 14.24).    Fig. 14.22 (a, b) Standard triangular flap with a release incision in the anterior aspect    Fig. 14.23 (a, b) Where more exposure is needed, the vertical release of the triangular flap is placed between the second and first molar    The mucoperiosteal flap is then reflected laterally with a  periosteal elevator. An Austin’s retractor (third molar retrac-  tor) is used to hold the flap in position. The “Minnesota  retractor” may also be used to hold the flap. This retractor  must be placed just lateral to the external oblique ridge.  Stability is achieved by resting against the lateral surface of  the mandible. While holding the retractor, fingers must rest  at its distal end so that the retractor can be moved laterally  without blocking the vision of the operator.   The literature shows various flap designs with modifica-  tions for lower third molar impactions with each claiming its  own merits [27, 28]. However, for the majority of the cases,  the conventional flap designs will serve the purpose.    After flap reflection, the next step is bone removal from  around the impacted tooth. The amount of bone to be  removed will depend on the depth of impaction. This can be  done either by use of bur/rotary instruments or by chisel and  mallet or ultrasonic devices/peizo surgery [29, 30] or laser  devices [31]. The method used may depend on individual  preference. Sufficient amount of bone must be removed,  both to free the tooth from obstruction and to provide a point  of application for the elevator.   The buccal cortex plays an important role in maintaining  the strength of the mandible. Hence, the removal of buccal  bone should be minimized, in order to prevent weakening  and fracture of the mandible. The bone buccal to and distal to  the impacted tooth must be removed until the cervical line of  the tooth. Beyond this, bone removal must be done  judiciously, in such a way that the strength of mandible is not  affected, but, at the same time, the efficiency of surgery is  maintained. To achieve this, a deep vertical gutter is drilled  on the buccal side, and, if required on the distal side of the  tooth. This “guttering method” maintains the buccal plate  height, does not weaken the mandible, and at the same time,  creates adequate space around the tooth to permit its free  movement (Fig. 14.25).   The “Postage stamp” method of bone removal used in  transalveolar extractions can also be used to remove the  buccal bone, but this method may be more time-consum-  ing. The surgical removal of an impacted tooth is basically  a transalveolar extraction and all the basic principles, right  from the mucoperiosteal flap design to bone removal and  closure has to be followed religiously to achieve good  healing.   Bone can also be removed from the mesial aspect of the  impacted tooth using this method. In this region, bone  removal must be extremely conservative to avoid damage  to the distal aspect of the adjacent second molar. Extreme    care is taken while removing bone on the distolingual  aspect, and proper retraction must be used to prevent lin-  gual nerve damage from the bur. Due to the likelihood of  damage to the lingual nerve, bone must not be removed on  the lingual aspect. The commonly used burs for bone  removal are the #8 round bur and a #703 fissure bur,  although a wide variety may be used based on individual  preference.   After the tooth is exposed, a point of application is  created for the elevator. This allows the tooth to be dis-  placed using only moderate force. If the tooth is resistant,  further bone removal or tooth sectioning must be  considered.    Once bone removal is complete, tooth elevation can be  attempted. Undue force should not be used for this purpose.  Applying inappropriate amount of force, especially without  sufficient bone removal, can cause the tooth to fracture, or  can even cause fracture of the mandible. Because of the  above risk, the use of instruments with high mechanical effi-  ciency is contraindicated for third molar removal. These  instruments include dental extraction forceps and cross bar    elevators. Once the obstructing bone has been removed,  only a small amount of force alone is needed to deliver the  tooth. Elevators such as the Warwick James elevator (both  straight and curved types) and Coupland elevator, which  have lower mechanical efficiency, may be used for this  purpose.    If the tooth has been sufficiently exposed but is still resistant  to moderate force, tooth sectioning must be considered. The  tooth is sectioned into appropriate pieces for easy delivery  from the socket. Sectioning of the tooth not only avoids addi-  tional bone removal, but it also reduces operating time. Tooth  sectioning can be carried out using a bur, which is preferred,  or a chisel. In the standard technique, sectioning is carried  out using the bur at the neck of the tooth, which facilitates  crown removal first, followed by the roots in a single piece.  Alternatively, the tooth may be divided horizontally also.  Nevertheless, in cases of divergent roots, or where the path  of withdrawal is complex, the roots may have to be divided  and removed separately.   The manner of sectioning of crown and root must be  decided individually for each case and the standard tech-  nique need not be followed exactly (Fig. 14.26).    Although the principles of third molar removal remain fun-  damentally the same, the angulation of the tooth may dic-  tate certain modifications. Angulation dictates the site of  application of the elevator, as the path of withdrawal of the  third molar should be along the line of least resistance.  Therefore, the angulation, in terms of mesioangular, hori-  zontal, vertical, and distoangular impactions must be  considered.   The mesioangular impaction (Fig. 14.27a, b, c) (Video  14.1) is generally considered to be the least difficult to  remove. After elevating the mucoperiosteal flap and expo-  sure of the crown, the buccal guttering is carried out till the  mesial surface of impacted tooth, to a point below the cemen-  toenamel junction. This allows the tip of the elevator to be  introduced to engage beneath the cervical cementum on the  mesial side of the tooth. When the elevator is rotated, the  interdental bone is used as the fulcrum and the tooth rotates  distally. Thus the tooth, which had an initial mesial angula-  tion, now occupies a vertical position. When more force is  applied using the elevator, the tooth is delivered. In some  instances, although the tooth becomes vertical, further move-  ment is prevented by the distal bone. This obstruction may be  relieved by one of the following methods:    Fig. 14.26 Possible damage to inferior alveolar neurovascular bundle  if the bur is carried to the full width of the tooth inferiorly. Hence, bur  is used to cut only three-fourth width of the tooth and the rest of the  tooth is separated using a suitable instrument    (a) Using a bur, distal bone may be removed and the tooth  may be dislodged distally. Then the tooth is removed.  The distal half of the crown may be sectioned by slic-  ing from the buccal groove to a point just below the  cervical line on the distal side of the tooth. This slice  is removed, and then the remainder of the tooth is  delivered using a straight elevator placed on the mesial  aspect.   (c) The point of application of the elevator is changed  from mesial to the buccal side and a firm upward force  is exerted. A purchase point can be created with a bur  and the toot can be delivered using a Cryer’s elevator.    Sometimes, the mesioangular tooth may be entrapped  beneath the distal convexity of the crown of the second  molar. In such cases, the tooth may be divided at the cervical  region to separate the crown, which is then removed by  applying force beneath its inferior surface. The roots may  then be delivered by engaging at the bifurcation.   If the tooth roots are in close contact with the mandibular  canal, applying levering force can force the root apex down-  ward which may damage the neurovascular bundle. Crown  sectioning must be preferred in such cases, which will allow  the roots to be delivered upward away from the canal. This  would prevent damage to the canal.   The horizontally impacted (Fig. 14.28a, b, c, d) (Video  14.2) tooth may need more bone to be removed as compared  to mesioangular impaction. A deeply impacted tooth tends to  engage either the crown or root of the second molar. This  makes its removal difficult. Adequate bone is removed superi-  orly to expose the entire crown width, as well as the upper  third of the root. The point of application of elevator is pro-    Fig. 14.27 (a, b, c) (see text for details) Steps in the surgical removal of mesioangular impaction. (a) Bone removed up to cemento enamel junc-    tion using bur, (b) Sectioning of tooth, (c) Tooth delivery using elevator    cured below the mesiobuccal aspect of the impacted crown.  The tooth is then sectioned at the cervical region and the crown  is removed from the socket. The root is then brought forward  into the vacant space previously occupied by the crown and it  is then removed either in a single piece or after sectioning.   In cases where the impacted tooth is not locked beneath  the distal convexity of the crown of the second molar and  when an adequate amount of distal bone has been removed,  it is possible to turn the tooth into a vertical position by  application of force in the mesial aspect. This is similar to  the procedure already described for the removal of mesioan-  gular impactions. Use of further force with the elevator will  expel the tooth out of the socket or force can be applied on  the buccal side to remove the tooth.   Another method of removing horizontal impactions is to  split the tooth horizontally into two by sectioning via the    buccal groove into separate mesial and distal roots (tech-  nique shown in Fig. 14.29). The distal root with the attached  crown part is elevated out first followed by the deeply lying  mesial root and part of the crown. If there is difficulty in  elevating the deeply placed mesial root segment, it can be  again sectioned into two at the cervical region and the crown  and the root parts may be removed separately.   The vertical impaction (Fig. 14.29a, b, c) is one of the  more difficult ones to remove, especially if it is impacted  very deeply. The procedure for bone removal and the sec-  tioning is similar to that of a mesioangular impaction. Here  also the bone is removed first from the occlusal, buccal, and  distal aspect. The distal half of the crown is then sectioned  and removed, and the tooth is elevated by applying a small  straight elevator at the mesial aspect of the cervical line.  Alternatively, similar to mesioangular impactions, a pur-    Fig. 14.28 (a, b, c, d) Steps in the surgical removal of a horizontally  impacted mandibular third molar. (a) Bone removal to expose the width  of the crown and the upper third of the root, (b) Crown may be sec-  tioned into two as shown in the figure and elevated separately. Another  technique is to divide the tooth at cemento enamel junction and elevate  the crown as a single piece, (c) After removal of the crown, the distal    chase point can be made on the buccal side of the tooth, and  a Cryer’s elevator may be used to deliver the tooth.   The distoangular impaction (Fig. 14.30a, b, c) is considered  to be the most difficult tooth to remove. The goal of the tech-  nique for removal of these teeth is to create an adequate buccal  and distal trough (guttering) around the crown of the tooth to a  depth below the cervical line. This will permit to make a point  of application of elevator on the buccal aspect of the tooth.  Then, using the buccal cortical plate as the fulcrum, force is  applied to elevate the tooth out of the socket upward and dis-  tally. If some movement is obtained, the distal portion of the  crown or the complete crown can be sectioned in a horizontal  fashion from the roots and removed. It is preferable in this case  to section the tooth segments further as needed rather than to  remove more bone. It would be wise to remember the adage    root sectioned at the furcation is brought forward into the space occu-  pied by the crown, (d) Removal of the mesial root. (the technique  shown in Fig. 14.29 can also be used for horizontal imapctions where  the tooth is sectioned via the bifurcation and distal crown and root is  elevated out first, followed by the mesial crown and root)   In cases where tooth sectioning is required, the distal root  should be elevated first followed by the mesial root.    After tooth delivery, all bone debris and tissue must be  removed from the socket. This is best accomplished by irri-  gation with saline and mechanically debriding the socket  and the area under the flap with a cruet. A bone file or a large  bur is used to smooth any rough and sharp edges of the    Fig. 14.29 (a, b, c) Steps in the surgical removal of a vertically  impacted mandibular third molar. (a) Bone removal to expose the width  of the crown, (b) Distal half of the crown sectioned up to the furcation    bone. Any remaining dental follicle must be removed using  a mosquito hemostat, to prevent cyst formation. An artery  forceps may be used to remove fractured interdental septum  or large pieces of bone. The socket and the wound margins  (including under surface of mucoperiosteum) is irrigated  with saline or sterile water to remove bone and tooth debris.    Before attempting closure, bleeding from the socket is com-  pletely arrested. Further bleeding from the socket can be  controlled using bone wax, Surgicel, or Gelfoam. If there is  bleeding from the socket underneath a tight suture, blood  will accumulate in surrounding tissue spaces leading to buc-  cal or lingual hematoma or ecchymosis. The flap is then    and it is removed along with the root, (c) Mesial half of the tooth is  elevated by mesial application of force at the cervical line    replaced to its original position and the initial suture placed  just distal to the second molar. This suture reduces the pos-  sibility of the development of periodontal pocket distal to the  second molar. The needle is passed from the buccal to the  lingual side. Additional sutures are then placed as necessary.  The sutures should be just tight enough to hold the flap. Over  tightening should be avoided. The vertical component of the  incision is left unsutured since it will act as a wound toilet.   Following the procedure, oral and written postoperative  instructions given to patient and bystander ensure better  patient compliance.   The influence of lower third molar impactions on the peri-  odontal health of the adjacent second molar and the influence  of third molar removal on the periodontal attachment of the  second molar is a very contentious topic and multiple studies  have been done in this regard [32].    Fig. 14.30 (a, b, c) Steps in the surgical removal of a distoangularly  impacted mandibular third molar. (a) Bone removed to expose the full  crown of the tooth to a depth below the cervical line, (b) Crown sec-  tioned in a horizontal fashion from the roots and removed (some sur-    14.8.8 Other Methods for Removal/Partial  Removal of Impacted Lower Third  Molar    In addition to the standard surgical technique described  above, there may be occasions where other methods of surgi-  cal removal also have to be considered. This is because no  technique is suited to every case and it will be ideal to learn  the different methods and choose the suitable one depending  upon the case. Readers are advised to refer the concerned  publications to get more details.    geons prefer to remove only the distal portion of the crown of third  molar, so that a point of elevation is available distal to the second molar  tooth), (c) Roots are then delivered together or sectioned and delivered  independently with a Cryer’s elevator   Partial odontectomy/Coronectomy [15, 16, 39].  Removal of the tooth after orthodontic extrusion  [40, 41].    Surgical management of upper third molars in general is less  complicated compared to lower third molars. They cause less  discomfort, are more likely to erupt and are simpler to remove  unless unerupted and encased in bone. Removal of upper  third molars results in far less postoperative morbidity.   The commonest type of impaction in maxillary third  molar is vertical [42].   Classification of impacted maxillary third molars—The  system of classification of impacted upper wisdom tooth is  basically the same as that for mandibular third molar.  However, there are some additional parameters to be con-  sidered which will aid in preoperative assessment of the  case and guide in planning the surgery for a successful  outcome.    1. State of eruption.  (a) Fully erupted.  (b) Partially erupted.  (c) Unerupted:  — within the bone  — immediately beneath the soft tissues   (d) Laterally displaced with the crown facing the cheek,  horizontal, inverted, and transverse positions.   (e) Aberrant position sometimes associated with patho-  logical condition such as cyst.    tive depth of the impacted maxillary third molar, (Fig. 14.32).  Position A—Occlusal surface of the third molar is at the  same level as that of the second molar.   Position B—Occlusal surface of the third molar is located  between the occlusal plane and cervical line of the second  molar.   Position C—Occlusal surface of the third molar is at or  above the cervical line of the second molar.   (a) Sinus approximation (SA)—No bone or a thin parti-  tion of bone between the impacted maxillary third  molar and maxillary sinus.   (b) No sinus approximation (NSA)—2 mm or more bone  between the impacted maxillary third molar and  maxillary sinus.    Fig. 14.31 Classification of impacted maxillary third molar based on angulation    Fig. 14.32 Pell and Gregory classification based on relative depth of impacted maxillary third molar    5. Nature of roots. 14.9.2 Indications for the Removal  (a) Fused (conical). of Maxillary Third Molar  (b) Multiple—Favorable/Unfavorable.  1. Unrestorable dental caries.  2. Recurrent pericoronitis.  3. A tooth that has erupted in a buccoverted or distal direc-  tion, which cause cheek bite, or abnormal bite patterns.  4. Tooth involved in pathological process such as cyst.  . Overerupted and nonfunctional upper third molar.  6. Interference with the placement of prosthesis.   . Paranasal sinus view: useful to view pathologies associ-  ated with the tooth.    e Proximity to maxillary sinus (Fig. 14.34).  ¢ Proximity to maxillary tuberosity.    (a—d) Impacted third molars in a 75-year-old male. (a)  OPG showing impacted 28, 38, and 48 with multiple root stumps and  dental caries for 18. (b) Axial CBCT showing close relationship of 18    ¢ Buccal pad of fat.  e Pterygopalatine fossa.  e Infratemporal fossa.    The main difficulty here is that the coronoid process may  block access to this region, which may be overcome by limit-  ing the amount of mouth opening.   The procedure for maxillary third molar surgical removal  is almost the same as that of the mandibular third molar.   It starts from the mesial aspect of the first molar and extends  distally beyond the distobuccal aspect of the second molar  and is then continued into the tuberosity. In case of a deeply  impacted tooth if greater access is required, a triangular flap  may be raised by placing a release incision mesial to the sec-  ond molar.    and 28 to maxillary sinus, (c) Sagittal view showing sinus approxima-  tion of roots of 27 and 28, (d) Sagittal view showing close relationship  of 18 to sinus floor    The mucoperiosteum is then reflected using a Howarth’s  periosteal elevator, which may also be used to retract the  flap.   Bone removal is generally limited to the occlusal and the  buccal aspect of the tooth down to the cervical line to expose  the entire crown (Figs. and ). This is done  using bur. To create space for the elevator to be inserted,  more bone may be removed from the mesial part of the tooth,  at a point above the maximum bulge of the crown.   Unlike mandibular third molars, maxillary third molars  rarely need sectioning, as maxillary bone expands easily,  being thin and elastic. Instances where the bone is thicker,  sclerotic and less elastic as in old patients, tooth removal is  enabled by bone removal rather than tooth sectioning. Chisel  is contraindicated to section the tooth due to the danger of  displacement of the tooth into the maxillary antrum.   Maxillary third molar teeth must not be sectioned unless  absolutely necessary, as displacement of small fragments  into the sinus or infratemporal fossa may occur.    Fig. 14.34 Schematic diagram showing the relationship of impacted  maxillary third molar to the floor of the maxillary sinus   angled elevators are used, access may be easier. Angled ele-  vators which can be used for this purpose are the Warwick   access and vision and may also prevent accidental displace-  ment of the maxillary third molar into tissue space beyond  the tuberosity.   1. Due to the proximity of the maxillary sinus and the infra-  temporal fossa, pressure should not be exerted in the  superior direction during bone removal and delivery of  the tooth.    Fig. 14.35 (a—d) Steps in the surgical removal of a mesioangularly  impacted maxillary third molar. (a) Incision to raise a triangular flap,  (b) Mucoperiosteal flap reflected, (c) Overlying bone removed from    occlusal and buccal aspect up to the cervical line and elevation of tooth,    Fig. 14.36 (a) Bone removal achieved on the occlusal and the buccal aspect of tooth down to the cervical line to expose the entire crown, in a  disto angular maxillary third molar impaction (b) Delivery of the tooth using an elevator    2. Sufficient space is created between the height of contour  of the crown (i.e. above the maximum bulge of the tooth)  and surrounding bone so that the tip of the elevator can be  placed above the height of contour of the tooth. Then  pressure is exerted in a distobuccal direction.   3. Moderate pressure is then exerted distally, buccally and  occlusally (i.e. downward and outward) with the fore  finger placed posterior to maxillary tuberosity to detect  tuberosity fracture if it occurs.   4. In case an accidental opening into the sinus is suspected,  every effort should be made to ensure proper closure and  the patient is instructed appropriately to prevent the  development of an oro-antral fistula.    14.9.5 Complications That Occur During  Surgical Removal of Impacted Maxillary  Third Molar    1. Tooth displacement into maxillary sinus—This usually  occurs in cases of partially erupted maxillary third molars,  which have conical roots and are located close to the floor  of the sinus. The risk increases if the root apex is in con-  tact with the floor of the sinus, and the initial position of  the tooth is high.   If this complication occurs, the tooth may have to  be removed from the sinus in order to avoid infection.  Initially, a suction tip may be placed at the sinus open-  ing to retrieve the tooth. Alternately, saline irrigation  into the sinus may be followed by applying the suction  tip. If these methods do not work, it is best to stop    attempts and place the patient on antibiotics and nasal  decongestants. The tooth may be retrieved later  through Caldwell-Luc approach, and the oro-antral  fistula may then be closed. The tooth may also be  removed using endoscopic sinus surgery [43, 44].  Detailed sequential approach of dealing with root/  tooth displaced into the sinus is mentioned in the  Chap. 24 on Oro antral communication and fistula in  this text book.    can be inadvertently displaced into the buccal soft tissues  [45] or into the infratemporal fossa [46]. Usually, this  happens: (a) when the flap raised buccally is not adequate  for access, (b) there is insufficient visibility during the  procedure, (c) improper extraction technique, (d) disto-  lingual angulation of tooth, and (e) the crown of the third  molar is at a level above the root apices of the adjacent  molar tooth.   Dimitrakopoulos et al. [46] have discussed the various  methods to remove a maxillary third molar that has been  displaced into the infratemporal fossa.    Complications of removal of impacted tooth can happen  during the procedure and late after the procedure. Mild  post operative pain, swelling and trismus can be expected    inmost case and these three can be considered as a sequel    (a) The actual surgical procedure. 1. Pain  (b) Late after surgery. 2. Edema  3. Trismus  4. Haemorrhage  5. Infection  A. Complications that can occur during the Surgical 6. Alveolar osteitis (Dry socket)  Procedure: 7. Nerve Injury:  These can happen at various steps in the procedure, (a) Lingual nerve injury  including: (b) Inferior alveolar nerve injury  1. Placement of incision.    2. Removal of bone. 9. Hematoma  3. Sectioning of the tooth. 10. Pain during swallowing  4. Tooth elevation and delivery. 11. Pyrexia  1. Complications during incision: IE ORM o ayia ; ae ahs  (a) Bleeding from retromolar vessels. 13, Temporomandibular joint (TMJ) complications  (b) Bleeding from facial vessels. Is Fracture et mie . 7  (c) Damage to lingual nerve. 15. Periodontal pocket formation distal to second  2. Complications during bone removal: moles : ;  (a) Use of bur. 16. Aspiration/Swallowing of tooth  e Accidental burns.  e Laceration of soft tissues.  : sk SO ete te eo eevee The management of impacted third molars involves  ; S : several considerations, and several controversies also  e Injury to adjacent tooth. pa eer  Penance exist in this area. Some of these are as follows:  ae : 2 ‘ e Whether to remove Asymptomatic/Disease-free  e Necrosis of bone.  SARA tooth [4-6].  a ; ° Age of removal [47].  (b) Use of chisel :  ee e Flap designs [20-22].  e Splintering of bone. ; :  : e Technique of removal: bur/laser [31]/peizo surgery  e Fracture of mandible. 29, 30]  ¢ Displacement of tooth into lingual pouch. Sea  : : e Primary closure of socket/secondary closure of  e Injury to lingual nerve.  : : socket [48].  e Injury to the soft tissues or second molar. ees See  es af ones ere ees omuenioen e Drains in socket/No drains in socket [49].  Deeg Gr al oS ak Sates ee ig * Whether to graft the Socket with PRP [50]/PRF  During bur usage [51-53]  ° pecioune gous puso le: e Reconstruction of distal periodontal defect of the  e Injury to mandibular canal. eecond molar [541  ¢ Breakage of bur. ,  4. Complications during elevation of tooth:   e Displacement of the entire tooth or crown alone  into the lingual pouch or lateral pharyngeal  space.    At present, the various evidence-based guidelines  available should help the clinician in taking informed  decisions regarding third molar impactions [55-57].  Efforts have been made to reach a consensus in various  areas, which itself shows conflicting propositions, and  only time will prove the best methods which can be used  in the management of third molar impactions.    . Archer WH. Oral and maxillofacial surgery, vol. I. 5th ed.    . Andreasen J.O, Petersen J.K, Laskin D.M. Textbook and color atlas    wisdom tooth: removal versus retention. Atlas Oral Maxillofac  Surg Clin North Am. 2012 Sep;20(2):169-76.    . Pogrel MA, Renaut A, Schmidt B, et al. The relationship of the lin-    gual nerve to the mandibular third molar region: an anatomic study.  J Oral Maxillofac Surg. 1995;53:1178-81.    . Behnia H, Kheradvar A, Shahrokhi M. An anatomic study of the    lingual nerve in the third molar region. J Oral Maxillofac Surg.  2000;58:649-5 1.   Winter GB. Principles of exodontia as applied to the impacted third  molar. St Louis: American Medical Books; 1926.   Pell GJ, Gregory BT. Impacted mandibular third molars: clas-  sification and modified techniques for removal. Dent Digest.  1933;39:330-8.   Suvy Manuel, Surej Kumar LK, Mathew P Varghese. A comprehen-  sive proforma for evaluation of mandibular third molar impactions.  J Maxillofac Oral Surg. 2014 Dec; 13(4):378-385.   Howe G, Poynton HG. Prevention of damage to the inferior alveo-  lar nerve during the evaluation of mandibular third molars. Br Dent  J. 1960;109:355-63.   Rood JP, Shehab BA. The radiological prediction of inferior alveo-  lar nerve injury during third molar surgery. Br J Oral Maxillofac  Surg. 1990 Feb;28(1):20-5.   Pogrel MA, Lee JS, Muff DF. Coronectomy: a technique to protect  the inferior alveolar nerve. J Oral Maxillofac Surg. 2004;62:1447.  Renton T, Hankins M, Sproate C, McGurk M. A randomised  controlled clinical trial to compare the incidence of injury to the  inferior alveolar nerve as a result of coronectomy and removal of  mandibular third molars. Br J Oral Maxillofac Surg. 2005;43:7.  Tantanapornkul W, Okouchi K, Fujiwara Y, et al. A compara-  tive study of cone-beam computed tomography and conventional  panoramic radiography in assessing the topographic relationship  between the mandibular canal and impacted third molars. Oral Surg  Oral Med Oral Pathol Oral Radiol Endod. 2007;103:253.   Ohman A, Kivijarvi K, Blomback U, Flygare L. Pre-operative  radiographic evaluation of lower third molars with computed  tomography. Dentomaxillofac Radiol. 2006;35:30.   Danforth RA, Peck J, Hall P. Cone beam volume tomography: an  imaging option for diagnosis of complex mandibular third molar  anatomical relationships. JCDA. 2003;31(11):847-S2.  Gargallo-Albiol J, Buenechea-Imaz R, Gay-Escoda C. Lingual  nerve protection during surgical removal of lower third molars. J  Oral Maxillofac Surg. 2000;29:268.   Pichler JW, Beirne OR. Lingual flap retraction and prevention of  lingual nerve damage associated with third molar surgery: a sys-  tematic review of the literature. Oral Surg Oral Med Oral Pathol  Oral Radiol Endod. 2001;91:395.   Pogrel MA, K.E. Goldman: lingual flap retraction for third molar  removal. J Oral Maxillofac Surg. 2004;62:1125.    Gulicher D, Gerlach KL. Sensory impairment of the lingual and  inferior alveolar nerves following removal of impacted mandibular  third molars. Int J Oral Maxillofac Surg. 2001;30:306.    alveolar nerve damage after lower third molar surgical extraction: a  prospective study of 1117 surgical extractions. Oral Surg Oral Med  Oral Pathol Oral Radiol Endod. 2001;92:377.   Pederson GW. Oral surgery. Philadelphia: WB Saunders; 1988.  (Cited in: Koerner KR. The removal of impacted third molars—  principles and procedures. Dent Clin North Am. 1994; 38:255-78)  Yuasa H, Kawai T, Sugiura M. Classification of surgical difficulty  in extracting impacted third molars. Br J Oral Maxillofac Surg.  2002 Feb;40(1):26-31.   Erdogan O, Tath U, Ustiin Y, Damlar I. Influence of two different  flap designs on the sequelae of mandibular third molar surgery. Oral  Maxillofac Surg. 2011 Sep;15(3):147-52.   Goldsmith SM, De Silva RK, Tong DC, Love RM. Influence of a  pedicle flap design on acute postoperative sequelae after lower third  molar removal. Int J Oral Maxillofac Surg. 2012 Mar;41(3):371-S.  Rullo R, Addabbo F, Papaccio G, D'Aquino R, Festa  VM. Piezoelectric device vs. conventional rotative instruments  in impacted third molar surgery: relationships between surgical  difficulty and postoperative pain with histological evaluations. J  Craniomaxillofac Surg. 2013 Mar;41(2):e33-8.   Piersanti L, Dilorenzo M, Monaco G, Marchetti C. Piezosurgery or  conventional rotatory instruments for inferior third molar extrac-  tions? J Oral Maxillofac Surg. 2014 Sep;72(9):1647-52.   Stiibinger S, von Rechenberg vB, Zeilhofer HF, Sader R, Landes  C. Er: YAG laser osteotomy for removal of impacted teeth: clini-  cal comparison of two techniques. Lasers Surg Med. 2007  Aug;39(7):583-8.   Krausz A, Machtei E, Peled M. Effects of lower third molar extrac-  tion on attachment level and alveolar bone height on the adjacent  second molar. Int J Oral Maxillofac Surg. 2005;34:756.   Amin M, Haria S, Bounds G. Surgical access to an impacted lower  third molar by sagittal splitting of the mandible: a case report. Dent  Update. 1995;22:206-8.   Tay Andrew BG. Buccal corticotomy for removal of deeply impacted  mandibular molars. Br J Oral Maxillofac Surg. 2007;45:83-4.   Ward TG. The split bone technique for removal of lower third  molars. Br Dent J. 1956;101:297.   Farish SE, Bouloux GF. General technique of third molar removal.  Oral Maxillofacial Surg Clin N Am. 2007;19:23-43.   Henry CB. Excision of the developing mandibular third molar by  lateral trepanation. Br Dent J. 1969;127:111-8.   Chiapasco M, Crescentini M, Romanoni G. Germectomy or  delayed removal of mandibular impacted third molars: the relation-  ship between age and incidence of complications. J Oral Maxillofac  Surg. 1995;53(4):418-22.   Pogrel MA. Partial odontectomy. Oral Maxillofacial Surg Clin N  Am. 2007;19:85-91.   Checchi I, Alessandri Bonetti G, Pelliccioni GA. Removing high  risk impacted mandibular third molars: a surgical-orthodontic  approach. J Am Dent Assoc. 1996;127:1214.   Alessandri Bonetti G, Bendandi M, Checchi V, Checchi  I. Orthodontic extraction: riskless extraction of impacted lower  third molars close to the mandibular canal. J Oral Maxillofac Surg.  2007;65(12):2580-6.   Peterson LJ, Ellis E, Hupp JR, Tucker MR. Contemporary oral and  maxillofacial surgery. 4th ed. St. Louis: Mosby; 2003. p. 185-237.  Bouloux Gary F, Steed Martin B, Perciaccante VJ. Complications  of third molar surgery. Oral Maxillofacial Surg Clin N Am.  2007;19:117-28.   Pogrel M. Complications of third molar surgery. Oral Maxillofac  Surg Clin North Am. 1990;2:441.    Matthew I. What should I do if a maxillary third molar is inad-  vertently displaced into the adjacent soft tissues during surgical  removal? [point of care]. J Can Dent Assoc. 2007;73(4):31 1-2.  Dimitrakopoulos I, Papadaki M. Displacement of a maxillary third  molar into the infratemporal fossa: case report. Quintessence Int.  2007;38(7):607—10.   Haug RH, Perrott DH, Gonzalez ML, Talwar RM. The American  association of oral and maxillofacial surgeons age-related third  molar study. J Oral Maxillofac Surg. 2005;63(8):1106-14.  Pasqualini D, Cocero N, Castella A, Mela L, Bracco P. Primary and  secondary closure of the surgical wound after removal of impacted  mandibular third molars: a comparative study. 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Efficacy  of platelet-rich fibrin after mandibular third molar extraction: a  systematic review and meta-analysis. J Oral Maxillofac Surg. 2017  Jun;75(6):1124-35.   Dodson T. Is there a role for reconstructive techniques to prevent  periodontal defects after third molar surgery. J Oral Maxillofac  Surg. 2005;63:891.   Task Force for Third Molar Summary. Summary of the third molar  clinical trials: report of the AAOMS task force for third molar sum-  mary. J Oral Maxillofac Surg. 2012 Sep;70(9):2238-48.  https://www.nice.org.uk/guidance/tal  https://www.aaoms.org/docs/govt_affairs/advocacy_white_papers/  white_paper_third_molar_data.pdf    Open Access This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.  org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropri-  ate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.   The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in  a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.    Impacted canines are one of the common problems encoun-  tered by the oral surgeon. Patients may present at different  ages and many cases will be incidental findings. Close inter-  action with the paedodontist and orthodontist is required to  get an optimal out come. Surgical removal may not be the  best treatment in all the cases and particular treatement plan  will have to be tailored for the needs of the patient. Localising  the impacted canine seems not a challenge any more with the  advent of CBCT, in indicated cases. This chapter elaborates  on canine impaction, keeping in mind the basic principles  mentioned in the chapter on third molar impactions.  Premolars, incisors and other teeth may be impacted but  most of the surgical principles and approaches mentioned for  canine can be applied to them as well.   Maxillary canine is the second most commonly impacted  tooth, after the mandibular third molar. The permanent max-  illary canine may be considered as impacted when the erup-  tion of the tooth lags behind as compared to the eruption  sequences of other teeth in the dentition. Diagnosis of maxil-  lary canine impaction may be made by clinical examination  and by radiography.   The normal path through which maxillary canines erupt  may be altered due to changes in the eruption sequence in the  maxilla, and also by space limitations due to crowding. It is  essential to diagnose and treat this condition early, to prevent    Electronic Supplementary Material The online version of this chapter  (https://doi.org/10.1007/978-98 1-15-1346-6_15) contains supplemen-  tary material, which is available to authorized users.   Principal, Professor and Head, Department of Oral and  Maxillofacial Surgery, Pushpagiri College of Dental Sciences,  Tiruvalla, Kerala, India    © The Association of Oral and Maxillofacial Surgeons of India 2021    the development of complications. An ideal management  protocol for impacted permanent maxillary canines should  involve an interdisciplinary approach linking the specialties  of oral and maxillofacial surgery, periodontology and  orthodontics.    Although the exact cause of impacted maxillary canines  remains unknown, multiple factors may play a role. Primary  causes that have been linked to impacted maxillary canines  include the rate at which roots resorb in the deciduous teeth,  any trauma to the deciduous tooth bud, disruption of the nor-  mal eruption sequence, lack of space, rotation of tooth buds,  premature root closure and canine eruption into a cleft.  Secondary reasons include febrile diseases, endocrine  disturbances and Vitamin D deficiency. Impacted canine can  be concomitant with other conditions.   Except the third molars, maxillary canines are among the  last teeth to erupt. They usually develop high in the maxilla  and need to travel a considerable distance before they erupt.    Local factors may also play a role in canine impaction,  and these include:    1. A longer eruption path that the tooth has to traverse  from its point of development to normal occlusion  [ae   2. Thick palatal bone and mucoperiosteum, which can  obstruct eruption of palatally oriented canines.   3. More developed root at the time of eruption, which  may minimize the eruptive force.   4. Disorder of the primary canine can affect the posi-  tion of the permanent one. This is because the  crown of the developing permanent canine lies just  palatal to the apex of the primary canine root.    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1-15-1346-6_15    5. Canines are more susceptible to environmental  influences as they are among the last teeth to erupt  (except the third molars).   6. Limited space for eruption as the canines erupt  between teeth which are already in occlusion. The  second molar may further reduce the space.   7. The permanent canine has a greater mesiodistal  width than the primary canine.    15.3.1 The Following Classification Suggested  by Archer (1975) [2] is Very Practical    Class I: Impacted canines in the palate.  1. Horizontal  2. Vertical  3. Semivertical   ¢ Class II: Impacted canines located on the labial surface.  1. Horizontal  2. Vertical  3. Semivertical   ¢ Class III: Impacted canine located labially and pala-  tally—crown on one side and the root on the other side.   ¢ Class V: Impacted canine in edentulous maxilla—  Impacted canine can be in unusual positions like inverted  position.    Maxillary Canines  1. Labial position  ¢ Crown in intimate relation with incisors.  ¢ Crown well above apices of incisors.  2. Palatal position  ¢ Crown near surface.  ¢ Crown deeply embedded in close relation to apices of  incisors.  3. Intermediate position  ¢ Crown between lateral incisor and first premolar roots.  ¢ Crown above these teeth with crown labially placed  and root palatally placed or vice versa.  4. Unusual position  ¢ In nasal or antral wall.  ¢ In infraorbital region.    1. Adjacent teeth may undergo internal or external  resorption.  2. Change in alignment or proclination of lateral inci-  sor (Fig. 15.1).  . Odontogenic Cyst formation.  4. Development of Odontogenic Tumour.    1. Prolonged retention of the primary canine [4] and  or delayed eruption of the permanent canine.   2. Lack of a bulge on the labial side of the alveolus in  the canine region.   3. Delayed eruption of the lateral incisor, or an incisor  that is tipped distally or migrated.   4. Loss of vitality or increased mobility of the perma-  nent incisors.    The position of the impacted canine may be determined by  visual inspection, palpating intraorally or by radiography.  Radiographic examinations may include periapical X-ray  with cone shift technique, occlusal radiography, anteroposterior  and lateral radiographic views of maxilla, OPG, CBCT, CT scan.    ¢ Labiopalatal position of the canine relative to the erupted  teeth—either labial, palatal or directly above the teeth.   ¢ Orientation of the long axis of the canine in relation to the  adjacent teeth.   ¢ Size and shape of the canine, and its root pattern.    Fig. 15.1 Bilaterally impacted maxillary canine causing proclination and spacing of incisors. (a) Frontal view, (b) Occlusal view, (¢) OPG    ¢ Location and orientation of the crown and root in relation  to the adjacent teeth, in three dimensions (vertical, mesio-  distal and labiopalatal).    Going into the fine details of localization of canine is  beyond the purview of this chapter. It is an area which has  been extensively studied with regard to the various imaging  modalities and their advantages.   Various radiographic methods are considered routinely by  practitioners for localization. A few of them are mentioned  below.   This was first introduced by Clark [5], and involves two  radiographs taken at two different horizontal angles, but  using the same vertical angulation. Owing to parallax error,  the object that is further away appears to travel in the same  direction as the direction in which the tube was shifted. The  object nearer to the tube appears to move in the opposite  direction [Same Lingual Opposite Buccal (SLOB) rule].    This technique can also be performed with differing vertical  angulations (vertical parallax). There are different combina-  tions of parallax techniques:    1. Clark technique: Two intra-oral periapical radiographs  are taken using different horizontal angulations [5].   2. Southall and Gravely technique: One maxillary anterior  occlusal radiograph and one maxillary lateral occlusal  radiograph are taken [6].   3. Rayne technique: This involves differing vertical angula-  tions, with one periapical and one maxillary anterior  occlusal radiograph being taken [7].   4. Keur technique: This is also a vertical parallax method, in  which one panoramic and one maxillary anterior occlusal  radiograph are taken [8].   1. Magnification  The magnification technique depends on a principle  known as ‘image size distortion’. According to this, for a  given ‘focal spot’—film distance, objects that are far  away from the film will appear more magnified than those  that are closer to the film. This has been applied using    OPGs for the impacted canine. (Wolf and Matilla [9]; Fox  et al. [10]). In the OPG, if a canine looks bigger as com-  pared to the adjacent teeth in the arch or the contralateral  canine, it is probably located closer to the tube (palatal).  If it is relatively small, it is located further away from the  tube (labial). This method can be applied effectively only  when the canine is not rotated, does not touch the incisor  root and the incisor is not tipped [11].   Kuftinec [12, 13] asserts that if the canine’s cusp is  mesially at the root of the lateral incisor, the impaction  is probably palatal but if the cuspid is found overlap-  ping the distal half, a labial impaction is more  probable.   2. Chaushu et al. [14] stated that a single panoramic radio-  graph could be used to assess the mesiodistal dimensions  of the canine and the ipsilateral central incisors. The  canine would be palatally placed if the ratio of the sizes  between the canine and the central incisors is 1.15 or  greater.   3. Katsnelson [15] et al. suggested a technique that used  a horizontal line that extended from the mesiobuccal  cusp tip of the right and left maxillary first molars,  along the long axis of the impacted canines. The degree  of inclination of the canine as compared to the midline  is recorded. If the inclination is greater than 65°, the  canine is 26.6 times more likely to be buccally placed  than palatal.   Computed Tomography readily provides excellent tissue  contrast and eliminates blurring and overlapping of adjacent  teeth [16]. However, since CT exposes the patient to a high  dose of radiation, the unfavourable relationship between cost  and benefit to the patient determines its use only in particular  cases, such as in the presence of craniofacial deformities. CT  makes it possible to easily identify the position of impacted  teeth and evaluate precisely the location of nearby anatomi-  cal structures and identify any root resorption in the adjacent  teeth.   Conventional CT imaging is associated with high radiation  dose and high cost. Cone Beam Computed Tomography  (CBCT) have been used instead for localization of the  impacted canine. As CBCT uses cone-shaped radiation, the  radiation dose is significantly reduced, and a high spatial  resolution is achieved [17, 18].    The impacted maxillary canine may be managed by several  different techniques. The chosen method would depend on the  degree of impaction, age of the patient, stage of root forma-  tion, presence of any associated pathology, dental condition of  the adjacent teeth, position of the tooth, patient’s willingness  to undergo orthodontic treatment, available facilities for spe-  cialized treatment and patient’s general physical condition.    1. Extraction of primary canine.  This method is as an interceptive form of management.  Extraction of the deciduous tooth may be considered when  the maxillary permanent canine is not palpable in its nor-  mal position and the radiographic examination confirms  the presence of an impacted canine. However, this treat-  ment will not necessarily correct the problem. Surgical  intervention may be required if the permanent canine fails  to erupt within one year of the deciduous extraction.   2. No treatment—Leave the tooth in situ.  In some asymptomatic cases, no treatment may be required  apart from regular clinical and radiographic follow-up.  There is a small risk of follicular cystic degeneration,  although the incidence of this is unknown. Rarely, odonto-  genic tumours may develop in relation to the impacted tooth.    3. Surgical exposure of the tooth.  This technique may be used in cases where there is    enough space for the canine to erupt, and where the root   (b) The patient must be compliant with both surgery and  long term orthodontics.    This technique is preferred for teeth that are in an unfa-  vourable position, and which are likely to cause problems  in the future. It may also be considered when a patient is  not willing for orthodontic treatment or cannot afford it,  even if the impacted tooth is in a favourable position.  Surgical repositioning/Autotransplantation.   Impacted canines that are malpositioned, but have a  favourable root pattern (without hooks or sharp curves)  may be considered for autotransplantation into the dental  arch. This may be done by utilizing the socket of decidu-  ous canine or first premolar, depending on the amount of  space needed and available.    The location of the crown of the impacted canine may be  determined by radiographs. The possible position of the  crown is determined, and a cruciform incision made over  this. Along the incision arms, flaps are elevated on four sides  so that the crown is uncovered. The flaps may be excised. If  there is haemorrhage, it can usually be controlled by pressure  application. If there is any bone overlying the crown, it is  removed and sharp edges are smoothened so that the crown  lies in a saucer-shaped bony cavity. To prevent soft tissue  regrowth over the exposed crown, a pack (such as a perio  pack or roller gauze impregnated with iodoform or antibiot-  ics) may be inserted or sutured in place. Another alternative  technique is to use a crevicular incision, expose palatally and  place orthodontic brackets as shown in Fig. 15.2.   (a) Creating a surgical window/Gingivectomy: This is  done if the tooth lies just underneath the gingiva. The  overlying soft tissue is simply excised to expose the  crown.   If the impacted canine is close to the alveolar crest,  or if a broad band of keratinized tissue covers the  tooth, a surgical window may be created. Gingivectomy  may be done when it is possible to uncover at least one    exposure techniques in the periodontium; however, a consen-  sus is yet to be reached [22-24].   Chapokas et al. in 2012 have brought out a useful classifi-  cation of maxillary canine impactions based on which the  exposure technique may be decided [25].    half to 2/3 of the crown, leaving at least 3 mm of gin-  gival collar. Usually in these cases, the tip of the  impacted tooth lies near the cemento-enamel junction  of the adjacent tooth (Fig. 15.3).   Closed eruption technique: If the impacted canine  lies in the middle of the alveolus, near the nasal spine,  or high in the buccal vestibule or the palate, this tech-  nique may be indicated (Vermette et al., 1995) [19].  A flap is first elevated over the area of the impacted  tooth. If necessary, the crown is then exposed after  removal of the overlying bone. An orthodontic  bracket may be bonded to the crown and to the  bracket, a traction wire is affixed. The flap is then  sutured, with the traction wire left exposed to the oral  cavity. Sufficient time is given for the flap to undergo  initial healing. Later on, the traction wire may be  connected to an archwire and optimal force may be    applied as needed for the tooth to erupt. Drawback of  this technique is that the tooth cannot be inspected  directly once the flap has been sutured (Fig. 15.4).    portion of the crown does not lie within the attached  gingiva, removal of the soft tissue may cause the  attached gingiva to be lost. Later on, this can lead to  periodontal problems. In such a case, it may be better  to use an apically repositioned flap.   The flap is designed in such a way that vertical  incisions are placed on the soft tissue at the distal  side of the lateral incisor and at the mesial side of the  first premolar. Then a horizontal incision is made that  links the two vertical incisions. Subsequently, after  locating the crown of the impacted tooth, the flap  may be sutured back into at the apical end, while the  crown is exposed to the oral cavity (Fig. 15.5a, b).    Fig. 15.5 (a, b) Schematic diagram of apically positioned flap for exposure of a labially positioned crown. (a) Incision, (b) Suturing    If the impacted maxillary canine is in an unfavourable posi-  tion, and cannot be brought into normal occlusion, it should  be removed earlier rather than later. This is because increas-  ing age increases the difficulty of the procedure, and by  removing early, damage to the adjacent structures may be  minimized.   The impacted canine is separated by a thin layer of the bone  from the maxillary sinus and nasal cavity (Fig. 15.6).  Infrequently, this bone may be absent. In these cases, the risk  of tooth or root displacement into the maxillary sinus is high.  It is also not uncommon to have the likelihood of creating a  communication between the oral cavity and antrum, which  may lead to post-operative nasal bleeding.    Fig. 15.6 Surgical anatomy  of maxillary canine area. Note  the close relationship of the  root of the impacted canine to  the floor of the maxillary  sinus and nose   The incision is initiated in the gingival margin on the palatal  side from the ipsilateral first premolar and, depending on the  position of the impacted tooth, is extended up to the contra-  lateral lateral incisor or premolar.   In cases of unilateral impaction, instead of extending the  incision to the contralateral side, a vertical incision may be  given in the mid palatal region. In situations where there is  bilateral canine impaction and both teeth are close to the  midline, the incision should always extend between the first  or second premolars of both sides (Fig. 15.8). Elevation of a  single palatal flap not only avoids sloughing but also pro-  vides adequate visualization. This method may pose a risk of  haemorrhage from the nasopalatine vessels which can, how-  ever, be controlled by pressure pack or by electrocautery.   The mucoperiosteal flap is then reflected to reveal the  palatal bone and the tooth. Division of the nasopalatine ves-  sels and nerve may be done for further exposure.    Fig. 15.7 (a—d) Schematic  diagram showing steps in the  surgical removal of palatally  positioned impacted maxillary  canine (a) Reflection of the flap,  (b) Removal of bone to expose  the crown, (c) Sectioning of the  crown, (d) Removal of the root    Fig. 15.8 (a, b) Palatal flap  elevation for exposure of  bilaterally impacted palatally  positioned canine. (a) Flap  outlined from the second  premolar on one side to the  second premolar of the opposite  side, (b) Following reflection of  the mucoperiosteal flap, multiple  drill holes are placed in the bone  overlying the crown. These drill  holes are then connected together  to remove the bone thereby  exposing the crown    Fig. 15.9 (a, b) Incisions for removal of labially placed canine. (a) Semilunar incision, (b) Trapezoidal (3 sided) incision    The crown of the tooth may be visible occasionally, or  a bulge may be felt. Bone around the area is removed with  bur, taking care to protect the roots of the adjacent teeth  from damage. Once adequate bone is removed, a groove is  prepared on the mesial side and an elevator may be  inserted into it. An attempt is made to luxate the tooth.  Once the crown is moved out, it may be grasped using an  upper anterior or premolar forceps. Dislodgement of the  root apex may require a certain amount of torsion, as this  is often curved.   If the tooth is resistant to elevation, more bone removal  is done to enlarge the opening. Tooth sectioning (odontot-  omy) may be carried out using a straight fissure bur if there  is any obstruction to movement (Fig. 15.7c, d). The crown  portion is removed first. A portion of the root may then be  visualized. If not, bone is removed to expose the root. A  hole is created in the root and an elevator is used to engage  this and remove the root.   Meticulous debridement and curettage is done to  remove the tooth follicle. Saline irrigation is used to clear  out bone debris. The flap is replaced and sutured into  position. It is held in close contact with the palatal bone  by pressing a gauze pack with the dorsum of the tongue,  for an hour or two. Healing follows without any  complications.   To decrease chances of hematoma formation, a prefabri-  cated clear acrylic plate may be used to cover the palate  post-operatively.    15.5.3 Surgical Removal of Labially Positioned  Impacted Maxillary Canine (Fig. 15.9a, b)  (Video 15.1)    15.5.3.1 Incision  A semilunar incision (Fig. 15.9a) is usually used, and it pro-  vides good exposure. The lower part of the incision must lie  at least 0.5 cm away from the gingival margin.   For cases that are deeply impacted, triangular flaps (2 sided)  or trapezoidal flaps (3 sided) may be used, with incisions  along the gingival margin and relieving incisions. (Fig. 15.9b).   (Fig. 15.1 1a-i)  The mucoperiosteal flap is elevated and the bone with the tooth  bulge is exposed. Using a bur, a window is created over the crown  prominence. The window is enlarged so that the entire crown is  exposed, taking care not to cause damage to the adjacent tooth  roots. The tooth is then luxated using an elevator.   If there is any resistance during elevation, the tooth must  be sectioned, so that the fragments can be removed easily. If  three fragments are created, the middle one may be removed  first, and the remaining two fragments may be elevate using  the resultant space (Fig. 15.10a—f).   The area is carefully debrided and checked for a residual  follicle, which must be removed. The mucoperiosteal flap is  repositioned and sutured (Fig. 15.1 1a—i) shows the localisa-  tion and surgical removal of a labially positioned impacted  maxillary canine.    Fig. 15.10 (a—f): Schematic diagram  showing surgical removal of labially  impacted maxillary canine. (a) Impacted  maxillary canine. Note the relationship of  the cuspid to the roots of the adjacent teeth,  nasal cavity and maxillary sinus. (b)  trapezoidal mucoperiosteal flap reflected.  (c) Drill holes placed in the cortical plate  overlying the crown so as to expose the  crown, after the full exposure of the crown,  elevator is applied beneath the crown to  mobilize the tooth, (d) If the tooth is  resistant to elevation, the crown is sectioned  using bur and it is removed, (e) Cavity  created following removal of crown, (f) The  root is moved into the space created by the  removal of the crown and it is then removed    The impacted maxillary canine may be located in an inter-  mediate position, with the root oriented labially and the  crown palatally, or vice versa. Removing a maxillary canine  in the intermediate position may be challenging and may  take more time as it may require a labial and palatal  approach. The risk of damaging adjacent teeth is also  higher with teeth in an intermediate position. CBCT or CT  scan is very useful to locate the exact position of such a  tooth. Figure 15.12a—h illustrates the steps involved in    removing an impacted canine that has its root oriented labi-  ally and crown palatally.   e Fracture of apical third of the root of the impacted  tooth.    Fig. 15.11 (a-l) show the clinical and radiographic images of the steps  in removing a labially impacted canine by odontectomy. Bilaterally  impacted maxillary canines (a) Intra-oral right lateral view, (b) OPG  showing 13 in inverted position (yellow circle) with close proximity to  maxillary sinus and impacted 23 (in red circle). CT of the same patient  showing the relationship of the inverted 13 (yellow circle) to adjacent    structures such as maxillary antrum, nasal floor and nearby teeth. (c)  Sagittal view, (d) Coronal view, (e) Axial view, (f) 3-D view. Steps in  the surgical removal of impacted 13. (g) Incision marked, (h)  Mucoperiosteal flap reflected, (i) Tooth division done, (j) Tooth  removed and debridement (k) Suturing completed, (1) Specimen    Impacted mandibular canines are not as frequent as maxil-  lary canines, and are usually found in a labial position.  However, they may occasionally migrate to the mental  protuberance or even the lower border of mandible, where  they can lie in a transverse position. They can also drift to  the opposite side of the mandible, referred to as transposi-  tion/transmigration of the canine. It must be noted that    these teeth retain their original innervation, which is  important to consider while administering local  anaesthesia.   The diagnosis of an impacted mandibular canine is simi-  lar to that of the impacted maxillary canine, and it presents  with similar features. These include retained primary teeth,  proclination/displacement of adjacent incisors or clinical  features associated with cyst formation. Impacted canines  may not be associated with any symptoms, and may be acci-  dentally discovered during the routine radiographic exami-    Fig. 15.12 (a—h) Schematic  diagram showing the steps in the  surgical removal of impacted  maxillary canine with root on the  labial side and crown on the  palatal side. (a) Outline of the  impacted canine and its relation  to the roots of the adjacent tooth.  Note the semilunar incision  marked, (b) Outline of the crown  of the impacted canine on the  palatal aspect, (c)  Mucoperiosteum reflected on the  buccal side overlying the bone to  be removed and the root of the  impacted tooth sectioned. An  elevator is being used to dislodge  the root, (d) Empty socket after  removal of the root. (e) Palatal  flap is outlined and reflected.  Bone covering the crown of the  impacted tooth is removed using  bur. (f) Using a blunt instrument  placed in the socket of the tooth  on the buccal side, pressure is  exerted on the cut end of the  crown (see black arrow) to push  the crown palatally, (g) Empty  socket on the palatal side after  removal of the crown, (h) Flap is  replaced back and suturing  completed    nation, or during the investigation of other dental conditions.  Sometimes, however, these teeth can cause recurrent pain  and infection.   Dalessandri et al. in 2017 opined that the most common  treatment strategies for the treatment of mandibular canine  impactions are surgical extraction and orthodontic traction.  Surgical extraction and radiographic monitoring were sug-  gested for transmigrant mandibular canines: The authors pro-  posed a decision tree in order to guide practitioners through  the treatment plan of impacted mandibular canines [26].    15.5.5.1 Treatment Options  The impacted mandibular canine may be treated using one of  the following strategies:   (a) Pathology such as follicular cyst or tumour in rela-  tion to the impacted tooth.   (b) Orthodontic reasons, such as the need to move an  adjacent tooth into the area of impaction.   The bone in the mandibular canine region consists of a thick  lingual cortex and a thin buccal cortex. The impacted tooth  usually lies mesial or distal to the actual canine region. A  buccal flap must ideally be used for surgical access, as a lin-  gual flap may not provide adequate access, and is associated  with increased post-operative morbidity. While raising the  buccal flap, the mentalis muscle insertion (at the mental  fossa) and incisive muscle insertion (at the height of the  canine alveolus) are divided.   For tooth exposure, a trapezoidal (3 sided) flap is used.  Alternately, a horizontal incision may be made below the  attached gingiva. If the tooth lies close to the lower bor-  der of the mandible, an additional incision may be needed  extra-orally for proper exposure. As in the case of maxil-  lary canine in the labial position, bone removal is done  with bur. The tooth may be elevated in toto, or may  require sectioning if resistance is met (Figs. 15.14a—h  and 15.15).    1. Injury/mobility of the adjacent tooth—This can occur  during bone removal, if the supporting bone of the lateral  incisor is removed accidentally. This is managed by  splinting the lateral incisor to the adjacent tooth.   2. Mental nerve injury—If the distal vertical incision is  extended too far backwards and inferiorly, the mental  nerve may accidentally be severed.    The management of impacted canine teeth requires skilful  handling and careful observation on the part of an oral and  maxillofacial surgeon. If any tooth is absent in the dental  arch after the normal time of eruption has lapsed, the surgeon  must investigate. The management of an impacted tooth is  simple if the basic principles of surgery are followed appro-  priately for all the teeth. The case must be evaluated care-  fully for proper diagnosis and treatment planning. Treatment  planning requires a multidisciplinary approach, and the gen-  eral dental surgeon must consult with the oral and maxillofa-  cial surgeon, orthodontist and paedodontist for achieving  optimal results.    Fig. 15.14 (a-h) Schematic diagram showing steps in the surgical  removal of impacted mandibular canine. (a) Incision to raise a trapezoi-  dal flap, (b) Mucoperiosteal flap reflected and the bone overlying the  crown removed using bur and chisel, (c) Crown of impacted canine  exposed, (d) Elevator is applied in an attempt to luxate the tooth. (e) if    elevation unsuccessful tooth division is performed using bur, (f) Crown  removed and more of the root exposed to create a purchase point on the  root using bur, (g) Root removed using an elevator applied at the pur-  chase point, (h) Closure of the incision    Fig. 15.15 (a—m) Shows the clinical and radiographic images of the | Overlying odontome exposed, (h) Odontome removed and crown of 33  steps in removing a labially impacted canine by odontectomy. Impacted exposed. (i) Sectioning of crown of 33, (j) Removal of crown and root  left mandibular canine (yellow circle) with an associated odontome (a) _ of 33 followed by debridement, (k) Suturing completed (1) Specimen of  OPG showing impacted 33, (b) CT Axial view, (c) Coronal view, (d) 33 with follicle and odontome, (m) Pressure dressing applied to reduce  Sagittal view. (e) Intra-oral view, (f) Mucoperiosteal flap reflected, (g) oedema    Dewel B. The upper cuspid: its development and impaction. Angle  Orthod. 1949;19:79-90.   Archer WH. Chapter 5, Oral and maxillofacial surgery, vol. 1. Sth  ed. Philadelphia, PA: WB Saunders; 1975. p. 325.   Field HJ, Ackerman AA. The impacted upper Cuspid. Dent  Cosmos. 1935;77:378.   Thilander B, Jakobsson SO. Local factors in impaction of maxillary  canines. Acta Odontol Scand. 1968;26(2):145-68.    . Clark C. A method of ascertaining the position of unerupted teeth    ize an object in the anterior part of the maxilla. Br J Orthod.  1989;16:79C.    of impacted maxillary canines: a comparison of methods. Eur J  Orthod. 2001;23:25.   Kuftinec MM, Shapira Y. The impacted maxillary canine: I. review  of concepts. II. Clinical approaches and solution. J Dent Child.  1995;62:317-34.    Maverna R, Gracco A. Different diagnostic tools for the localiza-  tion of impacted maxillary canines: clinical considerations. Prog  Orthod. 2007;8(1):28-44.   Chaushu S, Chaushu G, Becker A. Reliability of a method for the  localization of displaced maxillary canines using a single pan-  oramic radiograph. Clin Orthod Res. 1999;2:194.   Alexander Katsnelson A, Flic WG, Susarla S, Tartakovsky JV,  Miloro M. Use of panoramic X-ray to determine position of impacted  maxillary canines. J Oral Maxillofac Surg. 2010;68:996—1000.  Preda L, La Fianza A, Di Maggio EM, Dore R, Schifino MR,  Campani R, et al. The use of spiral computed tomography in the  localization of impacted maxillary canines. Dentomaxillofac  Radiol. 1997;26:236-41.   Liu D, Zhang W, Zhang Z, Wu Y, et al. Localization of impacted  maxillary canines and observation of adjacent incisor resorption  with cone-beam computed tomography. Oral Surg Oral Med Oral  Pathol Oral Radiol Endod. 2008;105:91-8.   Walker L, Enciso R, Mah J. Three-dimensional localization of max-  illary canines with cone-beam computed tomography. Am J Orthod  Dentofacial Orthop. 2005;128(4):418.   Vermette ME, Kokich VG, Kennedy DB. Uncovering labially  impacted teeth: apically positioned flap and closed-eruption tech-  niques. Angle Orthod. 1995;65(1):23-32.   Chaushu S, Becker A, Zeltser R, Branski S, Vasker N, Chaushu  G. Patients perception of recovery after exposure of impacted teeth:  a comparison of closed-versus open-eruption techniques. J Oral  Maxillofac Surg. 2005 Mar;63(3):323-9.   Crescini A, Clauser C, Giorgetti R, Cortellini P, Pini Prato  GP. Tunnel traction of infraosseous impacted maxillary canines. A  three-year periodontal follow-up. Am J Orthod Dentofac Orthop.  1994 Jan;105(1):61-72.   Incerti-Parenti S, Checchi V, Ippolito DR, Gracco A, Alessandri-  Bonetti G. Periodontal status after surgical-orthodontic treatment  of labially impacted canines with different surgical techniques:  a systematic review. Am J Orthod Dentofacial Orthop 2016  Apr;149(4):463-472. Review.   Schmidt AD, Kokich VG. Periodontal response to early uncover-  ing, autonomous eruption, and orthodontic alignment of pala-  tally impacted maxillary canines. Am J Orthod Dentofac Orthop.  2007;131:449-55.   Quirynen M, Op Heij DG, Adriansens A, Opdebeeck HM, van  Steenberghe D. Periodontal health of orthodontically extruded  impacted teeth. A split-mouth, long-term clinical evaluation. J  Periodontol. 2000 Nov;71(11):1708-14.   Chapokas AR, Almas K, Schincaglia GP. The impacted maxillary  canine: a proposed classification for surgical exposure. Oral Surg  Oral Med Oral Pathol Oral Radiol. 2012 Feb;113(2):222-8.  Dalessandri D, Parrini S, Rubiano R, Gallone D, Migliorati  M. Impacted and transmigrant mandibular canines incidence, aeti-  ology, and treatment: a systematic review. Eur J Orthod 2017 Apr  1;39(2):161—169. Review. (Open Access).    Open Access This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.  org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropri-  ate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.    The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in    a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.   Endodontic surgery is a dental procedure to treat apical peri-  odontitis in cases that did not heal after nonsurgical retreat-  ment or, in certain instances, primary root canal therapy [1].  It is the branch of dentistry that deals with the diagnosis and  treatment of lesions of endodontic origin, which cannot be  treated by or do not respond to conventional root canal  therapy.    Guerini documented the first endodontic surgery as incision  and drainage of an acute endodontic abscess, approximately  1500 years ago [2]. Infected root sections were removed,  and the healthy tooth portion was retained in attempting to  cure infected teeth for about 200 years. Histological bone  regeneration was demonstrated in treated cases of infected  periapical lesions in 1930 [3]. For a long time, pulpless teeth  were implicated in a plethora of systemic disorders like  nephritis and arthritis by the exponents of the focal theory of  infection [4].   The terms apicoectomy, periapical surgery, periapical  endodontics, root end surgery, apical microsurgery, and sur-  gical endodontics have been used in the literature.  Apicoectomy, which means cutting the root apex, limits the  understanding of the procedure, which includes removal of  the irritants in the root canal system and the periapical  pathology as well. Today, endodontic surgery is one of the  most puissant branches of dentistry and falls in the twilight  zone among surgery, dentistry, and endodontics. Recent    D. Simon (2)  Department of OMFS, Government Dental College,  Trivandrum, Kerala, India    © The Association of Oral and Maxillofacial Surgeons of India 2021    advances in techniques and materials have resulted in a para-  digm shift toward a more judicious strategy for treating peri-  apical pathologies. The new benchmark for success is tissue  regeneration. Nonsurgical retreatment for endodontic fail-  ures and surgical endodontics has been radically revolution-  ized by the introduction of the “microscope”.   A periapical lesion is defined as any radiolucent image  exceeding | mm in the periapical vicinity of the tooth.  Lesions with a mean diameter > 5 mm are classified as large  lesions, and those less than or equal to 5 mm are classified as  small lesions [5]. In lesions greater than 10 mm, tooth extrac-  tion may or may not be done after considering factors like  tooth mobility, pain, and the periodontal condition [6]. A  periapical lesion may be noticed clinically or radiographi-  cally at a dimension of 5 mm [7].   1. Failures of nonsurgical treatment (treatment should have  been done at least twice)   presence of post and core or if the tooth is fractured at its    1. Radiological findings of apical periodontitis and/or symp-  toms associated with an obstructed canal (the obstruction  proved not to be removable, displacement of the obstruc-  tion did not seem to be feasible, or the risk of damage was  too great)    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1-15-1346-6_16    2. Extruded material with clinical or radiological findings of  apical periodontitis and/or symptoms continuing over a  prolonged period   3. Persisting or emerging disease following root canal treat-  ment when root canal retreatment is inappropriate   4. Perforation of the root or the floor of the pulp chamber  and when it is impossible to treat from within the pulp  cavity    Classification of Endodontic Surgery [8]  1. Fistulative Surgery  (a) Incision and drainage  (b) Cortical trephination  (c) Decompression procedures  2. Periapical Surgery  (a) Curettage  (b) Root end resection  (c) Root end preparation  (d) Root end filling  3. Corrective Surgery  (a) Perforation repair  (i) Mechanical (iatrogenic)  Gi) Resorptive  (b) Periodontal management  (i) Root resection  (ii) Tooth resection  (ii) Intentional replantation    The nasal floor, maxillary sinus, inferior alveolar, and mental  and greater palatine neurovascular bundles offer potential  road blocks to the surgeon.    If the roots of the maxillary anteriors are very long and the  lesion extends superiorly, proximity to the nasal floor should  be borne in mind. Eberhardt et al. have commented that the  mesiobuccal root apex of the maxillary second molar is clos-  est to the sinus floor and the buccal root apex of the maxillary  first premolar is the farthest [10]. The greater palatine neuro-  vascular bundle presents a risk while working on the palatal  roots of maxillary molars. If the vessel is severed, pressure  must be applied by packs or bone wax and the eventuality of  external carotid artery ligation should not be precluded.  Vertical releasing incisions on the palate are to be eschewed,  and if these are unavoidable, it is prudent to place the same  between the maxillary canine and first premolar, where the  artery has a narrow caliber. Palatal roots can be accessed  buccally or across the sinus or palatally (direct approach).  The contour and depth of the palatal vault greatly determine  the surgeon’s accoutrement; greater the depth, greater the  comfort.   Inadvertent loss of root tips into the maxillary sinus  should be avoided and retrieved endoscopically if such a  situation arises. Sinus communications, if they occur sel-  dom, pose an impediment to healing neither are they impli-  cated in sinustis [11]. The sinus membrane _ usually  regenerates, and a thin bone forms at the apex [12]. Shallow  vestibule, palatally or lingually inclined roots, compounds  the surgeon’s difficulties.    In the mandible, the facial artery, mental nerve, and inferior  alveolar neurovascular bundle should be reckoned with. The  facial artery can be safeguarded if incisions placed in the  vicinity of the mandibular first molar are not extended  beyond the vestibular depth. The route taken by the inferior  alveolar neurovascular bundle is of particular significance. It  winds buccal (second molar) to lingual (first molar) and then  again buccal (the second premolar) before it exits the mental  foramen [12]. In the vertical dimension, the mandibular sec-   il. Apex of mesiobuccal root of the maxillary 0.83  second molar and sinus   2. Apex of buccal root of the maxillary first 7.05  premolar and sinus   4. Apex of mesiobuccal and distobuccal root of the 2.8  maxillary first molar and sinus   3 Apex of the mandibular second molar and Ball  mandibular canal   6. Apex of mesial root of the mandibular first molar 6.9  and mandibular canal   Ue Apex of the mandibular second premolar and 47  mandibular canal   8. Buccal cortical plate and distal root of the 8.5  mandibular second molar    ond molar is closest to the canal as when compared to the  mandibular first molar or second premolar. For all practical  purposes, the mandibular second molar is not conducive to  endodontic surgery and should be attempted bearing in mind  these encumbrances. The mandibular anteriors offer a par-  ticular challenge while performing perpendicular root resec-  tion [12].   Excessive salivation, shallow vestibule, thick alveolus,  and small rima oris are other determinants. A comprehensive  assessment of all these variables is mandatory prior to  embarking upon endodontic surgery (Table 16.1).    16.6 Investigations  Until recently, periapical radiographs were the workhorse of  endodontic surgery. Their obvious shortcomings were due to  compression of three-dimensional structures into a two-  dimensional image and geometric distortion of anatomy. In  the year 2000, Cone Beam Computer Tomography (CBCT)  was introduced to dentistry. The limited CBCT offers higher  resolution, and images are displayed in three planes: axial,  coronal, and sagittal. Simultaneously, radiation dose is com-  parable to panoramic x-rays, and superimposition of neigh-  boring structures is obviated [12]. The relationship between  the teeth apices and anatomic structures, variations in root  morphology, additional canals, and external root resorption  are just a few of the diagnostic conundrums that can be  assessed via CBCT.   Surgical workup also includes complete blood count, rou-  tine urine examination, viral markers, and a thorough medi-  cal history. Appropriate regulation of insulin, anticoagulants,    and other drugs should be undertaken in liaison with the  attending physician.   A well-informed patient is the best patient. The impor-  tance of informed consent cannot be overdrawn, and the  patient is entitled to know about the prognosis, benefits, and  surgical complications, anticipate damage to vital structures,  and follow up. Communication regarding the above details is  mandatory, and the patient should be made aware of alternate  treatment modalities like extraction followed by implant  placement.    Nonsteroidal anti-inflammatory drugs (NSAIDs) in con-  flation with a long-acting local anesthetic can scale down  postoperative pain. Ainsworth surmised that routine use  of prophylactic antibiotics in periapical surgery is unwar-  ranted [12]. A presurgical mouth rinse with chlorhexidine  gluconate (0.12%) will reduce the salivary bacteria sig-  nificantly, especially their growth on sutures and wound  margins, but may obtrude with fibroblast reattachment to  the root [12].   Most patients tolerate the surgical procedure under local  anesthesia but for the apprehensive, conscious oral sedation  with benzodiazepines or nitrous oxide/oxygen inhalation  should be opted for. Diazepam 10 mg can be started on the  night before the surgery, and another dose can be adminis-  tered | hour before the procedure [13].    The merits and demerits of various local anesthetics have  been elaborated in detail elsewhere in this book. Conventional  nerve blocks are augmented by local infiltration. Of equal  momentousness is the preference for the vasoconstrictor.  Adrenaline in concentrations ranging from 1:50,000, 1:  100,000, and 1:200,000 have performed commendably.    Incisions can be placed with no.11, no. 12, no 15, or no. 15-C  blades (Fig. 16.1). Sharp, blunt dissection and elevation of  the mucoperiosteal flap are accomplished by a Molts’ or  Howarths’ periosteal elevator (Fig. 16.2). Endodontic tissue  retractors like Austin, Seldon, or Minnesota should be judi-    ciously selected in order to minimize trauma to the muco-  periosteal flap and neurovascular bundles (Fig. 16.3).  Overlying bone is cut with No.4/6/8 round burs or 701/702  fissure burs (Fig. 16.4). These can be used to resect the root  apex as well. Surgical handpiece with 45 ° angle head and  rear air exhaust is advocated. Sharp surgical curettes like  Lucas curette, angled periodontal curettes, and spoon exca-  vators help to remove the inflamed soft tissue from the bony  cavity (Fig. 16.5).   Root end resections can be done either with conventional  burs or lasers (Er-YAG or Ho-YAG lasers) [14, 15].    The advantages of lasers include greater patient comfort,  decreased vibrations, lesser surgical site contamination, and  minimal trauma to the juxtaposed tissues.   Ultrasonic microsurgical tips are invaluable for root end  preparation. Earlier, hand files and rotary burs were used. Teflon  sleeves, pluggers, and Messing gun-type syringes can be used to  place various root-end filling materials like MTA (Fig. 16.6).  Review of literature validates the superiority of microsurgical  techniques over conventional surgery (97% to 59%) [1]. The  dental operating microscope, ultrasonic tips, and diamond  coated micromirrors (Fig. 16.7) have found their niche in the  surgeon’s armamentarium. Micromirrors (Fig. 16.8) can be  used to inspect the buccal and lingual walls of the retrocavity.  Microsurgical scalpels are useful for incising the intrasulcular  areas and dissection of the interproximal papillae.    The aims of periapical surgery are to visualize and debride  the affected area and provide hermetic seal at the root end  that aids in periodontal regeneration (Figs. 16.9, 16.10 and  16.11). Gutmann and Harrison [4] have categorized flaps as    The main difference is that marginal interdental tis-  sues are included in the full flaps, whereas the latter con-  serves them. Researchers opine that limited flaps prevent  loss of papilla height, but careful adaptation of the  reflected soft tissues rarely causes changes in gingival  attachment level. It is vital to preserve the root attached  tissues. In the absence of periodontal pathology, ana-  tomic and functional status quo can be maintained via  full mucoperiosteal flaps. Elevating palatal flaps is by    and large a cumbersome affair. If the clinical situation  demands a palatal approach, the envelope and triangular  flaps can be considered. Contrary to popular teaching,  vertical incisions can be placed on the palate, rather than  stretching and renting a flap, which may impede healing.  This approach is best reserved for palatal roots for poste-  riors. Anterior palatal cysts can be accessed labially or  palatally, according to the surgeon’s discretion. To aid in  surgical access, it is prudent to pass a long suture through    Fig. 16.10 Clinical image of a trapezoidal flap for periapical lesion in  lower anterior region    the palatal flap and have the assistant retract the tissue.  Table 16.2 details the advantages and disadvantages of  various types of flaps that can be used for endodontic  surgery.    1. Straight or parallel incisions are preferred over severely  angled ones, in order to preserve the supraperiosteal blood  supply of the attached gingiva and submucosa. Fewer ves-  sels and collagen fibers are transected with parallel inci-  sions, resulting in less hemorrhage and flap shrinkage   2. Root eminences of canines and maxillary premolars are  covered by thin bone with a poor blood supply and should  be spared. Incisions should be placed between adjacent  teeth on interdental bone   3. Flaps should lie on solid healthy bone. At least 5 mm of  bone should be present between the defect and incision  line   6. The entire mucoperiosteum should be included in the  flap; this is imperative for uneventful healing   8. The horizontal incision should extend at least one tooth  beyond the pathologic area of interest    The position of the tooth in the arch, the dimensions of the  periapical pathology, gingival recession, and the presence of  artificial crowns also determine the choice of the incision  that is placed.    The horizontal element of a full mucoperiosteal flap com-  mences in the gingival sulcus and severs the gingival attach-  ment fibers to the crestal bone. The interdental papilla should  be incised at the midcol level. While incising a limited flap,  the horizontal component must conform to the contour of the  marginal gingiva and should be 2 mm apical to the depth of    Trapezoidal flap (full) horizontal, intrasulcular  incisions, two divergent angled, vertical incisions  Horizontal /envelope flap (full). No vertical releasing Limited use  incision    root amputations  Papilla based flap (full)  Shallow first incision at the base of the papilla  second incision directed to crestal bone    Submarginal curved/semilunar flap (limited). Curved  incision in alveolar mucosa and attached gingiva    Submarginal scalloped rectangular /Luebke-  Ochsenbein (limited). Scalloped horizontal incision  follows the shape of the marginal gingiva on the  attached gingival    the gingival sulcus. The vertical incision should begin in the  alveolar mucosa and proceed toward the crown till it abuts  the horizontal incision. To achieve the above objectives  fresh, sharp blades should be opted for.   Hemostasis and healing are enhanced if the entire muco-  periosteal flap is elevated as a single unit, due to adherence  of the flap with its microvasculature. The broad end of the  elevator can be maneuvered beneath the vertical incision, a  few millimeters from the junction of the horizontal and verti-  cal incision in the attached gingiva. This preserves the  supracrestal root-attached fibers. This is followed by coronal  dissection, and forces are directed toward the periosteum and  bone. This technique is termed undermining elevation and  should be continued throughout the length of the horizontal  incision and apically to the alveolar mucosa [4]. An approxi-  mate distance of 1 cm from the apex should be exposed for  adequate access. The bleeding tags seen on the bone contain  periosteum that aids in healing and reattachment of the flap.    The soft tissues must be gently retracted to preclude the pos-  sibility of inadvertent crushing. This may lead to flap  hypoxia, swelling, ecchymosis, and/or delayed healing. The    retractor of a correct size should be selected and placed on  cortical bone in such a way that the tissue is prevented from  engaging with rotary instruments.   The periosteal surface of the flap should be irrigated with  sterile, cool, and physiologic saline to keep it hydrated. The  superficial surface is more resistant to dehydration due to the  stratified squamous epithelium [16, 17].    Once the flap is raised, the surgeon encounters either intact  cortical bone over the lesion or the lesion sans cortical  bone. In the former scenario, it is imperative to localize the  lesion and remove bone in the adjacent periapical area.  Well-angled radiographs can aid in this aspect. Sounding  the bone with the sharp end of the periosteal elevator can  also be useful, as there is a change in resonance when one  approaches the diseased area. It is also prudent to identify  the root by calculating twice the crown length and then  shave the thin bone at the apex. If digital technology is  used, the distance from the alveolar crest to the root apex  can be measured using the ruler function [3]. The root is  smooth, hard, and yellow in color, surrounded by a peri-  odontal ligament, and does not bleed on probing. Methylene   Bone is vulnerable to thermal damage at any temperature  above the normal body temperature. This is the crucial aspect  of periapical surgery and influences the choice of burs, cool-  ants, and handpieces. Bone when subject to temperatures  between 40 °C and 50 ° C undergoes a spectrum of irrevers-  ible changes. These include reduction in microcirculation,  tissue necrosis, fatty cell infiltration, and decrease in alkaline  phosphatase.   While selecting bone cutting burs, sharp ones with wide  spaces between the flutes are preferred. Round burs meeting  these criteria promote excellent healing. Chilled saline effec-  tively reduces the heat produced and flushes out the debris,  thus enhancing efficiency. Excess pressure applied to the  bone is detrimental to the tissues and handpiece. Gentle  shaving or brushing motion must be used in short, multiple  phases.   Hirsch et al. have used a piezoelectric device to create a  bony aperture while performing apicoectomies in maxillary  anteriors. The buccal bone was removed, preserved in Hank’s  Balanced Salt Solution (HBSS), and later replaced in the  bony crypt after the procedure, thus acting as an autologous  bone graft. This is feasible in cases where there is minimal  bone loss or in the presence of intact bone over the lesion  [18].   The bony aperture should be wide enough to permit  visual and surgical access into the lesion, enabling the  insertion of bone curettes and excavators. In traditional  root surgery, the size of the aperture is approximately  8-10 mm and 3-4 mm in microsurgery. The rate of heal-  ing is faster when the size of osteotomy is smaller.  Granulomas and granulation tissues exhibit a propensity  to bleed profusely, hindering the surgery. To circumvent  this, local anesthetic with a vasoconstrictor can be  injected within. Using a curette of appropriate dimen-  sion, the surgeon works from the periphery toward the  center. The instrument is inserted between the tissue and  the lateral edge of the cavity with its concave face toward  the bone. This is continued all around the circumference  of the cavity and slowly progresses toward the depth of  the crypt in a scraping manner. After freeing all the tis-  sue, it is gently grasped with a pair of tissue forceps and  immersed in 10% buffered formalin solution. The speci-  men should not be left to dry. Lin et al. opine that com-  plete curettage is not mandatory, if the irritant is  eliminated [19]. Though a majority of periapical lesions  have been diagnosed histopathologically as granulomas  or cysts, there have been documented reports of perfectly  innocuous looking periapical lesions diagnosed as odon-  togenic keratocysts, central giant cell granulomas, or  squamous cell carcinoma [20, 21].   Regeneration of alveolar bone, periodontal ligament, and  cementum in the periapical area can be encouraged by remov-  ing the diseased root end tissues and placing a root end seal to  stop the recontamination of the periapical region. Resection  of apical 3 mm of the root apex will eliminate 78% of apical  ramifications and 93% of lateral canals, which could contain  material that would contribute to the periradicular disease  [12]. The isthmus area should be included in the resection in  roots with multiple canals. Anatomical obstructions, broken  instruments, and perforations can be removed, orthograde  sealing can be assessed, and trapped lingual tissue can be  curetted out. In the case of apical fenestration, the apex can be  reduced below the surrounding cortex to enable bone forma-  tion over the apex. The resection should enable the surgeon to  prepare a root end cavity and place a restoration within.   A smooth, flat resected surface is considered ideal. This  should be assessed for cracks, anatomical variations, and  orthograde obturating material by means of an operating  microscope at high power magnification and methylene blue  staining [2]. The resection is made in order to surround the  filling by normal dentin. Conventionally, a 30-45" bevel was  placed, but the advent of the microscope has enabled a resec-  tion perpendicular to the long axis of the tooth. This substan-  tially decreases the number of exposed dentinal tubules. Cohen  opines that this aids in root end cavity preparation beyond the    coronal extent of the root surface and apical stresses are well  distributed, thus reducing apical fractures [11].   After the perpendicular root resection, the root must be  conditioned to remove the smear layer produced. This  exposes the collagen matrix of dentin and promotes growth.  5% aqueous citric acid has been used for this purpose. EDTA  and tetracycline have also been studied, but have not found  clinical popularity.   A 3 mm-deep Class I cavity is prepared along the long axis  of the tooth, in order to place the filling material [22].  Ultrasonic tips have been specifically designed for this pur-  pose. The tips produce less smear layer, need less beveling,  and can be inserted through a smaller aperture. However, the  ultrasonic vibrations can predispose to root fractures. This  can be minimized when it is used at the lowest setting and  with water coolant. Ultrasonic tips coated with stainless  steel, diamond, or zirconium nitride are superior to uncoated  tips. If the tips have a curvature of 70° or more, they are prone  to fracture [23]. The root end filling is placed into the pre-  pared cavity. When bonded materials like Retroplast are  used, no root end preparation is needed; the filling is placed  like a dome onto the resected root. This is termed bonded cap  approach.   It is imperative to have a dry bloodless field prior to place-  ment of the root end filling regardless of the setting proper-  ties of individual filling materials. To achieve this,  adrenaline-saturated pellets, bone wax, Gelfoam, surgical,  calcium sulfate, thrombin, collagen, or ferric sulfate may be  used. Electrocautery may also be used, but this may delay  bone healing.   Amalgam used to be the quintessential retrograde filling mate-  rial as it is cheap, easy to use, and radio opaque. However, it  may stain the tissues and is sensitive to moisture [3]. Research  has yielded a plethora of retrofilling materials, which has    SI.  No Material Composition Characteristics  1. Zinc oxide Zinc oxide powder Affected by  eugenol eugenol liquid powder-liquid ratio.  Eugenol can inhibit  prostaglandins and  cause fibroblast  toxicity; final  compound has high  solubility  2. Intermediate Zinc oxide, polymethyl Not affected by  restorative methacrylate powder, powder liquid ratio.  material eugenol, and acetic No evidence of  (IRM) acid—Liquid cementogenesis  3. Super EBA Zinc oxide, aluminum No evidence of  (epoxy oxide, natural resins- cementogenesis  benzoic acid) powder, eugenol, and  o-methoxybenzoic  acid-liquid  4. Glass Calcium alumino Moisture sensitive.  ionomer silicate—powder and Risk of detachment  polyacrylic acid liquid from teeth  5. Retroplast Paste A- Bis-GMA/ Dentin bonding  TEGDMA 1:1, benzoyl composite resin.  peroxide N,N-di-(2- Hard tissue  hydroxyethyl)-p-toluidine, formation seen,  and butylated probably cementum.  hydroxytoluene; Paste-B Evidence of PDL  ytterbium fluoride aerosil regeneration seen.  ferric oxide Biocompatible.  Adequate setting  time and  compressive  strength.  Strict control of  hemorrhage is  mandatory  6. Mineral Calcium silicate, calcium Evidence of  trioxide carbonate, bismuth cementogenesis  aggregate sulfate, calcium sulfate, seen. Long setting  (MTA) and calcium aluminate time ~ 3 h,  unaffected by blood  and moisture.  Gray MTA can  cause tooth  discoloration.  Least amount of  microleakage.  Less marginal gap  formation.  Better adaptation  7.  Bioceramics Calcium silicate, Newer material.  monobasic calcium Biocompatible.  phosphate, and zirconium Antimicrobial    After placing the root end filling, a radiograph must be  obtained to assess its quality. If the radiograph reveals an  incomplete root resection or an inadequate retrofill, the sur-  geon must rectify the above-said deficiencies. These are the  most common surgical pitfalls that contribute to endodontic  surgical failures.   The surgical site is gently cleaned and irrigated with ster-  ile saline to remove debris of hemostatic agents and filling  materials. Bone grafts or guided regeneration barriers can be  placed into the crypt if indicated, but sterile technique should  be adhered to, at all times to obviate infection. Calcium  phosphate bioceramics, bioactive glass composite, and bio-  active self-setting cements have been evaluated in vitro as  well as in vivo [24, 25]. The flap is repositioned and deli-  cately compressed with a moist gauze to vent out the excess  blood, and tissue fluids 4—0 Silk or 6-—O monofilament suture  materials are used. Tissue adhesives like cyanoacrylate and  fibrin may be used as alternatives in the future. Suturing  commences at the corners, approximately 2-3 mm from the  wound margins. Interrupted sutures and sling sutures work  well for closure of full mucoperiosteal flaps. Continuous  locked suturing can also be done in marginal flaps as it  reduces the time taken for suturing.   Following wound closure, moist gauze is placed on the  flap for 5 min to stabilize clot formation and hemostasis.  Compressing the flap with sterile ice packs in the immediate  postoperative period minimizes the thickness of the fibrin clot  and enhances wound healing. Intermittent cold compresses  for 20 min on the day of surgery aids in patient comfort.  Analgesics are prescribed, and verbal and written instructions  are given to the patient and primary care provider. The wound  must be cleaned gently with cotton. Chlorhexidine mouth-  wash is beneficial and can be continued till sutures are  removed, i.e., on the fifth day postoperatively. Sutures can be  removed after 3 days in microsurgical procedures.    The dynamics of healing in endodontic surgery involve vari-  ous mechanisms germane to the nature of the individual tis-  sues. The soft tissue incision heals by primary intention,  whereas the bone defect and resected root surface heal via sec-  ondary intention. The endpoint of surgery should be regenera-  tion, rather than repair where the normal tissue architecture  and function are restored instead of a fibrous scar tissue.   The soft tissue healing progresses through three phases,  ie., inflammatory, proliferative, and maturation. The inflam-  matory phase begins with clot formation. The local microvas-  culature contracts, the platelets release serotonin, and a  protein-rich exudate enters the wound site. Intravascular  aggregation of platelets forms a platelet plug, and the extrin-    sic and intrinsic pathways are activated. This results in a ran-  domly arranged thick fibrin clot. Within 6 hours of clot  formation, polymorphonuclear leukocytes enter the wound  and decontaminate the area by phagocytosis of bacteria. Their  activity tapers off by 96 hours; monocytes and macrophages  continue the phagocytic activity. A reduction in macrophages  hampers the next phase of wound healing, especially in the  older population where there is a step down of estrogen regu-  lation of macrophages. The proliferative phase is dominated  by fibroplasia and angiogenesis. The granulomatous nature of  the wound transforms into granulation tissue by the activity  of cytokines like platelet derived growth factor (PDGF),  fibroblast growth factor (FGF), and insulin-like growth factor  (IGF-1). By the third day, fibroblasts lay down Type III col-  lagen, which matures to Type I. Myofibroblasts orient them-  selves parallel to the wound surface and contract, thus  drawing the wound edges together. Concurrently, capillary  networks form within the wound stimulated by proangiogenic  factors like vascular endothelial growth factor (VEGF), FGF,  transforming growth factor a, 6B (TGF-a, B), and interleukin-1  (IL-1). An epithelial seal is formed on the surface of the fibrin  clot by the first day. In the next 5—7 days, the wound matures  by the formation of larger collagen bundles.   In the osseous crypt, there is a hematoma and proliferation  of granulation tissue, callus formation, and woven bone deposi-  tion, which is converted to lamellar bone. These events are  regulated by TGF-B, PDGF, FGF, IGF, and bone morphogenic  protein (BMP). At the root end, cementum forms over the  resected surface. Cells responsible for cementogenesis are  believed to originate from the ectomesenchymal cells in the  tooth germ. By 28 days, the root end is covered by cementum.    1. Flap necrosis and breakdown, due to poor design and  careless handling   3. Exposure of the maxillary sinus, which heals in a major-  ity of cases   6. Staining of gingival tissues due to retrofilling materials  like amalgam    Clinical and radiographic assessments are made to determine  the outcome of periapical surgery. The Periapical Index  (PAI) has been used for radiographic assessment in both sur-    1. Healed cases show complete clinical and radiographic  normalcy with no signs and symptoms or residual  radiolucency   2. Healing cases show a decrease in the size of the radiolu-  cency and clinical normally within 4 years of surgery   3. Diseased cases show radiolucency, new, increased,  unchanged, or decreased after 4 years, regardless of  radiographic appearance    Loupes, endoscopes, and the operating microscope have  enhanced visualization of the operating field and thereby the  quality of surgery.   It has a rod lens system, camera head, and control unit with a  monitor and light source placed on a mobile rack. The depth  of perception is comparable with the naked eye. Tactile per-  ception is excellent; diseased tissue behind and between  roots can be visualized. Irrigation fluids can be used without  clouding the visual field. Fabbro and Taschiere have reported  success rates of 91.1 and 90.7% using the endoscope [27].  They offer rapid and easy adjustment of the viewing angle,  direct viewing sans micromirrors, which is versatile and  transportable.    The resolution of the human eye is 0.2 mm. The power can  be increased by moving closer to the surgical field, but can  pose strain to the eye. Hence, magnifying lenses and illumi-  nation are used to bypass this problem.   The operating microscope offers up to 30 times magnifi-  cation, coaxial light supply, and shadow free illumination.  200 mm objective lenses and 180° inclinable binoculars are  optimum configurations. Light can be sourced from either  xenon or quartz halogen bulbs. Digital camera, video cam-  era, and co-observation tube are included in the setup.  Endodontic microsurgery amalgamates magnification, illu-  mination, and microinstrumentation, leading to predictable    treatment outcomes. Deeper root end cavities can be pre-  pared, which follow the contour of the root, hence minimiz-  ing lateral perforation [28]. The high cost of the equipment  and need for specialized training deter many from adopting  this tool on a routine basis, but the high success rates should  be sufficient encouragement for clinicians and patients to  adopt this new tool.    The role of mesenchymal stem cells in regeneration of periapi-  cal tissues has been explored with great enthusiasm. Dental  pulp stem cells (DPSCs) and those from exfoliated deciduous  teeth are multipotent in capacity and can be used along with  scaffolds and signaling molecules [29]. These entities, when  combined in the ideal proportion, aim to recreate the embry-  onic milieu, hence augmenting the biological concepts of  wound healing. The future may usher in radical changes in our  approach to endodontic surgery in terms of materials and tech-  niques with respect to regenerative medicine.    Acknowledgments Dr. Khaleel Ahamed Thaha, Assistant Professor,  Department of Conservative Dentistry and Endodontics, Government  Dental College, Kozhikode, Kerala.    1. Frank CS, Sweta BS, Meetu RK, Bekir K, Syngcuk K. Outcome  of endodontic surgery: a meta analysis of the literature — part I:  comparison of traditional root end surgery and endodontic micro-  surgery. JOE. 2010 Nov;36(11):1757-65.   3. Franco PB, Karlis V. In: Kademani D, Tiwana PS, editors.  Apicoectomy in atlas of oral and maxillofacial surgery. St. Louis,  MO: Elsevier; 2016.   4. Gutmann JL, Harrison JW. Surgical endodontics. St. Louis, MO:  Ishiyaku euro America; 1994.   5. Quality assurance guidelines. Chicago: American Association of  Endodontists; 1987, p. 1-27.   6. Simsek-Kaya G, Saruhan N, Yapia-Yavuz G, Ertas U. A decision  analysis for periapical surgery: retrospective study. J Clin Exp  Dent. 2018 Sep;10(9):e9 14—20.   7. El-Swiah JM, Walker RT. Reasons for apicoectomies: a retrospec-  tive study. Endod Dent Trauma. 1996;12:185-91.   9. European Society of Endodontology. Quality guidelines for  endodontic treatment: consensus report of European society of  endodontology. Int Endod J. 2006;39:921-30.   10. Eberhardt JA, Torabinejad M, Christiansen EL. 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Ultrasonic root end  preparation in apical surgery: a prospective randomized study. Oral  Surg Oral Med Oral Pathol Oral Radiol Endod. 2007;104:84.    23. Walmsley AD, Lumley PJ, Johnson WT, Walton RE. Breakage of  ultrasonic root-end preparation tips. J Endod. 1996;22:287.   24. Komath M, Varma HK, Annie J, Vinod K, Simon D, Ramanathan  M, Bhuvaneshwar GS. Designing bioactive scaffolds for dental  tissue engineering in regenerative medicine: laborotary to clinic.  Berlin: Springer; 2017.   25. Simon D, Manuel S, Varma HK. Novel nanoporous bioceramic  spheres for drug delivery application: a preliminary in vitro  investigation. Oral Surg Oral Med Oral Pathol Oral Radiol. 2013  Mar;115(3):e7-14.   27. Del Fabbro M, Taschieri S. Endodontic therapy using magnification  devices: a systematic review. J Dent. 2010 Apr;38(4):269-75.   28. von Arx T. Failed root canals: the case for apicoectomy (periradicu-  lar surgery). J Oral Maxillofac Surg. 2005;63:832-7.   29. Shiehzadeh V, Aghmasheh F, Shiehzadeh F, Joulae M, Kosarieh E,  Shiehzadeh F. Healing of large periapical lesions following delivery  of dental stem cells with an injectable scaffold: new method and  three case reports. Indian J Dent Res. 2014 Mar—Apr;25(2):248-53.    Lieblich SE. Periapical surgery: clinical decision making. Oral  Maxillofac Surg Clin N Am. 2002;14:181.   Leiblich S. Current concepts of periapical surgery. Oral Maxillofacial  Surg Clin N Am. 2015;27(3):383-2.    Open Access _ This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.  org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropri-  ate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.    The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in    a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.    The human mandible has no one design for life. Rather it adapts and remodels through the seven stages of  life, from the slim arbiter of things to come in the infant, through a powerful dentate machine and even  weapon in the full flesh of maturity, to the pencil-thin, porcelain like problem that we struggle to repair in the   The management of discontented denture patients by the act  of preprosthetic surgical procedures to enhance the denture-  bearing areas of the intraoral cavity is a daunting task, which  has been performed by the oral and maxillofacial surgeon  from time immemorial. Preprosthetic surgery encompasses a  distinguished and evolving category of soft and hard tissue  procedures.   Pre-prosthetic surgery has emerged from being virtually  unknown, passed through a period of opposition and into a  state of venerability, and has ultimately made a powerful  impact on oral surgery and prosthetic dentistry alike.   Willard [1] is honoured to be the first American dentist to  call attention to proper preparation of the mouth for full den-  tures. Beers [2] in 1876 advocated excision of the alveolus  after extraction of teeth, especially if the alveolar process is  unusually exhibiting protuberance. Surgery has always been  an integral part of the preparation of alveolar ridges for den-  tures. The last few decades have witnessed an escalating  interest in preprosthetic surgery, which has harboured the  development of many new techniques.    Electronic Supplementary Material The online version of this chap-  ter (https://doi.org/10.1007/978-98 1-15-1346-6_17) contains supple-  mentary material, which is available to authorized users.    B. John (4)  Department of Oral and Maxillofacial Surgery, Government Dental  College, Kottayam, Kerala, India    © The Association of Oral and Maxillofacial Surgeons of India 2021    Immediately after extraction, the socket will suffer a reduc-  tion in the dimensions both in buccolingual and apicocoronal  aspects. This catabolic process can be counteracted by the  placement of implants. The resorption of the walls occurs in  two phases, which are overlapping in nature. The first phase  is characterised by the resorption of bundle bone and replace-  ment with woven bone. The second phase involves the outer  surfaces. The exact aetiology for this bone loss is unknown.  Roux [3] opined the loss of alveolar bone occurring after  tooth loss in the old age is an illustration of disuse atrophy.  According to studies by Wolff [4], the mass and structure of  the bone can get adapted to the mechanical demands. The  resorption is a multifactorial, biomechanical process that  results from a combination of anatomic, metabolic, and  mechanical determinants. Since all of these factors vary from  one patient to the next, these different cofactors may com-  bine in infinite variety of ways, thus explaining the variations  in resorption between patients. So ridge resorption is a  chronic, progressive, irreversible, and cumulative phenome-  non resulting from physiologic, environmental and patho-  logic components.    Mercier [5] illustrated the general resorptive changes  that take place in an edentulous ridge. He summarised  the stages as follows:    1. The ridge is wide enough at its crest to accommo-  date the recently extracted teeth.  . The ridge becomes thin and pointed.  3. The pointed ridge flattens to the level of the basal  bone.  4. The flattened ridge becomes concave as the basal  bone resorbs.    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1-15-1346-6_17    The pattern of resorption in maxilla differs from that of  the mandible. Also, the pattern varies with the site in maxilla  and mandible. The extensive study by Cawood and Howell  [6] depicts the following conclusions.   Basal bone does not change shape significantly. But if  subjected to harmful local effects, it undergoes change.   Alveolar bone exhibits significant changes in shape in  both horizontal and vertical axes.   In anterior mandible, the bone loss is vertical and hori-  zontal, but in posterior mandible, the bone loss is mainly  vertical.   In anterior maxilla, the bone loss is both vertical and hori-  zontal. The same pattern is exhibited in the posterior maxilla.  To summarise, the stage of bone loss varies anteriorly and  posteriorly and between the jaws.   Ridges can be classified by their shape. There are V-shaped,  U-shaped and knife edged types. The U shaped is the ideal  while the V shaped, though successfully distribute the stress  but may be unable to retain the peripheral seal during the jaw    movements. Knife edged ones are a constant source of sore-  ness under the stress.   A more scientific categorisation is made by Cawood and  Howell [6].    The preliminary step is the assessment of the patient, which  commences from the history taking to the physical examina-  tion. The role of radiograph is relevant especially the pan-  oramic view to reveal the deep-seated disorders. Storer [7]  found 32% of edentulous patients had an asymptomatic  pathologic condition, which warrants the need for radio-  graphic examination. Crandell and Trueblood [8] also  advised radiographic examination to rule out the presence of  pathologies, root remnants, and even impacted tooth.  Radiographic assessment is one of the parameters in detect-  ing bone quality.    Type 1: bone in which almost the entirety is composed  of homogeneous compact bone.   Type 2: bone in which a thick layer of compact bone  surrounds a core of dense trabecular bone.   Type 3: bone in which a thin layer of cortical bone sur-  rounds a core of dense trabecular bone.   Type 4: bone characterised as a thin layer of cortical  bone surrounding a core of low-density trabecular  bone of poor strength.    Ridge correction procedures  Hard-tissue correction  Alveoloplasty  Alveolectomy  « Reduction of,  Genial tubercles  Mylohyoid ridge,  Maxillary tuberosity.  - Correction of tori, exostoses.  Soft-tissue correction  - Frenectomy  Labial  Lingual  Excision of hypertrophic tissues   The term refers to the restructuring or resurfacing of the  alveolar process bone to provide a functional skeletal rela-  tionship. Simple plasty insists on the reshaping of the alveo-  lar bone during the extraction procedure. The sharp edges of  the alveolus will impede the healing process with symptoms  of pain and discomfort. The shape of the ridges with suffi-  cient width and height should be able to distribute the forces  properly.   Preservation of alveolar bone is of utmost importance in  the extraction procedure. Simple alveolar contouring  includes compression and infracture of the socket, but over-  compression and reduction should be avoided. If extractions  are carried out before the prosthesis fabrication, attempts are  made to preserve the alveolus. In multiple extractions,  postextraction irregularity exists, which warrants the need  for extended alveoloplasty. Here, mucoperiosteal flap may  be raised by a crestal incision to get adequate access for the  bone reshaping. Extreme care has to be taken during flap  elevation since the soft tissues are tightly adhered to the bony  irregularities. The use of bone rongeur or file is needed to    smooth the edges, but large irregularities may be rectified by  rotary instruments. Ensure saline irrigation to keep the tem-  perature below 47 degrees to prevent necrosis. Once the hard  tissue is removed, the excess soft tissue is trimmed to prevent  the instability of the prosthesis. Closure with absorbable  sutures in running or lock stitch fashion is achieved.   In situations where the alveolar process is prominent but  regular, the need for alveoloplasty by the removal of inter-  septal bone and collapsing the buccal or labial cortical plates  to meet the palatal or lingual plates is warranted. This method  was propagated by Dean and Mackay [10]. This is an ideal  procedure in case of immediate denture placement and usu-  ally carried out in the anterior region (Fig. 17.1a and b). This  is done by the placement of vertical bone cuts in the canine  region through subperiosteal tunnels. Apply the digital pres-  sure to infracture the bone. If unsuccessful, the labial plate  can be fractured with an osteotome inserted through a hori-  zontal subperiosteal tunnel made through the vertical lateral  incision. The bone distal to the canine is rounded off to main-  tain the contour. Mucosa is sutured appropriately to retain  the new position of the cortices and if needed an acrylic  splint may be used to stabilise it.    Genioglossus muscle is one which is adhered to the lingual  aspect of the anterior mandible and when the resorption con-  tinues, the genial tubercle becomes more prominent and  along with the attached muscles creating a displacement of  prosthesis. In this case, the pronounced tubercle may be  trimmed and released. This procedure may be done alone or  in combination with procedures suggestive of lowering the  floor of the mouth.   A crestal incision from the midline to the midbody of man-  dible is made to get adequate access, followed by dissection  in subperiosteal fashion, thus exposing the tubercle and the  attached muscle. Muscle may be excised from the bony  attachment by using a monoplanar electrocautery with care  to be taken to achieve haemostasis or else chance of airway  embarrassment by the occurrence of expanding hematoma.  The exposed genial tubercle is trimmed by round or fissure  bur. Further smoothening is made by bone file. The flap is  returned to the original position and closed by nonresorbable    Fig. 17.1 (a) Incision for intercortical alveoloplasty (b) closure of wound    sutures. Anderson [11] proposed reattaching the genioglosus  and geniohyoid muscles at a lower level. Here, he advocated  using a Sagittal incision in the midline in the periosteum and  exposing the genial shelf. The tubercle is reduced and the  incision is closed with absorbable sutures.    In cases of extensive resorption, the ridge becomes promi-  nent and creates hurdle for the smooth placement of denture;  hence, the need for ridge reduction occurs. The denture  flanges impinge on the sharp mylohyoid ridge and patient  experiences pain and discomfort. The advent of implants  may obviate the need for such a surgical procedure, yet in  many cases where implant placement is not feasible, the den-  tures become a necessity and the mylohyoid ridge reduction  needs to be accomplished.   The procedure can be carried out under local anaesthesia or  sedation. After successful nerve block, the incision is carried  out along the crest of the ridge in the posterior mandible area  followed by subperiosteal dissection and exposure of the  mylohyoid ridge and the attached muscle (Fig. 17.2a and b).  The muscle is detached and relieved. The residual ridge is  smoothed with file, flap returned, and closed with sutures  (Fig. 17.2c). Care is ensured to obtain haemostasis.    Maxillary tuberosity may be enlarged in size and it engorges  the intermaxillary space and interferes with denture place-  ment. The reduction of the tuberosity may be needed to cre-  ate space for the placement of dentures. Generally, the    intermaxillary distance should be at least 1 cm when  patients are placed into the correct or planned vertical  dimension of occlusion. The excessiveness of the tuberos-  ity and the need for its reduction can be assessed by some  clinical manoeuvres. An instrument like a dental mirror can  be used to assess the vertical clearance by passing it  between the tuberosity and retomolar tissues. The mirror  may be positioned in the lateral aspect and the patient is  instructed to open and close mouth so as to determine the  need for reduction of tuberosity in the horizontal plane. The  pneumatisation status should be ascertained before the  reduction procedure is undertaken since the maxillary sinus  may descend into the tuberosity. So a radiographic exami-  nation is essential prior to surgical management. An ellipti-  cal incision is made followed by subperiosteal dissection.  The engorged tuberosity is trimmed to the desired level and  excessive tissue is removed from both buccal and palatal  side. The amount of bone removal can be dictated by a sur-  gical guide that was created from study models. Rotary  instrumentation, rongeur and a bone file may be used to  remove the bone. The flaps are trimmed to leave the excess  redundant tissue and sutured in place (Fig. 17.3a—f).  Guernsey [12] proposed a different technique for the reduc-  tion of the tuberosity. He advised placing a horizontal inci-  sion superiorly in the vestibule from the premolar area to  the posterior aspect of the tuberosity and a mucoperiosteal  flap is released inferiorly to get access to the tuberosity  region. Any excessive soft tissue of fibrous nature is  removed from within the flap and excessive bone is also  removed by using suitable instruments. To correct the  redundancy of tissues, soft tissue may be removed from the  superior aspect of the incision and flap is sutured back to  the periosteum and a stent is placed. This method claims to  increase the vestibular depth to some extent (Fig. 17.4a—d).  Antral communication should be checked and if present  managed accordingly.    Fig. 17.2 (a) Incision along the crest of the ridge (b) flap raised and bone trimmed (c) sutured the incision    Tori, meaning ‘to stand out’ or ‘lump in Latin, refer to innocu-  ous bony outgrowths. The aetiology of the occurrence is  unclear. Early description of the occurrence of tori is found in  the Proceedings of the Royal Society of Medicine by Rickman  Godlee [13], which was followed by the reports from various  authors and later beautifully summarised by Garcia Garcia  [14]. In dentate individuals, the removal of torus may not be  needed unless it impedes with functions or it generates dis-  comfort. But in edentulous, the presence of tori precludes the  smooth placement of denture, so the removal becomes manda-  tory. Other indications include mucosal surface getting trau-  matised with frequent episodes of ulceration, presenting with  deep undercuts and multiple nodules and psychological issues.  Literature also suggests tori as donor sources of autogenous  bone for intraoral grafting procedures. Morraes et al. [15] and  Hassan et al. [16] describe the versatility of the grafts from  torus for reconstructive methods.   Classification of tori was initially proposed by Kolas [17],  who classified them according to number of nodes and their    placement as bilateral single, bilateral multiple, unilateral  single, and unilateral multiple [18].    Haugen [19] formulated the categorisation of torus  based on the size. It is illustrated as.    Type A—small tori into less than 2 mm in their largest  diameter.   Type C—large- and more than 4 mm in their largest  diameter.    Fig. 17.3 (a) Bulbous tuberosity, (b) incision placed and flap raised (¢ and d) reduction, (e and f) sutured incision    Fig. 17.4 Clinical photograph showing (a) bulbous tuberosity (b) incision (c) flap reflection (d) sutured wound   As in any surgical procedures, here also the general systemic  condition of the patient may be ascertained and the patient  should be warned of the potential complications like the per-  forations leading to oronasal communication and wound  dehiscence. To overcome this problem, preoperatively an  impression may be made and cast is fabricated and splint is    prepared. Palatal tori may be of different shapes, like lobu-  lated or nodular. The morphology of the torus dictates the  incisions required to expose it. Surgical access is accom-  plished by various types of incisions, “C-” or “U-” shaped  incision, palatal incision or double “Y” incision also known  as open-door technique. Most commonly used is double Y  incision (Fig. 17.5a—f). After successful anaesthesia, a mid-  line incision in anteroposterior direction is made from a few    Fig. 17.5 (a) Incision, (b) flap raised, (c) multiple grooves made, (d) final trimming by acrylic trimmer, (e) excess soft tissue trimmed, (f)    mm ahead of the anterior margin of the torus and continued  posteriorly to the most posterior visible point of the torus.  Oblique-releasing incisions may be placed at the anterior  end of the midline incision and may be extended laterally  and anteriorly to end lateral to the lateral margins of the  torus. From the posterior end of the midline incision without    violating the soft palate, posterior releasing incisions may be  placed to extend obliquely in a lateral and posterior direc-  tion. Thus, a fair access is obtained. The subperiosteal flap is  raised. The small torus can be easily removed by round. But  in case of large ones, grooves are created and separated into  discrete segments with bur and then by osteotome (Fig. 17.6).    Copious irrigation is done to clear the debris and flap reposi-  tioned in primary fashion. The fabricated stent may be placed  to avoid the haematoma and the dead space formation.    The lingual tori are found in the lingual aspect of the alveolar  ridge in the canine and premolar regions. They vary in size  and shape; some are pedicled, while others are broad based.  An intrasulcular incision without releasing is made from the  lingual midline to a point beyond the posterior limit of the  tori. In edentulous case, the incision may be placed in the  crest of the alveolar ridge. A full-thickness flap is raised to  expose the tori and if needed local anaesthetic may be  injected in the area to balloon the tissues for easy elevation of  the flap. The vertical-releasing incision should be avoided to  prevent the vascularity compromise.   The lingual torus may be removed by bur or osteotome.  Smaller ones can be easily removed by bur, but the larger  require cleavage plane created by bur and later completed by  osteotomes. After the removal of the tori, it is essential to  check the surface and clear of the irregularities by the use of  rongeur and bone files. The flap repositioned and sutured.    It is a benign osseous hypertrophic formation with more pre-  dilections to the maxilla. A mucoperiosteal flap is elevated  after adequate infiltration of the mucosa. The bone is resected    and smoothed with an osteotome or a bur. The smooth place-  ment of the prosthesis is achieved by the facilitation of the  errorless foundation, constituted by both hard and soft tis-  sues. In many cases, the hard-tissue framework may be nor-  mal, but the soft-tissue impediments affect the stability of the  prosthesis. So, the correction of the interferences by the  abnormal soft tissues is needed.   Apart from hard tissues, sometimes soft-tissue interfer-  ences inhibit the smooth placement of the prosthesis. The  unfavourable soft-tissue framework affects the stability of  the prosthesis and needs correction by various procedures.    This is commonly associated with prolonged wearing of an  ill-fitting denture. The condition is recognised as reddened,  nodular, or papillary excrescences arising from the palatal  mucosa. It can be seen in areas where the denture flanges  rest. Removal is accomplished by local anaesthesia or seda-  tion (Fig. 17.7).    Active and strong frenal attachments interfere with the place-  ment of dentures and the relief of attachments are needed.  Various incisions like v-y, z plasty, and diamond-shaped  incisions are used in frenectomy procedures.   In the edentulous state, the abnormal frenal attachment gets  irritated by the denture flanges leading to instability. The  denture area can be relieved but it may be unaesthetic, so  the need for frenectomy arises. Z plasty is used to eliminate  the abnormal attachment. Another method is the V- Y pro-  cedure but has a disadvantage of creating excessive bulk of  tissue at the depth of vestibule. The operative procedure is  as follows (Fig. 17.8a, b and c). It is carried under local  anaesthesia, but the tissue should not be overdistended. The  lip is extended and everted to tense the frenum. The  V-shaped piece of tissue is held by tissue forceps or Allis  clamp, and an incision is made down to the periosteum on  either side of the frenum. Resorbable sutures are preferred  since the removal is difficult in this area. The first suture  should be placed at the depth of the vestibule and should  engage the periosteum to prevent the loss of the vestibular  depth (Fig. 17.9a-e).    Fig. 17.7 Clinical photographs showing (a) lingual papillary hyperplasia (b) suturing after excision    Fig. 17.8 Clinical photographs showing (a) abnormal attachment of frenum (b) tissue held with mosquito forceps (c) suturing    Fig. 17.9 (a) low attached frenum, (b) frenal tissue grasped by forceps, (¢ and d) diamond-shaped tissue removal, (e) closure    If the frenal attachment is near the crest of the lingual aspect,  it will displace the denture. So the need for relief of the high  attached frenum is needed. This procedure can be done    under local anaesthesia or general anaesthesia (Fig. 17.10a—  d). When local anaesthesia is used, bilateral lingual nerve  block and infiltration are used. The tongue is grasped with  traction sutures or forceps and the attachment of frenum to  the ridge is cut and the wound is closed with sutures. In    Fig. 17.10 (a) High attached lingual frenum, (b) excision of frenum, (c and d) closure    some, a more extensive procedure is needed. Here, a trans-  verse incision is made between ventral aspect of tongue and  caruncle of submandibular duct. Sectioning of some fibres  of the genioglosus muscle may yield greater degree of free-  dom. Diamond-shaped defect is closed with interrupted  sutures. Postoperative pain is managed by analgesics and  oedema controlled by steroids. There may be some ecchy-  mosis in the floor of the mouth.    They are defined as the procedures surgically designed to  uncover the existing basal bone of the jaw by repositioning  the overlying mucosa and muscle attachments to an infe-  rior position in mandible or to a superior position in max-  illa. This will enable to accommodate the larger denture    flanges, thus contributing to stability and retention (Tables  17.1 and 17.2).    The reduction or obliteration of the sulcus is caused by [1]  resorption of the alveolar process, [2] abnormally high mus-  cle attachment in mandible or low on the maxilla, [3] scar  tissue resulting from trauma or infection from the contiguous  soft tissue.   Vestibuloplasties are carried out in mandible and maxilla.  In mandible, both labial and lingual vestibuloplasties are per-  formed. Stability of a denture can be improved by deepening  the mandibularsulcus, generating more attached tissues over  the functional ridge, and permanently maintaining the    ¢ Lingual sulcus extension with resectio  of mylohyoid muscle and with or  without lingual skin graft — Trauner®°    ¢ Lingual sulcus extension with resection  of mylohyoid ridge, muscle and lingual  flap cover of bone — Obwegeser*!   ¢ Ridge skin grafting vestibuloplasty combined with  total lowering of floor of mouth — Obwegeser*".    improved vestibular depth. Mandibular vestibuloplasty is  carried out to predictably increase and maintain the func-  tional alveolar ridge.   Preoperative preparation of the vestibuloplasty patients  includes history, clinical examination, and suitable radio-  graphs. Radiographs, especially orthopantomograph, help to  evaluate the ridge height. The commonly performed ones are  discussed in this section.    The credit of this procedure goes to Kazanjian [21], later  modified by many in the literature. Kethley and Gamble [45]  modification finds more acceptance in the literature. The  selection criteria for this procedure are the minimum bone  height of 15 mm between the mental foramen areas.   Stabilised by stent or dentures  The raw area in the lower lip is  allowed to heal by secondary  epithelisation   The facial surface of the  ridge is chosen to raise  the flap   The use of skin grafts  over the denuded surface  to facilitate healing.  Tortoerlli [46]  modification  Fenestrations are made in  the periosteum along the    and extended to the crest of the  ridge from the lip incision placed  initially   The technique involves the administration of local anaesthe-  sia followed by mucosal incision. The mucosal flap is ele-  vated and pedicled near the crest of the ridge (Fig. 17.1la  and b). An incision is placed near the superior portion of the  periosteum. A supraperiosteal dissection is carried in the  inferior direction, thereby removing the attachments of the  muscular and connective tissues to the indicated vestibular  depth. The labial periosteal margin is sutured to the incised  lip mucosa. This is followed by the suturing of the pedicled  flap to the periosteum at the depth of the vestibule.    Indicated in cases where the lip switch procedure is not pos-  sible due to the inadequate tissue availability. The options  permissible in such cases were either secondary epithelisa-  tion or covering the denuded areas with grafts. The former  became less popular because of wound contraction leading  to the loss of vestibular depth. Here, the desired alveolar  height between the mental foramina is not less than 10 mm  in contrast to the minimum of 15 mm in lip switch.   An incision is placed at the mucogingival junction and a  supraperiosteal dissection carried out to the desired vestibu-  lar depth. During the dissection, care is taken not to dissect  more than half of the mentalis muscle to avoid the chance of    Fig. 17.11 Lip switch vestibuloplasty (a) Labial mucosa pedicled near  the crest of the ridge (b) pedicled flap sutured to the depth of the  vestibule    the ptosis of the submental tissues referred as ‘witch chin’.  The margin of the incision is now sutured to the periosteum  in the depths of the vestibule. The harvested graft is now  placed over the recipient bed after ensuring adequate haemo-  stasis. The graft is contoured to the correct shape, fenes-  trated, placed, and fixed on the periosteum with the help of  stent or by sutures.   The grafts may be harvested from cutaneous or mucosal areas  or allogenic in nature. The best sites for skin graft harvesting  are medial thigh or caudal to the iliac crest, where fewer  adnexal structures are present in the skin. Areas where smaller  grafts are needed, mucosal grafts may be considered, which  may be taken from the palate or buccal mucosa. Cultured skin  grafts are also becoming popular but lack the mechanical and  functional elements of the autogenous grafts. The narration of  techniques of grafting is beyond the scope of this chapter.    The severe atrophy of the mandible in the anterior region  makes the genial tubercles prominent and affects the stability    of the denture by the attached muscles. The exposure of the  tubercles and the detachment of the genial muscles are  accomplished by the procedure of lingual vestibuloplasty.  Initially proposed by Kazanjian [21] and later modified by  Lewis [32], the disadvantage of this procedure may be the  loss of tongue function and difficulty in swallowing, which is  encountered if more than half of the muscle is removed.   Incision is made in the anterior aspect of the crest of the alve-  olar ridge and subperiosteal flap is elevated. Dissection con-  tinued till the prominent genial tubercle with the attached  muscle is encountered. The genial muscles are separated  from the ridge and the tubercle is trimmed with bur and  smoothed with bone file. The flap along with the muscle is  lowered to the desired depth and it is maintained in the new  position by stent and extraoral sutures. The exposed area is  allowed for secondary re-epithelisation.   If the amount of the resorption is severe that it results in the  displacement of the denture by the action of mylohyoid, then  lowering of the mylohyoid muscle should be considered.  This can be done alone or in combination with labial vestibu-  loplasty. The amount of the available depth can be assessed  by aclinical manoeuvre, by placing a gloved finger along the  lingual side of the mandible and asking the patient to touch  the palate with the tip of the tongue. If this action displaces  the finger, lowering the floor of mouth should be  considered.   Incision is made from the retromolar area to the premolar  area of the lingual aspect of the alveolar crest. Mucoperiosteal  flap is raised and exposes the mylohyoid and the overlying  periosteum. Dissection in the supraperiosteal plane is  preferred to avoid the chance of the damage of the lingual  nerve. The muscle with the flap is lowered to the desired  depth. Sutures are passed through the mylohyoid and mucosa  and secured to the skin extraorally. The exposed area is  allowed for secondary re-epithelisation (Fig. 17.12a—f).    Brown [47|—incision similar to Trauner’s but a full-thickness  mucoperiosteal flap is reflected to reveal the mylohyoid  ridge. Here, the muscle is detached and the ridge is  smoothed. The difference here is the sulcus is not deep-  ened, but the problem with the ridge prominence is solved.   Caldwell [33]—here a crestal incision is employed and a  supraperiosteal approach to access the mylohyoid ridge  and the attached muscle. The flap is sutured to the original    position. The new position is secured by a stent or a modi-  fied denture. Instead a polyethylene tubing can be also  used to maintain the position.   Edlan [29]—here, a combination of the lip switch vestibulo-  plasty and lowering the floor of mouth is accomplished.  Incision is made in the buccal sulcus instead of the crest  of alveolar ridge. Plastic tubes are used to maintain the  depth of the sulcus.   plasty, submucous sulcoplasty to remove the buccinator  insertion and bilateral mylohyoid ridge reduction.    In atrophic maxilla, the alveolus may be accentuated by dif-  ferent options; earlier, vestibuloplasty was the choice of pro-  cedure. But the results achieved were not long lasting  because of the continued resorptive process. So, the advent  of augmentation came into action. In severe resorbed and  atrophic ridges of Cawood and Howell [6] classes IV—VI,  augmentation became mandatory. Unfortunately, this area of  preprosthetic surgery has gained little attention, possibly  there seemed to be no effective operation for ridge augmen-  tation using an extraoral method; moreover, the penetration  into the oral cavity during the procedure was deemed tanta-  mounting to failure, as the surgeons are reluctant to perform  the elective augmentation of mandible (Table 17.3).   Classification of alveolar ridge deficiency by Kent et al.  [49] acts as a yardstick to identify the ridge nature and the  grafting options.    Class 1—alveolar ridge is adequate in height but inad-  equate in width, usually with lateral deficiencies or  undercut areas. Patient receives hydroxyapatite  alone.   Class 2—alveolar ridge is deficient in both height and  width and presents a knife-edge appearance. Patient  receives hydroxyapatite alone.   Class 3—alveolar ridge has been resorbed to the level  of the basilar bone producing a concave form in the  posterior areas of mandible and a sharp bony ridge  form with bulbous mobile soft tissues in the max-  illa. Patient receives hydroxyapatite with or without  autogenous cancellous bone.    Fig. 17.12 Lingual  vestibuloplasty methods (a)  Normal, (b) Trauner, (c)  Brown, (d) Caldwell, (e)  Hopkins, (f) Edlan   Carried over the posterior areas from  retromolar pad to the premolar region with  supraperiosteal dissection    Ridge is smoothened after the  mylohyoid muscle is released  Not used alone but is  combined with other    Autogenous bone grafting remains the ideal option to rec-  tify the deficiency but accompanied by disadvantages like  the need for hospitalisation and general anaesthesia, donor  site morbidity, extensive surgical procedure, professional  expertise and patient compliance.   The resorption of the mandible has been so extensive that it  results in the severely atrophic condition and liable for a  pathological fracture. In such a case, augmentation has to be  achieved in the inferior border. The procedure was originally  proposed by Marx and Sanders [50] and later modified by  Quinn [51]. The procedure carries the advantages of non-  obliteration of the sulcus, allowing the placement of the    interim denture and making the secondary vestibuloplasty  easier. But the procedure carries the burden of an extraoral  scar and the chance of altering the facial appearance. Access  to the lower border is gained by different ways by different  authors. Some literature supports the use of incision used in  the neck dissection, viz. a supraclavicular incision. It extends  from the anterior border of sternocleidomastoid to the oppo-  site counterpart. According to Sanders [50], a continuous  submandibular incision from angle to angle is sufficient.  Ridley and Mason [52] proposed the use of three small sub-  mandibular incisions connected by subperiosteal tunnels.  The latter is opposed by Sanders [50] for the high chance of  resorption by the pressure on the graft. Dissection is carried  out to expose the inferior border of mandible. Two ribs of 15  to 20 cm long are harvested and bent to adapt the shape.  Three or four transosseous holes are drilled in the lower bor-    der of mandible and wires are passed through these holes.  One rib is placed against the lingual aspect and the other  abutted against the buccal aspect. The space between the ribs  is packed with available cortical chips. Ribs are secured in  place by interosseous wires in circumferential pattern.  Closure is achieved in layers and pressure dressing is applied.  The narration of the technique of graft harvesting is beyond  the limit of this chapter.    The superior border enhancement is needed [53] in cases  where the resorption is so severe that the height of the man-  dible is insufficient to accommodate the prosthesis or in  cases where the patient suffers from pain during mastication,  secondary to the pressure on the mental neurovascular bun-  dle (Fig. 17.13a and b).   Recipient site is prepared and the mucosa is infiltrated with  local anaesthetic solution containing epinephrine to achieve  haemostasis. Crestal incision from the retromolar area to the  opposite retromolar area is made and mucoperiosteal flap is  raised. Care to be taken to avoid the mental nerve if it is near  the superior border. Depending on the position, it may be  lowered or freed. The existing superior border is exposed and  prepared to receive the graft. The lingual flap is reflected to  the level of the mylohyoid muscle. Davis and colleagues [54]  described the technique of ridge augmentation, which uses  two rib grafts of 15 cm. The ribs may be adjacent or alter-  nate. One rib may be contoured by vertical scoring on the  inner surface or by bending. Leake [55] recommends split-  ting the rib longitudinally and then bending it with forceps.  The second rib is cut into pieces and packed against the solid  rib. Before the placement of the rib, the superior aspect of the  mandible is already prepared and suited to receive it. The  posterior aspect of the rib should be in contact with mylohy-  oid shelf, slightly on the lingual aspect of the ramus. The ribs    are fixed by three interosseous wires, one placed through  each mylohyoid shelf and the other in the anterior region in  the midline. Flaps returned to cover the graft.   Concept of placing bone grafts between the osteotomised  segments of the mandible was initially proposed by Barros  saint and Pasteur [56] and later experimentally proved by  Danielson and Nemarich [57]. The horizontal osteotomy is  achieved by an incision made inferior to the crest of the  ridge. The length of the incision is determined by the area to  be augmented. Incision is designed from the retromolar area  to the other. A buccolabial mucoperiosteal flap is raised and  the flap is greatly undermined to get adequate coverage of  the graft. Issues are left untouched to ensure the patency of  the vascular supply. The horizontal osteotomy is made by  burs and osteotomes, and precise osteotomy is obtained by  use of saws. The cut may be placed either above or below the  canal, depending on the proximity to the inferior border.  Transosseous holes are drilled in the lower and upper seg-  ments. The harvested graft is interposed between the osteot-  omised segments and stabilised by the wires. The flap is  returned and approximated with sutures (Fig. 17.13c and  Table 17.4).    The procedures of vestibuloplasty and floor of the mouth  lowering may not be always successful to provide a stable  and adequate basis for the prosthesis. The situation of the  reduced vertical height needs to get addressed. Harle [58]  published a report of an original and promising method to  augment the alveolar ridge by means of a pedicled bone    Fig. 17.13 (a and b) Superior border augmentation, (c) Interpositional grafting    graft. This procedure possesses less danger of infection and  rejection of the transplant and of resorption by remodelling  processes. The muscles and periosteum in the labial side are  reflected and the mandible in the frontal region is osteot-  omised and split in the length. The mobile lingual fragment  is slid upwards, together with the adherent soft tissue, and  fixed to the basal part of the mandible by intraosseous and  perimandibular wiring. Bosker [59] improved this method by  combining the osteotomy and the vestibuloplasty and lower-  ing of the floor of the mouth in a one-stage procedure.   The advantage of this modified technique of Bosker [59]  is it needs only single operation and hospitalisation of the  patient, the prosthesis can be made in 4—6 weeks sooner, and  the operative procedure is simpler.   Sladen and peterson [60] describe the body sagittal oste-  otomy and raising the lingual cortical portion of the mandi-  ble without detaching the lingual soft tissues for the intact  vascular pattern. The raised lingual ridge is positioned in the  new place, while the buccal counterpart is augmented with  cancellous marrow. This procedure is now referred to as  visor osteotomy in the literature.   The incision and the mode of raising the mucoperiosteal  flap is essentially the same as that used in the horizontal oste-  otomy as described earlier. Sagittal cut is made between the  buccal and lingual cortical plates from the third molar to the  opposite third molar area. Precise cutting is achieved by the  use of oscillating and reciprocating saws. The lingual seg-  ment, which is pedicled to the mylohyoid, digastrics and  genial musculature and the soft tissues, is elevated vertically  and fixed in the preplanned position with wires through the  transosseous holes. The lateral aspect of the elevated seg-  ment may be filled with the cancellous bone to compensate  the height deficiency created by the vertical repositioning.  The flap is returned and wound is closed by sutures.    Iliac bone crest and rib have traditionally been applied to  augment the jaws. Boyne [61] suggested a bone regeneration  method, which employs a vitalium mesh tray containing hae-  matopoietic bone marrow encased in a nylon-reinforced    Bone graft between the osteotomized  segments of the mandible- Barrors Saint and    Millipore filter. The filter prevents the connective tissue ele-  ments accessing the defect and thereby enhances the osseous  regeneration. The concern regarding the graft material is the  resorption shrinkage in the future. Many attempts are done  by surgeons to minimise the resorption shrinkage of the  grafted bone. Danielson and Nemarich [57] advocated the  subcortical insertion of bone graft. Farell [62] and associates  went ahead with interpositional bone graft with simultane-  ous vestibuloplasty. Sanders and Cox [50] proposed the use  of inferior border rib grafting for augmentation. Notched rib  can be contoured to the arc of the mandible, but 50% loss by  shrinkage is a great disadvantage with rib. The literature sug-  gests the use of pure cancellous iliac graft, iliac cortical—  cancellous sectional grafts with appropriate immobilisation  showing excellent healing even in the event of occasional  incision dehiscence.    A myriad of materials is used for the augmentation of the  atrophied ridge. It consists of resorbable and nonresorb-  able materials. The former finds its application in peri-  odontal pockets, while the latter is extensively used in the  management of alveolar atrophy. Hydroxyapatite, a cal-  cium phosphate material with physical and chemical attri-  butes, is nearly similar to dental enamel and cortical bone  has been successfully using for decades. Studies by Kent  et al. [49] and Drobeck et al. [63] illustrate the usage. Kent  et al. [49] used hydroxyapatite in combination with corti-  cocancellous autogenous bone for augmentation. This  combination provides additional strength to the mandible  as advised by Jarcho et al. [64]. Though block forms are  used by Frame and Brady [65], the granular forms also get  used in the augmentation process as guided by Kent et al.  [51]. When anterior mandible needs augmentation, a single  midline vertical incision is used, while for the complete  augmentation of mandible, bilateral vertical incisions  anterior to mental foramen are used. A subperiosteal tun-  nel is formed, which can be assessed by a dental mirror  and the syringe loaded with graft material is inserted    through the tunnel and delivered in place. After the tunnel  is filled with graft material, the incision is closed with  interrupted or horizontal sutures.   In maxilla, a single vertical incision in midline may be suf-  ficient, but in many cases bilateral incisions in the canine  regions may accommodate more amount of graft material. It  is similar to the procedure in mandible except for the palatal  dissection, where the ridge width is needed. Denture can be  placed at about | month in cases where augmentation is car-  ried out by hydroxyapatite alone or 6-8 weeks in which both  hydroxyapatite and bone are used together. If vestibuloplasty  is planned, Kent [49] advocated a waiting period of 8 weeks  after graft placement.    The art of designing the soft- and hard-tissue framework  for the smooth placement of the prosthesis is a challenging  task. This task is achieved by the meticulous planning and  execution of the planned presurgical procedures in a sys-  tematic manner. The intimidating impressive trends of  implantology might have downsized the charm of prepro-  sthetic surgery, yet in certain avenues the preprosthetic sur-  gical manoeuvres become inevitable. The magnitude of  vestibuloplasty and ridge augmentation procedures associ-  ated with the anticipated patient discomfort should not  demote the benefits of preprosthetic surgery in deserving  patients, where they suffer from pain or embarrassment by  a juggling ill-fitting denture. Such corrections may alter  their present situations and successful denture wearing is  ensured. So it is not possible to completely thwart or baffle  the procedures belonging to the preprosthetic surgery as an  obsolete one.    1. Willard AT. Preparing the mouth for full sets of artificial teeth. Dent  News Letter. 1853;6:238.   3. Roux W. Der Kampf der Teile im Organismus. Ein Beitrag zur  Vervollstindigung der mechanischen Zweckmissigkeitslehre.  Leipzig: Verlag von Wilhelm Engelmann; 1881.   4. Wolff J. Das Gesetz der Transformation der Knochen. Berlin:  August Hirschwald; 1892.   5. Mercier P. Residual alveolar ridge atrophy: classification and influ-  ence of facial morphology. J Prosthet Dent. 1979;8:24.   6. Cawood JI, Howell RA. A classification of the edentulous jaws. Int  J Oral Maxillofac Surg. 1988;17:232-5.   8. Crandell CE, Trueblood SN. Roentgenographic findings in edentu-  lous areas. Oral Surg Oral Med Oral Pathol. 1960;13:1343.    . Lekholm U, Zarb GA, Albrektsson T. Patient selection and prepa-    ration in Per-Ingvar Branemark et al Tissue-Integrated Prostheses.  Chicago: Quintessence; 1985. p. 199-209.    . Dean OT. Surgery for the denture patient. J Am Dent Assoc.    . Guernsey L. Preprosthetic surgery. In: Kruger GO, editor. Oral and    . Godlee RJ. The torus palatinus. Proc R Soc Med. 1909;2:175.  . Garcia Garcia AS, Martinez Gonzalez JM, GomezFont R. Current    status of the torus palatines and torus mandibularis. Med Oral Patol  Oral Cir Bucal. 2010;15:e353.    . Moraes Junior EF, Damante CA, Araujo SR. Torus palatinus: a    graft option for alveolar ridge reconstruction. Int J Periodontics  Restorative Dent. 2010;30:283.   Hassan KS, Alagl AS, Abdel H. A Torus mandibularis bone chips  combinedwith platelet rich plasma gel for treatment of intrabony  osseous defects: clinical andradiographic evaluation. Int J Oral  Maxillofac Surg. 2012;41:1519.   Kolas S, Halperin V, Jefferis K, Huddleston S, Robinson HB. The  occurrence of torus palatinus and torus mandibularis in 2478 dental  patients. Oral Surg Oral Med Oral Pathol. 1953;6:44.   Kalaignan P, Mohan JS, Jayakumar A. Determination of grad-  ing for maxillary and mandibular Tori- an in vivo study. Biomed  Pharmacol J. June 2018;11(2):679-88.   Haugen LK. Palatine and mandibular tori: a morphologic study  in the current Norwegian population. Acta Odontol Scand.  1992;50:65.   Reichart PA, Neuhaus F, Sookasem M. Prevalence of torus  Palatinus and torus mandibularis in Germans and Thai. Community  Dent Oral Epidemiol. 1988;16:61—4.   Kazanjian VH. Surgery as an aid to more efficient service with  prosthetic dentures. JADA. 1935;22:566-81.   Clark HB Jr. Deepening the labial sulcus by mucosal flap advance-  ment: report of a case. J Oral Surg. 1953;11:165.   Mcinthosh RB, Obwegeser H. Preprosthetic surgery: a scheme for  its effective employment. J Oral Surg. 1969;27:427.   Propper RH. Simplified ridge extension using free mucosal grafts. J  Oral Surg. 1964;22:469.   Hall RD, Steen O. Free grafts of palatal mucosa in mandibular ves-  tibuloplasty. J Oral Surg. 1970;28:565.   Godwin JG. Submucous surgery for better denture service. J Am  Dent Assocn. 1947;34:678.   Cooley DO. Method of deepening maxillary and mandibular sulci  to correct deficient edentulous ridges. J Oral Surg. 1952;10:27.  Edlan A, Mejchar B. Plastic surgery of the vestibulum inperiodon-  tal therapy. Int Dent J. 1963;13:593.   Trauner R. Alveoplasty with ridge extensions on the lingual side of  the lower jaw to solve the problem of a lower dental prosthesis. Oral  Surg. 1952;5:340.   Obwegeser H. Surgical preparation of the maxilla for the prosthe-  sis. J Oral Surg. 1964;22:127.   Lewis ET. Surgical correction to the sublingual region. J Am Dent  Assoc. 1963;67:364.   Caldwell J. Lingual ridge extension. J Oral Surg. 1955;13:287.  Ashley FN, Schwartz AN, Dryden MF. A modified tech-  nique for creating a lower lingual sulcus. Plast Reconstr Surg.  1953;22:204.   Szaba, Garner, Rumpel. Surgical preparation of the maxilla for  prosthesis. J Oral Surg. 1964;22:127.    . Esser JF. Studies in plastic surgery of the face. Ann Surg.    . Gillies HD, Millard DR. Principles and art of the plastic surgery.   Kent JN, et al. Alveolar ridge augmentation using nonresorbable  hydroxylapatite with or without autogenous cancellous bone. J Oral  Maxillofac Surg. 1983;41:629.   Sanders B, Cox R. Inferior border rib grafting for augmentation of  the atrophic edentulous mandible. J Oral Surg. 1976;34:897.   Kent JN, Quinn JH. Correction of alveolar ridge deficiencies with  nonresorbable hydroxylapatite. J Am Dent Assoc. 1982;105:993.  Ridley MT, Manson KG. Resorption of rib graft to inferior border  of mandible. J Oral Surg. 1978;36:46.   Blackstone CH, Parker ML. Rebuilding the resorbed alveolar ridge.  J Oral Surg. 1956;14:45.    Davis WH. Rib graft augmentation to the superior border of the  mandible. In: Preprosthetic oral and maxillofacial surgery. Saint  Louis: C V Mosby; 1980.   Leake D. Contouring split ribs for the correction of severe man-  dibular atrophy. J Oral Surg. 1976;34:940.   Danielson PA, Nemarich AN. Subcortical bone grafting for ridge  augmentation. J Oral Surg. 1976;34:887.   Harle F. Visor osteotomy to increase the absolute height of the  atrophied mandible- a preliminary report. J Maxillofac Surg.  1975;3:257.   Bosker, et al. Visor osteotomy and vestibuloplasty — A one-stage  procedure. Int J Oral Surg. 1977;6:127-30.   Slade E. Text book of maxillofacial surgery. In: Kruger GO, editor.  Personal communication. 6th ed. Saint Louis: C V Mosby; 1977,  July.   Boyne PJ. Restoration of the alveolar ridge by intramandibular  transposition osseous grafting. J Oral Surg. 1968;26:569.   Farrell CD. One stage interpositional bone grafting and vestibulo-  plasty of the atrophic maxilla. J Oral Surg. 1976;34:901.   Drobeck HP, et al. Histologic observation of soft tissue responses  to implanted, multifaceted particle and discs of hydroxylapatite. J  Oral Maxillofac Surg. 1984;42:143.   Jarcho M, et al. Hydroxylapaptite synthesis and characterization in  polycrystalline form. J Mater Sci. 1976;11:2027.   Frame JW, Brady CH. Augmentation of an atrophic edentulous  mandible by interpositional grafting with hydroxylapatite. J Oral  Maxillofac Surg. 1984;42:89.    Open Access _ This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.  org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropri-  ate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.    The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in    a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.    Modern implant dentistry started more than 50 years ago  when Dr. P.I. Branemark, a Professor from the University of  Gothenburg (Sweden), discovered in rabbit studies that tita-  nium chambers placed in the fibula became firmly anchored  in bone and could not be removed. Later, this direct bone-to-  implant contact was termed osseointegration [1]. He demon-  strated that titanium was structurally integrated into living  bone with a high degree of predictability and without long-  term soft-tissue inflammation or fixture rejection. He intro-  duced a two-stage threaded root form pure titanium implant  that was placed in patients in 1965. Therefore, Prof.  PI. Branemark is recognized as the most important pioneer  in modern implant dentistry.   The second pioneer is Prof. Andre Schroeder from the  University of Bern (Switzerland) experimented with proto-  type dental implants in the early 1970s and could demon-  strate first osseointegration in nondecalcified histologic  sections [1]. Both pioneers with their teams, independent of  each other, performed several preclinical and clinical studies  to establish the current scientific basis for dental implantol-  ogy. This was the start to successful osseointegration in  dentistry.   Between the 1970s and the 1980s, companies presented  different implant designs such as the Tiibingen implants  made of aluminum oxide, the IMZ titanium plasma-sprayed    Electronic Supplementary Material The online version of this chap-  ter (https://doi.org/10.1007/978-98 1-15-1346-6_18) contains supple-  mentary material, which is available to authorized users.    S. Ebenezer   Department of Oral Surgery and Stomatology, University of Bern,  Bern, Switzerland    V. V. Kumar - A. Thor  Department of Maxillofacial and Plastic Surgery, Uppsala  University Academic Hospital, Uppsala, Sweden    © The Association of Oral and Maxillofacial Surgeons of India 2021    surface, and the American Core vent implants made of tita-  nium aluminum vanadium alloy [1]. However, based on the  research from Albrektsson, commercially pure titanium  became the material of choice. One-piece implants slowly  evolved to two-piece implants to provide prosthetic  flexibility.   Over the next 15 years, implantology shifted from the  treatment of fully edentulous patients to the treatment of par-  tially edentulous patients as well. Prosthetic components for  the rehabilitation of different edentulous situations emerged,  and different surgical techniques and regenerative materials  were developed to improve the hard and soft tissues around  implants. Concepts of implant placement, loading, occlu-  sion, and maintenance evolved. Progress was made in  implant surface technology, which permitted the use of  shorter and narrower implants and reduced loading time [2].  Over the last decade, development has included strategies to  provide long-term stability with optimum functional,  esthetic, and phonetic results along with reduced complica-  tions. Advanced diagnostic aids, such as cone beam com-  puted tomography (CBCT), enabled proper assessment of  the surgical site and surgical planning to provide better out-  comes. Devices to examine implant stability objectively,  using resonance frequency analysis, improved the quality of  treatment provided. Digital technology is increasingly being  incorporated to improve accuracy, minimize invasiveness,  and fulfill esthetic demands. On the material front, ceramic  implants and implants using alloys of increased strength  have been introduced [2]. The field of implantology is a fast-  evolving one where the clinician has to be constantly updated  to keep pace.    within bone, such that the two could not be separated without  fracture [3]. Osseointegration was the term given to this con-    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1-15-1346-6_18    tact and refers to a direct bone to metal interface without  interposition of soft tissue seen at the optical microscope  level. Osseointegration is defined as “a direct structural and  functional connection between ordered living bone and the  surface of a load-carrying implant.” [4]    The cellular response after implantation depends on implant  surface characteristics, the stability, and heating injuries of  the host bone. Bone healing around implants involves a cas-  cade of cellular and extracellular biological events (similar  to fracture healing) until the entire implant surface is embed-  ded in bone.   The first biological component to contact the implant sur-  face is blood and blood cells from the surrounding vascula-  ture. These blood cells are activated and release cytokines  and other growth and differentiation factors on and around  the implant. Platelets undergo biochemical and morphologi-  cal changes due to contact with the implant surface and  undergo adhesion, spreading, and aggregation. They induce  phosphotyrosine, increase intracellular calcium, and cause  hydrolysis of phospholipids to form a fibrin matrix that regu-  lates cell adhesion and binding of minerals. This matrix is a  calcified afibrillar layer consisting of osteoid and lamina  limitans (organic layer) that is rich in calcium, phosphorus,  osteopontin, and bone sialoprotein [5]. This matrix acts as a  scaffold for osteogenic cells to migrate and differentiate to  form osteoid and trabecular bone (osteoconduction), which  will ultimately remodel to form lamellar bone around the  implant surface. The ability of the implant surface to retain  fibrin attachment during the initial phase is critical in deter-  mining if the migrating cells reach the fibrin clot. Roughened  surfaces promote osteoconduction. The chemistry of the  implant surface also influences osteoconduction, and for  example, hydrophilic implant surfaces have increased osteo-  conduction as compared to hydrophobic surfaces.   Peri-implant osteogenesis occurs in two ways with the  native bone as described by Osborn and Newesley in 1980.    1. Distance osteogenesis is a phenomenon that occurs from  the native bone toward the implant surface. The existing  bone surface provides a population of osteogenic cells,  which lay down matrix, slowly encroach on the fibrin-  meshwork-covered implant surface, and connect to this  network as osteogenesis progresses. Osteoclasts, derived  from mononuclear cells from the surrounding marrow  spaces, remodel the old bony surface before new bone is  laid down [5].   2. Contact osteogenesis occurs from the surface of the  implant toward the healing bone. The fibrin-covered    Fig. 18.1 Histology of osseointegration. Osseointegration is defined  as the direct apposition of bone onto the titanium implant surface as  seen in this histology section    implant surface that has attracted osteogenic cells slowly  has calcified afibrillar tissue forming into it. Blood vessels  and mesenchymal cells fill up the spaces in between.  Cement lines of poorly mineralized osteoid separate the  areas of resorption and initiation. Woven and trabecular  bone fill the initial gap and provide biological fixation to  the implant at about 10-14 days postsurgery. However,  the random orientation of the collagen fibers gives it  reduced mechanical properties as compared to lamellar  bone. This biological fixation differs from primary stabil-  ity obtained at implant placement and is commonly seen  with rough implant surfaces. Woven bone is slowly  remodeled in response to stress and mechanical loading  and replaced by lamellar bone until it reaches a high  degree of mineralization. At approximately 3 months  postimplant placement, the bone is a mixture of both  woven and lamellar matrix [6].  (Figure 18.1: histology  osseointegration)    An implant is considered to be osseointegrated when an  implant is in direct contact with the bone, and there is no  relative movement between the implant and the bone. In  other words, osseointegration is expressed clinically as long-  term state of stability of the implant in the vital bone.  According to Albrektsson (1985), a loaded implant is consid-  ered osseointegrated if the average surface contact with bone  is a minimum of 50% [7]. Initially, the strength of the inter-  face (initial stability) between bone and implant is high due  to mechanical stability; however, it decreases over the next    few weeks due to bone remodeling and then increases again  due to new bone formation (secondary stability). The stability  also depends on biophysical stimulation and the healing  time. To clinically evaluate osseointegration mobility tests,  standardized radiographs and Resonance Frequency Analysis  (RFA) are used [6].    There are many factors that influence the formation and  maintenance of bone at the implant surface [3, 6].    1. Biocompatibility of the implant material - Commercially  pure titanium (CpTi) is widely used as an implant mate-  rial as it is highly biocompatible, it has good resistance to  corrosion and no toxicity on macrophages or fibroblasts  and lacks inflammatory response in peri-implant tissues,  and it is composed of an oxide layer and has the ability to  repair itself by re-oxidation when damaged. Alloys of  titanium such as Ti-6Al-4 V (Aluminum 6% and  Vanadium 4%) and other Aluminum and Vanadium-free  alloys of Titanium have been popularly used. Currently, a  Ti-Zr alloy (Titanium 83-87% and Zirconium 13-17%)  has been introduced, which has mechanical properties  superior to those of CpTi and Ti-6A1-4 V [8].   2. Implant geometry - The shape of the implant determines  the surface area available for stress transfer and the initial  stability of the implant. Implants were previously available  as cylinders, but currently, most implants come in screw-  shaped (threaded) designs. Threaded implants with a circu-  lar cross section provide easy surgical placement and  provide a greater functional surface area. These implants  provide initial rigid fixation and limit micromovement dur-  ing wound healing. The shape of the thread alters the force  transmitted to the bone; it can be square, V, or reverse but-  tress shaped. The thread depth increases the surface area of  the implant. Length of the implant contributes to the over-  all surface area. Increasing the length within limits  increases the bone to implant contact for an implant, which  is essential for osseointegration. Shorter implants are rec-  ommended today only with strict selection criteria and  preferably work well only when splinted with other  implants. Considering the width of an implant, although a  wider implant increases the surface area for osseointegra-  tion, width depends on factors related to the surgical site.  Overall, the shorter and smaller diameter implants have  lower survival rates than their longer or wider counterparts.  Longer implants have been suggested to provide greater  stability under lateral loading conditions [9].   3. Surface characteristics —With exposure to air, Ti and its  alloys form an oxide layer on the surface (TiO2). The oxide    layer protects against corrosion and also helps in calcium  and phosphate ion exchange at the surface. Surfaces were  modified to increase microroughness and hence the sur-  face area for osseointegration. The additive processes are  Ti plasma spraying, hydroxyapatite coating, discrete crys-  talline deposition (DCD), and electrochemical anodiza-  tion (to increase the TiO, layer). These processes increased  the surface area for bone contact with the implant surface,  which increases the osseointegration. Subtractive pro-  cesses to increase microroughness were also utilized in  several implants to increase the microroughness, which  also contributed to better osseointegration. Sandblasting,  acid etching, and laser modification are some of the sub-  tractive processes. Sandblasting produces a macrotexture,  which is converted to a microtexture by acid etching. This  surface promotes greater osseous contact at earlier time  points compared to plasma-sprayed coated implants.  Titanium surfaces were treated with fluoride, and this  roughened the surface and demonstrated better bone  anchorage, as compared to unmodified titanium surfaces  [10]. Research is currently oriented toward making biomi-  metic implant surfaces that shorten healing times and pro-  vide better bone to implant contact [11].   4. Systemic factors — Irradiation of the region, osteoporosis,  smoking, and diabetes although not absolute contraindi-  cations for implant placement can interfere with the nor-  mal healing process and osseointegration. Heavy smoking  results in significantly lower success rates with oral  implants [12]. The local site anatomy such as the amount  of residual ridge for successful implant placement can  also affect the outcome [13].   5. Surgical technique — The extent of tissue manipulation,  thermal irritation by use of rotary instruments, and proto-  cols for a surgical procedure can affect the outcome of  osseointegration [14].   6. Occlusal load — During the initial healing phase, the  absence of micromotion is critical for implant osseointe-  gration. Based on the primary stability achieved, different  protocols for loading are selected. The amount of force and  timing of loading are critical for osseointegration [15].    Figure 18.2a, b, and c show the differences between implants  and tooth.   Implant prosthetics provide highly esthetic results that  mimic the natural tooth; however, certain critical differences  in the structure of the peri-implant tissues and periodontal  structures exist. The lack of a periodontal ligament is the  most striking difference; this absence means that the connec-    Fig. 18.2 (a, b, and c) show diagrammatic representation of the biological differences between an implant and a tooth in longitudinal section    tion between the implant and the surrounding bone is not as  resilient as that around the tooth. Implants, unlike teeth, do  not intrude or migrate to compensate for premature contacts,  and hence, the repercussions of occlusal disharmony can be  detrimental. Implants lack proprioception and reflex func-  tion due to the absence of the periodontal ligament. This is  critical when implant-supported prosthesis opposes each  other. Implants do not supraerupt with time and hence lead to  occlusal disharmonies when used as replacements for young  and growing individuals. Hence, any form of overload on an  implant causes fracture in the prosthesis, the implant struc-  ture, or bone loss surrounding the implant.    (a) Based on the type of material:  (i) Pure titanium and titanium alloys:   Commercially pure titanium(CpTi) was the  material of choice due to its high biocompatibility  and resistance to corrosion. CpTi is available in  Grades I to IV; however, to improve the mechanical  properties, alloys of titanium such as Ti-6Al-4 V  have been used. Several alloys with Ti, such as  Ti-Au, Ti-In, Ti-Sn, Ti-Pb, Ti-Cu, and Ti-Nb, have  been tested. A Ti-Zr alloy (Titanium 83-87% and  Zirconium 13-17%) is presently very popular as it  has mechanical properties superior to those of the  previously used alloys as well as high corrosion  resistance.   These implants are made from the oxide form of  Zirconia (ZnO,) and are “ceramic” implants that  have high biocompatibility and ability to osseointe-  grate. In addition to the high mechanical properties,  they were introduced especially for esthetic areas  and in patients who maybe potentially allergic to  titanium. The drawback of these implants is that  most of the designs are one piece and only a few  systems have two-piece implants. The idea of zirco-  nia implants seems to be potential; however, no  long-term evidence for its success exists at this time.   Threads in screw-type implants increase the sur-  face area for osseointegration. Threads help in sta-  bilization by improving bone to implant contact  and in stress distribution. There are several differ-  ences in thread shape, thickness, pitch, thread-face  angle, etc. based on the manufacturers. These are    the most widely used and documented form of  implants.  (ii) Cylindrical and tapered implants:   Based on the shape of the implant body, implants  are considered cylindrical (with parallel walls) or  tapered. When the endosseous part of a cylindrical  implant narrows in diameter toward the apex, an  implant is considered tapered. The taper can be in  the cervical, middle, or apical parts only or continu-  ously taper from the cervical to the apex. Tapered  implants were introduced to improve initial stabil-  ity in less dense bone.   When a smaller-diameter abutment is used on a  larger-diameter implant collar, the implant-  abutment junction shifts inward toward the central  axis of the implant. This is considered to be a major  factor in limiting crestal bone resorption especially  in esthetic sites.   Tissue-level implants have a butt joint transition  from the smooth collar to the rough portion, and  this transition zone is placed almost level with the  bony crest. This design is generally used for non-  submerged healing; here, the implant-abutment  microgap is away from the bony tissues. Bone-level  implants have minimal/no smooth collar and are  completely microrough, and they are inserted  almost level with the bone. This is meant for sub-  merged healing, and here, the implant-abutment  microgap is adjacent to the bone crest. In these  implants, platform switch is used to limit crestal  bone resorption.   These are the minimally rough implant surfaces  made of turned CpTi, which were not further  treated. These were used earlier and are also well  documented. However, with a need to increase the  surface area for bone attachment especially in less  dense bone and to reduce time for osseointegration,  these surfaces were modified. Smooth surfaces had  an advantage of reduced attachment of plaque  biofilms.   The smooth surfaces of the implants were  altered to a textured surface to increase the surface  area for osseointegration. They were classified as  macro-, micro-, and nano-sized topologies based  on the scale of roughness [17, 18].  Macrotopographic profiles of dental implants had    a surface roughness in the range of millimeters to  microns. This roughness was directly related to  geometry of the implant, threaded screw, and mac-  roporous surface treatment. Microrough topogra-  phies were in the range of | and 10 pm. A profile  roughness average of 1—2 «1m is optimal for osseo-  integration [19]. The surfaces were altered by dif-  ferent processes. Additive processes resulted in  these popular types—sintered porous surfaces,  titanium plasma sprayed, and hydroxyapatite  plasma sprayed. Subtractive processes also cre-  ated a rough texture, and they were sandblasting,  acid etching, and laser alteration. Rough surfaces  were demonstrated to have better bone to implant  contact, which resulted in better osseointegration  [20, 21]. Over the years, nanotopographies have  been explored. Compaction of nanoparticles (such  as titanium dioxide), molecular self-assembly  method, and acid/alkali treatments or peroxidation  for nanoparticle deposition have been advocated  to increase nanoroughness.  Hydrophobic and hydrophilic implant surfaces [22]:  Initially, modification of implant surfaces con-  centrated on surface topography, and hence, the sur-  faces were hydrophobic. It was observed that porous  devices should have a hydrophilic surface to induce  the adsorption of bodily fluids into small pores and  cavities of the structure. The surface chemistry of  implants was altered to allow for hydrophilicity, and  these surfaces have enhanced bone apposition dur-  ing the initial phases of healing [23].  (d) Based on length (Al-Johany 2017) [24].  (i) Extra-short: 6 mm in length or less.   Gi) Short: From more than 6 mm to less than 10 mm.   Although traditionally, the concept was to get  implants “as long as possible” for good osseointe-  gration, the current trend with improved surfaces is  “as long as needed”. The introduction of shorter  implants is to reduce the invasiveness and reduce  morbidity.   (e) Based on diameter (Al-Johany 2017) [24].  (i) Extra narrow: Less than 3.0 mm.  (ii) Narrow: From 3.0 mm to less than 3.75 mm.  (iii) Standard: From 3.75 mm to less than 5 mm.  (iv) Wide: 5.0 mm or more.   Earlier, implants with diameters as wide as the  tooth being replaced were used. Changing concepts  of jumping gap, preserving the buccal cortical plate,  and optimal 3-dimensional position coupled with  improved surfaces encouraged slightly narrow diam-    Box 18.1 Types of Implants  Implants can be classified as follows:    (a) Implant Material  (i) Titanium and titanium alloys  (ii) Zirconia  (b) Shape:  (i) Screw type implants  (ii) Cylindrical, apically tapered,  tapered  (iii) Platform-switch implants  (iv) Bone level vs. tissue level implants  (c) Implant surface  (i) Machined (Branemark surface)  (ii) Textured/rough surfaces  (iii) Hydrophobic/Hydrophilic surfaces  (d) Implant length  (e) Implant diameter    eters as compared to previous trends. Extra-narrow  and narrow-diameter implants are used in deficient  sites to minimize invasiveness and morbidity.    Before implant treatment, a careful analysis should be con-  ducted. This includes patient’s current health status and med-  ications and details of past medical history and medical  treatments.   Patients should be questioned about parafunctional hab-  its, oral hygiene, and personal habits such as tobacco, alco-  hol, and drugs. The compliance, motivation, attitude,  understanding, and expectations of the patient are important  for optimal treatment outcome.   Clinical examination should include extra-oral examina-  tion, i.e., lip line, lip competence, and temporomandibular  joint. Intraoral assessment should include assessment of the  edentulous space, occlusion, status of adjacent and opposing  teeth, overall periodontal status, presence of other implants  and restorations, shape of the teeth, gingival biotype, and any  other local factor that may impact the success of the  treatment.   Diagnostic study models and intraoral clinical photo-  graphs are essential for documentation as well as for the fur-  ther assessment of spatial and occlusal relationships.    Figure a and b show examples of two-dimensional and  3-dimensional examination of the maxillary sinus.   Radiographic examination should be done in the evalua-  tion phase to determine the status and anatomy of the  underlying bone, if implant placement is possible and if any  other surgical procedures are required before implant place-  ment. A 2-dimensional radiograph of the area is desired;  however, this is insufficient to provide a detailed 3-dimen-  sional assessment of the site. Hence, the radiograph of choice  is the Cone Beam Computerized Tomography (CBCT) as it  provides a detailed three-dimensional analysis of the edentu-  lous area along with the neighboring anatomical structures.  With the software for CBCT, it is possible to measure accu-  rately the dimension of the site and distances from critical  structures and accurately plan which implant dimension  would be appropriate. CBCT imaging also gives us informa-  tion on which sites require augmentation and if so the loca-  tion and extent required.    For the site of implant placement, the available space should  be evaluated in three dimensions, i.e., mesiodistal, buccolin-    ; (a and b) show examples of two-dimensional and 3-dimensional examination of an implant placed with sinus floor elevation    gual, and apicocoronal dimensions. A graduated periodontal  probe can be used for clinical measurements; however, this  information is best recorded from imaging techniques such  as CBCT. While evaluating the available space, factors such  as proximity to adjacent anatomical structures such as maxil-  lary sinus, mandibular nerve, nasal floor, adjacent tooth  roots, etc. should be considered.   The minimal space required for an implant depends on  the size of the implant to be used (in terms of length and  diameter), whether the implant is placed adjacent to two nat-  ural teeth or adjacent to an implant and the apicocoronal dis-  tance in the bone.    1. Implant adjacent to a natural tooth: Buser et al. (2004)  suggested a concept for correct 3-dimensional implant  placement [25]. They designated zones called as com-  fort zones (which is the ideal position for an implant)  and danger zones (in which implants should not be  placed). This was defined in three directions mesiodis-  tally, coronoapically, and orofacially. (Figure a, b,  and c show diagrammatic representation of the correct  positioning of implants in a 3-dimensional manner). The  ideal mesiodistal distance between a natural tooth and  the shoulder of an implant is 1.5 mm [25]. The zone up  to 1-1.5 mm from the adjacent teeth on either side was  the danger zone. Between the danger zone was the com-  fort zone that is safe for implant placement [25]. For    If placed too close to the adjacent teeth, it causes bone  loss. In the orofacial dimension, the implant shoulder is  positioned palatal to the incisal edge of the future resto-    example, if an implant of 4.1 mm in diameter is placed    ration (or 1 mm palatal to the point of emergence of the    Fig. 18.4 (a, b, and ec) diagrammatic representation of ideal placement of a single implant in green shadow and unideal positions that could lead    to complications (in red shadow). (a) ideal coronoapical position, (b) ideal mesiodistal position, and (c) ideal orofacial position    adjacent teeth). The oral aspect has a danger zone as  well, indicating that an implant should not be placed too  far orally to prevent the use of a ridge lap restoration.  Too far facially will result in increased mucosal reces-  sion. In the apicocoronal direction, the apex of the  implant should be at least 1-2 mm away from any ana-  tomical structure such as nerve, sinus, or tooth roots.  Also, in the shoulder of the future implant should be at  least 1 mm apical to the cementoenamel junction of the  adjacent teeth to allow for a proper emergence profile  [25]. Placing an implant too deep will result in too  much countersinking, difficult handling, and facial  mucosal recession. Placing an implant too superficially  will cause the metal margin to be visible and improper  emergence profile. In addition to this, the ideal facial  bone thickness should be 2 mm [26] and the lingual  bone thickness should be 1.5 mm. Hence, for a 4.1 mm  implant, minimum orofacial distance should be approx-  imately 7.5 mm. Also, to prevent the appearance of  black triangles, the apicocoronal distance from the  interdental contact point to the crest of bone should not  exceed 5 mm. (Figure 18.5a shows diagrammatic repre-    sentation of the distance between interdental contact  point and the crest of bone, for adequate papilla  preservation).    between the implants should be at least 3 mm [25, 26].  This is critical to allow adequate interimplant bone and  hence the formation of a soft tissue papilla overlying the  bone. The other requisites for mesiodistal, orofacial, and  apicocoronal dimensions, as previously mentioned, apply  in addition. (Figure 18.5b shows diagrammatic represen-  tation of the distance between interdental contact point  and the crest of bone, for adequate papilla preservation).  When the space for an implant of a particular diameter  is less than ideal, a decision should be made either to aug-  ment the site with bone or to choose an implant of smaller  diameter. However, this decision requires clinical exper-  tise as augmentation procedures are technique sensitive  and using smaller diameter implants depends on evalua-  tion of the occlusal forces in the area. The interocclusal  distance also needs to be evaluated prior to implant place-  ment as it determines the choice of prosthetic rehabilita-  tion of the implant. If the interocclusal distance is reduced,    Critical Dimension : H < 5mm  @©Association of Oral and Maxillofacial Surgeons of India    Fig. 18.5 (a and b) diagrammatic representation of the critical dimen-  sions in implant placement in relation to interdental papilla. (a) The  height (H) of the interdental contact from the crest of the interdental  alveolar bone should not be more than 5 mm for obtaining adequate    the choice would be to use a screw-retained prosthesis  over a cement-retained one. Screw-retained prosthesis,  however, is the more preferred technique due to ease in  retrievability and cleansability.   The amount of keratinized tissue in the site should also  be evaluated before surgery as this determines the loca-  tion of the incision. Ideally, a band of at least 2 mm (mini-  mum | mm) keratinized tissue should surround the  implant, and this is critical to the long-term success of the  implant. If this is not achievable, procedures to augment  the keratinized mucosa should be planned. Keratinized  mucosa is necessary as it provides a physical barrier to  oral plaque and to the forces of mastication as compared  to nonkeratinized mucosa [27].    The International Team for Implantology (ITI) proposed a  classification of sites for implant placement based on the  analysis of several factors [28].   Based on these factors, sites for implant surgery could be  classified as straightforward (S), advanced (A), and complex (C).    interdental papillary morphology. (b) The interimplant distance (D)  should be at least 3 mm for obtaining adequate interdental papillary  morphology    This provides the clinician an assessment of the site for  implant placement before the surgery is planned and is based  on the level of expertise of the clinician who can either treat  or refer to a specialist.    1. Esthetic or nonesthetic site: Any case in the esthetic zone  or has an esthetic risk should be considered as advanced  or complex.   2. Complexity of the process: The level of complexity can  be assessed by considering the number of steps and the  number of areas in which an acceptable outcome has to be  achieved.   3. Risk of complications: The SAC Classification can be  used to identify and quantify risks for complications. This  allows pretreatment planning to control and minimize  risks.    for a case type is independent of the clinician’s skill and  competence. A Straightforward case is an uncomplicated    procedure, and a Complex case is the one that is difficult  to manage.   2. Compromised patient’s health: Patients with risk factors  such as smoking, diabetes, irradiated bone, history of  periodontal disease, poor oral hygiene, and bruxism need  to be monitored as they have a higher risk for  complications.   3. Growth considerations: Implants placed in the jaws of  growing individuals are modifying factors as they present  esthetic and functional issues.   4. Iatrogenic factors: Suboptimal planning and treatment  outcomes increase the difficulty in the implant treatment  phase. For example, incorrect three-dimensional implant  placement will complicate the restorative process.    Tables 18.1, 18.2, and 18.3 show the esthetic, surgical,  and restorative modifying factors to be considered during  implant treatment planning and execution.    Table 18.1 The esthetic modifying factors are determined by the  Esthetic Risk Assessment (ERA)    Low Medium High  Medical status Healthy and - Reduced  co-operative patient immune  with an intact system  immune system.  Patients’ Low Medium High  esthetic  expectation  Smoking habit Nonsmoker Light smoker Heavy  (<10 cigs/day) smoker (>10  cigs/day)  Lip line Low Medium High  Shape of tooth Rectangular Triangular  crowns  Gingival Low scalloped and Medium High  biotype thick scalloped and scalloped  medium thick and thin  Bone anatomy Alveolar crest Horizontal Vertical bone  of alveolar crest without bone bone deficiency  deficiency deficiency  Bone level at <5mmtocontact 5.5to6.5mm >7mmto  adjacent teeth _ point to contact contact point  point  Soft tissue Intact soft tissue Soft tissue  anatomy defects  Width of 1 tooth (=>7 mm) 1 tooth 2 teeth or  edentulous span (<7 mm) more  Restorative Virgin Restored  status of  neighboring  teeth  Infection at None Chronic Acute    Adapted with permission from Dawson A, Chen S, Buser D, Cordaro L,  Martin W, Belser U. The SAC Classification in Implant Dentistry.  Editors: Dawson A, Chen S. Quintessence Publishing Co. Ltd. 2009    The above-mentioned modifiers have to be considered  for every implant case during the assessment and planning  phase of treatment. Risks can be identified prior to treat-  ment, thus minimizing complications. To classify as  Straightforward, Advanced, or Complex for a specific case,  the specific features of the case can be matched with the  descriptions in the tables. The level that best matches the  factors of the individual case will provide the SAC  Classification for that case.   The final treatment plan including additional surgical pro-  cedures (if required) should be formulated after accurate  diagnosis and consideration of the patient’s systemic and  local factors, bearing in mind the requirements of the patient.    Adapted with permission from Dawson A, Chen S, Buser D, Cordaro L,  Martin W, Belser U. The SAC Classification in Implant Dentistry.  Editors: Dawson A, Chen S. Quintessence Publishing Co. Ltd. 2009    The degree to which the implant  prosthesis is involved in the patient’s  occlusal scheme   Risk of complication to the restoration,  but not to implant survival    Refers to the distance from the proposed  implant restorative margin to the  opposing occlusion    Refers to whether there is sufficient tissue  volume to support the final restoration, or  some prosthetic replacement of soft  tissues will be necessary    Provisional restorations will be needed to  develop esthetics and soft tissue transition  zones   To date, immediate restoration and  loading procedures are lacking scientific  documentation   Anticipated maintenance needs based on  patient presentation and the planned  prosthesis    Some reduction in  size or number of  teeth will be  necessary    Restorative margin  <3 mm apical to  mucosal crest  Porcelain fused to  metal    Adjunctive therapy will be  necessary to gain sufficient  space for the planned  restoration   Prosthetic replacement of  soft tissue will be needed  for esthetics or phonetics  Present    Adapted with permission from Dawson A, Chen S, Buser D, Cordaro L, Martin W, Belser U. The SAC Classification in Implant Dentistry. Editors:  Dawson A, Chen S. Quintessence Publishing Co. Ltd. 2009    Implants can be used as replacement options for all kinds of  edentulous situations varying from single tooth gaps to com-  pletely edentulous jaws (Figure 18.6 shows an example  where an implant has been used for the restoration of single  tooth, and 7b shows an example where implants have been  used for the replacement of the edentulous upper and lower  jaws). The treatment plan varies in complexity as the number  of teeth replacements increases, if it is an esthetic site or not    and if the opposing dentition is implant-supported or not and  depending on the occlusal load. As few as possible but as  many as needed should be the key when placing implants.  The selection of the size of the implant (length and width)  and the number of implants especially in areas of poor bone  quality is important for providing the correct solution.   For large edentulous spans, it is preferable to use as many  implants as required, to support the occlusal forces in that  area. Cantilever prosthesis on implants has to be used with  discretion and is limited to areas of low occlusal demand. It  is not preferable to splint implant with natural teeth as    Fig. 18.6 (a) shows an example where an implant has been used for  the restoration of single tooth, and (b) shows an example where  implants have been used for the replacement of the edentulous upper  and lower jaws    implants cannot intrude with force like natural teeth. Long-  span bridges on implants are not advisable in soft bone, e.g.,  in the completely edentulous maxilla, a fixed prosthesis can  be given on six implants, while in the mandible, the same can  be achieved with only four implants. For removable prosthe-  sis, in an edentulous maxilla, four to six are sufficient, while  in the edentulous mandible, the similar prosthetic solution  can be achieved with two to four implants. There are several  concepts of implant replacement for long edentulous spans    and several designs of implants indicated for specific types  of sites; however, the details of these are beyond the scope of  this chapter.    Studies in beagle dog revealed that postextraction, the bun-  dle bone resorbs as the blood supply to this bone is compro-  mised due to tooth extraction [29, 30]. This results in vertical  bone loss in both facial and lingual walls of the socket, but it  is more pronounced on the facial aspect as most often it is  thinner in width than the lingual wall [30]. In human studies,  ridge width reduction of up to 50% occurred during the first  year after tooth loss in premolar and molar sites, and two-  thirds of the total change took place within the first 3 months  following extraction [31]. Dimensional alterations occurred  in both height and width, with approximately 2.6-4.5 mm in  width and 0.4—-3.9 mm in height being lost in the healed  sockets [32]. Histologically, the density of vascular struc-  tures and macrophages reduced from 2 to 4 weeks, the osteo-  clastic activity slowly decreased over a 4-week period, and  osteoblasts peaked at 6-8 weeks remaining almost stable  thereafter [33]. Thin facial walls seem to be prone for resorp-  tion, and sites with facial bone wall thickness of 1 mm or less  had vertical bone loss of 7.5 mm (62%) of the original bone  height after an 8 week healing period. Patients with thick  wall phenotype, having facial bone wall thickness of more  than | mm, had only about 1.1 mm (9%) vertical bone loss  [34]. Also, for single extraction sites, the dimensional altera-  tion occurred mainly in the central mid-facial area of the  socket wall, while the proximal areas that had viable peri-  odontal ligament of the adjacent teeth remained nearly  unchanged after flapless tooth extraction at 8 weeks of heal-  ing [35]. With this pattern of resorption, a thin wall pheno-  type will develop a two-wall defect, while a thick-wall  phenotype will result in a three-wall defect after initial  remodeling [34]. Thus, the evaluation of facial wall thick-  ness is critical to predict the future of bone loss prior to  extraction [13]. With the above findings related to the pattern  of bone remodeling and the timing of the cellular activity, in  thin bone wall phenotypes, it is recommended to allow the  initial postextraction remodeling to take place before initiat-  ing regenerative procedures. An early implant placement  would be recommended for thin bone phenotypes. Immediate  implant placement would be recommended only for thick  wall phenotypes and thick gingival biotypes where minimal  remodeling would be expected.   The soft tissue thickness in maxillary anterior teeth is thin  in most patients, ranging from 0.5 mm to 1 mm. This soft tis-    sue thickness has not shown significant correlation to the  underlying facial bone wall thickness [36]. For single extrac-  tion sites, 50% of the soft tissue change occurs within the first  2 weeks postextraction. The increase in soft tissue thickness  significantly depends on the underlying bone dimensions. In  thick wall phenotypes, the soft tissue dimensions do not sig-  nificantly change. In these defects, the alveolus acts as a self-  contained bony defect and favors the growth of bone-forming  cells from the adjacent socket walls. In thin wall phenotypes,  the facial bone wall resorbs rapidly and the highly prolifera-  tive soft tissue occupies its position. There is a sevenfold  increase in soft tissue occupying the crestal area of the socket  defect, and this is termed as spontaneous soft tissue thickening  [13]. The tissue formed is highly vascularized granulation tis-  sue with fibroblasts migrating into it, some of which differen-  tiate into myofibroblasts that are involved in the thickening  phenomenon. At 8 weeks, there is a peak in endothelial cell  density, BMP-7, and osteocalcin expression, indicating that  the molecular and cellular mechanisms that regulate new bone  formation also influence the soft tissue thickening. The clini-  cal implications of this soft tissue thickening are that, after an  8 week healing period, the soft tissues are sufficiently thick-  ened and provide increased keratinized tissue in the site that  allows for primary closure favoring bone regeneration. With  this thickened soft tissue, there is no requirement for addi-  tional soft tissue grafts. However, this soft tissue thickening  can mask the underlying bone defect, often misleading the cli-  nician while selecting the appropriate treatment protocol [37].    Implant placement can be classified based on the timing of  implant placement. According to the ITI Consensus  Conferences in 2003 and 2008, it is classified as Type 1,  Type 2, Type 3, and Type 4 implant placement [38].    Type 1: When placed immediately after tooth extrac-  tion, it is called immediate implant placement.   Type 2: When placed 4-8 weeks after tooth extraction,  itis an early implant placement with only soft tissue  healing   Type 3: When placed 12-16 weeks after tooth extrac-  tion, it is an early implant healing with partial bone  healing   Type 4: When placed after 6 months after tooth extrac-  tion, there is complete bone healing, and this is  called delayed implant placement.    The choice of timing of implant placement depends on  several factors. The four options are available to the clini-  cian, who can select the option based on the following crite-  ria, provided that they have the required clinical expertise.    ¢ Immediate implant placement (type I) is recommended to  be performed only by experienced clinicians in sites that  have ideal anatomic conditions, such as:   (i) a completely intact, thick wall phenotype (i.e.,  >I1mm) facial bone wall at the extraction site   (iv) adequate volume of bone apical and palatal of the  extraction site to allow sufficient primary stability of  the implant while placing it in the correct  3-dimensional position.   ¢ Type 2 placement is recommended when the above ideal  conditions are not met.   (i) In situations where there is inadequate keratinized  tissue, this technique allows an additional 3-5 mm of  tissue as the tissues heal spontaneously.   In sites where there is a thin facial bone, the bundle   ¢ Type 3 implant placement is recommended in cases where  either primary stability cannot be achieved even after   ¢ Type 4 implant placement is often not a preferred treat-  ment by the patient. However, the indications for this type  of implant placement are determined by certain patient-  related factors or site-specific factors. Patient related fac-  tors include.   (i) patients with systemic conditions that require treat-  ment to be deferred, e.g., pregnant patients,   (ii) adolescent patients who are too young to receive  implants and require the treatment to be deferred,  and   (iii) patients who are unable to make an early appoint-  ment due to personal reasons.   (b) Impacted or ankylosed teeth that cause a lot of  bone removal in the apical aspect of the site. In  all these cases, it is recommended that socket  grafting with a low substitution filler is used to  reduce ridge alterations and ridge atrophy. The  crestal bone resorption is inevitable; however,  the use of socket grafting minimizes the need for  ridge augmentation at a later date.    When an implant is placed, the operator can choose to either  submerge the implant (completely enclose it within the heal-  ing tissues) or keep it nonsubmerged (implant is visible  through the healing soft tissue). (Figure 18.7 shows diagram-  matic representation of submerged and nonsubmerged  healing).   In the nonsubmerged/one-stage approach, the healing  cap/abutment of the implant emerges through the mucosal  tissues at the time of flap closure after implant placement.  Nonsubmerged implants can be one-piece or two-piece  implants. In one-piece implants, there is no micromovement    and no microgap between the implant and the abutment. In  the two-piece nonsubmerged implants, there is no need for a  second surgical procedure to expose the implant for prosthet-  ics; however, the potential of the microgap between the two  components exists. This technique is generally preferred for  standard implant placement procedures where there is no  need to augment the site.   In the submerged/two-stage approach, the healing cap/  cover screw is completely covered with the soft tissue flap  after implant placement surgery. The implants are allowed to  osseointegrate in a closed environment without loading or  any form of micromovement, for a period of time. The sub-  merged protocol is used for implant placement with simulta-  neous bone augmentation. Following this healing period, the  implant is surgically exposed to place the abutment. Both  these techniques are well accepted and can be selected based  on the treatment plan.    As mentioned before, the most important step before implant  surgery is the analysis of the general patient factors and then  the local edentulous site factors. Depending on whether it is  an implant replacement for a single tooth, multiple teeth, or  a completely edentulous ridge, the planning differs. The    treatment protocol also differs depending on whether it is an  esthetic site or not. Single tooth replacements in a nones-  thetic site are simpler as compared to multiple teeth replace-  ments in an esthetic site.    1. Local anesthesia: the area of surgery including at least  two teeth mesial and distal should be well-anesthetized.   2. Incision: a scalpel blade no 15 is used to make a horizon-  tal paracrestal incision. This bisects the existing zone of  keratinized mucosa with at least 2 mm on the buccal  aspect of the future implant. The incision extends to one  tooth mesially and distally with a papilla sparing incision.  If required, a vertical release incision can be given on the  distal aspect to create a triangular flap.   3. Flap elevation: A full thickness mucoperiosteal flap is  elevated on the buccal and on the lingual aspect. A retrac-  tion suture can be placed in the buccal and lingual flaps if  required. The crestal bone should be exposed sufficiently  so as to get visible access to the implant site as well to  check the palatal and buccal curvature of the ridge.   4. Flattening of the ridge: A large round rose bur is used to  flatten the ridge, thus removing any bony slopes in the  crestal area. This also allows removal of the narrower por-  tions from the crest of the ridge; however, extensive  removal in short ridges should be done judiciously.   5. Drilling of the osteotomy: all drilling should be done  along with copious amounts of cold saline irrigation with  the speed as specified by the manufacture for each par-  ticular bur/drill (generally in the range of 800-1500 rpm).  It is important to keep an eye for the correct positioning  and the neighboring anatomic structures during each  stage of drilling.   (a) Initially, a small diamond bur is used to mark the site.  The mark created corresponds to the center of the  osteotomy and should be in the correct mesiodistal  and buccolingual position. This bur is used to make a  hole of 1-2 mm deep to create a start point for the  pilot drill.   The pilot drill is the first twist drill used to create the   of the osteotomy should be slightly more than the  implant so that the implant can be placed slightly sub-  crestal (to compensate for future crestal bone resorp-  tion). Also, the shoulder of the future implant should  be 1 mm apical to the cementoenamel junction of the  adjacent teeth in esthetic areas to allow for a proper  emergence profile. While drilling, the correct axis    should be maintained. The drills should be repeatedly  pumped in and out of the osteotomy to expose the bone  debris to the water coolants for clearing. If multiple  implants are to be placed, a guide pin is used in the first  osteotomy to align the second implant before com-  mencing the second osteotomy preparation.  Subsequent drills are used in the same way as the  pilot drill to enlarge the osteotomy to the desired  depth.   Profile drills or countersink drills are used between  the sequential drills to widen the crestal part of the  osteotomy to allow the next drill into the osteotomy.  The countersink drill also flares the preparation to  allow the placement of the cover screw over the  implant without any bony interference.   Bone tapping is an optional step that is required only  in very dense bone. This is done at very slow speeds  (20-40 rpm) without water irrigation.    at slow speeds (18-25 rpm) or by hand using a torque  wrench. Implant insertion should follow the same path of  insertion as that of the osteotomy. For multiple implants,  guide pins serve as a direction indicator to obtain parallel-  ism. Care is taken to insert the implant such that the  microrough surface of the implant is 1-1.5 mm sub-  crestal. This prevents exposure of the rough surface of the  implant to the environment during the eventual crestal  bone remodeling. The implant should also be placed such  that the shoulder of the implant should be at least 3-4 mm  apical to the cementoenamel junction of the adjacent  teeth. It is also important that primary stability is achieved  at placement and the average insertion torque should be  35 Ncm?; however, ISQ values are a more accurate record-  ing as they can be measured from time to time and a com-  parison can be obtained unlike insertion torque, which is  only a one-time measurement. Once the desired position  and stability are achieved, the cover screw (for submerged  healing)/healing abutment (nonsubmerged healing)  should be fitted over.    mated so as to provide tension-free closure. If required, a  periosteal release incision can be done. If a submerged  healing is planned, the flap should be completely closed  over the implant by primary closure. If a nonsubmerged  healing is intended, then the flap is closed around the  healing abutment. Although any technique of suturing is  acceptable, it is preferable that for long horizontal spaces,  horizontal mattress sutures along with interrupted sutures    are placed in 4-0 or 5-0 nonresorbable sutures. Suturing  of vertical incisions and papillae is generally done with  5-0 or 6-0 nonresorbable sutures.   8. Postoperative care: Simple implant surgery in a healthy  patient does not require antibiotic coverage; however,  if the patient has any systemic complications or at risk  of infection, it is advisable to put the patient on postop-  erative antibiotic coverage. Analgesics are recom-  mended for the first few days after surgery. Patient is  given routine postsurgical instructions such as use of  ice packs for the first 24 h, soft diet, no vigorous rins-  ing, no brushing on the surgical site, no tobacco smok-  ing, and no vigorous exercise. Provisional replacements  should not transmit direct forces to the underlying  implant and should be adequately relieved from the  surgical site, particularly in the early healing period  (4-8 weeks). Patient is recalled on the second postsur-  gical day and after that | week postoperatively to check  for healing.   9. Prosthetic phase: depending on the choice of timing to  load the implant, the reopening phase can be planned. For  nonsubmerged implants, often, no second surgery is  required as the healing abutment is exposed. For sub-  merged implants, the healing cap/abutment can be  exposed by a small surgical procedure and a taller healing  abutment can be inserted so as to allow the mucosal tissue  to heal around and create an emergence profile.    (Figure 18.8 shows an example of the surgical phase of  single implant placement)    An implant loading protocol is the time period between  implant placement and the attachment of the prosthesis. The  loading protocols have changed over the years, and the ITI  Consensus Conferences in 2003, 2008, and 2013 had slight  variations in defining them. The current definition as per the  ITI Consensus Conference 2018 is as follows [39]:    (a) Immediate loading: Loading of dental implants  earlier than 1 week after implant placement. This  can be done with either a provisional prosthesis or  a final prosthesis. The provisional prosthesis is  used to reshape the peri-implant soft tissues for  better esthetic outcomes, modify the occlusion, or  evaluate a planned implant prosthesis. A final  prosthesis can be directly given in cases with low  esthetic risk and in areas of stable occlusion. This  protocol significantly reduces the treatment time,  and both soft tissue and bony healing occurs under  functional loading.   Early loading: Loading of dental implants between  1 week and 2 months after implant placement. In  this treatment approach, functional forces are  exerted on the implants during the later stages of  bone healing. Soft tissues are still healing, and by  two months, they are almost completely healed.  Here also, the time between placement and load-  ing is reduced.   Conventional loading: Loading of dental implants  more than 2 months after implant placement [40,  41]. This allows for a complete healing of bone  and peri-implant soft tissue and requires a longer  treatment time between implant placement and  loading. This protocol is selected in cases when  there are medical or risk factors, low implant sta-  bility at surgery, and extensive augmentation in the  implant site and with short or narrow diameter  implants.    Patient-related factors such as medical and systemic risk fac-  tors, surgical site factors (augmented site), and implant stability  as assessed by insertion torque (20-50 Nem’) and resonance  frequency analysis (>55 ISQ) are determinants for selecting the  loading protocol. Implant design and characteristics also affect  the loading protocol, surface modification of implants has added  to faster healing rates of bone around implants, and hence, the  healing period before loading has reduced [23]. Hence, selec-  tion of a correct loading protocol is case specific.    Fig. 18.8 These series of figures show steps in implant placement with  restoration of a single tooth edentulous space. (aa) Preoperative facial  view of edentulous space. (ab) Preoperative occlusal view of edentu-  lous space. (ac) Preoperative master cast with surgical splint. (b)  Incision and reflection of mucoperiosteal flap. (ca) Initial drilling. (cb)  Checking for ideal placement of initial drill with surgical guide, which  would lead to prosthodontically driven implant placement and a favor-    able emergence profile. (ec) Checking for the depth of implant osteot-  omy using a depth gauge. (da) Subsequent drilling to accommodate the  chosen dimension of the implant. (db) Subsequent drilling to accom-  modate the chosen dimension of the implant. (e) Implant insertion. (f)  Placement of healing abutment for transmucosal/ non submerged heal-  ing. (g) Suturing and wound closure    A review of an alternative mode of fixation. Acta Orthop Scand.  1987;58(5):567-77.    8. Osman RB, Swain MV. A critical review of dental implant materi-  als with an emphasis on titanium versus Zirconia. Materials (1996-  1944). 2015;8(3):932-58.  References 9. Vootla NR, Reddy KV. Osseointegration- key factors affecting  its success-an overview. IOSR J Dent Med Sci (IOSR-JDMS).  . oo. . . 2017;16(4):62-8. e-issn: 2279-0853, p-issn: 2279-0861   4 Abraham CM. A brief historical perspective of dental implants, 10. Ellingsen JE, Johansson CB, Wennerberg A, Holmen A. Improved  their pane coatings and treatment. Open Dent J. 2014;8(Suppl retention and bone-to-implant contact with fluoride-modified tita-  1-M2):50-S. nium implants. Int J Oral Maxillofac Implants. 2004;19:659-66.   . Mavrogenis AF, Dimitriou R, Parvizi J, Babis GC. Biology of pies : ; : :    . Stanford CM, Keller JC. The concept of osseointegration and bone  matrix expression. Crit Rev Oral Biol Med. 1991;2(1):83-101.  . Reddy VK. Osseointegration. 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A histo- morphometric study in miniature. J Biomed  Mater Res. 1991;25:889-902.   Wennerberg A. The role of surface roughness for implant incorpo-  ration in Bone. Cells Mater. 1999;9(1):1-19.   Lang NP, Salvi GE, Huynh-Ba G, Ivanovski S, Donos N, Bosshardt  DD. Early osseointegration to hydrophilic and hydrophobic  implant surfaces in humans. Clin Oral Implants Res. 2011  Apr;22(4):349-56.   Buser D, Broggini N, Wieland M, Schenk RK, Denzer AJ, Cochran  DL, Hoffmann B, Lussi A, Steinemann SG. Enhanced bone apposi-  tion to a chemically modified SLA titanium sur- face. J Dent Res.  2004;83(7):529-33.   Al-Johany SS, Al Amri MD, Alsaeed S, Alalola B. Dental  implant length and diameter: a proposed classification scheme. J  Prosthodont. 2017 Apr;26(3):252-60.   Buser D, Martin W, Belser UC. Optimizing esthetics for implant  restorations in the anterior maxilla: anatomic and surgical consider-  ations. Int J Oral Maxillofac Im- plants. 2004;19(suppl):43-61.  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Bone healing  and soft tissue contour changes following single-tooth extrac-  tion: a clinical and radiographic 12-month prospective study. Int J  Periodontics Restorative Dent. 2003;23:3 13-23.   Ten Heggeler JM, Slot DE, Van der Weijden GA. Effect of socket  preservation therapies following tooth extraction in non-molar  regions in humans: a systematic review. Clin Oral Implants Res.  2011;22:779-88.   Trombelli L, Farina R, Marzola A, Bozzi L, Liljenberg B, Lindhe  J. Modeling and remodeling of human extraction sockets. J Clin  Periodontol. 2008 Jul;35(7):630-9.   Chappuis V, Engel O, Reyes M, Shahim K, Nolte LP, Buser  D. Ridge alterations post-extraction in the esthetic zone: a 3D anal-  ysis with CBCT. J Dent Res. 2013;92:195S—201S.   Chen ST, Buser D. Clinical and esthetic outcomes of implants  placed in postextraction sites. Int J Oral Maxillofac Implants.  2009;24(Suppl): 186-217. Review   Chappuis V, Engel O, Shahim K, Reyes M, Katsaros C,  Buser D. Soft tissue alterations in esthetic postextraction  sites: a 3-dimensional analysis. J Dent Res. 2015 Sep;94(9  Suppl):187S—93S.   Morton D, Chen ST, Martin WC, Levine RA, Buser D. Consensus  statements and recommended clinical procedures regarding opti-  mizing esthetic outcomes in implant dentistry. Int J Oral Maxillofac  Implants. 2014;29(Suppl):2 16-20.   Buser D, Chappuis V, Belser U, Chen S. Implant placement post  extraction in esthetic single tooth sites: when immediate, when  early, when late? Periodontology 2000. 2017;73:84—102.   Gallucci GO, Hamilton A, Zhou W, Buser D, Chen S. Implant  placement and loading protocols in partially edentulous patients:  a systematic review. Clin Oral Implants Res. 2018;29(Suppl.  16): 106-34.   Gallucci GO, Benic GI, Eckert SE, Papaspyridakos P, Schimmel  M, Schrott A, Weber HP. Consensus statements and clinical rec-  ommendations for implant loading protocols. Int J Oral Maxillofac  Implants. 2014;29(Suppl):287-90.   Weber HP, Morton D, Gallucci GO, Roccuzzo M, Cordaro L,  Grutter L. Consensus statements and recommended clinical proce-  dures regarding loading protocols. Int J Oral Maxillofac Implants.  2009;24(Suppl):180-3.    Open Access This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.  org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropri-  ate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.    The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in    a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.   Dental implants have been used successfully to rehabilitate  patients with edentulousness. For implant dentistry to be suc-  cessful, the implants have to be placed in an appropriate three-  dimensional manner that supports the prosthesis adequately.  This means that implants have to be placed in a prosthodonti-  cally driven predetermined position. This requirement often  results in a clinical situation where there is a lack of bone vol-  ume to completely embed the implant in an ideal position.   Implants that do not have an adequate amount of bone cov-  ering them in all aspects (at least 1.5 mm bone buccal and lin-  gual to the implant shoulder or about 2 mm in aesthetic zones)  are at high risk for crestal bone loss with concomitant inflam-  mation and infection of the surrounding soft tissues due to  exposure and colonisation of the implant surfaces by bacterial  biofilms [1]. This in turn results in soft-tissue recession, which  leads to further loss of bone and eventually failure of the  implant. Hence, bone augmentation is often necessary to  ensure adequate bony housing around implants [2].   The most commonly used bone-augmentation surgical pro-  cedures are guided bone regeneration (GBR), block bone graft-  ing and maxillary sinus floor elevation (SFE). When deciding  to augment, there are multiple sources of bone-augmentation  materials ranging from autogenous, allogenic, xenogenic and  synthetic materials. A knowledge of these materials is essential  prior to undertaking augmentation procedures. Knowledge of  bone biology and bone physiology is also important.    Electronic Supplementary Material The online version of this chap-  ter (https://doi.org/10.1007/978-98 1-15-1346-6_19) contains supple-  mentary material, which is available to authorized users.    V. V. Kumar (D4!) - A. Thor  Department of Maxillofacial and Plastic Surgery,  Uppsala University Hospital, Uppsala, Sweden    S. Ebenezer  Department of Oral Surgery and Stomatology, University of Bern,  Bern, Switzerland    © The Association of Oral and Maxillofacial Surgeons of India 2021    It is obvious that a thorough medical history should be  obtained before implant treatment and prior to augmentation  procedures. Patients should be evaluated regarding their gen-  eral health status, medical history, history of any medication,  allergies, the use of tobacco and compliance to oral hygiene  methods. Patients with conditions that affect bone healing  would be poor candidates for augmentation procedures.  Patients with a history of head and neck radiotherapy, uncon-  trolled diabetes, transplant patients undergoing prolonged  immunotherapy, patients undergoing bisphosphonate ther-  apy or medications that could induce osteonecrosis of the  jaws, heavy smokers and patients with neuropsychiatric dis-  orders are high-risk patients to undergo augmentation.   It is also obvious that prior to undertaking augmentation  procedures, adequate radiographic assessment of the region  should be performed. In most situations, Cone Beam  Computed Tomography (CBCT) is the imaging of choice.   The use of tilted or angulated implants, narrow implants,  zygomatic implants, short implants or the use of non-  implant-supported prosthesis can avoid the need for augmen-  tations, and this should be discussed with the patient prior to  undertaking augmentation surgery [3, 4].    The alveolar bone is functionally and macroscopically  unique. It is that functional area of the maxilla and mandible  that is responsible for the anchorage of teeth. Both the man-  dible and the maxilla are irregular bones and are of mesen-  chymal origin. The maxilla consists for the most part of  cancellous bone with a thin cortex layer, whereas the man-  dible has more cortical bone and is denser. As the alveolar  process of the maxilla and mandible are basically functional  components to support the teeth, after tooth loss, the alveolar  bone starts to resorb. However, the pattern of bone resorption  in the two bones is different. The maxillary alveolar bone    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1-15-1346-6_19    resorbs from the labial plate inwards and the mandibular  alveolar bone from the lingual plate outwards. Therefore, in  the cases of long-standing edentulousness, this resorption  pattern results in a narrower maxilla and mandible. The bone  height is also reduced in a vertical direction in areas of tooth  loss, leading to a reduced alveolar bone height in the maxil-  lary posterior area (beneath the sinuses) and a reduced dis-  tance from the crest to the mandibular canal in the posterior  mandible. The sagittal relation is also affected due to jaw  atrophy, leading to an often retrognathic maxilla in relation  to the wider mandible. In short, both the width of the bone  (also called the volume of bone) and the quality of bone  (described by Lekholm & Zarb and Cawood & Howell), [5,  6] must be taken into consideration before implant place-  ment. Additionally, due to ridge resorption, the vertical and  sagittal bone relations between the upper and lower jaw-  bones and the toothless space must be taken into consider-  ation before implant placement and bone augmentation,  when treatment is planned from a prosthodontic point of  view. Figure 19.1 shows the changes in edentulous jaws and  the classification of bone quality and bone quantity as  described by Lekholm and Zarb, 1985.   Also, in patients with tooth loss secondary to other rea-  sons of bone loss such as trauma, pathologies, etc.; bone  should be replaced to reconstruct the lost tissue as well as to  support placement of implants in the best prosthetically  driven position.    tion, bone can be designated as cancellous bone (also called  spongiosa or trabecular bone) and cortical bone (also called    Fig. 19.1 Classification of Upper Jaws  bone for implant placement  by Lekholm and Zarb, 1985.  Adapted from Lekholm and —  Zarb, 1985 [6]  Shape A  Lower Jaws    compact bone). Cortical bone is the dense outer aspect of  bone that is responsible for the mechanical strength. The  inner cancellous part of the bone that predominantly consists  of bone marrow and provides nutrition to the bone [7].   Microscopically cortical bone consists of concentric cir-  cles of osteons (also known as Haversian systems) (Fig. 19.2).  Each osteon consists of a central canal of nerves and blood  vessels that is surrounded by layers of compact bone.  Microscopically, cancellous bone architecture consists of  bone organised into a three-dimensional lattice framework  called trabeculae. The trabecular spaces are filled with blood  vessels and marrow. Bone marrow is a specialised connec-  tive tissue that produces erythrocytes, leucocytes, platelets  and osteoblasts. Depending on age and location, bone mar-  row additionally contains fat cells and other connective tis-  sue elements [8].   Under higher magnification, bone can be further desig-  nated as woven or lamellar bone. Woven bone is immature  bone that forms following injury to mature bone (such as  fractures or tooth extraction) or during the foetal growth  period. After an injury to mature bone that causes a break in  its continuity such as tooth extraction, a haematoma results  and following this woven bone is formed rapidly to fill the  defect in the bone. This bone is mechanically weak and its  collagen fibrils have a random orientation. Woven bone is  then replaced by mature and mechanically strong lamellar  bone that has collagen fibrils arranged parallelly and regu-  larly into distinct layers.   Bones of the human body are in a constant state of  renewal, the process known as bone remodelling. Bone  remodelling is essential to regulate mineral balance in the  bone and circulatory system, as well as to maintain bone  strength. Regular day stress and strain causes microdamage  in bone, which is repaired and replaced by new bone by the    Fig. 19.2 Cross-section of  bone showing a cortical bone  and spongy/cancellous bone.  Please note the osteon  containing a central canal  with blood vessels and nerves  surrounded by concentric  lamellae with osteocytes and  lacunae    process of bone remodelling. Therefore, the process of bone  remodelling helps the bone to adapt to changing mechanical  and biologic needs during the lifetime of the individual. For  the ease of description, bone remodelling can be divided as  consisting of four continuous stages:    During the resorption phase, specialised cells called  osteoblasts are activated, which eat away old bone. In the  reversal phase, bone-forming cells known as osteoblasts  begin to appear on the surface of the resorbed bone. In the  bone-formation phase, the osteoblasts lay down osteoid,  which is the unmineralised organic portion of bone and bone  mineralisation occurs when calcium hydroxyapatite and  other minerals are incorporated into the organic unminer-  alised osteoid, thereby providing mechanical strength. Bone  remodelling occurs all throughout life and consists of a  closely coupled phenomenon of bone apposition and resorp-    tion. Under normal healthy conditions in adults, bone resorp-  tion and apposition during remodelling are balanced in time,  space and amount so that the bone mass of the body remains  more or less constant.    Bone is a connective tissue that consists of bone cells (approx-  imately 10%) in a connective tissue matrix (approximately  90%). Cells of the bone are the osteoblasts, the osteocytes and  osteoclasts. The osteoblasts are large uninucleate cells that  form bone. They work in groups and predominantly lay down  the collagen matrix known as osteoid. Osteoblasts also pro-  duce proteins such as bone morphogenetic proteins that stimu-  late bone healing and mineralisation. About 10% of the  osteoblasts become entrapped inside the calcified bone matrix  and are known as Osteocytes. Osteocytes reside in small bone  cavities known as lacunae and are interconnected with each  other and with osteoblasts and lining cells on the bone surface.  Osteoclasts, on the other hand, are multinucleated cells that  line the surface of the bone where resorption takes place.    These cells release powerful degrading enzymatic proteins  that are responsible for the removal of bone minerals.   The extracellular bone matrix consists of about 35%  organic and 65% inorganic materials. About 90% of the  organic phase is collagen type I fibres, while the remaining    10% consists of various non-collagenous proteins. The bone  matrix also contains growth factors such as the bone mor-  phogenetic proteins important for bone healing. The inor-  ganic phase of the bone matrix consists of low-crystallinity  carbonated hydroxyapatite [9].    19.4 Bone Grafts and Bone Substitutes  Currently, there are a wide variety of biomaterials that can be  used for bony augmentation [10].   Table 19.1 describes the classification of bone grafts [11]  (Adapted from Katsuyama H., Jensen S.S. Treatment Options  for Sinus Floor Elevation).   Most commonly, bone grafts and bone substitutes are  classified according to their source of origin in relation to the  intended recipient. Autogenous or autologous bone grafts are  obtained from the same individual. Allogeneic bone grafts or  allografts are obtained from a genetically distinct individual  of the same species. In contrast, xenogeneic bone grafts or  xenografts are obtained from a different species than the  intended recipient. Alloplastic bone substitutes are syntheti-  cally produced materials.   Autogenous bone graft or autograft refers to bone origi-  nating from the same patient, and it can be harvested from  intra-oral or extra-oral sites. It is preferred to harvest the  bone as close to the surgical defect as possible in order to  avoid donor-site morbidities. However, of course this deci-  sion is dependent on the amount of bone required. For  smaller augmentations and guided bone regeneration, bone  is commonly harvested from the bone tissue neighbouring  the defect site. In this case, donor-site access can be gained  from the same incision that is used to access the recipient  site. In cases where slightly larger amounts are needed, bone  can be harvested from the anterior mandibular ramus or the  mandibular symphysis. These are the most common intra-  oral bone donor sites. Although one may need an additional    Autogenous  bone Origin: Allogenic bone = Xenogenic Alloplastic  the same Origin: another —_ bone Origin: bone Origin:  person human another species synthetic  Block graft Fresh frozen bone Bone from Calcium  another animal phosphates  such as bovine,  porcine  Particulate Freeze-dried bone Materials from Glass  bone allograft corals ceramics  Demineralised Materials Polymers  freeze-dried bone derived from  allograft calcifying algae  Deproteinised Metals    bone allograft  Adapted from Katsuyama H and Jensen S.S: 2011 [11]    incision to harvest bone in intra-oral sites, these can be  obtained in the same surgical area. When even larger amounts  of bone are needed, harvesting from extra-oral sites is  needed. The most commonly used donor sites are the iliac  bone, the calvarium and the tibia. In most of these cases with  the need of an extraoral donor-site harvest, the surgical time  as well as hospital stay is often prolonged. A more detailed  explanation of different donor sites is provided in the section  on onlay bone grafting. In the case of very large bony recon-  structions where the defect size is more than 6 centimetres,  vascularised bone containing free flaps are used, such as the  free fibula flap [12, 13]. These procedures are commonly car-  ried out for benign and malignant tumours, and are not  described in this chapter, but described in detail in the rele-  vant chapter of this textbook.   Allogeneic bone graft or allograft refers to bone originating  from another human, either a living donor or following the  death of an organ donor. Usually, the allogeneic bone is har-  vested from the iliac bone or tibia and can be fresh-frozen,  freeze-dried or processed as demineralised freeze-dried bone.   Xenogeneic bone substitute or xenograft is bone-substitute  material originating from another species. These could be  sea algae, corals, equine (originating from horses), porcine  (originating from pigs) or most commonly, bovine (originat-  ing from cows).   Bone-substitute materials can also be manufactured  purely by synthetic means, produced in the laboratory. These  are called alloplastic graft materials examples of these are  hydroxyapatite, beta-tricalcium phosphate, calcium silico-  phosphate, bioglasses, polymers, titanium particles or a com-  bination of these.   Block bone grafts/Particulate bone grafts: Depending  upon the shape and constitution of the bone graft, they  can be described as block bone grafts or particulate  bone grafts or a combination of these. Bone blocks are  large pieces of autogenous bone. Autogenous bone that  has been harvested by bone scrapers and chisels is in  the form of small chips and is referred to as a particu-  late graft. Particulate grafts can also be made from  block grafts by using special milling machines to break  down the block (Fig. 19.4a, b).    Fig. 19.4 (a) an example of block bone graft (b) an example of a particulate bone graft    19.4.1 Classification of Bone Grafts Based  on the Mechanism of Action    Bone grafts can also be described and classified based on the  mechanism of action and biological activity into osteogenic,  osteoinductive and osteoconductive.    Osteogenic grafts provide a source of new bone forma-  tion by the osteoblasts that are present in the graft mate-  rial. At present, this can only be seen in the cases of  autogenous bone grafts, where the donor bone is from  the same subject and the transplantation procedure has  preserved the viability and vitality of osteoblasts in  them. Developments using stem cell harvesting may  enable development of osteogenic bone grafts without  the use of the subject’s own bone tissue.   Osteoinduction is defined as the mechanism  whereby a bone-substitute material induces bone for-  mation by stimulating undifferentiated mesenchymal  cells to turn into osteoblasts, which in turn produce  new bone. Many proteins such as bone morphogenetic  proteins are being investigated for their osteoinductive  properties.   Osteoconduction is the mechanism whereby bone  formation is enhanced by providing a scaffold for  osteogenic cells that are present in the local environ-  ment of the host. Osteoconductive materials form a  passive support for cells to migrate and colonise the  scaffold and then produce new bone.    In spite of the large number of products available in the  market, the gold standard in bone augmentation is autoge-  nous bone. Depending on the indication for grafting and the  amount of graft needed, autogenous bone can be used in a  particulate form that is used either stand alone, or mixed with  a bone-substitute material, used encased in titanium meshes  or membranes, as a block graft, or as combination of any of  these. Vascularised autogenous bone grafts such as the free  fibula flap, the iliac crest and scapula free flap can be used  not only as bone flaps but also as composite tissue to recon-  struct complete jaws.   Bone augmentation and healing of the graft occurs in the  following stages [14]: The surgical intervention gives rise to  a haematoma and an acute inflammatory reaction, which is  similar to the most cases of tissue trauma. This inflammatory  reaction invokes a migration of inflammatory cells into the  region, along with osteoblasts and osteoblast precursor cells.  In a day’s time, proliferation of blood vessels and the begin-  ning of granulation tissue formation occur. This phase is fol-  lowed by the resorption of the graft by osteoclast precursor  cells, and in the case of autogenous bone, this releases bone  morphogenetic proteins from the bone matrix, marking the  start of the osteoinductive activity. At the same time, osteo-  blasts from the host bone start to migrate into the grafted  region and begin to produce new bone, marking the phenom-  enon of osteoconduction. The graft is over time incorporated  into the regional host bone by undergoing varying degrees of  resorption and remodelling.   Although the procedure is largely similar regardless of the  origin of the bone graft, the properties of osteoinduction and  osteoconduction as well as biocompatibility can vary  depending upon the particular bone-substitute material in    use. Most bone-substitute materials are osteoconductive and  vary in the resorption and bone turn-over rates. As a result,  certain materials are shown to completely resorb within a  period of a few months, whereas certain bone-substitute  materials are present after many years.   Autogenous bone is the only type of graft that contributes  to bone regeneration via all three mechanisms. A limited  number of osteoblasts survive the procedure of grafting and  these cells contribute towards osteogenesis; the graft itself  provides a scaffold for osteoblasts from the host site to  migrate into, facilitating osteoconduction; finally, the growth  factors included within the graft matrix and released during  graft resorption facilitate osteoinduction. Autogenous bone  also has a high rate of resorption.   Allogeneic bone grafts are classified as mineralised and  demineralised. Mineralised allografts—such as fresh frozen  bone allograft and freeze-dried bone allograft—contribute to  bone regeneration primarily through osteoconduction, but  they may also possess some potential for osteoinduction. On  the other hand, demineralised freeze-dried bone allograft is  said to contribute to bone regeneration primarily through  osteoinduction, and only secondarily by osteoconduction.  However, it should be noted that variations in the processing  of allogenic bone grafts from different tissue banks using dif-  ferent methodologies result in a large variation in the compo-  sition as well as osteoconductive potential of demineralised  freeze-dried bone.   The choice of a commercially available bone-substitute  material is most commonly based on the preference of the  recipient patient (some patients would not like bone substi-  tutes from an animal source or a cadaveric source), the avail-  able product information and documentation of clinical  success, product availability, the ease of use and the prefer-  ence of the clinician.    Barrier membranes are an important component for the suc-  cess of the GBR procedure. Ideally, the barrier membranes  must be non-toxic, biocompatible, cell occlusive with a cer-  tain degree of permeability for diffusion of nutrients, permit  bonding and ingrowth of connective tissue during healing,  should be of sufficient rigidity to maintain the space created  and not collapse into the defect, it should be easy to handle  clinically and should be able to be trimmed to tailor the  material as per the size of the defect [15].   Although traditionally many materials such as PTFE had  been developed as membranes, currently most membranes  being used are made up of collagen (type I, type II or a com-    bination of these) [16]. These collagen membranes are  derived from porcine or bovine sources [17]. Collagen mem-  branes resorb as a result of enzymatic action of macrophages  and polymorphonuclear leukocytes. Some manufacturers  cross-link collagen membranes with glutaraldehyde to  reduce the rate of membrane resorption, thereby prolonging  the barrier function. However, crosslinking with glutaralde-  hyde can result in cytotoxic residues in the membrane fol-  lowing its manufacture. Resorbable membranes have a less  likelihood to cause early membrane exposure, and that addi-  tionally due to the property of being resorbable, they do not  need to be removed at a second surgical procedure.   Clinically, the main advantage of resorbable membranes  is their decreased susceptibility to infective complication. If  premature membrane exposure occurs, secondary soft tissue  healing takes place within 4 weeks, and the bone-regenerative  outcome remains favourable. Collagen membranes are also  easier to handle clinically and adapt well to the surgical site  once they are wet with blood or saline. Significantly, the  membranes do not need to be removed via a second surgical  procedure because they biodegrade. The main disadvantage  is that non-cross-linked collagen membranes collapse easily  because they do not have space-maintaining properties.   When a membrane with insufficient stiffness and rigidity  is used in larger defects, there is a high likelihood of mem-  brane collapse. Collapse of the membrane would lead to a  situation where there would be no space for guided bone  regeneration. Hence, clinically this problem is solved by  using a bone graft or a bone-substitute material that fills the  bone defect and provides support to the membrane. Other  methods to support the barrier membranes include the incor-  poration of bendable titanium frameworks into PTFE mate-  rial, tenting screws to support the membrane and titanium  mesh that can be shaped and adapted to the site. However,  these procedures would require an additional surgical proce-  dure to remove the hardware [18].    The success of bone augmentation is dependent on the abil-  ity of the augmented bone to support an implant fixture at the  desired position. However, in biological terms the extent of  graft incorporation, turnover, replacement, the volume sta-  bility and the time taken for healing are dependent on many  factors such as surgical factors, patient-related factors and  material-related factors. It has been shown in multiple sys-  tematic reviews and innumerable clinical studies that there is  no one single superior bone-substitute material [14]. Bone    augmentation, although having well-documented success  rates, depends upon surgical as well as patient-related fac-  tors. Amongst the surgeon-related factors are the training of  the surgeon, their surgical expertise, the adherence to proto-  col and treatment of the graft material as well as the recipient  site, adequate fixation of the graft to prevent movement  between the graft and recipient bone and so on.   Patient-related factors that contribute to healing include  underlying systemic diseases such as immunodeficiency,  diabetes; local factors and habits such as oral hygiene and  oral health, smoking and use of tobacco and defect-related  factors such as the size of the defect and the morphology of  the defect. It should be noted that smaller augmentations in a  three-walled defect are more successful than large only verti-  cal bone augmentation.   Regarding the influence of the grafted material used, it  has been shown that particulated autogenous bone has the  advantage of relatively fast incorporation in comparison with  autogenous bone blocks [19]. However, particulate bone  lacks structural stability and is prone to undergo unpredict-  able and extensive resorption. In contrast, autogenous bone  blocks provide structural stability leading to better dimen-  sional stability. However, block grafting requires a longer  healing period of at least 6 months with about 50% (half the  initial augmented volume) resorption at the end of the heal-  ing period.   Regarding the influence of bone-substitute materials,  there exists a large variation in the physicochemical charac-  teristics of the various bone substitutes available in the mar-  ket, including their composition, particle size and form and  surface properties. These differences can result in varying  outcomes following augmentation.   Differences in the amount of new bone formation can be  due to true differences in the osteoconductive potential of the  biomaterial, but may also partly be explained by differences  in resorption capacity amongst the various bone substitutes,  which in turn determine the space available for new bone tis-  sue formation within the defect site. For example, beta-  tricalcium phosphate is replaced rather quickly, while  sintered bovine bone is resistant to resorption and will be  present in the augmented site for decades.    Currently implantology has developed rapidly. Newer tech-  niques and materials are constantly being introduced. The  choice of procedure depends mainly upon the surgeon. Based  upon the amount of bone augmentation required, the com-  monly carried out procedures are:    Guided bone regeneration is a bone-augmentation technique  that uses the principle of space maintenance within a bony  defect with the use of a barrier membrane. The barrier mem-  brane excludes rapidly proliferating epithelial cells and con-  nective tissue fibroblasts, thus allowing the ingrowth of  slower-growing bone cells and blood vessels into the blood  clot within the defect.   The concept of guided bone regeneration was introduced  and developed first by Nyman and colleagues; Dahlin and  colleagues in the early 1980s [20, 21]. Multiple animal stud-  ies showed that bone defects protected by a barrier mem-  brane, which did not permit ingress of cells, had increased  bone fill as compared to defects that were not protected by a  barrier membrane. Although the technique was first described  for periodontal defects around natural teeth, later studies  showed that GBR was also predictable in forming bone  around implant defects.   Clinically, GBR is performed by raising a mucoperiosteal  flap and exposing the bony defect. This defect is filled with a  bone substitute and then covered with a barrier membrane.  The bone defect with the bone substitute is filled with blood,  which later clots and forms a haematoma. Over a period of  time, the haematoma is ingressed by blood vessels and osteo-  progenitor cells from the surrounding environment, which  over a period of time forms bone tissue by resorbing the  existing substitute and replacing it or growing into the substi-  tute that acts as a scaffold. The barrier membrane prevents  the ingress of fast proliferating fibroblasts and epithelial cells  into the bone defect, thereby creating a space for bone to  form and mature.   However, GBR does not produce similar successful out-  comes in all morphology of defects [22]. The more the bone  walls the defect contains, the better the bone fill following  GBR. Bone walls provide an exposed surface of bone-  recruiting cells. With more bone walls, an increased number  of osteogenic cells are able to migrate along newly prolifer-  ating blood vessels into the haematoma in the defect. When  two or three walls are present, the blood clot is less likely to  be moved and better protected during the healing phase.   Guided bone regeneration can be applied for the correc-  tion of minor requirements of bone augmentation. They are  documented to be successful in the following clinical  situations:    Fig. 19.5 (a, b) Shows a clinical case of GBR for a 2 walled defect    1. Used to augment 2- or 3-walled crestal bone defects when  implants are placed into extraction sites.   4. GBR can be performed as a combination to other larger  augmentation procedures.   5. GBR can be used for contour augmentation to increase  the thickness of the facial bone for aesthetic reasons.    Guided bone regeneration can be successfully used in cases  with crestal bone defects that are seen while placement of  implants into extraction sites. If an implant can be placed  with sufficient primary stability and results in a 2 or 3 walled  defect, or if the defect is well contained in the bony envelope,  GBR can be successfully performed at the time of implant  placement. If these factors are not present, the augmentation  must be performed prior to implant placement as a staged  approach. In these cases, depending on the size and morphol-  ogy of the defect, augmentation can be performed either by  GBR, or by other augmentation methods described later in  the chapter.   Figure 19.5a, b shows a case of GBR augmentation of 2  walled defect.    Often when implants are placed in the correct prosthetic  position, with the correct angulation in order to provide  screw retained restorations, the ideal angulation of place-  ment would result in an apical fenestration, with the apical    part of the implant threads being exposed. In these situations,  the fenestration defects can be covered by using particulate  bone/substitute material, covered with a membrane, as per  the principles of GBR.    During preoperative assessment and after extraction of a  hopeless tooth that is planned to be restored with an implant,  it is essential to inspect the shape of the resulting socket. In  many situations, either due to trauma or chronic infection,  the facial bone wall is missing. In these cases, it is important  to augment the ridge/preserve the ridge at the time of tooth  extraction. GBR can be well employed for this procedure  known as ridge preservation/alveolar ridge preservation. In  cases of acute infection in the sockets, ridge preservation can  be carried out at a later stage after the infection has  subsided.    In the cases of localised prolonged ridge atrophy, GBR can  be combined with other methods of augmentation such as  with block grafts or ridge split techniques. In the cases of  prolonged ridge atrophy affecting a complete segment of the  jaws, the bone defects would often contain a single wall or  two walls with a requirement for larger volumes of grafting.  GBR alone will not provide a sufficient amount of bone aug-  mentation. In these situations, it is advisable to augment  using block grafting, and in addition use particulate bone  graft around the blocks and protect the augmented particu-  late material with a membrane. Implant placement can then  be carried out after a period of around 6 months.    One successful method of placing implants is following  4-8 weeks of healing. In this situation, in contrast to imme-  diate implant placement, soft tissue healing would have  taken place, thereby permitting the clinician with better qual-  ity of soft tissues while placing implants. However, in this  scenario, especially in the aesthetic zone, the resorption of  the facial bone would produce crater-like bone defects. GBR  can be done in these situations, to over correct the lost facial  bone as well as provide bulk to the region of implant place-  ment. This procedure is also called ‘contour augmentation’  [23]. By doing this procedure, the buccal bone wall is inten-  tionally overbulked so as to provide long-term stable aes-  thetic results as shown by multiple studies [24].    Onlay bone grafting is a predictable procedure carried out  for the correction of cases with severe ridge resorption,  either horizontally or vertically [25]. Autogenous bone  grafts are the most documented and commonly used donor  bone, although recently other allogenic and xenogenic  materials are being clinically investigated. For augmenta-  tion of severe ridge defects (less than 2 walls and require  more than 3 mm of augmentation), augmentation utilising  autogenous bone blocks results in increased success rates as  compared to guided bone regeneration alone. However, irre-  spective of the augmentation technique, vertical-ridge aug-  mentation is less predictable as compared to horizontal-ridge  augmentation [26].   Donor sites for autogenous onlay bone augmentation may  be intra-oral or extra-oral. Most common intra-oral donor  sites are the mandibular symphysis and the ramus of the  mandible. Most common extra-oral donor sites for harvest-  ing non-vascularised bone grafts are the iliac crest, the cal-  varium and the tibial bone. Most common vascularised bone  containing free flap donor sites are the free fibula flap, the  DCIA-free flap and scapula-free flap.   Once the bone graft is harvested, they should be trimmed  and shaped to fit into the recipient site defect, stabilisation  with osteosynthesis screws followed by adequate soft tissue  mobilisation and tension-free primary closure of the grafted  site. It is advisable to over-augment the defect in order to  compensate for the eventual resorption. A mixture of particu-  late bone, slow-resorbing xenografts either alone or in com-  bination is used to fill up the area between a corticocancellous  block and the recipient site. The augmented material may be  protected with a barrier membrane prior to being enveloped  by the soft-tissue closure.   The outer cortical plate of the ascending ramus of the man-  dible is a popular choice for the harvest of intra-oral bone.  This is probably because many oral and maxillofacial sur-  geons are well accustomed to the approach to the ramus dur-  ing routine mandibular third molar surgeries or routine  orthognathic surgeries. (Fig. 19.6a, b, c shows harvest of  bone from the mandibular ramus).   The incision starts with a crevicular incision around the  last standing molar teeth and continues along the ridge curv-  ing buccally upwards along the external oblique ridge. After  elevation of the mucoperiosteal flap, and gaining adequate  access to the anterior and lateral border of the ascending  ramus of the mandible and the angle region, bone harvesting  can begin. Usually, a block graft of approximately  30 mm x 15 mm can be harvested. The block thickness  depends on the thickness of the lateral cortical bone plate of  the ascending ramus and can vary from about 3 to 4 mm. The  outline of the graft is usually made with two parallel anterior  and posterior osteotomy cuts of about 3 mm in depth, on the  lateral surface of the ramus of the mandible till the cortical  bone is penetrated completely. Round bur points can also be  made outlining the bone graft prior to making parallel cuts.  Use of piezosurgery is advantageous in the cases of bone  grafting. The two horizontal osteotomies are then joined by  the sagittal bone cut superiorly. This cut corresponds to the  thickness of the cortical bone. Once the sagittal bone cut is  complete, the bone graft can be gently fractured and mobil-  ised by the introduction of an osteotome or a periosteal ele-  vator. Some surgeons prefer to make a cortical cut at the  inferior end of the bone block prior to introducing the perios-  teal elevator to prevent unfavourable fractures of the block  graft. After bone harvest, the surgical area is irrigated well  and a haemostatic agent is applied if necessary and the  wound is closed in layers. Some surgeons prefer to insert a  glove drain that will be removed after 3 days.   The chin is also a popular donor site, predominantly because  of the ease of access to the donor site. However, block grafts  from the chin have shown an increased risk towards compli-  cations, especially neurosensory and vascularity distur-  bances to the mandibular incisors. Bone grafts of 50 mm in  length and about 8 mm of width can be harvested. The corti-  cal portion of the anterior mandible is thicker (around  3-11 mm) and hence the chin would provide a thicker area of  bone and would be a choice for thick bone grafts. It is also  popular to harvest bone grafts from the chin using trephine    Fig. 19.6 Shows harvest of bone from the mandibular ramus. (Picture access to ascending ramus. (b) Outline of the osteotomy. (c) Graft fixed  courtesy PD Dr.med.dent. Simone Janner, Department of Oral Surgery _ at recipient site. (d) Coverage with membrane following additional par-  and Stomatology, University of Bern, Switzerland). (a) Incision for _ ticulate augmentation. (e) Closure    Fig. 19.7 (a, b) Shows harvest of bone from mandibular symphysis. (Picture courtesy PD Dr.med.dent. Simone Janner, Department of Oral  Surgery and Stomatology, University of Bern, Switzerland). (a) Harvest of bone from symphysis. (b) Graft secured at recipient site    burs of varying diameters (7-12 mm), and using upto 4 tre-  phine harvests. (Fig. 19.7a and b shows harvest of bone from  mandibular symphysis).   The access to the chin is by a standard vestibular incision  from one canine to another with approximately 15 mm away  from the mucogingival margin. Once the mucosa is incised,  the underlying mentalis muscle is seen, which is incised  obliquely to reach the symphysis of the mandible. Full thick-  ness flap is elevated and the donor site inspected. For har-  vesting larger grafts, it is advisable to expose both the mental  foraminae. Once the donor site is exposed as per the require-  ment, the boundaries of bone harvesting are carefully noted.  An intact area of 5 mm must be preserved inferior to the root  ends of the anterior teeth and 5 mm above the lower border  of the mandible. Bone graft can be outlined within these bor-  ders, either using piezo surgical device or round burs or fis-  sure burs or most popularly, trephine burs. After the outline  of the bone graft is made, osteotomy of the cortical portion is  done and connected. An osteotome or a periosteal elevator is  then gently introduced to tease out the graft.   After harvesting of the bone graft, haemostasis is achieved  and the wound closed in layers. It is important to close the  periosteal layer and approximate the mentalis muscle prior  to mucosal closure. A compressive chin dressing is provided  to apply pressure to the donor-site region.   Iliac bone provides a large quantity of bone and is the  preferred donor site for large bone augmentation as it is  an excellent source for cortical and cancellous as well as  corticocancellous bone. Both the anterior and posterior  iliac crest can be used as a donor site. Anterior iliac crest  grafts are associated with higher complication rates of    sensory disturbances, gait problems and untoward ilium  fracture. Posterior crest grafts are associated with lesser  complications but increased post-operative pain.  Additionally, posterior crest grafts require the patient to  be repositioned and hence many surgeons prefer the ante-  rior iliac crest. (Fig. 19.8a, b, c shows a case of harvest of  bone from iliac crest).   The harvest of bone from the anterior iliac crest is gen-  erally performed with the patient under general anaesthe-  sia. The patient is positioned supine and the side of the  pelvis to be operated on is raised by placing surgical tow-  els or sandbag towels underneath the hip. The skin over  the crest is made taut by placing a fist above the iliac crest  and only pushing the abdominal wall medially. The skin  incision is made generally about 2 cm larger than the  intended length of the bone harvest, running parallel to  the iliac crest, so that after relaxation of the taut skin, it  lies lateral to the iliac crest thereby avoiding mechanical  irritation of the scar. After skin is incised, blunt dissection  of the subcutaneous tissue is made until the periosteum of  the iliac crest is seen. Bleeding should be controlled dur-  ing dissection. The periosteum of the iliac crest is incised  and the periosteal layer with the attached muscle is ele-  vated and reflected medially. The iliac fossa is dissected  to the desired depth. Care should be taken to avoid injury  to the lateral femoral cutaneous nerve. Bone can be har-  vested using an oscillating saw or a piezosurgical device  as per the preference of the surgeon by splitting the outer  cortex of the iliac crest and transverse bone cuts. The two  transverse cuts are then joined by a cortical osteotomy at  the inner table paralleling the crestal cut. An osteotome is  used to gently fracture the bone graft. This results in a  cortico cancellous bone graft. Additional cancellous bone    Fig. 19.8 (a, b, c ) Shows a case of harvest of bone from iliac crest used to augment anterior maxilla. (a)Shows the exposure of the anterior iliac  crest for bone harvesting. (b) Shows the osteotomy of iliac crest for harvest of bone. (c) Shows the harvested bone fixed at recipient site    can be taken with a large curette if needed. The wound is  meticulously closed in layers and a pressure dressing is  applied.   Calvarium is a good source of cortical bone graft due to its  high density and is opined by some surgeons as being the  most resistant to resorption [27]. The location of the donor  site is at the parietal bone lateral to the sagittal suture. The  bone has distinct outer and inner table at this region sepa-  rated by a diploic layer. A typical situation where calvarial  bone grafts are harvested is in the cases of residual deformi-  ties following trauma, where a bicoronal flap and exposure  of the parietal bone are already planned. (Fig. 19.9a, b, c  shows a case of calvarial bone harvest used for bone aug-  mentation of the anterior mandible).   The harvest is performed under general anaesthesia and  the parietal bone exposed as part of the bicoronal flap. The  outline of the bone graft is first made with round burs and  then joined with straight fissure burs. The outline of the graft    is broadened to permit placement of a chisel that would frac-  ture the outer cortical plate at the diploic space. Haemostasis  is achieved and the wound is closed.    The preparation of the recipient site is done by a crestal inci-  sion with adequate releasing incisions as required. The sur-  face of the bone is cleared of soft tissue and the cortical bone  plate of the recipient site is perforated with a small round bur  to produce bleeding and gain access to the cancellous part of  the recipient bone. The harvested bone is then placed onto  the recipient site and fixed with osteosynthesis screws. Some  surgeons prefer to use lag screws for additional compression.  The spaces between the block graft and recipient bone can be  filled with particulate bone, especially at the borders. A  resorbable membrane may be used to cover the augmentation.  Adequate soft tissue release must be performed prior to    Fig. 19.9 (a, b, c) shows a case of calvarial bone harvest used for bone  augmentation of the anterior mandible. (a) Shows the exposure of the  donor site with the outline of bone to be harvested. (ba) Shows the    closure, so as to provide a tension-free watertight closure.  Onlay grafts are usually left to heal for at least 6 months,  after which implant placement can be carried out as another  surgical procedure.   Another variation of onlay bone grafting is to use the cor-  tical shell technique, where a thin cortical shell of bone is  harvested and cancellous bone marrow placed in between the  cortical shell and the recipient bone wall.   Other methods of bone augmentation include ridge  split for lateral augmentation, alveolar distraction osteo-  genesis for vertical augmentation, interpositional bone  grafting and free flap reconstruction of extremely resorbed  ridges [28, 29]. These procedures will not be described in  detail as they are not the most commonly carried out  procedures.    Sinus floor elevation, also known as sinus augmentation or  sinus lift is a bone-augmentation procedure to gain an  increased bone volume to support in the maxillary sinus fol-  lowing sinus pneumatisation. The bone augmentation is done    cancellous side of the harvested bone. (bb) Shows the cortical side of  the harvested bone. (c) Shows the harvested bone further shaped and  fixed at the recipient site    to provide an adequate quantity of bone that would permit  dental rehabilitation with implants.   Maxillary sinus floor elevation can be performed by either  as a transcrestal technique (also known as indirect sinus floor  elevation) or a lateral window technique (also known as  direct sinus floor elevation).   Irrespective of the individual techniques, the principle is  to elevate the Schneiderian membrane and to create space for  bone to fill up between the elevated Schneiderian membrane  and residual maxillary bone. Although most clinician com-  monly use bone grafts to fill the space between the mem-  brane and the floor, it has also been shown that bone fill  occurs irrespective of using a bone substitute or leaving the  elevated area to be occupied by a blood clot that eventually  forms bone [30-32]. (Fig. 19.10a, b, c, d shows a clinical  case of sinus floor elevation with blood clot and no addi-  tional biomaterial).   The maxillary sinus is a pyramidal-shaped cavity in the  posterior region of each of the maxillary bones. The base of  this pyramid is the lateral nasal wall and the tip of the pyra-  mid is within the zygomatic buttress. The infraorbital floor,  the posterior maxillary wall and the alveolar process form  the walls of the pyramid. The maxillary sinus communicates    Fig. 19.10 (a, b, ¢, d, e) shows a clinical case of sinus floor elevation between the implant and membrane that will eventually fill with blood  with blood clot and no additional biomaterial. (a) Preparation of lateral _ clot). (d) Closure of the lateral window. (e) Long-term follow-up radio-  window and elevation of the sinus membrane. (b) Implant osteotomy graph showing successful implant placement and restoration    to the lateral nasal wall through the semilunar hiatus at the  posterosuperior aspect below the medial nasal concha. At  birth, the maxillary sinus is very small and underdeveloped.  As the permanent teeth begin to erupt, the maxillary sinus  increases in size and continues to grow along with age. The  sinus floor (the alveolar bone) is concave in shape with the  lowest dip corresponding to the maxillary molar region.  However, after the loss of maxillary posterior teeth, the sinus  usually dips into this region. Over a period of time due to the  increasing pneumatisation of the sinus, the sinus may sur-  round the roots of the maxillary posterior teeth. In the case of  the loss of maxillary posterior teeth, the maxillary sinus  expands thinning the floor of the alveolar process that may  result in a thin shell of bone. In many situations, this expan-  sion of the maxillary sinus leaves an inadequate amount of  bone to support successful implant placement. In these situ-  ations, maxillary sinus floor elevation is the procedure of  choice to augment bone. However, it is also important to bear  in mind that alveolar bone resorption may give rise to verti-  cal and horizontal deficiencies in the posterior maxillary  sinus. In prolonged cases, this might give rise to a situation  where along with sinus floor elevation, it would also be nec-  essary to augment bone both horizontally and vertically by  onlay bone augmentation.   The morphology of the maxillary sinus floor can vary.  Maxillary sinus floors are often irregular corresponding to  the elevations and depressions of the teeth roots. The floor of  the sinus also may be divided by septae. Some maxillary  floors are broad and flat whereas others may be irregular and  narrow. The lateral wall of the maxillary sinus can also vary  in thickness, from being paper thin to being about 3 mm in  thickness. The thicker the lateral wall, the more difficult  would be the lateral sinus floor-augmentation procedure.   The blood supply of the maxillary sinus arises from the  branches of the maxillary artery namely: the posterosuperior  alveolar artery and the greater palatine artery as well as the  infraorbital artery. Care must be taken to look out for the  posterosuperior alveolar artery that may be encountered  while preparation of the lateral sinus floor augmentation,  although it is unlikely to cause excessive bleeding.   As required for all surgical procedures, a thorough preop-  erative assessment must be carried out prior to sinus floor  elevation. Acute sinusitis, oro-antral communications,  chronic periodontitis and poor oral hygiene pose a high risk  for sinus floor elevation. Moderate risk factors include smok-  ing, chronic sinusitis and extremely poor bone density,  amongst others.    According to the International Team for Implantology, the  edentulous posterior maxilla can be classified into 4 types [11]:    Group 1: where there is an insufficient sub-antral bone height  to place implants, however with an adequate width of the  alveolar ridge with acceptable vertical and horizontal  interarch relations. These cases can be treated with a sinus  floor elevation procedure alone.   Group 2: where there is an insufficient subantral bone height,  and an inadequate width of the alveolar ridge with accept-  able vertical interarch relation. In these cases, sinus floor  elevation should be performed along with horizontal-  bone augmentation.   Group 3: where there exists an insufficient subantral bone  height, and an adequate width of alveolar ridge with  acceptable horizontal interarch relations but with unfa-  vourable vertical interarch relationship. In these cases,  sinus floor augmentation should be performed along with  vertical-ridge augmentation.   Group 4: There exists insufficient subantral bone height,  and unfavourable interarch relations in addition to  advanced horizontal and vertical crestal resorption.  These cases must be treated with sinus floor  elevation along with horizontal and_vertical-ridge  augmentation.    Misch 1987 [33] classified the edentulous posterior max-  illa based on the amount of subantral bone available into:   SA2: 0-2 mm less than the ideal bone height (10-12 mm).  SA3: 5—10 mm of the subantral bone height.    Transcrestal technique avoids the use of a large surgical  flap and an osteotomy for a lateral window and hence is  much reduced in invasiveness and decreased post-opera-  tive morbidity to the patient. However, the transcrestal  technique can predictively increase bone height to about  4—5 mm and, therefore, cannot be used for severely atro-  phic cases. Additionally, in situations where the sinus  floor is not uniform (or at oblique angles), there is an  increased tendency to perforate the sinus mucosa. In such  cases, it is preferable to perform lateral sinus floor eleva-  tion. It must be remembered that the transcrestal tech-  nique is in essence a blind procedure and it is not possible  to inspect the sinus mucosa for perforations or patholo-  gies using this technique, hence in the cases of intra-oper-  ative perforation, a lateral sinus floor elevation procedure  must be performed. Hence, it is wise to always obtain a  consent for the lateral technique prior to undertaking the  transcrestal procedure.    The prerequisite of simultaneous implant placement is the  possibility to obtain sufficient primary implant stability  [33, 34]. In cases where primary implant stability cannot  be obtained, implants should be placed at a second surgi-  cal procedure 2-6 months following sinus floor elevation.  Decreased residual bone volume and poor bone density  are factors that predispose towards poor primary implant  stability. Traditionally, less than 5 mm was considered as  the minimum amount of sub-antral bone height required  for simultaneous implant placement. This has. However.  been challenged and many recent studies have shown suf-  ficient primary stability in cases with lesser sub-antral  bone height. Implant stability has been achieved in these  cases by using a tapered implant design, implants with  engaging threads, by using the underdimensional drilling    protocol and by _ using’ bone-condensing drills.  Conventionally, it is understood that while undertaking a  transcrestal procedure, implants would be _ placed   Armamentarium for sinus floor elevation consists in  addition to the regular minor surgical kit and the implant  kit, hand and rotary instruments that are specifically  designed for sinus floor elevation. Many companies have  introduced kits specifically for this procedure. Some sur-  geons prefer the use of piezosurgery for access to the lat-    eral window. Additionally, implant companies have also  introduced specific burs and elevation kits that reportedly  make sinus floor elevation easier to perform. It is ulti-  mately the preference of the surgeon in choosing the  armamentarium.    Fig. 19.11 (a, b, c, d) shows a diagrammatic representation of tran-  screstal sinus floor elevation. (a) Implant osteotomy made 2 mm short  of the sinus floor. (b) Osteotome introduced through the implant oste-    After local anaesthesia, a crestal incision is made and  the implant osteotomy is performed according to the  instructions of the respective implant manufacturer. The  osteotomy is made 2 mm short of the sinus floor. A peri-  apical radiograph can be taken to confirm this. After the  depth has been defined, remainder of the implant prepa-  ration is done as per the respective manufacturers proto-  col. Following preparation of the implant bed of  appropriate dimension (it is recommended to use an  implant of at least 4.0 mm diameter till further evidence  suggests otherwise), an osteotome is introduced into the  implant bed and with the help of a mallet, gentle tapping  is performed till the sinus floor is fractured. Care should  be taken that the osteotome does not perforate the sinus  mucosa and enter the sinus cavity. Once the sinus floor  has been fractured, a part of the membrane can be visu-  alised to be intact. A careful Valsalva procedure can also  be performed to test the patency of the sinus floor. An  appropriate graft material is introduced through the  implant preparation onto the sinus mucosa. Incremental  introduction of the graft material is done, which will  push the sinus membrane upwards creating a space  between the sub-antral bone and the sinus mucosa. After  introducing the appropriate amount of graft material, an  implant is inserted to the desired three-dimensional posi-  tion. Following implant installation, the crestal incision  is closed with either a transmucosal or submerged heal-  ing protocol. Implant loading is done as per the instruc-  tions of the manufacturer, generally within 3 month  time. (Fig. 19.11a, b, c, d shows a digrammatic represen-  tation of transcrestal sinus floor elevation).    otomy to fracture the sinus floor. (¢c) Biomaterial introduced to elevate  the sinus membrane. (d) Implant placement completed    A periapical radiograph must be taken at the end of the  procedure to confirm no breach of the sinus floor. A well-  circumscribed dome-shaped elevation around the apex of  the implant confirms no breach of the sinus membrane. In  contrast, if the bone graft is seen around the sinus floor  and poorly localised, it denotes a perforation of the sinus  floor membrane and in this case, a lateral window  approach should be immediately done to clean the sinus  cavity.    The lateral window technique can be done alongside lateral  and vertical augmentation of the ridge, and with or without  simultaneous implant placement. After adequate local anaes-  thesia, a crestal incision is made with releasing incisions  well away from the planned window. A mucoperiosteal flap  is elevated and the lateral wall of the maxillary sinus is  exposed. A bony window is made according to the local bone  anatomy. If vertical septae are present, two bony windows  are made on either side of the bony septae. The bony window  should be large enough to introduce the graft materials, as  well as big enough to permit exploration of the floor, the  anteroposterior aspect of the floor to the medial aspect of the  maxillary sinus. When the lateral window is made, care  should be taken to avoid perforation of the sinus membrane.  The lateral window can either be removed from the underly-  ing sinus mucosa or be attached to the to it and pushed  inwards. The sinus floor is then slowly teased and reflected  away from the floor of the maxillary sinus and elevated using  special instruments that resemble a curette to create space for  the graft material. It is important to elevate the membrane   (Fig. 19.12a, b, c, d shows diagrammatic representation of  the procedure for sinus floor elevation using a lateral  window).   If simultaneous implant placement is planned, implant  osteotomies should be carried out with the elevated mucosa  well protected with an instrument in such a way that the  implant drills do not come in contact with the sinus mucosa.  Bone graft material is now introduced into the space created  by elevation of the membrane. After adequate filling of the  space with augmentation material, implants can be placed if  planned. The lateral window bone wall (if preserved) can be  replaced, or the window can be covered with a barrier mem-  brane. The mucoperiosteal flap is then closed and tension-  free suturing should be placed.   Although, bone graft materials and membranes are com-  monly used it is not mandatory for the success of sinus floor  elevation. Some suggest, elevation of the sinus mucosa and  placement of the implant that tents the membrane up, the  blood clot that is formed into the space eventually forms  bone to surround the implant.    Sinus perforation is the most common complication follow-  ing sinus floor elevation. Other complications include (but  not limited to) poor primary implant stability, implant migra-  tion into the sinus, graft migration into the sinus and intra-  operative and post-operative bleeding, wound dehiscence  and infection.    Fig. 19.12 (a,b,c, d shows diagrammatic representation of the proce-  dure for sinus floor elevation using a lateral window). (a) Mucoperiosteal  flap elevated to access the lateral wall of the maxillary sinus. (b) Lateral    wall bony window made and in-fractured. (c) Implant osteotomy done.  (d) Placement of biomaterial and implant    implants [35], angled or tilted implants [3], zygomatic or  pterygoid implants [36] are treatment alternatives that may  avoid the need for maxillary sinus floor elevation.    ITI Treatment guides Volume 5: Sinus floor elevation  ITI Treatment guide Volume 7    . Chappuis V, Rahman L, Buser R, Janner SFM, Belser UC, Buser    D. Effectiveness of contour augmentation with guided bone regen-  eration: 10-year results. J Dent Res. 2018;97(3):266—74.    sional bone and soft tissue alterations post-extraction in esthetic  sites. Periodontol 2000. 2017;73(1):73-83.    implants in the edentulous maxilla with a fixed provisional restora-  tion without bone augmentation: a report on 5-year outcomes data  obtained from a prospective clinical trial. Int J Oral Maxillofac  Implants. 2016;31(5):1164—70.    . Trbakovic A, Bongenhielm U, Thor A. A clinical and radiological    long-term follow-up study of narrow diameter implants in the aes-  thetic area. 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Thor A, Wannfors K, Sennerby L, Rasmusson L. Reconstruction  of the severely resorbed maxilla with autogenous bone, platelet-  rich plasma, and implants: 1-year results of a controlled prospective  5-year study. Clin Implant Dent Relat Res. 2005;7(4):209-20.  Dasmah A, Thor A, Ekestubbe A, Sennerby L, Rasmusson  L. Marginal bone-level alterations at implants installed in block  versus particulate onlay bone grafts mixed with platelet-rich plasma  in atrophic maxilla. A prospective 5-year follow-up study of 15  patients. Clin Implant Dent Relat Res. 2013;15(1):7-14.   Smolka W. Calvarial grafts for alveolar ridge reconstruction prior  to dental implant placement: an update. Oral Maxillofac Surg.  2014;18(4):381—5.   Chiapasco M, Casentini P, Zaniboni M. Bone augmentation pro-  cedures in implant dentistry. Int J Oral Maxillofac Implants.  2009;24(Suppl):237-59.   Milinkovic I, Cordaro L. Are there specific indications for the  different alveolar bone augmentation procedures for implant  placement? A systematic review. Int J Oral Maxillofac Surg.  2014;43(5):606—25.   Riben C, Thor A. Follow-up of the sinus membrane elevation tech-  nique for maxillary sinus implants without the use of graft material.  Clin Implant Dent Relat Res. 2016;18(5):895—905.   Riben C, Thor A. The maxillary sinus membrane elevation proce-  dure: augmentation of bone around dental implants without grafts-a  review of a surgical technique. Int J Dent. 2012;2012:105483.    32. Duan DH, Fu JH, Qi W, Du Y, Pan J, Wang HL. Graft-free maxil-  lary sinus floor elevation: a systematic review and meta-analysis. J  Periodontol. 2017;88(6):550-64.   34. Stefanski S, Svensson B, Thor A. Implant survival following sinus  membrane elevation without grafting and immediate implant instal-  lation with a one-stage technique: an up-to-40-month evaluation.  Clin Oral Implants Res. 2017;28(1 1):1354-9.    Srinivasan M, Vazquez L, Rieder P, Moraguez O, Bernard JP, Belser  UC. Survival rates of short (6 mm) micro-rough surface implants:  a review of literature and meta-analysis. Clin Oral Implants Res.  2014;25(5):539-45.   Tuminelli FJ, Walter LR, Neugarten J, Bedrossian E. Immediate  loading of zygomatic implants: a systematic review of implant sur-  vival, prosthesis survival and potential complications. Eur J Oral  Implantol. 2017;10(Suppl 1):79-87.    Open Access This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.  org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropri-  ate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.   The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in  a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.   Relationships like symbiosis, commensalism, ectoparasit-  ism, and endoparasitism exist between various species in the  biological world. An infection is a classic example of either  ectoparasitism or endoparasitism. All infections occurring in  the human body are usually of microbial origin and odonto-  genic infections are no exception.   This relationship is based on discordance in the delicate  balance between the host defense mechanism and pathoge-  nicity or the virulence of the infecting microbes depending  upon their potentially harmful biomolecules viz. exotoxin,  endotoxin, enzymes, and others that disrupt the host defense.  Essentially, the environment also seems to play an important  role in the overall pathogenic behavior of the microorganism.  This interrelationship can be expressed by a simple triangle.    In short, when a low host resistance, pathogen-friendly  environment, and a pathogen of high virulence are seen in  states of physical being, we refer to as Infections    A. Shukla - D. Mehrotra   Department of Oral and Maxillofacial Surgery, King George’s  Medical University, Lucknow, India    © The Association of Oral and Maxillofacial Surgeons of India 2021    As a generalization, host defense mechanisms may be stud-  ied as   The oral mucosa forms the first line of defense  against the pathogens with an epithelialization rate of  4-5 days wherein the entire oral mucous membrane is  replaced by newer more equipped cells take its place.  The cells that are infected or otherwise worn out are  replaced. As both the skin and oral mucosa are keratin-  ized structures, water and along with it the microbes  cannot naturally percolate into the deeper tissues. The  oral mucosa is water resistant and relatively dry and  does not form a congenial niche for microbial adher-  ence and growth.   Human dentition has evolved to chew the food we  eat. The surface anatomy of the occlusal surfaces is  such that with a fibrous diet, the food automatically  spills off the occlusal table into the labio-lingual vesti-  bule. The interdental contacts are also evolved and  provide natural spillways for masticated food.   The microscopic structures of our dentition reveal  the hardest substance of the human body (the dental  enamel) to cap its relatively softer structures (dentin  and pulp). Thus, even if microbes are able to hold onto  the enamel layer, the sheer density and mineralization  of this layer are sufficient enough to handle most of the  microbial attacks.    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1-15-1346-6_20   By virtue of evolution, the human race has been  privileged with 3 pairs of major salivary glands and  numerous minor salivary glands. Their secretions, on  the one hand, keep the oral environment moist to avoid  inadvertent trauma and, on the other hand, help trans-  form the chewed food into a bolus to be swallowed.  Salivary secretion continues throughout the awake  state, so even if one is not eating, the salivary secre-  tions flush out the food debris deposited on the hard  and soft surfaces of the mouth, in conjunction with the  movements of the muscular elements of oral region  such as lips, cheek, tongue, etc. Other physiological  properties of the human saliva such as pH (6.5-8.5)  and the presence of immunoglobulins (IgG and IgA)  makes saliva a biological bacteriostatic fluid.   A large number of immunocompetent cells, such as  the mononuclear leukocytes, T cells, and B cells, are  present between the oral mucous membrane and are  responsible for the production of antibodies as well as  offering a direct cellular immune response to the host  and oral environment. The cell concentrations of IgG,  IgA, and IgM may remarkably reach 85, 72, and 75%,  respectively, with respect to plasma concentration, in  the gingival sulcular fluid. However, generally only  IgA levels are high in the oral mucosa, while the con-  centrations of IgG may rise dramatically during infec-  tious states. Also, the true ponderance of mast cells in  the submucosal layer and the presence of IgE explain  the immediate hypersensitivity (type I) reaction. The  role of these immunoglobulins is to neutralize the  microbial toxins and maintain hemostasis in the oral  environment.   If the bacterial attack breaks the enamel barrier, the  toxins reach the dentinal tubules and through them irri-  tate the pulp. This may or may not be symptomatic but  pulpal reaction is evident with the formation of repara-  tive dentin to seal off the breach as part of the defense  mechanism. When this occurs, we know it as arrested  caries and the dentin so formed is the affected dentin.  If due measures are not taken at this stage, an advanced  carious lesion may result.   The OSMIS, lingual tonsil, palatine tonsil, all other  lymphoid structures in the naso-oropharyngeal region  together make a ring-like primary defense mechanism  against microbes in the oro-digestive tract and are con-  stitutionally known as the Waldayer’s ring.   e Systemic Mechanisms: Broadly speaking, the systemic  host immunity may be classified as.  1. Cellular.  2. Humoral.    Both these immune systems may be either innate (natural) or  acquired (adaptive). Majority of pathogens are dealt with by  the innate component of the host systemic immunity.  However, when the innate response is overwhelmed, the  adaptive or active immunity comes into play.    Innate immunity is basically a receptor-pattern recogni-  tion mechanism, where about 100 intracellular and extracel-  lular receptors (e.g., toll-like receptors, NOD-like receptors,  KIG like receptors, etc.) recognize over 1000 different cell  injury-related patterns generated from bacterial, viral, or  fungal inflictions [1]. These receptors generate a response  mediated by cytokines and antiviral interferon and stimulate  the most proactive immune response.   Acquired immunity is of two types, viz. humoral immunity,  mediated by soluble proteins known as antibodies (produced  by B lymphocytes) and cell-mediated immunity effected by T  lymphocytes (T cells). While antibodies provide protection  against extracellular pathogens in blood, mucosa, and tissues,  T lymphocytes work to defend against intracellular microbes  to kill ingested microbes by production of soluble proteins  mediators, the cytokines (produced by helper T cells).    The concept of an infectious agent was established by Robert  Koch. Koch’s postulates became the standard for defining  infectious agents, but they do not apply to uncultivable    organisms (e.g. M. leprae) or members of normal humoral  flora (e.g. E. coli).   1. The same organism must be present in every case of  that disease but not in any healthy individual.   2. The organism must be isolated from the diseased  individual and cultured.   3. The isolate must cause the disease, when inoculated  in a healthy individual.    Odontogenic infections arise within or around the dentition,  initiating from simple dental caries, periodontal diseases, and  pulpitis, and may spread way beyond their loco-regional origin,  invading deeper structures of the face, oral cavity, head and  neck, and even mediastinum or the vertebral column.   These infections are principally bacterial in nature  Tables 20.1 and 20.2. These bacteria are a part of normal  oral flora found in the dental plaque, mucosal surfaces,  and the gingival sulcus. These primarily are aerobic gram  positive cocci, anaerobic gram positive cocci, and gram  negative rods [3].    Types of bacterial infections Percentage  Anaerobic only 50%  Mixed anaerobsic and aerobic 44%  Anaerobic only 6%   2. Facultative gram negative (e) Tannerella forsythia  bacteria (f) Porphyromonas gingivalis    20.4 Pathways of Odontogenic Infection  Odontogenic infections have two major origins (Fig. 20.1).    (a) Periodontal- due to bacterial inoculations into underly-  ing tissues via deep periodontal pockets and   (b) Periapical-, more common, and occur subsequent to  pulpal necrosis, reaching the periapical structures  (Fig. 20.2).    Once the periodontal or periapical tissues get inoculated  with bacteria, the infection may spread equally in all direc-  tions but mostly follows the path of least resistance. It travels  through the cancellous bone to reach the cortical plate. If the  cortical plate is thin, infection easily perforates it to enter the  surrounding soft tissue. Periapical enzymes that help the  bacteria in doing so include collagenase, hyaluronidase, and  streptokinase, which dissolve through the organic matrix of  the bone, while the acids produced by the bacteria eliminate  the mineral content.   At this stage, if an intervention such as an endodontic or  periodontal procedure or dental extraction is done, the fur-  ther spread may be arrested or even abolished with judicious  antibiotics. Antimicrobials alone may not cure the condition  as the focus of infection from necrotic pulp or periapical tis-  sues still remains and may cause recurrence of the infection,  if the therapy is stopped [5].   When left untreated, the infection continues to spread  depending principally on the thickness of bone and the  type of muscle attachment. For example, if maxillary  anterior tooth gets involved in the periapical region and  the inclination of the root is such that the apex is closer to  the labial cortical plate, the soft tissue reaction would  present as swelling on the labial side (Fig. 20.3a) and if  the apex is closer to the palatal cortical plate, swelling  would be palatal. (Fig. 20.3b). Similarly, in case of cari-  ous involvement of maxillary first molar: if the apices of  the buccal roots lie above the attachment of the buccina-  tor, swelling is likely to occur facially (Fig. 20.4a) and if  apices are below, a vestibular swelling is more likely to  occur (Figs. 20.4b and 20.5).   Apart from these factors, the angulation of root apex is  also important. For example, in periapical abscess with  respect to maxillary lateral incisor, swelling is likely to occur  on the hard palate rather than labial vestibule as its root apex  is slightly palato-distally curved. (Fig. 20.6).   Muscle attachment is another influencing factor.  Supposing a mandibular second molar gets apically infected  and the apices lie above the external oblique ridge, infection  following the path of least resistance and assisted with grav-  ity, may manifest as swelling in a more anterior region of the  jaw, buccally than the relative position of the first mandibular  molar. Similarly, in the mandibular posterior region, the lin-  gual cortex is closer to the root apices and relatively thinner    Fig. 20.2 (a, b) shows a lower left second molar with a periapical radiolucency. On extraction, the periapical granuloma can be seen attached to  the root. If this tooth was not extracted, the infection would have progressed in any of the pathways as shown in Fig. 20.1    Fig. 20.3 (a, b) Infection following the path of least resistance in case of maxillary incisors based on angulation of root    Fig. 20.4 (a, b) Effect of buccinator muscle attachment on the site of    appearance of swelling in case of maxillary molars. In (a) the infection  has localised to the vestibule while in (b) the infection has spread to the    Fig. 20.5 Shows the clinical picture of a vestibular abscess arising  from an infected upper right first molar    as compared to the buccal cortical plate. If this gets perfo-  rated above the mylohyoid line, a sublingual swelling occurs  and if below it, a submandibular swelling occurs.   The commonest manifestation of odontogenic infections  is either a palatal or a vestibular abscess. When untreated, it  may lead to an intraoral or extraoral drainage, in due course  establishing a sinus tract. The treatment involves removing  the cause (endodontically or via exodontia) and manage-  ment of the sinus tract. In certain cases, the sinus tract  resolves by itself, following the treatment of the offending  cause (Fig. 20.7).    buccal space, as the root apex is situated above the attachment of the  buccinator muscle    An odontogenic infection follows the path of least resistance.  A periapical infection may perforate the nearest or the weak-  est cortex and travel along the soft tissue, initially as celluli-  tis and eventually resulting in abscess formation. This  abscess may drain spontaneously, extraorally or intraorally  and may involve one or more anatomically potential spaces.  When this happens, it is known as a space infection.    Fig. 20.7 (a, b) Shows the periapical lesion in lower left first molar in a 14-year-old patient causing extraoral sinus at the left lower border man-    3. With any offending mandibular tooth.  Medullary space of mandibular body.   Masticator. ¢ Osteomyelitis of the mandible.  Submasseteric.  Pterygomandibular. MODERATE—Airway may be compromised    Fig. 20.8 Pathways of spread of periapical infection. (1) Vestibular  space. (2) Palatal abscess. (3) Maxillary sinus/odontogenic sinusitis. (4)  Buccal space. (5) Submandibular space. (6) Sublingual space    a proper history should be recorded in chronological  order stating the patients’ chief complaints in his/her own  words.   Once the chief complaint is noted, history of present  illness is determined with an estimation of how long back  the patient was absolutely symptom free. Usually, infec-  tions have a short history of onset as compared to tumors  in their acute state [6].   Next thing to be noted is any change in the patients’  state of physical well-being since the symptoms first  appeared, i.e. if they have been the same, improved, or  worsened with time. Since the response to an infection is  essentially an inflammatory one, classic sign of inflam-  mation are always looked for (tumor, rubor, dolor, color,  and loss of function). Principal presenting feature is pain,  so the nature of pain, site, and diurnal variation should be  noted. A sharp, piercing, and lancinating type of pain is  generated by A6d nerve fibers that usually awake the  patient at night (in accordance with the hydrodynamic  theory of pulpal pain by Brannstrom [7]); however, a dull,  aching, and gnawing kind of pain arises due to stimula-  tion of slowly firing “c” type nerve fibers.   Swelling, redness, and rise of temperature should be  inquired for and inspected even during history taking if  these are apparent. Loss of function may manifest in the  form of dyspnea, dysphagia, difficulty in chewing, or tris-  mus [8]. A feeling of general malaise usually indicates a  physical or physiological response against moderate to  severe infection [9].   At this point, an enquiry into any previous treatments  by another dentist, specialist, and/or self-treatment should  be made and recorded. After carefully listening to the  chief complaints and history of present illness, a compre-  hensive medical history should be recorded. The most  efficient means of doing so is either by personal struc-  tured interview or by means of a questionnaire along with  a discussion with the patient for any positive findings.    History taking is followed by a physical examination  that begins with the recording of patients’ vitals as tem-  perature, pulse rate, respiratory rate, and blood pressure.  Patients with infections usually have elevated body tem-  perature, and increased pulse and respiratory rates [10]. If  the pain is significant, patient’s blood pressure may be ele-  vated. However, hypotension is seen in septicemic states.  Since odontogenic infections are inflammatory states, a  partial or complete upper airway compromise may occur  owing to an extension of the current infection to the deep  facial spaces of the neck [11]. The patients may present  with fatigue, fever, and malaise or so-called toxic appear-  ance (Table 20.3) [12].   Palpation of swellings should be done to know the ten-  derness and consistency of the swelling. Consistency of a  swelling may vary from normal, firm, fleshy (dough like)  to indurated (consistency of a taught muscle/wooden like/  brawny hard), or fluctuant (feel of a fluid-filled balloon).  Fluctuation almost always indicates presence of pus in  the center.   Intraoral examination gives a fair amount of idea as to  the cause of the infection, i.e. the offending tooth. A care-  ful look may reveal a grossly carious tooth/teeth, peri-  odontal diseases, and/or a fractured tooth.   Investigative phase begins with a radiograph; intraoral  periapical (IOPA) or orthopantomogram (OPG) depend-  ing on the symptomatology and clinical examination. CT  scan may be required in severe cases to assess the path-  way of the spread of infection [13].   If any surgical intervention is required, a routine blood  assessment is always helpful in deciding the type of pro-  cedure to be followed.   A decision has to be made as to the stage of the infec-  tion, i.e. inoculation, cellulitis, or abscess stage. Usual  attributes are as follows.    is the guide to detect any interfering systemic conditions  that may compromise the host defense mechanism and  may worsen patient’s condition rapidly. Conditions of  compromised host defense mechanism are as under:    (a) Diabetes Mellitus (type I and II): When uncontrolled,  it results in an overall decrease in the immunity  owing to decreased phagocytosis, chemotaxis, and  generalized decrease in leukocyte function.  However, in patients with moderate to severe infec-  tion, an increased random blood sugar cannot be a  diagnostic criteria for underlying diabetes. Since  these are high-stress states, the body gluconeogenic  mechanisms are upregulated to meet the increased  BMR. So, a more comprehensive analysis like  HBA,.C is performed to know the long-term glyce-  mic status.   (b) Leukocytic upsurge is expected in infection. The  baseline leukocyte/neutrophil count serves as a  marker to track the response of the patient to medical  and surgical intervention in a case of severe odonto-  genic infection.   (c) Immuno-deficient states: HIV infection principally  affects the T lymphocytes, meaning that the humoral  immune system is still intact. Odontogenic infections  are generally bacterial and usually well defended by  the patients’ immune system, but in immunocompro-  mised states, the basic host defense mechanism no  longer functions. When the disease advances to  involve even the B-cells, then, even simple infections  may become serious life-threatening issues in such  patients. It is hence important to know that such  immunocompromised HIV-positive individuals need  more intensive therapy than a normally infected  individual.   (d) Another example of systemic immuno-deficient  states may be prolonged corticosteroid therapy. Here  the inflammatory cascade itself gets modulated, and  affects the immune system as a whole, resulting in  decreased production of the cell adhesive molecules,  deficient leukocyte chemotaxis, and decreased cyto-  kines production (IL-1, TN a, IL-6, etc.). No apop-  totic activity results in generalized lymphocytopenia  along with IL-2. mediated  cyto-proliferative  responses. When used long enough or in high doses,  delayed-type hypersensitivity (type IV) response is  inhibited along with decreased antibody formation.  Such patients soon develop oral thrush and other  superimposed bacterial or viral infections of the oral  cavity, worsening of an existing odontogenic infec-  tion being no exception.   (e) End Stage Renal Diseases (ESRD): End stage renal  diseases affect almost all aspects of the innate and  acquired immunity, and many such patients will be  on maintenance hemodialysis. ESRD patients having  odontogenic infections also may have to be managed   (f) Drug-induced immuno-incompetence: While blood  counts less than 1000 cells/ml are typically seen in  patients on anti-cancer chemotherapy, patients who  undergo organ transplants have to be on immune-  suppressive therapy (IST). Drugs like corticosteroids  and cyclosporins have decreased B and T lymphocyte  function and consequently deficient immunoglobulin  production. As such, patients are likely to have exag-  gerated manifestation for even mild odontogenic  infections.   (g) Alcoholism and/or Hepatic insufficiency: Alcoholics  are usually malnourished and have pending hepatic  damage that leads to poor qualitative and quantitative  immunoglobulin supply.   Above discussion reinforces that while assessing a  patient, a through medical history as well as a history  of habits provides vital clues for the action to be  adopted for his/her management.   3. Role of Specialist: Role for patient care should shift from  a general dentist to a maxillofacial surgeon. Antibiotics  should be started if indicated as in Table 20.4. When the  situation demands, either a hospital admission or immedi-  ate surgical care under regional or general anesthesia is  required. The following criteria may be adopted for mak-  ing this vital discussion in patient’s interest:   (h) Moderate to severe trismus (with mouth-opening  between 10 and 20 mm).   (k) Signs of ascending or descending facial infections  (cavernous sinus thrombosis/deep neck infections/  mediastinitis).    4. Surgical Intervention: Surgical drainage and removal of  the course of infection is the mainstay of surgical man-  agement of odontogenic infection [14]. This may be as  simple as endodontic therapy to wide incision in the  submandibular/neck region that may require mediastinal  exploration. The removal of the cause is the primary goal  and drainage of the accumulated pus and necrotic debris  is the secondary goal.   Incision and drainage principally includes insertion of a  drain in the abscess cavity to prevent premature closure of  the mucosal/skin incision. Purpose of this procedure is to  achieve adequate drainage, if it is not possible by end-  odontic means (especially in mandibular teeth) (refer  Chap. 21 for details on incision and drainage).   Pus culture and Sensitivity Tests: This must be done before  the incision and drainage procedure if possible. The site is  prepared with antiseptics and a thick needle is used to  aspirate pus, may be in multiple directions, under nega-  tive pressure of syringe, and taking due care to prevent  relevant anatomic structures. In case of complex space  infections involving the digastric/carotid triangle, ultra-  sound-guided aspiration must be done. This culture when  obtained from sites of cellulitis (Ludwig’s Angina) usu-  ally contains serosanguinous fluid but harbors sufficient  bacteria for culture. This aspirate is inoculated into both  anaerobic and aerobic cultures (sterile tubes having sterile  swabs and bacterial transport medium) with viable shelf  life [15].    Once the culture and sensitivity reports are available, spe-  cific antimicrobial therapy may be installed but meanwhile  empirical antibiotics should be started immediately [16]. The  choice of antibiotic should be carefully thought off to pre-  vent unnecessary disturbance of the essential microflora of  the gut and development of cross resistance (Also refer  Chap. 10 of this book).   Cases of moderate to severe infection generally need  postoperative antibiotics, where the host defense cannot be  solely relied upon to fight the residual infection. Since the  antibiotic sensitivity of usual causative organisms of odonto-  genic infections is fairly well known and consistent, an  empirical therapy may include clindamycin, metronidazole,  and penicillin. Metronidazole being narrow spectrum covers  only obligate anaerobic population and the rest may be cov-  ered by other drugs dealing with facultative microbes.  Odontogenic infections are complex entities, both, on the  basis of the plethora of flora associated and mechanism of  their spread to the adjacent as well as distant anatomic   2. Use of antimicrobial with least toxicity and side  effects- prevents vital organ damage.   3. Use of bactericidal rather than bacteriostatic drug-  prevents residual infection.   5. Use only in prescribed dose and duration- restricts  side effects and maintains efficacy.   6. Use the appropriate route of administration- restricts  side effects and maintains efficacy.    sites. Fortunately, culture and sensitivity behaviors of the  causative microbes are fairly consistent and well under-  stood. As such timely management should alleviate most of  the dangerous outcomes but still these infections remain  one of the leading cause of maxillofacial morbidity and at  times mortality.    Odontogenic infection can be severe enough and become life  threatening, hence should be dealt with very carefully. Proper  evaluation of the signs and symptoms guide the clinician to  make the diagnosis. Radiographic assessment may suggest  the involvement of one or more teeth. Surgical intervention  includes drainage of abscess, and pus be sent for culture and  sensitivity to help choose the right antibiotic regime.    . Newman M, Takei H, Klokkevold P, Carranza F. Carranza’ clinical    Sensation in preparations, caries, and the dentinal crack syndrome.  J Endod. 1986;12(10):453-7.    . Mathew GC, Ranganathan LR, Gandhi S, Jacob ME, Singh I,    Solanki M, et al. Odontogenic maxillofacial space infections at a  tertiary care center in North India: a five-year retrospective study.  Int J Inf Dis. 2012;16:e296-302.    . Hupp JR, Ellis E Il, Tucker MR. Contemporary oral and maxil-   Al-Malik M, Al-Sarheed M. Pattern of management of oro-  facial infection in children: a retrospective. Saudi J Biol Sc.  2017;24:1375-9.   Kuo J, Lin Y, Lin YT. Odontogenic cellulitis in children requiring  hospitalization. J Dent Sc. 2013;8:129-32.   Alotaibi N, Cloutier L, Khaldoun E, Bois E, Chirat M, Salvan  D. Criteria for admission of odontogenic infections at high risk of  deep neck space infection. Eur Ann Otorhinolaryngol Head Neck  Dis. 2015;132:261-4.   Yonetsu K, Izumi M, Nakamura T. Deep facial infections of odon-  togenic origin: CT assessment of pathways of space involvement.  Am J Neuroradiol. 1998;19:123-8.   Sanchez R, Mirada E, Arias J, Pafio JR, Burguefio M. Severe odon-  togenic infections: epidemiological, microbiological and therapeu-  tic factors. Med Oral Patol Oral Cir Bucal. 2011;16(5):e670-6.  Kumar V, Abbas A, Aster J. Robin’s pathological basis of disease.  10th ed. Philadelphia, PA: Elsevier; 2017.   Kuriyama T, Karasawa T, Nakagawa K, Nakamura S, Yamamoto  E, et al. Antibiotic susceptibility of major pathogens of orofacial  odontogenic infections to 11 6 lactam antibiotics. Oral Microbiol  Immunol. 2002;17:285-9.   Topazian RG, Goldberg MH, Hupp JR. Oral and maxillofacial  infections. 4th ed. Philadelphia: WB Saunders Company; 2002.    Open Access This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.  org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropri-  ate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.   The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in  a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.   There is considerable amount of change in the behavior of  infections for the past one decade. The severity of infection  is far greater than before which may be due to increased co-  morbid conditions, demanding swift action and aggressive  treatment.   Fascial spaces do not exist in a normal healthy individual.  These are latent spaces created by distention of tissues sec-  ondary to infection from the dental pulp, periodontal tissues  and bone, where the infection perforates the cortical plate  and discharge into the surrounding spaces.   The infections range from simple superficial periapical  abscess to deep infections in the neck region; some resolving  with little consequences and some lead to life-threatening  conditions.   Shapiro states that “The fascial planes are potential areas  between layers of fascia. These areas are normally filled with  loose connective tissue, which readily breakdown when  invaded by infection”. The infection started in any area is  automatically limited by tough fascial layers. If the infection  becomes massive, it breaks through a nearby fascial barrier  into the next fascial space [1].    The fascial spaces in the Head and Neck are the potential  spaces between the various fascia normally filled with loose  connective tissue and bounded by the anatomical barriers  usually of bone, muscle, or fascial layers [2].   Facial planes offer anatomic highways for infection to  spread superficially to deep planes. Antibiotic availability in  fascial spaces is limited due to poor vascularity.    © The Association of Oral and Maxillofacial Surgeons of India 2021    The spread of the infections could be either through tissues,  blood, or lymphatics leading to fatal consequences like Airway  obstruction, Meningitis, and Septicemia; however, various fac-  tors influence the spread of infection.   e Thickness of bone adjacent to the offending tooth.  e Position of muscle attachment in relation to root tip.    In the Oral and Maxillofacial region, fascial spaces are  almost always of relevance due to the spread of odontogenic  infections. As such, the spaces can be classified according to  their relation to the upper and lower teeth, and whether infec-  tion may directly spread into the space called primary space,  or must spread via a primary space to the secondary space [3].   21.4.1 Primary Spaces and Secondary Spaces  Failure to adequately treat a primary space infection or a  compromised host results in secondary space involvement  (Table 21.1).    the neck that limits the spread of infection, the spaces can be  classified according to their relation to the hyoid bone:    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1 -15-1346-6_21    Submandibular space  Submental space  Sublingual space  Pterygomandibular space  Submasseteric space and  Temporal spaces   Lateral pharyngeal space  Retropharyngeal space and pretracheal space  Danger space  Mediastinum  Intracranial infection    e Suprahyoid (above the hyoid).  ¢ Infrahyoid (below the hyoid).  ¢ Fascial spaces traversing the length of the neck.   The severity score for a given patient is the sum of the sever-   ity scores for all of the spaces involved by cellulitis or abscess,   based on clinical and radiological examination (Table 21.2).  The fascial spaces are divided into:    The infections arising from the maxillary anterior teeth  spread to Canine space, while the infection from molars  spread to Buccal space, Infratemporal space, or cause palatal  abscess. Likewise, the infection from the mandibular anterior  teeth spread to Submental space or cause gingival abscess.  Infection from mandibular molars spread to the Sublingual  space or the Submandibular space. While the infection from    mandibular third molars spread to Submasseteric space,  Pterygomandibular space and Lateral Pharyngeal space.   However, it is not a “rule of thumb” for the involvement  of a particular space with a specific tooth infection.    Pyogenic infections are primarily managed by surgical  intervention comprising decompression or drainage. It is bet-  ter to proceed with decompression at the earliest, without  waiting for the localization of the infection (abcess forma-  tion), thereby preventing the spread of infection in tissue  planes and mounting of pressure under the skin (Table 21.3).   6. To allow better perfusion of blood thereby improv-  ing the delivery of antibiotics and defensive ele-  ments to the required site.    This is a method of abscess drainage which ensures that no  blood vessel or nerve in the vicinity of the incision is  damaged.    . Stab incision with the help of 11 number blade is    associated with tooth. (b) Stab a  incision given with blade. (c)  sinus forceps is entered into  the cavity and opened. (d)  Drain entered into the cavity.  (e) Drain secured with suture    abscess cavity and secured to the edge of the inci-  sion and the drain is removed once there are no  active exudates.    Fig. 21.1b Hilton’s method b  of incision and drainage  (extra oral site). (a) Incision  given at the dependent site of  the abscess. (b) Sinus forceps  entered into the abscess  cavity. (c) Sinus forceps  opened in the cavity and  removed. (d) Drain entered  into the cavity and secured  with suture    Removal of the source of the infection is mandatory apart  from drainage.    Supportive management is mandatory in the form of antibi-  otics, anti-inflammatory, and electrolytes. The reader is also  advised to refer the chapter on general principles of manage-  ment of facial infections (Chap. 20).    Antibiotics are advised depending upon the patient’s sys-  temic condition; initially, after pus collection, empirical anti-  biotic is given; later, after the culture and sensitivity is  performed, -specific antibiotics are advised.   Route of administration depends upon the general condi-  tion and severity of the infection. Para-enteral route is pre-  ferred when the infection is acute and severe or when the  patient is nutritionally or medically compromised.   With evidence of slough, gas, crepitus, and foul smell,  anaerobic infection may be suspected and appropriate antibi-  otics have to be given.    Flynn TR [5] in their systemic review concluded that anti-  biotics should be chosen which are safe and cost effective,  because no one antibiotic is clearly superior to all others. In  otherwise healthy patient, a 34-day regimen of antibiotic    therapy should be adequate. The primary importance should  be given to the surgical treatment consisting of incision and  drainage, extraction, or endodontic therapy of the involved  tooth. According to their review, the choice of empiric antibi-  otics for odontogenic infections is listed in Table 21.4.   Martins JR et al. [6] suggests that after incision and  drainage/removal of the cause is mandatory. Antibiotics  should be administered for the shortest duration possible  duration and should act as an adjuvant for the primary sur-  gical treatment in countering any regional or systemic  co-morbidities.    Apart from antibiotics and anti-inflammatory drugs,  administration of fluids and electrolytes is mandatory, as  there is a loss of fluids due to infection and fever. In non-  ambulatory patients, intravenous fluids are administered  depending on their systemic status.   Daily calorie requirement also increases by up to 13% for  each degree rise in temperature, which needs to be addressed  for a speedy recovery.    It involves those modalities which aid the patient’s  own body defenses. It consists of the following:   2. Hydration of patient through IV route, maintain  adequate nutritional status-high protein intake.    A simple and superficial abscess can be drained comfortably  under local anesthesia, while deep-seated, multi-loculated  abcesses may not be amenable for treatment under local  anesthesia and may be managed under procedural sedation  provided the patient has adequate mouth-opening and patent  airway.   Fiber-optic intubation or tracheostomy may be considered  in; patients with limited mouth opening (trismus) or in patients    eral/retropharyngeal spaces) where the chances of aspiration  is high in the event of oro/naso-tracheal intubations.   situated in the anterior surface of the maxilla at the infraor-   . Swelling in the anterior cheek region.  . Obliteration of Nasolabial folds.   . Edema of lower eyelid and upper lip.  . Obliteration of labial vestibule.   Drainage of the space infection either intraorally or per-  cutaneously is done; intraoral incision and drainage are  preferred as these will not produce a facial scar. Drainage  is made by making an in-depth incision of the maxillary  vestibule near canine fossa. Sinus forceps is inserted  superiorly, laterally, and medially for complete breakage  of locules and drainage. Care is taken while using sinus  forceps, so as to not damage the infraorbital nerve and  its branches.   Aggressive antibiotic therapy is mandatory to prevent the  spread as it lies in the danger area of the face and also to  prevent Cavernous sinus thrombosis from septic thrombi  entering into angular vein.   The involved tooth is either removed or subjected to root  canal treatment with multiple dressings. Patient is advised  good hydration and rest.    The buccal space occupies the portion of the subcutaneous  space present between the fascial skin, buccinator muscle,  and masseter muscle [8].   From mandibular premolar and molar teeth root apices  below the buccinator attachment.   e Anterior: Posterior border of zygomaticus major above  and depressor anguli oris below.    21.10.2.3 Clinical Features  1. Pain and tenderness.  2. Diffuse swelling on the side of the cheek.    3. Obliteration of buccal vestibule.  4. Swelling of upper/lower lip (Fig. 21.3).   Drainage of the space infection either intraorally or percuta-  neously is done; intraoral incision and drainage are preferred  as these may not produce a facial scar. Drainage is made by  making an in-depth incision of the maxillary vestibule near  the involved tooth. Sinus forceps is inserted superiorly, later-  ally, and medially for complete breakage of locules and  drainage. Care is taken while using sinus forceps, so as to not  to damage duct and artery (Fig. 21.4a, b, c).   For mandibular buccal space infection, intraoral drainage  may not achieve the desired result, hence extraoral drainage  at the lower border of mandible is made taking care of the  facial artery and marginal mandibular nerve.   The involved tooth is either removed or subjected to root  canal treatment as required. Literature advocates early  extraction of the involved tooth/teeth. According to  Igoumenakis D et al. [9], extraction of the involved tooth  shortens the hospital stay and provides faster recovery on a  biological level.    Infections in this region are relatively rare to occur when  involved swelling occurs at the temporal region above zygo-  matic arch and behind the lateral orbital rim [10]. They are  two in number—Superficial temporal space and Deep tem-  poral space (Fig. 21.5).    21.10.3.1 Superficial Temporal Space  This space lies between the temporal fascia and temporalis  muscle.    Fig. 21.4 (a, b, c) Clinical pictures showing the procedure of incision and drainage for buccal space infection (also see Fig. 21.1B)    Fig. 21.6 Clinical image of the classical dumb bell swelling (blue  arrows). The isthmus of the swelling at the zygomatic arch is shown by  the green arrow   Surgical drainage is carried out through an incision made  above the zygomatic arch; sinus forceps is inserted through  the skin incision and passed through the superficial fascia  and the temporal fascia.    This space lies between the temporalis muscle and the skull.  Slightly below the level of zygomatic arch; both the superfi-  cial and deep temporal spaces communicate with each other.    ¢ Medial—Medial pterygoid plate and lower part of infra-  temporal fossa.  e Lateral—Medial surface of the temporalis muscle.   2. Swelling at the infratemporal region and lateral aspect of  the eye.   If the trismus is not severe, intraoral incision is given in the  buccal sulcus at the second and third molar region. With the  sinus forceps, the space is entered medial to coronoid pro-  cess superiorly and the pus is drained. Corrugated rubber  tube is placed and secured with a suture.   In case of severe trismus, extraoral incision is made above  the zygomatic arch at the junction of frontal and temporal  process of zygoma, sinus forceps is inserted and directed  inferiorly and medially to enter the space and drain the pus.  The disadvantage of this approach is that it cannot produce  dependent drainage.    The infection from any of the six anterior teeth in the man-  dible may perforate the labial bone inferior to the mentalis  muscle attachment and the pus may present at the anterior  and lower border of the mandible and below the mylohyoid  muscle lingually [11].   e Infected symphyseal or parasymphyseal fractures.  e Suppuration of submental lymphnodes.   ¢ Lateral: Skin, superficial fascia, platysma, superficial  layer of deep cervical fascia.   e Superior: Medial aspect of mandible and the attachment  of mylohyoid muscle.    Fig. 21.7 Clinical picture showing spread of infection to the submen-  tal space and buccal space   1. Pain and tenderness in the chin region.  2. Firm swelling at the chin.   Transcutaneous approach in the chin region is the most effec-  tive drainage; incision is made below the symphysis menti to  produce dependent drainage. Sinus forceps is inserted  upward and backward to break the locules and the pus is  drained. A corrugated rubber drain is inserted and secured  with a suture. Intraoral approach is cumbersome as we need  to pierce mentalis muscle to reach the submental space and  also drainage against gravity is not possible.    The space is V-shaped lying lateral to the muscles of the  tongue and in the lingual aspect of the body of the mandible.  Anteriorly communicates with submental space and posteri-  orly communicates with the submandibular space at the edge  of the mylohyoid muscle [12].   e Periapical infection from mandibular teeth is situated  above mylohyoid muscle.    Fig. 21.8 Shows the spread of infection to the sublingual space (grey  shaded area)   2. Due to edema, there is elevation and protrusion of the  tongue.   e An intraoral incision is made close to lingual cortical  plate, near premolar region taking care of lingual nerve  and the Wharton’s duct. Sinus forceps or a thin mosquito  forceps is inserted and the pus is drained.   e If an extraoral approach is planned, then incision is placed  at the submandibular region, taking care of the facial artery  and marginal mandibular nerve; a sinus forceps is inserted  piercing the mylohyoid muscle to drain the pus and a cor-  rugated rubber drain is inserted and secured with a suture,  as this approach provides gravity-dependent drainage.    e The submandibular space is present at the inferior border  of the mandible between the anterior and posterior bellies  of digastric muscles [13].   e Infection from the periapical region of molar teeth below  mylohyoid muscle.   e Laterally: Skin, superficial fascia, platysma, and superfi-  cial layer of deep cervical fascia.   e Superiorly: Medial aspect of mandible and the attachment  of mylohyoid muscle.   2. Swelling is situated at the submandibular region, inferior  to the lower of the mandible.   It is managed through an extraoral approach; incision is  placed at the submandibular region in the most dependent  area to facilitate gravitational drainage, taking care of the  facial artery and marginal mandibular nerve; a sinus for-  ceps is inserted superiorly, medially, and laterally piercing  through the superficial fascia. A drain is inserted and  secured with a suture to facilitate dependent drainage  (Fig. 21.10).    Masticator space is formed by splitting of the investing fas-  cia into superficial and deep layers. The superficial layer lies  along the lateral surface of the masseter and lower half of the  temporalis. Deep layer passes along the medial surface of the  pterygoid muscles before attaching to the base of the skull  superiorly.    Masseter consists of three layers which are firmly attached  anteriorly and loose posteriorly. The space is present lateral  to ascending ramus of the mandible.   e Posterior: Parotid fascia and deep portion of parotid gland.  e Superiorly: Level of zygomatic arch.   2. Moderate size swelling at the angle region.  3. Firm consistency swelling.    21.12.1.4 Management  The drainage of the infection is done through two approaches.   In intraoral approach, incision is placed at the retromolar  area along the anterior border of the ramus of mandible. The  sinus forceps is inserted through the incision laterally between  the mandibular ramus and the masseter muscle to explore the  Submasseteric space. The disadvantage of intraoral technique  is that incision and drainage is not gravity dependent.   In extraoral approach, the incision is placed on the skin at  the angle and inferior border of the mandible; sinus forceps  is inserted directing superiorly piercing the subcutaneous tis-  sue and masseter muscle. Abscess drained corrugated rubber    tube is placed and secured with a suture. Precautions are  taken not to damage the marginal mandibular nerve  (Figs. 21.11 and 21.12).    One of the most frequently encountered space in dental  office is pterygomandibular space [14].    Fig. 21.12 Clinical picture showing submasseteric space infection left  side, pus was drained extraorally   e Superior: Lateral pterygoid muscle and infratemporal sur-  face of greater wing of sphenoid bone.   No obvious swelling extraorally.  Swelling near anterior tonsillar pillar.  Deviation of Uvula.   Generally, incision and drainage are done through intraoral  approach; however, in case of severe trismus, extraoral  approach may be indicated. Drainage is done either under  general anesthesia or by giving mandibular nerve block.    Fig. 21.13 Clinical picture of left pterygomandibular space infection  forming a decayed impacted lower left third molar. Note the limited  mouth opening   A vertical incision of 1.5 cm is made at the anterior and  medial aspect of the mandible, sinus forceps is inserted into  the abscess cavity, and pus is evacuated. Corrugated rubber  drain is inserted and sutured to the margins of the incision to  prevent dislodgement.   In case of severe trismus, this approach is advised, an inci-  sion of 1.5 cm is made on the skin, toward the inner aspect of  the angle region. Sinus forceps is inserted toward the medial  aspect of the mandible directing superiorly close to the bone.  Pus is evacuated and rubber drain is inserted and sutured to  the margins of the incision.   Figure 21.14 shows various approaches which can be  used for fascial space infections and Fig. 21.15 shows sub-  mandibular approach to the medial and lateral masticator  spaces.    Fig. 21.14 Shows the extraoral incisions for the space infections, (a)  temporal space, (b) submental space, (c) submandibular space, (d) lat-  eral pharyngeal space, (e) retropharyngeal space    Fig. 21.15 Diagrammatic representation of the approach to the ptery-  goid space (medial) or massetric space (lateral) via submandibular  incision    The spaces around the pharynx form a ‘Ring’ and a pathway  for spread of infections from the orofacial region to the neck  and mediastinum. The Parapharyngeal space includes Lateral  Pharyngeal space and Retropharyngeal space.    It is a potential space lying lateral to the pharynx, extending  from base of the skull to the hyoid bone. The space is conical  in shape, base being toward the base of the skull and apex  toward the hyoid bone.    Retropharyngeal space.  e Lateral: Medial pterygoid muscle, Deep lobe of the  parotid gland.   1. No or minimal external swelling on the lateral aspect of  the neck.   . Pharyngeal bulging is seen (Swelling over pillars of fau-  ces and superior constrictor).   A combination of intra-oral and extra-oral approaches are  advised for the managment of infections of the lateral pha-  ryngeal space. They are preferably done under general anes-  thesia with care taken to secure the airway.   Intraoral approach—A 1.5 cm incision is made on the  Pterygomandibular raphe, sinus forceps is passed through  the raphe on the medial surface of the mandible, medial  aspect of the medial pterygoid muscle, and lateral aspect of  the superior constrictor muscle.   Extraoral approach—An incision of 2.5 cm is made in  the submandibular region, blunt dissection is then carried  through the fascia just anterior to the sternocleidomastoid  muscle, and digital palpation can enter and dissect the lateral  pharyngeal space bluntly (Fig. 21.16). The landmarks to be  palpated are the angle of the mandible anterolaterally, the  carotid sheath posterolaterally, the transverse processes of  the cervical vertebrae posteromedially, and the endotracheal  tube, if present, anteromedially. Caution must be taken not to  perforate the posterior oropharyngeal wall by aggressive fin-  ger dissection toward the oropharynx [15].   Combined approach—Intraoral incision is made on the  mucosa at the medial aspect of the ramus of the mandible,  curved hemostasis is inserted lateral to superior constrictor  muscle and medial to medial pterygoid muscle and the blunt  dissection is carried out posterio-inferiorly below the angle  of the mandible. The tip of the instrument is palpated at the  anterior border of the sternocleidomastoid muscle extra-  orally and cutaneous incision is made over the tip. A drain is  inserted and sutured to the wound margin to allow drainage.   Maintaining the endo-tracheal tube or tracheostomy may  be considered depending on the severity of infection and the  success of drainage.    It is also called as prevertebral space, which is a potential  space present in the midline between the pharyngobasilar    6. Dyspnea.  7. Mediastinitis is the most feared complication of this  space.   Most important is to secure airway, may be an elective tra-  cheostomy or fiber optic intubation is considered for airway  maintenance.   Intraoral approach is generally done for the suprahyoid part  of the retropharyngeal infection, procedure is similar to the  one done for lateral pharyngeal space infection. Intraoral inci-  sion is made on the mucosa at the medial aspect of the ramus  of the mandible, curved hemostat is inserted lateral to superior  constrictor muscle and medial to medial pterygoid muscle,  and the blunt dissection is carried out further inferiorly.   Extraoral approach is better for the infection at the infra-  hyoid region, incision is made transcutaneously anterior to  the sternocleidomastoid muscle at the level of the angle of  the mandible to the level of the hyoid bone. Both sternoclei-  domastoid muscle and Carotid sheath are identified, and  retracted. Blunt dissection is carried out into lateral and ret-  ropharyngeal spaces, later being verified by the palpation of  anterior process of the cervical spine posteriorly and the  endotracheal tube anteriorly [16]. Drain is placed and secured  to the edges of the cutaneous incision.    It is a localized infection near the tonsils, usually occurring  as a secondary infection from the local sites.   8. Change of voice and speech difficulty in case of bilateral  involvement.   Intraoral approach, superficial incision made at the most  prominent area of the swelling near anterior pillar and the  soft palate, sinus forceps is inserted deep into the tissues to  break all the locules and drain the pus [17].    Possible life-threatening complications may be developed if  the space infections of the jaws are not addressed adequately;  for ease of understanding, the complications are classified as  follows (Table 21.5).    It was first described by Wilhelm Friedreich Von Ludwig in  1836, and the term Ludwig’s Angina was coined by Camerer  in 1937. The word Angina is derived from Latin language  meaning suffocation or choking.   Ludwig’s Angina is defined as an acute, firm, non-  suppurating, necrotizing cellulitis involving _ bilateral  Submandibular, Sublingual, and Submental spaces. The con-  dition has been described by medical practitioners, by three  unique features, starting with the alphabet ‘F’—Feared,  Fluctuant rarely, Fatal often.   Many terminologies were used for this condition like  Marbus Strangularis, Angina Maligna, and Garotillo.    21.14.1.1 Source  Predominantly (90%) odontogenic in origin, from the lower  jaw.   Infection from 2nd and 3rd molar teeth may be Acute den-  toalveolar abscess, Periodontal Abscess.    — Pericoronal Abscess. Infected cyst at the body and the  angle of the mandible.   — Traumatic injuries especially to the mandible, either  ignored or not managed well leading to sepsis.   The infection of the sublingual space rapidly spreads along  to its base which is present at the hyoid bone. A characteris-  tic feature is edema of the epiglottis and the vocal cords, due  to the spread of infection in a postero-inferior direction from    the sub-lingual space to the laryngeal inlet. This may pro-  duce acute respiratory obstruction and death [18].    21.14.1.4 Management  It should be treated as life-threatening situation and inter-  vened aggressively   The treatment of Ludwig’s Angina is primarily surgical.  The first priority in the management is always the life-saving  measure. If the patient shows any signs of dyspnea,  Tracheostomy should be performed promptly   e Removal of the cause and surgical drainage and  decompression of fascial spaces.    Endotracheal intubation is nearly impossible due to tris-  mus, tongue elevation, and laryngeal edema. A skilled anes-  thetist with fiber optic laryngoscope may try Nasoendotracheal  intubation, while the patient is conscious and awake, while  the tracheostomy kit is kept on standby, in case of emergency  (please refer Chap. 7 to read about anesthesia procedures in  patients with space infections).   Once the airway is secure, the next step is surgical decom-  pression of spaces and tissue planes; this is achieved by giving  multiple cutaneous incisions in the submandibular and sub-  mental regions. Decompression of sublingual space is very  important, which is achieved by piercing the mylohyoid mus-  cle. This can also be achieved by placing an incision in the floor  of the mouth, parallel to the lingual vestibule. There may not be  much pus to drain as the condition is usually non-supperative  (Fig. 21.18a, b, c). Corrugated rubber drain may be left in situ  to keep the incisions patient and to drain the exudates [19]    Fig. 21.18 (a, b, ec) Clinical pictures showing the drainage of Ludwig’s angina    1. Reduces tension within the tissue planes and pre-  vents further spread of infection.   2. As the pressure in the tissue drops, circulation  improves and facilitates the reduction of the edema.    After decompression, simultaneous removal of the cause  is important, as this is the source of the condition.   Intravenous fluids are administered to maintain proper  fluid and electrolyte balance and to fulfill the nutritional  requirement of the patient. Definitive antibiotics are given  intravenously based on the culture and sensitivity reports.  Other symptomatic medicines like anti-inflammatory and  analgesics may be prescribed. Local wound care is taken  care of by irrigation and dressings. Drains to be changed  every 48 hrs and maintained until the condition resolves.    Necrotizing fasciitis is an uncommon soft tissue infection,  occurs due to polymicrobes and spreads rapidly in the subcu-  taneous tissue and above superficial fascia, and as the disease  progresses, muscle and skin involve giving rise to myonecro-  sis. The other name for this condition is Hospital Gangrene  given by Brooks in 1966 and Hemolytic streptococcal gan-  grene. Necrotizing fasciitis may affect any part of the body;  however, it most commonly affects the extremities, abdomi-  nal wall, and the perineum following trauma or surgery.   The condition shows no clear boundaries or palpable lim-  its, mainly occurs with immunocompromised patients and  those suffering from systemic illnesses (Fig. 21.19).   The causative organisms in this condition are multiple like  Aerobic Group A—hemolytic Streptococcus and  Staphylococcus and later identified microbes are Bacteroids,  Proteus, coliforms, and peptostreptococcus. In most cases,  the pathogens gain entry through disruption of the skin  caused by trauma or surgery. Continuous bacterial over-  growth and synergy cause a decrease in oxygen tension and  develop local ischemia and proliferation of anaerobic bacte-  ria. The fulminating nature of the necrotic process is the  result of the symbiotic relationship between the bacteria.    Systemic Local  High fever Involved area is swollen and erythematous  Weakness Change of overlying skin color to dusky with  purple mottling  Dehydration Visible slough on the surface with underlying  necrotic fascia  Toxic Paraesthesia of the affected area  appearance  Tachycardia Foul smell  Sepsis  Hemolysis  21.14.2.2 Clinical Features (Table 21.7)  21.14.2.3 Investigations    — Complete blood picture (Leukocytosis, Band cells, and  Toxic granules in Leukocytes).   — CT Scans are useful in detecting the deep-seated collec-  tions and the necrosis.   Early recognition and aggressive surgical intervention is  mandatory; taking the medical parameters into consideration  and airway maintenance, general anesthesia is preferred in  most cases.   Initially, intravenous broad spectrum antibiotics are  administered to control the spread of the infection; these  antibiotics may be changed once the culture report is  obtained.    Surgical treatment is obligatory with incision and drain-  age, in addition to vigorous debridement of the necrotic  fascia, subcutaneous tissue, muscle, and skin. Excision of  tissue to the point of fresh bleeding is advised. Multiple and  regular change of dressings are needed till the condition is  resolved.    Cavernous sinuses are the venous sinuses situated on either  side of the sella tursica. The cavernous sinus on either side  communicates freely with each other by anterior and poste-  rior intracavernous sinuses they also communicate with sag-  ittal sinus, transverse, sinus and sigmoid sinus. The cavernous  sinus communicates extra cranially with veins of the head  and neck.    1. The ophthalmic vein and angular veins into the anterior  facial vein.    External route—Infection from face and lips carried by  facial and angular veins and nasofrontal veins to the superior  ophthalmic vein passes through the superior orbital fissure  and enters the cavernous sinus.   Internal route—Infection from the posterior maxillary  region to the pterygoid plexus to the inferior ophthalmic vein  through the inferior orbital fissure and then through the supe-  rior orbital fissure to the cavernous sinus.    21.14.3.1 Source  The area of the face between the inner canthus of the eyes  and the corners of the mouth is called “Danger Triangle’ of  the face and any kind of severe sepsis in this area can spread  in aretrograde manner and can extend to the cavernous sinus  through the angular vein and ophthalmic vein.   ¢ Diplopia due to involvement of 3rd, 4th, and 6th cranial  nerves.    ¢ Increased intracranial pressure due to venous congestion  and cerebral edema.   ¢ Erosion of the internal carotid artery leading to fatal intra-  cranial hemorrhage.    21.14.3.3 Eagleton Criteria  Diagnostic criteria were suggested by Eagleton, prior to  modern investigative methods.   3. Early signs of venous obstruction in the retina, conjunc-  tiva, or eyelid.   The patient should be given broad spectrum intra venous  antibiotics preferably those which cross the blood brain bar-  rier. Aminoglycosides and Clindamycin are started in high  therapeutic doses. [V Mannitol is given to decrease the intra  cranial pressure. Anticoagulant Heparin 20,000 units in  1500 ml of 5% Dextrose is advised to reduce thrombosis.   It is one of the neurological complications resulting from the  infection of oro-facial region. It may develop from meta-  static spread or may be due to nearby thrombophlebitis.    21.14.4.1 Clinical Features  High fever with chills  Irritability and mental confusion  Head ache   Diagnosis is based on cerebrospinal fluid analysis. In CSF  polymorpho-nuclear leukocytes, elevated protein levels and  decreased glucose levels are noticed.    21.14.4.3 Treatment  — Initially with Chloramphenicol 4 g/day-IV associated  with Penicillin G 24 million units per day IV    Odontogenic infections are typically polymicrobial. The  pathogenesis of odontogenic infections depend on a syner-  gistic relationship between aerobic and anaerobic bacteria.   The last decade showed a notable change in the behavior  of odontogenic infections. The severity of these infections is  far greater than in the past, demanding swift recognition of  the disease followed by prompt and more aggressive treat-  ment. Failing to identify and treat these infections promptly  may result in disastrous outcomes.   Definitive treatment includes airway management, ade-  quate resuscitation and optimization of pre-existing medical  conditions prior to removal of the source of infection, and  drainage of pus.   Oral and high-dose intravenous antibiotics should be  administered as required depending on the severity of  infection and based on the decision whether the patient is  treated on an outpatient or inpatient basis, with the initial  choice of antibiotics modified in the light of subsequent  bacteriological reports. The treatment of all odontogenic  infections must include removal of the focus of infection  and drainage of pus.    1. Shapiro DS, Schwartz DR. Exposure of laboratory workers to  Francisella tularensis despite a bioterrorism procedure. J Clin  Microbiol. 2002;40(6):2278-81.   2. Standring S, editor. Gray’s anatomy: the anatomical basis of clini-  cal practice. Philadelphia: Elsevier Churchill Livingstone; 2005.   3. Guidera AK, Dawes PJD, Fong A, Stringer MD. Head and neck  fascia and compartments: no space for spaces. Head Neck.  2014;36(7):1058-68.    4. Mirochnik R, Araidy S, Yaffe V. Imad Abu El-Naaj severity score  as a prognostic factor for Management of Infections of odontogenic  origin, a study of 100 cases. Open J Stomatol. 2017;7:25-34.   5. Flynn TR. What are the antibiotics of choice for odontogenic  infections, and how long should the treatment course last? Oral  Maxillofac Surg Clin N Am. 2011;23:519-36.   6. Martins JR, et al. The use of antibiotics in odontogenic infections:  what is the best choice? A systematic review. J Oral Maxillofac  Surg. 2017;75:2606.e1—2606.e11.   7. Grodinsky M, Holyoke E. The fascial and fascial spaces of the head  and neck and adjacent regions. Am J Anat. 1938;63:367—407.   8. Ansari MK, et al. Management of Odontogenic Buccal Space  Infection in patient with severe hemophilia A-case report. Int Arch  Oral Maxillofac Surg. 2008;2:1-4.   9. Igoumenakis D, et al. Effect of causative tooth extraction on clini-  cal and biological parameters of odontogenic infection: a prospec-  tive clinical trial. J Oral Maxillofac Surg. 2015;73:1254-8.   10. Fiscaletti D, Sorli A. A-temporal physical space and introduction to  the theory of everything. Sci Ing. 2007;8:65—80.   11. Carter LM, Layton S. Cervicofacial infection of dental origin pre-  senting to maxillofacial surgery units in the United Kingdom: a  national audit. Br Dent J. 2009;206:73-8.   12. Kao S, Jo C, Oral and Maxillofacial Infections. Clinical review of  oral and maxillofacial surgery. Mosby. 2014:95-118.   13. Rizzo PB, Da Mosto MC. Submandibular space infection: a poten-  tially lethal infection. Int J Infect Dis. 2009;13:327-33.   14. Khoury JN, Mihailidis $. Applied anatomy of the pterygomandibu-  lar space: improving the success of inferior alveolar nerve blocks.  Aust Dent J. 2011;56:112-21.   16. Albert T, Balderston R, Northrup B. Surgical approaches to the  spine. Philadelphia: Saunders; 1997.   17. Scott GM, Fung K, Roth KE. Novel high-fidelity peritonsillar  abscess simulator. Otolaryngol Head Neck Surg. 2016;154:634-7.   19. Ramadhan A, et al. One incision approach to multiple facial spaces:  technical note incision approach to multiple facial space. Int J Oral  Care Res. 2017;5:9-14.    Flynn TR. Oral and maxillofacial infections: 15 unanswered questions.  Oral Maxillofac Surg Clin North Am. 2011 Nov;23(4):1x—x.    Open Access _ This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.  org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropri-  ate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.   The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in  a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.   Bones belong to the connective tissue. Their main function is  the internal support and source of inorganic ions. Bones have  an organic matrix that is secondarily calcified with calcium  salts, mainly hydroxyapatite. The organic matrix consists of  a huge extent of type I collagen. Only 5% are other proteo-  glycans and non-collagenous proteins [1].   There are two major bone parts: The outer compact and  the interior cancellous part. In the compact bone, the colla-  gen fibrils form concentric lamellae around a central canal  that is called the Haversian canal. These canals harbor ves-  sels which are interconnected by further vessels lying in the  Volkmann’s canals. The fibrils in neighboring lamellae have  a perpendicular orientation resulting in higher stability of the  bone. In between the calcified lamellae are therefore concen-  tric orientated osteocytes. Their main function seems to be  the mineralization of the bone [1]. The compact bone is  responsible for approximately 80% of the entire bone weight  [2]. The main function of the compact bone is mechanical  stability whereas the cancellous bone mainly has a metabolic  function [1]. The cancellous bone consists of small lamellae  and has a surface 10 times bigger than the compact bone [2].  On the outside of the compact bone is the periosteum, on the  inside the endosteum.   There are three kinds of bone cells: The osteoblasts, the  osteocytes, and the osteoclasts.   Oral and Maxillofacial Surgery — Plastic Surgery, Mediplus Clinic  Mainz, Mainz, Germany    © The Association of Oral and Maxillofacial Surgeons of India 2021    Osteoblasts derive from a multipotential stem cell that  differentiates via an osteoprogenitor cell into osteoblasts.  Osteoblasts form new bone by the production of the inor-  ganic matrix that mineralizes eventually. After a cycle of  bone resorption and consecutive bone formation, most  osteoblasts become lining cells covering the surface of the  bone [1].    During the course of bone formation, approximately 10% of  the osteoblasts build themselves into the bony structure and  become osteocytes [2]. It is assumed that the number of  osteocytes is 10 times higher than the number of osteoblasts  in the adult human body. The osteocytes are stellate cells that  have lots of slim processes that are connected to surrounding  cells. Osteocytes with their three-dimensional network seem  to play the key role in bone remodeling [1].    From all bone cells osteoclasts represent the smallest frac-  tion. Osteoclasts are multinucleated giant cells that resorb  bone. They derive from the monocyte macrophage line.  Their only function is to resorb mineralized tissue as it is  necessary for bone growth, remodeling, and tooth eruption.  Most bone diseases are associated with an increased function  of the osteoclasts. Therefore, osteoclasts are often the phar-  maceutical target in the therapy of bone diseases such as  malignancies or metabolic diseases as osteoporosis.  Osteoclasts are regulated by the RANK RANKL OPG sys-  tem [1, 3].    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1-15-1346-6_22    The receptor activator of nuclear factor kB ligand (RANKL)  is an osteoclast differentiating factor mainly expressed by  osteoblasts. Secretion of RANKL leads to the differentiation  of osteoclasts out of precursor cells, and the activation of  osteoclasts to resorb bone by binding on RANK that is  expressed on both the precursor cells and the mature osteo-  clasts. Osteoprotegerin (OPG) is the osteoclastogenesis  inhibitor factor and functions as a decoy receptor for RANKL  so that the osteoclasts cannot be activated. The RANK  RANKL OPG system seems to be the most important part in  the communication between the bone cells.   This system is not exclusively organizing the communica-  tion between osteoblasts and osteoclasts. This system has  been proven to be responsible for the formation of the mam-  mary gland and lymph nodes. RANK and RANKL are also  expressed in the kidney, spleen, thymus, and brain, where it  might influence the thermoregulation [3].    The clinical picture of the different kinds of osteomyelitis is  very inhomogeneous so that there are many definitions and  classifications. In textbooks, the osteoradionecrosis and  medication-associated osteonecrosis of the jaws are often  subentities of the osteomyelitis. In this book, these entities  are described in their own subheadings (Sects. 22.3 and 22.4  of the chapter).    The actual term “osteomyelitis” refers to an inflammation  (“itis”) of the bone marrow (“osteomyel’) only but means an  inflammation of the entire bone including the periosteum,  the cortical, and cancellous bone as well as the bone  marrow.    There are many different classifications that are either based  on the etiology, pathogenesis, pathologic or anatomic differ-  ences, the clinical course of the disease, or radiologic pat-  terns. This makes a comparison between different studies  very complicated or impossible.   The Ziirich classification [4] differs between three differ-  ent kinds of osteomyelitis: The acute osteomyelitis, the sec-  ondary chronic osteomyelitis, and the primary chronic  osteomyelitis (Table 22.1). The secondary chronic osteomy-  elitis results from the acute osteomyelitis and therefore is    Table 22.1 The table describes the Ziirich classification of osteomy-  elitis on the left-hand side. In the right column are the different kinds of  osteomyelitis that are included in the respective group of the Ziirich  classification [4]    Different types of osteomyelitis  Neonatal osteomyelitis  Trauma-associated osteomyelitis  Odontogenic osteomyelitis  Foreign body-induced osteomyelitis  Osteomyelitis based on a bone disease  Osteomyelitis based on a systemic  condition    the same disease at a different time stage. Once the osteo-  myelitis persists for more than 4 weeks, it is defined as  chronic [4].    Due to the different classifications and terms used for the  entire group of osteomyelitis, it is hard to give general data  regarding its epidemiology. Approximately 17% of all osteo-  myelitis cases belong to the group of the acute osteomyelitis,  70% to the secondary chronic osteomyelitis, and 10% to the  primary chronic osteomyelitis [4]. The average age at the  time of diagnosis is a little bit over 40 years for the acute and  the secondary chronic osteomyelitis [4]. Because of the  inhomogeneity of the secondary chronic osteomyelitis, a  general age group cannot be given.    In the etiology of the acute osteomyelitis and the secondary  chronic osteomyelitis, usually an odontogenic infection can  be identified such as a dead tooth, a periodontal disease, or  conditions after dentoalveolar surgery. A hematogenic spread  from a different primary location into the region of the jaws  is extremely rare [4].    The etiology of the primary chronic osteomyelitis is an  infection of unknown origin [4].    The acute osteomyelitis and secondary chronic osteomyelitis  are caused by a local infection due to bacteria from the oral  cavity. The likelihood of the development of the infection  depends on the virulence and number of bacteria and the  quality of the local immune response and the blood flow [4].   Therefore, general diseases affecting the immune system  are risk factors in the development of osteomyelitis, e.g., dia-  betes, autoimmune diseases, or anemia.   A typical course of the acute and secondary chronic  osteomyelitis is the contamination of the bone with bacteria.  The bacteria proliferate and colonize the bone marrow and  reach via the Haversian and Volkmann canals the perios-  teum. The edema under and in the periosteum disturbs the  blood flow resulting in ischemic bone parts and potentially  sequestrum building.    The acute osteomyelitis and the secondary chronic osteomy-  elitis are characterized by an inflammatory exudate, primary  in the medullary spaces with fibrin, leucocytes, and macro-  phages that replace the fatty tissue and hematopoietic mar-  row (Fig. 22.1). In addition, necrotic debris and bacteria can    Fig. 22.1 In this case of acute osteomyelitis, the medullary hemato-  poietic cells and the fatty tissue are completely replaced by cell debris,  fibrin, and an inflammatory infiltrate mainly composed of neutrophil  granulocytes (black arrow). Besides the vital bone with filled lacunes of  osteocytes (yellow arrow), necrotic bone can be seen with loss of osteo-  cytes (blue arrow)    be found [4, 5]. The most common bacteria being detected is  Staphylococcus aureus (85%) [4]. Due to the blood flow dis-  turbances (see pathogenesis), parts of the bone die so that  empty osteocytic lacunae can be observed. Sequestrae may  be present. New bone formation under the periosteum is not  uncommon.   In cases of secondary chronic osteomyelitis, sequestrum  formation is more common than in the acute osteomyelitis.  The more chronic the course is, the more likely is the devel-  opment of bone marrow fibrosis and sclerosis of the bone.  Bacteria might be present. Actinomyces drusen are  typical.   In the primary chronic osteomyelitis, plasma cells are  predominant in the inflammatory infiltrate. The proportion  of neutrophils, lymphocytes, and macrophages is rather  small. The bone marrow is altered due to fibrosis. New  bone formation is a common sign. Osteoclastic activity  leads to repeated bone remodeling without a distinct histo-  logical bone formation pattern. Microabscesses might be  observed [4].    In cases of acute osteomyelitis, patients present with high  fever and are listless. Local swelling can be observed with  pain on palpation. The affected area is reddish, a trismus  might be present, and quite often the teeth have higher mobil-  ity with pus coming out of the periodontium. If the inferior  alveolar nerve is affected, patients report paresthesia of the  lips (Vincent symptom [4]). There are cases in which the  symptoms are not very distinctive.   Symptoms of the secondary chronic osteomyelitis are the  painful swellings that are usually not as prominent as in the  acute osteomyelitis. A common finding is a periosteal reac-  tion causing a solid swelling. Further symptoms are seques-  ter formation and fistulas.   The primary chronic osteomyelitis is characterized by a  nonsuppurative inflammation and sometimes only barely  noticeable symptoms. In active periods, the patients notice  pain, swelling, and mouth-opening limitations. Due to the  bone formation, permanent swelling will develop eventually    A typical complication of the acute osteomyelitis is a shift  into the chronic osteomyelitis that is very hard to treat  sufficiently.   Further complications are the development of the Vincent  syndrome, fistula, abscess and sequester formation, and  potentially fractures [4].    The diagnosis is based on the clinical course. This is com-  pleted by radiology: panoramic radiograph, cone beam CT,  CT, or MRI. Changes in the bone can only be seen after a 30  to 40% reduction of the mineralized part of the bone.  Therefore, the changes in the acute osteomyelitis are mar-  ginal at the beginning. In complex cases of osteomyelitis, a  bone scintigraphy might be used to detect further active spots  in the skeleton, e.g., in the diagnosis of chronic recurrent  multifocal osteomyelitis or the SAPHO syndrome (SAPHO:  Synovitis, acne, pustulosis, hyperostosis, osteitis) [6].  Radiological signs of acute osteomyelitis are: Bone  resorption with increased radiolucency, loss of spongious  structure of the bone, potentially sequester formation.  Radiological signs of the secondary chronic osteomyelitis  are: Bone resorption with increased radiolucency, sequester  formation, periosteal reaction, and pathological fractures.  Radiological signs of the primary chronic osteomyelitis  are: Increased radiopacity with loss of trabecular bone, bone  resorption, and periosteal reaction (Fig. 22.2) [4].    In the differential diagnosis, one should rule out malignan-  cies in unclear cases so that biopsies should be performed.    The therapy of the acute and secondary chronic osteomyeli-  tis mainly consists of the therapy of the infection and of the    Fig. 22.2 Panoramic  radiograph of a patient with  primary chronic osteomyelitis  after several surgeries have  been performed. Several  infusions of pamidronate  prevented the occurrence of  further active periods. In the  left mandible, typical  sclerosis can be seen with a  prominent nerve canal    improvement of the local blood flow. This is achieved via  antibiotics and removing of the infected parts of the bone. A  decortication supports this and helps to get well-vascularized  tissue onto the bone.   Acute osteomyelitis is immediately treated with  antibiotics. If an antibiogram suggests different antibiotics,  an adaptation should be performed after the initial anti-  microbiological therapy. Mouth rinses, hygiene, and cold  application can be applied. In general, the highly mobile  teeth should not be extracted since they will gain stability  again after the acute stadium of the osteomyelitis is over.   The therapy of the secondary chronic osteomyelitis aims  at sufficient pain management, limitation of the spread of the  affected areas, fracture prevention, and the prevention of the  onset of further active periods. Secondary diseases such as  diabetes need to be treated as well.   The therapy of the primary chronic osteomyelitis consists  of a surgical intervention to remove the necrotic bone parts  and a potential disfigurement can be corrected. But recur-  rences of the symptoms are very common. Therefore, other  treatment options should be used as well including antibiot-  ics, nonsteroidal anti-inflammatory drugs (NSAIDS), ste-  roids, and bisphosphonates (mainly pamidronate).    The therapeutic success is higher in patients with acute and  secondary chronic osteomyelitis than in patients with pri-  mary chronic osteomyelitis. Approximately 75% of the acute  and secondary chronic osteomyelitis are symptom-free after  intervention whereas only about 25% are symptom-free of  the patients with primary chronic osteomyelitis [4].    The osteoradionecrosis is a side effect in the therapy of  malignant diseases to the head and neck area with ionizing  radiation.    Osteoradionecrosis describes the exposed necrotic bone due  to radiation. The infected osteoradionecrosis describes the  additional infection of the necrotic bone [7].    The prevalence of osteoradionecrosis ranges from 0 to 23%  of the patients with head and neck radiation [8]. Usually,  older patients are affected (60 years +10 years) since the pri-  mary disease causing the head and neck radiation are dis-  eases in patients with advanced age [9]. Men are affected  more than twice as often [9].    The etiology of the osteoradionecrosis is radiation therapy to  the head and neck area. Usually, another trigger is required  in the development of the osteoradionecrosis (see  pathogenesis).    Due to the radiation therapy, the vessels of the bone change  and become hyalinized. It results in a lack of nutrition and  hypoxia with the subsequent death of osteocytes [7]. This  seems to be more likely in radiation doses above 40-50 Gy  [10]. The radiation has additional side effects to all tissues  being in the radiation field including the skin, the muscles,  and the salivary glands. Due to the resulting xerostomia radi-  ation, caries develops so that an osteoradionecrosis might  develop.   The osteonecrosis occurs more often in the mandible  most probably to the greater extent of cortical bone and the  more critical vascularization of the mandible. And the man-  dible most probably is more often in the radiation field due to  the location of the primary tumor [10].   There are several risk factors that are associated with a  more frequent occurrence of the osteoradionecrosis. Those    are male gender, insufficient oral hygiene, pressure denture  sores, a tumor localized in the tongue, alveolar process of  the mandible, the floor of the mouth, and retromolar as well  as persisting alcohol and nicotine consumption. Next to  these, there are therapy-linked risk factors, namely a tumor  resection including resection of the bone and dentoalveolar  surgery performed in timely proximity to the radiation ther-  apy [10].    It is mainly differed between the aseptic osteoradionecrosis  and the infected osteoradionecrosis. Another very common  staging system uses the potential benefit of a rather contro-  versially discussed therapy option the hyperbaric oxygen  treatment and therefore won’t be discussed in further detail.    The lacunae of the osteocytes in osteoradionecrotic bone are  empty (Fig. 22.3). There is a lack of osteoblastic rimming  and the Haversian and Volkmann canals do not harbor any  blood vessels. The marrow of the bone shows acellular col-  lagen. The periosteum is acellular and avascular [5].    Fig. 22.3. The examination of the osteoradionecrosis under the micro-  scope shows avital bone with irregular fissured borders. The lacunae of  the osteocytes are empty without osteocyte cell nuclei (black arrows)  and also the blood vessels in the Haversian canals have undergone  necrosis, so that only empty spaces are the visible remnants (yellow  arrow). The necrotic bone is missing the osteoblastic rimming (green  arrow). The bone marrow is replaced by a collagen fiber-rich scar like  connective tissue (red arrow)    Symptoms are the exposed necrotic bone that can be visible  or palpable with a probe. Further symptoms are pain, swell-  ing, the development of granulation tissue, foetor ex ore, oral  and extraoral fistulas, potentially increased mobility of the  adjacent teeth, altered sensibility, and occlusion [10].    Main complications are extended infections of the site, the  development of fistulas, and pathological fractures. This  might result in resections of the altered bone including the  loss of the continuity of the bone or the opening of the nasal  cavity or sinus. This results in a reduced masticatory func-  tion. Due to the fibrosis of the soft tissues, trismus might  occur. All these factors lead to a reduced quality of life [10].    The diagnosis is a clinical one. There needs to be a manda-  tory head and neck radiation and the exposed necrotic bone.   Typical radiologic findings are bone destruction, altered  bone density, the occurrence of sequestra, and pathological  fractures.    Differential diagnoses are osteomyelitis and the medication-  associated osteonecrosis of the jaws as well as the existence  of malignancy so that a histological sample should be  assessed.    As already mentioned, the evidence of the use of hyperbaric  oxygen treatment is rather low and is not recommended [11,  12]. Smaller necrotic areas can be treated conservatively  using antiseptic mouth rinses, antibiotics, and pain killers. In  some cases, a wait and see strategy is reasonable. Sometimes  circumscribed debridement might be performed. Extended  necrotic areas should be surgically removed [13]. The aim is  to preserve damage to the alveolar nerve and to avoid a con-  tinuity defect of the mandible. The operation should be as  atraumatic as possible. The periosteum should not be  removed if possible. The necrotic areas should be removed,  sharp edges need to be smoothened, and the bone should be  covered with soft tissue. The surgery should be performed  with perioperative antimicrobial therapy.    The risk for a recurrence of an osteoradionecrosis is high.  Pressure denture sores, wound healing deficiencies, and  mucositis are risk factors for a recurrence.    A 3D-planning of radiation therapy might help to reduce the  radiation doses in the bone. In addition, a splint inserted in  the patient’s mouth during the radiation might help to reduce  the burst of the local mucosal membranes due to secondary  radiation that might occur due to metallic dental restorations.  An additional splint to provide fluorides to strengthen the  teeth might help prevent the development of radiation  caries.   It is feasible to reduce the existence of risk factors that  might later on trigger the development of an osteoradione-  crosis. Therefore, an initial dental checkup and therapy  preceding the radiation therapy should be performed  including the extraction of all non-restorable teeth. The  patient should be motivated for exceptional good oral  hygiene [10].    There are several pharmaceutical agents that cause osteone-  crosis of the jaws. In the following, the main focus will be on  the bisphosphonate-associated osteonecrosis.   Bisphosphonates are used in patients with an increased  osteoclastic activity due to malignancy such as solid tumors  with osseous metastases or the multiple myeloma or due to  metabolic bone diseases such as osteoporosis. The main tar-  get of bisphosphonates that can be administered orally of IV  is the osteoclasts.   Bisphosphonates are classified into nitrogen- and non-  nitrogen-containing bisphosphonates. The non-nitrogen-  containing bisphosphonates are built into ATP and can no  longer be used as a source of energy in the cells. The  nitrogen-containing bisphosphonates inhibit the farnesyl  pyrophosphate synthase in the mevalonate pathway leading  to decreased osteoclastic function [14]. In 2003, the  bisphosphonate-associated osteonecrosis was first men-  tioned in a scientific paper [15].    22.4.1.2 Definition  The bisphosphonate-associated osteonecrosis is defined as the  occurrence of the necrotic bone of the jaws that has been per-  sistent for at least 8 weeks with a current or previous history of  bisphosphonate use (Fig. 22.4). Furthermore, it is demanded  that the patient had had no former head and neck radiation [16].  The last demand seems arbitrary since the coexistence of  a further risk factor simply increases the risk of osteonecro-  sis development so that there is a special risk constellation.  There is evidence that it is even possible to histologically  distinguish an osteonecrosis derived from bisphosphonates  compared to osteoradionecrosis [17].   The prevalence and incidence of the bisphosphonate-  associated osteonecrosis of the jaws depend on the primary  disease, comedication, and the existence of local trigger fac-  tors. The highest risk is present in oncologic patients with    Fig. 22.4 Huge bisphosphonate-associated osteonecrosis of the left  maxilla in a patient with non-Hodgkin lymphoma and a zoledronate  treatment for 2.5 years before a pressure denture sore triggered the  osteonecrosis    further compromising medications. Incidences for patients  with malignant diseases range from | to 20% [18-20]. The  prevalence of secondary osteoporosis is about 1% and for  primary osteoporosis 0.1% [21]. There is only a small differ-  ence between the genders. Women are affected a little bit  more often than men. Most probably due to the osteoporosis  and breast cancer cases vs. the prostate cancer cases that  exclusively occur in men. The average age is approximately  60 years +10 years (standard deviation) [9].   The main factor is the use of nitrogen-containing bisphos-  phonates. Administered bisphosphonates will be incorpo-  rated in the bone. It is unclear if and how long these  bisphosphonates are active. The development of  bisphosphonate-associated osteonecrosis can be triggered by  oral factors—this is usually a wound in the oral cavity: peri-  odontal disease, surgical procedures, etc. [9, 22].   The main target of the bisphosphonates is the osteoclast,  thereby inducing reduced bone remodeling. Due to the unspe-  cific interaction with cells, not only the osteoclasts are affected,  but also, in lower concentrations, osteoblasts are stimulated  [23]. The effect is an increase in total bone. Other affected cell  lines are blood vessel cells, fibroblasts, and keratinocytes. The  antiangiogenic function of bisphosphonates [24, 25] leads to  decreased vascular exploitation [26]. This results in fewer  potentially less potent vessels that have to support more bone.  In addition, the soft tissues covering the bone are affected by  the bisphosphonates so that potential wounds are less prone to  heal [24]. In older articles, it is often described that tooth  extractions are responsible for the development of the bisphos-  phonate-associated osteonecrosis of the jaws. This theory  might not be right. It is more likely that these teeth have been  extracted too late since they were extracted out of an already-  existing, altered, infected, or necrotic bone [27].   The bisphosphonate-associated osteonecrosis of the jaws is  classified into several different stages. At-risk patients are all  those receiving bisphosphonates.    Stage 0 patients are patients that do have some symp-  toms without any visible uncovered bone.   Stage I, the necrotic bone becomes visible. Patients in  this stage usually do not have any symptoms.   Stage III, further complications occur such as necrotic  areas involving the base of the mandible or the sinus or  pathologic fractures are existent [16].   Usually, there is a mucosal damage above the necrosis, per-  haps some granulation tissue (Fig. 22.5). The necrotic bone  is often avascular and covered in bacteria, especially  Actinomyces (Fig. 22.6) [28]. The osteonecrotic bone has    Fig. 22.5 In this case, the bone necrosis is induced by bisphospho-  nates. Besides necrotic bone showing empty osteocyte lacunes (yellow  arrow), inflammatory cellular infiltrate can be seen in the medullary  cavity (black arrows). It is mainly composed of lymphocytes, neutro-  phil granulocytes, and also plasma cells. Here, signs of the bone remod-  eling are also visible. The dark line within the bone, the border of the  periosteum before necrosis (red arrow) separates necrotic bone in the  center from the new-built bone with a lining of active osteoblasts (blue  arrow) on the outside    Fig. 22.6 Actinomyces species (green arrow) frequently can be found  next to necrotic bone (yellow arrow) in the jaws. Dense clouds of bac-  teria affecting the bone leading to deep excavations of the necrotic  bone. An inflammatory infiltrate of neutrophil granulocytes and macro-  phages in fibrin-rich exudate fills the bone marrow (black arrows) as a  border which limits bacterial growth    parts with empty osteocytic lacunae next to viable osteocytes  so that there are necrotic areas of the bone that harbor parts  of the viable bone. Inflammatory infiltrates are seen in nearly  all cases consisting of granulocytes and lymphocytes. The  obliteration of mainly the segmental arteries is not existent in  every case [28]. The periosteum is usually viable [5].   The classical symptoms are the visible necrotic bone and  pain in case of an additional infection of the bone so that the  symptoms are very unspecific.    22.4.1.9 Complications  The typical complications are the progress of the initial small  necrosis so that big parts of the bone might be affected by the  osteonecrosis. Since the bone is no longer covered with soft  tissue, an additive infection can cause typical symptoms and  leads to a shift to a different stage of the osteonecrosis. Major  complications are the loss of the integrity of the bone and  extraoral fistulas or abscesses.   The quality of life might essentially get affected in patients  with medication-related osteonecrosis of the jaws [29].   The diagnosis is primarily a clinical one if all criteria are  fulfilled (see definition). Unfortunately, there is no sensitive  radiological tool that shows neither the exact location of the  osteonecrosis nor the extent of the necrosis [30]. Once there  is a destruction of the bone due to the infection, changes can  be seen in the radiologic pictures. But these changes are not  specific for the changes (Figs. 22.7 and 22.8a, b). There is  evidence that the potential osteonecrosis can be detected at a  very early stage via scintigraphs [31].   Regarding the clinical picture, osteomyelitis and osteoradio-  necrosis are the other typical potential diagnoses. In addi-  tion, malignant diseases should be ruled out, especially the  ones why the bisphosphonates were given in the first place,  e.g., breast cancer or prostate cancer.   The osteonecroses should be treated since the lack of treat-  ment usually ends in the progression with more extended  areas of necrotic bone and a potential switch in the stage of  the osteonecrosis.   There are several approaches in the therapy of the  bisphosphonate-associated osteonecrosis of the jaws.  Smaller osteonecroses can be treated conservatively or with  a moderate surgical intervention. Perioperative antibiotic  treatment should be initiated. After the debridement or resec-  tion of the necrotic bone, a plastic coverage of the bone  should be performed.    Fig. 22.7 This is the same  patient as seen in picture 4.  There are nearly no changes  visible that indicate the  existence of osteonecrosis. A  very typical change that can  be seen is the thickened and  sclerotic lamina dura in the  mandible and the honeycomb  pattern of the bone due to the  sclerotic trabeculae of the  bone    Fig. 22.8 Two slices from a cone beam CT from a patient with a  malignant primary disease and bisphosphonate intake. (a) Axial slice  from a patient with osteonecrosis of the left and the right mandible. On  the right-hand side, a thickening of the cortical bone can be observed  and sclerosis of the cancellous bone. On the left-hand side, the perios-    Extended or multiple osteonecrotic areas should be resected.  This might include an inpatient setting with the postoperative  use of a nasogastric tube and antibiotic iv treatment [32].    22.4.1.13 Prognosis  The recurrence rate of the osteonecrosis depends on the  mode of therapy and is the lowest for surgical interventions    teal reaction is visible. (b) Coronal slice with a periapical translucency  of the molar on the right-hand side as a potential trigger of the osteone-  crosis that reached the level of the alveolar nerve canal. On the vestibu-  lar side of the left mandible the periosteal reaction can be seen    and the highest for purely conservative treatments. In the lat-  ter case, complete closure of the mucosal membrane cannot  always be achieved [32].    after the course of bisphosphonate therapy. Since the  bisphosphonate-associated osteonecrosis of the jaws is usu-  ally triggered by an oral wound, potential dental foci should  be eliminated before the start of bisphosphonate therapy  [32].   If surgery needs to be performed in patients with bisphos-  phonate therapy, anti-microbiological prophylaxis should be  performed [32].    22.4.2 Osteonecrosis of the Jaws Due to Other  Medications but Bisphosphonates    There are other medications that can cause osteonecrosis of  the jaws. The definition is the same compared to the osteone-  crosis due to bisphosphonates.   The most frequent osteonecroses can be observed in patients  with denosumab that is administered in the same patients  that receive bisphosphonates. The definition, etiology, clas-  sification, symptoms, complications, diagnoses, differential  diagnoses, therapy, prognosis, and prevention are the same  or similar to the ones of the bisphosphonate-associated  osteonecrosis of the jaws.   The pathogenesis might be different since denosumab  only affects the RANK/RANKL/OPG mechanism that is  predominant in the communication between osteoblasts and  osteoclasts. Therefore, an impact on the soft tissues includ-  ing the vessels seems unlikely so that the likewise reduced  bone remodeling seems to be the major component in the  development of the denosumab-associated osteonecrosis of  the jaws.   Sunitinib is an inhibitor of a tyrosine kinase and therefore  has a less specific mode of action. It is given in patients with  gastrointestinal cancers, renal cell carcinoma, and pancreatic  neuroendocrine tumors [33]. A side effect in the use of suni-  tinib is the development of osteonecroses of the jaws [34].    22.4.2.3 Imatinib  Imatinib is another tyrosine kinase inhibitor. Osteonecrosis  in imatinib-only use has been described [35].   Bevazicumab is a vascular endothelial growth factor-  (VEGF-) inhibitor and is used in several oncologic treatment  concepts, e.g., breast cancer, colorectal cancer, and lung can-  cer. Several cases of osteonecroses of the jaws have been  described [36, 37].   Ziv-aflibercept is a recombinant vascular endothelial growth  factor- (VEGF-) receptor. Several cases of the development  of osteonecroses of the jaws have been described in patients  that did not receive any of the other typical medications  causing osteonecrosis [38]. In the pathogenesis, the antian-  giogenic factor might be the reason for the development of  the osteonecrosis.   Everolimus is a mammalian Target of Rapamycin (mTOR)  inhibitor. It is used in several oncologic diseases and was  associated with the development of osteonecroses in the jaws  [39].    22.4.2.7. Corticosteroids  There is evidence that the use of corticosteroids increases the  risk of osteonecrosis development of the jaws [40]. The fem-  oral head osteonecrosis has been described in patients with  long-term corticosteroid use [41].   It should be stated that the use of several of these agents  in combination might further increase the risk of osteonecro-  sis development.   Next to therapeutically used agents, some drugs are respon-  sible for the development of osteonecroses. Crystal Meth is  the crystalline form of methamphetamine hydrochloride. It  functions as a sympathomimetic and has a very high poten-  tial for abuse and dependency. One side effect is the meth  mouth with serious tooth and damage to the oral cavity  including the development of osteonecroses [42]. 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Open Access _ This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.  org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropri-  ate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.   The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in  a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.   Sinusitis, also known as rhinosinusitis with the association  of rhinitis, is acommon presentation within the primary care  setting, due to the effect it can have on individuals’ quality of  life. It is defined as the inflammation of the mucosal lining in  at least one of the paranasal sinuses with an acute presenta-  tion lasting for less than 12 weeks and chronic extending to  durations greater than this. The maxillary sinus is the largest  of four paranasal sinuses and, with its close relationship to  the underlying dentition, it is often susceptible to inflamma-  tory processes. This chapter explores the anatomy, physiol-  ogy of the maxillary sinus, the aetiology, assessment and  management of maxillary sinusitis.    The maxillary sinus is the largest of the paranasal sinuses and  develops during day 65-75 of gestation, with a volume of  approximately | cm? at birth. Up untill an average age of 12,  pneumatisation of the maxillary sinus continues as the space  occupied by tooth germs is freed through their eruption [1]. In  the latter stages of development, it pneumatises inferiorly,  guided by the eruption pathway of the permanent dentition.  The main function of the maxillary sinus is involved in the  humidification and warming of inspired air as well as preven-  tion of microorganism ingress through mucociliary action. In  addition to this, the paranasal sinus contributes to voice reso-    K. Ganesan   Department of Oral and Maxillofacial Surgery, Southend  University Hospitals NHS Trust, Southend-on-Sea, UK    © The Association of Oral and Maxillofacial Surgeons of India 2021    nance. A possible evolutionary function may also be as a ‘crum-  ple zone’ during trauma, thus protecting the brain (Fig. 23.1).  In an adult, the maxillary sinus takes the form of a quad-  rangle pyramidal shape, with the base adjacent to the nasal cav-  ity and the peak extending towards the zygomatic process, and  a volume in the region of 15 cm*. The roof of the sinus is  formed of the orbital floor in the centre of which runs the infra-  orbital neurovascular bundle. The anterior wall of the maxillary  sinus is the weakest of the walls, with the thinnest section supe-  rior to the canine resulting in the canine fossa. It is also perfo-  rated by the infraorbital nerve that supplies the maxillary sinus,  along with the greater palatine nerve. The posterior wall of the  sinus lies in front of and shelters the internal maxillary artery,  sphenopalatine artery, Vidian canal and the greater palatine  nerve. The inferior wall is the most varying in shape, with  invaginations corresponding to the alveolar bone of the max-  illa; the anatomical root structures of maxillary molars and the  hard palate. The bone separating the dental roots can be varying    Fig. 23.1 Schematic diagram of the maxillary sinus with representa-  tion of the geometric shape of the cavity    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1-15-1346-6_23    in its quantity; from complete absence to thicknesses of up to  12 mm [2]. This close proximity is a contributing factor towards  the likelihood of dental iatrogenic and inflammatory pathology  presenting in the maxillary sinus. The medial wall that is paral-  lel to the nasal cavity communicates with it through the natural  sinus ostium at the postero-superior aspect of sinus. This  ostium opens in to a triangular space of approximately 15 mm?  diameter formed by the uncinate process medially, the lamina  papyracea laterally and the ethmoidal bulla posteriorly before    Fig. 23.2 Schematic diagram showing a coronal cross section of the  maxillary sinus and the osteomeatal complex    Fig. 23.3 Schematic diagram  with a sagittal cross section of  the nasal cavity and the  respective openings in to it    Opening of  nasolacrimal duct  ©Association of Oral and Maxillofacial Surgeons of India    communicating with the nasal cavity through a semilunar hia-  tus in the middle meatus. This is an area of common drainage  from the maxillary, anterior ethmoidal and frontal sinuses.  Some individuals may exhibit anterior/posterior fontanelles;  bony dehiscences inferior to this, covered with mucosa. These  can act as accessory ostia, points of drainage when the main  osteomeatal complex is blocked or there is a change in sinus  pressure. An osteomeatal complex (OMC) is an important  functional unit and is also a key area for the pathogenesis of  chronic rhinosinusitis. It consists of multiple bony structures,  air spaces and ostia. The bony structures include the middle  turbinate, uncinate process of the ethmoid and bulla of the eth-  moid. Air spaces are formed by the frontal recess, infundibu-  lum of the ethmoid and the middle meatus. Ostia consists of  anterior ethmoid, maxillary and frontal sinuses. The classic  OMC as mentioned above has been described as the anterior  osteomeatal unit. The sphenoethmoidal recess and the superior  meatus are referred to as the posterior meatal unit (Fig. 23.2).   Maxillry sinus septa, present in approximately 28.4% of  cases [3], are thin projections of cortical bone that divide the  sinus into more than one compartment either in the transverse,  sagittal or horizontal plane, usually in the region of the first or  second molar.   Smaller air-filled compartments in the periphery of the max-  illary sinus can include Haler cells and Concha bullosa. Haller  cells are air cavities encompassed in the ethmoidal capsule and  are located below the inferomedial aspect of the orbital floor,  and lateral to the ethmoidal cells. These can be present in a  range of sizes as well as unilaterally or bilaterally. Concha bul-  losa is another variant air-filled cavity pneumatised in to the  middle turbinate. These particular anatomical (Fig. 23.3) varia-    Fig. 23.4 Schematic diagram  of the secretary and clearance  of the mucous via the  mucociliary cells    tions have the potential to influence the dimensions of the osteo-  meatal complex, increasing the likelihood of sinus disease [4] .    At a histological level, the maxillary sinus consists of cili-  ated columnar cells, basal cells and goblet cells and thus  forming respiratory epithelium architecture. Unlike the rest  of the respiratory pathway, the sinuses have fewer ciliated  and goblet cells; friable epithelium and fewer seromucous  cells, making them prone to microorganism ingress and  related pathology.   The clearance of secretions from the sinuses is through  a combination of ciliary and mucous action. The mucous  secreted by the goblet cells consists of 96% water, with  the rest consisting of glycoproteins, immunoglobulins,  histamines, lactoferrin, prostaglandins and lysozymes [5].  It functions to trap foreign body and defend against bacte-  rial ingress. This is combined with the ciliary action that  promotes a spiral action of movement of the mucous  through active transport from the base of the sinus towards  the natural ostium in the supero-posterior aspect of the  medial sinus wall and thus working against the forces of  gravity.   Normal flora within the maxillary sinus is usually a com-  bination of sterile aerobic and anaerobic organisms includ-  ing bacteria organised in a complex biofilm within the sinus  mucus layer. These usually include mainly aerobic  B-hemolytic streptococci, staphylococci and haemophilus  spp. The anaerobic organisms, that are fewer in quantity,  include peptostreptococcus, fusobacterium sp and bacteroi-  des. Whether these organisms are present in normal physiol-    ogy or transiently is poorly understood. Host specific and  non-specific defence against these bacterial species is also  part of normal physiology with the sinus mucosa producing  secretion including antimicrobial peptides, proteins, neutro-  phils, macrophages coupled with the mucociliary transport  towards the ostium (Fig. 23.4).    Due to the narrow size of the ostium opening, occlusion and  related pathology of the maxillary sinus space are very likely  possibilities. Obstruction of the sinus ostium can either be  primary to the sinusitis process or secondary inflammation  originating from elsewhere in the sinus.   With obstruction of the natural ostium, there is reduced  oxygenation and gas exchange within the maxillary sinus,  alongside reduced mucociliary action and mucous stasis. In  the most common acute form of sinusitis, viral upper respira-  tory tract infections result in significant nasal congestion that  results in maxillary sinus blockage and stasis. Anatomical  differences such as large middle turbinates, deviated nasal  septums or concha bullosa can increase the likelihood of  ostium occlusion. Polyps, in particular those originating  from the ethmoid, may also obstruct the maxillary sinus  opening (Table 23.1).   Any form of obstruction and subsequent stasis in the max-  illary sinus produce a favourable environment for the flour-  ishing of an anaerobic environment, encouraging the  formation of purulent secretions. In addition to this, changes  in the sinus pressure, coupled with local mucosal inflamma-  tion, contribute to the symptoms of pain and pressure in the  region [6]. The initial lower sinus pressure is caused by the    Movement of the fluid  out of the blood vessels  causing congestion (soft    consumption of the finite oxygen within the blocked and  confined maxillary sinus cavity. This is followed by a tran-  sient increase in pressure where there is a greater production  of carbon dioxide and sinus secretion.   Chronic rhinosinusitis has features of long-term inflamma-  tion, rather than primary infection, of the nasal passages and  paranasal sinuses with an unknown underlying cause. It is  likely to be part of a cycle involving inflammation, infection  and subsequent obstruction of the ostium [7]. Without the pres-  ence of polyps, chronic sinusitis may be multi-factorial in  nature, with one or several predisposing factors as outlined  below.   Nasal polyps are oedematous masses of the mucosal  membrane found in the nasal passages and paranasal sinuses.  Histologically, they show squamous epithelial proliferation,  a thickened basement membrane, absence of neurosensory    filaments and inflammatory cell infiltrate with high numbers  of oesinophils [8]. The pathogenesis in the formation of pol-  yps and its contribution towards chronic rhinosinusitis is  poorly understood. One in vivo study involving rabbits with  stimulated maxillary sinusitis observed the formation of  inflammatory-type polyps in subjects with purulent infection  and granulation based polyps in both purulent and non-  purulent infections. In both infective processes, epithelial  damage to the mucosal lining appeared to be a significant  factor in the initiation of polyp formation [9]. Other evidence  shows that high levels of interleukin 5, 13 and histamines in  the polypoid tissue may also have a contributing role [10].  The general consensus of studies shows a high level of  inflammatory mediators in the initiation and presence of  nasal polyps, suggesting chronic inflammation to be a key  factor.    The polymicrobial nature of maxillary sinusitis has been  well documented. The initial aerobic bacterial infective  organisms often include Streptococcus  Haemophilus influenzae and Moraxella catarrhalis in acute  sinusitis [11]. Chronic sinusitis has found to harbour the  aforementioned organisms in addition to Prevotella species,  Fusobacterium species and anaerobic streptococci [12].  More recent studies have cultured Staphylococcus aureus, in  particular methicillin resistant-type from sinus mucosal sam-  ples [13].    Any variation deemed to alter the volume or the size of the  maxillary ostium may contribute to an increase risk of sinus-  itis. This includes [14]:    The distinct relationship between the allergy and inflamma-  tion remains unclear. Current hypothesis predicts that with  the ventilation passage in continuum with the nasal mucosa,  inflammation along the rest of the airway can affect the nasal  passages, thus causing narrowing of the ostium. This is sup-  ported by the high incidence of chronic rhinosinusitis with  allergies driven by IgE mediators.    The association between chronic sinusitis, mainly with nasal  polyps, and asthma has been well documented. Several stud-  ies have shown radiographic sinus mucosal abnormalities in  individuals with asthma, in particular with those suffering  from severe steroid-dependent asthma [15]. Similar studies  show a trend in the severity of sinusitis correlating to the  severity of asthma experienced, supporting the theory of  inflammation of a unified mucosal airway concept of the dis-    ease process. The association between asthma and sinusitis  is further indicated with studies showing individuals report-  ing improvement in their asthma symptoms subsequent to  medical and/or surgical treatment of their sinusitis [16].    Aspirin/NSAID hypersensitivity has been found to have an  association with a persistent form of chronic sinusitis, usu-  ally with the presence of nasal polyps. Along with severe  asthma, this disease process has been named the ‘Aspirin-  triad’. The mechanism of pathogenicity is thought to be  linked to cyclooxygenase inhibition and inhibition of arach-  noid acid metabolism rather than an underlying immunologi-  cal process. The presence of hyperplastic sinus mucosa  contributes to a high level of recurrence in nasal polyps sub-  sequent to sinus surgery for removal [14].    Several environmental factors have been associated with an  increased incidence of sinusitis with changes in air quality  acting as suggestive stimulants. Greater prevalence has been  identified in patients exposed to chemical air pollutants  including pharmaceutical products, photocopying ink by-  products, smoke and dampness [14, 17].    This may be present in the form of reduced cilia or ciliary  cells, causing impairment of mucociliary flow and thus cre-  ating environments favourable for bacterial or viral  sinusitis.    Smoking is likely to diminish the presence of normal  microbiological flora in the nasal and paranasal spaces,  allowing for the growth of pathogenic microorganisms and  thus eliciting a hypersensitivity reaction in the sinonasal  mucosa [14].    It has been suggested that inflammation may be elicited  when the oro- and nasopharynx comes in contact with gastric  acids during reflux and subsequently contributing to sinusitis  [18].    As part of the examination process, this should be evaluated  at the early stages and could prevent prolonged periods of  investigations and symptomatic management (Fig. 23.5).  Approximately 15-24% of unilateral maxillary sinusitis cases  are believed to be of odontogenic origin [19], with some stud-  ies indicating this figure to be as high as 40% [20]. In a meta-  analysis of 15 observational review studies consisting 770  cases, the first molars were found to be the most common  tooth to be causative for odontogenic sinusitis (22.51%), fol-  lowed by third molars (17.21%), second molars (3.97%), pre-  molars (5.96%) and lastly canines (0.66%). The etiological  contribution to the sinusitis was found most commonly to be  from iatrogenic factors (55.97%), periodontal disease  (40.38%) and odontogenic cysts (6.66%) [21]. Figure 23.6  outlines the distribution of the iatrogenic processes leading to  sinusitis [21].   The disruption in maxillary sinus floor, from whichever  odontogenic source, causes localised inflammation that  remains persistent in that area or spreads along the sinomuco-  sal surface with subsequent obstruction of the sinus ostium.  Bacterial colonisation have been shown to consist of both  aerobic and anaerobic species in 75% of cases, with the other  25% predominantly anaerobic in nature. Staphylococcus  aureus and streptococcus pneumonia were the predominant  aerobic bacteria isolated. When looking at the anaerobic bac-  teria distribution, Peptococcus and Prevotella species domi-  nated and haemophilus and Moraxella species were absent in  cases of odontogenic maxillary sinusitis [20].    Fig. 23.5 (a) A coronal section of a CT of maxillary sinus showing  extensive left-sided maxillary sinusitis. A periapical radiolucency on  the upper left first molar with a breach in the cystic area to allow the pus    Sinusitis is defined as an inflammation of the paranasal  sinus mucosal lining; however, it rarely presents in isola-  tion and is usually coupled with the inflammation of the  nasal mucosa, thus being termed as rhinosinusitis. The car-  dinal features, of which two are required for a suggestive  diagnosis of a rhinosinusitis, are outlined in the 2012  European position paper by the International Rhinology  Society (Table 23.2). The condition is broadly classified  based upon the chronicity of the condition as well as  whether there is presence of polyps.    Acute rhinosinusitis (ARS) is defined as persistent sinusitis  that resolves within a 12-week period. It is a common pre-  sentation within the populations globally, with prevalence  rates between 6 and 15% [14].    Chronic rhinosinusitis is defined by the persistence of sinus-  itis symptoms for greater than 12 weeks, with no resolution  after initial sinusitis treatment. It is further subdivided into  whether there is a clinical and radiographic presentation of  nasal polyps.    to enter the sinus and causing the sinusitis. (b) A sagittal section same  image showing the extent of the sinusitis. A periapical radiolucency is  noticeable in relation to mesiobuccal root of upper left first molar    Fig. 23.6 A pie chart  illustrating a distribution of  the iatrogenic processes    4. Eosinophilic mucin that does not invade into sinus  tissue.  5. Characteristic CT radiopaque sinus findings.    The predicted pathogenesis of AFRS is believed to be an  allergic, immediate hypersensitivity reaction to an inhaled  fungal organism resulting in a chronic inflammatory response  in a predisposed individual, usually with asthma. The most  common isolated fungal species include Bipolaris,  Curvularia, Aspergillus, and Drechslera species.   Fungal balls are non-invasive, dense collections of fungal  debris within the maxillary sinus. Found in mostly immuno-  compromised and elderly individuals, they are formed com-  monly of aspergillus, in response to prolonged exposure to  the fungi through inhalation of airborne spores or oral antral  communication.   Acute invasive fungal sinusitis is a rapidly infiltrating  growth of the fungi with a high risk of morbidity and mortal-  ity. Immunocompromised individuals that are predisposed to  this include those with:    Initial clinical presentation involves an acute onset of  facial/head pain, fever, epistaxis and, in severe cases, of bony  erosion with extrasinus infiltration and possible mental sta-  tus change. Urgent surgical management and post-operative  antifungal therapy is required.    Diagnosis of sinusitis is primarily through clinical history  and examination with the possible adjuncts of imaging stud-  ies and/or laboratory testing. The signs and symptoms of  sinusitis can be categorised in to major and minor. Major  features include infraorbital and maxillary facial pain, pres-  sure sensation, congestion/obstruction sensation, purulent  rhinorrhoea, hyposmia and fever [23]. Minor features are  present in some of the individuals with suspected sinusitis  and include headache, fatigue, dental pain, halitosis, cough  and ear pain/fullness.   The acute form of rhinosinusitis is indicated usually when  a patient has recently suffered with the symptoms of an upper  respiratory tract infection that is viral in nature. After an ini-  tial 7-10 day phase of viral infection with gradual recovery,  patients give history of worsening symptoms. Evaluation of  nasal discharges show secretions that were once clear at the    at the initial stages of the viral infection that become yellow,  green or grey in nature at the latter aspect of the biphasic  disease process. Unilateral disease process provides greater  indication towards sinusitis. Palpation over the infraorbital  sinus region would elicit tenderness due to the pressure  build-up from stasis and inflammation of the sinus cavity.   Patients with suspected chronic rhinosinusitis may pres-  ent with symptoms of acute rhinosinusitis but to a milder  degree, with the absence of a predisposing upper respiratory  tract infection including fever. The presenting complaint  may often be of the lack of effectiveness in acute medical  management techniques [24]. Regardless of whether the  causative factor in the chronicity of their sinusitis is from the  presence of nasal polyps or not, patients will often present  with facial pain or pressure, anterior or posterior nasal dis-  charge and slight fatigue. Those that suffer from chronic  sinusitis without the presence of polyps may also experience  anosmia or hyposmia. Thus, the ambiguity in presentation  makes the diagnosis of chronic sinusitis with clinical history  and examination alone challenging, but nonetheless provide  a vital role in their diagnosis and long-term management.   Endonasal examination in the form of anterior rhinoscopy  may also be performed with headlighting and a speculum;  alternatively with the large speculum of an otoscope. It can  play a supportive role in visualising inflamed nasal mucosa,  presence and quality of nasal discharge and the turbinates  with an indication of nasal polyps or anatomical variation  that may not have been suspected previously.   Nasal endoscopy provides an enhanced technique for  direct visualisation of the nasal passage. Abnormalities in the  nasal passage can be seen including the middle, superior tur-  binates and the osteomeatal mucociliary drainage passage.  Where acute rhinosinusitis is diagnosed mainly through clin-  ical history and simple examination, this method is more rel-  evant for incidences of chronic rhinosinusitis. Nasal  endoscopy can be used at 3, 6, 9 and 12 monthly intervals in  chronic disease process to assess the degree of inflammation,  discharge and size of nasal polyps.   Intraoral assessment should include assessment of both  soft and hard tissues. The dentition requires close evaluation  to rule out primary aetiology which can account for 5—10%  of acute rhinosinusitis cases [25]. Detailed assessment for  extensive dental caries, periapical and/or periodontal infec-  tions for teeth distal to the canine is required. Where multiple  teeth are unilaterally tender to percussion with a lack of cor-  relation to dental pathology clinically or radiographically,  sinusitis not of dental cause is a probable diagnosis. This  sensation may also be elicited with facial or head move-  ments. This is due to the close neural relationship between  the maxillary sinus and upper molars. Pain or pressure sensa-  tion is also elicited from palpation in the most superior aspect  of the maxillary buccal sulcus. In some cases, posterior dis-  charge in to the nasopharynx that is either characteristically    clear or coloured in nature can be visualised during intraoral  assessment.   Recurring episodes of acute rhinosinusitis (more than  three episodes a year) requires wider consideration of the  primary causative factor. Peters et al. has attributed recurrent  acute rhinosinusitis to various reasons such as immunodefi-  ciency, cystic fibrosis, ciliary dysfunction and anatomic  abnormalities [16] (Table 23.3).   Severe episodes of acute rhinosinusitis originating from  the maxillary sinuses are a rare presentation. Complications  can arise with the involvement of the ethmoidal and frontal  sinuses that are in close proximity to vital structures includ-  ing the anterior cranial cavity and the orbits with associated  venous drainage systems [27].   As per Ah- See et al. [28], certain features of sinusitis that  require urgent intervention are:    Clinical imaging is a useful adjunct to the diagnosis of sinus-  itis. It can provide confirmatory and characteristic informa-  tion to guide management of the condition.   Plain radiography is an accessible and cost-effective  means of visualising the maxillary sinus. An orthopantomo-  gram (OPG), though focusing on the dentition, maxilla and  mandible, also includes a significant proportion of the maxil-  lary sinuses and provides an opportunity to identify the pres-  ence of pathological features. Indication of sinusitis would  be from the presence of unilateral or bilateral generalised  diffuse radiopacity within the maxillary sinus. Causative dis-  ease process can also be visualised including the proximity  of periapical pathology from the maxillary dentition, peri-  odontal disease, cystic lesions of dental origin, foreign body  presence, sinonasal mucocele or polyps. The significant level    of artefact from overlying structures however limits the use-  fulness of this imaging modality. Where dental disease is a  suspected contributing factor, dental periapical radiographs  can be considered for a targeted and enhanced dental evalua-  tion. Consequently, a dental cause for sinusitis can be chal-  lenging to diagnose, in particular in cases of chronic  sinusitis.   The occipitomental view, also known as the ‘Water’s  view, can additionally offer visualisation of the entire sinus  as well as other paranasal sinuses, with fluid collection and  mucosal thickening evident at varying angles. Care must be  taken to differentiate between a benign mucosal cyst and a  fluid level. A diagram showing the difference in the appear-  ances between the two is shown in Fig. 23.7.   Despite the efficiency with which these images can be  taken, one should consider whether the overall information  gained for sinusitis diagnosis justifies the exposure to radia-  tion. Plain imaging does not offer a comprehensive view of  the maxillary sinus ostium, the occlusion of which will often  be the causation of subsequent sinusitis. Apart from sugges-  tion in the presence or absence of disease process, it does not  offer information on the severity of the condition. With sig-  nificant overlap, diagnosis of sinus masses can also be  difficult.   Computer tomography (CT) (Fig. 23.8) offers the three-  dimensional visualisation of the sinuses and can be confirma-  tory in the presence or absence of sinus disease. These should  be considered only where a patient’s symptoms are vague or  first-line medical management has thus far failed to offer sig-  nificant relief of symptoms. Contrast medium is not required  as they do not offer additional value towards diagnosis or man-  agement. It should also be noted that where CT scans of  sinuses are taken, maxillary teeth should also be included to  assess for their involvement in the disease process.   With appropriate manipulation of imaging sections, the  location and severity of sinus disease can be gauged. Mucosal  thickening is distinctly evident on CT scans, being more pro-  nounced in cases of sinusitis with polyps. Further diagnostic  information is available on the sinus content including air—  fluid levels. The patency of the sinus discharge tract can be  assessed with detailed view of the osteomeatal complex on  coronal sections thus allowing for surgical planning. The  presence or absence of nasal masses can be confirmed in CT  cases but can be used to differentiate between sinus polyps,  cysts or tumours. Generalised thickening or sclerosis of the  maxillary sinus walls may be indicative of chronic sinusitis  whereby early infective processes cause demineralisation of  the sinus wall and prolonged reactive host responses that  result in sclerotic bone deposition. Where sclerosis is more  localised in the maxillary sinus wall, there may be indication  towards enquiry of previous sinus surgery.   Cone beam computer tomography (CBCT) can provide  enhanced information on the pathological processes contrib-    Fig. 23.7 Diagram showing  the difference between the  fluid level and the mucosal    Differentiating sinus fluid and polyp on water’s radiographic view  ©Association of Oral and Maxillofacial Surgeons of India    Fig. 23.8 A coronal view of a CT scan showing thickened mucosal lining  of the both maxillary sinus with a fluid level on the left maxillary sinus    uting towards sinusitis, with slices as fine as 0.4 mm as well  as offering a lower radiation dose exposure, in the region of  10%, in comparison to a fine slice CT scan (Fig. 23.9).   This is more relevant for cases of maxillary sinusitis of  dental origin in which pathological processes can be tracked  from the tooth to the sinus structure.   MRI scans offer an imaging modality that allows some  enhanced interpretation in the appearance of the soft tissue  within the sinus. This is not relevant in the majority of  uncomplicated maxillary sinusitis presentations. The use of  MRI is limited to cases where there is opacification of the  maxillary sinus with no obvious obstruction, osseous abnor-  mality or odontogenic pathology. It allows the differentiation  between mucosal inflammation, complete fluid collection or  a tumour within the maxillary sinus as well as its origin.    Fig. 23.9 CBCT of the sinuses showing upper second molar with a  breach in the periodontal ligament space and periapical area opening into  the maxillary sinus causing sinusitis—a classic odontogenic sinusitis    In acute sinusitis cases, with a primary virus and secondary  bacterial infection, the aim of treatment focuses around  relieving of symptoms including pain, nasal congestion and  discharge during the 2-3 week period that it will take to  resolve. Antibiotics in the early stages are not recommended.  Advice can be offered in the management of systemic virus  infection including physical rest, adequate analgesia and  increased fluid intake.   The pain sensation from the maxillary sinus region is  attributed to pressure changes caused by occlusion of the    ostia and thus, treatment to promote unblocking will inher-  ently contribute towards pain reduction. During this process,  analgesia in the form of paracetamol and ibuprofen can be  utilised for management of pain.   Nasal saline and decongestants have been shown in some  literature to be an effective means of opening the ostia and  ecouraging ventilation.   Nasal saline mists and irrigations can offer a breakdown of  nasal blockages, dilution of irritants and allergens, reduction  of postnasal drainage and overall more effective mucociliary  clearance [29]. Lavage/irrigation of the nasal passage can be  performed using small quantities of salt or bicarbonate dis-  solved in warm water. These can be administered by inhaling  small volumes of the self-made formulation in cupped hands  through each nostril until nasal ventilation feels clearer.  Alternative over-the-counter devices such as squeeze-bottles  and syringes can be used. Humidified air and steam inhalation  can also be utilised as a means of nasal secretory blockage  breakdown. These irrigative techniques can offer supportive  relief to other symptomatic management methods but are not  deemed effective as monotherapy [30].   Where there is indication of chronic sinusitis, potential  risk factors should be identified and addressed, including  avoidance of triggers that may exacerbate allergies and asth-  matic flare-ups. Where applicable, patients should be encour-  aged to stop smoking or being exposed to passive smoke.    Where acute sinusitis symptoms last for longer than 10 days,  medical treatment modalities can be offered.   Topical nasal decongestants can be offered as a means of  improving sinonasal ventilation through reducing mucosal  secretion, nasal congestion and thus improved patency of the  osteomeatal complex. Topical formulations can include  phenylephrine (0.25%), oxymetazoline (0.5%) and xylo-  metazoline [31]. These should be limited to use twice a day  for up to 3 days. These formulations have a sympathomi-  metic effect causing vasoconstriction with subsequent  reduced fluid secretion and mucosal inflammation. Long-  term use of these agents can produce a rebound effect with  the absence of sustained vasoconstriction.   Topical intranasal glucocorticosteroids may be considered in  the management of prolonged acute rhinosinusitis or chronic  rhinosinusitis as an adjunctive or monotherapy prior to the  consideration of antibiotic prescription [32]. These can be  utilised for up to 3 months in adult patients depending on the  formulation used and especially where allergy is deemed a    significant risk factor. Common formulations utilised include  budesonide, ciclesonide, fluticasone furoate, fluticasone pro-  pionate, mometasone furoate and triamcinolone acetonide.  These have been deemed an effective means of clearing nasal  and sinus air passages in several studies when used in a ret-  roclined, head tilt action to encourage exposure towards the  middle meatus.   The use of systemic glucocorticosteroids has been reserved  for refractory cases of chronic rhinosinusitis, in particular  those with allergy [2], as well as initial treatment for patients  with suspected allergic fungal rhinosinusitis. It can provide  symptomatic relief through improving ventilation through  the sinuses, reducing the size of polyps and thus restoring  some sense of smell. Current British guidelines suggest  prednisolone 0.5 mgk/kg for 5—10 days as well as the adjunct  therapy with betamethasone nasal drops [33], taking relevant  consideration of those already on steroids for other  conditions.   There is limited evidence to support the use of antibiotics in  the short term for acute rhinosinusitis. A Cochrane review of  10 trials based in the primary care environment found that  irrespective of treatment modality with or without antibiot-  ics, 71% of patients’ symptoms of uncomplicated acute  sinusitis had resolved by the 2-week mark [34]. Where  symptoms of sinusitis arise, the microbes of dominance usu-  ally include aerobic streptococcus pneumonia, haemophilus  influenza and Moraxella catarrhalis. Antibiotic therapy  should be reserved for cases of acute exacerbations of rhino-  sinusitis where symptoms haven’t resolved after 7-10 days  or for severe cases involving signs of systemic spread includ-  ing fever and severe unilateral facial pain. Though the evi-  dence is limited, some literature supports the use of  amoxicillin for 7-14 days. This is mostly effective; however,  approximately 20-30% of haemophilus influenza strains  have been found to be resistant to amoxicillin due to the pro-  duction of lactamase [35]. During persistent periods of acute  sinusitis or during exacerbations of chronic sinusitis, there is  a shift towards a mixture of anaerobic and aerobic pathogen-  esis. The Infectious Diseases Society of America recom-  mends amoxicillin clavulanate as the first choice of antibiotic  for 5—7 days [36], with clindamycin, doxycycline, levofloxa-  cin or moxifloxacin for those with an allergy to penicillin.  This can be used in combination with topical glucocortico-  steroids to attain more efficient symptom relief [32]. In cases  of chronic sinusitis, use of low-dose macrolides has shown  some effectiveness [14]. In all cases, where viable, the choice  of antibiotic should be guided by microbiological culture  growth, attained from discharges from the middle meatus or  surgically guided sample collection.    Surgical intervention is routinely carried out by Ear, Nose  and Throat speciality and is usually indicated in the failed  medical management of chronic sinusitis or as the first treat-  ment for acute fungal rhinosinusitis. The aim of surgery is to  attain normal function through restoration of ventilation and  allowing physiological mucociliary drainage of the sinuses.  This can be through opening and widening of the osteome-  atal complex, removing foreign body and polypoid tissue,  clearing the sinus of infected mucin, removal of chronically  inflamed mucosal and bony tissue whilst throughout preserv-  ing as much of the virgin, healthy mucous membrane in the  sinus as possible.   Extra-oral or intra-oral approaches can be taken. The  classically used internal access is the Caldwell-Luc  approach. George W Caldwell first published this technique  in the New York Medical Journal in 1893, where he utilised  the canine fossa approach to gain access to the sinus and  perform intranasal drainage, significantly improving surgi-  cal outcomes. Henry Luc, a french surgeon, further adapted  this method in 1897 for surgical treatment of chronic sinus-  itis where performed antrstomy in the middle meatus whilst  Caldwell had performed an inferior meatal antrostomy.  23.9.3.1 Surgical Method: Caldwell-Luc  Approach  Advanced imaging like CT or CBCT should be used for the  procedure. Particular awareness is required for the presences  of any septae that may interfere with the Caldwell-Luc  access in to the sinus. In addition, assessment is required of  the availability of a window on the anterior wall of maxillary  sinus, with short maxillary sinus height creating challenges  in this approach.   This procedure can be done either under a general or a  local anaesthetic with sedation support; though complete  painrelief and anaesthesia with the latter option is difficult  to achieve (Fig. 23.10). Once adequate anaesthesia has  been achieved, the upper lip is retracted an incision is made  2-3 mm above the mucogingival junction, parallel to the  occlusal surface of the teeth. A full-thickness mucoperios-  teal flap can be raised with a molt’’s periosteal elevator to  reveal the underlying bone. Often, bulbosities caused by  the root projections of the upper canines and premolars are  noticeable and they can be used as anatomical landmarks to  avoid damaging the roots of the teeth. The periosteum can  be raised elevated all the way to infraorbital foramen and  care must be taken not to stretch the infraorbital nerve.  Then a bony window can be made with a Rosehead bur  2-3 mm above the root apices of the teeth. On entry in to  the sinus, a microbiology swabbing of the sinus content is  done for culture and sensitivity. Once the swab has been  taken, this is followed by stripping of the sinus lining, espe-    Fig. 23.10 A diagram showing the intraoral approach for the Caldwell-  Luc technique    cially when treating chronic, persistant sinusitis. The lining  can be removed with a microdebrider, Freer’s elevator and  curettes. Care must be taken not to remove tissue from the  roof of the sinus due to the fact infraorbital nerve can be  seen through the canal resorbed by maxillary sinusitis.   Any soft tissue curetted from the sinus can be sent for  histopathological examination. A 30 or 45 degree endo-  scope is used to visualise the floor of the sinus which is not  feasible with a standard 0 degree FESS. To complete the  procedure, an intranasal antrostomy can be done to improve  the drainage of the sinus. This procedure can be done by  passing a curved haemostat through the nasal aperture to  penetrate the lateral nasal wall, 1-1.5cm posterior to the  anterior attachment of the inferior nasal turbinate. Care  should be taken to avoid injuring the opening of nasolacri-  mal duct. The projection of the haemostat can be visualised  with an endoscope in the sinus simultaneously. Forceps are  used to remove the fragments of bone created from the  enlargement of the ostium and thus complete the intranasal  antrostomy. The intra-oral Caldwell-Luc access is used to  provide a final saline-wash within the sinus, prior to achiev-  ing haemostasis and would closure, often with resorbable  sutures.    23.9.3.2 Complications with Caldwell-Luc  approach  Complications associated with this surgical technique  include infraorbital nerve parasthesia that is often transient  and may last up to 6 months. Similarly there may be numbess  of the attached gingivae and associated teeth or even possible  devitalisation. If the lacrimal apparatus has been encoun-  tered, there may also be the risk of dacryocystitis.    Fig. 23.11 (a and b) Naso endoscopic pictures showing as the scope enters the left nostril. Nasal septum (NS) on the left and Inferior turbinate  (IT) on the right and the uncinate process (UP). Further up showing maxillary sinus ostium (SO) and Uncinate process (UP)   With technology continually advancing, many prospective  studies report functional endoscopic sinus surgery (FESS)  (Fig. 23.11) to be a safe and effective means of managing  chronic sinusitis. For the FESS approach to be an effective  surgical method in the management of chronic sinusitis,  appropriate patient and surgical instrumentation related fac-  tors require consideration. Standard preparation for FESS  involves an oral endotracheal tube which can be positioned  based on surgeon’s convenience to improve the access. Prior  to donning surgical scrubs, the neuro-patties soaked in a  vasoconstrictor solution may be placed along the floor and  middle portion of the nasal cavity such that it is effective at  the start of the operation. In addition, all Encoscopic acumen  should be ready for the beginning of the procedure.  Endoscopic instrumentation includes a 0, 30, and 70 degree  angle scope, a powered debrider with a 4 mm straight and a  60 degree cannula, 4 mm long curved suction, various types  of punch forceps, curettes and a monopolar suction cautery.   Before the start of the procedure, neuro-patties are  removed and 1% lidocaine and 1:100000 adrenaline injected  into the septum, middle turbinate and uncinate process for  the maxillary sinus-related issues. To survey the width and  depth of the nasal cavity and also to establish the boundaries  to avoid any complications, a systematic examination of the  nasal cavity carried out with a 30 degree scope attached to an  endoscopic tower/viewing screen. All the nasal structures    should be visualised including posterior nasal choana and  the inferior turbinates.   Systematic intranasal survey with the scope is also carried  out as a part of the surgical planning to identify any nasal sep-  tal spur, septal deviations and turbinate hypertrophy to improve  the access and to prevent any complications. Additionally, any  polyps can be removed to improve the access. An angled probe  is used to reflect the uncinate process to visualise hiatus semi-  lunaris and infundibulum. Back fracturing the uncinate pro-  cess finally allows visualisation of the maxillary sinus ostium  and medial wall of the orbit. A 4 mm trimmer can be used to  remove uncinate and part of the middle turbinate to gain access  to maxillary sinus ostium. The superior border of the sinus  ostium is an important anatomical landmark as it is the junc-  tion of the medial wall of the orbit and the lamina papyracea.  At this point of dissection, a decision can be taken to do a  minimal or extensive dissection process, and this depends on  the extent of the disease process. Mostly, a minimal dissection  (expansion of the ostium) is all that is necessary.   FESS is an essentially safe procedure in the hands of a  trained and experienced surgeon; however there are a wide  range of risks associated with this procedure due to the prox-  imity of anatomical structures such as the orbits and their  content, major arterial and venous structures and the base of  the skull. Severe complications can include orbital content  penetration that may lead to fat herniation, enopthalmous    and damage to extraocular muscles; penetration in to the  skull base can result in cerebrospinal fluid leakage and  carotid artery dissection may cause a stroke or even death.  Orbital content penetration leading to fat herniation, enoph-  thalmos and damage to extraocular muscles. Crusting, septal  perforation, mild bleeding, nasal obstruction, anosmia, mini-  mal fat herniation from orbital wall perforation and crusting  of the nasal mucosa are examples of what are believed to be  minor complications.   Sinus surgery should be supported with medical manage-  ment post-operatively to prevent further inflammation devel-  oping, particularly in the case of polyp removals that may  re-establish without maintenance therapy.    Sinusitis can be a debilitating condition for patients whether  acute or chronic. With close proximity to the dentition,  symptoms of dental pain can result in presentation to the  maxillofacial and dental professional. A succinct clinical his-  tory and examination is vital in attaining an accurate diagno-  sis. Though management is guided by diagnosis, management  should commence with symptom relief.    Acknowledgements We would like to acknowledge Mr. Martyn  Barnes and SurgTec for the endoscopic pictures attached to this chapter.  More endoscopic images and videos can be accessed from www.surg-  tech.net website.    1. Lawson W, Patel ZM, Lin FY. The development and pathologic  processes that influence maxillary sinus pneumatization. Anat  Rec: Advances in Integrative Anatomy and Evolutionary Biology:  Advances in Integrative Anatomy and Evolutionary Biology. 2008  Nov;291(11):1554-63.   3. Pommer B, Ulm C, Lorenzoni M, Palmer R, Watzek G, Zechner  W. Prevalence, location and morphology of maxillary sinus septa:  systematic review and meta-analysis. 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Open Access _ This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.  org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropri-  ate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.    The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in    a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.    Routine exodontia is a common procedure performed by the  general dental practitioner and the oral surgeon alike. Most of  the maxillary premolar/molar extractions heal uneventfully  but some may cause inadvertent opening into the maxillary  sinus, manifesting as immediate oro antral communications  (OAC) or delayed oro antral fistulae. The common reasons  being difficulty encountered in the extractions intra opera-  tively due to myriad reasons or the OAC may be due to a pre  existing pathology in the peri apical region or within the sinus  lining. Whatever the reason be , its paramount that the sur-  geon identifies the problem and approach it in a_ sequential  manner to avoid long term consequences and to attain a per-  fect closure. The timing of the closure is crucial which is  dependent upon the sinus health and the socket condition.  This may be complicated by a missing root tip which is lying  in the sinus. This chapter aims to walk the reader through  these events in a logical fashion, so that they can take appro-  priate decisions and use the correct surgical technique which  will ensure a successful closure of the defect.    24.1 Introduction  Maxillary sinus is an anatomical area, which is intimately  associated with the field of oral and maxillofacial surgery.  Many of the procedures done violate the integrity of the  maxillary sinus, as in orthognathic surgeries, or when the  sinus is involved per se as part of midface trauma or in odon-  togenic pathologies that infringe upon the sinus.   The relevance of the sinus in day-to-day minor dentoal-  veolar surgical procedures is that the sinus floor is in very    Electronic Supplementary Material The online version of this chap-  ter (https://doi.org/10.1007/978-98 1-15-1346-6_24) contains supple-  mentary material, which is available to authorized users.    S. Manuel   Department of Oral and Maxillofacial Surgery, Ananthapuri  Hospitals and Research Institute, Trivandrum, Kerala, India    © The Association of Oral and Maxillofacial Surgeons of India 2021    close approximation with the roots of the maxillary posterior  teeth, especially the molars [1].   Eberhardt, in 1992, did a CT study to evaluate the dis-  tance between maxillary sinus floor and the apices of the  maxillary pre-molar/molar teeth. The buccal first premolar  showed the largest value of 6.18 mm (SD 1.60 mm). It is  quite disturbing to know that the mesiobuccal root of maxil-  lary second molar is only 0.83 mm (SD 0.49 mm) away from  the maxillary sinus floor, as per this study results. Readers  are advised to refer the table in reference [1] to have a better  picture of this relevant CT study.   This intimate relation with the root of maxillary molars  causes many a time inadvertent communication between the  sinus and oral cavity causing acute OroAntral communica-  tion (OAC). If the OAC is unrecognized or not dealt with  primarily, either it may undergo spontaneous healing if the  circumstances are favourable or it may progress into a full-  fledged OroAntral fistula (OAF), which will need secondary  intervention for closure.   This section of the book deals with OAC and OAF caused  during exodontia and minor dentoalveolar surgical proce-  dures, cyst enucleation and small-sized tumour excision.   Communications caused due to excision of moderate to  large pathologies, post-oncosurgery defects, major maxillo-  facial trauma, gunshot/missile injuries, osteoradionecrosis  and developmental and congenital deformities usually may  require locoregional/free flap transfers and/or prosthetic  rehabilitations. Such communications are dealt with else-  where in this book.   This section is limited to closure of OAF caused after  exodontia; however, many surgical techniques used for OAF  closure do overlap with surgical closure techniques of orona-  sal and palatal fistulas. Those techniques are dealt with in  relevant sections of the book.   This chapter also deals with managing and retrieving  root/root tips, which are inadvertently displaced into the  sinus (Root in sinus).   Most of the surgical procedures aimed at correction of  OAC/OAF are doomed to fail if the underlying sinus is not    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1-15-1346-6_24    healthy before the anticipated closure. The “Antral regime  procedures” are aimed at ensuring a disease-free sinus before  anticipated elective closure of a post-extraction OAF, When  patients are referred to oral surgeons for treatment of OAF,  depending upon the duration of complaint, the sinus may be in  various stages of the disease. It is difficult to ascertain whether  the sinus was diseased primarily at the time of exodontia,  accentuating the chance of an OAF formation or whether the  sinus had been secondarily infected following the formation of  OAF due to direct communication with the oral cavity. Another  possibility is that the sinus lining would have been secondarily  involved by a periapical pathology and removal of the involved  tooth was conducive to the formation of the OAC.   The role of an otorhinolaryngologist cannot be under-  stated, and at times, the closure has to be attempted after con-  sulting with them regarding the sinus health. Their presence  may be required during the closure for allied procedures in  the sinus like FESS (Functional Endoscopic Sinus Surgery).    1. Aberrant anatomy causing the sinus floor to dip down  between the roots of premolars and molars/decreased  thickness of sinus floor.   2. Unusually long roots, which lie in close proximity to the  sinus floor/Schneiderian membrane.   4. Removal of root canal-treated maxillary molars is usu-  ally difficult due to the brittle nature of the tooth.   Attempted removal of brittle root tip fractures in such  teeth shows an increased chance of getting OAC.   5. Improper use of dental elevators when attempting to  remove root tip can cause undue vertical forces, which-  may push the roots into the sinus (Fig. 24.1).   6. Progressive pneumatization of the sinus as age advances,  especially around lone standing molars (Fig. 24.2).   7. Progressive pneumatization is also a cause for OAC dur-  ing removal of maxillary third molars especially when  associated with tuberosity fractures.   8. Teeth, which have periapical pathologies, cause bone  loss/erosion at the sinus floor and are at a higher chance of  causing OAC after extractions. It is imperative that such  cases are identified pre-operatively, adequate radiographic  examinations are done, the patients are pre-warned and  necessary measures are to be taken to close the OAC, if  they occur during the procedure (Fig. 24.3a, b and c).   9. Occasionally, odontogenic infections/abscess may  spread to the sinus, which may manifest “Fluid levels”  in the sinus on paranasal sinus X-rays. Extraction of  such teeth involves a greater chance of having OAC.    Fig. 24.1 Improper use of dental elevators causing pushing of root tip  into maxillary sinus    Fig. 24.2 Sinus dipping down in a long-standing edentulous area of  upper left first molar (IOPA)    10. Lack of adherence to basic principles of dentoalveolar  surgery or overzealous/aggressive attempts to remove or  retrieve fractured root tips of maxillary posterior teeth  may cause OAC. It is the judgement of the concerned  clinician whether to attempt removal of a fractured root  tip; if the clinician can remove the root tip via the socket  through closed intra-alveolar technique well and good,  if not the clinician should be able to remove the tip via  transalveolar technique based on sound dentoalveolar  surgical principles and should be able to close the OAC  if it occurs. If the clinician feels that he is not able to  perform the above-mentioned procedure, it may be wise    Fig. 24.3 (a) IOPA ofa  molar showing periapical  lesion, (b) Extracted molar  with the lesion attached to the  root tip, (c) Diagrammatic  representation of periapical  lesion close to sinus floor    not to vigorously attempt to remove the root tip. Either  he should get expert help or it would be judicious to  leave the root tip behind and attempt removal later if  required when expert help is available (Fig. 24.4).   11. Teeth, which have aberrant root anatomies, dilacera-  tions, hypercementosis and ankylosis, are all at risk of  developing OAC.    The basic rule to be followed when we suspect an OAC is  never to enlarge or aggravate the existing communication.  Most of the time OAC goes unrecognized, and it may heal  spontaneously if it is less than 3-5 mm in diameter [2]. If  a bigger OAC is not recognized and adequate measures  are not taken for closure, it may progress to OAF. Unless    it is an evident OAC, confirmatory tests are not done in  order to prevent enlarging the OAC. Literature also says  that sinusitis will ensue if the OAC is not closed within  24-48 h.    1. Bubbling of mucous or blood may be seen at the socket  opening when the patient exerts pressure via a closed nos-  tril (Valsalva manoeuvre).   4. Close examination of the socket apex under direct light  vision may show the sinus lining or opening into the  sinus.   5. There may be changes in the resonance of the voice.   6. An OAC should be suspected if a piece of antral floor is  attached to the root end after extraction (Fig. 24.5).    Fig. 24.4 Diagram showing the importance of slow, careful and fine  movements to remove root tips with straight probes, fine mosquito for-  ceps or apical fragment ejectors    There may not be radiological evidence of a small OAC ona  routine IOPA, unless there is sizeable loss of antral floor or  breach in antral floor, which will manifest as a direct com-  munication between the sinus and socket. It is not advisable  to insert a probe or radiopaque marker into the socket and  take an x-ray as it may enlarge the OAC.    24.3.2 Management of OAC  The OAC may be managed in the following step wise approach:    1. If you suspect an OAC, it is prudent to inform the patient  about the anticipated treatment plan and the sequel.    Fig. 24.5 Note the sinus floor attached to the roots of an upper third  molar after extraction, with associated tuberosity fracture. It is a defi-  nite case of OAC, which warrants primary closure if conditions are  favourable    Patient has to be aware of the condition as post-  operative compliance form of the patient is of paramount  importance in order to prevent any dehiscence or clot  break down at the OAC closure site. (See antral regime  section. )   2. Openings less than 3-5 mm in size may be left without  any intervention hoping for spontaneous healing, or a  primary closure may be attempted depending upon  individual case scenarios. If left for spontaneous heal-  ing, patients are specifically instructed to avoid any  manoeuvres, which may increase the intra-sinus  pressure.    A routine suturing across the socket in maxillary premo-  lar/molar extraction sites may not suffice in suspected cases  of OAC, as the buccal and palatal gingivae may not approxi-  mate primarily and healing may be secondary in nature.  Suturing in such cases just plays a role in supporting the clot.  If aiming at primary closure to treat OAC, the buccal and  palatal gingivae may be approximated by the following addi-  tional measures:    (a) Reduce the height of the buccal/palatal alveolar bone in  order for the sutures to approximate.   (b) As it is the palatal mucoperiosteum that is more adher-  ent, a semilunar relaxing incision may be placed about  5 mm away from the palatal gingival edge and the flap is  advanced buccally to meet the buccal gingivae  (Fig. 24.6).    Fig. 24.6 Depicts releasing incision in the palate, to advance the flap  in order to achieve primary closure of the socket    Beyond these two steps, any attempt at closing the OAC  would mean that the surgeon is using techniques that are  common with established techniques of closing an OAF. If  primary closure is not obtained by (a) or (b), the next logical  step would be to raise a buccal full thickness three-sided  (trapezoidal/rectangular/4 cornered) flap and advancing it to  the palatal side. At this stage, if adequate relaxation is not  present for the flap, the mucoperiosteum may have to be  scored and the details of this are given in OAF surgical clo-  sure section of this chapter.   If the sinus is healthy, the best chance of closing an OAC  is at the time of occurrence and the surgeon may use any of  the techniques in his armamentarium, and these decisions are  taken on a case-by-case basis.    A simple clinical scenario is given here as food for  thought for the young readers (Fig. 24.7).   I believe that there may be different opinions, with  few possible ones being    1. Extract the tooth and allow the lesion to regress/  observe periodically.   3. Extract the tooth via transalveolar technique and  enucleate the lesion.   6. Be aware of the possibility of an OAC after extrac-  tion and be prepared for the possible technique of  closure.    This case was included just to show how perplexing  a routine clinical situation could be and to stress on the  importance of a solid pre-operative plan before  attempting such cases.    Intrusion into the maxillary sinus and establishment of direct  communication with the oral cavity are referred to as an oro-  antral fistula (Fig. 24.8a and b). An oroantral fistula is a path-  ological condition in which the oral and antral cavities have  a permanent communication by means of a fibrous connec-  tive tissue fistula coated by epithelium. Once an unrecog-  nized OAC does not heal or there is failure of attempted  closure, the condition progresses to an OAF, which means  that the epithelization of the communicating tract has  occurred. Usually, such cases get referred to the oral surgeon  from the general dental practice within 2—3 weeks of the  occurrence, when patient notices oronasal regurgitation.    The causes for OAF are similar to those of OAC mentioned  earlier. Apart from this, if the sinus has pre-existing sinus-  itis/antral pathology/fungal infections/fungal balls, the    Fig. 24.7 This is the OPG of  a 25-year-old man who  reported for routine extraction  of root stump of upper left  first molar tooth. OPG shows  an incidental finding of a  periapical lesion (which is  probably a periapical cyst that  appears to be very close to the  sinus floor or probably  pushing the sinus lining up).  How would you manage this  case?    Fig. 24.8 (a) Note the OAF on upper left first molar extraction site. The socket edges are well-healed, epithelized and rounded off. (b) OPG of  the above case showing a defect in the alveolar ridge in the 26 socket region and direct communication of the sinus with the oral cavity    chance of healing of OAC is decreased and may progress  to OAF.   Among patients who do not follow the post-extraction  instructions or where the clot is deficient/gets dislodged,  chances of OAF are increased in susceptible cases. Failed  sinus lift procedures, ailing and failing implants and peri-  implantitis are all potential causes for causing OAF.    1. Primary complaints in established OAF cases are mainly  oronasal regurgitation and burning sensation in sinus on  having food.   2. Patients may visit the ENT surgeon with complaints of  acute sinusitis, secondary to infection of sinus via unrec-  ognized OAF.   3. In certain cases, there may localized pain, tenderness,  foul smell, unpleasant tasting discharge, persistent nasal  discharge and post-nasal drip.    and radiological features of chronic sinusitis. The antral  lining will undergo thickening/hyperplasia, and eventu-  ally, sinus gets obliterated or there may be evidence of  sinus polyps.   I have seen a case where the patient was referred with  a protruding sinus polyp through the socket of an untreated  OAF in a maxillary molar site (Fig. 24.9a and b). In this  particular case, a root was displaced into the sinus as well.  It was not sure whether this polyp ensued secondary to  OAF or whether pre-existing sinus polyp leads tothe  OAF.   We should also be aware that antral malignancies  may protrude through the unhealed socket of maxillary  molars. Most of the times, the surgeon being ignorant  of the disease would have extracted the tooth due to  mobility caused by the erosion due to the malignant  lesion, and a few weeks after, the patient may present,  with the lesion protruding through the socket  (Fig. 24.10).    Fig. 24.9 (a) Clinical picture showing an antral polyp protruding through the sinus. Some clinicians may consider this to be a Post-extraction  granuloma possibly of a reactive nature due to the root in the sinus. (b) Occlusal X-ray view showing root in the sinus    6. Incertain cases, the ridge will clinically look well-healed;  ©Association of Oral and Maxillofacial Surgeons of India however on careful probing, an unhealed tract will be  seen, leading to the sinus (Fig. 24.11).    Fig. 24.10 A case of extraction of upper right second molar due to  mobility by dental surgeon, who was unaware of the cause of mobility   5. The mucosal edges of the socket will be rounded off, and mouth closed may elicit oronasal regurgitation.  an evident opening may be seen via the socket into the 2. Hold a piece of cotton wisp with tweezers at the OAF  sinus. opening site, and request the patient to blow through the    nose with the nostril closed. The wisp will vibrate under  the flow of air via the OAF (cotton wisp test/butterfly test).   3. The patient may find it difficult to hold pressure within  the sinus, and a whistling sound may be appreciated by  the examiner during the Valsalva manoeuvre.   4. Holding a mouth mirror near the opening of OAF will  cause fogging of the mirror.   5. Place the nozzle of the suction at the opening of the fistu-  lae. A sound similar to blowing through the mouth of an  empty bottle may be heard.    Techniques for OAF closure have evolved over a long period  of time and have a robust history. Many techniques have  been time tested and well-established, form the mainstay of  OAF closure and will be discussed in this section. Literature  is replete with various technical modifications; it is not pos-  sible to discuss all these in detail and will be beyond the  purview of this chapter. The reader is advised to look into the  references if a thorough review of techniques is required [3,  4]. Figure 24.1, in reference [4] (Visscher et al. JOMS 2010),  gives an excellent overview of the various treatment modali-  ties for oroantral communications Awang et al. [5] back in  1988 have published an excellent review of techniques,  which were established at that time.   Since a plethora of techniques are available, the surgeon  has the freedom to choose the technique, which works well  in his hands based on the training received and surgical com-  petence. One cardinal rule, which may be followed in OAF  closure, is to start with the simplest technique available and  reserve the complex technique in case the first attempt fails.  A sequential option may be followed, the patient is to be  warned that there are chances of failure and a secondary or  tertiary surgery with more complex techniques may be  required at times.   At this stage, it is worth remembering a quote which I  have come across somewhere: “Re-operation after past fail-  ures at the hands of other surgeons should be approached  with due humility”.   The options for treatment can be broadly categorized  under the following headings:   ¢ Combined with autografts.  ¢ Combined with allografts.  ¢ Prosthetic options.   2. Buccal advancement flap with buccal fat pad grafting  (Two-layer closure).    3. Palatal pedicled flap (Ashley’s rotational flap).  4. Tongue flaps: anterior and posterior based.    The multitude of techniques and variations has made the  literature on OAF closure a trifle confusing. It is interesting  to know that even third molar auto transplantation has been  found to be successful in closure of immediate OAC  (Kitagawa 2003) [6].   In this chapter, we will only be discussing the time tested  and commonly performed buccal/palatal flaps with a reason-  able amount of success rate. The tongue flaps are a second  option, but the difficulty is caused to the patient in the post-  operative period until the pedicle is divided and the need for  patient compliance, difficulties in feeding, mastication;  speech and maintenance of oral hygiene should be taken into  consideration before performing them.   As there are multitude of variations and modifications in  OAF closure techniques, the author feels that it is wise to pres-  ent all the relevant modifications in a sequential order (Box  24.1). If the reader refers to the historical evolution of tech-  niques given in the box format, it is evident that different flap  designs have been advised ranging from advancement, sliding,  pedicled, rotation, bridge, hinged, transverse buccal, double  flaps, island flaps, bipedicled flaps, submucosal connective tis-  sue flap, osteoperiosteal flaps, buccinator myomucosal flaps,  etc. Each technique has been presented with its own indica-  tions and advantages. The reader is advised to read individual  publications to get details of these techniques if required.   Irrespective of the technique used, the success of the clo-  sure warrants that the basic sound principles of mucoperios-  teal flap design are used. The flap should have adequate  blood supply, should be handled gently, and should lie in the  advanced position without tension.    The following factors should be assessed while planning the  technique of closure in an OAF.   Size of the communication (Bone defect is always bigger  than the visualized soft tissue defect)    When treating an OAF, the surgeon should have the follow-  ing objectives in mind [7]. (This can be called the 4 E’s).    1. Elimination of the antral pathology.  2. Elimination of the epithelial lining of the fistulous tract.    3. Establishment of stable closure of fistula.  4. Establishment of satisfactory drainage.   e Kruger GO 1984: V-shaped excision of lesser cur-  vature of palatal rotation flap [13].   e Egeydi 1977: Buccal fat pad and split thickness  graft [26].   e Brusati 1982: osteoperiosteal flap + vestibule muco-  periosteal flap [30].   e Carstens MH 1991: anteriorly based buccinator  myomucosal island flap [33].   e Pandolfi 2000: Three layer closure of oroantral  cutaneous defect—palatal flap + buccal fat pad +  skin flap [39].    e Lee JJ 2002. Repair of OAC in the third molar  region by random palatal flap [40].   e Sandhya 2016: Resorbable GTR Membrane and  FDMB Sandwich Technique [45].    The names of Moczair, Berger and von Rehrman have been  used interchangeably when speaking of buccal flaps in the  literature. The buccal flap designed by Moczair [9] was a  sliding trapezoidal flap, while the ones designed by Berger  [11] and Von Rehrman [10] were buccal straight advance-  ment mucoperiosteal flaps.   Von Wowern (1982) [47] in a study of 90 patients com-  pared Moczair with Rehrman flaps and advocated the former  for treating OAF in edentulous patients. Killey and Kay (1967)  [48] proved the efficacy of buccal flap in a large series of 250  cases. The buccal flap technique can be satisfactorily employed  in the treatment of small and medium-sized communications  where there is clear sinus lavage through OAF, and proper  antral regime has been maintained 4—5 days prior to the  surgery.   The technique of raising a buccal flap is given along  with the 2 layer BFP closure technical note box (Box 24.2)  and is essentially the same. A few words are needed to  elaborate on the buccal flap and periosteal scoring. The  buccal flap raised is a full thickness trapezoidal (rectangu-  lar/4 sided) mucoperiosteal flap. There are 2 releasing  incisions, one anterior and one posterior. The incisions are  put in such a way that the flap looks tongue/funnel-shaped  and is feasible for advancement palatally without tension.  Great care is given to raise it gently without causing any  ‘button holing’/fenestrations in the flap. The base should  be broad enough to have good random blood supply, and  flap margins should be incised sharply in order to avoid  ragged edges. It is the periosteum that gives tension and  may prevent advancement palatally. In order for the flap to  lie passively, the periosteum alone is scored gently with a  number 12 or 15 blade, horizontally at the level of the base  of the buccal flap. This will release the tension and help in  advancement. The scoring is a fine procedure, and the sur-  geon should be aware that, if the scoring goes deep beyond  the level of periosteum, the mucosa may be incised which  may even jeopardize the viability of the flap by affecting  the blood supply emanating from the base (Fig. 24.12).   e Palatal margin made into a semilunar shape to  accept the buccal flap.   e Flap to rest on sound bone on the palatal side.   ¢ Buccal flap sutured to palatal margin with horizon-  tal mattress vicryl sutures.    One disadvantage of all buccal advancement procedures  is the decrease in the vestibular depth, which may be prob-  lematic for prosthetic rehabilitation.    24.5.1 Step-by-Step Technique of Doing  Buccal Advancement Flap + Buccal Fat  Pad Grafting (BFP)    The step-by-step procedure for 2 layer closure technique is  given in the box format (Box 24.2). The steps of performing  a 2 layer closure are similar to the buccal advancement alone,  except that the BFP is raised, advanced and sutured primarily  to the palatal edge.   The use of the buccal fat pad (BFP) as a grafting source in the  closure of intra-oral defects has gained popularity in the last  quarter of the twentieth century. Its use as a pedicle graft for oral  reconstruction was first reported by Egyedi in 1977 [26]. Studies  have proved through a series of cases that the use of buccal pad  fat in the closure of oroantral communications has significantly  reduced the failure rate of the treatment. The closure of OAF  with single-layered buccal mucoperiosteal advancement flaps  (Berger/Reherman) has been well documented in the literature.  Without much change in the surgical steps, adding a second  layer of BFP will enhance the success rate of closure.   The buccal fat pad (BFP) as an anatomic element was first  mentioned by Heister in 1732 and was described by Bichat in  1802 [49]. The BFP (Bichat ball) is an anatomically rounded  and biconvex structure that is of great importance in the facial  contour. It is an adipose tissue surrounded by a thin capsule    and located inside both masticatory spaces in the oro-maxil-  lofacial region (Fig. 24.13). The BFP has a central body with  four extensions: pterygopalatine, temporal, pterygoid and  buccal. The central body and buccal extension account for  approximately 50% of the BFP and are the most clinically  significant portions. The BFP has a 10 mL volume, a thick-  ness of 6 mm and an approximate weight of 9.3 g. The BFP is  surrounded by a thin fibrous capsule. Blood supply is pro-  vided by the vestibular and deep branches of the maxillary  artery, the transverse facial branches of the superficial tempo-  ral artery and branches of the facial artery. The rich blood  supply may explain the high success rate. It also may be one  reason for the quick epithelialization of the fat. The buccal fat  pad is a mass of specialized fatty tissue called as syssarcosis,  a fat that enhances muscular motion. It is distinct from the  subcutaneous fat and shows marked similarity to the orbital  fat. It can easily cover small to medium sized defects of about  4 cm in diameter. When properly dissected and mobilized, the  BFP provides 7 x 4 x 3 cm of a pedicled graft. (Box 24.3).    24.5.2 Clinical Pictures Demonstrating 2 Layer  Closure Technique with BFP (Fig. 24.14a,  b, c, d and e) [50]    Figure 24.14a, b, c, d and e: Reprinted with permission from  springer nature customer service centre GmbH: springer  publisher: Journal of maxillofacial and oral surgery: The ver-  satility in the use of Buccal Fat Pad in the closure of oro-  antral fistulas. Suvy Manuel et al. [COPYRIGHT  4524640093264] (2015).   ¢ Low rate of complication.  ¢ No donor site morbidity.  ¢ Low risk of infection.    Among palatal flaps, there are 2 main types: The palatal  straight advancement flap (Fig. 24.15) and the palatal rota-  tional flap (Fig. 24.16).   However, the palatal rotational flap proposed by Ashley in  1939 [12] has stood the test of time. It is a pedicled flap,  posteriorly based on the greater palatine vessel. A tongue-  shaped full thickness mucoperiosteal flap is raised on the  side of the OAF. The OAF site is freshened, and the fistula is  excised as a preparation to receiving the flap. The flap is  rotated and sutured on to the OAF site. In order to avoid  kinking at the site of rotation near the palatal margin of the  socket, a V-shaped area may be excised (Kruger’s [13] modi-  fication). The raw site is packed with dressing to allow sec-  ondary healing. This is a thick, bulky and vascular flap,  which is quite reliable and serves often as a second line of  defence when the buccal advancement flap fails. Different  authors have given various names for this flap-like rotational,  advancement and transposition.   Other types of palatal flaps mentioned or published in the  literature are the palatal island flaps (Henderson 1974 [21]),  palatal hinged/inverted/reverse flap (Rintala 1971 [18]) and  sub-mucous connective tissue flap (Ito & Hara 1980 [28]).  Palatal flaps are also used as part of double flap techniques as  proposed by Zeimba in 1972 [19] and Quayle in 1981 [29].    The health and status of the socket edges and margins play  an important role in deciding the success of the closure, irre-  spective of the surgical technique used. An OAF, which is  well-rounded margins and does not show any evidence of  oedema/inflammation, is a good recipient area for the clo-  sure. Oral surgeons may often get referred cases with history  of difficult extraction of maxillary molars/attempted removal  of fractures root tips/cases with established OAC and/or with  missing root tips. Often, the socket may show evidence of  traumatic extraction with ragged margins, tissue loss, irregu-  lar bony edges, congestion, tenderness and oedema. Such  sites are not favoured for an OAC/OAF closure, and surgeons  should not be tempted to attempt a closure. The chances of  failure of the closure are high due to unhealthy mucosal con-  dition and its prudent to wait for a couple of weeks for good  healing of the wound edges and then consider closure. It may  be argued that the sinus health may deteriorate during this  waiting period, and all these are decisions to be taken by the  surgeon on their individual merit (Fig. 24.17a and b).   Depending upon the duration of OAF, the sinus may be in pus collection in sinus or antral polyps. In cases of acute   various stages of disease. In acute OAC, unless there is pre- nature, the sinusitis has to be under control before closure  existing disease, the closure may be attempted with a fair (Fig. 24.18).    Fig. 24.14 (a) Oroantral fistula seen at the maxillary right first molar | margin. (d) The buccal mucoperiosteal flap sutured to the palatal mar-  extraction site (b) Buccal fat pad being teased out from the buccal ves- _ gin and covering the buccal fat pad. (e) Excellent healing of the closure  tibule. (c) The buccal fat pad being advanced and sutured to the palatal _ site (2 month post-operative view) [50]    Fig. 24.17 (a) Clinical picture of a referred case in a 30-year-old male,  who had a traumatic extraction of upper right first molar 1 week back.  One complete root has been pushed into the sinus (see OPG,  Fig. 24.17b). Note the traumatized, congested, oedematous and ragged    Fig. 24.18 A coronal CT scan, showing periapical widening/lesion in  a maxillary left molar, which is close to the sinus floor and reactive  sinus lining thickening in that region. Possible OAC resulting from this  extraction may have a decreased chance of success after immediate  closure    Antral regime is usually helpful, which is usually started  about 5-7 days before the anticipated closure. It includes.    1. Antibiotics to control sinusitis.  2. Anti-inflammatory agents if required.  3. Steam inhalation at prescribed intervals.    sutured wound edges/tissue loss and slough in the palatal tissue. He is  not a candidate for closure immediately. It is preferable to wait until  complete healing and schedule the procedure electively. (b) OPG of the  above case showing the root in the sinus cavity    4. Nasal decongestant drops to increase the drainage of the  sinus and open up closed ostium.   5. Antihistamines to decongest the sinus and also to avoid  sneezing, which may increase the sinus pressure and have  a deterrent effect on the success of the closure.    The antral regime may be continued for a few days  (3-7 days) after the closure as well to ensure a trouble-free  healing. After closure, the patient is advised to have certain  restrictions in the initial healing phase, in order to avoid  break down of the closure, 1.e.   2. If coughing cannot be avoided, do cough with mouth open.   3. Avoid smoking to avoid negative pressure in the oral  cavity.   7. It would be preferable to review the patient at least  once in 2—3 days during the initial healing period to  assess the healing status. The clinician may irrigate the  surgical site with saline removing the collected debris/  slough if any.   8. Some author’s advice to keep a pre-fabricated custom-  made acrylic splint at the site of closure as a support.  However, there are thoughts that the splint may irritate or   traumatize the sutured edges on the alveolar ridge and be a    At times, the antral lavage is done daily or on alternate days  along with the antral regime to clear the exudate from the    sinus. The presence of exudate/pus can be seen as a ‘fluid  level’ in a paranasal sinus X-ray, or there may be generalized  opacification of the involved sinus in the X-ray. The closure  is attempted, only when the surgeon feels that the antral  washouts are clear, and the sinus is reasonably healthy to  receive the closure.   ENT books describe different methods of antral lavage,  either via a Caldwell Luc opening or via the nasal meatus  depending upon the case. However, from an oral surgical  perspective for most cases, antral lavage may be done via the  existing OAF (Fig. 24.19). 10-20 ml of saline is flushed  through the OAF via a syringe, and patient is seated at a for-  ward position with head bent down. The washout will flow  out through the nasal cavity or via the OAF, and the washout  is collected in a tray positioned before the patient. In the ini-  tial days of lavage, the washout will have a cloudy/opaque  appearance, and after few days, we should expect the wash-  out to be clear.    This procedure was developed independently by two  surgeons, George Caldwell in New York (1893) and Henry  Luc in Paris (1897) (Box 24.4).    Box 24.4 Technical Note: Caldwell Luc Procedure in Oral  Surgery Context   e Horizontal U-shaped incision in the vestibule-few  mm above gingival attachment or   ¢ Mucoperiosteal flap-raised upward to the point of  emergence of the infra-orbital nerve.   e Chisel or dental bur is used to create a window on  anterior wall of sinus above root of teeth of that area.   e Soft tissue placed and sutured over bone with  resorbable sutures.    Fig. 24.20 Clinical picture showing a Caldwell Luc procedure via  extended crevicular flap for removal of a root in sinus. Note the defect  made in the anterior maxilla wall    It involves making an opening in the anterior wall of sinus  in the canine fossa region, to get good access to the sinus.  The procedure is done either via a sublabial incision or by  extended crevicular incisons (Fig. 24.20). In the context of  OAF, this approach has relevance when combined along with  the closure of OAF. The approach may be used to retrieve  root tip or to surgically treat chronic sinusitis as in polyps. In  combined cases, the extended crevicular flap with adequate  releasing incisions may be used to remove root tip and may    be used as a buccal advancement flap with or without buccal  fat pad graft for the closure of OAF.    1. Recovery of entrapped foreign body from the sinus cavity  proper, displaced tooth or root.    Such cases are more difficult to manage and will need a com-  bined oral surgery/ENT approach. There may be severe  antral lining hyperplasia and lack of natural drainage by  blockage of the ostium or antral polyps. The line of manage-  ment has to be decided on an individual basis. Occasionally,  the sinus problem may have to be addressed before attempt-  ing a closure, which may require two surgeries. Sometimes,  the oral surgeon may be in for a surprise during OAF clo-  sures to see fungal balls in the sinus. The reasons for c/c  sinusitis should be evaluated and addressed accordingly.   The second option is to attempt closure along with the  treatment of chronic sinusitis. In such cases, a formal  Caldwell Luc opening may be made to remove the unhealthy  lining. If that is the case, the buccal flaps are modified as per  requirement to get a tension-free closure at the OAF site. In  situations where FESS is used, oral surgeon can visualize the  sinus and see the OAF from the nasal/antral side. The use of  FESS gives a two pronged approach, i.e. the unhealthy lining  from the antral side of the OAF can be removed and closure  performed. This means that in OAF with c/c sinusitis, a gen-  eral anaesthesia will be necessary, unlike uncomplicated  OAF cases where most of the established techniques may be  done under local anaesthesia if required.   Adams (2015) [51] has reported on the success of using  combined FESS and BFP closure. The sequence followed by  Adams included pre-operative computed tomography, antibi-  otic therapy, exploration and removal of sinus pathologic tis-  sues, rotation of a pedicled fat pad graft into the oral opening,  repair and closure of oral mucosa, exploration of involved  sinuses with excision of sinus and nasal tissues necessary for  establishment of osteomeatal drainage and follow-up.   Cases of fulminant pansinusitis have been encountered  arising from long-standing untreated OAF. This involves the  contralateral side, and such cases need a comprehensive joint  approach with the allied specialities, before embarking upon  closing the OAF.    Fig. 24.21 Coronal slice CT scan, showing hyperplasia of sinus lin-  ing, especially on the right side, where the OAF can be Appreciated    ae : Ll ~=  ©Association of Oral and Maxillofacial Surgeons of India    Fig. 24.22 Coronal CT scan of a 50-year-old male, who had normal  extraction of upper left second molar, which was followed by break  down of clot and resulted in OAF. He later developed infection with pus  discharge from socket. CT scan shows the fully opacified left sinus.  Under GA (joint case with ENT surgeon), a 2 layer BFP closure was  done, accompanied by FESS and Caldwell Luc approach via extended  mucoperiosteal flap. Intraoperatively, the sinus was filled with fungal  balls, which could have been the cause for the formation of OAF    Figures 24.21, 24.22 and 24.23 show coronal CT slices of  different case scenarios where OAF was accompanied by  chronic sinusitis.   In Video 24.1, the video contributing Surgeon has man-  aged an OAF associated with chronic sinusitis, by a combi-  nation of Caldwell-Luc procedure, Nasal antrostomy, and  layered closure by buccal advancement flap. Layered closure  has been achieved by suturing of sub mucosa and mucosa of  the advanced buccal flap.    Fig. 24.23 Coronal CT view showing pan sinusitis in 58-year-old  male, who developed an OAF in the anterolateral wall of maxilla from  a previous failed surgery, probably for a cyst enucleation in the maxilla  (previous records not available)    The ostium of maxillary sinus opens into middle meatus,  which is at a higher level than the sinus floor (Fig. 24.24). In  normal healthy sinus, this is not a problem as the normal cili-  ated respiratory epithelium will help in the drainage. Briefly  saying, nasal antrostomy is a procedure where an opening is  made in the inferior meatus, either from the nasal or sinus  side to facilitate drainage of sinus in a dependent manner.  Nasal antrostomy is an adjuvant procedure, which can be  done along with cyst enucleations of the sinus or in selected  cases of OAF closure. The need for nasal antrostomy has  decreased now with changing philosophies, the advent of  FESS and the importance given to the osteomeatal complex.  Recent studies (Huang YC [52] 2012) have also proved the  decreased need for inferior meatal antrostomy following  sinus surgeries.   For elaborate details of Caldwell Luc and nasal antros-  tomy procedures, readers are advised to refer the concerned  speciality books.    In situations where a fragment of a root or a full root or roots  is missing during extraction of maxillary premolars or  molars, the surgeon will have to take certain decisions and  some questions should flash through his or her mind.    (a) Should I locate the root tip and where should I look for it.   (b) If located, should I attempt to retrieve it or decide to  leave it.   (c) Will the root retrieval necessitate GA and if so when to  schedule the procedure.   (d) Should the root tip left behind be removed later at an  elective date or not removed and remove only if any  symptoms occur.   (e) If the root has gone into the sinus, an OAC would have  been formed. Should I remove the root tip and close the  OAC, or should I leave the root tip and close the OAC or  plan for a combined removal of root and OAC/OAF clo-  sure later on an elective date.    While attempting removal of a root tip, if it suddenly disap-  pears, make sure that the tip is not there in the following places.    If the root tip is assumed to be pushed upwards into the  sinus cavity, the tip may lodge in the following areas:    (a) A fenestration would have happened in the apical labial/  palatal alveolar bone, and the tip would be lodged between  the labial/palatal alveolar bone and the mucoperiosteum.    (b) Rarely, the tip would have perforated the buccal muco-  periosteum and get lodged near the buccinator muscle.   (c) Tip would be lying between the sinus lining and the  sinus floor. In strict sense, it may be assumed that an  OAC is not formed as the integrity of the membrane is  not lost.   (d) Tip may have pierced through the sinus membrane  and entered the sinus cavity (theoretically causing an  OAC).    X-rays in two different planes (IOPA/OPG/Occlusal) will  be helpful to give an idea about the root tip position espe-  cially when it is inside the sinus. When the root tip is retain-  ing its lamina dura on an IOPA x-ray, it may be assumed that  it is still lying within the bone and not have entered the sinus  cavity. Paranasal sinus view will confirm that the root is in  the sinus and CBCT also may be helpful in localization.   In situation (a), Transalveolar approach will help in  removing the root tip.   In situations (c) and (d), the following methods are sug-  gested in the literature and the resulting OAC is closed pri-  marily or at a later stage depending upon the surgeons’ choice.    1. If the root tip is visible through the socket, it is gently  removed with the help of probes/tweezers/mosquito  forceps.   2. If not visible, the sinus is flushed with saline and it is  hoped that the root tip will float in the sinus. A metal suc-  tion tip is placed at the socket apex, and the clinician may  expect the root tip to be lodged at the end of the suction  tube.   3. A gauze piece may be inserted into the sinus via the  socket and pulled out in a jerky fashion hoping that the-  root tip will get entangled in the gauze piece.   4. The tip may be removed through the socket, by enlarging  the communication. This may require removal of the  inter-radicular bone and visualizing the sinus to get better  approach, vision and access. This technique is usually  successful, but the flip side is that the chance of failure of  closure is increased as the surgeon is dealingwith a com-  munication of considerable size (Fig. 24.25).   5. Another option would be to remove the root via the  Caldwell Luc approach or FESS. This is usually done on  an elective basis.    It is important to say a few words on this topic at this  juncture, even though there may be difference of opinion  and contentions on the points given below. These can be  applied to all root tips being left behind. If the clinician    Fig. 24.25 In this case, the surgeon is attempting to remove the root in  sinus, which has been dislodged superiorly during the extraction, by  enlarging the socket and an extended mucoperiosteal flap has been  raised. The sinus can be visualized via the socket. This technique is usu-  ally not recommended as the resulting OAC will be of considerable  size; however, in this case, the OAC was closed by a 2 layer BFP  technique    feels that removing a fractured root tip of an upper premo-  lar/molar is beyond his or her level of competence or there  is a possibility of causing OAC, which he or she cannot  deal primarily, the root tip may be left behind in the fol-  lowing situations;    1. The root tip is less than 2-3 mm in length.   5. Attempts at removal of the tip may cause more damage  and surgical procedures when compared to the benefits of  removal.    The patient should be well-informed about this situation  and should be informed that the tip may be removed later if  they wish so. Adequate documentation in the form of x-rays  and clinical notes is mandatory, in order to follow up the case  and to avoid any future medico-legal issues.    Clinical Scenario 2  An interesting clinical Scenario for the benefit of young  clinicians.   A 40-year-old female had routine extraction of root  stumps of upper left first molar. A pre-operative IOPA was  not taken. After extraction, to the surprise of the dental sur-  geon, there was pus discharge through the socket (See  Fig. 24.26a and b)    The probabilities are that either there was a pre-exist-  ing sinusitis, which was unrecognized, or the root stumps  caused the odontogenic infection to spread into the  sinus.   There may be different opinions, but the following sequence  may be followed in this particular case, which is given as  clinical pearl section below.   e Decide whether there is need for Caldwell luc/  FESS/nasal antrostomy after sinus evaluation.    Clinical Scenario 3 (Fig. 24.27a, b, c and d)  Another interesting clinical scenario, which I came across in  a maxillofacial trauma case recently, is given as follows:   A 36-year-old male sustained RTA and facial fractures as  seen in Fig. 24.27a and b. Tooth numbers 15 and 16 (upper  right first pre-molar and molar) were avulsed with commi-  nution of labial cortical plate and the alveolar process creat-  ing an oroantral communication (Fig. 24.27c). You can  appreciate the bubbling of mucus at the OAC site. CT  showed bilateral haemosinus, fracture maxilla and mandi-  ble, The right posterior alveolar segment containing 17,18  (upper right second molar and third molar) was mobile and  extruded due to a posterior right parasagittal fracture of the  maxilla.   The upper sub-labial incision, given for the maxillary  fracture exposure, was curved down distal to 14 (upper right  first pre-molar) and continued as a full thickness crevicular  mucoperiosteal flap. The distal release was not given, for  fear of jeopardizing the vascularity of the posterior alveolar  segment. The BFP was mobilized in the conventional way  (Fig. 24.27d), and a good two-layered primary closure was  attained after reduction and fixation of the fractures. The  posterior alveolar segment had to be fixed to the main seg-  ment via transosseous wiring. This segment was extruded,  and to achieve healing and occlusion, post-operative IMF  was given. This particular patient was on Ryles Tube feeding  for few days, mainly due to other injuries and tracheostomy,  which would have helped in the good healing of the OAC  closure.    Fig. 24.26 (a) Surprise finding of pus from socket after extraction of upper left first molar root stumps, (b) PNS view taken after extraction shows    Fig. 24.27 (a, b, c and d) OAC following maxillofacial trauma (see the text for details)    The clinician should be cautious of not deliberately causing  an OAC while performing exodontia and dentoalveolar pro-  cedures in maxillary posterior region. An OAC should be  ruled out in suspected cases, and if it occurred, necessary  steps should be taken to ensure a closure primarily if possi-  ble. Even as this chapter is going to the publishers, clini-  cians are exploring the possibilities of new techniques, of  which the flapless closure techniques of acute OAC seem to  be quite promising. Closing OAC with PRF membrane/col-  lagen composite [53, 54] offers easier, less traumatic meth-  ods to close OAC, which may even obviate the need for  special surgical expertise. Materials like acellular dermal/    bone matrix are also being used recently [55] However, only  time will prove the obduracy of these path breaking  methods.   Visscher [56] in a retrospective study of 308 oroantral  closures found that about 10% needed re-operation, and  patients with maxillary sinusitis had 15 times higher risk of  developing a recurrence.   Dealing with OAF cases is interesting in the sense that  it involves assessing the health of sinus and choosing and  performing the most suitable surgical technique, most of  which are fine surgeries. It is indeed rewarding to see a  symptom-free patient with a well-healed OAF closure  site.    Eberhardt JA. A computed tomographic study of the distances  between the maxillary sinus floor and the apices of the maxillary  posterior teeth. 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Open Access _ This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.  org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropri-  ate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.   The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in  a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.    There are infinite opportunities in dentistry to damage the  trigeminal nerve. Nerve damage from surgery can cause  chronic post-surgical pain; however, this is limited in den-  tistry as a result of Local anaesthetic (LA) infiltration injec-  tions but more commonly associated with injuries to the  nerve trunks of division two and three caused by implants,  endodontics and third molar surgery (or other high-risk  extractions). Fortunately, painful post-traumatic trigeminal  neuropathy (PPTTN) is rare in dentistry compared to other  common general surgical procedures where 20-45% of  patients experience persistent pain after surgical limb ampu-  tation, thoracotomy and breast surgery. This chapter high-  lights the prevention (using risk assessment, optimal surgical  techniques, early post-surgical follow-up protocols and other  strategies) and optimal management of trigeminal nerve  injuries.   Trigeminal nerve injury (TNI) associated with chronic  pain is the most problematic consequence of dental surgical  procedures with major medico-legal implications [1]. The  incidence of lingual nerve injury has remained static in the  UK over the last 30 years, but is increasing in the US, as is  the incidence of inferior alveolar nerve injury in the UK,  with the latter being due to implant surgery and endodontic  therapy [2]. Third molar surgery-related inferior alveolar  nerve (IAN) neuropathy or inferior alveolar block injections  are usually temporary but can persist and become permanent  (by definition at 3 months). There are rare reports of resolu-  tion of implant and other cause-related IAN neuropathies at  over 4 years, [3] but these are not similar reports of other  peripheral sensory nerve injuries [4~7]. In dentistry, fre-  quently, a treat delay is 3-6 months [5], which is inappropri-  ate when compared to other peripheral sensory nerve injuries  where immediate repair and exploration are recommended.  We now understand that known or suspected, restorative    T. Renton   Oral Surgery, Kings College London, London, UK  e-mail: Tara.renton @kcl.ac.uk    © The Association of Oral and Maxillofacial Surgeons of India 2021    (endo and implant)-induced nerve injuries require interven-  tion ideally immediately, within 30 h or within 3 months,  dependent upon the mechanism of injury, to optimize resolu-  tion from injury and prevent the permanent central and  peripheral changes within the nervous system [6, 7].   Paraesthesia is often inappropriately used in the dental  literature to mean neuropathy. However, paraesthesia is only  a descriptive term, meaning altered sensation and not a diag-  nosis. When sensory nerves are injured, a neuropathy (mal-  function) may arise, and this may be painful or non-painful.   The trigeminal nerve has the largest representation in the  sensory cortex, reflecting the disproportionate sensory input  from the orofacial region. It protects vital structures that  underpin our very survival, providing sensory supply to the  eyes, airway, brain, mouth and ears. It is no ‘wonder’ that  when the threat or actual pain arises in the trigeminal nerve  area that the patient is neurophysiologically wired to ‘run for  the hills’ from the dental chair. Latrogenic (caused by sur-  gery or medicine) trigeminal nerve injuries (TNIs) result in  70% pain in patients seen seeking treatment on our clinic [7].  The ongoing or evoked pain results in interference with eat-  ing, speaking, sleeping, applying makeup, shaving, kissing,  tooth brushing and drinking; just about every social interac-  tion, we take for granted. As a result, these injuries have a  significant negative effect on the patient’s self-image, quality  of life and psychology [7].   With the increasing age of the patient, the time elapsed  since the injury and the proximity of the injury to the cell  body (the more proximal lesions have a worse prognosis)  will dictate the persistence of any peripheral sensory nerve  injury.   There are many non-surgical causes for trigeminal neurop-  athy, and these must be borne in mind if the patient presents  with an unclear onset of motor or sensory neuropathy [8].   Sensory nerve injuries caused by implant and endodontic  treatments are mainly permanent. Only LA nerve injuries  have a 75% likelihood of recovery and lingual access third  molar surgery and have 90% potential for recovery [9].    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1 -15-1346-6_25    Referral of patients with these nerve injuries before 4 months  [2] is too late for optimal resolution or management as infe-  rior alveolar nerve injuries often require an immediate  implant or endo-treated tooth removal within 24—30 h. We  now understand that after 3 months, permanent central and  peripheral changes occur within the nervous system subse-  quent to injury, which are unlikely to respond to surgical  intervention [10].   Nerve damage is likely to result from a combination of  poor risk assessment, poor technique, lack of recognition  and the acute management of intra-operative and _ post-  operative signs of neuropathy. Risk assessment involves the  patient selection, pre-operative planning, both clinical and  radiographic, appropriate selection of implant site and type  (width and length) and suitable treatment protocol and  follow-up.   It is important that the clinician is familiar with the nerve  injury risk factors, specific for each of the types of invasive  procedures. For example, in the case of protrusion through  the IDC and resultant direct IAN mechanical injury by  implant drill, a “sudden give” or an “electric shock” type  feeling, even with local anaesthesia working, is reported by  most of the patients seen in our clinic with post-traumatic  neuropathy. This should result in the clinician stopping sur-  gery, not reaching for another LA block injection and reas-  sessing their surgical position with regard to the injured  nerve.   The problem with implant-related nerve injuries is that  they are entirely avoidable as this is elective surgery, thus  negligent, and likely to be permanent and painful for the  patient [11]. In addition, persistent nerve injuries cannot be  resolved. Surgical intervention for hypoaesthetic nerve inju-  ries does not return the patient to normality [10], and surgery  for patients with pain and hyperaesthesia is not appropriate  as the pain is not abated and patients are faced with long-  term anti-epileptics or anti-depressants for chronic pain [11].   When assessing patients with surgically induced nerve  injuries, we recommend a more holistic approach in assess-  ing patients with nerve injury [8]. The definition ICHD 3  (International Craniofacial pain and Headache Disorders) of  painful post-traumatic trigeminal neuropathy (PPTTN)  includes development of neuropathy within 3 months of  injury with sensory neuropathy and pain. The author believes  that the neuropathy develops immediately after trauma,  unless related to endodontic procedure where there may be a  2-3 days delay in neuropathy development. Features of iat-  rogenic trigeminal nerve injury worthy of assessment include    ¢ Focal sensory neuropathy (mostly present). There is  almost always an area of abnormal sensation (neuropathy  with the exception in Trigeminal neuralgia which is NOT  post-traumatic), and the maximum reported pain is asso-  ciated with the area of sensory deficit (i.e. suffering from    a mixture of pain, numbness and altered sensation). This  is an important diagnostic feature for sensory nerve  neuropathy.   e Pain discomfort, altered sensation and numbness (anaes-  thesia). Neuropathic pain is commonly present with allo-  dynia (pain on non-noxious stimuli), hyperalgesia  (increased pain to noxious stimuli) and hyperpathia (con-  tinuous altered sensation or pain after stimulation ceases).  In 50-70% of patient reports, a combination of numbness,  altered sensation and pain is experienced, the pain may be  spontaneous ongoing pain, which often had a burning  character, spontaneous shooting or electric shock-like  sensations (neuralgia) [7]. Evoked pain due to touch or  cold often leads patients to have difficulties with daily  function, such as eating, socializing, kissing, speech and  drinking. As a consequence, patients are often anxious  and tearful and had psychological repercussions of sur-  gery. These symptoms were often compounded by the  lack of informed consent, which was given by only 30%  of patients, most of whom were not specifically warned  about potential nerve injury [7].   ¢ Daily function problems (drinking, kissing, eating, sleep-  ing, speaking, tooth brushing and avoidance) [12],   ¢ Psychological (anxiety, stress, post-traumatic stress disor-  der and anger) [12].    The following sections address the prevention and man-  agement of trigeminal nerve injuries related to    Local block injection-related nerve injury is an acknowl-  edged complication in relation to surgery [13]. Dentistry is  the only speciality that still trains clinicians to aim for nerves  rather than avoiding neural contact (often using ultrasound),  which likely explains the continued prevalence of LA-related  nerve injuries in dentistry. All other block injections are  undertaken using ultrasound in order to avoid nerve injury.  One report highlights that the prevalence of IDB-related  nerve injuries in UK General dental practise is 1:14,000  blocks, or 1:56 K IDB patients experience permanent lingual  or inferior alveolar nerve injury of which this 25% of nerve  injuries are permanent [9]. It is estimated that every practis-  ing dentist will experience causing 4—6 temporary nerve  injuries and one permanent nerve injury related to IDBs dur-  ing their working life based upon current practice.    Nerve injury may be due to many causes including physi-  cal (needle, compression due to epineural or perineural  haemorrhage), ischaemic or chemical (haemorrhage or LA  contents). The site of the injury may also vary and combine  peri-, epi- and intra-neural trauma causing subsequent haem-  orrhage, inflammation and scarring, resulting in demyelin-  ation (loss of nerve lining) [14]. Only 1.3-8.6% of patients  get an ‘electric shock’ type sensation on application of an  IAN block and 57% of patients suffer from prolonged neu-  ropathy having not experienced the discomfort on injection,  and thus, this is not a specific sign [15]. Routine practice in  Germany includes warning patients of potential nerve injury  in relation to dental block injections. Risk factors for persis-  tent local anaesthesia nerve injuries are summarized in  Table 25.1.   The lingual nerve (LN) is at increased risk of permanent  injury compared to the IAN during local anaesthesia, possi-  bly related to the reduced number of fascicles in the LN com-  pared to the IAN [16].   Higher concentration agents are more neurotoxic and,  therefore, more likely to cause persistent inferior dental  block (IDB)-induced nerve injury [17-22]. Irrefutably,  Schwann cell death is related to increased concentration and    In order to minimize complications related to dental LA, you need to  consider modifying the following risks:   ¢ Block anaesthesia: nerve block injections should be undertaken  without intent on direct ‘hit’ of the nerve. 60% of patients who  experience the ‘funny bone’ neuralgia due to the IDB needle  being placed too close to the lingual or inferior alveolar nerves  experience persistent neuropathy  Lingual nerve > IAN: is this technique related or anatomically  related (less fascicles in LN lower capacity for recovery).  Perhaps, the direct IDB approach may place the lingual nerve at  increased risk compared to the indirect technique  Concentration of LA: any increased concentration of any agent  leads to increased neural neurotoxicity  Volume of LA: there is no evidence to support this suggestion,  but all chemicals are neurotoxic, and depending upon the  proximity, LA concentration and neural damage, additional  volume would add to potential neurotoxicity  Multiple injections: second or subsequent injections that  impede directly on or in neural tissue may not be associated with  the usual ‘funny bone’ neuralgic pain. Thus, the patient does not  self-protect as effectively possibly rendering the nerves more at  risk of direct damage  Severe pain on injection: 60% increased occurrence of  persistent neuropathy after IDBs  Type of LA: agent bupivacaine most neurotoxic of all LA agents  Type of vasoconstrictor? The role of vasoconstrictor in nerve  damage is unknown  Sedated or anaesthetized patients? There is no evidence to  support unresponsive patients, who are less likely to protect  themselves when neuralgia (funny bone reaction) occurs as the  IDB needle encroaches too close to the nerve  Lack of LA aspiration? There is no evidence to support that  aspiration during IDB results in lower persistent neuropathies,  but a pragmatic view may infer less chemical injected intra-  neurally will cause less chemical nerve injury    time exposure to LA [22]. Articaine is provided in 4% con-  centration and Lidocaine in 2% solution in most countries. A  recent prospective randomized study reports that there is no  benefit or using 4% Articaine IDBs compared to 2%  Lidocaine [23], which is substantiated by other evidence  [24-27]. Thus, logically why would anyone use a higher  concentration agent for an IDB when there is no increased  efficacy and higher risk of nerve injury? [28]  Intra-operatively, all clinicians should document unusual  patient pain reactions occurring during injections or surgery  (such as sharp pain or an electrical shock-like sensation), as  neuralgia during injections is associated with increased per-  sistence of nerve injury [15]. Thus, it is important that the  clinician uses an appropriate LA method to prevent proxim-  ity of the injection/surgical instruments to the IDC, for  example, infiltration anaesthesia for implant surgery.    Daublander et al. reported that in a 2014 [23] survey of  German dental LA practise, 74% were using infiltration den-  tistry routinely and rarely giving IDBs (personal communi-  cation). Improved patient comfort is reported by patients  with preference for having full lingual sensation and shorter  duration LA anaesthesia after dental treatment.   There is further evidence to support the notion of infiltra-  tion dentistry can be successful in many aspects of dentistry    ¢ Maxillary infiltration anaesthesia  Studies report that 4% Articaine to be more effective than  2% lidocaine for lateral incisors but not molars [25], dif-  fering from other reports [23, 25]. A recent randomized  controlled trial reported a statistically significant differ-  ence advocating the use of 4% Articaine in place of 2%  lidocaine for buccal infiltration in patients experiencing  irreversible pulpitis in maxillary posterior teeth [24, 26].  This has been superceded by a metanalysis that reports  there is no advantage in using 4% Articaine for maxillary  infiltration anaesthesia and that 2% Lidocaine is suffice  for dental interventions.   ¢ Pulpal anaesthesia in the anterior mandible compared to  inferior dental block (IDBs) [25].  Meechan provides evidence supporting the significantly  increased rates of pulpal anaesthesia using infiltration  anaesthesia when compared to IDB anaesthesia particu-  larly for premolar and incisor teeth (Fig. 25.1).   ¢ Pulpitic mandibular molars in adults [23, 25, 29, 30].  A recent systematic review reports that Articaine is 3.4  times more effective for pulpitic mandibular molars when  compared to lidocaine, but there is no difference between  Articaine and Lidocaine maxillary infiltrations or IDBs  [31].    Maxillary dentistry can be  performed using Lidocaine 2%  with adrenaline for all procedures  Buccal infiltration with intra-  septal injections    Mandibular incisors, canines and premolars for perio, restorations or implants and Endo  Submucosal infiltration in in front or behind mental nerve area (NOT direct into nerve) Articaine 4% buccal  infiltrations and extractions add lingual infiltration and or intra-ligamental   Paedodontic extractions do not require IDBs as the bone  is very porous and susceptible to absorption of infiltrative  anaesthesia.   Several reports of supra-periosteal infiltration anaesthesia  not only are sufficient for posterior mandible implant sur-  gery but also may be protective of the IAN [33].   The standard care for periodontal and implant surgery is  infiltration LA [34].    Thus, prevention of LA nerve injuries is possible  and some simple steps may minimize LA-related nerve  injuries:   e Avoid high concentration LA (Articaine 4%) for  block injections and for ID blocks (use 2%  Lidocaine as standard) as the efficacy is equal.   e Avoid block anaesthesia by using Infiltration den-  tistry and, thus, prevent LA-related nerve injury,  for which there is no cure.    Evidence base remains limited for managing dental  LA-related nerve injuries; we only know that 25% are  permanent and that there is no ‘magic bullet’ to fix them.  A sit and wait approach has to be adopted with reassur-  ance of the patient and therapeutic management of their  symptoms    HOMECHECK—If you cause pain during an IDB  injection in your patient, do follow them up the next  day and check they are OK. If the patient reports  numbness, altered sensation and/or pain, reassure  them.  Continue to support, reassure your patient and advise  them to visit to confirm the presence of neuropathy. If the  neuropathy affects most of the dermatome + associated  with severe neuropathic pain, nerve injury must be sus-  pected. Reassure your patient that 75% of these injuries  resolve.   — High-dose oral NSAIDs (400-800 mgs Ibuprofen  PO QDS) for 2 days only. Bandolier Oxford league  table summarizes the optimal analgesia for post-  operative pain, and combined Ibuprofen and  paracetamol have the smallest number needed to  treat.    — GMP prescription for Prednisolone 5 day step down  does 50-40-30-20-10 mg PO (not for patients with  contraindications for steroids or NSAIDs).   — Vitamin B complex (Riboflavin 400 mg once daily for  maximum of 3 months plus other Vit B complex).   e Arrange a review of the patient. All advice is summarized  on the Trigeminalnerve.org.uk website.  e¢ Long-term management of patients with non-resolving  LA nerve injuries. The reality for these patients is that if  they have persistent neuropathic pain and have to be  treated as such with psychological and medical manage-  ment. Topical local anaesthetic (Lidocaine 5%) patches  may assist the patient in sleeping and playing sports in  cold weather [35]. Psychological interventions play a sig-  nificant role in managing these patients, and recommen-  dations for treatment of trigeminal neuropathic pain are  also well described by Renton & Zakzrewska [36].    25.3 Implant-related Nerve Injuries  Implant-related IANI’s incidence varies from 0-40% [37].  Two recent studies highlight persistent neuropathic pain due  to implant IANIs [38, 39]. Prevention of nerve implant IANIs  can be attributed to the avoidance of direct damage to the  Inferior dental canal (IDC) during preparation [40]. A good  clinical and radiographic pre-assessment protocol is required  to mitigate damage due to proximity of implant bed prepara-  tion to the inferior dental canal (IDC) and are recommended  [41, 42]. The risk factors for implant nerve injury are sum-  marized in Table 25.2 [41, 42, 45-52].   A limited window is available to maximize inferior alve-  olar nerve injury resolution in relation to dental implants,  endodontics and mandibular wisdom teeth. A report illus-  trated that early removal of implants (within 30 h) may  maximize neuropathy resolution; however, the evidence  remains weak [37]. Prevention of implant-related nerve  injuries includes;   — extra diligence in planning implants in the parasym-  physeal region near the mental nerve (loop and incisal  branches),   ¢ Inadequate informed consent-all options provided and related  risk benefit for each option of treatment. Implants are elective  treatment. Sublingual haematoma that can require the need for  tracheostomy post-implant treatment and rare events of death   ¢ Poor planning in risk assessment and positioning the implant. A  sectional DPT is recommended as a minimum for mandibular  implant planning. If there is limited bone depth, a CBCT may be  used to quantify and qualify bone density and volume.  The clinician must be able to read and analyse the CBCT,  depending upon technicians, software or radiologist specialist  (who are not present with you intra-operatively)   — Know where the nerve is. Nerve localization, risk factors  when assessing IAN position (mental loop, characteristics of  IAN position in various sites of mandible) and  Parasymphyseal zone that is of high risk.   — The accuracy of estimating the position of the IDC based on  plain films or CT scans is highlighted in the radiographic  assessment section   — Safety zone- the recommendation is 2 mm (by ITI and ADD),  which may be insufficient considering that most-implant drills  are 1.5 mm longer than implants. This increases the risk  perforation of a canal surrounding IDC or even direct  perforation and damage to the nerve   ¢ Selection of implants 10 mm + (short implants <8 mm to  simplify procedure and minimize morbidity)   ¢ Local Anaesthesia (use infiltration LA techniques to allow  patients to notify the surgeon or intraoperative neuralgia; if pain  is reported, intra-operatively stop surgery and reassess  preparation depth and width)   ¢ Prompt management of neuropathy (removal of implant if  indicated) [44]   — In such situations, stop surgery, do not reach for more  LA and reassess your surgical position,   ¢ take appropriate post-operative periapical radiographs  (CBCTs not indicated) to confirm proximity and/or  breech of the inferior dental canal or around the mental  foramen before patient discharge.   e If nerve injury is suspected or identified, the patient  should be informed, Immediate removal of the implant  should be arranged and appropriate medical management  should be instituted with arranged review with the treat-  ing clinician and specialist if required.   ¢ HOMECHECK -Contact must be made by the clinician  and the patient between 6 and 24 h after surgery to con-  firm that the patient is experiencing any persistent neu-  ropathy. This builds on the relationship of the clinician  with the patient, which will be premised upon good con-  sent process.   — Continue to support and reassure your patient and advise  them to visit return to your clinic. If the neuropathy  affects most of the dermatome + associated with severe  neuropathic pain, nerve injury must be suspected.   — Say SORRY this is NOT an admission of guilt. When  neuropathy is confirmed, check who you must notify  as in many countries, [ANIs are reportable events. It is  essential to be honest with your patient.   — Additional scanning or radiography may not be essen-  tial. Post-traumatic neuropathy is a clinical diagnosis.  You will already be aware of the proximity of the  implant bed to the IDC, and whether there was likely  breach into the IAN canal.   — If nerve injury is suspected, the implant must be  removed within 24—36 hours of placement in order to  maximize recovery from nerve injury [37].   — Initiate medical management (recommended for other  peripheral sensory nerve injuries).   High-dose oral NSAIDs (400-800 mgs Ibuprofen PO  QDS) for maximum 2 days.   GMP (General Medical Practitioner) prescription for  Prednisolone 5 day step down does 50-40-30-20-  10 mg PO (not for patients with contraindications  for steroids or NSAIDs).   Vitamin B complex (Riboflavin 400 mg once daily for  a maximum of 3 months plus other Vit B  complex).   e Long-term management of patients with non-resolving  nerve injuries. The reality for these patients is that if they  have persistent neuropathic pain and have to be treated as  such with psychological and medical management.  Psychological interventions play a significant role in  managing these patients, and recommendations for treat-  ment of trigeminal neuropathic pain are also well  described by Renton & Zakzrewska [36].    The nerves at risk of damage in mandibular third molar  extraction are the terminal nerves of the third branch of the  trigeminal nerve [53, 54], i.e. the inferior dental nerve (IDN)  and lingual nerve (LN). The reported risk of neurosensory  deficit ranges from 0.26 to 8.4% for IDN [55] and from 0.1  to 22% for LN [ 7]. Patients with IDN injury suffer from  paresthesia, anaesthesia or dysesthesia in the lip, chin or gin-  giva on the affected side, while patients with LN injury have  a sensitivity deficit at the homolateral half of the tongue,  with or without taste alteration [ 7]. Transient and permanent  lesions should be differentiated; permanent lesions often  remain after 6—12 months, and spontaneous recovery cannot  be expected in these cases [ 56].   Damage to the LN or IDN during third molar extraction is  among the most frequent causes of litigation in dentistry  [57]. Highly varying results have been published by numer-  ous studies on risk factors related to neurosensory deficit in  lower third molar surgery. The objective of a recent literature  review was to identify and analyse studies on factors related  to IDN and/or LN injury in lower third molar extraction,  allowing clinicians to take appropriate measures to minimize  this risk [58]. Several radiological risk factors have been  identified that increases the risk of nerve injury during  removal by ten-fold (from 0.2 to 2% permanent injury and  2-20% temporary nerve injury) [59, 60].    Factors that may be implicated in nerve injury after lower  third molar surgery were classified into four groups:    A recent review included three cohort studies and various  randomized clinical trials (RCTs) on the influence of diag-  nostic radiographic techniques. They generally reached simi-  lar conclusions, finding that the non-utilization of CBCT was  not an additional risk factor for nerve injury in patients  examined by conventional panoramic radiography [61-63].  Korkmaz et al. [64] and Lee et al. [65] reported a lower  frequency of transient but not permanent IDN damage when    CBCT was also used. This may be because in cases where  the relationship between third molar and the IDN is doubtful,  there is likely to be no direct contact and the injury would  result from pressure due to haemorrhage or haematoma so  that the association would be less detectable on panoramic  radiology. In contrast, cases of direct contact are readily  observed using both radiographic techniques.    Various authors reported a significantly lower frequency of  nerve injury with younger age. [66-70] Thus, no cases of  nerve injury were observed among patients under 23 years of  age in the cohort study of 1050 patients by Zhang et al. [ 71],  while Kjolle et al. [66] confirmed a significant association  with age (p = 0.007), finding a higher frequency of permanent  injury in patients over 30 years of age. These findings may be  attributable to an increased difficulty of the surgery at older  ages due to a greater likelihood of hypercementosis, lower  bone elasticity and, above all, completed root formation, in  addition to lesser vascularization, reducing the regenerative  capacity of the nerve. Nevertheless, other researchers found no  significant relationship with age [72] although the sample  sizes were smaller than that in the aforementioned studies. All  reviewed articles observed a higher frequency of nerve inju-  ries in females [62] although this difference was only statisti-  cally significant (p = 0.005) in the multiple logistic regression  analysis of 320 cases conducted by Selvi et al. [68] Gender  differences have been attributed to the generally smaller man-  dible of females, implying a smaller gap between third molar  root and IDN.    The mandibular canal is evidently more susceptible to nerve  injury with greater depth and, therefore, closer proximity of  the impacted third molar, reducing the surgical accessibility  and visibility. A statistically significant association was  demonstrated by all three articles that studied this risk factor  [62]. A higher risk of IDN injury was associated with mesio-  angular impactions and with horizontal impactions [62], but  these associations were not found to be statistically  significant.    In 1990, Rood and Shehab [59] proposed seven radiological  signs identifiable by panoramic radiography, which indicate  a close relationship between lower third molar and IDN: root  narrowing, root darkening, apex darkening and bifid images,    changes in root direction, dental canal narrowing, dental  canal diversion and interruption of the white line of the den-  tal canal. Only four of these signs were reported to be signifi-  cant indicators of IDN risk in the reviewed articles:  interruption of the radiopaque band of the canal [62, 66, 69,  73-76], canal diversion [59, 74, 76], root darkening [59, 62,  74, 76] and mandibular canal narrowing. [70, 74, 76] In con-  trast, a retrospective study by Pippi et al. [72] found that  none of these signs were significantly associated with nerve  injury, even when two or more were observed. CBCT radio-  logical signs have also been associated with IDN damage.  Detection of contact between lower third molar and man-  dibular canal has been found to potentially influence the  resulting nerve damage, [62, 68, 69, 72, 77] which is associ-  ated by Kim et al. [70] with a 21-fold higher risk of paraes-  thesia. Various studies [67, 69, 73, 78, 79] have associated  nerve injury with the lingual position of the mandibular canal  with respect to the third molar root, attributed to the more  likely interruption of the mandibular canal cortex due to the  direction of extraction manoeuvres. The RCT reported by  Ghaeminia et al. [ 62] found the risk of nerve injury to be  16-fold higher when the localization was lingual versus buc-  cal. In addition, some authors have described a higher risk of  IDN injury for dumbbell-shaped versus round-, oval- or  drop-shaped canals [72, 73, 76, 77].   There are seven radiological signs identifiable by pan-  oramic radiography, which indicate a close relation-  ship between lower third molar and IDN: root  narrowing, root darkening, apex darkening and bifid  images, changes in root direction, dental canal narrow-  ing, dental canal diversion and interruption of the  white line of the dental canal.    Two studies related the type of anaesthesia to IDN injury.  Nyugen et al. [67] found a significantly higher (p = 0.007)  frequency of permanent damage in lower third molar surgery  under general versus local anaesthesia, and Costantinides  et al. [80] reported a 2—16-fold greater risk of IDN injury  under the former. One explanation is that the absence of  patient feedback with general anaesthesia means that sur-  geons are less aware of the force applied. Hasegawa et al.  [69] observed a significantly higher (p < 0.05) IDN injury  rate in patients with versus without nerve exposure during  the surgery. However, Pippi et al. [72] reported nerve injuries  in only 6.5% of cases in which the nerve was exposed versus    9.3% of cases in which it was not, suggesting that IDN expo-  sure may simply reflect the close proximity of tooth and  nerve and cannot per se be considered an indicator of poten-  tial nerve damage. Three studies associated haemorrhage  during third molar extraction with IDN injury [62, 75, 81],  without elucidating whether the bleeding resulted from man-  dibular canal fracture or a haematoma or other causes of  nerve compression.   With respect to the experience of the clinician, Nguyen  et al. [67] found a significantly higher frequency of perma-  nent IDN injury (p = 0.026) amongst inexperienced dentists  in comparison to oral specialists or maxillofacial surgeons,  possibly related to inappropriate force and less instrumental  control in the hands of those with less experience. The same  study also explored the effect of surgery duration, finding a  higher nerve injury rate when this was more than 20 min  (from incision to completed tooth extraction), mainly  because a longer surgical time implies a more challenging  extraction. With regard to the surgical approach, Jain et al.  [73] reported a significantly (p = 0.04) higher nerve injury  rate in patients who underwent odontosection versus those  who did not. This may be explained by the less extensive  ostectomy often associated with this procedure although  odontosection can be a direct risk factor for IDN injury in the  extraction of horizontal third molars [82].    Demographics A prospective study by Charan Babu et al.  [83] reported that older age was a significant risk factor for  LN injury (p < 0.05), but Kjoelle et al. [66] found no differ-  ences in permanent nerve damage amongst age groups. No  significant gender differences in LN injury rate were found  in any study.    Anatomical Charan Babu et al. [ 83] observed a significantly  (p < 0.01) higher risk of LN injury with greater impaction  depth, attributed to the more difficult extraction and, there-  fore, more extensive osteotomy. A higher LN injury rate was  observed for distoangular impactions [67, 83] generally due  to the more difficult extraction and for horizontal extractions  [83], possibly because of the larger amount of bone removed.  However, these associations were not statistically  significant.    Surgical Charan Babu et al. [ 83], Osunde et al. [84]  and Yadav et al. [85] reported a significantly higher LN  injury rate (p < 0.01, p < 0.001 and p < 0.001, respec-  tively) in patients who had undergone lingual flap    retraction before third molar extraction than in those  who had not.    This injury was found to be transient in the RCT by Shad  et al. [86], who suggested that permanent injury can be pro-  duced when the lingual flap is not separated from the bone.  Three studies [62, 85, 87] observed a significant association  between higher LN injury risk and the requirement for odon-  tosection in third molar surgery.    Various authors have proposed alternative surgical tech-  niques to avoid nerve damage in lower third molar extrac-  tion, but their findings should be considered with caution  due to major study limitations (e.g. no control group and  small sample size), and there has been little research on this  issue. In a study of 53 patients, Bataineh et al. [88] reported  a modified flap that appeared to reduce LN lesions caused  by flap retraction, considering all known anatomical varia-  tions of LN. Ge et al. [89] observed lower nerve injury rates  when type III lower third molars in lingual position were  extracted by piezosurgery in a lingual split approach in  comparison to published rates reported using the conven-  tional lingual split technique. The persistence in defending  lingual access third molar surgery is inappropriate, in that it  significantly increases the risk of temporary lingual nerve  injury and 10-12% of these injuries will be permanent [90].  A recent literature review recommends avoidance of lin-  gual flaps in third molar surgery to minimize lingual nerve  injury [91].   A recent surgical technique to mitigate the risk of high risk  third molars in close proximity to the IDC is a coronectomy.  Coronectomy, in which the dental crown is removed and the  root is retained in the jaw, has been recommended to reduce  IDN injury risk in cases of close proximity between nerve and  third molar, and the majority of the reviewed studies described  any IDN injury with the utilization of this approach [60].  Nevertheless, this technique is not free of controversy, even  when clearly indicated, given the possibility of infectious  complications around the root or its migration [92-95].  Extraction by orthodontic traction may also be useful when  there is a high risk of nerve injury, and Wang et al. [96] found  no cases of nerve injury in patients undergoing this procedure  although account should be taken of study design limitations  and the small sample size. There is a strong evidence base to  support the prevention of IDN nerve injuries using the coro-  nectomy technique [43, 44, 53, 54, 97].    Lingual nerve injury  Increased patient age  Increased duration surgery  Lingual access surgery  Inexperience of surgeon  Distoangulation of third molar  Depth of impaction   Inferior alveolar nerve injury  Proximity of tooth root to inferior dental canal  Increased patient age  Increased duration surgery  Inexperience of surgeon  Distoangulation of third molar  Depth of impaction    Summary prevention of third molar surgery-related nerve  injury (Table 25.3) [98, 99].    ¢ Nerve injury risk does not appear to be influenced by the  diagnostic imaging technique used (CBCT or panoramic  radiograph) although the utilization of CBCT may possi-  bly reduce the risk of transient injuries. Studies with  larger sample sizes are needed to clarify this issue.   e Older age, female sex, mesioangular position, impaction  depth, utilization of general versus local anaesthesia,  haemorrhage, inexperience of the clinician and certain  signs on panoramic radiography and CBCT appear to be  associated with a higher risk of IDN injury.   e Lingual flap retraction, older age, horizontal and distoan-  gular positions, impaction depth and odontosection may  be possible risk factors for LN injury.   ¢ Coronectomy is evidence based to prevent IDN injuries in  selected cases, High-risk third molar, healthy and coop-  erative patients and vital tooth.   e Definitive conclusions are limited by the variability in  study design (with the inclusion of some retrospective  studies), reduced sample sizes and differences in the  experience of clinicians, amongst other factors. However,  buccal approach technique (when undertaken properly)  will minimize lingual nerve injury.    It is not possible to classify the degree or outcome of a sen-  sory nerve injury based on patients’ presentation early post-  injury. Just as with phantom limb pain patients, who may  express non-existence or existence of a ‘normal feeling’ limb  (after amputation, the most catastrophic nerve injury) with or  without pain, numbness or altered sensation, these symp-  toms do not reflect the degree of injury or prognosis. Thus, in  order to assess the end results of nerve injury, the patient  must be reassessed and/or treated if indicated. The type and    Procedure Recovery rate  Third molar surgery [7] IANI - 67%; LNI — 72% Buccal  access TMS  LIN — Lingual access TMS 88%  Mandibular fractures [7] IANI- 91%  Orthognathic surgery IANI - 87%   (BSSO) IANI (patients 80-92%)  Local anaesthesia inferior dental 75%  block (mainly Lidocaine) [14]  Implant-related [ANI [87] Complete recovery — 50%  Partial recovery — 44%    A review of common operations such as groin hernia repair, breast and  thoracic surgery, leg amputation and coronary artery bypass surgery  found an incidence of chronic post-surgical pain in 10-50% of patients  [100].   Summary of type and timing of management (Table 25.5  and Fig. 25.2) Management of third molar-related nerve  injuries will depend upon the presentation of the patient  (pain, functional and psychological implications) duration  and cause of the nerve injury [56, 98]. Figure 25.2 summa-  rizes the management and timing of intervention for trigemi-  nal nerve injuries based upon the current evidence base [56,  98]. It is recognized that neuropathic pain does not respond  to surgical intervention, and thus, prevention and early man-  agement are paramount in preventing chronic life-long pain  after routine surgery in these patients. Advice is summarized  on the Trigeminalnerve.org.uk website.    High risk nerve injury/ or patient  high risk of developing neuropathic  pain consider pre-emptive    neat . permitting)  Amitriptyline or Pregabalin e step down Prednisolone 50-10mg over 5 days e Step 1 Amitriptyline or Nortriptyline  (exclude known risk of DU and or PU) e Adjunctive topical agents (Lidocaine, Capsaicin)  e Vitamin B complex (long term during recovery) e Step Il Gabapentin or Pregabalin  e Review    If required: Psychological support (for PTSD and sleep disorders)  and Therapeutic management of neuropathic pain (NICE  Guidance Ne Pain in adults)    Inferior alveolar nerve DPT confirms  retained roots or bony defect of IDC    Consider early exploration (IAN via  M3M socket) +/- nerve repair  dependent upon surgical findings    Patient presents with  persistent non-  resolving LINGUAL  nerve injury after  lingual access(lingual  retraction +/- lingual  split) surgery    Patient presents with  persistent non-resolving  Inferior alveolar nerve  injury OR LINGUAL nerve  injury after M3M surgery    e MARI micro neurography may assist in confirmation of damage to IAN and LN (currently available in US under development Londan)  e Larger IAN defects can be optimally repaired using Axogen cadaveric nerve graft (currently NICE approved for hand surgery in UK)    Fig. 25.2 suggested management of nerve injuries related to mandibular third molar surgery    The patient with the nerve injury must be treated, NOT  the nerve injury in isolation. The neuropathy, pain, numbness  or pareasthesia, with associated functional and psychologi-  cal impact, will be the driving force behind the patient seek-  ing treatment [98]. These factors must be assessed, and the  potential outcomes, good or bad, should be discussed and  agreed with the patient [99].   Patients sustaining LA, orthognathic, oncology and  trauma-related nerve injuries will mainly be managed thera-  peutically [101-104].   Overall, there is poor evidence to support late surgical  intervention for Trigeminal nerve injuries [6, 105]. Most  studies report on repair procedures undertaken too late, and  early repair is imperative to minimize central irreversible  changes and possibly chronic pain. Generally, surgical repair  of the trigeminal nerves never returns the patient to peropera-  tive neural function; in addition, there is a risk of making a  numb patient into one with chronic post-surgical pain [100,  106]. As with other post-trauma sensory neuropathies, it is  recognized that immediate repair is optimal; [107, 108] how-    ever, this is rarely applied to dental nerve injuries with the  misconception that we should sit and wait for resolution  (only for 3 months for lingual nerve injuries related to lin-  gual access third molar surgery), resulting in long delays  before surgical intervention [109-111].   Some recent studies have highlighted immediate repair  with cadaveric-treated human nerve graft successful in man-  aging various sized defects in planned resection of nerves  related to benign tumour resection or trauma [112, 113].   Recent reports have also concluded that, similar to other  surgical sites, neuropathic pain does not resolve with sur-  gery, with this being the main driver for surgical repair [114,  115].   Many reports have recommended the use of conduits  (venous, prosthetic), sural nerve grafts and other techniques  without sufficient evidence and many with poor outcomes  including neuropathy and pain from the donor sites! The  future may prove that nerve growth factors, other  growth-promoting chemical and anti-neuropathic pain  agents and specialized conduits may play a role in improving    repair of trigeminal nerve injuries, and the overall conclusion  from reviews in this area is that we have a lot of evidence  base to harness [105, 106, 116]. The singular consensus is  that prevention of these nerve injuries is possible and  optimal.   The timing of intervention and mechanism of injury are  paramount in decision making in the treatment of trigeminal  nerve injuries (summarized in Table 25.5).    1. Counselling is the most useful effective tool for managing  patients with problematic permanent sensory nerve  injuries.   2. Medical intervention is indicated for patients with pain or  discomfort or with anxiety and/or depression in relation  to chronic pain. However, due to the multiple noxious  side effects of chronic pain medication, less than 18% of  patients remain adherent with medication.  ¢ acute (medical),   3. Surgical intervention is indicated for:  ¢ Immediate surgical repair for suspected or known   nerve injury or intended surgical defect after removal  of benign tumour or recent trauma [98].   e Within 2-4 week, exploration if clinical presentation  of persistent neuropathy is paramount and radio-  graphic follow-up is not necessary; however, if there is  CBCT evidence of breech of lingual plate or IDC, con-  sider immediate action-nerve exploration + repair;   — Lingual nerve neuropathy patients with CBCT evi-  dence of damage to lingual plate adjacent to third  molar surgical site.   — Inferior alveolar nerve with retained roots or evidence  of bone inclusions or compression of IDC.   — Non-resolving lingual or inferior dental nerve injuries:  Exploratory surgery for lingual or inferior alveolar  nerve injuries within 3 months post-injury. Surgical  intervention is not effective for neuropathic pain, and  if this is the driving force behind seeking surgery, it  should be reconsidered.   — There are reported exciting results of allografting lin-  gual and inferior alveolar nerve injuries. Using a pre-  prepared human-treated cadaveric allograft, the IDN  and LN can be repaired with minimal tension. This is  undertaken using microscopy and described in several  publications by John Zuniga and Michael Miloro  [109]. This is likely to be the treatment of choice if  repair is indicated and direct re-anastomosis cannot be  undertaken most commonly for the IDN. One of the    main issues regarding nerve repair is the early identifi-  cation of the neuroma related to the patients ‘symp-  toms and the connectivity of the nerve itself, i.e. is the  nerve actually functioning. Recent developments with  Magnetic Resonance Neurography (MRN) have  availed the surgeon to identify the nerve lesion and  neural functionality to facilitate appropriate and earlier  nerve repair intervention [117, 118].    Unfortunately, none of these interventions ‘fix’ the patient,  but the aim is to manage their symptoms as best as possible,  improve function and allow them time to accommodate to  these unfortunate events, which is often not very  satisfactory.   This chapter was intended to acknowledge and share  some key issues around iatrogenic trigeminal nerve injuries  and to provide some key take home messages including:    ¢ Neuropathic pain as well as altered sensation and numb-  ness is what most patients experience with iatrogenic sen-  sory nerve injury. This has a significant and unpleasant  effect on the patient (improve your consent!)   ¢ Owing to the significant problems following nerve injury,  pre-operative strategies for minimizing this risk of nerve  damage need to be considered carefully. Peri-operative  planning, operative execution and post-operative care  need improving to minimize and hopefully abolish these  injuries.   e Several strategies are presented to assist in preventing  nerve injuries.   e There is a need for a consensus and standardization of risk  assessment and management, a holistic approach in man-  aging the pain, related effect on functionality and psycho-  logical implications caused to the patients affected by  iatrogenic nerve injury.    1. Caissie R, Goulet J, Fortin M, Morielle D. Iatrogenic paresthesia  in the third division of the trigeminal nerve: 12 years of clinical  experience. J Can Dent Assoc. 2005;71(3):188—92.   2. Hillerup S. 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Magnetic resonance Neurography of traumatic and nontrau-  matic peripheral TrigeminalNeuropathies. J Oral Maxillofac  Surg 2018  Apr;76(4):725-736. _ https://doi.org/10.1016/j.  joms.2017.11.007. Epub 2017 Nov 16.   Chhabra A, Madhuranthakam AJ, Andreisek G. Magnetic reso-  nance neurography: current perspectives and literature review. Eur  Radiol 2018 Feb;28(2):698—707. https://doi.org/10.1007/s00330-  017-4976-8. Epub 2017 Jul 14.    Open Access _ This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.  org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropri-  ate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.   The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in  a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.   Neuralgia can be defined as paroxysmal, intense intermittent  pain that is usually confined to specific nerve branches of the  head and neck. The trigeminal nerve is responsible for sen-  sory innervation of the scalp, face and mouth, and damage or  disease to this nerve may result in sensory loss and/or pain.  Trigeminal Neuralgia (TN), also referred to as “Tic  Douloureux, is sought to be the most intense and well-  known neuralgias, which displays classical features of  intense sharp, stabbing sensations with or without burning  pain throughout the face. It is considered as one of the most  chronic painful conditions known within the body. The pain,  which is often initiated by just a light touch to an area of  skin, can occur at any time without warning and depending  on the severity of the condition, the frequency of the attacks  can vary.   This severe medical condition affects one or more  branches of the fifth cranial nerve known as the trigeminal  nerve, which is the largest cranial nerve and has both sensory  and motor functions. >85% of cases of trigeminal neuralgia  are of the classic type known as classical trigeminal neural-  gia (CTN), while the remaining cases can be separated to  secondary trigeminal neuralgia (STN). STN is thought to be    Electronic Supplementary Material The online version of this chap-  ter (https://doi.org/10.1007/978-98 1-15-1346-6_26) contains supple-  mentary material, which is available to authorized users.    K. Ganesan   Department of Oral and Maxillofacial Surgery, Southend  University Hospitals NHS Trust, Southend-on-Sea, UK    A. Thomson (1)  Norfolk and Norwich University Hospitals, Norfolk, UK  e-mail: ashathomson1! @nhs.net    © The Association of Oral and Maxillofacial Surgeons of India 2021    initiated by multiple sclerosis or a space-occupying lesion  affecting the trigeminal nerve, whereas the leading cause of  CTN is known to be compression of the trigeminal nerve in  the region of the dorsal root entry zone by a blood vessel.   Investigation of the cause of the neuralgia present and  treatment planning of these symptoms can pose a challenge  for any clinician and the importance of detailed assessment  and history taking of orofacial pain should be highlighted.  Extreme care must be taken to identify the underlying cause  of the symptoms experienced by the patient, who may often  present in distress, as suffering from head and neck neuralgia  can severely affect a patient’s quality of life.   There is no guaranteed cure for the condition of trigemi-  nal neuralgia, but there are several treatment options that  may give symptomatic relief. In this chapter, we will review  the common neuralgias occurring within the oral and maxil-  lofacial region with specific emphasis on trigeminal neural-  gia. We will discuss the historical evolution of treatment  including the medical and surgical modalities with the use of  current literature and newer developments. This highlights  the need for further studies and investigation into the phe-  nomenon of neuralgia to improve patient management and  treatment outcomes.   This chapter will also cover surgical interventions such  as, peripheral neurectomies, which can be done by an Oral  and Maxillofacial Surgeon.    This is the largest cranial nerve with both sensory and motor  components. It provides sensory nerve supply to the face,  the scalp, the nasal cavity and the oral cavity including the  teeth. It carries proprioception from the periodontal liga-  ments of the teeth and masticatory muscles. The trigeminal  nerve provides motor supply to the muscles of mastication,  tensor tympani, tensor veli palatini, mylohyoid and anterior  belly of digastric. Its name is derived from its three main    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1-15-1346-6_26    branches ophthalmic, maxillary and mandibular. This nerve  can be divided into various anatomical segments by its  course from the brain stem, cisternal, Meckel’s cave, gangli-  onic and finally to peripheral divisions (Ophthalmic, maxil-  lary and mandibular). For trigeminal neuralgia,  understanding of the anatomy of cisternal and Meckel’s  cave segments is important.   The trigeminal ganglion is located in the Meckel’s  cave, which is a recess between the two layers of the dura  in the posteromedial portion of the middle cranial fossa.  Any disease process in and around the Meckel’s cave can  develop the symptoms of trigeminal neuralgia. The anat-  omy of the Meckel’s cave is detailed through the use of  Fig. 26.1.   Arachnoid membrane from the posterior cranial fossa  extends into the Meckel’s cave and continues along the  rootlets of the trigeminal nerve to as far as the trigeminal  ganglion [1].    Table 26.1 Branches of the 3 divisions of the trigeminal nerve    V3—Mandibular  1. Nervous Spinosus  2. Motor Branches  3. Anterior Division a. Nerve to Lateral Pterygoid  b. Masseteric nerve  c. Deep Temporal nerve  d. Buccal nerve  a. Auriculotemporal nerve  b. Lingual nerve  c. Inferior Alveolar nerve  i. Nerve to Mylohyoid  ii. Mental nerve    Myelin sheath surrounds the cranial nerves formed by oligo-  dendrocytes in the central nervous system and Schwann cells  in the peripheral nervous system. The main function of the  myelin sheath is to provide mechanical insulation and meta-  bolic support for the axons. This myelin sheath at the transi-  tion zone (TZ), between the central and peripheral nervous  systems is a vulnerable area in the context of neurovascular  compressions. The TZ is more relevant and not always  located in the same position as root entry zone (REZ) [2].   Neurovascular compression at the REZ is found to be a  reason for 80% of the TN but not a consistent finding in all  the TN patients. This neurovascular contact at the REZ is  also found in non-TN patients. A superior cerebellar artery  alone or in association with another vessel is found in 88% as  a source for vascular compression. Other vessels such as  anterior cerebellar artery, the basilar artery and vertebral  artery are also found to be in contact with RTZ [3].    In 1950, the first finding of a connection with multiple scle-  rosis is reported [4]. A comprehensive review of pain in MS  patients identified the prevalence to be TN to be 3.8%,  which is lower than headaches (43%) and neuropathic  extremity pain (26%) [5].   From this review, TN was the first symptom of MS in  9-14% of patients and the mean age of onset ranged from  33 to 51, highlighting younger patients than patients with  TN alone. In addition to this, TN due to MS is often associ-  ated with numbness and paraesthesia [6]. Neuralgic pain,  over a period of time, evolves with atypical features and  involves an increase in the number of divisions of trigemi-  nal distribution. Additionally, 6% became bilateral and lit-  erature shows MS precedes TN, however several studies  showed TN as a first symptom before any other MS symp-  tom [7, 8].   Electrophysiologic testing of MS-related TN patients  showed up to 89% abnormal trigeminal reflexes such as the  blink reflex compared to 3% in idiopathic TN patients. In  MS, plaques result in neural damage causing TN but not as a  result of neurovascular compression however, both can play  a role in the aetiology of TN [9].   In MS, ephaptic nerve conduction is effected due to an  increase in inflammatory activity in the plaques with a high  T-cell activity [10].    Tumours alone are shown to be aetiology in TN from 0.8 to  11.6%, but this increased to 5.7 to 13.4% when aneurysms,  angiomas or vascular malformations are present. Tumours  may cause TN by compression, wrapping around the nerve  root, neurovascular compression and/or neoplastic factor-  related chemical irritation [6].    The involvement of diabetic neuropathy is more common  in the 3rd, 4th and 6th cranial nerves than in the trigemi-  nal nerve. Diabetic patients tend to have more of a neuro-  pathic pain than neuralgic pain, which may present as hot,  burning, electric with a pins and needles sensation, espe-  cially in the peripheral areas such as the hands and legs.  Often, this tends to be bilateral, and may present worse at  night [11].   Hyperglycaemia is known to cause aggravated nerve  damage, and this also applies for the increased risk of devel-  oping TN however, more studies need to be done in order to  validate the underlying pathophysiology between the asso-  ciation of diabetes and TN [12].    Post-herpetic TN after herpes zoster-shingles has been docu-  mented [13] and can present as a burning persistent severe  pain for the patients. The reactivation of the latent herpes  zoster virus from the dorsal root ganglion results in TN  affecting the ophthalmic branch in over 80% of cases. When  antivirals are administered within 72 h from the onset of the  rash, they are known to reduce the duration of the rash, pain  and also the incidence of post-herpetic neuralgia [14-17].    The exact aetiopathogenesis of TN remains unclear. The most  common hypothesis is the “ignition theory,” which is a result  of abnormalities in the afferent neurones of the trigeminal  root or ganglion. Injury to the axons can make them hyperex-  citable and also cause central sensitisation, leading to TN  [18].   Demyelination at the trigeminal REZ where central and  peripheral myelin meets results in generation of ectopic  impulses. This in turn can cause cross-talk between touch  and pain sensations which is thought to decrease the central  pain gating mechanisms. Which, can conversely result in tri-  geminal nerve remyelination. This may explain the sponta-  neous remission in some patients; however, the same cannot  be applied for rapid electrophysiologic recovery and pain  relief after microvascular decompression treatment [6].   The affected (demyelinated) nerves can spontaneously  discharge electric impulses. Touch sensation carrying A-f  fibres aligned near the pain carrying (nociceptive pathway)  A-5 and C fibres in the REZ, leading to ephaptic cross-talk  between the two pathways. This may explain how trivial  touch sensation triggers pain in TN [18].   The trigeminal ganglion itself can show pathological  changes such as hypermyelination [19, 20]. Demyelination  is common in many patients with TN and is caused by a com-  pression by vascular structures, MS, tumours and vascular  malformations.   Compression on the REZ should cause a continuous pain,  but TN patients suffer paroxysmal attacks, which are most  likely to be caused by spontaneous discharges where the  threshold for the repetitive firing has been altered. It is also  notable in TN that such firing occurs not only spontaneously  but also by trivial tactile stimuli. This type of firing behav-  iour is also observed within in dorsal root ganglions [20].   Rappaport and Devor [21] explained that the development  of atypical features of the TN may be due to central sensiti-  zation following a prolonged barrage of nerve impulses and  also from progressive damage to trigeminal afferents, which  become the source of continuous ectopic discharges [20].   Interestingly, literature shows that different treatments of  TN yield similar results in pain control however, the long-    term results show that decompression provides prolonged  pain relief compared to destructive peripheral procedures  [20]. In addition, destructive procedures may cause some  degree of sensory loss along with the same duration of pain  relief [22].    Historically, reviews dating back to 2 AD demonstrates the  existence of TN or a similar condition described by Aretaeus  of Cappadocia, a contemporary of Galen. The same author is  known for the description of migraine, and in the 11th century  [23], an Arab physician Jujani describes a unilateral facial  pain causing spasms and anxiety. He explains that the cause  of the pain is ‘proximity of the artery to the nerve’ [24].   Wells Cathedral, an Anglican cathedral in Wells, Somerset,  England, dedicated to St Andrew the Apostle, contains the  tomb of Bishop Button, who died in 1274. He was canon-  ized, and many pilgrims and toothache sufferers left offer-  ings at the tomb, in commemoration of which the capitals of  the pillars bear carvings of people depicted with facial neu-  ralgia. One is famed as the toothache figure and because of  the surprising rarity of dental caries at that time (confirmed  when the sarcophagus was opened in 1848), Wilfred Harris  pointed out the probable relevance to trigeminal neuralgia  [25].   A first Royal account in relation to TN is by John Locke,  the famous philosopher and physician who wrote a series of  letters to Dr John Mapletoft in 1677 [26] describing TN suf-  fered by Countess of Northumberland, wife of Ambassador  to France.   Nicolas Andre invented the term tic douloureux in 1756 in  a book, Observations pratiques sur les maladies de l’urethre  et surplusiers faits convulsifs [27].   John Fothergill publishes the first account of TN to the  Medical Society in London in 1773 and described TN as a  ‘paroxysmal unilateral facial pain, evoked by eating, speak-  ing or touching, starting and ending abruptly, and associated  the condition with anxiety [23].   Between the eighteenth and nineteenth centuries, Pujol,  Chapman and Tiffany completed the clinical picture and dif-  ferentiated TN from other facial pain conditions. Later,  Oppenheim highlighted the association between TN and MS  [28].   Treatment of TN including microvascular decompres-  sion has been available since 1925 [29]; however, it took  another 50 years to become an accepted neurosurgical  intervention. During 1950 to 60, Gardner and Miklos [30]  promoted neurovascular decompression theory and con-  tinued to modify the technique, but a major shift in this  practice happened after a large clinical series published  by Jannetta [31]. Throughout the last century, ablative  neurosurgical procedures continued to evolve to balance    the best possible outcome between pain control and  adverse effects. The latest in this process is radiosurgery.  And even although surgical practice was continuing to  evolve, medical therapy had little success in the same  period. In 1942, Bergouignan’s discovery of phenytoin  was the first medical intervention in effective control of  pain paroxysms [32]. In 1953, Walter Schindler discov-  ered Carbamazepine and marketing was started in 1962.  Although it was originally used for epilepsy, trials showed  their effectiveness in TN pain control.    Within the maxillofacial region, neuralgias can present in  different severities and can affect patients from any race,  gender and age. Certain conditions may be distinctive to cer-  tain groups of people, but there is no current classification  followed for the diagnosis and management of neuralgic  pain; however, groups do exist in order to distinguish the cat-  egories that they may be separated into.   These pain episodes experienced may last from seconds  up to several minutes and can be described by the patient as  an ‘electric shock’ feeling. This sensation may occur fre-  quently per day (up to hundreds of times) over weeks and  months and then suddenly stop with pain-free periods in  between. It may also present infrequently with periods of  remission, which may possibly last for years [13]. The pain  often occurs unilaterally, does not usually cross the midline  of the face and is often unbearable for the patient. It has been  shown that only 3% of cases are known to be bilateral in  nature [13].    Sex  It has been highlighted that TN affects females more than  males [13].    Age  In patients over 80 years old, males tend to have a higher  incidence (45/100,000) [13, 33-36].   It can be prominent within all age ranges, but most  frequently, TN affects individuals over the age of 50.  Approximately 70% of the patients develop TN after they reach  60 years of age and it is known that the incidence of TN  increases with age, and has been emphasised that this condition  is rare to affect people younger than 40 years old [36, 37]. This  is therefore highly important in suggesting that multiple sclero-  sis may be present in younger patients who suffer from TN  [38].   The pain felt can be precipitated by trigger areas or factors of  light touch on specific areas of the face, and patients often  avoid these actions, which they may feel causes the attacks.   Exposure to cold such as cold wind, breeze on the face  or air conditioning   Eating, chewing or biting into something  Touching or washing certain areas of the face    A systematic review highlighted that the range of TN preva-  lence was 0.03—0.3%, mostly women were affected, and the  affected age range was 37-67 years old. The affliction was  marked by unilateral symptoms, most commonly in the max-  illary and mandibular branches [39].   NICE guideline data and studies [13] indicate that a sur-  vey carried out within general practice in the United  Kingdom, which highlighted that the annual incidence of tri-  geminal neuralgia was 8 per 10,000.   The true prevalence of this condition remains unclear as  there is little data to support the evidence of how common  this condition is [13]. It is evident that even with studies car-  ried out, further research is required to validate the preva-  lence of trigeminal neuralgia due to the complexity of the  condition including diagnosis difficulties and heterogeneity  of the disease characteristics [39].   Accurate diagnosis relies greatly on a detailed history of  symptoms from the patient, with pattern and nature of the  pain highlighting the condition as there is no definitive diag-  nostic test yet available. SOCRATES is a useful assessment  tool (Table 26.2), which is often used to help clinicians in  achieving an accurate pain history.    Can the pain be localized to a specific area?  Sudden or gradual? when—day/night/  spontaneous?    Trigeminal neuralgia may be misdiagnosed for dental  pathology, and so it is important that unnecessary dental  treatment is not carried out without full investigation of the  source of the pain. When patients suffer from the condition,  it often becomes apparent that their quality of life decreases  as they may be unable to carry out their normal daily activi-  ties and suffer from weight loss due to problems in eating,  and as a result the condition may lead to depression and/or  isolation.   On clinical examination, trigeminal reflex testing may be  used to test all three divisions of the nerve and may reveal  loss of sensitivity in the cutaneous region, which may be  related to the affected nerve. This may present as partial  numbness (hypoesthesia) or complete numbness (anaesthe-  sia) and occasionally may present as hyperaesthesia causing  considerable discomfort.   e Pain usually only affects one side of the face at one  time.   ¢ Bouts of pain may last from a few seconds to sey-  eral minutes.   e Spontaneous attacks of pain may occur with or  without triggers.   e As time progresses, the painful attacks may increase  in frequency and intensity.   Trigeminal neuralgia can occur as a result of several causes  such as trauma, tumours, infectious or demyelinating dis-  eases, connective tissue diseases and can also be idiopathic  in nature. This poses a challenge to the clinician when trying  to investigate the cause of the pain. The importance of the  causative factors may highlight the possibility that trigemi-  nal neuralgia can present as the first manifestation of an  underlying systemic disease. This emphasises that careful  and in-depth investigations with detailed history taking are  required in order to appropriately treat this life-affecting  condition. A referral to a specialist in pain management or  neurologist should be considered in severe cases [13, 38].   As trigeminal neuralgia is uspected when a patient has  severe and intense pain in the orofacial region, other reasons  may need to be explored for patients who have physical signs  of motor or sensory problems. Neoplasms, infective condi-  tions such as HIV, multiple sclerosis and even cerebrovascu-  lar disease may cause neuralgic pain, and so it is important to  be aware of the differential diagnosis that could be derived  from neuralgia within the head and neck.   TN is restricted to one or more branches of the trigeminal  nerve distribution with an exception of TN in MS patients,  where one side of the face may be affected. It is sudden in  onset and typically lasts for a few seconds to a maximum of  2 min. Pain can be spontaneous but can also be triggered by  innocuous mechanical stimuli or facial movements. In  between the episodes, patients can remain pain-free and very  rarely, patients suffer continuous pain in TN.    Glossopharyngeal neuralgia (GPN) is a rare uncommon  painful neuralgic condition involving pharyngeal/orofacial  region including the ear, base of the tongue, tonsillar fossa  and submandibular region. It has similar etiopathogenesis to  TN with neurovascular compression and demyelination of  the 9th or the 10th cranial nerves. The prevalence rate is 0.2—  0.7 per 100,000 and accounts for 0.2—1.3% of the orofacial  neuralgias [40].   Clinical history taking is important to differentiate differ-  ent types of neuralgias. GPN clinically presents as a unilat-  eral, severe and paroxysmal pain involving the ear, base of  the tongue, tonsillar fossa and submandibular region. Painful  symptoms are described very similar to TN symptoms such  as, sharp, stabbing or electric shock like pain. Similar to TN,  GPN is triggered by innocuous stimuli/function like swal-  lowing, chewing, talking, coughing and yawning.    According to the criteria put forward by the  International Classification of headache disorders  (ICHD) [41]:    e TN pain should be unilateral with at least three  attacks  e Occurring in one or more divisions of the trigemi-  nal nerve, with no radiation beyond the trigeminal  distribution.  e Pain should have at least three of the following  characteristics  — recurring in paroxysmal attacks lasting from a  fraction of a second to 2 min  — severe intensity  — electric shock-like, shooting, stabbing or sharp in  quality  — precipitated by innocuous stimuli to the affected  side of the face  e There should be no clinically evident neurological  deficit    The International Association for the Study of Pain (ASP) current  classification    Classical Caused by vascular compression of the trigeminal nerve  TN root, resulting in morphological changes of the root  Secondary Caused by major neurological disease, e.g. a tumour of    TN the cerebellopontine angle (TN attributed to space-  occupying lesions) or MS    The readers may access the detailed classification at the fol-  lowing open access publication [42]. https://doi.org/10.1007/  s40265-018-0964-9.   A thorough pain history and a clinical examination including  cranial nerve examinations are important for the diagnosis of  TN due to the fact that MS and tumours may be found in this  cohort. Any deficiency in the cranial nerve examination,  especially a sensory loss, should prompt further imaging.   In order to rule out possible diseases, specific tests may be  carried out in adjunct by radiographic examinations such as  plain radiographs including intra-oral (periapicals) and  orthopantograms. These may be carried out in the first  instance to rule out dental pathology, and orthopantograms  may also be able to detect temporomandibular joint pathol-    ogy. Cranial computed tomography scan (CT) may also be  used in order to identify any changes of the maxillary sinus.   Magnetic resonance imaging (MRJ) is an important inves-  tigation to investigate and to differentiate between patients  suffering from trigeminal neuralgia due to tumours and MS  [18]. It may demonstrate the close and potentially causative  relationship between the trigeminal root and adjacent blood  vessel and can be of specific value to exclude posterior cranial  fossa lesions [38]. TN caused by MS should be ruled out,  specifically in the younger patient, and this may be aided by  MRI. Clinical Knowledge Summaries (CKS). NICE [13]  guidelines recommend MRI assessment specifically for  younger people, patients presenting atypical symptoms, non-  responders to initial therapy or anyone for whom neurosur-  gery is being considered. Even though MRI is commonly  used, from previous studies carried out, the suggestion of its  sensitivity and specificity seems to be variable [43-50]. As a  result, emphasis is placed on the challenge in identifying the  cause of trigeminal neuralgia as a relationship between the  clinical symptoms and radiological findings as this may not  be clear.   In idiopathic forms of trigeminal neuralgia, it is typical  for no cause to be detected with the patient having both nor-  mal neurological and MRI examinations, which can cause  difficulty with treatment planning. MRI finding of an aber-  rant loop of a blood vessel at RTZ is the most common cause,  and this is reported in about 60-90% of the cases described  in neurosurgical/neuroradiological series [51-54].   Meaney et al. have designed a set of specific parameters  to visualise the blood vessels using thin slices to create the  reconstruction of nerve and vessel in any orientation. This is  called magnetic resonance tomographic angiography  (MRTA) [55]. This reconstruction between the vessels and  the nerves allowed us to identify the neurovascular compres-  sion. In comparison to MRTA, MR angiography only pro-  vides image of the blood vessels. Meaney et al. then validated  their findings by comparing the MRTA findings with surgical  findings. In a series of 52 consecutive cases, MRTA findings  were comparable to surgical finding in 50 out of 52 cases. In  four cases, MRTA misclassified veins as arteries; otherwise,  MRITA is a sensitive and specific method in demonstrating  neurovascular compression [44].    It has been highlighted that first line of treatment for trigemi-  nal neuralgia is still pharmacological treatment. The desired    outcome of these patients is to treat the pain experienced,  manage the symptoms and with time preferably, eradicate  these symptoms in order to improve the patient’s quality of  life. Where appropriate, referral to a specialist pain service  and/or neurologist may be necessary with clear information  and given to the patient.   There are several drugs that have been delivered systemi-  cally or topically in the use of treating trigeminal neuralgia,  which include:    Baclofen  Dextromethorphan  Lamotrigine  Gabapentin  Pregabalin  Sumatriptan  Levetiracetam  Eslicarbazepine  Pimozide  Proparacaine  Tizanidine  Tocainide  Topiramate    The most common therapy of choice is Carbamazepine  for pain control [56] and after carrying out a systematic  review of the literature, The American Academy of  Neurology and the European Federation of Neurological  Societies support Carbamazepine (200-1200 mg/day) [57]  as the first-line treatment to be offered due to strong evi-  dence supporting this pharmacological treatment. In addi-  tion to this, another drug of preferred choice is Oxcarbazepine  (600-1800 mg/day) [57], which is known to have better tol-  erability and is also supported by existing guidelines [13,  55].   All the above drugs have been evaluated using RCTs,  whereas other drugs such as capsaicin cream, phenytoin,  clonazepam, gabapentin, oxcarbazepine, mexiletine and tra-  madol have been assessed from case reports and case series.  Studies involving many of these drugs regarding the full ben-  efit and effect on the treatment of trigeminal neuralgia are  limited, and so further evaluation is required [59, 60]. The  response to the drugs mentioned is unique to each patient,  and it is evident that the doses also vary between patients in  order to achieve a beneficial effect to counteract the symp-  toms experienced. It has been highlighted that it may be  helpful for the patient to keep a pain diary in order to record  episodes and help the patient and clinician identify possible  trigger factors and timing of the pain. This may aid treatment  planning and may give patients back a sense of control,  which has been lost due to their condition.   Based on existing evidence, carbamazepine also known with  the trade name ‘Tegretol’ is an anti-convulsant drug used pri-  marily in the treatment of epilepsy [61] and remains the drug  of choice for standard first-line treatment of trigeminal neu-  ralgia in patients over 18 years of age [13, 57, 58]. It is con-  sidered to be of diagnostic help if complete resolution or  reduction of symptoms occurs after its use [38]; however,  carbamazepine must be used prophylactically and continu-  ously for long periods, with tiered dosages prescribed to suit  individual patients in regard to their response. Carbamazepine  should be used with caution, and as it not an analgesic, it is  not appropriate to use this medication during a pain episode  for relief as it will not have an analgesic effect on symptoms.  Patients can often misinterpret what the purpose of the medi-  cation is, and so this in turn highlights the importance of  patient communication. The mechanism of the medication,  the instructions in terms of dosage titration, timing of effects  and the possible adverse side effects associated with its use  should be highlighted. From current guidelines such as—  NICE [13], it has been advised that if no sinister or red flag  symptoms are evident and carbamazepine is not contraindi-  cated for the patient, then, the following dosage guideline  can be offered:    ¢ 100 mg up to twice daily, titrated in increments of 100-  200 mg every 2 weeks until pain has been relieved   ¢ 200 mg three of four times daily (600-800 mg daily) is  seen in the majority of people to be the dosage of choice  sufficient to manage pain   ¢ Once pain is in remission, the dosage should be gradually  reduced to the lowest possible maintenance level or even  discontinued until a further episode occurs.    Frequent side effects have been reported with the use of  carbamazepine drug therapy with specific emphasis on  elderly patients [61-63]. When patients are treated with car-  bamazepine, it is strongly advised that a full blood count and  liver function tests are carried out prior to starting treatment  and then reviewed periodically in order to monitor the pos-  sible effects of the drug. Hyponatraemia, which refers to low  sodium levels, is thought to occur in 20% of patients, and  NICE guidelines [13] suggests that carbamazepine in con-  current use with sertraline can also increase this risk. Serum  levels of the drug are not routinely monitored unless carbam-  azepine toxicity is suspected but within the \ British National  Formulary (BNF), all information is available in regard to  drug interactions, adverse effects and contraindications and  cautions. Within primary care settings, this is the standard  first choice of treatment if the physician is confident with the  diagnosis; otherwise, it is advised to refer the patient to a  secondary care specialist for further investigations and  treatment.    In several studies, the effectiveness of carbamazepine was  demonstrated with specific outcomes found in the reduction  of both intensity and frequency of the painful paroxysms [36,  57, 64-68]. In addition to this, the pharmacological drug of  choice was found to be equally effective on the reduction of  both trigger touch and spontaneous attacks [59, 66]. Due to  the possible side effects from carbamazepine, oxcarbazepine  may often be used as initial treatment due to the decreased  potential drug interactions and possible greater tolerability  acceptance [57, 63, 68].   It is known for its effective role in the management of neuro-  pathic pain especially post-herpetic neuralgia, but there is a  lack of evidence on its role in the management of TN. There  is one randomized-controlled trial showing improvement in  pain control with fewer side effects. This study compared the  use of combination of both gabapentin and ropivacaine  injected to trigger points and gabapentin alone [18].   Baclofen is used to control the symptoms in MS, and there-  fore, it is generally accepted to use in TN patients with MS  [59]. It may well control the symptoms without adding car-  bamazepine. Its side effects including sedation and loss of  muscle tone and abrupt discontinuation may cause seizures  and hallucinations.    26.8.1.4 Lamotrigine  Lamotrigine is used when Carbamazepine is not tolerated  well, or it is used in addition to carbamazepine when it is not  effective on its own. There is not enough evidence to support  the use of lamotrigine from studies carried out with relation  to patients with TN [18].   Due to the known difficulty in treating trigeminal neuralgia,  new therapeutic modalities are being investigated and have  been tried [57]. It has been evident from recent reviews [18]  that the combination of the pharmacological drug gabapentin  with the addition of regular ropivacaine injections into spe-  cific sites, which may be ‘trigger sites,’ has had a positive  outcome on pain control with an improvement in quality of  life.   Botulinum Toxin A (BTX-A) has also been suggested as  an effective treatment of trigeminal neuralgia from a system-  atic review [69] carried out on patients suffering from this  condition. No major adverse events were reported, and it was  concluded that with an approximate 60-80% reduction in  mean pain intensity and frequency, this medical treatment  may be a future recommendation. Cruccu and Truini [42]  were in agreement with these findings who have also  reviewed the literature on possible medical treatments for    Trigeminal Neuralgia. It was highlighted that there is possi-  ble increasing evidence for BTX-A injections as a treatment  option, specifically prior to considering surgical options or  for patients who do not want surgery. In relation to this, it is  emphasised that further evidence is needed with regard to  this treatment option with more investigation and well-  designed studies to take place.   Finally, it has been highlighted that local anaesthesia  injected into the specific trigger area, 8% lidocaine spray and  the use of intravenous infusion of fosphenytoin may be an  option to provide temporary relief for patients suffering from  severe pain [18].    A successful surgical intervention of TN is determined by  elimination of pain. Currently available surgical options are    1. Invasive technique:  (a) Open:  (1) Microvascular decompression  (b) Percutaneous:  (i) Radiofrequency rhizotomy  (ii) Retrogasserian glycerol rhizotomy  (111) Balloon compression of trigeminal nerve  (iv) Stereotactic radiosurgery—Gamma knife  2. Non-invasive technique:  (i) Peripheral neurectomy  Gi) Alcohol injections  (iii) Cryotherapy  (iv) Selective radiofrequency thermocoagulation    26.8.2.1 Microvascular Decompression (MVD)  The original theory was outlined by Dandy in 1925, and vas-  cular decompression of the trigeminal nerve was first  described by Gardner and Miklos in 1959 [70] and was fur-  ther refined by Jannetta et al. in 1967 [71]. Advances in  anaesthesiology, use of operating microscopes and evolving  surgical techniques allowed the MVD as a safer and effective  procedure. MVD further evolved in the next 50 years to  become accepted as one of the best surgical options.  Surgical target is the trigeminal nerve-pons junction. To  reach this target, the posterior cranial fossa needs to be  accessed via suboccipital craniotomy. On entering via crani-  otomy site, cerebrospinal fluid will be aspirated. Further  advancing is done towards the nerve by gently retracting part  of the cerebellum (Fig. 26.3). It is common to find a segment  of superior cerebellar artery compressing on the REZ. Less    commonly, a variation with an anterior inferior cerebellar  artery or the superior petrosal vein can be found as a cause of  the neurovascular compression [72]. Once the vessel is freed  of the REZ, a piece of Teflon is placed to keep the nerve and  the vessel apart (Fig. 26.4).   Utmost care should be taken to avoid any post-operative  hearing loss. This is usually done by monitoring the brain-  stem evoked potential as hearing loss is due to the pressure  on the eight cranial nerve due to retraction. A timely release  of retraction improves this and literature recommends the  removal of a section of the root when there is no vascular  compression or there may be difficulties in mobilizing the  artery. Deliberate Bruising of the nerve in addition to decom-  pression is also recommended [73].   Literature shows that MVD can be done in any age  group. Both Resnick et al. and Roski et al. concluded that  MVD can be done with good outcomes in the paediatric  population [74, 75]. It is also unique that in the paediatric  population, venous compression is more common than  arterial.   The long-term outcome of MVD for TN suggests 87-98%  have immediate pain relief but this is reduced slightly to    Fig. 26.4 Craniotomy access showing a retracted and a cerebellar  artery resting on the nerve. A piece of Teflon to be placed between the  vessel and the nerve    75-80% in a 1-2 year review [76-82]. This proportion of  patients with pain relief further reduced to 58-64% this is  also associated with 4—12% of recurrence.   Several studies showed that the outcome of MVD is bet-  ter with an arterial compression compared to venous [77,  79, 83]. Lee et al. showed a recurrence rate of 31% when  there is TN due to venous compression and mostly recurred  within the first 12 months [83]. Literature shows that there  are poor outcomes on patients who have had previous neu-  rosablative surgery, but this is not substantiated by other  studies [76, 84, 85]. Review of literature in the manage-  ment of recurrence following MVD in TN did not provide a  general consensus but suggested re-exploration and neu-  roablative procedures [86-88]. A good quality imaging sys-  tem may enable the surgeon to pinpoint the reason for the  recurrence and choose an appropriate remedial surgical  intervention.   In terms of the outcomes, complication rates seem to be  minimal with an experienced neurosurgical team with inno-  vations. Although a rate of 0.2—1% mortality is shown in the  earlier literature, two large studies with a patient population  of 444 [79] and 1995 [52] showed 0% mortality. A recent  retrospective study listed other complications such as cere-  bellar injury (0.45%) 8th cranial nerve injury (0.8%) and  CSF leak (1.85%) [52].   Although this study showed low complication rates, other  centres reported higher complication rates [80, 81]. This  wide range in the outcomes is likely due to the experience of  the surgical team and their advanced perioperative monitor-  ing systems.    Despite the increasing popularity of MVD, its advantage  over the neuroablative procedures continues to be debated at  various levels [22, 89]. In the absence of well-structured  clinical studies, varying interventions will be preferred based  on the individual centre experience.   In the 1950s, the term and the concept of radiosurgery and  Gamma Knife were introduced by Lars Leksell. GKRS is used  to treat various benign and malignant brain tumours and also  various non-neoplastic conditions such as vascular malforma-  tions without an open intracranial surgical access. For the next  few decades, GKRS is evolved with technology as the preci-  sion targeting has improved [90]. The ‘Gamma Knife’ tech-  nique was based on the fact that radiation may block the  conduction of excessive sensory information responsible for  triggering the pain episodes [91]. This would affect the radio-  surgery targets with no significant change outside the target  nerve, with the myelin sheath being primarily affected by  radiosurgery [92]. It is indicated in typical or atypical TN, with  or without vascular compression, failed MVD, TN patients in  MS and patients with significant medical comorbidities.   This procedure [90-92] is done under local anaesthetic  with or without sedation. Once the patient is supine under the  collimator head, local anaesthetic is used to secure the ste-  reotactic frame to the patient’s head. MRI is then performed  to locate the trigeminal nerve. Gamma knife is made up of  201 intercepting beams of gamma radiation with a dose of  70-100 Gy, and it is targeted at REZ of trigeminal nerve.  Radiosurgery can be done with or without frame-based  method, with MRI or computerized tomography (CT) plan-  ning when there is contraindication to MRI.   GKRS can also be given using one or two isocenters/tar-  get areas and targeting radiosurgery posteriorly at dorsal  REZ or anteriorly in retrogasserian zone. Lower dosages to  the root can be associated with fewer side effects, whereas  higher dosages provide better pain control with less risk of  recurrence but more side effects such as facial numbness.  The benefits and risks of a higher dose must be carefully  discussed with patients since bothersome facial numbness  may be an acceptable option for patients with severe pain.   Two studies showed that approximately it takes a month  for pain relief [91]. One of them is a multicentre study of 50  patients with a median follow-up of 18 months, which  showed the results of 58% pain free and 36% had significant  pain relief with a 6% failure rate.   However, when recurrence is evident after GKRS, repeat  GKRS provides a similar rate of pain relief as the first proce-  dure. The best responses are observed when there is good  pain control after first procedure, with new sensory dysfunc-  tion and in single division nerve distribution typical TN.   PBC was described by Mullen in 1980 [93]. It relieves TN  pain by injuring the large myelinated fibres involved in the  sensory trigger. It is especially useful in managing TN with  first division involvement as it selectively spares small  myelinated fibres, which mediate the corneal/blink reflex. It  gained its role in management of TN due to its low cost and  simplicity.   The procedure is performed under a short general  anaesthetic, with a fluoroscopic control. A 14-gauge can-  nula is inserted into foramen ovale but does not pass  beyond. A negative cerebrospinal fluid confirms it further.  A catheter advanced through the needle, and balloon  inflated slowly up to a pressure of 1.3-1.6 atm. Balloon  can also be inflated with 0.5-1.0 ml of contrast dye until  it occupies Meckel’s cave, and radiographic confirmation  of its position is achieved. Up to 6 min of duration of  compression is achieved. Typically, patients awaken with  a mild subjective sensory loss with immediate pain relief  up to 80-90% [94, 95]. This subjective numbness resolves  in few weeks.   PBC is most helpful when pain involves multiple divi-  sions including the first division, patients with MS, signifi-  cant comorbidities and failed MVD.   The procedure is carried out under a short-intermittent  general anaesthesia either under fluoroscopic control or  radiologically guided. Patients are awake for the part of the  procedure to ensure correct positioning of the needle. The  radiofrequency needle with a stylet is introduced through the  foramen ovale into Meckel’s cave using bony landmarks.  Transient bradycardia may occur at this juncture. Once the  needle position at the trigeminal rootlet is confirmed by fluo-  roscopy and radiographs, the stylet can be removed to intro-  duce the electrocoagulation needle. The patient is awakened,  and the stimulation of the nerve root can be tested. A map-  ping of the paraesthesia is carried out to the trigger zones of  the neuralgia. Then, the patient is anaesthetized again for  thermocoagulation, which is achieved with 0.2-1 V. The  same procedure is repeated for 45—90s cycles at tempera-  tures of 60-90 °C. After each episode of thermocoagulation,  the patient is awakened and the sensory mapping is repeated  again [19].   This procedure was a chance finding by Hakansson and  colleagues whilst working on stereotactic gamma radiation  for TN. They used glycerol mixed with tantalum dust as a  radio-opaque marker to visualize the trigeminal cistern and  discovered that it also abolished pain. They published the  first series of 75 patients with a mean follow-up of  18 months [98].   This procedure is done under local anaesthesia with seda-  tion. Similar to other percutaneous in the treatment of TN, the  aim is to safely place the needle at the gasserian ganglion  [99]. The advantage of being done awake allows the patient to  sit up, and a small dose of sterile glycerol is injected in small  increments. Up to a total of 0.1—0.4 ml can be used based on  the number of divisions involved. Patients remain seated for  up to 2 h to allow glycerol to reach the intended root.   This method is well tolerated with negligible mortality.  Commonly reported complications are meningitis, cranial  nerve palsies, local haematomas, reactivation of herpes labi-  alis and permanent masseter weakness [100].    Peripheral neurectomies are a safe and cost-effective option  for patients with medical co-morbidities, elderly and for  population where there is lack of highly skilled neurosurgi-  cal centres. Pain relief can be lasting from 15 to 24 months.  Loss of sensation and recurrences are associated with periph-  eral neurectomy. These are carried out by oral and maxillofa-  cial surgeons, and it is under reported to evaluate its benefits  over central neurosurgical interventions.   Access to infraorbital nerve is gained through a maxillary  vestibular approach. The infraorbital foramen is identified as  it is exiting foramen and the nerve is released from the fora-  men by raising the periosteum around it. Care should be  taken as to ensure that there is no ‘pull’ to trunk of the nerve  from the infraorbital canal. Reeling of the nerve is also a  common practice, but sectioning of the nerve is done to elim-  inate the touch sensation, and there is no need to remove the  infraorbital canal portion of the nerve.   The nerve is then sectioned using diathermy to have a  bloodless field and nerve branches on the soft tissue side may  be closed over by releasing the surrounding periosteum to  avoid regeneration. Similarly, infraorbital canal can be obtu-  rated with bone wax or chips of the bone carved around the  canal.   Khanna and Galinde [101] published their successful  experience of 118 patients with 75% pain relief at a 1-5 year  follow-up.    Oturi et al. published their 7 years follow-up series com-  paring alcohol block, neurectomy and thermocoagulation.  They have found that up to 78% had recurrence with the neu-  rectomy cohort, and sadly, one of half of it recurred within a  month. They reported the complications rate under 10%  (dysesthesia and eye problems) on thermocoagulation and  alcohol ganglionolysis patients [102].    Ali FM et al. [103] suggest peripheral neurectomy in a rural  set-up where there is a lack of highly trained and equipped  neurosurgical facilities. It is an effective option for elderly  patients and who are reluctant for opting for neurosurgical  intervention.   Ginwala’s Access [103] (Video 26.1)  This procedure is done under local anaesthesia, with access  gained to the medial aspect of the ramus using an inverted  Y-shaped incision. Once the incision is made, the mucoperi-  osteal flap is raised along the anterior aspect of the ramus.  The tendon of the temporalis and the medial pterygoid mus-  cle is raised off the bone for access to the lingula and once the  inferior alveolar nerve is dissected free off the surrounding  tissues, the neurovascular bundle is clamped and cut below  the clamp by electrocoagulation to achieve haemostasis.  Following this, a separate buccal sulcus incision is made to  identify the mental foramen and the end of inferior vascular  bundle is identified and dissected off the surrounding tissues.  The bundle is then clamped and sectioned to avulse the neu-  rovascular bundle from the canal.   Based on the available literature, there is a role for periph-  eral neurectomy in selective cases where other treatments  have failed, and in patients with comorbidities and where  there is reluctancy of either clinician or the patient to opt for  neurosurgical procedures. However, it is difficult to conclude  its role as a primary interventional procedure.    Peripheral procedures in the management of TN result in  permanent sensory loss with the aim of achieving pain free  results, and therefore, alternative forms were sought.  Cryofreezing is performed on the surgically exposed nerve  endings with temperatures of —50 to —70 °C [104]. Literature  shows that this procedure is well tolerated by the patients;  however, the results are sub-optimal. In a study published in  1988, 145 patients underwent 348 sessions of which 56%    had more than one session. The pain-free effect lasted less  than 6 months in one half of patients, and at 12 months, only  27% were pain-free [105]. It is also important to note that  61% of the patients remained on their previous medications.  The treatment it is well tolerated by the patients and were  willing to undergo repeated cryofreezing and the distinct  advantage is that the nerve damage is reversible. It is likely  that adjacent nerve branch reconnecting is the reason for the  recurrence of the pain. Although the sensation is preserved  and nerve injury is reversible, its outcomes fall short of other  peripheral procedures. It is reported that 4% of the patients  developed post-operative infections warranting antibiotic  therapy and about 40% had suffered, some from pain ranging  from burning sensation, pins and needles to symptoms such  as a dull ache [105].   In summary, despite patient outcomes with this procedure  and preserved sensation, there is little evidence to support  this procedure in the role of management of TN where other  surgical procedures are available.    Percutaneous ganglionic ganglionic blocks and peripheral  blocks have been used since the 1930s. Direct deposition of  alcohol into the affected nerve peripheral branch causes  chemical ablation of the nerve. Essentially, alcohol causes  destruction of nerve fibres. It can seep into the adjacent tis-  sues and cause necrosis, resulting in pain and local oedema.  With a high-risk recurrence of pain and with a moderate risk  of developing dysesthesia, its use is restricted only in the  elderly or patients with comorbidities or those who are reluc-  tant to undergo extensive neurosurgical procedures.   An injection of 0.5—1.0 ml of absolute alcohol is injected  directly into the affected nerve bundle under local anaesthe-  sia and injections have to be placed accurately to avoid dis-  sipation, which may result in local damage. Utmost care  must be taken to avoid intravascular injections and not to  inject into the subcutaneous tissues [106].   The duration of pain relief varies from 6 to 24 months,  and there is variation with different peripheral branches.  Only a short pain relief with third division is observed com-  pared to the second with a longer duration of pain relief with  in the first division [106].    Other peripheral neurolysis procedures seen in the literature  are radiofrequency coagulation and chemical neurolysis with  glycerol, phenol, mixture of lignocaine with streptomycin  and high concentration of tetracaine. Evidence in the litera-    TN is the most severe type of pain humans ever face for an  innocuous touch without any force, and it is debilitating to an  extent that it was described historically as “suicide disease”  until the development of the medications and various surgi-  cal procedures in the 1950s.   As an OMF surgeon, obtaining a good clinical history is  to rule out other potential pathologys including dental  focus. Patients may be initially present to a primary care  dentist or a physician with facial pain, and they should be  aware of the medical management and the secondary care  team (oral medicine specialists, OMFS and neurologists)  involved to deliver the appropriate course of action. 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Open Access This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.  org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropri-  ate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.   The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in  a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.    1. Definition and classification of the Cysts of the Oro-  maxillofacial region.   3. Pathogenesis, clinical features, radiological picture, his-  topathology, and surgical management of common cystic  lesions.   A cyst is essentially an enclosed sac formed by the cluster of  cells, which group together. The unique characteristic of a  cyst is that the cells that form the outer covering of the sac  are abnormal from the surrounding normal cells of that spe-  cific region. There are various categories of cysts, which can  occur almost anywhere within the human body’s hard and  soft tissues, and their occurrences are very common. They  vary in size from tiny microscopic to huge macroscopic vari-  eties, and the large cysts can displace the adjoining normal  anatomical structures.   Once formed, sometimes, a cyst may resolve on its own,  but in most cases, it keeps growing and needs surgical inter-  vention depending on its type and location. Cysts are usually  nonaggressive, but certain groups of cysts show aggressive  behavior. The cysts of the oral and maxillofacial region are  the commonest pathological entities. Historically, mummi-  fied specimens in Egypt (400 BC to 2800 BC) showed the  presence of cysts [1].    Electronic Supplementary Material The online version of this chap-  ter (https://doi.org/10.1007/978-98 1-15-1346-6_27) contains supple-  mentary material, which is available to authorized users.    N. Malik (4)  Department of Oral and Maxillofacial Surgery, Krishna Institute of  Medical Sciences “Deemed to be University”, Karad, Maharashtra,  India    © The Association of Oral and Maxillofacial Surgeons of India 2021    A cyst is explicitly defined as “A pathological (uni- or multi-  locular) sac that may or may not be lined by an epithelium  and filled with a fluid, semifluid, or gaseous contents and not  created by the accumulation of pus” [1, 2].    Cysts can be found in the facial bones as well as in the soft  tissues of the orofacial region.   Cysts lined by an epithelium are more common in both  jawbones than any other regions of the body because of great  many epithelial cell rests present in close proximity to the  developing jaw bones, and they are called True Cysts, e.g.,  radicular cyst, dentigerous cysts, etc.   Pseudocysts do not have an epithelial lining, e.g., solitary  bone cysts, Cysts of maxillary antrum, etc. [1] (Fig. 27.1).   A cyst is a tissue-space occupying lesion/sac with a cavity  in the center known as a Lumen. There is an outer fibrous  connective tissue wall that separates the cyst from surround-  ing normal tissues. On the inner aspect of this wall, there is a  cystic lining of epithelium, mostly made up of stratified  squamous epithelium (Fig. 27.2). In some cases, there can be  lining other than squamous epithelium.    The etiopathogenesis of orofacial cysts basically originates  from the remnants of the complex processes of embryonic  tissue responsible for jaw and dental development. Such a  conversion does not occur in any other part of the body.   All True Cysts have their genesis from the epithelial rem-  nants along with strong proliferative impetus and capability  for bone remodeling. Odontogenic cysts are derived from    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1-15-1346-6_27    Fig. 27.1 Histological picture of a true (a) and pseudocyst (b)    » Son! Connective Tissue Fibrous Wall-Capsule  ©Association of Oral and Maxillofacial Surgeons of India    remnants of odontogenic epithelium of stomodeum, and  inflammatory cysts are derived from infective process  (Table 27.1).   (1) Cyst Initiation, (2) Cyst Formation, and (3) Cyst  enlargement or expansion    1. Cyst Initiation—unknown stimulus promotes the rapid  increase of epithelial rest cells via cytokine synthesis. The  factors, which are suggested to be responsible for cyst ini-  tiation phase, are mainly genetics, loss of immunological  surveillance, inflammatory mediators, or some local fac-    Table 27.1 Classification of cysts based on the embryological deriva-  tion sources (modified from Regezi et al. [3])    Origin of cell  Type Source rest Cyst variety  Odontogenic Cell rests of | Epithelial Periapical  rests malassez hertwig’s root (radicular) cyst  sheath  Reduced Enamel organ Dentigerous cyst  enamel  epithelium  Rests of Epithelial Glandular  dental lamina connection odontogenic cyst,  (rest of between Lateral  Serres) mucosa and periodontal cyst,  enamel organ Odontogenic  keratocyst, and  Gingival cyst of  newborn & adult  Nonodontogenic Remnants of Paired Nasopalatine  Rests nasopalatine nasopalatine canal cyst and  duct duct-vestigial Fissural cysts  Remnants of Cysts of the  maxillary maxillary sinus  sinus  epithelium   The residual epithelial cells (Table 27.1) are impli-  cated to initiate the process of cyst formation. Initiation is  followed by the rapid growth of the epithelial cells and  the development of a cystic lesion.    After initiation, proliferating epithelial cells form a mass  inside the sac and the innermost central cells become  deprived of nutrients/blood supply, as they are far from  the source of nutrients. The innermost cells do not get  adequate blood supply, and so there is an ischemic  liquefactive necrosis in the center, leading to a cavity for-    mation, which is surrounded by growing epithelial cells.  Enhancement in intercellular edema and acid phospha-  tase activity leads to the formation of microcysts, which  slowly start to form a larger cyst [4].   3. Cyst enlargement or expansion  Once formed, the cyst continues to enlarge slowly, over  the months.  The process is similar for all epithelial lined cysts with  some variations. Many debatable hypotheses have been  put forward regarding the definitive mechanism of cyst  enlargement.   Due to Proliferation or rapid increase in the number of  cells and by the active division of peripheral lining epithelial  cells, surface area of cystic sac increases and the enlargement  of a cyst at the circumference is noted along with the accu-  mulation of cellular contents [4, 5].   Intraluminal concentration and pressure differences between  the cystic cavity and the peripheral growth surroundings  influence fluid movement into the cyst, bringing about an  increase in size.   Cyst starts expanding and growing in size, with the  increase in intracystic pressure due to the intake of fluids  inside the cyst from the surrounding area. (The center of the  cyst has higher concentration of sodium than the surrounding  serum, and so it tends to absorb water.)   This increase in cyst size process is different from the  true autonomous growth, which is found in tumor cells  [5, 6].   Secondary proliferation of epithelial cells is, thus, a result  of increased volume pressure within the cystic cavity, as a  result of osmosis. An osmotic concentration gradient is cre-  ated as a result of degradation and metabolic by-products,  which are taken up inside the cyst.   Due to the rapid increase in the osmotic gradient, the fluid  from the surrounding region diffuses in the cystic cavity,  increasing internal hydrostatic pressure and thereby resulting  in the expansion of the cyst (Fig. 27.3).    Cyst wall -semipermiable membrane  @©Association of Oral and Maxillofacial Surgeons of India    27.4.1.3 Bone Resorbing Factor  In intraosseous cysts, resorption of the surrounding bone  also increases the size of bony cavity.   Newer research points to the role of molecular biology in cyst  proliferation, over older theories of bone loss resulting from  osmotic gradient. The cystic capsule produces bone resorbing  factors like prostaglandins, leukotrienes, and osteoclasts.    (A) Bone degeneration in the jaw bone is brought by  Collagenase (breakdown of collagen), providing room  for cysts to develop. Body’s immune mechanism  releases cytokines and growth factors due to the connec-  tive tissue breakdown, which contributes to the mobili-  zation and proliferation of epithelial cells in the area.  Evidence-based studies showed that collagenase  activities in cystic capsule result in bone degeneration  by destruction of the collagen [6, 7].  Prostaglandin theory—Bone resorption caused by  metabolism of acidic matter produced in the cysts lends  to the cystic growth. These are the substances produced  by the cyst itself, which include Prostaglandin-2 and  Interleukin-1. Along with the epithelial cell division, the  cyst enlarges within the jaw bone due to bone resorption    caused by Prostaglandin-induced osteoclastic activity.  Bone resorption is mediated as a result of production of  PGE-2 and PGE-3 by dental cysts. Prostaglandin-2 and  other by-products are part of arachidonic acid metabo-  lism [8].    The production of prostaglandin-2 can be triggered by  Interleukin-1. Meghji et al. [9] summarized that odontogenic  cysts produce interleukin-1, which in turn triggers the produc-  tion of Prostaglandin-2, resulting in osteoclastic bone resorption  and cyst enlargement. Most dental cysts demonstrate a common  growth mechanism though radicular and developmental cysts  may be initiated by different factors (Flow Chart 27.1).    Many researchers including WHO have tried to put forward  a uniform, globally accepted nomenclatures and classifica-  tions for the cysts of orofacial region. But still there is a con-  tinuous debate going on, and therefore, various classifications  are cited in the literature. WHO in 1992 [2] had classified  cysts into two main categories as odontogenic and nonodon-  togenic, with further subsets as developmental and inflam-  matory (Flow Charts 27.2 and 27.3).    IL, Cysts of the jaws  IL. Cysts associated with the maxillary antrum  TM Cysts of the soft tissues of the mouth, face, and neck.    This simple classification did not include Calcifying  odontogenic cyst (COC), cysts involving maxillary sinus  and nonodontogenic soft tissue cysts. WHO in 2005 [10]  reclassified the cysts into epithelial and nonepithelial  varieties, which were further divided into odontogenic  and nonodontogenic types. At this time, COC—calcify-  ing odontogenic cyst—and Odontogenic Keratocysts  (OKCs) were not considered as cystic entities, but they  were listed as _ keratocystic odontogenic tumors—  KCOT—and calcifying cystic odontogenic tumors—  CCOT—tespectively. The justification for this new OKC  designation was the high recurrence rate and aggressive  behavior along with association with mutations in PTCH  gene. This reclassification led to a lot of confusion, and it  was not accepted by many. But in 2017, the peer group of  WHO did not think that there was sufficient affirmation  for classifying both OKC and COC as neoplasms.  Therefore, in 2017 again, both these lesions were put  back in the cyst category [11].   Among so many classifications, Shear (2007) has sug-  gested a comprehensive classification of cysts with good  understanding of cystic lesions of mouth, face, and neck  region [1] (Table 27.2).    The cysts of the jaws are divided into those that are:    I. Cysts of the jaws  A. Epithelial-lined cysts  1. Developmental origin  (a) Odontogenic Developmental cysts  (i) Odontogenic keratocyst  (ii) Dentigerous cyst  (iii) Developmental lateral periodontal cyst  (iv) Gingival cyst of infants  (v) Eruption cyst  (vi) Gingival cyst of adults  (vii) Glandular odontogenic cyst  (viii) Calcifying odontogenic cyst  (ix) Botryoid odontogenic cyst  (b) Nonodontogenic Developmental cysts  (i) Midpalatalraphé cyst of infants  (ii) Nasolabial cyst  (iii) Nasopalatine duct cyst  2. Odontogenic Inflammatory origin  (i) Radicular cyst, apical, and lateral  (ii) Paradental cyst and juvenile paradental cyst  (iii) Residual cyst  (iv) Inflammatory collateral cyst  B. Nonepithelial-lined pseudocysts  (i) Solitary bone cyst  (ii) Aneurysmal bone cyst  II. Cysts associated with the maxillary antrum  (i) Retention cyst  (ii) Mucocele    Ill. Cysts of the soft tissues of the mouth, face, and neck  (i) Dermoid and epidermoid cysts  (ii) Thyroglossal duct cyst  (iii) Lymphoepithelial (branchial) cyst  (iv) Anterior median lingual cyst (intralingual cyst of  foregut origin)  (v) Nasopharyngeal cyst  (vi) Oral cysts with gastric or intestinal epithelium  (oral alimentary tract cyst)  (vii) Cystic hygroma  (viii) Thymic cyst    Quite a large number of studies are conducted on jaw cysts,  but detailed information on demographic profiles in different  populations is limited and most have focused on odontogenic  cysts [12, 13] (Box 27.1 and Fig. 27.4).    Box 27.2 Diagnosis of the Cystic Lesion Can Be Arrived  by the Following Steps   B. Clinical Examination (signs and symptoms, site,  inspection, palpation, percussion, teeth vitality  check, and aspiration of the cystic content)    History: Duration of the complaints/progress is also  important. History of pain, loose teeth, occlusion  change, intraoral/extraoral swelling/discharge, or sinus    e The jaw cysts are more common than cysts of other  bones in the body [12].   e Prevalence of odontogenic cysts is higher (90%)  than nonodontogenic cysts in the jaws [12, 13]   e The commonest varieties are periapical cyst (65%),  dentigerous cyst (24%), and OKC (5-8%) [12, 13]   e Inflammatory cysts account for 36%, whereas  developmental cysts represent 27% of all cysts. 4%  cysts are either unclassifiable or nonepithelial  (Lucas and WHO classification) [12, 13]    Age: Range from the Ist to 9th decades. Peak inci-  dence is seen between 21 and 30 years of age.   Sex: More prevalent in males, with a male to female  ratio of 1.4:1 [12, 13]   Site: Review of literature suggests mandibular pre-  ponderance and may imply a higher tendency for acti-  vation of cell rests to cystic degeneration in the  mandible.    track, missing teeth, and delayed eruption of teeth  should be noted.    27.7. General Key Attributes Regarding an  Oro-maxillo-Facial Cyst-Signs &  Symptoms (Boxes 27.2 and 27.3)    Signs and symptoms of a cyst depend on its size and site.  Small cysts are detected as an incidental finding during rou-  tine radiographic examination. Large cyst after enlargement  can be noticed first by the patient himself, or there can be  facial disfigurement noticed by others. Generally, cysts are  symptoms free, unless they get infected secondarily.   If the cyst has not enlarged beyond its normal anatomical  boundaries of the jaw bone, then its lump cannot be palpated  intraorally or extraorally. The majority of cysts expand very  slowly, and the surrounding bone gets time to form fresh  subperiosteal new bony layer around the lesion, which iso-  lates the lesion.    1. During early stage, smooth, bony hard, and painless  prominence can be felt.   3. When the cyst grows in volume, the outer cortex is thinned  out, due to the loss of bone mineral content and may show  “Ping Pong/Table Tennis Ball” springy consistency, or   4. Fluctuation can be felt in its center, where the cyst has  eroded the bone and the cystic sac fuses with oral mucosa.  Cysts, which show buccal cortical expansion, are still  mostly covered with a thin layer of the new bone. Cysts  are typically slow growing and tissue space occupying  lesions and have the capacity to displace or replace nor-  mal tissues. They form compressible, fluctuant swelling,  if encroached into the soft tissues, and if they are very  close to the mucosal surface, then bluish tinge is seen. A  majority of cysts show buccal cortical expansion as the  cyst grows in size, but in some aggressive cases, lingual  or both buccal and lingual expansion can be seen, which  produces facial disfigurement.    A cyst may become secondarily infected, and pus dis-  charge may be seen into the oral cavity via a sinus tract.    Examination of the sinus track and discharge from sinus  track should be checked for cholesterol crystals or pus. Salty,  sweet, or unpleasant taste of the discharge is noted.   At this stage, patient may complain of pain. Loosening of  adjacent teeth or displacement of the teeth out of their nor-  mal arch alignment can happen. Very rarely, depending on  the variety of cyst, as it enlarges to an enormous size, it may  resorb adjoining teeth/roots, as well as bone, and may end  up in pathological fracture of the jaw bone. As most cysts  enlarge at a slow pace, and even in the large lesions, the  inferior alveolar canal usually gets displaced and there will  be no altered sensation (anesthesia or paraesthesia).  Paraesthesia and/or anesthesia of the lower lip can exist in  aggressive or acutely infected cysts. Percussion of involved  teeth will produce a dull or hollow sound. Usually, high-  pitched sound is obtained on the uninvolved teeth.  Edentulous patient will complain of ill-fitting denture due to  the bulge. Periapical cysts are always seen in relation to one  or more nonvital teeth. A large maxillary anterior region  cyst may cause distortion of nostril shape and show nasal  congestion. Diagnosis can vary as per the site of the lesion,    Fig. 27.5 Clinical examination: extraoral inspection; (a) extraoral  swelling on the right cheek area, (b) head position for inspection of  swelling and comparison with normal side, and (c) intraoral examina-    age of the patient, clinical, radiological, and histopathologi-  cal examination (Fig. 27.5).    In cysts other than radicular cysts or inflammatory peri-  odontal cyst, there is no compromise in blood supply of  the teeth, and so teeth vitality is preserved. Vital teeth are  associated with odontogenic keratocyst, solitary bone cyst,  lateral periodontal cyst, etc. In inflammatory cysts, the  vitality of all involved and adjoining teeth should be  checked.    Radiographic picture of a cyst is not always pathognomonic.  It will depend not only on cyst category, but also the variants  related to its duration, location, and degree of expansion and  the presence or absence of infection. When the patient is  referred for X-rays, the type of film used will depend on the    tion showing obvious bulge in right buccal vestibule. (Courtesy Dr,  Kumar Nilesh, SDS, Karad)    size of a lesion. Dental panoramic or maxillofacial Cone  Beam CT provides good imaging for most of these cystic  lesions. They help to define site, size, extent, and marginal  outline of the lesion.   Intraoral film: For smaller lesions, minimum of two films  are taken at right angles to one another. Periapical and occlu-  sal views may be taken.   Patient may be referred for CT scan or MRI in cases of  extensive aggressive lesion or recurrent lesions to know the  exact expanse, proximity to the important vital structures/  adjacent anatomical structures, perforations, and multilobu-  lated/multicystic character. If there is suspicious extraosse-  ous lesion with soft tissue extension or malignancy, then it is  also indicated. Postoperative imaging helps to assess the rate  of regression and bone regeneration.   1. Radiographically, intrabony cysts, small or large, form  sharply defined unilocular or multilocular radiolucency  with or without cortication.    Fig. 27.6 Different radiological picture of the cystic lesions as per the  types: (a) replacement type (cyst in place of third molar), (b) envelop-  mental type (cyst enveloping lower third molar), (c) extraneous type   3. The shape of a cyst will vary, depending on the type;  round or oval in radicular or dentigerous cysts, scalloped  margins in odontogenic keratocyst, traumatic bone cyst,  pear-shaped, heart-shaped in nasopalatine or incisive  canal cyst.   4. Cortical expansion, perforations, or pathological frac-  tures may be seen.   5. Displacement or compression may be noticed on the  adjacent dentition, maxillary sinus, or neurovascular  bundle.    (ascending ramus cyst away from teeth), and (d) collateral type (adja-  cent to the roots of the teeth)    The orofacial cyst contains fluid in its cystic cavity, which  varies in consistency, color, and protein content, and helps in  differentiating and arriving at a provisional diagnosis based  on these observations. These findings should be remembered  to be able to diagnose any cyst, which may be encountered in  the clinical practice. An aspiration biopsy of a cyst is the  norm for initial diagnosis of all cysts.    e Aspiration with syringe is always positive for most of the  odontogenic cysts. Aspiration can be carried out after the  clinical examination is over or at the time of planned inci-  sional biopsy. Aspiration and excision biopsy can be done  in the same sitting for small lesions.   ¢ Aspiration of Intralesional fluid is done using a wide bore  needle of 18 gauge and 5 ml syringe under local anesthe-  sia. It is a very valuable provisional diagnostic aid with  simple procedure with least discomfort. Inability to retract  the plunger may be due to a solid mass. Introduce a needle  occlusally, as this area is usually thinner than buccal or  lingual side (Fig. ).    Fig. 27.7 Aspirated cystic fluid; (a) aspiration from infected radicular cyst, (b) aspiration from infected keratocyst    Cystic contents are different ranging from clear yellow  fluid to a creamy or cheese like semisolid liquid. The con-  tent can be examined for its color, consistency and for the  existence shimmering cholesterol clefts or crystals  (microscopic examination of cholesterol crystal shows an  envelope with cut-corner appearance). Electron micro-  scopic examination reveals the presence of various pro-  tein fractions like alpha and beta globulin , albumin, flecks  of keratin, as well as total protein content along with inor-  ganic phosphates [14] (Table 27.3).   Toller has opined that by an active cellular transport mecha-  nism, the proteins are drawn into the cystic fluid by immuno-  globulin (Ig) producing cells. Estimation of IgA, IgG, and IgM  levels in cystic fluid can be done quantitatively [15]. Smith  et al. [16] concluded in their study that the most of the cystic  fluids show the presence of proteins with higher molecular  weight. This is due to the fact that the semipermeable intraepi-  thelial channels facilitate the passage of lactoferrin into the  cystic lumen.   The cystic fluid, which is collected via aspiration biopsy,  can be biochemically analyzed for their protein content esti-  mation by Cellulose acetate membrane (CAM) electrophore-  sis. First, the cystic fluid is transferred to the centrifuge  machine for the removal cell debris and deposits at 2000 rev/  min for 5 min.   Since electrophoresis studies the movement of charged  particles through an electrolyte, which is subjected to an  electric field, and it separates different proteins as per  their physical properties, the fluid free of debris is then  studied qualitatively and quantitatively. The protein mix-  ture is applied to the end of the CAM strip. Scanning of  these impregnated CAM strips can be carried out using a  densitometer for the quantitative estimation of protein  fractions.   Clear fluid  Serous type of  fluid;  sometimes,  blood is  aspirated, or  empty cavity is  found   4 gm/100 ml of Aggregate  Total protein. The  predominant presence of  Albumin is seen, which is less  soluble.    Incisional (for large lesions) or excisional (for small lesions)  biopsy and histopathological examination of the specimen is  the gold standard to arrive at final diagnosis.    With all the investigation results in hand, the surgeon will  have a clear idea of the type, the location, extent, and behav-  ior of the lesion. A final diagnosis is then obtained, and a  suitable surgical line of treatment is decided upon (Boxes  27.4, 27.5, 27.6, 27.7, 27.8, 27.9, and 27.10).    Box 27.4 Clinical Tips  Incisional Biopsy: For large lesions, a “representative”  section of the lesion is incised with the help of a scal-  pel along with the normal tissue and sent for histopath-  ological evaluation. An elliptical, wedge-shaped tissue  is obtained with the “V” of the wedge converging into  the deeper tissues. The depth of the biopsy should be  enough to obtain a representative area of the lesion.  Excisional Biopsy: It is a combination of diagnostic  and curative procedure and is suitably smaller for  lesions <1 cm. In these cases, the entire lesion is  excised in toto at the same sitting and sent for histo-  pathological examination.    e Cysts continue to grow and show a tendency to  increase slowly in size   e Cyst can make the jaw bone weak, leading to patho-  logical fracture   e Few cysts can undergo transformation to aggressive  pathological lesions like ameloblastoma or squa-  mous cell carcinoma   e Cysts prevent eruption of teeth (as in the case of a  dentigerous cyst)   e Cysts can involve neighbouring structures like  teeth, maxillary sinus, nasal cavity, inferior alveolar  nerve, etc.    e Complete elimination of the pathology, minimiz-  ing the recurrence rate & morbidity for the  patient, and improving the quality of life  postsurgically    e Patient’s age & general health and coexistence of  NBCCS-Nevoid Basal Cell Carcinoma Syndrome/  any other syndrome    e Decompression alone-placement of a drainage  tube-palliative (decrease in lesion size)   e Decompression followed by Enucleation along  with adjuvant therapy (two-staged procedure)   e Enucleation Alone with packing, with primary clo-  sure, or with primary closure with bone grafting/  reconstruction   e Enucleation along with excision of overlying oral  mucosa (Stoelinga protocol [18])    Box 27.9 Enucleation with Adjunctive Modalities to  Eliminate the Microscopic Pathologies    e Peripheral ostectomy (Mechanical/physical meth-  ods, Hand instruments like curettes, & use of rotary  bur for removal of perimeter of investing bone)   e Chemical cauterization treatment with Carnoy solu-  tion (1.5 mm depth of bone penetration/5 min)    e Cryotherapy (use of liquid nitrogen after  enucleation)  e Miultidisciplinary Sequential treatment (MST)    Approach (decompression, enucleation, peripheral  ostectomy, and cauterizing bone cavity by carbolic  acid) (Sun et al. [19])    The objective of the choosing any particular surgical method  is to minimize patient morbidity and reduce the recurrence  rate. Surgical procedures for treating cystic lesions are often  put into two categories; conservative or aggressive (Boxes  27.8, 27.9, and 27.10).   Decompression and marsupialisation (cystotomy):  Partsch I operation of the cysts is presumably the earliest treat-  ment. Enucleation or cystectomy with primary closure is also  known as Partsch II procedure (Partsch 1892, 1910) [17].   Decompression, marsupialisation: both methods achieve  evacuation of the cystic contents by creating a surgical open-  ing in the cystic wall. These procedures preserve the continu-  ity of the cystic lesion with the oral/nasal cavity or maxillary  sinus.   Decompression of a cyst is achieved by a minor surgical pro-  cedure, which decreases the intracystic hydrostatic pressure,  which is responsible for cyst expansion. Subsequently,  decompression allows for the bone remodeling and bone fill.    Decompression can be achieved under L.A. by creating a  small opening in the cystic wall and keeping it patent with a  surgical drain. Acrylic tubes, Luer syringes, polyethylene  tubes, nasopharyngeal airways, or nasal cannula or intrave-  nous tubes have been used by fixing them with sutures or  wires to keep the opening in the cyst patent, through which  the cystic lumen is flushed twice/thrice everyday with saline/  antiseptic wash.   Cysts of the lower jaw are normally evacuated through  opening into the oral cavity, and maxillary cysts can be  drained either into the oral cavity, the maxillary sinus or  nasal cavity [17] (Fig. 27.8).   It is a surgical procedure, whereby a cystic sac is modified or  deroofed to convert it into a pouch. This results in a self-  sustaining stoma/opening or outlet, which in turn reduces  intracystic hydrostatic pressure. It is basically a surgical  externalization of the cystic cavity by creating an opening in  the superficial aspect of the cyst. The resected portion is sent  for histopatholgical study. The remainder borders of the cys-  tic wall are then sutured to the surrounding edges of the oral  mucosa, thus converting an enclosed sac, into an open pouch,  exposing the cystic lining or epithelium to the oral environ-  ment. This procedure decreases the volume and size of the  lesion and promotes the speedy healing and new bone forma-  tion. This option is more precise compared to the decompres-  sion method. Marsupialization may be used as a solo  treatment regime for a cyst or as a prior step to final second  stage enucleation [17].    Surgical Procedure Yn Marsupialization, after locally anesthe-  tizing the buccal/labial area, an oval/elliptical incision is taken  to make a surgical window spanning | cm into a cyst; the win-  dow cover consisting of oral mucosa, thinned out bony cortex  and cystic lining, is removed, and the boundaries of the cystic  lining around the surgical opening are sutured to the surround-  ing oral mucosa. In the case of a thick bony cover over a cyst, an  inverted U-shaped incision is planned with a wider base in the  buccal sulcus, mucoperiosteal flap is reflected, and bony win-  dow is removed cautiously with burs or rongeurs. The excised  tissue of the window created must be subjected to histopatho-  logical study. The contents of the cyst are sucked out, and the  residual lining of the cyst is inspected. The remainder cystic  cavity is irrigated thoroughly to lavage any residual debris. The  residual cystic cavity is inspected carefully for any abnormal  findings like ulcerative lesions or possible dysplastic/neoplastic  areas.The cystic cavity is then packed with ribbon gauze strip  soaked with tincture of benzoin or iodoform/white head’s var-  nish or paraffin, or an antibiotic ointment, or bismuth iodine  paraffin paste-BIPP, with its end protruding through the  opening.    Fig. 27.8 Decompression of a cystic lesion by creating a small opening and keeping it patent by inserting a drain. (a, b) Decompression through  oral cavity, (¢) maxillary sinus, (d) nasal cavity    This packed gauze strip is left in situ for 2 weeks, until the  line of junction between the cystic lining and oral mucosa is  healed. After it is removed from the cystic cavity, the patient  needs to irrigate/gargle with antiseptic mouthwash frequently  in a day to prevent food accumulation. The flushing has to be  continued for many following months, until the bone fill and  complete healing is noticed.   Later on, acrylic plate or plug/obturator can be prepared  to protect the healing cavity and used until it gets obliterated  over a period of time, but as the healing progresses, the plug  needs periodic adjustments (Table 27.4).    Usually, once the cystic lesion regresses in size after initial  marsupialization procedure, enucleation is carried out as a  second stage surgery.   The larger or inaccessible cyst is initially marsupialized,  and bony healing in progress is observed. As the cystic cavity  decreases to a relatively small size, then complete surgical  removal is possible by enucleation. The proper time for sec-  ondary enucleation is when bone covers adjoining vital struc-  tures. This protective shield of new bone prevents their injury  during secondary enucleation, also provides adequate strength  to the basal jaw bone, and prevents pathological fracture.   In a cyst associated with developing tooth bud, as soon as  the tooth erupts into the dental arch alignment, there may not  be any residual cystic lining left to enucleate. Decompression  and/or marsupialization with less morbidity and preservation  of adjoining vital structures has a good rate of success over  many other aggressive treatments (Figs. 27.9 and 27.10).    Enucleation or Cystectomy or Partsch IT with and without  adjunct procedures has been validated as the most appropri-  ate surgical modality for almost all cysts of the orofacial  region, with various adjunct procedures as deemed fit for  individual case.   To enucleate is “complete removal or excision in toto  from its envelope without rupture.” With this, no bone, other  than required for surgically accessing the lesion, is removed.   It is the most versatile treatment modality, and many  researchers have said that the surgical enucleation of a cyst in  one piece has been known to reduce the rate of recurrence.   An enucleation procedure is possible because of the pres-  ence of a fibrous connective tissue layer in between the epi-    Table 27.4 Indications, advantages & disadvantages of decompres-  sion & marsupialization   ¢ When apices of  many adjacent  teeth are  involved in  large cyst   ¢ Guided  Assistance for  eruption of  developing  teeth- young  children with  developing  teeth buds or  unerupted teeth   ¢ Possibility of  creating a  pathological  fracture of a jaw  bone   e There is a change  in the nature of  the fragile cystic  lining, which  becomes thick or  converts to  normal mucosa,  and thereby,  secondary  enucleation  becomes easy.   ¢ Needs patient  commitments to  maintain hygiene with  repeated irrigations  and for long follow-up   ¢ Not recommended for  mentally challenged  patients with multiple  cystic lesions.   e Inability to examine  the whole cystic lining  histopathologically is  also a matter of  concern sometimes  and may miss out  mural pathologic  changes    thelial lining of a cyst and cystic cavity bony wall. This layer  acts as a cleavage point for separating the cystic lining from  the jaw bone and makes surgical procedure of enucleation  easy, aS we carry out stripping of periosteal layer from the  jaw bone. The surgical cavity gets filled with the blood clot  and eventually gets organized into bone formation.   The small cysts can be treated with local anesthesia, but  larger cysts need to be treated under general anesthesia.  As per the size and site of the lesion, the mucoperiosteal  flap is designed, following the right surgical principles. If  the bone over the lesion is thinned out, access can be  gained by removal of the cortical bone by rongeurs. But if  the bony cortex overlying the access area is hard and  thick, then the osseous window is created by using rotary  burs.    Fig. 27.9 Diagrammatic representation of Marsupialization proce-  dure; (a) creation of opening on the buccal side of a cyst, (b) suturing  remaining cystic lining to oral mucosa, (c) final suturing to keep the    After complete enucleation procedure is over, the entire  cavity is inspected for proximity of the adjoining vital struc-  tures and for the remnants of the pathological tissues.. In  large extensive cysts, usually the neurovascular bundle is  pushed to one side by the slowly growing lesion, and in these  cases, atraumatic enucleation should be carried out. Irrigation  and cleaning of the entire bony cavity with saline will assist  in visualising/inspecting it. The roughened bony edges of the  cavity are then smoothened with a file or rotary bur before  final suturing.   Cysts that include tooth roots or certain areas of the jaws,  which are surgically inaccessible, require thorough curet-  tage, in order to remove fragile cystic lining fragments. If  devitalization of the teeth is brought about during enucle-  ation, then the affected teeth should be treated with root  canal fillings.    Clinical Tips: If the patient is young and the lesion is  involving multiple anterior teeth, the teeth can be  retained after root canal treatment and apicectomy,  provided thorough inter-radicular curettage by using  small periodontal instruments.   If the teeth show a great degree of mobility and in  the case of recurrent lesion, they should be extracted.    Enucleation of a cyst is followed by watertight suturing  over the sound bone. To achieve this, sometimes, mobiliza-  tion of the soft tissue flaps with advancement is required. If  complete surgical suturing is not possible, then the defect  should be packed with stripped ribbon gauze soaked with an  antibiotic ointment or BIPP/White head’s varnish. Frequent    cystic cavity open into oral cavity, and (d) diagrammatic representation  of Marsupialization procedure    change of this packing is advocated after irrigating the cav-  ity, until new granulation tissue has filled up the cavity and  complete epithelisation of the wound has taken place  (Fig. 27.11).   It is basically used as an additional adjunctive step for  peripheral bone trimming for avoiding resection, as  almost all hypotheses for recurrence point out toward the  possibility of leaving residual pathological fragments  behind, especially, in the large cyst with scalloped bor-  ders or cysts with difficult access. Here, a greater risk of  incomplete excision may exist. Adjunct procedure of  peripheral ostectomy may be carried out in cases of cysts,  which have high recurrence rate, e.g., Odontogenic  Keratocyst. A peripheral ostectomy with rotary bur with  sterile irrigation helps to remove all the microscopic  residual pathological tissue. The procedure is followed to  remove the lesion in one piece along with an enveloping  border of bone, and hence, the possibility of iatrogenic  rupture of the cystic capsule or leaving its fragments  behind is greatly reduced. A minimum 2-5 mm bony  margin inclusion for peripheral ostectomy is supposed to  be adequate. In the case of thin inferior border of man-  dible, reinforcement with reconstruction plate is advo-  cated. This can also be accomplished by means of  mechanical hand instruments like a sharp curette. The  recurrence of the cyst can be prevented by this  procedure.    Fig. 27.10 (CLINICAL CASE SCENARIO): (a) OPG showing the  large radiolucent lesion extending in the mandibular body with impacted  canine at the inferior border, (b) CT scan of the same patient showing  multilocular radiolucent lesion with embedded canine, (c) a large open-  ing was created in the anterior body mandible region, and roof of the  cyst along with oral mucosa was removed along with the evacuation of    the cystic content, (d) healing of the wound after marsupialisation, (e)  acrylic plate was constructed to cover the wound, (f) 6 months follow-  up, lesion reducing in size, and (g) OPG after six months showing the  reduction in size of the cyst. The patient is advised to undergo second  stage surgery for enucleation and extraction of impacted canine.  Courtesy-Prof. Vidya Rattan, PGI, Chandigarh   Many a times, due to the thin, friable wall and the pres-  ence of many small satellite cysts, there is a difficulty of  enucleating it in one piece. Hence, the surgical treatment  is focused on eliminating all residual epithelial frag-  ments. In order to achieve this, a mild, judiciously pene-  trating, and cauterizing agent like Carnoy’s solution is  utilized. It has a mean bone penetration depth of 1.54 mm,  with an application time of 5 minutes. (Carnoy’s solu-  tion’s composition is 3 ml of chloroform, 6 ml of abso-  lute ethanol, | ml of glacial acetic acid, and | g of ferric  chloride) [18, 20-22]. This is adequate to bring about  chemical cauterization of the residual pathologic frag-  ments. Literature shows the use of modified Carnoy’s  solution without chloroform, as it is currently listed as a  carcinogenic agent.    The protocol of carrying out enucleation followed by  the application of Carnoy’s solution in the treatment of  locally aggressive cysts, like OKCs, lowers the recurrence  rate and morbidity. During the application of Carnoy’s  solution, the neurovascular bundle can be protected by  using bone wax cover or wooden spatula or paraffin gauze.   Dashow et al. studied and compared the use of  Carnoy’s solution versus modified carnoy’s solution in  cases of OKCs and stated that the recurrence is almost  eliminated, and the results are comparable to those of the  resection without carrying out the morbid surgery [22].    The aggressive cysts are best treated by enucleation fol-  lowed by cryotherapy, using liquid nitrogen. This therapy  is commonly used for the treatment of many locally  aggressive jaw lesions, such as ameloblastoma, OKC, or  ossifying fibroma [23]. Cryotherapy destroys the residual    Fig. 27.11 (CLINICAL CASE SCENARIO) (a) OPG showing the pres-  ence of a dentigerous cyst in a 7 years old child, (b) clinical intraoral  picture of the same, (c) reflected flap to expose the underlying expanded    epithelial lining cells or satellite cysts and leaves behind  the inorganic bony matrix intact, which is helpful for  osteoconduction. Liquid nitrogen causes bone devitaliza-  tion due to direct effect/damage from ice crystal forma-  tion, which takes place in the cellular and extracellular  compartments and due to the subsequent osmotic and    buccal cortex, and (d) enucleation of the lesion in toto. Courtesy Dr,  Kumar Nilesh, SDS, Karad    electrolyte disturbances [23]. The routine first step in sur-  gery of the lesion is enucleation of a cyst, followed by  cryotherapy. The adjoining tissues are then shielded by  sterile wooden spatula and gauze strip, and the residual  cavity is treated with liquid nitrogen spray—two swipes  for 1 min each, with a 5 min thaw break between two    spray freezes. After cryotherapy, it is possible to place the  bone graft in the cystic cavity to strengthen the jaw bone.  Finally, the wound is sutured in a watertight manner [23]  (Box 27.11 and Table 27.5).    Box 27.11 The Advantages and Disadvantages of Liquid  Nitrogen Cryotherapy After Enucleation  Advantages:    1. The matrix shell of basal bone is left behind, which  acts as a scaffold and induces new bone formation.   . In order to accelerate the bony healing and strength-  ening the jaw bone, immediate bone grafting can be  done. This avoids pathological fracture.    1. Unpredictable results are usually due to utilization  of uncontrolled spray of liquid nitrogen to the area.  This may lead to bone necrosis and postoperative  swelling.   . If liquid nitrogen comes into contact with unpro-  tected inferior alveolar nerve, there will be altered  sensation/paraesthesia or total anaesthesia. In most  of the cases,partial or total recovery of sensation is  expected within 3 months [23].    1. To avoid pathological fracture,  2. To avoid long-term esthetics and functional problems in  larger cystic cavity, more than 4 cm.    Autogenous bone grafts possess characteristic osteo-  conductive and osteoinductive qualities due to the pres-  ence of abundant osteoprogenitor cells. The use of  Autogenous cancellous bone grafts for large defects to  obliterate the cavity and stimulate osteogenesis is the  gold standard, but the issue of donor site morbidity is  always there. The dead space elimination after enucle-  ation of a large defect is recommended by packing the  defect with autogenous bone graft or its synthetic substi-  tute. Calcium phosphates, a- and f-tricalcium phosphate  (TCP), bioactive glasses, calcium sulfate, glass ionomers,  hydroxyapatite (HA), etc. are some of the synthetic graft  materials available in the market, which can be used  instead of autogenous bone grafts, for filling up the defect  after enucleation. The blood clot in the cystic cavity is  stabilized by these synthetic grafts, thereby minimizing  the postoperative infection. These synthetic grafts are  also osteoconductive in nature and promote new bone  formation by facilitating the migration of osteoprogeni-  tor cells [24, 25].   3. If it is possible to enucleate without  jeopardizing the vitality & integrity of teeth &  adjacent vital structures.   4. Enucleation as a second stage procedure after  decompression or marsupialization.   3. Entire pathological tissue is removed, which is  available for histopathological examination.   4. Chances of recurrence are reduced with  adjunct procedures. (Elimination of satellite cysts   6. Maintainance of oral hygiene is easy.  7. Enucleation with water tight suturing  eliminates the need for long postoperative   1. After primary closure, it is not possible  to observe the healing cavity.   3. Large cyst enucleation may end up in  fracture or perforation/damage to  adjoining soft tissues.   6. Enucleation with fragmentation in  inaccessible areas may end up in  recurrence.    27.8.4 Block Resection, With or Without  Preservation of the Continuity  of the Jaw    Resection of a jaw bone can be done either as (1) marginal  resection procedure or (2) segmental resection procedure. In  marginal resection procedure, the lesion is smaller, which is  excised in toto, and hence, it is possible to maintain the continu-  ity of the jaw bone by preserving the portion of the uninvolved  bone. In segmental resection procedure, since the lesion is  extensive, the complete segment/portion of maxilla or mandible  is sacrificed, and hence, continuity of the jaw bone is lost after  this radical treatment. Since this procedure ends up in consider-  able morbidity, there is always a need for rehabilitating the  patient functionally and esthetically by various reconstructive  measures [26]. Many researchers felt that there is no need for  aggressive therapy in the case of cystic lesions, as their manage-  ment can be done by using relatively noninvasive means [26].   Blanas et al. [21] carried out a systematic review and  found that following resection, there was 0% recurrence rate,  but it is always associated with the high morbidity rate. Their  study suggested that enucleation followed by the use of  Carnoy’s solution gives similar low recurrence rates, as  resection, without unwarranted radical surgery. Complete  resection of the mandibular/maxillary bone is considered as  morbid overtreatment for large locally aggressive cysts. The  only main disadvantage of a conservative treatment is pro-  longed therapeutic time [27].   In this chapter, we will be discussing only briefly  Dentigerous and Keratocyst varieties prototypes.    Dentigerous Cysts or Follicular Cysts, The term dentigerous  is a Latin word, literally means “tooth bearing/producing”.  Paget in 1853 first coined the term “Dentigerous cyst”, in  this entity, there is an enclosure of the crown of a tooth,  which is unerupted, and cyst is attached to the CE junction  and is formed by the enlargement of its follicle [1]. There is  always an association of this cyst with the crown of fully or  partially impacted or submerged tooth (Fig. 27.12).  Depending on the location and extent of the cystic degen-  eration in relation to the crown of an unerupted tooth, the cyst  can have central, lateral, or circumferential variety [28]. In cen-  tral type, initially, the crown may be enclosed by a cyst sym-  metrically, but as it expands, crown of the mandibular third  molar may be shifted to the inferior border of the mandible or    migrated high up in the ascending ramus and similarly, maxil-  lary canine or third molar may be seen at the orbital floor or  high in maxillary sinus. The lateral type will be because of  expansion of cyst only on one particular side of the crown, and  it will be seen in cases of partially erupted mandibular third  molars. In circumferential type, the radiograph will show a  radiolucency enveloping the entire tooth (Fig. 27.13).    Hyperplastic follicle-Normal follicular space size is 2-3 mm;  if it exceeds 5 mm, then dentigerous cyst should be  suspected.   Differential diagnosis of unicystic ameloblastoma, an  odontogenic keratocyst, Calcified odontogenic cyst,  Ameloblastic fibroma, Adenomatoid odontogenic tumor, or  radicular cyst must be considered in such cases comparable  to the radiographic details, but the incidence of all the above  lesions is rare in the first decade of life. Since radiographs  alone cannot differentiate the above-mentioned lesions, a  histopathological examination should be performed.    Fig. 27.13 Types of dentigerous cysts and their radiological picture of central, lateral, and circumferential type (a—c)    3  : =  ©Association of Oral and Maxillofacial Surgeons of India    Thin layer of nonkeratinizing stratified squamous epithelium  lining the lumen is seen, and no rete ridges are seen.  Connective tissue wall shows bundles of collagen fibers;  sometimes, many odontogenic epithelial islands are seen.  The cystic lumen contains thin, watery, and yellowish fluid  (Fig. 27.14).    1. As it is known that dentigerous cysts have potential for  neoplastic proliferation in the form of cystic or mural  ameloblastoma, in these cases, there is a nodular thick-  ening at some places in the cystic wall, which cannot be  discerned clinically, but is a tumor manifestation itself,  and therefore, histopathologist is requested to carry out  thorough gross and microscopic examination of the  whole specimen for nodular thickening, etc. in the cystic  wall.   2. Epidermoid carcinoma—cyst lining, which shows long-  standing keratin metaplasia, should be considered as a  marker for the initiation of carcinomatous changes.   3. Mucoepidermoid carcinoma—dentigerous cyst may  contain cells with the potential of mucus secreting abil-  ity, which may transform into mucoepidermoid carci-  noma [28].    OKC has got its name because it exhibited keratinization of  cystic lining. Its lumen contains a cheesy material resem-  bling keratin debris and clear fluid. It is a Dilemmatic,  Distinctive, Odontogenic Developmental, and Intraosseous  cyst of epithelial origin of Oral & maxillofacial region, with  specific characteristics, such as rapid Infiltrative growth,  aggressive nature, high recurrence rate and defined histo-  pathological features [26, 27]. Since 1956, for the last six  decades, many researchers started focusing on this entity.  Journey of this changing nomenclature is pretty interesting  (Box 27.12).   Dermoid cyst (Mikulicz) identified & described as a  part of familial jaw condition   Aggressive growth/high tendency for recurrence rate  (described by Pindborg & Hansen)   OKC as preferred term for keratinized cysts (WHO)  Keratinizing Cystic Odontogenic Tumor( KCOT)  (Reichart & Philipsen)    In 2004, Reichart and Philipsen suggested a new classifi-  cation for the odontogenic tumors, redesignated OKC as  Keratinizing cystic Odontogenic Tumor (KCOT), and put it  under the subcategory of “benign neoplasm of odontogenic  epithelium with mature, fibrous stroma due to its propensity  for local destruction, aggressive biological behavior,  and high recurrence rate and mitotic figures seen in the  suprabasal layers [29]. Shear had re-emphasized that OKC  shows increased proliferative activity & high recurrence ten-  dency and stressed on association of OKC with the Gorlin-  Goltz syndrome/Nevoid Basal Cell Carcinoma syndrome  (NBCCS). Some of these OKCs had association with the  PTCH | gene mutation and increased immunohistochemical  expression of proliferation markers Ki 67 and presence of  PCNA (Proliferating cell nuclear antigen marker of cell rep-    lication) and p53 in KCOT. All this evidence led to change in  nomenclature by WHO in 2005 [10].   This shift in tumor category suggested change in manage-  ment protocol for OKC, which created a lot of skepticism,  and the concept was not widely accepted, with the reason  being not all OKCs possess identifiable PTCH mutation.  There were no clear-cut suggestions such as neoplastic title  was to be applied to all OKC or to just a small subset. All  relevant sequencing data on the odontogenic keratocysts has  not yet been presented and still under research.   Researchers have suggested that marsupialization can  revert the fragile cystic lining epithelium to normal oral  mucosa or from parakeratin to orthokeratin type [30, 31].   Extensive debate (for 12 years) over putative neoplastic  nature of the lesion took place. So, in 2017, a WHO expert  panel declared that there is no strong affirmation to rational-  ize to label OKC as a neoplasm, and therefore, Odontogenic  Keratocyst-OKC should be put back in cyst category and the  term keratocystic odontogenic tumor (KCOT) was elimi-  nated from the new classification (Boxes 27.13, 27.14, 27.15,  27.16, 27.17 and 27.18).    Box 27.13 Epidemiology of OKC  Incidence: Second most prevalent cysts of odontogenic  origin (10-12% of all odontogenic cysts) [32].   Age: Wide age range. Range of occurrence between  the Ist and 9th decades of life. Bimodal age distribu-  tion (first peak at 20-30 & second at 50-60 years of  age) and Predominantly in younger patients in syn-  dromic cases.   Sex: Male predilection (1.6:1 ratio), More Female  predilection in syndromic cases.    Box 27.14 Site Predilection of OKC  Central intraosseous Lesion—Thrice more prevalent  in mandible. Seen more at various sites in following  order-angle-ascending ramus, maxillary third molar  region (may involve sinus, nasal floor premaxilla, pres-  ence of impacted third molar seen, and occasionally  floor of orbit involvement), mandibular, premolar area,  and maxillary canine.   e Syndromic: Multiple OKCs are often one of the  manifestations of genetically inherited Nevoid  Basal cell Carcinoma Syndrome (NBCCS), Gorlin-  Goltz syndrome, etc. [In syndromic cases, multiple  cysts can be seen in one patient at a time or during  lifetime occurrence, many cysts can happen at dif-  ferent times [34].    e Basal cell nevus syndrome, Nevoid Basal cell  Carcinoma Syndrome (NBCCS), or Gorlin-Goltz  syndrome   As per the occurrence of satellite/daughter cysts &  squamous islands found in the cystic wall (Kahraman  et al. [35]) (Fig. 27.17)   Group II. With few satellite/microcysts & squa-  mous islands in the cystic lining less than  (10-27%)   Group Il. Abundant presence of satellite/daughter  cysts and squamous islands (6-10%)   2. It can originate from downgrowth or implantation follow-  ing trauma of the offshoots of epithelial basal layer of the  oral gingiva and mucosa [27]. Islands of Epithelium and/  or daughter cysts are seen in 50% of the cases, in overly-    Box 27.18 Reasons for Recurrence of OKC (13-62%;  Nakamura et al. [36])   Epithelial lining is weakly attached to capsule  Extension of the cyst into cancellous bone   Dental lamina remnants in bone/overlying mucosa  In the case of perforation of the cortex, cyst lining  adheres to adjoining bone or buccal or lingual  mucosa (especially, lingual perforation is difficult  to access during enucleation)    ing mucosa. (In the past designated as basal cell hamar-  tias). Genetic factors are also always key players,  especially PTCH gene aberration.    Unlike other cysts, lesion grows by extension in medullary  space in anteroposterior direction, compared to osmotic  expansion.    Finger-like projections are seen in marrow spaces, and  enlargement goes on relentlessly along the path of least  resistance. When it reaches a considerable size, it expands  buccolingually also (Figs. 27.15 and 27.16).    OKC is a great mimic; many times, the radiographic picture is  nonpathognomonic. Radiographically, the following differen-  tial diagnosis for Odontogenic Keratocyst has been suggested:   Dentigerous cyst, residual cyst, radicular cyst, lateral  periodontal cyst, Nasopalatine cyst, Unicystic/multicystic  ameloblastoma, A-V malformation, fibro-osseous lesion at  initial stages, Benign intraosseous neoplasms, traumatic  cyst. Patients with multiple jaw cysts should always be eval-  uated for basal cell nevus syndrome.    ¢ Cheesy, straw color, caseous, dirty milky white semifluid,  and viscoid content-Keratin-varying consistencies reflect  various densities of keratinous debris.   ¢ Protein content less than 3.5/4 g per 100 ml by electro-  phoresis, mostly albumin is present.   e Exfoliative cytology/smear is stained & examined for  keratin cells, and Estimation of Keratocyst Antigen  (KCA) and Lactoferrin levels is helpful.    Fig. 27.15 OPG showing how lesion grows in medullary space (in anteroposterior direction), multiloculated radiolucency in left angle, and    Incidence of these lesions is seen more in younger age group ° It should be used as a last alternative method  and the supportive evidence of success of conservative treat- ° Resection of the jaw bone results in morbidity and requires    ment options like marsupialisation for large expanding extensive reconstruction/rehabilitation, which is unwar-  OKCs or two-staged surgical procedures, plus the fact of ranted in the treatment of benign lesions, and hence, most  alteration of the remaining epithelium, i.e., return to more of the times, more conservative approaches are sought.  normal oral epithelium after decompression/marsupialisa-   tion has prompted many to opt for these procedures. The Absolute indications    Fig. 27.16 Multiple cysts in the  same individual, involving both  maxilla and mandible    HISTOPATHOLOGIC CRITERIA OF OKC-SHEAR & PINDBORG (1960-62)  _ © Thin, collapsed and folded, corrugated lining    e Zone of uniform parakeratinized stratified squamous epithelium  5-8 cell layers with no rete pegs    e Picket fence / tombstone appearance of hyperchromatic palisaded  basal cells with reversed polarity   e After 5 years of follow-up, once in 2 years as long as  patient cooperates    It is also known as bifid rib syndrome or Gorlin and Goltz  syndrome or multiple jaw cyst syndrome. This is a genetically  inherited uncommon affliction with autosomal dominant  trait/inheritance and high penetration.   This syndrome’s complex manifestations include relative  frontal bossing, Ocular hypertelorism, brain tumors, midface  hypoplasia, mandibular prognathism, mental retardation,  schizophrenia, multiple basal cell nevi/epitheliomas on the  skin, calcification of the falx cerebri, bifid ribs and vertebral  anomalies, palmar pitting (the pits later develop into basal  cell carcinoma), ovarian tumors, CNS disturbances, hypogo-  nadism in males,cleft lip and palate, etc., and 50% of cases  show multiple KCOT-now OKCs. Multiple KCOTs (OKCs)  are indicative of basal cell nevus syndrome until diagnosed  otherwise. 5% of the patients with KCOT/OKC are diag-  nosed having basal cell nevus syndrome. Early identification  of these patients with their associated manifestations along  with proper treatment planning and long-term follow-up will  improve the long-term survival rate and quality of life.    Cysts of the jaw bones are considered as one of the most  common pathologies in the oral and maxillofacial region.  Various tumors mimic the clinical features of cysts and, thus,  can be confused with the same. Radiography alone cannot be  the diagnostic tool to distinguish various jaw cysts. Cysts are  benign lesions, but few will show locally aggressive and  destructive behavior. The detailed present and past history of  the patient accompanied by a thorough clinical examination  along with aspiration biopsy will lead to probable differen-  tial diagnosis. Both conservative and aggressive surgical    treatment modalities have been used in the past to treat oro-  facial cysts with variable results, depending on the type of  cyst. Correct final diagnosis, thorough planning, meticulous  surgery with stringent protocols, and watchful long-term  postoperative follow-up will ensure high success rate.    1. Shear M, Speight PM, editors. Cysts of the oral and maxillofacial  regions. 4th ed. Oxford: Blackwell Munksgaard; 2007.   2. Kramer IRH, Pidborg JJ, Shear M. Histological typing of odonto-  genic tumors. Berlin: Springer-Verlag; 1992.   3. Regezi J, Sciubba J, Jordan R. Oral pathology: clinical pathologi-  cal correlations. 4th ed. St. Louis: Elsevier Health Sciences; 2016.  p. 244-54.   4. Browne RM. The pathogenesis of odontogenic cysts: a review. J  Oral Pathol. 1975;4(Suppl 1):31-46.   5. Harris M, Toller P. The pathogenesis of dental cyst. Br Med Bull.  1975;31(Suppl 2):159-63.   6. Shrestha P, Yamada K, Higashiyama H, Takagi H, Mori  M. Epidermal growth factor receptor in odontogenic cysts and  tumors. J Oral Pathol Med. 1992;21(Suppl 7):314—-7.   7. Sakamoto S, Sakamoto M, Goldhaber P, Glimcher M. Collagenase  and bone resorption: isolation of collagenase from culture medium  containing serum after stimulation of bone resorption by addition  of parathyroid hormone extract. Biochem Biophys Res Commun.  1975;63(Suppl 1):172-8.   8. Harvey W, Guat-Chen F, Gordon D, Meghji S, Evans A, Harris  M. Evidence for fibroblasts as the major source of prostacyclin  and prostaglandin synthesis in dental cyst in man. Arch Oral Biol.  1984;29(Suppl 3):223-9.   9. Meghji S, Harvey W, Harris M. Interleukin 1-like activity in cys-  tic lesions of the jaw. Br J Oral Maxillofac Surg. 1989;27(Suppl  1):1-11.   10. Barnes L, Eveson JW, Reichart P, Sidransky D. Pathology and  genetics of head and neck tumours: WHO classification of tumours.  3rd ed. Lyon: IARC Press; 2005. p. 107-62.   11. Wright JM, Vered M. Update from the 4th edition of the World  Health Organization; classification of head and neck tumours:  odontogenic and maxillofacial bone tumors. Head Neck Pathol.  2017;11(Suppl 1):68-77.   12. Martin L, Speight PM. Mini-symposium: pathology of the jaws.  Odontogenic cysts. Diagn Histopathol. 2015;21:359-69.   13. Olojede O, Adisa AO, Effiom O, Warith AA. Cysts of the orofacial  region: a clinicopathologic review of 403 Nigerian cases. East Afr  Med J. 2017;94(Suppl 2):116-24.   14. Das AK, Prajapati VK. Concentration of proteins in intra osseous  jaw cysts as an adjunct to diagnosis. Int J Sci Stud. 2015;2:150-S.   15. Toller PA, Holborow EJ. Immunoglobulins and immunoglobu-  lin containing cells in cysts of the jaws. Lancet. 1969;2(Suppl  7613):178-81.   16. Smith AJ, Matthews JB, Mason GI, Browne RM. Lactoferrin in  aspirates of odontogenic cyst fluid. J Clin Pathol. 1988;41(Suppl  10):1117-9.   17. Pogrel MA. Treatment of keratocysts: the case for decompres-  sion and marsupialization. J Oral Maxillofac Surg. 2005;63(Suppl  11):1667-73.   18. Voorsmit RA, Stoelinga PJ, van Haelst UJ. The management of  keratocysts. J Maxillofac Surg. 1981;9:228-36.   19. Sun J, Wu J, Zhou N, Meng N, Lin Y. A prospective study of jaw  odontogenic keratocyst treated by multidisciplinary sequential  treatment. Int J Oral Maxillofac Surg. 2009;38(Suppl 5):537.    Morgan TA, Burton CC, Qian F. A retrospective review of treatment  of odontogenic keratocyst. J Oral Maxillofac Surg. 2005;63(Suppl  5):635-9.   Blanas N, Freund B, Schwartz M, Furst IM. Systematic review of  the treatment and prognosis of the odontogenic keratocyst. Oral  Surg Oral Med Oral Pathol Oral Radiol Endod. 2000;90(Suppl  5):553-8.   Dashow JE, McHugh JB, Braun TM, Edwards SP, Helman JI, Ward  BB. Significant decreased recurrence rates in keratocystic odon-  togenic tumour with simple enucleation and curettage using car-  noy’s versus modified carnoy’s solution. J Oral Maxillofac Surg.  2015;73(Suppl 11):2132-5.   Schmidt BL, Pogrel MA. The use of enucleation and liquid nitro-  gen cryotherapy in the management of odontogenic keratocysts. J  Oral Maxillofac Surg. 2001;59(Suppl 7):720-5-6-7.   Ochandiano CS. Bone cavity filling with alloplastic material in  maxillofacial surgery. Rev Esp Cir Oral Maxillofac. 2007;29(Suppl  1):21-32.   Ettl T, Gosau M, Sader R, Reichert TE. Jaw cysts—filling or no  filling after enucleation? A review. J Craniomaxillofac Surg.  2012;40(Suppl 6):485-93.   Stolinga PJ. Long term follow-up on keratocysts treated according  to a defined protocol. Int J Oral Maxillofac Surg. 2001;30(Suppl  1):14—25.   Giuliani M, Grossi GB, Lajolo C, Bisceglia M, Herb KE. Conservative  management of large odontogenic keratocyst: report of acase and review  of the literature. J Oral Maxillofac Surg. 2006;64(Suppl 2):308-16.    Neville BW, Damn DD, Allen CM, Bouquot JE. Oral and maxil-  lofacial pathology. 3rd ed. Philadelphia: WB Saunders; 2004.  Reichart P, Philipsen H. Odontogenic tumours and allied lesions.  3rd ed. New Malden: Quintessence Publishing; 2004.   Wushou A, Zhao YJ, Shao ZM. Marsupialization is the opti-  mal treatment approach for keratocystic odontogenic tumour. J  Craniomaxillofac Surg. 2014;42(Suppl 7):1540-4.   Maurette PE, Jorge J, de Moraes M. Conservative treatment pro-  tocol of odontogenic keratocyst: a preliminary study. J Oral  Maxillofac Surg. 2006;64(Suppl 3):379-83.   Chirapathomsakul D, Sastravaha P, Jansisyanont P. A review of  odontogenic keratocysts and the behaviour of recurrences. Oral  Surg Oral Med Oral Pathol Oral Radiol Endod. 2006;101(Suppl  1):5-9.   Chuong R, et al. The odontogenic keratocyst. J Oral Maxilllofac  Surg. 1982;40:797-802.   Auluck A, Suhas S, Pai KM. Multiple odontogenic keratocysts:  report of a case. J Can Dent Assoc. 2006;72(7):65 1-6.   Kahraman D, Gunhan O, Celasun B. A series of 240 odontogenic  keratocysts: should we continue to use the terminology of “kera-  tocystic odontogenic tumour” for the solid variant of odontogenic  keratocyst? J Craniomaxillofac Surg. 2018;46(6):942-6.  Nakamura N, et al. Marsupialization for odontogenic keratocyst:  long term follow up analysis of the effects and changes in growth  characteristics. Oral Surg Oral Med Oral Pathol Oral Radiol Endod.  2002;94(Suppl 5):543-53.    Open Access This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.  org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropri-  ate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.    The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in    a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.    28.1 Introduction  The region of Head and Neck has a wide range of pathologi-  cal disorders due to the complex nature of the tissues in this  region. The tooth-forming tissues can give rise to a wide  array of tumours, both benign and malignant. They vary in  size from tiny swelling to a large variety, causing cortical  bone perforation with the displacement of the adjoining nor-  mal anatomic structures. Odontogenic tumours are slow  growing and generally non-aggressive, with aggressive  behaviour shown by certain tumours.   It is important for the clinician to have a thorough knowl-  edge of the pathology, clinical as well as radiological presen-  tation in order to manage these conditions.   “Odontogenic tumours and tumour-like lesions constitute a  group of heterogeneous diseases that range from hamarto-  matous or non-neoplastic tissue proliferations to benign neo-  plasms and finally malignant tumours with metastatic  potential. They are derived from epithelial, ectomesenchy-  mal and/or mesenchymal elements of the tooth-forming  apparatus. Odontogenic tumours are rare, some being  extremely rare, but can pose a significant diagnostic and  therapeutic challenge.’   The WHO first classified benign odontogenic tumours in  1971 followed by in 1992, 2005 and the recent classification  was in 2017. The origin-based sub-classification was first  defined in 1992, which is still in use, i.e. the tumours are sub-  classified into Epithelial origin, Mixed origin and    Electronic Supplementary Material The online version of this chap-  ter (https://doi.org/10.1007/978-98 1-15-1346-6_28) contains supple-  mentary material, which is available to authorized users.    A. K. Shah (4)  Department of OMFS, Rajarajeswari Dental College,  Bangalore, India    © The Association of Oral and Maxillofacial Surgeons of India 2021    Mesenchymal origin. The metastasising (malignant) amelo-  blastoma is included in epithelial origin tumour in 2017  WHO classification and desmoplastic ameloblastoma was  excluded from the classification of benign odontogenic  tumour. In 1992 classification, adenomatoid odontogenic  tumour (AOT) was considered under mixed origin but in  2005 and 2017 classification, it is included in the epithelial  origin tumour [2].   The dentinogenic ghost cell tumour (DGCT) comes under  the spectrum of ghost cell lesions. Gorlin et al. in 1962 first  described calcifying odontogenic cyst (COC) as the earliest  ghost cell lesions. In 2005 WHO classification, COC is  renamed as calcifying cystic odontogenic tumour (CCOT).  Fejerskov and Krogh used the term calcifying ghost cell  odontogenic tumour for DGCT in 1972. Dentigerous ghost  cell tumour term was given by Praetorious et al. in 1981,  which is still retained in 2005 and 2017 WHO classifica-  tion. In between, Shear in 1983 used the term dentinoamelo-  blastoma, whereas Ellis and Shmookler proposed epithelial  odontogenic ghost cell tumour. Hong et al. in 1991 suggests  the term epithelial odontogenic ghost cell tumour [3, 4].   e Ameloblastoma, conventional  Ameloblastoma, unicystic type  Ameloblastoma, extraosseous/peripheral type  Metastasising (Malignant) ameloblastoma    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1-15-1346-6_28    It is the most common odontogenic tumour arising from  odontogenic epithelium.    e Epithelial cell rests of Malessez, which are the  residual epithelium of the tooth-forming apparatus.   e Heterotopic epithelium from the extra-oral sites  such as pituitary gland    Edited 2017 WHO classification of odontogenic tumours  has simplified the classification of Ameloblastomas. It has  removed the various pathologically descriptive classifica-  tion terminologies such as follicular, plexiform, basaloid,  granular or desmoplastic as these terminologies do not have  any relevance to clinical behaviour. Conventional-type  Ameloblastomas are characterised by multilocular, expand-  ing behaviour. The histological margin is characterised by    the infiltrating margin, requires wide excision with a mar-  gin of 0.5—1 cm of normal bone, or one anatomical layer if  grown out of the confines of the bone. That is if bony cortex  invaded, then take muscle or subcutaneous tissue to main-  tain periosteum as anatomical barrier.    ‘It is a true neoplasm of enamel organ-type tissue, which  does not undergo differentiation to the point of enamel for-  mation” proposed by WHO. Robinson [7] defined it as a  “Non-functional, unicentric, intermittent in growth, anatom-  ically benign and clinically persistent type of tumour’    It represents 19.3-41.5 % of all odontogenic tumours [8, 9].  Posterior Mandible is the commonest site of occurrence in  almost 80% of ameloblastomas [10]. It occurs over a broad  range; cases ranging from adults older than 90 to the children  younger than 10 years. Most frequently, they occur in the sec-  ond and fourth decade of life. Some authors found no gender  predilection [11] while many studies showed female predilec-  tion [12] between the first and the third decade of life [13].    ¢ Ameloblastomas commonly originate within the bone,  thus often they are detected on routine dental x-rays or on  orthopantomogram (OPG).   ¢« Computed tomography (CT) is very helpful in surgical  planning by giving exact cortical destruction and soft  tissue extension, it typically demonstrates well-defined  radiolucent uni/multilocular lesions [15]   ¢ Magnetic resonance imaging (MRI) is very helpful in  maxillary lesions for defining the extension of ameloblas-  tomas into paranasal sinuses, orbit and skull base [16]    In 2005 WHO classification, the Ameloblastoma, solid/  multicystic type, was mentioned, which is replaced by  Ameloblastoma alone in 2017 classification again.  Historically, the Ameloblastoma is classified into Unicystic  and Multilocular or Solid.   The solid/multicystic or intra-osseous ameloblastoma is  locally invasive, slow-growing and odontogenic tumour of  epithelial origin with a high rate of recurrence if not removed  or treated properly. It has no tendency to metastasise. It  invades the bone marrow spaces.   It has no gender predilection and occurs equally in both sexes.  Most commonly diagnosed between 30 and 60 years of age. The  posterior mandible region affected in more than eighty percent of  the tumour cases. It may present as variably sized swelling of  jaws. Pain and paraesthesia are rare. It usually appears multilocu-  lar (soap bubble appearance) in radiographs.   It occasionally is associated with an impacted tooth and  causes expansion of the bony cortex, with the possibility of  resorption of roots of the involved teeth [17, 18]. The most  common histological patterns found are plexiform and fol-  licular types. The others are desmoplastic, acanthomatous,  granular and basal [2]. To confirm the diagnosis, the combi-  nation of imaging (plain as well as computed tomography)  and biopsy can be performed.   The tumour infiltrates through the medullary spaces and  might erode the cortical bone. After resorbing the cortical  bone, it may extend into the adjacent tissues. The maxillary  tumours of the posterior region tend to obliterate the maxil-  lary sinus and may extend to infiltrate the skull base.    The treatment depends on the best judgement of the sur-  geons and individual status of the patient. The surgical plan-  ning should be based on the lesions present in the mandible  or maxilla. The maxilla has got higher percentage of cancel-  lous bone, which facilitates the spread of tumour in compari-  son to the mandible having thick and dense cortical plates,  which limit the spread of neoplasm.    The treatment of the conventional/multicystic variant is  classified into radical and conservative. The conservative  methods include   e Surgical excision with other adjuvant therapy such  as cryotherapy or use of carnoy’s solution    Radical treatment includes resection of bone. At least  1 cm of the surrounding healthy tissues should be removed  along with the tumour in cases of cortical bone perforation  because if tumour cells are left behind, they may give rise to  locoregional recurrence even several years after resection  [20]. There is a 1.26-fold increase in the chance of the recur-  rence rate with the increase in the size of every 10 mm of  tumour [21].   In mandible, resection can be carried out on the basis of  the extension of the lesion in the form of alveolectomy,  marginal mandibulectomy, segmental resection, hemiman-  dibulectomy or hemimandibulectomy with disarticulation  depending on the extension of the tumour. Based on the  extension of tumour, maxillectomy (partial, total or subto-  tal) has been performed in radical treatment of maxillary  lesions [22].   Enucleation and curettage are inadequate because the  tumour invades the adjoining cancellous bone. However,  some conditions in which it is carried out are given below:  28.4.1.1 Indications of Enucleation and Curettage  1. In medically compromised patient or conditions in which   2. Very young or old patient who is not willing for segmen-  tal resection.    If enucleation and curettage has to be done, it is prefera-  ble to be carried out in association with chemical cauterisa-  tion with the help of modified carnoy’ solution and peripheral  ostectomy.   The surgical treatment of solid/multicystic variant is con-  troversial. A high rate of recurrence is reported if it is not  adequately excised or resected. According to some authors,  the initial treatment should be conservative as the tumour has  low metastatic potential and the radical treatment should be  done in cases of recurrence. While others believe that when-    ever possible complete removal of the tumour with preserva-  tion of lower border of the mandible will be the treatment of  choice [23].   Conservative treatment has a recurrence rate ranging from  33 to 90%, as compared to the rate of recurrence by radical  treatment, i.e. 7—25% in the literature. However, the patients  experience serious functional and aesthetic impairments  with radical treatment [24, 25]. Hasegawa et al. [26] also  reported the recurrence rate of 43.5% following conservative  management.   Enucleation alone showed the highest rate of recurrence  amongst all the modalities of conservative management [27].  According to Esquillo ME [28], small multicystic and solid  lesions can be treated by marsupialisation with good results.  This will maintain good facial aesthetics of the patient, less-  ening the treatment cost but patients have to keep on long-  term follow-up.   About 40% of intra-osseous Ameloblastomas did not  recur after conservative management, which led to the con-  clusion that the small intra-osseous ameloblastomas can be  treated with conservative management initially, leading to  fewer post-operative complications and if the lesion recurs,  the radical treatment can be carried out in the second-stage  surgery aggressively [29].   Almeida AC et al. [30] in the systematic review and meta-  analysis concluded that the bone resection should be the  treatment of choice for primary multicystic ameloblastoma,  also the chances of recurrence were 3.15 fold more when the  conservative treatment was performed in comparison to radi-  cal treatment. Hendra FN et al. also suggest that the rate of  recurrence was less when radical treatment was opted for the  treatment of intra-osseous ameloblastoma in their systematic  review and meta-analysis [31].   Antonoglou GN and Sandor GK [32] in the systematic  review and meta-analysis concluded that no strong recom-  mendations have been made regarding the treatment options  regarding the intra-osseous ameloblastoma. However, radi-  cal treatment in the form of resection is the treatment of  choice for solid/multicystic ameloblastoma.   Pogrel MA and Montes DM [33] concluded that  Enucleation alone should not be the choice of treatment for  multicystic or solid lesions. In the case of maxilla, partial  maxillectomy and in mandibular lesions, segmental resec-  tion with | cm margin will be preferred to avoid recurrence.   Sampson DE and Pogrel MA [34] suggested the manage-  ment algorithm for management of mandibular ameloblas-  toma, which is, in the case of mandibular ameloblastoma, if  lesion is less than | cm, in plain radiograph, then curettage  and cryotherapy is the treatment of choice and patient is to be  kept on long-term clinical and radiological follow-up. If the    lesion is more than | cm, CT scan is to be done. If findings  are positive, then segmental resection with involved soft tis-  sue is carried out with suitable reconstruction and patient is  to be kept on long-term clinical and radiological follow-up.   Sammartino et al. advocated the following treatment plan  in Mandibular tumour management [24]. In the cases of  small lesions, box resection has to be done and the patient  has to keep for long-term follow-up to 10 years. For large  lesions if cortical perforation is there on CT examination.  Then segmental or marginal resection has been carried out  along with excision of overlying soft tissues, if cortical per-  foration is absent then curettage is the choice of treatment  with 0.5—1 cm of clinically uninvolved surrounding bone. In  both cases, 10-year followup of patients is mandatory. If no  recurrence occurs, orthopantomogram has to be done in  every 2-3 years on the other hand if recurrence occurs, then  the first or second small recurrence can be treated with mar-  ginal resection while for the third recurrence, the segmental  resection is the choice of treatment.   to the Anatomic Locations  28.4.2.1 Mandibular Anterior Region (Canine  to Canine)  According to Gardner, anterior mandible should be  approached conservatively because no important major  anatomic structures are present in the anterior mandible.  However, if curettage is used as a choice of treatment,  recurrence is anticipated and it is preferred in smaller  lesions. Always an attempt should be made to preserve the  inferior border of mandibular in the anterior region  because the tumour infiltration is less, due to the thick  cortical bone of the symphyseal region. In large lesions  with cortical perforation, marginal mandibulectomy will  be the choice of treatment followed by long-term follow-  up (Fig. 28.1). After marginal mandibulectomy, the lower  border of mandible is reinforced with a reconstruction  plate, to avoid pathological fracture in future (Videos 28.1  and 28.2).   to Condyle)  Marginal mandibulectomy should be the choice of surgical  treatment for the posterior mandible and body region while  maintaining the inferior and posterior border whenever pos-  sible for solid/multilocular variant. Maxillomandibular fixa-  tion might be required after marginal resection without    Fig. 28.1 Orthopantomogram representing marginal mandibulectomy,  lower border protected with reconstruction plate    continuity defects to avoid the chances of pathological frac-  ture. A reconstruction plate may be contoured before resec-  tion, in order to maintain the normal anatomic relationship  between proximal and distal segments by marking the points  of screw fixation on the normal bone. In recent years, man-  dibular reconstruction using intra-oral microvascular anasto-  mosis following segmental resection in cases of  ameloblastomas has been carried out with great success.  Most commonly, free fibular graft has been used for the  same, followed by dental rehabilitation with the help of den-  tal implants [35, 36].    28.4.2.3 Anterior Maxilla (Canine to Canine)  Goodcell JF reported 2% ameloblastomas in anterior maxilla  [37]. However, Sehdev MK et al. show 9% of ameloblasto-  mas occurs in the canine and incisor region [38]. Less-  aggressive treatment has been advocated in anterior maxilla  when compared to posterior, because a sufficient distance  from the vital structures allows being less radical. Radical  treatment in the form of partial or total maxillectomy may  result in significant deformity.   Ameloblastoma occurs 47% in the molar region, 15% in the  maxillary antrum and floor of the nose, while 9% in the pre-  molar region.   Lack of cortical bone in maxilla makes it much more  dangerous than mandibular ameloblastomas. The definitive  treatment becomes difficult in the posterior maxillary    region because tumours are not well confined by the thin  maxillary cortical bone and easily spread beyond the max-  illary bone boundaries. Early detection is also very diffi-  cult. Posterior maxillary tumours are rarely treated by  conservative management. Extra-oral or intra-oral resec-  tion of the tumour is carried out, sometimes Le fort I down  fracture is required to access the tumours of maxillary sinus  or the tumour invades the posterolateral wall of the maxil-  lary sinus.   Weber Fergusson incision and mandibulotomy can be  used for accessing the tumors of maxilla, pterygoid and  infra temporal fossa. When reconstruction of the defect  after maxillectomy has been planned by temporalis mus-  cle, Rai A et al. [39] advocated use of Borle’s extension  weber fergusson incision.    Based on this options starting from the most conser-  vative to most radical are:  1. Marsupialisation  2. Enucleation or curettage  3. Peripheral ostectomy or En bloc resection  4. Segmental resection   . Packing cavity and healing by secondary intention  . Reconstruction plate with primary mucosal closure  . Reconstruction plate with free bone graft    excellent access for posterior tumours especially  when access to the pterygoids/intratemporal region  is required   . To establish the arch form, width and alveolar height.  . To establish the bone continuity and maintain facial    Immediate reconstruction is usually performed with the help  of microvascular-free flaps, harvested from fibula, scapula,  iliac crest and ribs. For the reconstruction of the mandible,  free fibula flap is the treatment of choice. It is superior to  iliac crest graft. Scapula flap for maxillary reconstruction  may be a good alternative because of its long pedicle and  good bone quality. For soft tissue reconstruction, the radial  forearm-free flap is the choice of treatment. Most of the sur-  geons still prefer to use Titanium reconstruction plate for  reconstruction when free flaps are not possible as an immedi-  ate reconstruction modality. Delayed reconstruction (second  stage) can be performed for reconstruction with the help of a  titanium reconstruction plate. The immediate reconstruction  significantly improves the patients’ health-related quality of  life, many patients prefer immediate reconstruction [40].   Lawson et al. [41] reported 90% success rate with delayed  reconstruction in comparison to immediate, which is 46%  using non-vascularised bone grafts.   Autogenous bone graft selection (Vascularised free flaps vs  non-vascularised bone graft) depends on following factors    1. Experience of the surgeon  2. Contour and size of the defect  3. Size and quality of the soft tissue available    The HCL classification [42, 43] is used as an aid in clas-  sifying mandibular defects. The defect from canine to canine,  i.e. the central defect is designated as ‘C’. The lateral seg-  ment defect excluding condyle designated as “‘L’ and when  condyle is included in resection with lateral mandible the  defect is designated ‘H’ (Fig. 28.2). The importance of this  classification indicates that reconstruction of lateral defect  can be done by straight bone segment while defect located  centrally required osteotomies.    28.5.1.1 Case Scenario 1 (Fig. 28.3a-g)  A 38 year old male patient reported to our outpatient depart-  ment with the chief complaint of painless swelling of lower  jaw since last 6 months (Fig. 28.3a). History of present illness  represents swelling initially was of lemon size and increasing  gradually to reach the present size, extending from right side  of the body region of the mandible to the ramus region of the  opposite side. On intra-oral examination, a diffuse swelling  was present from one side of the molar region extending to the  other side of the molar region of the mandible (Fig. 28.3b).  The orthopantomogram (Fig. 28.3c) and the CT scan  (Fig. 28.3d) showing the multilocular lesion extending from  the right side of the first molar to the ramus region of the  contralateral side. The incisional biopsy of the lesion con-  firmed the diagnosis of solid/multicystic ameloblastoma.  Under general anaesthesia, the resection of the lesion was  done, the complete resection of lesion was confirmed in the  specimen radiography (Fig. 28.3e). The reconstruction of the    defect was done with the help of microvascular free fibula  flap and with the titanium reconstruction plate (Fig. 28.3f),  post-operative OPG representing reconstruction (Fig. 28.3g).    The calcium phosphate cement (Hydro set) is the commonly  used material, which converts in situ to hydroxyapatite, serving  as an effective osteoontegrative and osteoconductive material  [44]. The other implantable material options include high-den-  sity porous polyethylene implants [45]. Using rapid prototype  models, the custom-made implants are commonly used for the  reconstruction of maxillofacial defects with good results [46].   The titanium mesh tray filled with autologous cancellous  bone blocks fixed with the residual segment of bone and also  titanium mesh cage filled with fresh bone marrow, recombi-  nant human bone morphogenic protein (BMP) and xeno-  genic bone mineral are used for reconstruction of mandibular  defect. The BMP is the key activator of bone induction [42].   Recent advances in mandibular reconstruction include  transport disc distraction osteogenesis, modular endopros-  thesis and tissue engineering. Dental implants are commonly  used in autogenous bone grafts for the rehabilitation of mas-  ticatory functions [42].    Robinson and Martinez [47] first described Unicystic  Ameloblastoma (UA) in 1977.    In 1988, Ackermann GL et al. [48] reclassified UA with  prognostic and therapeutic implications into three types    Type 1: Unilocular cystic lesions lined by epithelium exhib-  iting features of ameloblastoma.   Type 2: Epithelial nodules arising from cystic lining and pro-  jecting into the cyst lumen.   Type 3: The presence of invasive islands of ameloblastoma-  tous epithelium in the connective tissue wall of the cyst  and these islands may or may not be connected to the cyst  lining.    Most of the UA clinically and radiographically resemble deni-  gerous cysts in behaviour. Embedded teeth are associated with  some UA and hence resembles residual or primordial cysts.   UA most commonly occurs in the second and third decade  of life and have predilection to mandible [48]. UA many  times are associated with mandibular third molars. There  will be well-corticated unilocular and often pericoronal  radiolucency   A 14 year old female reported with swelling on the left side  of the ramus region for the past 3 weeks. OPG (Fig. 28.4a)  and PA view (Fig. 28.4b) showed a large unilocular radiolu-  cent lesion involving the whole of the ramus of the left man-  dible. Tooth bud of lower left third molar was absent. The  lesion seemed to arise from the impacted tooth bud of lower  left second molar and the lesion was also involving the roots  of lower left first molar. Under the provisional diagnosis of a  dentigerous cyst, the lesion was enucleated under anaesthe-  sia and primary closure was done and the impacted tooth bud  was removed in this case. The histopathology report was that  of an unicystic ameloblastoma with mural changes. The  child was on follow-up with no evidence of recurrence.    On histological examination, various situations may be  found such as shown in Fig. 28.5   3a. Ameloblastoma islands present in the connective  tissue wall of an apparently non-neoplastic cyst.   3b. Proliferation of ameloblastoma into the connective  tissue wall from cystic lining. (One of the Mural  variant)    Fig. 28.3 (a) Pre-operative extra-oral view. (b) Pre-operative intra-oral view. (c) Pre-operative OPG. (d) Pre-operative CT Scan of the patient. (e)  Specimen Radiography. (f) Clinical picture showing reconstruction with the reconstruction plate. (g) Post-operative OPG    Fig. 28.5 Various situations of Unicystic Ameloblastoma found on  Histological examination. 1. The ameloblastomatous epithelial lining.  2. An ameloblastoma nodule projects into the lumen (Luminal  Ameloblastoma). 3a. Ameloblastoma islands present in the connective  tissue wall of an apparently non-neoplastic cyst. 3b. Proliferation of  ameloblastoma into the connective tissue wall from cystic lining. (One  of the Mural variant)    Fig. 28.4 (a, b) OPG and PA view showing Unicystic Ameloblastoma    Conservative management has been advocated by cakarer  28.6.2 Management et al. in their study on large benign aggressive lesions of the  jaws, where they performed decompression followed by    UA treatment is controversial and can be grouped into Zheng et al. in 2019 published a long-term follow-up    Usually, initial treatment for UA is enucleation because  they appear clinically as cysts, and the histopathology  type is known only in the excision biopsy report as mural  changes can be picked by the pathologist only when the  full specimen is available. For histologic type showing  luminal changes, the treatment of choice is Enucleation,  but has to be followed up for 5-10 years. In types where  the ameloblastoma infiltrates the adjacent cancellous  bone, marginal resection is the treatment of choice after  initial Enucleation and curettage [51]. This means that  patient has to undergo two surgeries based on the histo-  pathological examination.   There is some controversy on its management, with  some authors advocating aggressive management, espe-  cially for the mural variant, while others advocating con-  servative management such as curettage, peripheral  ostectomy and various adjuvant materials such as Carnoy’s  solution and Liquid Nitrogen [33, 52, 53]. If adequate fol-  low-up is possible, the UA of posterior mandible can be   According to LAU and Samman [54], 30.5%  recurrence rate reported with enucleation alone.    Application of carnoy’s solution along with Enucleation  decrease the recurrence rate to 16% and the least percent-  age of recurrence was seen with resection of tumour, i.e.  only 3.6%    e Stoelinga and Bronkhorst [55] in 1987 suggested the use  of carnoy’s solution for UA as a chemical cauterisation.  The carnoy’s solution consists of chloroform 3 ml, abso-  lute Alcohol 6 ml, | ml glacial acetic acid, sclerosing  agent ferric chloride 1 gm for the management of fistulae  and cysts as a fixative.   ¢ The modified carnoy’s solution avoids the use of chloro-  form due to concerns about its carcinogenicity [56].  However, the recurrence rate is lower with application of  conventional carnoy’s solution after enucleation and curet-  tage in comparison to modified carnoy’s solution [57].   e The use of carnoy’s solution reduces the risk of recur-  rence by fixing the residual tumour tissues after enucle-  ation of UA with mural invasion, but conventional  multicystic ameloblastoma and some UA are unlikely to  be effective by carnoy’s solution. The recurrence experi-  enced more in patients treated with Enucleation alone  without the application of carnoy’s solution.   ¢ The solution is applied for 5 min with the help of cotton  applicator or gauze soaked in carnoy’s solution in the  bony cavity. Irrigation with normal saline is done after    that. The nerve and vessels should be avoided by contact  of the carnoy’s solution as much as possible. The method  and duration of application of carnoy also is contentious  where different regimes have been proposed by various  authors.    Case scenario 3 is provided to show that conservative man-  agement with adjunctive procedures will give reasonably  good results thereby avoiding major resective and recon-  structive surgeries. A 21-year male reported with gradually  growing swelling right side body mandible (Fig. 28.6a).  OPG (Fig. 28.6b) showed an unilocular expansile lesion in  right side body mandible with resoprtion of the associated  roots. There was intra-oral vestibular swelling and it was  fluctuant on palpation due to thinning of the labial cortex. CT  views (Fig. 28.6c-e) show the lesion to be unilocular,  expansile with loss of both labial and lingual cortices. An  incisional biopsy was performed, which gave the report as  Unicystic ameloblastoma. This could be considered as an  aggressive form as there was root resorption. Considering  the age of the patient, a less-radical approach was taken,  which involved excision of the lesion by raising an intra-oral  crevicular mucoperiosteal flap (Fig. 28.6f), extraction of all  the involved teeth (Fig. 28.61), performing a peripheral ostec-  tomy and applying carnoy’s solution (Fig. 28.6g) and also  excising the overlying mucosa, which was in direct contact  with the lesion. The excised cystic lesion was quite thick  walled and an in toto enucleation was possible (Fig. 28.6h).  A reasonable thickness of the lower border of mandible was  left behind and as the alveolar part of labial and lingual cor-  tices was removed, excess tissue was available for achieving  a tension-free primary closure. The postoperative OPG at  one and half years (Fig. 28.6j) shows no evidence of recur-  rence and prosthetic rehabilitation performed. The patient is  recurrence free for past 7 years.    This case scenario is given to show that at times complex  resection and reconstructive procedures may be avoided in  amelobalstomas considering, the patients age and general  health and other social background. In such cases where a  conservative approach is used, the adjunct measures of  peripheral ostectomy and carnoys solution will serve as  adjunct methods to give an overall good prognosis (readers  are also advised to refer chapter 27 on odontogenic cysts  for use of these adjunct measures in odontogenic  keratocyst).   A 67 year old male patient presented with loosening of  teeth and swelling of gums in the anterior mandible    Fig. 28.6 (a) Clinical image showing swelling right body mandible.  (b) opg showing the radiolucent lesion right body mandible with root  resorption. (c) Axial CT image showing the expansile lesion with thin-  ning of the labial cortex. (d) Coronal CT image showing the expansile  nature of the lesion. (e) 3D CT showing the erosion of both labial and  lingual cortical walls. (f) Intra-oral intra-operative view showing the    lesion exposed by crevicular flap. (g) Intra-oral view of the surgical bed  after extraction of teeth, excision of lesion and peripheral ostectomy.  (h) Image of the excised cystic lining, with thick walls. (i) Images of the  extracted teeth showing the root resorption, (j) post operative radio-  graph after prosthetic rehabilitation    Fig. 28.7 (a) loosening of teeth and expansion of the gums in the anterior lower mandible. (b) A OPG and CBCT showing multilocular radiolu-  cency in the anterior mandible. (c) Lesion exposed (d) lesion excised and peripheral ostectomy done (e) carnoys solution applied to surgical bed  (f) sixteen month post operative OPG    (Fig 28.7a). A CBCT scan (Fig 28.7b) confirmed the pres-  ence of a multilocular radiolucency in between right lat-  eral incisor and left first premolar region. An incisional  biopsy confirmed a _ diagnosis of a _ plexiform  ameloblastoma.   Considering the patient’s age and general health, it was  decided to follow a conservative line of treatment to avoid  the need for complex reconstruction.   The lesion was exposed under general anesthesia  (Fig 28.7c) and the involved teeth and tumour lining was    removed. A Large round bur was then used to remove 3mm  of bony walls around the locules left by the lesion (Fig 28.7d).  The lesion was treated with modified carnoy’s solution for 3  minutes (Fig 28.7e) followed by irrigation with normal saline  and primary closure achieved.   Excision pathology confirmed the diagnosis of a Plexiform  ameloblastoma. The healing was uneventful. A 16 month  post operative radiograph showed good bony healing  (Fig 28.7f) without any recurrence and the patient is on long  term follow-up.    The tumour was first described by Kuru [58] 1911. The PA is  defined as the tumour having intra-osseous ameloblastoma  characteristics histologically but occurs in the soft tissues  overlying the tooth-bearing areas of mandible and maxilla.  In comparison to the intra-osseous solid/multicystic amelo-  blastoma, it is the extraosseous counterpart [59].   PA representing only 1—5% of all ameloblastomas consid-  ering it as a very rare odontogenic tumour. It is also called  ameloblastoma of soft tissue, mucosal origin ameloblastoma  and gingival ameloblastoma. It arises from the remnants of  the odontogenic epithelium with in the lamina propria gingi-  val or from the gingival epithelium of the basal cell layer.   It is painless, firm and exophytic growth with a smooth,  granular and warty surface. Most commonly located in the  oral mucosa or the gingiva. It occurs in wide age range groups,  i.e. from | to 92 years with more than 64% of cases occurring  in the fifth to seventh decade of life. In edentulous areas, it  affects the alveolar mucosa. The ratio of 2.4:1 is noted in man-  dible: maxilla. Intra-osseous ameloblastoma rarely extends to  the gingival tissues and merge with gingival epithelium creat-  ing PA of the exophytic type [60]. Histopathologically same  histomorphic cell types of odontogenic epithelium seen in  solid/multicystic variant as consist in PA.    It does not show invasive behaviour and the treatment of  choice will be conservative excision with adequate disease-  free margins. The recurrence is low, but patients are to be  kept on long-term follow-up.    ‘Malignant Ameloblastoma (MA)’ term was proposed by  Slootweg and Muller [61] in 1984. According to them, it is  well-differentiated ameloblastoma that metastasises but  which maintains the characteristic cytologic features of orig-  inal tumour [62]. The ameloblastic tumour that undergoes  malignant cytologic transformation; the term ‘Ameloblastic  carcinoma’ is used.   Metastasis is the only factor that distinguishes ameloblas-  toma from MA. Its clinical behaviour is helpful in diagnos-  ing the tumour.   Lung shows maximum 75% metastatic deposits, 15%  each by spine and cervical lymph nodes followed by    cervical lymph nodes and spine (15% each) [63]. Small  bowel, liver, skull, brain and kidneys were the other  locations, which show metastases but with lower inci-  dence [64].   MA is very rare with an occurrence rate of 2% of all  benign ameloblastomas [65]. The age ranges from 5 years  to 74 with 34.4 years mean age. 1:1.2 is the male to  female ratio. The majority cases were localised in the  mandible. The survival time ranges from 3 months to 5  years after the appearance of metastases. Most MA are  histologically plexifom type but not significantly differ-  ent from the metastatic type in their histologic and cyto-  logic features [66].   The initial tumours were treated with Enucleation and  curettage while advanced with resection (block or segmen-  tal). Open thoracotomy is indicated in discrete and isolated  lung metastases and wedge resection. Occasionally, chemo-  therapy gives successful results. Inoperable metastatic  deposits can be treated with radiation therapy but having an  unpredictable response [67, 68].    Squamous odontogenic tumour (SOT) was first described by  Pullon et al. [69] as a rare benign odontogenic tumour in 1975.  It affects all the age group and equally occurs in both the jaws.  SOT histologically characterised by squamous epithelial  islands, which are surrounded by mature connective tissue  stroma. The SOT is occasionally misdiagnosed as squamous  cell carcinoma, keratocanthoma, ameloblastoma and verrucous  carcinoma. It is hamartomatous epithelial proliferation, arising  probably from cell rests of Malessez [70]. The differential  diagnosis of SOT may be acanthomatous and desmoplastic  ameloblastoma variants, squamous cell carcinoma (well  differentiated).    “SOT is a locally infiltrative, benign neoplasm consisting of  islands of well-differentiated squamous epithelium in a  fibrous stroma. The epithelial islands shows foci of central  cystic degeneration occasionally” (WHO).   . Occurs in the mean age of 38 years with age ranges from  8 to 74 years.    5. Multiple SOT, which involves several quadrant of mouth  in few patients have been reported, a family of 3 siblings  having multiple lesions has been reported.   6. Absence of periodontal ligament between the lesion &  the root of the tooth, suggesting that lesion arises from  Malassez rests cell in the periodontal ligament or closely  adjacent mucous membrane.   7. Equally affects maxilla and mandible, but most commonly  involves incisor-cuspid area in maxilla and bicuspid-  molar area in mandible    1. Unilocular radiolucency of the triangular or semicircular  type located in alveolar bone along the roots’ lateral  surface.   4. Sometimes, tumour appears as an intra-bony pocket  between the teeth   5. Peripheral lesions may cause saucerisation of underlying  bone, which is likely because of the pressure phenome-  non rather than infiltration of the tumour.   6. Few extensive lesions show multilocular radiolucency,  pushing the maxillary sinus and involving the mandibular  body region.    Conservative treatment in the form of local excision, enucle-  ation and curettage may be done for the successful manage-  ment of SOT. Recurrent and clinically aggressive lesions  have been treated with en bloc excision. Extraction of the  associated teeth along with the conservative treatment is  mandatory. It has a very low recurrence rate [73].   Cortical bone erosion of maxilla and mandible  exhibits aggressive biological behaviour. Aggressive treat-  ment should be followed for the lesions, which show early  recurrence [74].    Pindborg in 1955 first introduced the calcifying epithelial  odontogenic tumour (CEOT) in the scientific literature [75].  It is well known as ‘Pindborg Tumor’ since then. CEOT is  slow growing, benign and occasional locally invasive odon-  togenic neoplasm, which is epithelial in its origin.   WHO accepted and adopted the term calcifying epithelial  odontogenic tumour (CEOT) in its first edition of  ‘Histological typing odontogenic tumours, jaw cysts and    allied lesions’, and recognised it as a distinct entity [76]. It  may be extra-osseous or intra-osseous.    CEOT is a epithelial odontogenic neoplasm, which is locally  invasive and is characterised by the presence of amyloid  material that may become calcified (WHO)    It accounts for less than 1% of all odontogenic tumours,  hence considered uncommon. It commonly occurs between  the age of 8 and 92 years with the mean age of 36.9 years.  The intra-osseous variant occurs in the third, fourth and  fifth decade of life in 64% of patients [77]. CEOT has no  gender predilection, and occurs equally in both the sexes.  Premolar and molar regions are the commonest site of occur-  rence, although can occur at any site. Anterior gingiva is most  commonly affected by the peripheral lesions. Maximum  cases reported are of intra-osseous lesions, only 6% arise in  extra-osseous locations. Mandible is affected by intra-osseous  lesions more frequently than maxilla, with a ratio of 2:1.    CEOT is slowly growing, painless, expansile and hard bony  swelling, which can cause thinning of the cortical bone and  infiltration of soft tissue subsequently. It can cause rotation,  tipping, migration or mobility of tooth secondary to resorp-  tion of roots. In the anterior region, there is also a distinctly  uncommon peripheral variant of CEOT, limited to soft tissue  only, presenting as a nodular mass on the gingiva.    The larger or the mature tumour will be mixed radiolucent—  radiopaque, although the early tumour may be completely  radiolucent. CEOT is often associated with unerupted teeth. It  may be unilocular and cystic in appearance. It can demonstrate  a mixture of large and small multilocular spaces described as  ‘soap bubble’ and ‘honey comb’ in appearance. The radio-  graphic borders in almost all cases between surrounding tissues  and tumour appear to be circumscribed and well defined [78].   CEOT on CT examination demonstrating thinning and  expansion of lingual and buccal cortical plates with well-  defined mass containing scattered radiopaque areas of  different size and signal intensity in mandible. Pindborg  tumour on MRI reveals predominantly a hypointense lesion  on Tl-weighted images and mixed hyperintense lesion on  T2-weighted images [79].    Surgical management is the treatment of choice for  CEOT. Conservative treatment in the form of Enucleation or  curettage followed by judicious removal of the thin layer of  bone adjacent to the tumour is the choice of treatment in  small, intra-bony lesions with well-defined borders. However,  the tumours treated with curettage and enucleation show a  recurrence rate ranging from 15 to 30% after 2-4 years with  the overall recurrence rate of 14% [77].   According to Melrose RJ [80], even the small CEOTs are  infiltrating in nature. A margin of about 1 cm normal bone  should be removed along with the tumour excision. Peripheral  tumours are treated with smaller margins 0.5 cm because  they are less aggressive. Few recurrences have been reported  with the tumours treated with jaw resection. However, the  patient should be kept for follow-up upto 5—10 years.   The recurrent lesions and the tumours, which are diagnosed  late in their clinical course, which over an extended time  becomes larger and extensive (more than 4 cm in size) may not  respond well to conservative management-like surgical exci-  sion only. Segmental resection such as partial or hemiman-  dibulectomy or hemimaxillectomy will be the treatment of  choice. However, it may leave a significant bony discontinuity  requiring grafting or extensive soft tissue reconstruction.   The incidence of malignant transformation is very low;  however, Veness et al. [81] reported a case of metastatic  spread and malignant transformation with CEOT.    Stafne in 1948, first described the adenomatoid odontogenic  tumour (AOT) as an odontogenic neoplasm [82]. It was  referred as ameloblastic adenomatoid tumour or adenoamelo-  blastoma initially, because it was considered as a variant of  ameloblastoma [83]. The term AOT, which is generally  accepted today suggested by Philipsen and Birn [84].    A neoplasm of locally invasive nature was characterised by  ameloblastoma-like islands of epithelial cells in a mature  connective tissue stroma. Aberrant keratinisation may be  found in the form of ghost cells in association with varying  amounts of dysplastic dentin (WHO).   Three variants of AOT are recognised, i.e. Follicular,  Extra follicular and peripheral.   The peripheral type arises from the gingival tissues and  is very rare. The follicular type is commonly associated  with impacted tooth and found in 75% of cases; on the  other hand, the extrafollicular type is located between the  roots of adjacent teeth and is not related to an unerupted  teeth [86].    ¢ AOT commonly occurs in the anterior region of jaws, par-  ticularly the maxilla.   e Jt occurs commonly in young patients, two-thirds of the  cases occurring between 10 and 19 years of age. However,  the age ranges from 3 to 82 years [87].   e Females are affected more than males with a ratio of 5.6:1.   e Size of AOT ranges from 2 to 7 cm with more than 60%  involving the entire quadrant [88].   ¢ The most common tooth associated with AOT is impacted  canine followed by premolars and lateral incisors [89].    Radiographically, the most common appearance will be a  well-demarcated unilocular radiolucency associated with  unerupted tooth. Sometimes, intra-bony cases show scat-  tered radiopacities within the radiolucency. Intra-oral peri-  apical radiographs found to be better than OPG are best  suited for showing discrete calcified deposits [90].   The AOT is usually well-encapsulated tumour so the  treatment of choice will be Enucleation and Curettage. The  recurrence is extremely rare [91].    Ameloblastic Fibroma (AF) was first reported by Kruse in 1891  [92]. AF consists of odontogenic ecto-mesenchyme resembling  the dental papilla, epithelial strands and nests resembling dental  lamina and enamel organ. Dental hard tissues are absent in it.  The lesion is referred to as ameloblastic fibro-dentinoma if there  is dentin formation. It is a rare odontogenic mixed tumour in  which ectomesenchymal and epithelial elements are neoplastic.  It accounts only 2% of all odontogenic tumours [93].   AF occurs in young adults and children with an age range  from 1.5 to 42 years, with the average age ranging from 14.5  to 15.5 years [94]. It was occasionally reported in middle-  aged individuals. There is no gender predilection. More than  50% of patients present with a sign of swelling. Failure of  tooth eruption, pain, tenderness and discharge are the other  common findings [95]. Posterior mandible is the common-  est site of occurrence and first permanent molar and second  primary molar areas were involved in more than 70% of  cases.   Multilocular radiolucency with sclerotic margins is the most  common radiographic appearance. Unilocular radilolucency  is the feature of small tumours, while large tumours extend  through the bony cortices. The size typically ranges from 1    to 8 cm [96]. Ameloblastic fibrosarcoma is the differential  diagnosis of AF.   Enucleation and curettage of the adjacent bone along with  the extraction of affected teeth is the treatment of choice for  AF. They occur rarely but required a long-term followup. In  order to preserve the teeth involved in the tumour, the chances  of recurrence increase after conservative management [97, 98].   The ameloblastic fibro-odontoma is composed of connec-  tive tissue characteristic of an ameloblastic fibroma and cal-  cified tissue identifying the tumour as a complex odontoma.  The ameloblastic fibro-odontoma diagnosis is based on the  histologic evidence of ameloblastic fibroma with active  odontogenic epithelium embedded in an embryonal connec-  tive tissue. The differential diagnosis of ameloblastic fibroma  and ameloblastic fibro-odontoma is based on the absence  (ameloblastic fibroma) and presence (ameloblastic fibro-  odontoma) of enamel and dentin. A tumour is called amelo-  blastic fibro-dentinoma when exclusive dentin formation is  observed. A tumour is called an ameloblastic fibro-odontoma  in the presence of both enamel and dentin. In ameloblastic  fibroma, no dental hard tissues are present [99]. AFO is simi-  lar to AF described by the WHO, and [they also show induc-  tive changes that lead to both enamel and dentin formations].  Moreover, AFO and AF are defined as hamartomatous  lesions and they are believed to be stages of formation of  odontoma. That means the above-mentioned lesions should  not be considered as distinct entities [100].    In 1866, Broca coined the term ‘Odontome’ [101]. The term  ‘Odontoma’ was given by Thoma and Goldman, to include  tumours that were composed of well-differentiated tooth  structure [102]. Odontoma defined as a tumour that differen-  tiated and developed enough to produce dentin, enamel and  cementum in varying proportions [103].   Compound odontoma is defined by the WHO as a malfor-  mation in which all the dental tissues represented in a more  orderly pattern than complex odontoma, so that lesions con-  sist of many tooth-like structures.   Complex odontoma is a type of malformation in which all  dental tissues are represented and individual tissues are well  formed, but occur in a disorderly pattern [104].   Compound-type odontomas are more common than com-  plex odontomas [105]. According to Regezi, the compound  odontomas are 37% and complex odontomas were 30% of  all the reported odontogenic tumours [106]. Odontomas  occur equally in both sexes. They are rarely associated with  deciduous teeth but more frequently associated with perma-  nent teeth. Anterior maxilla is the most common site for the  occurrence of compound-type odontome while posterior  mandible (Fig. 28.8) is affected more commonly in complex  odontomes followed by anterior maxilla [107].    They are small, painless and hard mass. Permanent  impacted or retained deciduous teeth are present as a com-  mon symptom. The second most common complaint is  swelling. Complex odontoma may become large and pro-  duce asymmetry with bone expansion [108, 109].   On radiological examination, the lesion consists of  densely opaque masses of varying size, usually associ-  ated with unerupted or impacted teeth. The radiolucent  line surrounds the opaque masses. The collections of  tooth-like structures of different shapes and sizes are the  features of compound odontomes, the teeth are of dimin-  utive sizes. The complex-type odontomes appear as calci-  fied masses that have consistency the same as the tooth  structure.   The treatment of choice for odontomes is surgical exci-  sion and recurrence is very rare.   Myxoma is very uncommon. It accounts for 0.5 to 20% of all  odontogenic tumours and has a incidence of 0.07/million  [110]. It arises from mesenchymal stroma and is a benign,  locally aggressive tumour. Bone, soft tissues and most fre-  quently the myocardium are favourite sites for myxomas.  Jaws myxomas are both odontogenic and osseous in the ori-  gin . Myxoma according to WHO is defined as a locally inva-  sive neoplasm, consisting of angular and rounded cells that  lie in an abundant mucoid stroma [111].    28.14.1.1 Clinical Features  The myxomas have a predilection for molar and premolar  regions of mandible and maxilla, however they can occur    anywhere in the jaws. One third of myxomas located in the  maxilla while two third in mandible. In maxillary myxomas,  the cortical expansion and perforation of bone are common  and often extend into the sinus [112].   It is reported to have a slight female predilection  (1.5:1) while other authors reported equal gender predi-  lection between females and males. Odontogenic myxo-  mas most commonly occur in the second and third  decade of life with the average age ranging from 25 to 30  years [113].   The periapical radiographs and OPGs are the first indica-  tors of myxomas of jaws. Odontogenic myxomas radio-  graphically present as unilocular lesions to large multilocular  neoplasms, which often cause displacement of teeth but  resorb the roots less frequently. The unilocular lesions are  small in size on the other hand multilocular myxomas are  greater than 4 cm in size. 5% Myxomas have association  with unerupted tooth [114].   Surgical excision is the treatment of choice of odontogenic  myxomas. The rate of recurrence is quite high, i.e. nearly  25% during first two years after removal. Atleast | cm of  medullary bone should be resected along with tumour and  always try to involve one tumour-free anatomic barrier at its  periphery [78]. Subramaniam S [115] used endoscopes in the  resection of pterygoid plates for the complete treatment of  odontogenic myxoma. Use of endoscopes eliminates the use  of extra-oral incisions.    Dewy in 1927 first described Benign cementoblastoma  [116]. It is a rare tumour of mesenchymal origin. Cementum-  like tissue formation around the roots of the teeth is its  important characteristic.   Cementoblastoma has predilection of mandible with  79.5% and most commonly in the premolar and molar region.  They rarely occur in maxilla.   The roots of vital erupted permanent tooth are affected by  the cementoblastoma. The most common tooth involved is  the mandibular first molar. It has slight male predilection and  occurs most commonly in the second and third decade of  life. Cementoblastoma can cause teeth displacement, expan-  sion of bone and maxillary sinus invasiveness, and aggres-  sive tumours usually present with the symptoms of swelling  and pain [117].   The diagnosis of cementoblastoma is very challenging  as hypercementosis is also associated with roots of the  teeth, that is the reason why hypercementosis is always  included in the differential diagnosis. Cementoblastoma  is slow growing, but can cause perforation and expansion  of the cortices. The most common symptom is pain [118].  Radiographically the lesion will appear as a radiopaque    mass fused with roots of the teeth , surrounded and lim-  ited peripherally by a radiolucent halo.   Complete excision of cementoblastoma is the gold stan-  dard treatment with extraction of the involved teeth [119]. It  must be removed early, otherwise it may continue to grow.  Maxillary lesions at times can involve the entire maxillary  sinus making the prognosis poor. Recurrence is very rare,  however incomplete removal may result in recurrence.   The tooth associated with cementoblastoma may be pre-  served under the following conditions [120]   2. In asymptomatic patients, with no pain  3. Perforation of cortical plates is absent  4. Patient refusal for teeth extraction    Genetic marking has helped identify gene mutations, which  may in the future help with histological and clinical manage-  ment of these lesions. The most promising of these is the  BRAF V600E mutation that is present in 90% of ameloblas-  tomas and in the unicystic mural variant, suggesting predis-  position to infiltrative behaviour. In the future, gene therapy  may be possible using this gene marker [121].   The sonic hedgehog (SHH) and PI3K/Akt/Mtor signaling  pathways may soon provide non-surgical options for treat-  ment of ameloblastoma. The tumours that depend on active  SHH signalling for growth/survival and maintenance may be  susceptible targets for combined chemotherapy with SHH-  specific inhibitors together with PI3K, Akt or mTOR block-  ing agents [122]. Jaamb T and Kramer JM advise to check  molecular markers and accordingly decide the treatment  plan [123]. Effiom OA et al. reported that explanation of  molecular factors that arrange pathogenesis and recurrence  of ameloblastoma will lead to new targeted drug therapies  and diagnostic markers for ameloblastoma [124].    A 25 year old male patient presented with an expanding  lesion around the left upper posterior teeth (Fig. 28.9a).  Radiographs suggested a cystic lesion and a CT scan con-  firmed bony destruction by a multilocular lesion extending  from the first molar to the tuberosity (Fig. 29.8b). An inci-  sional biopsy of the lesion confirmed a diagnosis of follicular  ameloblastoma.   The patient had excision of the lesion with a posterior par-  tial maxillectomy, with a mandibular split [125] for access  (Fig. 28.9c, d). The defect was reconstructed with a tempora-  lis muscle flap (Fig. 28.9e, f, g). The mandibulotomy site was  fixed with titanium plates (Fig. 28.9h).    Fig. 28.9 (a) expanding lesion around the left upper posterior teeth.  (b) CT scan confirmed bony destruction by a multilocular lesion  extending from the first molar to the tuberosity. (c) Incision marked for  partial maxillectomy via mandibular split access (d) left posterior par-  tial maxillectomy being performed (e) temporalis muscle flap being    harvested (f) temporalis flap being advanced to the partial maxillec-  tomy defect (g) Introperative view after suturing of the temporalis flap  to cover the defect. (h) Fixation done at the mandible split region (i)  post-operative intra oral view showing good healing (j) extra oral view  showing good cosmetic and functional result    The healing was uneventful. Pathology reports confirmed  the diagnosis of Follicular Ameloblastoma with clear exci-  sion margins. He had an excellent intra oral and cosmetic  (extra oral) post-operative result (Fig. 28.91, j).   Maxillectomy through mandibulotomy approach has  been followed by author in a series of cases [125].   The readers are advised to refer chapter 85 of this book  for detailed reading on access surgeries and osteotomies for  the maxillofacial region.    Posterior mandible and cuspid areas of maxilla are the most  common sites for the odontogenic tumours to occur.  However, they can occur anywhere in the tooth-forming  apparatus. The detailed history, thorough radiological and  clinical evaluation is important in making the probable diag-  nosis. Conservative and aggressive surgical management  has been used according to the size and extent of the tumour.    Proper aesthetic reconstruction should be carried out to  avoid facial disfigurement. To check for recurrence, patients  should be kept on regular follow-up and ensure long-term  successful results.    Acknowledgements for Figs. 28.4 and 28.6 (case scenarios 2 and 3) to  suvy manuel    Classification. Head and neck tumors. In: Odontogenic tumors.  Lycon: IRAC Press; 2005. p. 283-318.    . Wright JM, Soluk TM. Odontogenic tumors: where are we in    . Gorlin RJ, Pindborg JJ, Clausen FP, et al. 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Br J Oral Maxillofac Surg.  2016;54(9):1001—5.   Soluk-Tekkesin M, Wright JM. The World Health organization clas-  sification of odontogenic lesions: a summary of the changes of the  2017 (4th) edition. Turk Patoloji Derg. 2018;34(1):1-18.   Troiano G, et al. Conservative vs radical approach for the treatment  of solid/multicystic ameloblastoma: a systematic review and meta-  analysis of the last decade. Oral Health Prev Dent. 2017;15(5):421-6.    Open Access This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.  org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropri-  ate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.   The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in  a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.   The tissues of the oral and maxillofacial region are con-  stantly exposed to a plethora of inflammatory stimuli that  can be of bacterial, physical, chemical or immunologic in  the origin. Chronic/long-standing, low-grade inflammatory  stimuli can induce a heightened/escalated reparative response  in the oral tissues resulting in the occurrence of non-  neoplastic, hyperplastic lesions that are collectively referred  to as reactive lesions [1].   Though the occurrence of exophytic reactive proliferation  in the oral cavity is relatively common, certain malignant  (metastatic/primary) and benign tumours, vascular lesions  can closely mimic these lesions leading the clinician to mis-  diagnosis and sub-optimal treatment. A thorough under-  standing of the clinical presentation, differential diagnosis  and the required diagnostic workup is the key to appropriate  treatment.    ¢ Pearls, Perils & Pitfalls  e Case Scenarios  ¢ Recent Advances    These lesions can be peripheral/extra-osseous (Soft tissues-  Gingiva, oral mucosa etc.) or Central (intra-osseous) in  occurrence.    R. S. Gali   Department of Oral and Maxillofacial Surgery, Narayana Dental  College and Hospital, Nellore, Andhra Pradesh, India    © The Association of Oral and Maxillofacial Surgeons of India 2021    Eversole classified the common peripheral hyperplas-  tic lesions of gingiva and other oral mucosal sites into  the following categories [2, 3].    The intra-osseous reactive lesions include the follow-  ing categories [4, 5].    Pyogenic Granuloma presents as a painless pedunculated or  sessile, soft fleshy mass that bleeds easily with a normal or  occasionally ulcerated overlying surface (Fig. 29.1). Gingiva  is the most common intra-oral site, although it can affect lips,  mucosa and tongue [3].   It is a localised proliferative mass occurring as a result  of an exuberant reparative response to various stimuli such  as chronic local irritation (calculus, overhanging restora-  tion, a sharp margin of crown etc.), trauma, hormonal  changes (Pregnancy), bone marrow transplants and reac-    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1-15-1346-6_29    Fig. 29.1 Exophytic gingival growth associated with chronic gingivi-  tis with heavy bands of calculus. The lesion easily bleeds on palpation  and can occasionally cause displacement of teeth    tion to grafts. Pulp polyp or hyperplastic pulpitis is also a  type of pyogenic granuloma arising in response to low-  grade chronic infection [1]. The term pyogenic granuloma  is a misnomer as it does not contain pus and it is not a true  granuloma [1, 3].   It can occur across all the age groups and both genders,  but with a distinct predominance in females in the 2nd decade  of life due to the increased levels of circulating hormones  like oestrogen and progesterone [6]. Equal incidence has  been reported in both the jaws with a slight predilection to  anterior maxilla [1].    Other peripheral reactive lesions that resemble pyogenic  granuloma are peripheral giant cell granuloma and periph-  eral ossifying fibroma [3]. Peripheral ossifying fibroma has  a firm consistency and a lesser tendency to bleed. Specific  proliferative malignant lesions can closely mimic pyogenic  granuloma misguiding the clinician leading to sub-optimal  treatment. These can be primary or metastatic squamous  cell carcinomas, fibrosarcoma, Kaposi’s sarcoma, oral met-  astatic deposits from distant primary foci like thyroid, lung  kidneys etc [1].    Radiological Features Appreciable radiological changes  are generally not seen in pyogenic granuloma, but occasion-    ally cup-like resorption of underlying alveolar bone can be  seen in a peri-apical view or an orthopantomogram. Ruling  out the presence of large osteolytic lesions is required to  exclude malignant lesions.    Histopathological Features Histologically pyogenic granu-  lomas are classified into two distinct sub-types- the non-  lobular capillary haemangioma type (non-LCH type) and  Lobular capillary haemangioma (LCH) type [6]. The non-  LCH type comprises of highly vascular proliferation that is  similar to granulation tissue with foci of fibrous tissue  whereas the LCH type shows proliferation of blood vessels  that are aggregated in a lobular fashion without any signs of  inflammation and or reparative response.    Epivatianos A et al. had demonstrated that these two sub-  types have a different origin, clinical behaviour and immu-  nohistochemical properties [7]. Their study had shown that  non-LCH pyogenic granuloma presented clinically as a  pedunculated mass and was mostly associated with identifi-  able aetiologic factors and showed a histological picture of a  reparative response. However, LCH pyogenic granuloma  presented as a non-ulcerated sessile mass without any identi-  fiable aetiology and histological evidence of lobulated vessel  pattern and the absence of inflammatory reaction. This has  led to the concept that LCH pyogenic granuloma represents  a benign tumour of the vascular origin that develops due to  unknown factors just like other benign tumours.    Surgical excision of the lesion followed by removal of local  irritants such as calculus, foreign body etc. is the standard  treatment. Excision up to the periosteum is required in gingi-  val lesions followed by either primary closure by mobilisa-  tion of adjacent mucoperiosteum, or surgical defect is left to  heal by secondary intention by the placement of Coe pack.  Brisk bleeding is often encountered during excision that  would require electrocoagulation. Other treatment options  include electrocautery, cryosurgery, sclerotherapy and laser-  assisted excision.    removal of local aetiological factors will eliminate the  chances of recurrence.    Peripheral giant cell granuloma is the most commonly  encountered giant cell containing lesion of the oral cavity  that closely resembles pyogenic granuloma.    It is thought to originate mainly from the connective tis-  sue of the gingiva or the periosteum of the alveolar ridge.  It has been reported in all age groups but with a peak inci-  dence in the 3rd and 4th decades of life with a female  predominance [8]. The lesion presents as a soft prolifera-  tive mass occurring at gingiva or even at edentulous alve-  olar ridge. It has a tendency to bleed and may or may not  be pedunculated [9].   The term ‘reparative’ was dropped from its nomenclature  as the reparative nature could not be demonstrated histopath-  ologically. The aetiology of this lesion remains unclear, but  irritating local factors such as poor restorations, prostheses  calculus etc. are thought to contribute to its origin (Fig. 29.2).    Clinically pyogenic granuloma and peripheral giant cell  granuloma are indistinguishable. Erosion of cortical bone is  more commonly seen with peripheral giant cell granuloma  than with pyogenic granuloma.   Histopathologically, the lesion is very similar to central  giant cell granuloma, its intra-osseous counterpart [9].    Since the lesion is peripheral in the origin and location,  radiologic changes are rarely seen. Longstanding, larger  lesions can exhibit superficial cortical erosion and may also  show widening of adjacent periodontal ligament space.    Hyperplasia of fibroblasts with abundant multi-nucleated  giant cells, with scattered areas of chronic inflammatory  cells and neutrophils are seen [9]. Controversy exists  about the origin of the giant cells; some believe that they  are of the osteoclast origin while others state that they are  formed by the fusion of mono-nuclear cells. Irrespective  of their origin, they are non-functional in these lesions as  they are not involved either in phagocytosis or bone  resorption [9].    Fig. 29.2 Peripheral giant cell granuloma, presenting as an exophytic  gingival growth firm to hard in consistency causing displacement of  adjacent teeth    Complete surgical excision including the periosteum or peri-  odontal ligament as applicable followed by the removal of  local factors is the optimum treatment for peripheral giant  cell granuloma. Recurrences are rare, but have been reported  and are believed to be due to non-inclusion of periosteum or  periodontal ligament during excision.    Recurrence of PGCG is infrequent, ranges as little as 5—11%  have been reported. Extensive clearing of the base of the  lesion, eradication of the source of irritation prevents recur-  rence [9].    Increasing incidence of peripheral giant cell granulomas  occurring in association with dental implants has been  reported [10, 11]. Local irritant factors, inflammation of    peri-implant tissues are the causative factors. Clinically,  these proliferations are similar to the classic peripheral  giant cell granulomas and usually develop within months  to years following placement of dental implants. If early  detection and complete surgical excision are not per-  formed, such lesions can lead to peri-implantitis, ulti-  mately leading to failure of the implant necessitating its  removal.    The peripheral ossifying fibroma is a reactive gingival  proliferation presenting as nodular mass firm in consis-  tency with or without ulceration. It contains fibroblastic  cellular tissue with varying amounts of mineralised con-  tent that can be either bone, cementum or dystrophic  calcification.   The term ‘peripheral ossifying fibroma’ literally means a  benign tumour of fibrous connective tissue origin. However,  this lesion is a non-neoplastic reactive proliferative lesion, so  this term is a misnomer for this pathology [12].    The lesion presents as a slow-growing solitary gingival  growth commonly seen during the second decade of life,  predominantly in women in the anterior region of either of  the jaws. The lesion is believed to originate from peri-  odontal ligament in response to local irritation or inflam-  mation, commonly seen at the inter-dental region as a  pedunculated or sessile mass (Fig. 29.3). The exact patho-  genesis of peripheral ossifying fibroma is controversial.  Some authors believe that it initially develops as a pyo-  genic granuloma that subsequently undergoes fibrous  maturation and calcification. It is thought that these two  lesions represent progressive stages of the same reactive  pathology [13].   Histopathology is the only method by which one can distin-  guish a peripheral ossifying fibroma from a pyogenic granu-  loma or peripheral giant cell granuloma [14].    Fig. 29.3 Exophytic sessile mass over gingiva at anterior maxilla asso-  ciated with heavy bands of calculus and is seen to be causing displace-  ment of teeth    The peripheral ossifying fibroma consists of rich fibro-cellu-  lar tissue with focal areas of mineralised deposits containing  bone, cementum or dystrophic calcification. A chronic  inflammatory cell infiltrate is observed at the periphery of  the lesion.    Complete surgical excision of the lesion with circumferential  margins of 3mm of healthy gingival tissue and deep margins  down to the bone, including the adjacent periosteum and  periodontal ligament has to be performed to reduce the  chances of recurrence [1]. Extraction of the involved teeth is  to be considered in the cases of recurrent or multi-focal  lesions of peripheral ossifying fibromas.    fibroma is surprisingly high for a reactive proliferation. The  recurrence rate has varied from 4 to 75% [15, 16].    Fig. 29.4 (a) Large peripheral ossifying fibroma of 6 x 7 cm in size, in  a 64-year-old female, 5 years duration presenting as firm mass. (b)  Radio-opacities on the radiograph observed in the excised lesion. (c)  Histopathological view showing the woven bone (H&E stain, original    magnification 400x). (Adapted from A rare massive exophytic gingival  growth: Suvy Manuel et al.; Clinics and Practice. 2012 Mar 30; 2(2):  e38. Open Access DOT https://doi.org/10.408 1/cp.2012.e38 , copy right  S. Manuel et al, CC BY-NC 3.0, Licensee PAGEPress Italy)    1. The most common proliferative masses of Gingiva  are a Triad of reactive lesions—The 3 P’s—  Pyogenic Granuloma, Peripheral giant Cell granu-  loma & Peripheral Ossifying fibroma.   2. Pyogenic granulomas and peripheral giant cell  granulomas are more vascular, which is reflected by  their tendency to bleed and their red or reddish-blue  colour.   3. Unlike pyogenic granuloma, peripheral giant cell  granuloma can occur on edentulous alveolar ridges  arising from the periosteum   5. Complete Surgical excision of these lesions with  circumferential margins of 3 mm of healthy gingi-  val tissue and deep margins down to the bone,  including the adjacent periosteum & periodontal  ligament has to be performed to reduce the chances  of recurrence. This should be followed by removal  of putative local factors like calculus, plaque faulty  restoration/prosthesis etc.   6. Extraction of the involved but firm teeth should be  considered in the cases of recurrent/multi focal  lesions.    Synonyms Central giant cell Lesion, Central reparative giant  cell granuloma and Giant cell tumour of jaw bones.    The central giant cell granuloma is one of the few maxillofa-  cial pathologies that have generated a significant amount of  discussion and controversy. The true biological nature of the  lesion remains to be understood and the debate about label-  ling it as a tumour still exists [12].   Initially, it was described as Giant cell ‘reparative’ granu-  loma by Jaffe in 1953 [17] suggesting that it was a reactive  response to intra-bony haemorrhage and inflammation.  Later, the term ‘reparative’ was dropped, as prior traumatic/  inflammatory episodes could not be elicited in most cases  and clinical progression of disease was inconsistent with the  repair process of bone.    The aggressive clinical behaviour of specific lesions dem-  onstrated by osteolysis, cortical expansion, perforation and  extension into soft tissue has led to the view that it is a benign  tumour similar to the giant cell tumour of long bones [18].  The exact relationship between these two pathologies  remains to be understood. The concept that these lesions rep-  resent two points in the spectrum of a single-disease process  has been putforth [19, 20]. Considering the variability in  clinical presentation, individual authors have classified it as  a rapidly growing & destructive—aggressive form and a  slow-growing, incidentally picked up lesion—the non-  aggressive form [19, 20].   Since the true neoplastic nature is yet to be established  and the histologic features do not represent a true granulo-  matous lesion, the term central giant cell ‘lesion’ had been  proposed by Whitaker & Waldron [20].    The lesion can occur in any age group but, children and  young adults are more commonly affected and with a female  predominance [19]. The anterior mandibular region is the  most frequent site of occurrence almost twice as compared to  the maxilla. The most common presentation is that of an  asymptomatic, slow-growing, bony hard and expansile  swelling of the involved jaw [19, 20]. This can be accompa-  nied by progressive displacement/loosening of teeth, pares-  thesia, nasal obstruction and secondary infection leading to  pain (Fig. 29.5a, b).    Histopathologically, central giant cell granulomas and brown  tumour of hyperparathyroidism are indistinguishable from  each other, and this can be very misguiding to the clinician  and the pathologist. Hence, biochemical tests like serum cal-  cium, phosphate and parathormone levels are to be evaluated  to rule out brown’s tumour. In all cases of multi-focal and or  recurrent central giant cell granulomas of jaws, the possibil-  ity of primary or secondary hyperparathyroidism is to be  ruled out, so that unnecessary surgical procedures and their  added morbidity can be avoided.    The central giant cell granuloma presents as multi-locular  radiolucency with scalloped margins that are usually non-  corticated [19]. The cortical expansion, thinning followed by  perforation, root resorption and displacement of adjacent  teeth can be seen in aggressive variants [20] (Fig. 29.5c, d).    Fig. 29.5 (a, b) Central Giant cell granuloma presenting as hard bony  mass over the left body of the mandible with bi-cortical expansion. (c)  Central Giant cell granuloma presenting as a unilocular osteolytic    The lesion consists of a proliferation of spindle-shaped fibro-  blasts in fibrous and fibromyxoid/vascular stroma [20].  Clusters of multi-nucleated giant cells are scattered through-  out connective tissue stroma especially around vascular  channels. These cells are believed to originate from osteo-  clasts or by the fusion of mono-nuclear cells [9]. Focal  deposits of metaplastic bone are seen. The histological pic-  ture is precisely identical to brown’s tumour of hyperpara-  thyroidism [1].    The most commonly practised and favoured treatment for  central giant cell granuloma has been aggressive surgical    lesion with sclerotic border and thinning of lower border. (d) Occlusal  radiograph demonstrating bi-cortical expansile lytic lesion with incom-  plete septae    curettage. Recurrence rates ranging from 20 to 50% have  been reported following curettage [21]. Adjuvant treat-  ments to curettage-like peripheral ostectomy or marginal  resection have been advocated to reduce the chances of  recurrence [22]. Aggressive surgical treatment options  such as en bloc resection/segmental mandibulectomy/  maxillectomy are presently reserved for locally advanced  lesions & recurrent lesions [22, 23]. Significant vascular-  ity and intra-operative bleeding are frequently associated  with these lesions. Aggressive surgical resection with  0.5 cm margins of healthy tissue is advocated to reduce  the chances of recurrence [24]. However, the morbidity  associated with surgical resection such as functional, cos-  metic impairment, loss of teeth, teeth buds and neurosen-  sory disturbances questions the need for such aggressive  treatments in a benign reactive lesion-like central giant  cell granuloma [24].    Fig. 29.6 (a) Swelling right side face. (b) Intra oral view of lesion right posterior maxilla. (ec) CT axial cut showing changes in posterior right    Medical Methods of Treatment Based on the premise that  osteoclastic activity steers the progression of the disease pro-  cess, medical treatments aimed at antagonising the activity  and proliferation of osteoclasts have been used with varying  rates of success [25-27].    Intra-lesional Steroids Steroids have demonstrated the  ability to inhibit bone resorption and induce apoptosis of  osteoclasts. Weekly intra-lesional injections of triam-  cinolone acetonide for six weeks have shown highly  variable results from partial shrinkage, in complete  remission, to complete resolution leading to hypercalci-  fication of the area [28, 29]. The protocol described  involves the use of a 50% mixture of local anaesthetic    and 10 mg/ml triamcinolone acetonide. Two ml of this  solution has to be used for every Icc of the lesion visible  on orthopantomogram [29, 30].    Systemic Calcitonin Therapy Based on the observations  that calcitonin receptors were found in the multi-nucleated  giant cells of central giant cell granuloma and the role of  calcitonin in inhibiting osteoclast function, systemic  administration of calcitonin has been practised to treat  central giant cell granuloma [31]. Calcitonin is adminis-  tered through a sub-cutaneous or intra-nasal route. Sub-  cutaneous administration involves 100 units per day for a  period of 18-21 months during which sequential radio-  graphs are obtained to monitor the remission of the lesion.    Unlike sub-cutaneous administration, the intra-nasal route  has better patient compliance but unpredictable absorption  rates [31].    Results with calcitonin therapy have been highly variable.  In some instances, they have been used to shrink the lesions  first, later to be followed by curettage.    Interferon Therapy Owing to the prominent vascular com-  ponent in central giant cell granuloma, the anti-angiogenic  properties of interferon alpha have been used as adjuvant  therapy following enucleation/curettage of the lesion.  Isolated interferon therapy without prior surgical procedure  led to partial resolution of lesions and is of limited value.  Kaban et al. had proposed a protocol that involved treatment  of aggressive central giant cell granulomas of the mandible  by a staged treatment of conservative surgical enucleation  (sparing the inferior alveolar nerve and teeth). This is fol-  lowed by administration of interferon Alpha 2 or beta  (3,000,000 units/m?) 48-72 h after surgery, given once daily  by a sub-cutaneous route for a period of 6 months or till a  period when CT scan showed complete regeneration of bony  defect [32]. Their study was based on the hypothesis that  these lesions are vascular proliferations, thus explaining the  high success rate in response to anti-angiogenic therapy in  their experience [32].    Bisphosphonates Bisphosphonates that have an antagonis-  ing effect on the osteoclastic activity. Owing to the virtue of  this property, bisphosphonates have been used in conjunc-  tion with intra-lesional steroids in central giant cell granu-  loma with promising results [33].    Denosumab Denosumab is a human monoclonal antibody  that binds to the RANK ligand located on the surface of  osteoclasts and deactivates them. The stromal cells of giant  cell tumour have been shown to secrete RANKL and  upregulate osteoclast activity and development. Recent  Phase-II clinical trials on the use of denosumab in giant  cell tumours of long bones showed that it reduces the need  for morbid surgeries [34, 35]. A single report on the use of  denosumab in central giant cell granulomas of jaws in two  patients was recently published and had claimed very  promising results involving complete remission of jaw  lesions. However, studies involving a larger sample with  longer follow-up periods are awaited to know the exact  risk-benefit status of this novel treatment option [36].    The aneurysmal bone cyst is a controversial lesion believed  to be a non-neoplastic and exaggerated reactive response of  vascular tissues of bone. It is a pseudocyst that presents as    expansile, osteolytic lesion often characterised by balloon-  ing distension of the cortex, that consists of blood-filled cav-  ernous spaces showing occasional osteoid material and  multi-nucleated giant cells [37].    The aneurysmal bone cyst generally occurs in patients  less than 30 years of age with a reported higher incidence  during the second decade of life with almost equal gender  predilection. Aneurysmal bone cysts of the jaws are rela-  tively rare comprising of only 1-3% of all aneurysmal  bone cysts occurring in the skeleton. The posterior region  of the mandible is the preferred site compared to maxilla  (6:1).   Most of these lesions present as expansile swellings  with or without perforation of the involved jaw bone,  causing facial asymmetry or displacement of adjacent  teeth and malocclusion. Pain, paresthesia and rapid pro-  gression of swelling can be seen occasionally. Dark  venous blood is generally obtained on aspiration  (Fig. 29.7a—c).   Pulsatile nature, thrill and bruit are generally not seen  in these lesions despite the prominent vascular component  associated with aneurysmal bone cysts. The presence of  these signs in an expansile, osteolytic jaw lesion would  rather indicate a high flow vascular malformation. The cli-  nician should recognise this and not mistake it for an  aneurysmal bone cyst, because doing an aspiration or  incisional biopsy of such high flow vascular malforma-  tions can lead to disastrous bleeding and potentially fatal  outcomes.    The exact mechanism regarding the origin of aneurysmal  bone cysts remains controversial. The reported hypotheses  include post-traumatic, reactive malformation, genetic pre-  disposition causing chromosomal translocation and minor  vascular injury in a pre-existing bone lesion leading to pool-  ing of blood in the stromal spaces creating bone destruction  [38].   This lesion can occur de novo as a primary aneurysmal  bone cyst or as a secondary phenomenon arising in pre-  existing lesions like central giant cell granuloma, ossifying  fibroma, fibrous dysplasia, osteosarcoma, fibrosarcoma and  other lesions [38]. It has been postulated that injury to the  capillary network in these lesions leads to extravasation of  blood. The associated capillary blood pressure readily  destroys unsupported stroma resulting in a blow out reaction  thereby producing the expansile and destructive aneurysmal  bone cyst.    Fig. 29.7 (a) Swelling left side body mandible. (b) Intra oral view of — scan showing the expansile lesion. (f) 3D CT showing the destruction of  swelling left lower posterior buccal cortex. (c) Aspirate showing blood _ bone  tinged fluid. (d) OPG showing lesion left body mandible. (e) Axial CT    Owing to its osteolytic nature, aneurysmal bone cyst pres-  ents as unilocular or multi-locular radiolucency often associ-  ated with cortical thinning and perforation with resorption of  roots seen occasionally. A classic sign commonly seen is the  ‘ballooning’ distension of the thinned out cortex occurring as  a result of a thin outline of reactive sub-periosteal bone for-  mation. CT and MRI scans of such lesions often demonstrate  blood and free fluid in these cavities (Fig. 29.74, e, f).   These typical features can sometimes be masked in those  aneurysmal bone cysts occurring as secondary phenomena in  pre-existing bone lesions. Such aneurysmal bone cysts pres-  ent as mixed radiolucent-radiopaque lesions.    Histopathologically, it consists of variable amounts of  fibrous connective tissue stroma with blood-filled sinusoi-  dal spaces, multi-nucleated giant cells and reactive woven  bone/osteoid. Correlating the histopathological and clinical  features, three variants of aneurysmal bone cysts were pro-  posed namely, the solid type, vascular type and mixed type  [39]. The solid type is associated with a dense stroma, few  sinusoidal spaces and blood vessels that correlates with the  absence of cortical perforation clinically and minimal  bleeding observed intra-operatively. The vascular variant  falls into the other end of the spectrum that shows loose  fibrous tissue stroma with large blood-filled cavernous  spaces causing extensive osteolysis and cortical perforation  that is frequently associated with brisk intra-operative  bleed. The mixed variant shows characteristics of both  these sub-types.    Complete Surgical curettage of the lesion is the most com-  monly followed treatment modality. Adjuvant therapies like  cryosurgery and electrocauterisation have been used to  reduce the chances of recurrence. Due to its vascular nature,  brisk bleeding is often encountered during surgery that gen-  erally ceases after complete removal of the lesion. Pre-  operative embolisation had been advocated in extensive,  vascular variants of aneurysmal bone cysts to reduce intra-  operative blood loss.   Resection is generally reserved for aggressive aneurysmal  bone cysts that have extensively resorbed the lower border of  the mandible or have caused a pathological fracture and  lesions that have recurred following conservative therapy.  The decision to perform segmental resection is also influ-  enced by the nature and extent of primary jaw pathology in  which the aneurysmal bone cyst has arisen. Segmental resec-  tion has been recommended as the treatment option for sec-    ondary aneurysmal bone cysts occurring in ossifying  fibromas, giant cell granulomas and osteoblastomas [40].    Aneurysmal bone cysts have relatively higher recurrence  rates compared to central giant cell granuloma [38]. This has  been attributed to incomplete removal of the lesion during  curettage/marginal mandibulectomy. The multi-locular  nature of the lesion can sometimes limit the access leading to  residual pathological tissue that causes increased intra-  operative bleeding and also gives rise to recurrences usually  in the first year following surgery.    Brown tumour is a misnomer as it is not a true neoplasm, but  a localised area of osteolytic defect caused by increased  osteoclastic activity and demineralisation of bone that is  induced by excessive secretion of parathyroid hormone. It is  considered to be an intra-osseous reactive lesion [4].    Hypersecretion of parathyroid hormone can occur due to  Primary (benign/malignant adenoma of parathyroid gland),  secondary (pre-existing kidney disease leads to compensa-  tory overactivity of parathyroid) or tertiary causes (parathy-  roid tumours arising due to prolonged hyperactivity induced  by secondary causes). Irrespective of the origin, the resultant  effect is hypercalcaemia (caused by mobilisation of calcium  from bone to bloodstream) and altered phosphate levels that  give rise to the entire spectrum of signs and symptoms of this  disease. These include disturbances in ion metabolism,  demineralisation of bone, kidney stones, gastrointestinal dis-  orders and muscle weakness. Hence, hyperparathyroidism is  also referred to as the ‘disease of bones, stones, abdominal  groans and psychic moans’ [41].    Brown tumour is a localised, lytic bone defect character-  ised by a mass of reactive fibrous tissue that presents as  swelling with cortical expansion, perforation occasionally  associated with pain and pathological fracture. The lesion  occurs in adults above 50 years of age and has a female to  the male pre-dilection of 5:2 and can occur in any bone but  more common sites are long bones, pelvis, ribs, maxilla  and mandible [42]. Co-existing multiple synchronous  lesions in the jaws and at other skeletal sites can also occur    Fig. 29.8 (a) Lesion right  posterior maxilla. (b) Lesion  anterior mandible. (c) OPG  showing the changes (red  circles)    [43] (Fig. 29.8a—c). Bone manifestations usually occur in  the late stages of hyperparathyroidism, and brown tumours  are picked up during the diagnostic work-up for the same.  Rarely, brown tumour of the jaw may be the first manifesta-  tion of primary hyper parathyroidism [44, 45]. They can  cause significant bone destruction leading to facial asym-  metry, displacement of teeth, malocclusion pathological  fracture etc.    Since it is not possible to histopathologically distinguish  brown tumour from central giant cell granuloma, biochemi-  cal tests are mandatory to confirm its diagnosis. Elevated  serum calcium (>10.4 mg/dl), decreased serum phosphate  level, elevated parathormone levels, ultrasonography to iden-  tify parathyroid adenomas (primary hyperparathyroidism),  and renal function tests to rule out renal disease (secondary  hyperparathyroidism) constitute the sequence of diagnostic  work up to diagnose hyperparathyroidism [45].    It shows a well-defined mono-locular or multi-locular well-  demarcated lesion that is purely lytic. There are significant  root resorption and loss of lamina dura.    Brown tumour very closely resembles central giant cell gran-  uloma, and these two lesions are indistinguishable on histo-  pathology. Features such as_ the proliferation of  multi-nucleated giant cells, osteoclasts present in a rich  fibro-cellular and vascular connective tissue stroma with    scattered areas of haemorrhagic foci and haemosiderin pig-  mentation are seen. The presence of haemosiderin renders  this lesion its characteristic brown/brownish yellow colour  and hence the name brown tumour.    Spontaneous resolution/remission of brown tumour gener-  ally occurs after treatment of the underlying cause of  hyperparathyroidism. Primary hyperparathyroidism is  treated by excision of parathyroid adenoma/gland.  Treatment of renal disease, vitamin D deficiency is done in  the cases of secondary hyperparathyroidism. Refractory  lesions that fail to resolve or incomplete remissions after  treatment of underlying cause would require surgical curet-  tage [44, 45].    Brown tumours are generally slow-growing lesions that can  be locally destructive. Invasion into surrounding structures  may cause a variety of symptoms. Small lesions usually  resolve spontaneously once the underlying condition (hyper-  parathyroidism) is treated whereas large lesions take about  6-12 months to subside.    1. Central Giant cell granuloma (CGCG) and brown  tumour are indistinguishable histologically. An  incisional biopsy report of CGCG should prompt  the clinician to ask for biochemical investigations  to rule out the brown tumour, that is characterised  by increased serum levels of calcium, phosphate,  alkaline phosphatase and parathyroid hormone.   2. It is crucial to diagnose brown tumours that are  invariably reported as CGCG on incisional biopsy  because treatment of hyperparathyroidism will  generally lead to spontaneous resolution of brown  jaw tumours, thereby avoiding unnecessary surgi-  cal procedures of jaw lesions.   3. Aneurysmal bone cysts have varied clinical, radio-  logical and histological presentations.   4. Secondary aneurysmal bone cysts that arise in pre-  existing pathologies have a higher tendency to recur  if treated by conservative surgical methods like  curettage.    Chronic sclerosing type of osteomyelitis occurs as a result of  low-grade and long-standing infection of the marrow spaces  that is characterised by areas of reactive bone sclerosis  extending over a larger area (diffuse sclerosing) or localised  to one or two teeth (focal sclerosing) [4].   Garre’s osteomyelitis also known as proliferative perios-  titis is a sub-type of osteomyelitis that occurs in children. It  is characterised by reactive sub-periosteal bone formation  in response to chronic low-grade infection. Predominantly  occurring in the posterior region of the mandible, it is best  seen on an occlusal radiograph or an axial section CT scan  as onion skin-layered appearance of the expanded bony  cortex.   Rarely, malignancies like osteosarcoma (juxtacortical and  parosteal), chondrosarcoma, fibrosarcoma and others can  closely mimic Garre’s osteomyelitis leading to a diagnostic  dilemma and sub-optimal treatment.   These lesions are discussed in detail in other chapters of  the book.    A variety of reactive soft tissue and bony pathologies occur  in the oro-facial region that arises in response to chronic low-  grade inflammation, trauma, metabolic and hormonal influ-  ences. These lesions very closely mimic benign and  malignant neoplasms in their clinical, radiological and histo-  logical presentations. Knowledge about their etiopathogene-  sis, Clinical behaviour patterns is of paramount importance  for providing appropriate treatment.    A 53-year-old male patient reported with a chief complaint  of bony hard swelling over the left side lower jaw of 8 month  duration.   Bony hard swelling over the left body of the mandible was  noted with the expansion of buccal and lingual cortical plates  (Fig. 29.5a, b).   Imaging: Orthopantomogram revealed unilocular radiolu-  cency with a sclerotic border and x-ray occlusal view showed  a bicortical expansile, osteolytic lesion at the left body of  mandible, with areas of osteosclerosis (Fig. 29.5c, d).    Incisional Biopsy: Incisional biopsy done under local  anaesthesia proved it to be central giant cell granuloma.  Biochemical tests for assessment of serum parathormone,  calcium, phosphate levels were performed, and the possibil-  ity of brown tumour of hyperparathyroidism was ruled out.   Surgical Plan: Considering bi cortical perforation and  thinning of lower border caused by the lesion, segmental  mandibulectomy through submandibular approach + man-  dibular reconstruction plate fixation was performed.   Postoperative Period: Post-operative period was unevent-  ful. The patient was last seen three years after surgery and  was found to be recurrence-free.    A 60-Year-old male with a complaint of an asymptomatic  slow-growing swelling in the upper jaw of 10 months  duration.   A single firm to hard swelling measuring approximately  4 x 3 cm located over the right maxillary posterior alveolus  causing buccolingual expansion, vestibular obliteration was  found. It was extending from the mesial aspect of right max-  illary 1st molar to the maxillary tuberosity area. The swelling  was non-tender, firm to hard in consistency, with normal  overlying mucosa. There was associated odontogenic focus  of sepsis, but there was grade-II mobility of right maxillary  Ist molar.    Pre-operative Diagnostic Work-up  Imaging: A pre-operative CT scan revealed a unilocular  radiolucency with scattered areas of radio-opacity located at  right maxillary posterior alveolus that was causing buccal  cortical expansion, thinning and even perforation with  denuding of the roots of the Ist molar. Superiorly the lesion  was found to be extending till the body of the zygoma and  just abutting the floor of the maxillary sinus.   Histopathological and Biochemical Evaluation: An inci-  sional biopsy of the lesion was performed under local anaes-  thesia, that was reported as a central giant cell granuloma of  the maxilla. A thorough biochemical evaluation was done to  rule out brown tumour of hyperparathyroidism as both the  lesions are indistinguishable histopathologically. Serum cal-  cium, parathormone, and phosphate were within the normal  limits.   Surgical Plan: Extended alveolectomy of the right poste-  rior maxillary alveolus + nasal antrostomy + two-layered    closure of the resultant defect with oroantral communication  by mobilisation of the buccal fat pad and adjacent Bucco-  palatal mucoperiosteum. Following excision of the lesion,  since maxillary sinus was breached, the resultant defect was  packed with ribbon gauzed soaked in whitehead’s varnish,  and a trans nasal inferior meatal antrostomy was done,  through which the tip of the pack was brought outside and  knotted for removal on the 12th day. A two-layered water-  tight closure of the wound was achieved.   Post-operative Period: The wound healed uneventfully.  The patient was last seen 4 years post-operatively and was  free of disease.    A 38-year-old female with a complaint of swelling at the left  side lower jaw of 1-year duration.   Figure 29.7a A single firm to hard swelling was located over  the left body of mandible, non-tender with normal overlying  skin & mucosa. On palpation, buccal and lingual cortical  plate expansion (Fig. 29.7b) with eggshell crackling sign-  positive suggestive of expanded and thinned out cortical  plates causing microfractures on digital pressure.   Imaging: Orthopantomogram revealed a radiolucent lesion  in the left body of the mandible with focal radio-opacities  located in the anterior aspect of the lesion. The lesion was  causing root resorption, thinning of mandibular lower border  and was extending from lower left 2nd molar to lower left  lateral incisor (Fig. 29.7d).   CT scan confirmed the presence of an expansile, lytic  lesion with a characteristic ‘ballooning distension of the buc-  cal and lingual cortical plates’. It also showed scattered areas  of radio-opacities & multilocularity in the anterior region of  the lesion and bi-cortical perforation along its posterior  aspect.   ‘Ballooning distension’ of the cortex with scattered areas  of radio-opacities within a radiolucency was suggestive of  secondary aneurysmal bone cyst arising in a pre-existing  lesion (Fig. 29.7e).   Reconstructed CT scan showing bi-cortical perforation  and lower border thinning at the mandibular body (Fig. 29.7f).   Aspiration: Figure 29.7c Dark venous blood of about  8-10 ml could readily be aspirated from the lesion.   Incisional Biopsy: Correlating the bloody venous aspi-  rate, clinical & radiological findings, a clinical diagnosis of  the aneurysmal bone cyst was made. However, owing to the  change in radiodensity in the anterior aspect of the lesion (as    evident on CT scan), an incisional biopsy was performed to  rule out the presence of a hybrid lesion or co-existing  pathology.   Diagnosis: A histopathological diagnosis of secondary  aneurysmal bone cyst arising in ossifying fibroma of the  mandible has been made.   Surgical Plan: Considering the hybrid nature of the  lesion, bi-cortical perforation, thinning of lower border, the  proposed surgical plan was segmental mandibulectomy and  reconstruction.    A 40-year-old female patient reported with a complaint of  swelling over the lower jaw of 18 months duration and swell-  ing over the right side of the upper jaw of 6 months  duration.   A firm to hard swelling was noted in the mandibular anterior  dentoalveolar region extending from right lower 2nd premo-  lar to lower left lateral incisor (Fig. 29.8a). There was a dis-  placement of lower anterior teeth. Another similar firm  swelling was noted in the right maxillary posterior dentoal-  veolar region in the region of missing right Ist maxillary  molar (Fig. 29.8b). Overlying mucosa appeared normal in  both the swellings.   Imaging: Figure 29.8c Orthopantomogram revealed a uni-  locular radiolucency with a sclerotic border located in rela-  tion to the periapical region of right lower premolars. A  poorly defined mixed lesion (radiolucent lesion with foci of  radio opacities) was noted in the right maxillary posterior  region.   Incisional Biopsy: An incisional biopsy of both the lesions  was performed under local anaesthesia. Both the lesions  were reported as central giant cell granulomas.   Biochemical Evaluation: Since synchronous giant cell  granulomas are generally rare and as these lesions are histo-  pathologically similar to browns tumour, biochemical evalu-  ation was performed. Serum parathormone was remarkably  elevated along with raised serum calcium levels, while renal  function parameters were well within normal limits.   Ultrasound Evaluation of Neck: An ultrasound evaluation  of neck revealed parathyroid adenoma on the left side.   Diagnosis: After correlating the biochemical and sono-  graphic examination, a diagnosis of primary hyperparathy-  roidism is made. The osteolytic lesions of mandible and    maxilla were diagnosed as Synchronous brown tumours of  maxilla and mandible.   Surgical Plan: The patient was advised parathyroidec-  tomy for primary hyperparathyroidism followed by the wait  and watch policy for synchronous brown jaw tumours to  undergo self-resolution. But spontaneous resolution the jaw  lesions was very slow following eight months after parathy-  roidectomy and the patient wanted surgical removal of the  brown jaw tumours. They were treated by marginal mandib-  ulectomy and alveolectomy of posterior maxilla.    1. Marx RE, Stern D. Oral and maxillofacial pathology: a rationale  for diagnosis and treatment. Hanover Park, IL: Quintessence  Publishing; 2012.   2. Eversole LR, Rovin S. Reactive lesions of the gingiva. J Oral Pathol  Med. 1972;1(1):30-8.   3. Neville BW. Soft tissue tumours. In: Oral and maxillofacial pathol-  ogy. London: Elsevier; 2009. p. 507-70.   4. Wick MR, McDermott MB, Swanson PE. Proliferative, repara-  tive, and reactive benign bone lesions that may be confused diag-  nostically with true osseous neoplasms. 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Rosenberg AE, Nielson GP, Fletcher JA. Aneurysmal bone cyst. In:  CDM F, Unni KK, Mertens F, et al., editors. WHO classification of  tumours: pathology and genetics of head and neck tumours, vol. 9.  3rd ed. Lyon: IARC; 2005.   Struthers PJ, Shear M. Aneurysmal bone cyst of the jaws:(ID.  Pathogenesis. Int J Oral Maxillofac Surg. 1984; 13(2):92-100.  Motamedi MH, Navi F, Eshkevari PS, Jafari SM, Shams MG,  Taheri M, Abbas FM, Motahhari P. Variable presentations of aneu-  rysmal bone cysts of the jaws: 51 cases treated during a 30-year  period. J Oral Maxillofac Surg. 2008;66(10):2098-103.   Sun ZJ, Zhao YF, Yang RL, Zwahlen RA. Aneurysmal bone  cysts of the jaws: analysis of 17 cases. J Oral Maxillofac Surg.  2010;68(9):2122-8.    Abdelrahman TE. Brown jaw tumors: challenges and outcomes. Int  Surg J. 2017;4(11):3586-9.   Ullah E, Ahmad M, Ali SA, Redhu N. Primary hyperparathyroid-  ism having multiple Brown tumors mimicking malignancy. Indian  J Endocrinol Metab. 2012;16(6):1040.   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The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in  a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.    Fibro-ossoeus lesions have posed a diagnostic dilemma since  the beginning, when first case was reported in late 19th cen-  tury. Since then various lesions are included in this group,  yet the understanding of the lesions remains obscure for the  clinican/surgeon. The main reason for this, is their histologi-  cal resemblance with one another, where they all show vary-  ing degrees of healthy bone replaced by fibrous tissue and  some amount of bone/cementum like tissue intermingled in  between. This chapter is written with the aim of simplifying  these group of bony lesions for its readers and highlighting  the key idea of interdisciplinary approach in the management  of these lesions where the oral pathologist along with radi-  ologist and clinician play a pivotal role in differentially diag-  nosing these lesions, for the maxillofacial surgeon to chose  and perform her/his duty of managing them, rightfully, for  their patients. The spectrum of these lesions have seen sev-  eral changes during the course of history yet there is still  ample scope for ambiguity in identification and classification  of the lesions, hence the authors have chosen few most com-  monly encountered lesions in Indian subcontinent, for the  description and discussion.   Fibro-osseous lesions (FOLs) are miscellaneous and chal-  lenging group of intra-osseous lesions posing a diagnostic  dilemma for the clinician as well as the pathologist and this  makes them interesting to treat and manage for the surgeon  [1]. It was Boyko who first reported a case of craniofacial  fibrous dysplasia, diagnosed at that time as osteofibroma, in    Electronic Supplementary Material The online version of this chap-  ter (https://doi.org/10.1007/978-98 1-15-1346-6_30) contains supple-  mentary material, which is available to authorized users.    T. Kaur (4)  Department of Oral and Maxillofacial Surgery, Government Dental  College and Hospital, Jamnagar, Gujarat, India    © The Association of Oral and Maxillofacial Surgeons of India 2021    1936, which was called leontiasis ossea, the term first  described by Virchow in 1862, for bony lesions involving  upper facial bones resulting in lion-like faces. Clinicians and  pathologists have gone through a drastic change in their  understanding of these lesions since then yet pathogenesis  and progression still needs further investigation [2].   One thing that is common in all these lesions is that nor-  mal bone is replaced by connective tissue and fibroblasts;  occasional foci of mineralisation is seen, with varying  degrees of bone- or cementum-like tissue. The biological  behaviour of these lesions ranges from benign and indolent  to aggressive, inflammatory and neoplastic [1].   The diagnosis is difficult to obtain on the basis of histopa-  thology alone, clinical history and radiographic details have an  important role to play in the decision-making of the manage-  ment. Most often than not, pathologists may not be able to  comment more than just benign fibro-osseous lesion in the  absence of additional clinical and radiographic information [1].   Though considered as one of the most confusing and  challenging pathological processes, it was the meticulous  hard work of Charles A Waldron, an American Oral  Pathologist, who was first to describe these lesions in a sys-  tematic way and propose the classification, in the year 1985,  which was later revised by himself in the year 1993 [3, 4].   With the evolution of technology and a better clinical  understanding of the lesions as well as the availability of  ample literature, various other classifications have emerged  from time to time [5, 6].    Fibro-osseous lesions have undergone a turbulent phase with  regard to its classification and categorisation and in this chap-  ter, it may not be possible to include all the available classifi-  cations, but the major ones have been referred to. The major  changes in classifications are seen in the publications by  Waldron [5], Waldron [6], Slootweg [7], WHO [8], Speight    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1-15-1346-6_30    and Carlos [9] and Eversole et al. [1]. As all the changes in  classifications have not been included in the chapter, readers  are encouraged to refer the concerned publications. Some of  the commonly used classifications are as follows.    1. Fibrous dysplasia (FD)  (a) Monostotic  (b) Polyostotic  2. Fibro-osseous (cemental) lesions’ plausible origin in the  periodontal ligament  (a) Periapical cemental dysplasia  (b) Localised fibro-osseous-cemental lesions (presum-  ably reactive in nature)  (c) Florid cemento-osseous  cementoma)  (d) Ossifying and cementifying fibroma  3. Fibro-osseous neoplasms of uncertain or detectable rela-  tionship to those arising in the periodontal ligament  (a) Cementoblastoma, osteoblastoma and _ osteoid  osteoma.  (b) Juvenile active-ossifying fibroma and other so called  aggressive-ossifying/cementifying fibromas.    At the core of these classifications is the spectrum of clinico-  pathological entities in which the diagnosis can only be made  by the correlation of clinical, radiological and histological  features.    1. Ossifying fibroma (OF)  2. Fibrous dysplasia  3. Osseous dysplasia  (a) Periapical osseous dysplasia  (b) Focal osseous dysplasia  (c) Florid osseous dysplasia  (d) Familial gigantiform cementoma  . Central giant cell granuloma  . Cherubism  . Aneurysmal bone cyst  . Solitary bone cyst    1. Fibrous Dysplasia  (a) Monostotic FD  (b) Polyostotic FD  (c) Craniofacial FD    2. Osseous Dysplasia  (a) Periapical Osseous Dysplasia  (b) Focal Osseous Dysplasia  (c) Florid Osseous Dysplasia  (d) Familial Gigantiform Cementoma  3. Ossifying Fibroma  (a) Conventional Ossifying Fibroma  (b) Juvenile Trabecular-Ossifying Fibroma  (c) Juvenile Psammomatoid-Ossifying Fibroma    In 2008, Eversole et al. gave a comprehensive classifica-  tion by including developmental lesions, neoplastic lesions  and inflammatory/reactive processes. This classification  emphasised that final diagnosis can be attained by the cor-  relation of microscopy, imaging and clinical features  together and not on the basis of histopathological features  alone.    1. Bone dysplasias  (a) Fibrous dysplasia  (i) Monostotic  (11) Polyostotic  (iii) Polyostotic with endocrinopathy (McCune-Albright)  (iv) Osteofibrous dysplasia  (b) Osteitis deformans or Pagets disease  (c) Pagetoid heritable bone dysplasias of childhood  (d) Segmental odontomaxillary dysplasia  2. Cemento-osseous dysplasias  (a) Focal cemento-osseous dysplasia  (b) Florid cemento-osseous dysplasia  3. Inflammatory/reactive processes  (a) Focal sclerosing osteomyelitis  (b) Diffuse sclerosing osteomyelitis  (c) Proliferative periostitis  4. Metabolic disease  (a) Hyperparathyroidism  5. Neoplastic lesions (ossifying fibromas)  (a) Ossifying fibroma  (b) Hyperparathyroidism jaw lesion syndrome  (c) Juvenile-ossifying fibroma  (i) Trabecular type  (ii) Psammomatoid type  (d) Gigantiform cementomas    Based on the above-mentioned classification systems,  author have selected few most commonly occurring BFOLs  (Benign fibro-osseous lesions), which will allow a better  understanding of these lesions, from a maxillofacial sur-  geon’s point of view.   It is apparent from this wide spectrum of FOL that a diag-  nosis cannot be made from pathology reports alone and it has    to be correlated with the clinical and radiological findings  [11]. BFOL form a wide spectrum of diseases, which occur  intra-osseously and is characterised by similar microscopic  pictures with hypercellular fibroblastic stroma and varying  amounts of bone, cementum and other calcified structures. El  Mofty stated that reactive, dysplastic, developmental and  neoplastic processes are included under the broad umbrella of  BFOLs and the treatment given varies from case to case [12].    Fibrous Dysplasia is a benign dysplastic disease with a well-  approved genetic cause in GNAS | (Guanine nucleotide-  binding protein alpha-stimulating activity polypeptide 1)  gene. The clinical severity of the disease depends on the  stage of foetal life (prenatal/postnatal) at which gene muta-  tion occurs. So far, the identification of GNAS/ mutations are  the most useful molecular tool to differentiate fibrous dys-  plasia from other fibro-osseous lesions [13].    There are four main clinical subtypes of FD depending on  the time of mutation in GNAS 1   (b) Polyostotic FD affecting multiple bones at the same  time: Mutation in the late embryonic stages of life.   (c) McCune—Albright syndrome in which multiple bony  lesions are seen along with skin pigmentations and endo-  crinopathies presenting itself as precocious puberty and  hyperthyroidism: Due to mutation in early embryonic  stages of life.    Craniofacial variant will be discussed in detail, as it is the  most common FD encountered in the maxillofacial region.   FD is the disease of growing bones and the majority of  lesions are diagnosed in first two decades of life, without any  predilection for gender or race. Though mandibular lesions  are purely monostotic, but the lesions involving maxilla,  which invariably involve zygoma, sphenoid and other adjoin-  ing bones of the craniofacial skeleton, are not truly mono-  stotic and hence may be suitably referred to as Craniofacial  FD. Since multiple adjoining bones are involved of the same  anatomic region, term polyostotic is avoided. Craniofacial  FD appears in few commonly seen patterns,    Clinically, painless expansion of the affected area with  facial asymmetry is the common presentation of FD. Rarely  does a lesion expand the bone to cause structural weakening.  Thickening of the skull bones and obliteration of the foram-  ina of the base of the skull occasionally can present variously  as headache, proptosis, visual loss, anosmia and hearing  loss.    Radiographic features vary depending on the stage at which  the lesion is diagnosed. Early onset lesions appear radiolu-  cent and later as they age, the classical ‘ground glass appear-  ance’ (Fig. 30.1) is the identifying feature.   The lesion is ill defined and is radiologically impercep-  tible from the adjoining normal bone. Ground glass  appearance is due to radiodensity caused by abundance of  woven bone, which also leads to fuzziness of the boundar-  ies, and strict delineation of lesion from the normal bone  is difficult on the radiograph. Poorly defined borders are  the diagnostic clue for FD and also differentiate it from  Ossifying fibroma, which has well-defined appearance on  the radiograph. Publications have stressed on the impor-  tance of CT and CBCT as investigative modalities of  FOLs [14].   The clinical case scenarios | and 2 are provided for the  readers to appreciate the difference in the CT images between  early and long-standing lesions   A 17-year-old male with noted swelling in the upper right  maxilla posterior vestibule region and he was aware of the  swelling for about | month.    Fig. 30.1 Occlusal image showing ground glass appearance in a  36-year-old female, who had aymptomatic bilateral body region man-  dible swelling    Fig. 30.2 (a) Clinical picture of FD right upper posterior buccal sul- _ lost in IOPA. (ec) Axial view CT. (d) Coronal view CT. (e) Sagittal view  cus. (b) Occlusal view showing ground glass appearance, no root reso- CT  prtion, no root displacement, hazy margins, lamina dura appeared to be    Fig. 30.3 (a) Clinical image. (b) Coronal CT showing more dense/opaque appearance of the lesion. (c) Axial image    Clinically, the lesion was Ovoid, well defined, non-tender  and firm with no palatal expansion, involving the buccal suc-  lus of tooth 13-16 (Fig. 30.2a).   Occlusal X-ray showed ground glass appearance  (Fig. 30.2b), There was no root resorption, no root tilting,  margins were hazy and lamina dura lost.   CT scan shows well-defined lesion (Fig. 30.3c-e—axial,  coronal and sagittal views, respectively).   A bone incision biopsy was done and the final diagnosis  was that FD. It was decided to observe the lesion till growth  is completed; however, the patient was lost for follow up   This patient in his late thirties was aware of the swelling  on the right posterior upper jaw for past 5-6 years. After an  initial biopsy proved it to be FD, the lesion was excised com-  pletely under GA.    Histologically, FD shows irregularly shaped trabeculae of  immature woven bone dispersed in cellular fibroblastic  stroma. The bone trabeculae evolve directly from stroma and  assume delicate curvilinear patterns, which appear like  ‘Chinese letters’ [15]. The osteoid is generally not rimmed  with osteoblasts and develops into lamellar bone as the lesion  matures. Such may not be the case with extra gnathic lesions.    In a large majority of cases, lesions show the tendency of  slow growth and eventually stabilise with the cessation of the  growth phase. Indications for surgical treatment include  functional deficits or significant cosmetic deformity. The aim  of treatment is to restore function and cosmetic symmetry.    The involvement of the bone may range from minimal to  functional and/or esthetic deformity being present. Based on  patient’s age, the presence/absence of cosmetic and func-  tional deficits and the growth rate, the treatment is currently  designed in the following way [16] (Video 30.1).   2. Conservative approach in the form of surgical  recontouring and reshaping.    In the case of minimal involvement, no surgical interven-  tion may be needed but when involvement is more signifi-  cant, surface shaving of excess bone, for cosmetic reasons  may be done. Radical surgical approach is preferred in the  case of significant functional and aesthetic deficit.   A treatment scheme offered by Chen in 1990 [17] is  helpful in determining the approach depending on the  extent of conditions. The lesions are defined as per the  regions, in Zone 1, i.e. frontomaxillofacial are, it is advised  that they are completely excised and reconstructed hence-  forth. In Zone 2, i.e. hair-bearing cranium, observation and  conservative or radical approach as and when needed.  Whereas in Zone 3, which is central cranial base, more  conservative or observational approach is required due to  the difficult location of neurovascular bundle, lastly Zone  4 lesions involving dentate maxilla and mandible are  advised conservative treatment in the form of surgical  recontouring and shaping. Optic canal decompression was  advised on patients with orbital dysplasia and decreasing  visual acuity.   Riclade in 2001 in his review article stated that in cranio-  facial dysplasia, early treatment is advised in progressive  sensory disturbances, in order to reduce the problems caused  by decompression at a later stage [18].   Non-surgical treatment has a limited role, radiotherapy is  contraindicated. Steroids show some effectiveness in reduc-  ing bone pain and temporary relief from symptoms due to  nerve compression. Calcitonin and pamidronate have shown  some promise in recent studies but the results of long term  trials are awaited [16].   Monostotic lesions of the craniofacial complex need to be  differentiated from other FOLs like cemento-ossifying  fibroma (COF) and diffuse-sclerosing osteomyelitis of the  mandible [15] while COF most commonly appears in young  adults in tooth bearing areas of mandible and maxilla, it is  well defined and can be separated or scooped out from the  adjoining healthy bone easily.    Clinical case scenario 3 is a 14-year-old boy who reported  with a recurrent lesion on upper left buccal posterior alveo-    lus. The clinical, radiological and surgical findings were sug-  gestive of a COF; however, the pathology report was that of  FD. This case is shown to highlight the varied pathology  reports, which can be expected in dealing with lesions under  the BFOL spectrum (Fig. 30.4a—d).    Clinical case scenario 4 (Fig. 30.5a—c) is given to show  lesion, which had initial differential diagnosis of FD, but  pathology report showed it to be sclerosing osteomyelitis   In 2008, eversole classification inflammatory reactive  process containing focal sclerosing osteomyeliotis/diffuse  sclerosing osteomyelitis (DSOM) and proliferative periosti-  tis were categorised under BFOL.   Figure 30.6 is an OPG of a 11-year-old child who pre-  sented with recurrent pain and swelling left side body man-  dible. OPG shows a diffuse ground glass appearance, with  changes in the trabecular pattern on the whole of the left  ramus and body mandible. A provisional diagnosis of DSOM  can be made. Unfortunately, the patient didn’t report for fur-  ther investigations. OPG is included to demonstrate the alter-  ation of the trabecular pattern.    30.4 Ossifying Fibroma/Cementifying  Fibroma/Cemento-Ossifying Fibroma  (COF) and Juvenile (Aggressive)-  Ossifying Fibroma    These were traditionally a group of Fibro-osseous lesions  with neoplastic tendencies. COF has had its own share of  controversies, being included previously under BFOLs. The  recent update in 2018; however, accepts COF as odontogenic  in origin and had been placed under mesenchymal odonto-  genic tumours [19]. Another entity with a similar clinical  picture is central odontogenic fibroma, which is also under  benign mesenchymal tumours. Lesion that produces cemen-  tum including COF and cementoblastoma, thus, currently  has found a new place.   In 2017, the consensus group felt that the term cemento-  ossifying fibroma is suitably descriptive and indicates that  these lesions are specific to the tooth-bearing areas of the  jaws and can be distinguished from the two juvenile variants  of ossifying fibroma. This clearly distinguishes it from ossi-  fying fibromas that are non-odontogenic and are classified  under benign fibro- and chondro-osseous lesions. The three  variants are, therefore, defined as cemento-ossifying fibroma,  juvenile trabecular-ossifying fibroma and _ juvenile  psammomatoid-ossifying fibroma [20-22].    Fig. 30.4 (a) Clinical image of swelling left upper buccal alveolus in a  14-year-old boy. (b) Axial CT image showing flecks of radiopacities.  (c) Shows the lesion exposed, note the gritty nature, which could be    They are slow growing in nature in adults, but show aggres-  siveness in the younger age group. The teeth are generally  displaced. Ossifying Fibromas demonstrate a well delineated  or encapsulated cellular fibrous connective tissue with vary-  ing amounts of osseous products like bone and cementum  (spherical calcification).   Lesions are more commonly seen in mandible (77%)  especially the molar region and are found exclusively in  jaws. The peak age is 3rd and 4th decades of life and very  strong female pre-dilection (almost 5:1). The juvenile variant  (Juvenile-Ossifying Fibroma), which is also more aggres-  sive, is seen in the younger age group [23].    easily shelled out with relative ease, in this case. (d) Intra-operative  image where the lesion was shaved out from the alveolar bone via a  mucoperiosteal flap approach    It is a well-demarcated radiolucent lesion, in the initial  stages, separated from the surrounding healthy bone. Usually,  a solitary lesion and is unilocular. The well-demarcated  radiolucent/radiopaque appearance is the main differentiat-  ing consideration with Fibrous Dysplasia. Appearance is  dependent on the maturity of the lesion, i.e. purely radiolu-  cent (initial stages); mixed with radiopaque foci or radi-  opaque. The radiographic presentation of bowing of mandible  with thinning and weakening of the lower border, particu-  larly in large expansive lesions, is seen. Resorption or diver-  gence of roots may result due to continued growth.    Fig. 30.5 (a,b) OPG ant coronal CT cuts show evident changes in the  right ramus of a 10-year-old girl, who presented with progressing facial  asymmetry on the right side ramus region. The provisional diagnosis    Ossifying fibromas of craniofacial skeleton are divided into  two categories depending on the cell of origin.   (B) Juvenile (aggressive)-Ossifying Fibroma [9, 24—26]:  subcategorised as (Table 30.1) (Fig 30.7)  1. Juvenile trabecular-Ossifying Fibroma (JTOF)  2. Juvenile Psammomatoid-ossifying fibroma (JPOF)    was of FD, but the bone biopsy (c) report was suggestive of sclerosing  osteomyelitis    COF is a slowly growing benign neoplasm commonly seen  in the 3rd to 4th decades of life, if left untreated can enlarge  to a significant size. Since it is radiographically as well as  microscopically well circumscribed and shells out from the  surrounding bone with little effort, it is curettage or enucle-  ation a preferred initial treatment option. An important fea-  ture is, it is well defined and can be easily shelled out from  the adjoining normal bone, grossly the lesion can be sepa-  rated out in one piece or a few large chunks. The recurrence  rate is variable and unpredictable. Surgical curettage is an    Fig.30.6 OPGina  11-year-old child showing the  diffuse change in the  trabecular pattern at the left  body/ramus region of    Densely cellular,  immature bone and  osteoid in a trabecular  pattern, osteoblast  rimming seen  Progressive and rapid  expansion of lesion,  pain may not be  present, in maxilla can  produce nasal  obstruction and  epistaxis   Orbital extension of  sino-nasal tumors may  present as proptosis,  visual complaints nasal  stuffiness etc    acceptable trteatment [27]. Lesions exhibiting more aggres-  sive behaviour and recurrence may need to undergo resec-  tion. The anatomical location and age of the patient and  aggressiveness of the lesion have a role in deciding the treat-  ment modality of the lesion.    Clinical case scenario 5 (a case of COF affecting the right  side body of the mandible) (Fig. 30.8a—e).    Fig. 30.7 (a, b) Coronal and panoramic CT views in a 26-year-old  man with long-standing swelling of the left side maxilla and cheek  bone—the case of JOF—lesion fills the left hand side of the nose and  paranasal sinuses    Fig. 30.8 (a) Swelling rt body mandible in 29-year-old female, clinical picture. (b) Panoramic image of the CT scan. (ce) Axial CT image showing  the bone destruction. (d) Surgical bed after excision of the lesion. (e) Cut section of the fibrous lesion    Osseous dysplasia is a non-neoplastic, commonest, least  understood fibro-osseous lesion occurring in tooth-bearing  areas of the jaws. The cause of misunderstanding lies at the  similarities shared at the clinical and histological levels with  other fibro-osseous lesions like fibrous dysplasia and ossify-  ing fibroma and even few neoplasias [28].   Since these lesions lie in close association with the peri-  odontal ligaments of the tooth-bearing segment of the jaws,  and histopathologically as well, they bear close similarity  with PDL, the strong suspicion of the origin in PDL cannot  be ruled out.    Two main types are recognised, based on the clinical  and radiological features.    Localised variety includes  (a) Periapical cemento osseous dysplasia (PCOD)  (b) Focal cemento osseous dysplasia (FCOD)    Ideally, these lesions can be identified clinically and radio-  graphically without the need for the biopsy, as the presen-  tation is pathognomonic    Su et al. in 1997 have published a series of 316 cases to  distinguish the clinical, radiological and pathological fea-  tures of the cement osseous dyplasias [29, 30].    The clinical and radiographic presentation of PCOD is  well established. There is a marked predilection for  females (14:1) and Afro-Caribbean women [2], and com-  monly seen in and around the third decade of life, rarely  before the age of 20.   Predominantly involves periapical region of anterior man-  dible, frequently involving more than one tooth at a time  though solitary lesions may be occasionally seen.   These are non-expansile asymptomatic lesions and teeth  in association are invariably vital and are discovered acci-  dently when radiographs are taken for other purposes.    Radiographically, maturation of the lesion can be appreci-  ated, when examined at various stages.   Initially, they appear as periapical radiolucencies,  which can be easily mistaken for a periapical cyst or a  granuloma.   Over a period of time, the mixed radiolucent radiopaque  picture may emerge and as the lesion matures further, even-  tually show dense periapical calcifications at the end stage,  which is surrounded by a narrow radiolucent rim. The lesions  seldom reach beyond 1—1.5 cm diameter and growth is self-  limiting. The lesions remain separated from the periodontal  ligament of the tooth throughout their growth phase.   The histological features are coincidental with radio-  graphic findings and categorised as three stages.   Which shows ample fibrous connective tissue, highly  cellular and with numerous small vessels.    For several years, pathologists were aware of the lesions  occurring in the mandibular posterior region, often occurring  in the tooth-bearing areas and in relation with recently  extracted teeth sockets. Waldron recognised them to be,  localised fibro-osseous cemental lesions, supposedly reac-  tive in nature. The present understanding of these lesions is  hard work of Summerlin and Tomich, besides naming them  as Focal cemento osseous dysplasia, they clinically defined  them for a better understanding and differentiation from  other lesions especially Ossifying Fibroma [31].    Focal osseous dysplasia is more commonly seen in Afro-  Caribbean females. Male to female preponderance is 1:8.  Mainly occurs in the 4th to 5th decades of life with 38 years  being an average age of occurrence.   The lesion appears as painless, non-expansile, localised  condition especially in posterior mandible, both tooth-  bearing areas as well as edentulous mandible where tooth  was extracted in the recent past. A clinical, radiographic and    histopathological differential diagnosis of Focal osseous  dysplasia is Ossifying fibroma. Since both are more common  in posterior mandible and may appear as radiolucent, mixed  or radiopaque, well-circumscribed lesions, the clinical and  radiological differentiation can be confusing provided one  notices the centrifugal growth pattern of and focal osseous  dysplasias barely grow beyond 1.5 cm. Radiographically,  focal osseous dysplasias tend to be well defined with slightly  irregular borders.   On histological examination, one finds connective tis-  sue stroma comprising of loose collagen fibers, inter-  spersed with irregular shaped cementoid calcifications.  Free haemorrhage is noticed throughout, intermixed with  collagen background.    Fic ) OPG ofa  73-year-old Asian female,  who had x-ray taken for  removal of lower right third  molar. X-ray shows diffuse  florid COD-like lesions    Fi )  55-year-old Asian female who  reported for dental extractions  due to pain. Xray reveals  florid COD-like lesions in  both jaws    When the lesions, similar in microscopic and radiographic  appearance to Focal cemento osseous dysplasia, are found in  more than one location in a mandible or in both the quadrants  simultaneously, they are identified as Florid cement osseous  dysplasia. Radiographs displayed a spectrum of sclerotic and  ground-glass opacities limited to alveolar processes but not  to root apices [32]. Chronic osteomyelitis may infrequently  complicate the disease. These cases appear to represent the  most exuberant manifestation of reactive fibro-osseous jaw  disease. Many times, these diseases are an incidental finding  and patient may be asymptomatic (Figs. 30.9 and 30.10)    Florid cemento osseous dysplasia shows predilection for  Afro-Caribbean women in the fourth to fifth decades of life,  with a mean age of 42 years. The lesion has a propensity for  bilateral symmetrical involvement of mandible. Occasional  maxillary involvement is not rare.   The patients are usually edentulous and lesions are usu-  ally non-expansible, if cortical expansion is present then it is  limited in nature.   The diagnosis of Florid OD is mainly clinical and radio-  graphic, Melrose [32] suggests the involvement of two jaw  quadrant is imperative for the diagnosis of Florid  COD. Radiographically, the lesion undergoes stages of  maturation as seen in the other types of OD, initially, the  lesions are mainly radiolucent and with time progressively  become first mixed radiolucent radiopaque and then in  later stages turn into radiopaque sclerotic masses. Simple  bone cyst that appears as sharply defined radiolucent areas  may be intermixed with the lesional tissue, is a frequent  finding in Florid OD. The most commonest radiographic  presentation is of multiple sclerotic lobular opacities  mixed ill defined with radiopaque radiolucent masses  involving the alveolar process of mandible and maxilla  sparing the lower border of the mandible and vertical rami.   Histologically, the lesion has similar features like other  two forms of OD. The lesion specimen consists of cellular  mesenchymal connective tissue, with numerous spindle-  shaped fibroblasts and blood vessels. Multiple haemorrhagic  sites are a common finding in the connective tissue back-  ground along with lamellar-, woven- and cementum-like par-  ticles. Depending on the extent of maturation of the lesion,  they become more sclerotic and the ratio of fibrous connec-  tive tissue to mineralised material decreases.    The modified osseous tissue is prone to infection, hence any  local causes of infection-like periapical pathosis, periodontal  disease, ill-fitting dentures can lead to osteomyelitis of the  underlying altered bone and fistula and sequestra formation. It  is recommended to avoid any surgical intervention for diag-  nostic purposes, as the diagnosis is generally made on clinical  and radiographic presentation. As for the treatment of symp-  tomatic lesions like the presence of underlying osteomyelitis,  conservative care in the form of removal of sequestra and pro-  longed antibiotic therapy is recommended. Extractions are not  recommended for the same reason, as the socket heals by  replacement with cementum-like tissue, which is mainly  avascular.    Surgical intervention in terms of the debulking proce-  dures is only recommended where there is obvious facial  deformity resulting in reduced quality of life [33].    FOLs form a diverse wide spectrum of lesions, which are  still evolving; in their classifications. Maxillofacial surgeons  usually come across intra-oral lesions at various stages and  many of them can be managed easily by routine surgical  modalities. Certain lesions show aggressive nature and  involve mid-face and sino-nasal areas. Such cases will need  a multi-disciplinary approach for optimal treatment out-  comes. Close interaction with the pathologist and adequate  radiological investigations are needed to ascertain the diag-  nosis in many cases. The lack of clarity in classification and  the similar radiological and histological picture of various  lesions add to the difficulty in reaching a diagnosis.    Acknowledgments Suvy Manuel for Figures 30.1, 30.2, 30.3, 30.4,  30.5, 30.6, and 30.9    1. Eversole R, Su L, ElMofty S. Benign fibro-osseous lesions of the  craniofacial complex a review. Head Neck Pathol. 2008;2:177—202.   2. Brannon RB, Fowler CB. Benign fibro-osseous lesions: a review of  current concepts. Adv Anat Pathol. 2001;8:126—-43.   3. Waldron CA. Fibro osseous lesions of the jaws. J Oral Maxillofac  Surg. 1985;43:249-62.   4. Waldron CA. Fibro-osseous lesions of the jaws. J Oral Maxillofac  Surg. 1993;51:828-35.   5. Rajpal K, Agarwal R, Chhabra R, Bhattacharya M. Updated clas-  sification schemes for fibro-osseous lesions of the oral & maxil-  lofacial region: a review. IOSR J Dent Med Sci Ver.   6. Srichinthu KK, Yoithapprabhunath TR, Chitturi RT, Yamunadevi A,  Potsangbam AD, Singh DN. 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Open Access _ This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.  org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropri-  ate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.   The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in  a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.   Vascular anomalies are lesions arising from the arterial and/  or venous and/or lymphatic circulation. These have a wide  array of histological and clinical features and constitute one  of the commonest congenital anomalies in infants and chil-  dren [1].   In the context of iatrogenic creation of arteriovenous fis-  tulas by phlebotomists, William Hunter in the mid-eighteenth  century first described vascular anomalies. Haemangiomas  and vascular malformations are different entities of vascular    anomalies and this was first recognised by James Wardrop in  1818 [2]. In spite of Dr. Wardrop’s work, subjective words  like ‘strawberry hemangioma’ and ‘salmon patch’ were used  for a long time. These terms only reflected the appearance  and did not correlate clinically or histologically [2].   Anomalies presenting in different age groups with vary-  ing clinical behaviours needing different treatments were  often given the same or overlapping names by clinicians.  Commonly used terms are: haemangioma, arterial malfor-  mation, venous malformation, capillary malformation and  lymphatic malformation.    Haemangioma (Figs. 31.1 and 31.20): Is a benign tumour of blood vessels comprising arterioles with endothelial cells,    Fig. 31.1 Non-involuting congenital Haemangioma (NICH) of left cheek ((a) initial therapy with propanolol 10 days post-birth, (b) 6  months following propanolol therapy, (c) excision of lesion at 2 years age)    S. Nair (2) - S. S. Shroff   Department of Oral and Maxillofacial Surgery, Bhagwan Mahaveer  Jain Hospital, Bengaluru, Karnataka, India    © The Association of Oral and Maxillofacial Surgeons of India 2021    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1 -15-1346-6_31    This terminology has been used by many as a common _ often resolve with time. It is necessary for one to be able  term for any vascular anomaly especially in childhood. _ to differentiate between haemangioma and other vascular  These develop within the initial few weeks of life but anomalies.    Arterial malformation (Fig. 31.2): These are dilated, overlapping and tortuous arteries having a coil-like appearance  and/or a collection of arterial loops without any venous component. They are also described as ‘high flow lesions’.    Fig. 31.2 Arterial malformation ((a, b) tongue high flow lesion, (¢) DSA, (d) embolisation)    Fig. 31.3 Left cheek venous malformation ((a) pre-operative Left cheek VM, (b) axial and (c) coronal STIR sequence MRI)    Capillary malformations (Fig. 31.4): These are commonly known as, ‘port wine stain’. It is a flat, well-defined vascular  stain of skin seen early in development when vessels of skin form abnormally which can increase in size and give a  nodular appearance as a late presentation.    Fig. 31.4 Capillary malformation of lower lip, chin and right cheek    Lymphatic malformation (Fig. 31.5a, b): These are lesions containing fluid-filled spaces or channels, thought to be  caused by abnormal development of the lymphatic system.    Fig. 31.5 (a) Micro-cystic lymphatic malformation of tongue ((i) coronal T2 weighted MRI image, (ii) pre-operative clinical). (b) Axial  post-contrast image of macro-cystic lymphatic malformation of left Parotid. Copyright: Authors own publication from IJOMS 2018    Histologically, vascular anomalies are seen as a localised  increase in vasculature with abnormal tortuosity and enlarge-  ment. This is known to be caused by defects in the formation  of these vessels during vasculogenesis [3].    ‘Vasculogenesis’ is defined as growth of vessels from  precursor cells like, haemangioblasts that further give  rise to angioblasts and haemocytoblasts.    Fusion takes place in islands of vasculature leading to the  formation of primary capillary plexus, which then extends and  matures during angiogenesis. This involves the proliferation of  endothelial cells and the recruitment of mural cells to form fully  developed and functional lymphatic and vascular trees [4].   Angiogenesis is regulated by factors like VEGFs (vascu-  lar endothelial growth factors), FGFs (fibroblast growth  factors), PDGF-beta (platelet derived growth factor beta)  and ANGPT-1 and ANGPT-2 (angiopoietins). These factors    cause activation of precursor cells, leading to migration,  proliferation and differentiation of the primary capillary  plexus [5].   VEGFs, angiopoietins, and their endothelial tyrosine  kinase receptors are known to be the central regulators of  vasculogenesis, angiogenesis and lymphangiogenesis [4].   Haemangiomas have currently 2 dominant theories [6],  although unclear. These are:    1. Endothelial cells are formed from deranged placental tis-  sue present in foetal soft tissues during gestation.   2. Stem cells and endothelial progenitor cells which give  rise to haemangiomas, are found in circulation of patients  with haemangiomas.    Abnormal levels of matrix metalloproteinases (MMP9)  and proangiogenic factors (VEGF, b-FGF and TGF-beta 1)  are involved in the pathogenesis of haemangioma. Genetic  errors involving growth factor receptors are also known to  influence the development of these lesions [6].   There are 3 stages in the life cycle of haemangiomas [7],  each characterised by biological markers and processes.  These stages are clinically seen and distinguished micro-  scopically and immunohistochemically [8] as,    1. Proliferative phase—O-1 year of age  2. Involuting phase—1—5 years of age  3. Involuted phase—more than 5 years of age    Fig. 31.6 Arteriovenous malformation of pinna of right ear ((a, b) previous Popescu suturing as reported, (c) coronal CT angiography image, (d)  contrast MR angiography image). Copyright: Authors own publication from IJOMS 2018    Venous malformations (VMs) are known to be autosomally  dominant showing high penetrance. Abnormal venous connec-  tions cause venous congestion, thrombosis and slow expansion  of these lesions. VMs commonly have a sporadic occurrence, but  research has suspected a genetic locus to be involved in their  development [6]. Chromosome 9p has been localised to cause  inherited forms of VMs. The loss of functional mutation on the  angioprotein-receptor gene TIE2/TEK and upregulation of many  factors like tissue growth factor beta (TGF-beta) and basic fibro-  blast growth factor (beta-FGF) is seen [6]. Progesterone recep-  tors are also found in VMs, which explains their propensity to  enlarge rapidly during hormonal changes.   The pathogenesis of capillary malformations (CMs) is  not clearly understood. These can be seen anywhere on the  body, localised to a dermatome or extensive in nature. A  familial pattern has been identified with a locus on chromo-  some 5q in a genome-wide linkage analysis [9].   Lymphatic malformations (LMs) show a focal pattern  of occurrence. The aetiology is not clearly understood.  Although most cases are congenital, there is no evidence of  associated familial pattern. There have been cases of LMs  following trauma or infection. Receptors like VEGFR3 and  Prox-1, likely play a role in their development [10].    The pathogenesis of arterio-venous malformations  (AVMs) is also not clearly understood. A defect in vascular  stabilisation is known to potentially cause AVMs. Intra-  cranial AVM is seen most commonly, followed by AVMs  involving extracranial head and neck, extremities, trunk and  viscera. These are seen at birth and are frequently misdiag-  nosed as a CM or haemangioma. These lesions have been  seen following trauma in adults. Defects in signalling of  TGF-Beta and genetic two-hit hypothesis are the existing  theories [11, 12].    Mulliken and Glowacki [13] in 1982 introduced a biological  classification, which classified vascular lesions into two dis-  tinct entities: haemangiomas and vascular malformations.   Haemangiomas demonstrate endothelial hyperplasia  unlike vascular malformations, which show progressive dila-  tation of abnormal vessels lined by flat endothelium on a thin  basal lamina. A more practical classification amalgamating  their biological behaviour and flow dynamics was later intro-  duced [14] (Table ).    A. Haemangioma  Superficial (Capillary haemangioma)  Deep (Cavernous haemangioma)  Compound (capillary cavernous haemangioma)  B. Vascular Malformations  Simple lesions  Low-flow lesions  Capillary malformations (capillary haemangioma, port-wine  stain)  Venous malformation (cavernous haemangioma)  Lymphatic malformation (lymphangioma, cystic hygroma)  High-flow lesions  Arterial malformation  Combined lesions  Arteriovenous malformations  Lymphovenous malformations  Other combinations    Table 31.2 International Society for the study of Vascular Anomalies  classification system (ISSVA) [15]  Vascular tumors  Benign  Locally aggressive or borderline  Malignant  Vascular malformations  Slow-flow  Capillary malformations  Lymphatic malformations  Venous malformations  Arteriovenous malformations  Arteriovenous fistula  Combined (2 or more VMs in one lesion)  CVM, CLM, LVM, CLVM, CAVM, CLAVM, others  (C-capillary, V-venous, L-lymphatic, AV-arteriovenous)  Anomalies of major named vessels  Vascular malformations associated with other anomalies    This system was later revised and adopted by the ISSVA  [15] Unternational Society for the study of Vascular anoma-  lies). This is currently the most widely accepted and divides  vascular anomalies into: vascular tumors and vascular malfor-  mations (Table 31.2). The online version of the classification, is  available on the ISSVA website (www.issva.org), contains  hypertext links that facilitate the navigation in the classification  and its appendices. These vascular neoplasms show an  increased turnover of endothelial cells, which undergo division  by mitosis, unlike vascular malformations. Vascular malforma-  tions can be capillary, venous, lymphatic and arterial, which  progress in proportion to the child.   We proposed a practical classification of vascular lesions  based on anatomy and depth of location in the head and neck  region [1] (Table 31.3), which helped not only in understand-  ing the extent of lesion but also in determining the surgical  approach and reconstruction necessary. This classification is  found to be most useful for the surgical management of these  complex lesions.    Table 31.3 Anatomical classification of Vascular malformations [1]  (IJOMS 2011: 40)    Type-I lesions (Fig. 31.7) are superficial involving the  epidermis and dermis. These can be excised in toto and  reconstructed with local flaps where necessary. Lasers have  some use in such surface lesions.   Type-II lesions (Fig. 31.8) involve sub-cutaneous tissue  and facial planes. These can be widespread sometimes and  approached by meticulously raising a superficial skin flap.  The lesion is either debulked, excised or corseted as neces-  sary (discussed in surgical management).   Type-III lesions (Fig. 31.9) are deeper involving salivary  glands, usually parotid and sub-mandibular, demand-raising  flaps in sub-cutaneous and sub-dermal planes. The lesion is  either debulked, excised or corseted as necessary (discussed  in surgical management).   Type-IV lesions (Fig. 31.10) involve bone and are either  curetted or excised followed by reconstruction. These are  usually high-flow lesions and require ECA control or endo-  vascular embolisation to achieve adequate haemostasis  (intra-operative dye administration in Fig. 31.10 demon-  strates the efficacy of intra-operative ECA control in treating  such high-flow vascular lesions).   Type-V lesions (Fig. 31.11) involve deeper visceral  spaces like parapharyngeal, retropharyngeal, glottis and  laryngeal. These can be rarely excised intoto and require  access osteotomies of maxilla, mandible or zygoma (see  Chap. 85 on access osteotomies).    A comprehensive and holistic understanding of the true  nature of lesion is important to adequately manage these  patients. The different types will be discussed according to  the ISSVA classification for simplicity here, while the surgi-  cal management will be discussed according to the anatomi-  cal classification, as it was found to be more helpful than  other available classifications.   Superficial haemangiomas (Fig. 31.20) can appear as  raspberry-coloured birthmarks or reddish discolouration of  the skin. The bright red strawberry-like classic appearance  may not be seen in deeper lesions involving sub-cutaneous  tissues. These deep lesions are wrongly diagnosed as vascu-  lar malformation, with normal appearing overlying skin.  Superficial lesions were previously called ‘capillary heman-  giomas’, and deeper lesions “cavernous hemangiomas’.  These terms do not reflect the clinical nature or influence the    Fig. 31.7 Type-I vascular lesion ((a) pre-operative tongue VM, (b) debulking, (c) closure and (d) post-operative). Copyright: Authors own publi-  cations from IJOMS 2011    Fig. 31.8 Type-II vascular lesion ((a) pre-operative Left cheek VM, (b) incision, (c) exposure and excision and (d) Post-operative)    Fig. 31.9 Type-III vascular lesion ((a) pre-operative Left parotid AVM, (b) incision, (c) exposure, (d) facial nerve dissection, (e) excision speci-  men and (f) post-operative). Copyright: Authors own publications from IJOMS 2011    treatment and should be reserved only for histological  description. Compound lesions involving superficial and  deeper tissues are also seen. The clinical appearance may  vary depending on the depth of tumour. Growing haemangi-  omas can show organ involvement and cause ulcerations,  bleeding, hearing problems, vision changes, difficulty in  mastication, dysphagia and dyspnea.   Congenital haemangiomas are further divided into infan-  tile haemangiomas (IHs), rapidly involuting congenital hae-  mangiomas (RICHs), non-involuting congenital  haemangiomas (NICHs) and partially involuting congenital  haemangiomas (PICHs) [15, 16].   IHs are commonly seen in infants and occur in 5—10% of  children [17]. They appear anywhere between a few days to 3    weeks after birth. 80% of these cutaneous lesions are single and  20% are multiple. They grow rapidly and then enter an inactive  phase at about 6 months of age. They then begin to shrink and  involute after 1 year of age and sometimes leave behind a resid-  ual lesion. These residual lesions take longer to resolve.   RICHs (Fig. 31.20) are present at birth and involute by  6-14 months of age. Occasionally, they cause haematologi-  cal irregularities like the Kasabach-Merritt phenomenon  (KMP).   NICHs (Fig. 31.1) are present at birth and get larger with  age. It is best to wait until 1 year of age to differentiate  between RICH and NICH by looking at the involution pat-  tern. PICHs initially present as RICH but fail to involute  completely and remain as NICH.    Fig.31.10 Type-IV vascular lesion ((a) pre-operative AVM right man- injection before occluding of ECA, (e) intra-operative C-arm picture  dible, (b) axial post-contrast CT image, (c) ECA control and injection following dye injection and occlusion of ECA, (f) lesion exposure and  of radiopaque dye, (d) intra-operative C-arm picture following dye (g) currettage of lesion)    Fig. 31.11 Type-V vascular lesion ((a) pre-operative VM left parotid, _ (f) lesion complete currettage, (g) mandibulotomy closure and (h) post-  (b) parapharyngeal extension, (c) coronal Tl weighted MRI image, (d) _ operative). © Association of Oral and Maxillofacial Surgeons of India  exposure, (e) lesion exposure with mandibulotomy and ECA control,    Haemangioma VM’s CM’s LM’s AVM’s KHE’s  Age Birth, few days to Birth Birth Birth, later in life _ Later in life Neonate  3 weeks after birth  Appearance _ Reddish discolouration Bluish Red or purple patch Diffuse swelling _ Pink to bluish -  of skin  Depth Skin, subcutaneous Superficial, deep | Cutaneous only Deep tissues Superficial,deep  —  tissues  Types JH, RICH, NICH ~ Medial, lateral Macrocystic, - -  microcystic  Behaviour Slow growing, Slow growing, Painless, can involve Expansile, Pulsatory, thrill Large, more  involute in 12-14 low flow, local deeper structures infiltrative than 5 cm in  months blood stasis size  Functional Ulceration, vision/ Painful Cosmetic Airway problems, Coagulopathy LIC/ Thrombocyte  problems hearing/swallowing/ — thrombophlebitis, disfigurement, involve pain, dysphagia, DIC, throbbing penia,  airway issues phlebolith other areas like in difficulty in pain, ulceration Kasabach-  formation Sturge Weber mastication Merritt  syndrome, Klippel phenomenon    Venous malformations (VMs) (Fig. 31.3) are most com-  monly seen vascular malformations, which are slow-  growing, low-flow lesions present at birth and demonstrate a  network of serpiginous inter-woven veins. These can grow  extensively, become palpable, discoloured or bluish in colour  with local blood stasis, which sometimes lead to painful  thrombophlebitis. VMs can increase in size, in proportion to  the increase in pressure within vessels caused by valsalva  manoeuvre, dependency, exercise or agitation. VMs are usu-  ally compressible on palpation. They can demonstrate “phe-  boliths’, which are nothing but small calcifications formed  due to, prolonged intra-vascular coagulation (Fig. 31.12).   Phleboliths are the commonest cause of pain in VMs.  There is progressive lamellar fibrosis following intra-  vascular thrombus formation. Calcium phosphate and car-  bonate are deposited in the core of the thrombus with  peripheral mineralisation [18], which slowly increases in  size. They are clinically palpable intra-orally, bi-manually in  the cheek and over bony prominences. These are present as  multiple oval or round laminated bodies (Fig. 31.12) with  radiolucent or radiopaque corners, radiologically. Phleboliths  can be areas of resistance to injecting sclerosants and should  be excised separately.   Capillary malformations (CMs) (Fig. 31.4), can be seen  in the neonatal period and should not be mistaken with infan-  tile haemangiomas (IHs). They occur in around 0.3% of chil-  dren presenting with vascular anomalies. CMs _ usually  present congenitally as a flat, red or purple cutaneous patch  with asymmetric borders. They are painless and do not bleed  spontaneously. They are categorised as ‘medial’ or ‘lateral’  lesions, based on their location in head and neck. Lateral  lesions involve areas of face along the distribution of trigem-  inal nerve. They present as portwine stains, usually increase  in size to involve deeper sub-cutaneous tissues causing the  lesions to become darker, more raised and nodular. CMs may    be part of a syndrome, commonly the Sturge-Weber syn-  drome, which is characterised by CM involving the ophthal-  mic branch of trigeminal nerve, leptomeningeal angiomatosis  and choroid angioma. CMs may also be seen in the Klippel-  Trenaunay syndrome with multiple vascular (lymphatic,  venous and capillary) abnormalities.   Lymphatic malformations (LMs) (Fig. 31.5) are usually  congenital and not always detected until later in life. LMs are  slow-flow lesions and can be macro-cystic (>2 cm)  (Fig. 31.5b), micro-cystic (<2 cm) (Fig. 31.5a) or mixed,  depending on the size of predominant cysts within them.  Macro-cystic LMs can show expansion and compression of  adjacent anatomical structures in the head and neck causing  dysphagia, dyspnea and masticatory problems. Micro-cystic  LMs were previously called lymphangiomas and demon-  strate an infiltrative nature. LMs with local haemorrhage and  infection can cause significant pain. LMs of the head and  neck are further described by the de Serres classification  scheme [19], which classifies disease severity based on the  location and prognosis.   Fast-flow arterio-venous malformations (AVMs)  (Fig. 31.6), usually present with a pulsatile local swelling.  These AVMs along with some slow-flow lesions are at an  increased risk of haematological complications like coagu-  lopathies due to disturbances in haemostasis and thrombosis.  Blood pools in abnormal slow-flow vessels, resulting in acti-  vation of the coagulation system, resulting in a process  known as ‘localized intravascular coagulopathy’ (LIC),  which shows low fibrinogen, elevated D-dimer levels and  mild thrombocytopaenia. This can further cause, ‘dissemi-  nated intravascular coagulopathy’ (DIC) and consumption of  various coagulation factors.   AVMs are known to behave aggressively in later life,  which can be stimulated by pubertal changes, pregnancy or  trauma. They may present with throbbing pain, ulceration    Fig. 31.12 Left cheek and lower lip VM ((a) clinical picture, (b, ¢) post-contrast axial and sagittal CT images showing multiple phleboliths)    and bleeding. Significant bleeding can sometimes be a cause  of cardiac failure, in affected individuals.  A useful clinical staging system was introduced by  Schobinger [20] in 1990. This system is widely used for  describing the clinical presentation and evolution of AVMs:  Stage I (quiescence): pink-bluish stain, warmth and arterio-  venous shunting by way of Doppler examination  Stage II (expansion): same as stage I, plus enlargement, pul-  sations, thrill, bruit and tense/tortuous veins   Stage IIT. the same as stage II, plus dystrophic skin changes,  ulceration, (destruction) tissue necrosis, bleeding or per-  sistent pain   Undiagnosed AVMs of bone are occasionally the cause of  increased bleeding during/after extraction of teeth in a dental  office, which can lead to life-threatening airway and haema-  tological problems if not treated immediately (Fig. 31.13).  These warrant urgent transfer to a hospital and embolisation  or ECA control.   Hereditary haemorrhagic telangiectasia (HHT) is autoso-  mally dominant and presents with the formation of expand-  ing arterio-venous fistulas. These patients usually present  with superficial (skin, mucosal) or deep (visceral) telangiec-  tatic lesions. They may sometimes present with aneurysms  causing epistaxis or intra-cranial haemorrhage.   Kaposiform haemangioendotheliomas (KHEs) are large  lesions (greater than 5 cm), which are present in the neonatal  period. They are extremely rare and have a low incidence of  occurrence. Hence, there are no clear guidelines on their  management. These are aggressive vascular tumours, which  can be complex in their management due to thrombocyto-  paenia secondary to platelet trapping. This phenomenon is  known as KMP (Kasabach-Merritt phenomenon). 70% of  patients with KHEs demonstrate this phenomenon [21].    Clinical and radiological assessment go hand in hand to  accurately diagnose and manage these diverse groups of  head and neck vascular anomalies. Selection of the imaging  should be tailored according to the indication, advantages,  disadvantages and availability of resources. Good knowl-  edge of all the available radiological modalities is essential  to treat these lesions.   Computed tomography (CT) with contrast  Digital subtraction angiography (DSA)  Magnetic resonance imaging (MRI)    US (Fig. 31.14) is the least invasive modality of imaging  available for assessment of vascular anomalies. It is used as  a baseline investigation for superficial head and neck vascu-  lar lesions. In addition to the above, the US has a high sensi-  tivity in diagnosing these lesions. The disadvantages of the  US are its limitation in detecting deeper soft tissue and bony  lesions.   Doppler ultrasound (Fig. 31.15) is used to demonstrate  high-flow lesions. Flow towards the ultrasound transducer is  seen in red and away from the transducer seen in blue. The  arterial feeder is usually identified by increased colour flow,  high doppler shift and low resistance.   CT (Fig. 31.16) is used to diagnose bony lesions, provide  cross-sectional details and detect the presence of calcifica-  tions like phleboliths in venous malformations and haeman-  giomas. Most scans can be done in less than a minute with  quick acquisition time. Reduced imaging time and low cost  compared to MRI make contrast CT widely used for diag-  nosing soft tissue vascular lesions. Surveillance imaging  with CT is not recommended due to increased exposure to  ionising radiation.   MRI (Fig. 31.17) is the most preferred and accepted  imaging for diagnosing and monitoring soft-tissue vascular  lesions of head and neck. Its superior contrast resolution, in-  depth soft-tissue assessment and non-exposure to ionising  radiation, makes it the investigation of choice for these  lesions. Haemangiomas and VMs show intense enhancement  with MRI. AVMs and LMs show minimal enhancement.   Fat-suppressed T2-weighted imaging is used to discrimi-  nate these lesions among each other. Intense T2-weighted  signal is seen with VM’s and macro-cystic LM’s due to cys-  tic spaces within them and pooling of slow-flowing blood or  lymph. Moderate signal intensity is seen with haemangiomas  and vascular neoplasms due to their cellular composition.  Mild T2-weighted signal is seen with AVM’s reflecting tis-  sue oedema.   Long acquisition time (at least 30 min) and increased cost  of imaging limit its use [22]. Use of sedation or anaesthesia  is required for infants, children and uncooperative adults.   Angiography (Fig. 31.18) is usually reserved for thera-  peutic endovascular interventions. Angiography includes  arteriography, venography and injection of direct intra-  lesional contrast agent. This provides good resolution (spa-  tial and temporal) of the vascularity and also permits  catheter-induced percutaneous therapy. Arteriography is  used for the evaluation of high-flow vascular lesions. Its use  is limited due to the invasive nature and use of ionising  radiation.   DSA (Fig. 31.19) should be reserved for patients under-  going endovascular treatment. DSA is used for diagnosis of  AVMs where the feeding artery, draining vein, nidus con-  necting artery and vein can be clearly imaged [23] and simul-  taneous embolisation can be performed, by an interventional  radiologist.    Fig. 31.13 Bleeding following dental extraction—Extracorporeal cur- _ poreal currettage and excision of diseased bone and (e) fixation of man-  rettage of high-flow bony vascular lesion and fixation of mandible ((a) _dible as the free graft)  pre-operative, (b) intra-oral, (c) ligation of main feeder, (d) extra-cor-    Multi-planar dynamic contrast-enhanced MRI is pre-  ferred for extensive vascular malformations of the head and  neck, especially in lesions involving aerodigestive tract, neu-  ral and vascular structures.    Fig. 31.18 AVM of right mandible ((a) Contrast MR angiography image, (b) T2-weighted MRI image). Copyright: Authors own publications  from IJOMS 2011    Fig. 31.19 AVM left cheek ((a) clinical image, (b) DSA image during embolization)    Correct diagnosis is important for selecting the appropriate  therapy for vascular anomalies.    The aim of managing complex vascular lesions should  be to relieve acute symptoms like pain, swallowing and  airway problems, prevent and treat thromboembolic  events and correct the cosmetic impairment caused by  them.    The type of vascular anomaly and its flow characteris-  tics, determine the mode of management.    Congenital haemangiomas, low flow venous malforma-  tions and lymphangiomas can be considered for treatment    with systemic and sclerotherapy. Residual and large lesions  are usually treated with surgery. AVM’s and high-flow mal-  formations have been mostly treated using embolisation with  or without surgical excision/debulking successfully.   The author’s wide experience in the surgical management  of most low- and high-flow lesions has provided acceptable  and predictable results.   In haemangiomas, a ‘wait and observe’ strategy is pre-  ferred. Involution is seen in more than 85% of patients. If a  malignant lesion is suspected, a biopsy with a request for  GLUT-1 immunostaining is required to confirm its true  nature [24]. Active intervention is considered if the lesion is    Propranolol (Fig. 31.20) is the first line of treatment and  is best to involve a paediatrician to monitor the dosage and  systemic complications associated with it. Propranolol  causes vasoconstriction and possibly reduced expression of  pro-angiogenic factors of the haemangioma growth phase,  leading to apoptosis of capillary endothelial cells.   Treatment during the proliferating phase is given to prevent  impending functional or aesthetic complications especially    Fig. 31.20 Rapidly involuting congenital Haemangioma (RICH) of right face treated with propanolol therapy ((a) pre-treatment, (b)    near vital areas like eyes and ear. In the absence of contra-indi-  cations to propranolol like sensitivity to beta-blockers, bron-  chospasm, hypotension or bradycardia and after having a  routine haematological and biochemical assessment by the  paediatrician, a dose of | mg/kg/day in three divided doses may  be initiated and titrated up to 2 mg/kg/day. This is given for 12  months or longer according to the response. Meticulous dose  adaptation is important to prevent adverse effects. These could  be bradycardia, increased airway resistance, bronchial obstruc-  tion and hypotension.Long-term effects of propranolol are still  not known and other drugs like timolol have been tried for  superficial and peri-ocular lesions. Invasive therapies are  almost never required to treat these lesions.   Although propranolol has replaced the use of systemic  steroids as the first line therapy for haemangiomas, intra-  lesional therapy for localised lesions with, Triamcinolone  may be used with a dose of 2 mg/kg every 4-6 weeks depend-  ing on the response. It is known that one-third of patients do  not respond to treatment with steroids. Systemic steroids are  sometimes given in conjunction with propranolol after con-  sulting with the paediatrician.   Rebound growth being a problem with systemic therapy  using propranolol and/or steroids, the dose is always pre-  ferred to be tapered-off before discontinuing following reso-  lution of the lesion.   Embolisation is considered in patients with high-output  cardiac failure and large-aggressive lesions causing prob-  lems with haemostasis.   Surgery is considered between 2 and 4 years of age after  having attempted medical treatment to minimise deformity  involving eyes, nose and lips and other areas of face.   Pulsed dye laser was used in past for coagulating the sur-  face of ulcerated lesions. This is now used for the treatment  of surface residual telangiectasia, usually after 10 years of  age (Algorithm 31.1).   Minimally invasive percutaneous sclerotherapy is used  widely for the treatment of venous malformations. A wide range  of agents are known to be used in the literature. There is no  consensus on choice of sclerosant to be used. Commonly used  sclerosants [25] are pingyangmycin (PYM), absolute ethanol,  OK-432 (picibanil), ethanolamine oleate, bleomycin, polidoca-  nol, doxycycline and STS (Sodium tetradecy] sulphate).   PYM [25], also known as Bleomycin A5, is the most  commonly used single-drug therapy for the treatment of cer-  vicofacial malformations. Transient fever and swelling are  commonly seen side effects. Skin ulceration and sub-  cutaneous tissue atrophy are scarcely seen complications.   Absolute ethanol [25] causes alteration in cellular pro-  teins and hence damages the endothelium of the vascular  wall leading to obliteration of its lumen. Common complica-  tions include, nerve injury, necrosis and ulceration of skin.   OK-432 [25] is a lyophilised preparation of low-virulence  bacteria, group A Streptococcus pyogenes, incubated with    benzyl- penicillin. It causes, induction of various cytokines.  The inflammatory response caused by this remains localised  and causes endothelial damage. The complications include  local swelling and transient facial nerve palsy.   Ethanolamine oleate [25] is an emulsion of fatty acids,  which induces thrombosis and damages the endothelium.  Complications like ulceration and necrosis of skin are known  but infrequently observed.   Bleomycin [25] was first used in the treatment of cystic  hygromas (now lymphatic malformation). It is now used  widely for management of lymphatic and venous malforma-  tions. It inhibits DNA synthesis and has a non-specific  inflammatory reaction on the endothelial cells. Adverse  effects of bleomycin are minimal and transient, mostly being  localised pain and swelling. Skin infections in the area of  injection are seen less commonly. Some people report with  occasionally severe nausea.   Polidocanol [25] is a non-ionic detergent, causes absorp-  tion at the cell membrane and leads to lysis of endothelial  lining. Superficial necrosis of skin or mucosa is a known  complication with Polidocanol.   Doxycycline [25] belongs to the tetracycline group of  antibiotics. Its mode of action is not yet clear, but its effects  are known to be due to inhibition of matrix metalloprotein-  ases and cell proliferation. It also causes suppression of vas-  cular endothelial growth factor during angiogenesis and  lymphangiogenesis. This further leads to dense adhesions  and fibrosis due to collagen and fibrin deposition. Macro-  cystic LM’s show a better response to treatment with  doxycycline in comparison to micro-cystic LM’s.  Haemorrhage, cellulitis, pain and transient oedema are com-    monly seen complications. Scarring, skin excoriation and  horner syndrome are seen less commonly. These adverse  effects are self-limiting and likely to be related to the scleros-  ing effect rather than a side effect of the medication itself.  STS [25], also known as sotradecol, causes denaturation  of proteins like clotting factors due to disruption of the nor-  mal architecture of the lipid bilayer in cell membranes of  endothelial cells. This causes fibrosis and occlusion of ves-  sels. It is not known to have any major complications so far.  Lymphatic malformations are treated depending on the  type and location in head and neck. As mentioned previ-  ously, these lesions can cause pressure on the airway,  aerodigestive tract and enlarge due to repeated infection or  haemorrhage into the lesion. In the majority of patients  with macro-cystic LMs, sclerotherapy with Picibanil (OK-  432) has shown good results. Patients may develop inflam-  mation at the site of injection and fever, which is managed    symptomatically. Micro-cystic LMs may require systemic  therapy with Sirolimus or surgery as they do not always  respond to Picibanil. Sirolimus is a natural macrolide  secluded from Streptomyces genus (Streptomyces hygro-  scopicus). It causes a decrease in the vascular endothelial  growth factor (VEGF) and is a key regulator in lymphan-  giogenesis and angiogenesis.   Bleomycin is used widely for the treatment of VMs and  microcystic LMs. The mechanism of action on micro-cystic  disease is not completely understood and may involve derange-  ment of tight junctions between endothelial cells or induction  of endothelial mesenchymal transition. The overall response is  favourable but complete response is seen in only about 20-57%  [25]. The author follows a protocol of intralesional injection of  15 IU Bleomycin in 5 ml of fresh normal saline, administered  every 15 days. Most patients show a response in 3-4 sittings  (Fig. 31.21). Lymphatic malformations are known to cause sec-    Fig. 31.21 Venous malformation-Left cheek ((a) before sclerotherapy, (b) after sclerotherapy, (c) pre-treatment T2-weighted MRI image)    ondary skeletal deformities, which are addressed due to func-  tional or cosmetic reasons as necessary.   AVMs are the most challenging type of vascular malfor-  mations to manage due to their aggressive nature. They tend  to cause progressive facial deformity and pose a significant  systemic risk. They are high-flow lesions that typically dem-  onstrate a nidus with arterial feeders, arteriovenous connec-  tions and enlarged veins. Schobinger’s class II and IV  demand aggressive management with combined embolisa-  tion, surgical excision and reconstructing the residual defect.  Trans-arterial and trans-venous catheter angiography are  commonly used for assessment, examination of the nidus  and location of arterio-venous shunting. A few lesions can be  controlled with frequent embolisation. The nidus must be  treated to get control over the lesion. Catheter embolisation  causes obliteration of the nidus in order to prevent a further  increase in size and haemorrhagic complications. This can  be either endovascular (Fig. 31.22) as used for large AVM’s  with aberrant feeders or percutaneous (Fig. 31.23) used for  more superficial lesions. The feeders are sequentially  embolised from distant to proximal feeders. Embolisation  can be used for pre-surgical occlusion of feeder vessel on the  same day of planned surgery to minimise intra-operative  blood loss.    Kaposiform Haemangioendotheliomas (KHEs) are  treated with hematological agents such as vincristine, ste-  roids or sirolimus. These systemic medications help in the  resolution of KHE and associated KMP (Kasabach Merritt  phenomenon). Surgical management of these lesions is usu-  ally not required but small lesions can be removed in toto  with early intervention.    Unlike in the past, most low- and high-flow vascular anoma-  lies are amenable to surgical management by either excision  or debulking. Smaller-sized lesions are almost always excised  completely. In contrast, larger-sized lesions are mostly deb-  ulked and need multiple procedures. External carotid artery  (ECA) control is used to have reasonable control before and    during procedures involving high-flow lesions. This is partly  because of collateral blood supply from the opposite side.   For simplicity, the author’s own anatomical classification  is followed as it makes the understanding of the surgical  approaches and the rationale behind them more lucid and  comprehensible. Also, the concept of “Corset suturing’ will  be explained, which has been proved to be an asset in man-  agement of large low-flow vascular anomalies.    An understanding of the different layers and planes of dis-  section in the head and neck is important to approach and  treat these vascular anomalies. The commonest areas  involved in the head and neck are cheek, lower and upper  lips, eyelids, pre-auricular, mandible, submandibular,  submental, upper neck, posterior and lateral oropharynx.  The glottis, sub-glottis and lower neck are less commonly  involved. Lymphovascular malformations are seen occupy-  ing scalp and orbit commonly.   Layers of face from superficial to deep are—skin, subcu-  taneous tissue, SMAS layer, parotid fascia (pre-auricular)/  deep cervical fascia (sub-mandibular), salivary gland (parotid  and sub-mandibular regions), muscle, periosteum and bone.  The scalp has a loose areolar plane and all other tissues  attached. The neck has vital structures like the carotid artery,  jugular vein, spinal accessory nerve, cervical plexus and  other muscles superficial and deep to them.    According to the author’s classification, vascular malforma-  tions were categorised into five types based on their anatomy  and depth of location in the head and neck. This is a good  guide for selecting the type of surgical management and  reconstruction.    e In type-I, superficial lesions require excision of skin or  mucosa. Local or regional flaps have been used in recon-  struction of the residual defect.   e Type-II, sub-mucosal lesions require complete excision  after elevation of skin flaps.   e Type-II, lymphovenous malformations or venous mal-  formations involve salivary glands and are excised along  with the affected gland.   ¢ Type-IV, intra-osseous lesions require excision with  removal of involved bone and reconstruction of the resid-  ual defect as necessary.    Fig. 31.22 Sequential endovascular embolisation of left cheek AVM ((a—d) progressing blockage of blood supply to AVM, (e) 3D reconstructed  view of the vascular network)    Fig. 31.23 AVM of left supra-orbit ((a) pre-operative, (b) CT with contrast, (c) percutaneous embolisation, (d) Surgical excision via haemicoro-  nal approach, (e) post-operative)    e Type-V lesions involve deep visceral spaces, such as the  parapharyngeal or infra-temporal fossa and usually  require mandibular access osteotomy for complete expo-  sure and complete removal of the lesion.    The above procedures can demand either endovascular  embolisation, intra-lesional embolisation or ECA control  prior to attempting excision or debulking of these lesions.    The ECA of the involved side is exposed through a cervical  incision, which often forms, part of the access for removal of  the malformation. The sternocleidomastoid muscle is  retracted posteriorly at the level of the greater cornu of the  hyoid bone, exposing the carotid sheath. The external carotid  distal to the carotid bifurcation is identified. The vessel is  snared with a vascular sling passed through a rubber catheter.  Gentle strangulation of the vessel can be accomplished by  advancing the catheter. This additional compression of the  vessel serves to reduce blood flow to the lesion. In demand-  ing situations, the ECA can be ligated. Many times due to  risk of collateral blood supply to these lesions, ECA control  is an adjunct to achieving haemostasis along with aggressive  local control.    Corset suturing [26] is a proven technique in management of  large low-flow venous malformations of head and neck, espe-  cially in lesions where complete excision is not practically  possible and also those in close proximity to important struc-  tures like airway, facial nerve, spinal accessory nerve, internal  jugular vein and in medically compromised individuals.   ‘Corset’, is a garment worn to hold and train the torsoin to  a desired shape for aesthetic or orthopaedic purposes. The  procedure employed is raising a flap in the sub-SMAS or  sub-cutaneous plane depending upon the type of lesion fol-  lowed by placement of a bioresorbable suture (polydiaxa-  none) that runs in a continuous vertical looping fashion from  sub-cutaneous to deep layer and from one end to another,  incorporating the lesion within the suture. The suturing is  advanced at regular and equidistant intervals to involve the  bulk of lesion resulting in compression of the vascular spaces  and causing obstruction of the afferent and efferent vessels.  This reduces the risk of bleeding, swelling and size of lesion.  The blood supply gets interrupted due to obstruction of affer-  ent vessels. In large lesions, this suturing should be done par-  allel to each other covering the whole lesion from superior to  inferior and medial to lateral, which would occlude the  regional vascular channels, interrupting and obstructing the  blood circulation in the tumour. These sutures must be tight-  ened cautiously, slowly and progressively to achieve gradual  and complete strangulation of vascular channels until com-  plete closure of their lumen is assured. This procedure  decompresses the lesion completely and reduces the risk of  post-operative haemorrhage. The excess skin flap is excised,  drains are secured followed by primary closure. The final  scar is fairly acceptable, as all incisions are originally placed  within the skin tension lines.    Superficial Type-I (Fig. 31.7) lesions mostly derive from the  reticular dermis and is treated with direct excision and clo-  sure or local-flap reconstruction. Care is taken to place  incisions along the skin tension lines of the face and neck to  avoid unaesthetic results. It is challenging to select these  lines in young individuals and every attempt is made to lay  these incisions on prominent skin creases like nasolabial,  mentolabial, pre-auricular and lower skin crease of neck.  Type-II (Fig. 31.8) lesions are approached by raising skin  flaps using the following incisions, commonly—pre-  auricular with either neck skin crease extension or temporal  extension, neck crease incision alone, nasolabial skin crease  incision, mid-face Weber-fergusson incision and coronal  approach. Every attempt is made to maintain a sub-SMAS    Fig. 31.25 Venous malformation right face, lower lip ((a) pre-operative, (b) post-operative, (c) lesion exposure and (d) corset suturing of lesion).    plane but vascular anomalies being composite in nature can  demand modifications. There is always a risk of thinning the  skin flap excessively and care should be taken to avoid but-  ton-holing and avoiding avascular necrosis. The lesion is  excised completely or debulked depending on the size.  Corseting is used for large low-flow malformations as  described above.   Tongue lesions are mostly excised in toto or debulked in a  V shaped fashion to achieve primary closure.    Type-II (Fig. 31.9) lesions are approached the same way  as Type-II. Being deeper in nature, the gland is sacrificed  with some risk of permanent facial nerve damage. Use of  ‘corseting’ in these cases has shown good results with com-  plete recovery of facial nerve weakness over a period of |  year.   Type-IV (Fig. 31.10) lesions like other types are rarely  seen on their own and are usually in combination with Type  I, Il or V. These lesions are treated with curettage or segmen-    tal resection of bone followed by reconstruction (Fig. 31.13).  There are reports of extra-corporeal curettage of segmentally  resected lesions and re-fixation to maintain bone continuity.   Type-V (Fig. 31.11) lesions commonly require access to  osteotomies like mandibulotomy, segmental or complete  Lefort-I, rhinotomy or zygomatic swing osteotomies to gain  adequate access. The lesions are uncapsulated and rarely  excised completely but improve the quality of life and reduce  risk of mortality due to airway obstruction and haemorrhage.  In the authors’ experience, use of corseting has proven to be  beneficial in these cases.   Excess skin flap is always excised to give a near normal  appearance. Use of an adequate number of drains and metic-  ulous haemostatic closure is imperative to achieve accept-  able and aesthetic results.   Most large lesions require further excision and debulking  procedures as the age advances until growth is achieved.  Large low-flow lesions have potential to be excised com-  pletely secondarily, following prior corset suturing.    Vascular lesions can have complications ranging from none  (like in haemangiomas) to bleeding, ulcerations and infec-  tion. Superficial lesions and ulcerations benefit with the use  of pulsed-dye laser. Bleeding can usually be managed with  compression dressings.   Large venous and lymphatic malformations can cause  local swelling, pressure effects on trachea and oesophagus,  pain and infection, demanding immediate treatment like  embolisation or surgical debulking along with control of air-  way and infection.    DSA +/- Embolisation or  Embolisation followed by surgical  excision/debulking under ECA control  +/- Reconstruction with local/pedicled/free flaps    The two common complications of LMs are bleeding  within the lesion and infection. Bleeding can be seen sponta-  neously or as a result of trauma. This further causes immedi-  ate and painful enlargement of the lesion with associated  ecchymosis. Analgesia and observation usually suffice for  symptomatic management. Prophylactic antibiotics can be  given in the case of profuse bleeding. Long-term intra-  venous broad spectrum antibiotics may be necessary cover-  ing pathogens of head and neck, especially in high-risk  patients. Haemorrhage and infection can sometimes trans-  form a macro-cystic lesion into a micro-cystic type with  associated scarring. LMs are known to increase in size in the  presence of a viral or bacterial infection. This is usually self-  limiting and thought to be due to changes in the lymphatic  flow. Bacterial superinfections can be fatal causing ascend-  ing cellulitis and septicaemia. Any infection in cervicofacial  LMs can cause obstruction of the upper airway and oesopha-  gus causing dyspnea and dysphagia.   Incompletely treated AVMs tend to recur and continue to  grow. They should not be underestimated.    Micro-cystic lymphatic malformations have always been chal-  lenging cases to be treat, especially involving extra- and intra-  cranial areas of head and neck. Currently available treatments  have limited effectiveness and high risk of complications.  Techniques using lymphography and idiocyanine green have  been used to locate the exact location of afferent and efferent  lymphatic flow and performing a lymphatic-venous anasto-  mosis has been described in treating these lesions [27].  Vascular-disrupting agents (VDA’s) [28] are a group of  ‘vascular targeting’ agents that show selective activity  against tumour vascular networks, causing severe obstruc-    tion in their blood flow and subsequent necrosis. These  have been investigated for a long time but haven't yet  actively been used in the treatment of vascular lesions of  the head and neck. Micro-tubule-depolymerising agents are  the largest group of small molecular weight VDAs, which  include lead compound disodium combretastatin A-4  3-O-phosphate (CA-4-P) [28], and are under clinical devel-  opment for cancer. VDAs can also interfere with angiogen-  esis and can be potentially used as novel drugs for the  treatment of conditions with excessive angiogenesis, in  addition to cancer.   3D remodelling and bioprinting of areas affected by vas-  cular anomalies with their feeder vessels are under study, for  training and familiarising one with possible complications  during procedures like embolisation and surgery.    Vascular anomalies are a diverse group of lesions requiring  knowledge and skill to identify, accurately diagnose and  treat adequately. Most of these lesions present as a com-  plex problem with a combination of different types and  other systemic complicating features. This demands a  multi-disciplinary team comprising maxillofacial surgeon,  vascular surgeon, pediatrician, reconstructive surgeon,  anaesthetist and speech and language therapist with exten-  sive training, understanding and experience to tailor an  appropriate treatment plan. Selection of sclerosants should  be with caution to minimise their side effects. Surgery has  an important role in achieving quicker and long-term sta-  ble results in most cases.    1. Nair SC, Spencer NJ, Nayak KP, Balasubramaniam K. Surgical  management of vascular lesions of the head and neck: a review of  115 cases. Int J Oral Maxillofac Surg. 2011;40:577-83.   2. Mulliken JB, Young AE. Vascular birthmarks. Hemangiomas and  malformations. Philadelphia: Saunders; 1988.   3. Brouillard P, Vikkula M. Vascular malformations: localized defects  in vascular morphogenesis. Clin Genet. 2003;63:340.   4. Lohela M, Bry M, Tammela T, et al. VEGFs and receptors involved  in angiogenesis versus lymphangiogenesis. Curr Opin Cell Biol.  2009;21:154.   5. Boon LM, Ballieux F, Vikkula M. Pathogenesis of vascular anoma-  lies. Clin Plast Surg. 2011;38:7-19.   6. Richter GT, Friedman AB. Hemangiomas and vascular mal-  formations: current theory and management. Int J Pediatr.  2012;2012:645678.    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Ethunandan M, Mellor TK. Hemangiomas and vascular malfor-  mations of the maxillofacial region—review. Br J Oral Maxillofac  Surg. 2006;44:263-72.   ISSVA Classification of Vascular Anomalies ©2018 International  Society for the Study of Vascular Anomalies Available at “issva.  org/classification”.   Kilcline C, Frieden IJ. Infantile hemangiomas: how common  are they? A systematic review of the medical literature. Pediatr  Dermatol. 2008;25(2): 168-73.   Mohan RPS, Dhillon M, Gill N. Intraoral venous malformation  with phleboliths. Saudi Dent J. 2011;23:161-163).   de Serres LM, Sie KC, Richardson MA. Lymphatic malformations  of the head and neck. A proposal for staging. Arch Otolaryngol  Head Neck Surg. 1995;121(5):577-82.   Kohout MP, Hansen M, Pribaz JJ, Mulliken JB. Arteriovenous mal-  formations of the head and neck: natural history and management.  Plast Reconstr Surg. 1998; 102(3):643—54.   Croteau SE, Liang MG, Kozakewich HP, et al. Kaposiform heman-  gioendothelioma: atypical features and risks of Kasabach-Merritt  phenomenon in 107 referrals. J Pediatr. 2013;162(1):142-7.  Steinklein JM, Shatzkes DR. Imaging of vascular lesions of head  and neck. Otolaryngol Clin N Am. 2018;51:55-76.   Baek HJ, Hong JP, Choi JW, Suh DC. Direct percutaneous alcohol  sclerotherapy for venous malformations of head and neck region  without fluoroscopic guidance: technical consideration and out-  come. Neurointervention. 2011;6:84—8.   Hoff SR, Rastatter JC, Richter GT. Head and neck vascular lesions.  Otolaryngol Clin N Am. 2015;48:29-45.   Horbach SER, Lokhorst MM, Saeed P, de Goiiyon Matignon de  Pontouraude CMF, Rothova A, van der Horst CMAM. Sclerotherapy  for low-flow vascular malformations of the head and neck: A sys-  tematic review of sclerosing agents. J Plast Reconstr Aesthet Surg.  2016;69:295-304.   Nair SC, Chawla JP, Shroff SS, Kumar B, Shah A. Corseting: a  new technique for the management of diffuse venous malforma-    tions in the head and neck region. Int J Oral Maxillofac Surg. 28. Kanthou C, Tozer GM. Microtubule depolymerizing vascular dis-   2018;47(12):1534—40. rupting agents: novel therapeutic agents for oncology and other  27. Kato M, Watanabe S, lida T, Watanabe A, Megumi F. Peri-orbital pathologies. Int J Exp Pathol. 2009;90:284—94.    Open Access This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.  org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropri-  ate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.   The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in  a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.    The Face is a mirror of what we are from inside. It is like an  opera that reveals a person’s inner self, nature, personality  and health. The signs and symptoms of age, illness, defi-  ciencies and personality traits show on our faces. A lot can  be postulated by just observing the different facial expres-  sions of a person. A minuscule defect on the face engraves  an exaggerated long-lasting impression on a person’s mind  and soul.   Ageing is a process which cannot be defied. With the pas-  sage of time, every individual goes through a phenomenon of  complex transformations which takes away the youthfulness.  The various signs of ageing seen on the face include reces-  sion of hairline, wrinkles on the forehead, drooping of the  upper eyelid, hollowness in the under-eye area, deepening of  nasolabial fold, folds on the face, sagginess of skin at the  border of mandible, etc. (Fig. 32.1). Today, with the chang-  ing cultures and requirements in the profession, every indi-  vidual wants to look better than what he or she is.   As the saying goes “Beauty has no age”, more and more  elderly people also want to have their face rejuvenated. So,  today we have a range of patients of vast age variations who  want to have a more rejuvenated look. The various modali-  ties for rejuvenating the ageing face require fine skill and  artwork combined with scientific knowledge and under-  standing of the whole face including scalp, forehead, perior-    Electronic Supplementary Material The online version of this chap-  ter (https://doi.org/10.1007/978-98 1-15-1346-6_32) contains supple-  mentary material, which is available to authorized users.    A. K. Panda   Department of Oral & Maxillofacial Surgery,  SD Dental College and Hospital, Parbhani, Maharashtra, India    A. Chowdhary  Department of Periodontology, SD Dental College and Hospital,  Parbhani, Maharashtra, India    © The Association of Oral and Maxillofacial Surgeons of India 2021    bital area, perioral area, neck, etc., so as to achieve a more  youthful appearance.   Time and technology has evolved. For many years the  standard had been chemical peels as the non-invasive proce-  dure to facelift as the invasive modality for face rejuvenation.  Today, we have a vast range of procedures and technologies  to counter ageing phenomenon and provide a rejuvenated  appearance. We shall discuss the various non-surgical  modalities in this section which physicians are adopting to  treat patients with a wide range of Facial Aesthetic  concerns.   The ageing of human face is a highly complex, irrevers-  ible and progressive biologic phenomenon that occurs with  the ticking of time. The main factors leading to facial ageing  include gravity, bone remodelling, subcutaneous fat redistri-  bution and loss, hormonal imbalance, chronic sunlight, pol-  lution and smoking. Other environmental factors that  allegedly affect facial appearance include mental stress,  nutritional deficiencies, work habits, drug abuse and disease.  This dynamic process is a synergistic effect of various fac-  tors and actually takes place at 4 distinct levels (the 4 S lev-  els): Skin, Subcutaneous tissue, SMAS and facial Skeleton.    The epidermis contains keratinocytes and dead corneocytes.  The basal cells at the stratum basal divide to form keratino-  cytes, produce keratins and drift upwards as they mature. By  the time keratinocytes reach the most superficial layer, they  lose their nucleus and cytoplasmic organelles and are known  as corneocytes. In a total period of 40-50 days, the keratino-  cytes come to the surface and corneocytes exfoliate. This  time taken for the process of keratinisation, that is matura-  tion of keratinocytes along with shedding of corneocytes, is  known as the turnover time.   The natural process of desquamation sheds off the dry,  old, hardened skin cells and gives way to the new cells to    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1-15-1346-6_32    Fig. 32.1 Various signs of an  ageing face include but not  limited to forehead wrinkles,  droopy eyelids, under-eye  hollowness, deep nasolabial  folds, jowl formation, loose  neck skin and thin lips    come to the surface. This process also eliminates damaged  and contaminated cells that carry pollutants and microorgan-  isms from the environment.   The specialised fibroblasts in the dermal layer produce  two key proteins-collagen and elastin. Collagen constitutes  80% of the dermis and provides strength and firmness to the  skin. While elastin, as the name implies, provides elasticity  to the skin and enables the skin to bounce back to its original  shape after it is stretched, thus preventing wrinkles.   Skin ageing is a dynamic mechanism that transpires due  to two basic factors:    ¢ Intrinsic or Innate factors are insidious deteriorating ele-  ments that are influenced by internal metabolic processes,  genetic programming, cellular metabolism and hormones;   e Extrinsic or Exogenous factors include Ultraviolet rays in  the sunlight, cigarette smoking, environmental pollution,  etc.    Intrinsic ageing is an inevitable natural ageing process  which commences as early as mid-20s. It consists of internal  physiological factors that cause inherent degenerative pro-  cess in the body. Dead corneocytes do not desquamate as  swiftly as expected and the turnover of new epidermal cells  decreases somewhat. In the dermis, the production of colla-  gen and elastin slows down. The cumulative effect which is  seen in case of the inherent ageing includes fine wrinkling,    parched, thin and transparent skin and depleted elastic nature  of the skin.   Extrinsic ageing is because of the aggregated damage  caused by environmental factors such as sun’s UV radiation,  gravity, sleeping posture, pollution, smoking, exposure to  chemicals, etc. These exogenous factors along with the  innate factors cause premature ageing of our facial skin. The  face, which is most commonly exposed part of the human  body to the UV radiations of the sun, undergoes ageing pre-  maturely than any other part. Photoageing with recurrent sun  exposure causes the skin to lose its capability to renovate and  thereby accumulating damage. Recurrent and continual UV  exposure disintegrates collagen and impedes the synthesis of  new collagen. Alongside, there is a breakdown of elastin.  This causes the facial skin to become slack, wrinkled and  leathery much earlier than a sun-protected skin.   Gravity constantly works on different parts of our facial  skin. As the skin elasticity reduces with age, the effects  become evident. It precipitates jowls, nasolabial fold, droop-  ing of eyelids, elongation of ears, etc. (Fig. 32.2).   Sleep lines are wrinkles that are etched on the facial skin  of the people who sleep with the face pressed on the cushion  or sleep on the sides.   Cigarette smoking over a period of time causes many bio-  chemical alterations in our body. It has deleterious effects on  skin and expedites the ageing process. The nicotine causes  vasoconstriction thereby impairing the supply of oxygen and    Fig. 32.2 Influence of ageing on skin. Facial wrinkling, jowls and  droopy eyelids clearly demonstrate the ageing process    important nutrients, such as vitamin A to the skin. Many of  the over 7000 chemicals released from the burning cigarettes  cause increased production of matrix metalloproteinases  (MMP) that causes degradation of collagen and causes  abnormal creation of elastosis materials. These cause prema-  ture facial skin wrinkling.    The subcutaneous fat gives the volume and shape to the face.  As explained by Rohrich and Pessa [1], the subcutaneous fat  is distributed throughout the face in a multidimensional fash-  ion and is highly compartmentalised. A youthful face is char-  acterised by a smooth transition between these subcutaneous  compartments. The superficial musculoaponeurotic system  (SMAS) divides this fat into superficial and deep layers. As  explained anatomically by Rohrich and Pessa [1], the exter-  nal recess is in between the skin and SMAS while the inter-  nal recess lies under the SMAS and is adherent to the  periosteum. The superficial and deep fat recesses are as  explained in Fig. 32.3.   Furnas in 1989 first described the osteocutaneous liga-  ments within the cheek that anchor the dermis to the under-  lying fibro-osseous structures [2]. He outlined the zygomatic  ligaments (McGregor’s patch), the mandibular ligament, the  platysma auricular ligament and the anterior platysma-  cutaneous ligament that anchor the dermis and also support  the midface soft tissue. Two theories explain the character-    istic soft tissue changes that are distinguished during the  mid-face ageing. The gravitational theory advocates that  with the attenuation of the osteocutaneous ligaments, there  is vertical descent of facial soft tissue which contributes to  the deep creases of the ageing face [3]. The diminished  strength of the ligaments is because the age-related elastosis  and also because of the repeated animation of the muscles of  facial expression.   Donofrio explained the volumetric theory in 2000. He  suggested that it’s the corresponding volume loss or gain in  the adjoining areas of the face is what creates the deep  creases of age [4]. This theory was later in 2007 reinforced  by Lambros who stated that the ageing process was due to  the relative deflation of certain fat pads, especially the deep  fat pads [5].    The superficial musculoaponeurotic system is a multidimen-  sional scaffold of organised fibrous tissue that connects the  facial muscles with the dermis [6]. This fibromuscular layer  also segregates the superficial and deep facial fat pads.  Anatomically, the SMAS lies in the midface, inferior to the  zygomatic arch and superior to the muscular belly of the pla-  tysma. It blends with the superficial temporal fascia and  frontalis muscle superiorly, and with the platysma muscle  inferiorly. Since it connects the facial muscles to the dermis,  its purpose is to transmit, distribute and amplify the activity  of all facial muscles [7].   As we age, and with the continuous use of the muscles of  facial expression, the SMAS weakens and the strength  diminishes. So, the ability to hold up the muscles, fat and the  skin gets impaired. Combined with the effect of gravitational  forces, the weakening causes the structures of the face to  slump. The youthful appearance of the face changes as jowls  are formed, the nasolabial fold deepens and the mandibular  line angle becomes ill defined.    The bony skeleton serves as a framework for the soft tissues  of the face including the skin, muscles and subcutaneous fat.  The facial skeleton keeps changing anatomically throughout  life with only degenerative and catabolic changes occurring  after adolescence.   With ageing, the facial skeleton keeps resorbing in a very  predictable manner and that contributes to the appearance of  an aged face. Areas with strong tendency to resorb include  the periorbital area, the midface, the perinasal area and the  mandible (Fig. 32.4).    Superficial fat pads  @©Association of Oral and Maxillofacial Surgeons of India    Fig. 32.3 (a, b) (A) Infraorbital fat, (B) Medial cheek fat, (C) Nasolabial fat, (D) Medial cheek fat, (E) Lateral cheek fat, (F) Superior jow] fat,  (G) Inferior jowl fat, (H) Medial sub-orbicularis fat, (I) Lateral sub-orbicularis fat, (J) Deep medial cheek fat, (K) Buccal fat    Fig.32.4 Various areas of facial skeleton as marked are predominantly  destined to resorb contributing to the appearance of aged face    The orbital aperture enlarges with age in all dimensions.  The superomedial and inferolateral aspects tend to recede  more which imparts the stigmata of periorbital ageing such as  increased prominence of the medial fat pad, elevation of the  medial brow and lengthening of the lid cheek junction [8].    The midface skeleton is formed by the maxilla medially  and the zygoma laterally. With age, the maxilla recedes and  the maxillary angle decreases by about 10° between the age  of 30 and 60 years [9]. The piriform aperture enlarges with  age, as the edges of the nasal bones recede [10]. The anterior  nasal spine also retreats which reduces the skeletal support  and thereby contributing to retraction of the columella, with  a downward rotation of nasal tip and apparent lengthening of  the nose [11]. In regards to the mandible, it is well estab-  lished that the mandibular angle increases, the ramus height  and mandibular body height and length decreases with age  [12]. The above-mentioned skeletal resorption patterns con-  tribute significantly to the appearance of an ageing face.   In the recent years, the demand for facial rejuvenation has  increased exponentially. Individuals from every socioeco-  nomic strata and from all age groups today desire a younger  and rejuvenated look. Evolution of numerous surgical and  non-surgical procedures has led to an increase in patient  demands and expectations. Every aesthetic physician should  understand the facial anatomy and the facial ageing process  well so as to perform the procedures that would best suit the  requirement of the individual to deliver the best of the results.  The various non-surgical modalities of facial rejuvenation  include the use of Botulinum toxin, dermal fillers, thread  lifts, platelet concentrates and radiofrequency waves.  Botulinum toxin and fillers are elaborated in the subsequent  chapter. The following is a detailed description of the role of  thread lifts, platelet concentrates and radiofrequency waves  in achieving facial rejuvenation.    Age-related changes on the face include remodelling in the  facial skeleton and reorganisation of musculature, connec-  tive tissues, fat and skin. The dynamic process of ageing is  unstoppable and it induces an ever-progressing slackness in  the soft tissues that leads to a ptotic brow, jowl formation,  ill-defined mandibular margin and deep nasolabial folds.   Gravity is an important factor that causes drooping of  the upper, mid- and lower-facial soft tissue, which adds to  the effect of an aged appearance. The hollowness of the  midfacial and infra-orbital area is because of the down-  ward shift of the malar fat pad. To manage this ptotic situ-  ation, surgical facelift procedures have been the most  effective treatment as they not only excise the redundant  tissues but also haul the soft tissue in the opposite vector  of ageing process. The other non-invasive procedures can-  not be as effective as the facelift procedure. But because  of the significant downtime, cost and risks involved, face-  lift is not accepted by patients very readily. To have a way  in between the surgical and non-invasive modalities,  thread lift has become a popular procedure to manage  drooping tissue of the face because of ageing.    Thread lifting modality is a minimally invasive cosmetic  procedure that utilises a biocompatible implant placed into  the deeper layers of face to predictably shift and realign tis-  sues in a predetermined direction or vector. When compared  to a surgical facelift procedure, this elevates the drooping tis-  sues with least amount of risks and complications, immedi-  ate results and rapid recovery.   Historically, Ruff in Durham, North Carolina, in 1992 and  Sulamanidze et al. in Moscow, Russia, in 1996 indepen-  dently developed barbed sutures for correcting facial ptosis.  FDA in 2004 approved Ruff’s clear, barbed, unidirectional,  polypropylene sutures for treating ptotic skin of face and  neck [13].    Fig.32.5 Various types of polydioxanone threads are mono threads for  facial rejuvenation and cogs threads for redefining facial contours   e Permanent/Non-resorbable threads—Polypropylene  threads like Aptos threads, Silhouette lift threads,  etc.   e Resorbable threads—Polydioxanone threads like  Alfa aqualift, and Poly-L Lactic acid threads like sil-  houette soft threads, etc.   e Free floating: They are not fixed and cause the pull  because of the thread design.   (D) Depending on the surface texture of the thread:  ¢ Barbed   e Bidirectional barbed threads—these are placed in the  treatment area by a canula and stretch the skin because of  the design, e.g. Aptos threads.   ¢ Cogged threads—these can be unidirectional, bidirec-  tional or multidirectional and they lift the skin towards the  point of entry once tissues get entangled with the cogs.    From a clinical point of view, the barbed sutures simply work  by grasping and mechanically pulling the ptotic skin. These  barbs get entangled in the subcutaneous tissues and as the  thread is pulled backwards, the tissues get squeezed along  the barbs and stay there as the thread outside is cut off.   From a histologic aspect, a basic mechanism of mechani-  cal transduction happens when the polydioxanone threads  are placed in the tissues. A torrent of intracellular signals in  the surrounding cells through which the polydioxanone  threads pass is triggered by the mechanical stresses insti-  gated by the threads thus influencing the metabolic responses  and encouraging cellular growth and survival and modulat-  ing tissue morphology and architecture [14].   There are 2 major types of collagen proteins that are  found in our skin. The type | collagen or the fibrous collagen  makes up about 70% of the total collagen while the type 2  collagen or the reticular collagen makes up to about 5—20%.  Both of them provide structural support to the skin. Today,  most of the aesthetic procedures are aimed at a phenomenon  of biostimulation. The main intention is to improve on the  plasticity, resilience, flexibility, firmness and turgor of the  skin tissues that are normally lost with ageing due to the loss  of proteins like collagen and elastin. This is achieved by pen-  etrating the dermis with substances that would encourage the  production of these proteins [15]. The biostimulation caused  with PDO threads is due to neocollagenesis, i.e. the produc-  tion of type | collagen which is essentially fibrotic in nature.  The PDOs resorb in 6 months and till that time it keeps  inducing collagen. The fibrotic collagen exhibits a retracted  effect improving the skin appearance. Concurrently, the    compaction and stiffening of the collagen fibres also deter-  mine the functional damage [16].    Skin rejuvenation can be done with the use of plain  polydioxanone threads. It also increases the volume in cer-  tain areas where there is minimal volume loss.   The barbed threads are indicated in areas where there is  ptosis of the tissues. The barbs work as cogs and by engaging  the tissues along its path, it mechanically pulls the tissues  upwards thereby reducing the ptosis.   The plain polydioxanone threads can be used for facial  rejuvenation and are mostly utilised for the following indica-  tions (Fig. 32.6):    e Fine lines and wrinkles in any part of the face like the  periorbital area, malar areas, perioral areas, chin, etc.    The barbed threads can be used to lift the ptotic skin and  hence be utilised in the following areas (Fig. 32.8):    Choosing the ideal procedure for rejuvenation depends on  the grade of skin ageing.    Fig. 32.7 (a,b, c) Mono polydioxanone threads can be used to create the lip borders and also to create a fuller looking lip    — for heavy lifting—apply anchored sutures or long 32.2.6 Procedure  suture technique.  (B) Moderate to severe skin ageing The Polydioxanone thread used in facial rejuvenation are  e Rejuvenation—Apply short PDO cogs along with _ basically of 2 types: Mono PDO thread and Cogs PDO thread  plain PDO threads (Fig. 32.10).  e Lifting—Not recommended. (A) The Mono PDO thread—These are 5-0 or 6-0 suture  materials which are essentially monofilament and    Fig. 32.8 Various indications  of barbed PDO threads for  redefining facial contours and  lift the ptotic tissues    Fig. 32.10 Cogs thread for lifting nasolabial folds. Note the lifted up  right nasolabial fold only as the thread has been applied only on that  side. Left side is still untreated    non-barbed. It can also be braided to a spring to provide  more tensile strength [17]. The thin suture material  forms a V-shape when inserted to a needle of 26-30 g,  with one half of the thread inside the calibre of the nee-  dle and the other half on the outside. Once the needle  with the suture material is inserted into the dermal layer,  the thread gets buried into the tissues and at the removal  of the needle, the thread stays back intact.   These types of threads are placed in the dermal layer  where they cause collagen formation.   EMLA cream must be applied 45 min prior to the  procedure. The full face was cleansed with povidone  iodine solution. Once ready, the mono PDO threads  are placed in the dermal layer making up meshes in  the areas of indication. One must keep observing for  any threads that stay outside the skin. It must be  removed immediately by grasping it with a needle  holder so that it doesn’t cause any infection or  granuloma.   (B) The Cogs PDO thread—Cog PDO thread has small  barbs or spikes all along its length, which get engaged to  the tissues when inserted and lifts it once pulled back.   Depending on the direction of the spikes, cog PDO thread is  classified as unidirectional, bidirectional or  multidirectional.   The cog thread is actually 3-0 suture which has barbs and  this thread is mounted on an 18 g canula or needle. The  canula is considered safer as it does not damage the blood  vessels and nerves.   The barbed threads must be placed in the subcutaneous layer  so as to prevent any palpability of the implant material.   Local anaesthesia should be given with 2% lidocaine with  epinephrine. The full face is cleansed with povidone  iodine solution. The path of insertion of the canula is  marked on the skin with a sterile marking pen. The vec-  tors are checked by manually stretching the skin upwards.  Point of insertion is marked on a line 1.5 cm in the preau-  ricular area. A small opening is made with an 18 g needle  for the insertion of the canula. The barbed thread mounted  on the canula is then passed along the vector in the sub-  cutaneous plane all the way till the nasolabial fold or the  marionette line. Once in place, the end part of the thread  gets hooked in the subcutaneous plane, and the canula is  pulled back and taken off the skin. The thread stays  entangled in the subcutaneous plane. Once all threads are  positioned in the skin, the distal part of the suture is held  in one hand and the skin is pushed in the opposite direc-  tion to fully engage the threads and lift the tissues. The  end part of the suture is then cut very close to the skin  with help of sharp scissors so that the ends go into the  tissues to prevent any future granuloma formation  (Figs. 32.1 1la—d).    Post-operatively, ice packs are applied to minimise edema  and bruising. Oral antibiotics are prescribed for 5 days after  the procedure.   Anti-inflammatory tablets should be avoided as the more the  inflammation at the site, the better would be the results. Patients  generally do not require anti-inflammatory drugs post-surgery.  Within the first 3 weeks after the procedure, the patients are  advised against any strenuous movements of the muscles of  midface such as yawning, wide smiling and laughing.    The various complications that could occur with the PDO  barbed threads include:    1. Bruising—Bruising is quite common while placing the  PDO threads. Post-procedure application of ice prevents  further bruise.   2. Pain and Swelling—Thread lift surgery causes very  mild to moderate post-operative pain and swelling.  Patients are generally asked to apply ice externally to  reduce inflammation and pain. If a patient complains of  severe pain, anti-inflammatory may be advised. In case  of serious swelling, the patient must be evaluated for  hematoma and infections.   3. Infection—Proper aseptic protocol needs to be followed  to prevent any type of skin infection. However, it is bet-  ter to prescribe oral antibiotics for 5 days for the thread  lift surgery.   4. Palpability of the thread—If the threads are placed too  superficial, they become palpable from outside the skin.  The barbs or cogs should always be placed in the subcu-  taneous layer.   5. Hematoma—Since the placement of threads is a blind  procedure, the chances of damage to a blood vessel is  always there. The patient should always be informed  prior to the procedure regarding hematoma. Pressure  application and cold compressions should be immedi-  ately given. After a period of time, the skin over the  hematoma may turn bluish then brown and yellow as the  blood is dissolved and absorbed. It may take 1-4 weeks  for the hematoma to subside.   6. Nerve damage (Fig. 32.12)—There is always a chance  of trauma to the branches of facial nerve since the place-  ment of the threads is in close vicinity to the nerve, espe-  cially the marginal mandibular and frontal branches.  Thus, the muscles of facial expression can be impaired.  Fortunately, the nerve damage resolves soon and motor  functions are restored.   7. Asymmetry: Pre-existing asymmetries on the face  should be explained to the patient prior to treatment. It’s    always a good practice to let the patient seat vertically  straight while inserting the barb threads and making the  patient participate while retracting the tissues by visual-  ising with a mirror to avoid any potential problems of  asymmetry later on.    the advancing thread is too superficial. A depression  or an irregular contour would occur at a portion where  the barb is located close to the skin. Most cases nor-  mally resolve spontaneously. But remarkable dimples  need to be managed by manual reduction at that time  itself.   Rippling and puckering: The skin would ripple over the  thread and cause visible folding if tightened too much  while retracting the tissues. This typically resolves itself  in a few days if the thread has been placed in the correct  tissue plane.    Granuloma: Higher incidences of granuloma formation  are essentially seen if the threads placed in a more super-  ficial plane and they are not cut very close to the skin.    truding thread, the end should not be cut as with barbs  and cogs, but grasped firmly and removed. It’s safer to  remove a monofilament thread than leaving it there, thus  risking the formation of granuloma. Barbed and cogged  threads are very difficult to retrieve and hence excessive  care should be taken to place them in the right plane.  Thread breakage: This can happen during the tightening  of the barbs and cogs just before cutting at the skin level.  Hence, careful manipulation should be done to avoid  breakage during insertion and tightening.    the thread to superficial layers can cause thread exposure. It  can be prevented by placing the threads in proper plane.    Fig. 32.11 (a, b) Placement of cannula with cogs threads along the vectors for nasolabial folds and after removal of cannula the cogs threads in  place. (c, d) Pulling the cogs threads to lift the ptotic nasolabial fold tissues and final twisting and snipping the threads just below the skin level    The PDO thread lift is a non-invasive procedure that actually  gives a “lifted effect” of the ptotic skin. It has been widely  accepted as a standard procedure for patients who do not  want to opt for a more aggressive surgical facelift. Patient  selection is of prime importance. Only patients with mild to  slightly moderate levels of ptosis should be selected for  polydioxanone cogs thread lift. The patient should be given a  realistic expectation of the lift of no more than | cm. Patients  who are too chubby or who are too skinny should not be  considered for thread lift. Overall, every aesthetic practitio-  ner should have knowledge of thread lift as it is a simple and  versatile anti-ageing procedure.    Today, Platelet-rich plasma (PRP) has been incorporated in  many medical specialities including orthopaedics, general  surgery, plastic surgery, dental surgery and dermatology  because of its healing capabilities. Its usage in aesthetics and  trichology has touched newer horizons as we have come to  know about the healing cytokines present in the platelets  which can be used for antiageing therapies and therapies for  regenerative aesthetics.    Fig. 32.12 (a, b) Damage to frontal branch of the facial nerve during placement of cogs threads    Platelets, also called thrombocytes, are enucleated fragments  of cytoplasm that are derived from the megakaryocytes of the  bone marrow, which are released into the circulation. They  have a fundamental role in haemostasis and wound healing.   The platelets contain various secretory granules, namely  the alpha granules, dense granules and lysosomes. The  alpha granules are the most abundant ones and contain the  coagulation factors, growth factors, also called cytokines,  adhesion molecules, and a variety of other angiogenic fac-  tors which efficiently encourage the proliferation and acti-  vation of cells required for wound healing including  fibroblasts, mesenchymal stem cells (MSCs) and facilitates  angiogenesis [18].   The growth factors along with their function are listed  below [19]:    1. PDGF (platelet-derived growth factor)—PDGF plays a  role in embryonic development, cell proliferation, cell  migration and angiogenesis.   2. TGF-B1 & $2 (transforming growth factor)—TGF is  involved in regulating and mediating processes at the cel-  lular level, including cell proliferation, differentiation,    motility, adhesion and apoptosis as well as causes wound  healing and angiogenesis.   3. VEGF (vascular endothelial growth factor)—Chemotactic  and mitogenic for endothelial cells, mediates  angiogenesis.   4. EGF (epidermal growth factor)—Mediates angiogenesis,  causes proliferation of fibroblasts, endothelial cells and  keratinocytes.    These growth factors or the “cytokines” are proteins,  each of about 25,000 Daltons molecular weight. In response  to the thrombocyte aggregation, as occurs in injury or sur-  gery, the cell membrane activates the alpha granules which  in turn unleash these growth factors via active extrusion  through the cell membrane. The active secretion begins  within 10 min during which 70% of stored growth factors  are released and more than 95% of the presynthesised  growth factors are secreted within | hour. Platelets then syn-  thesise additional amount of growth factors for about 8 days  till they die [20].    Platelet concentrate means plentiful amounts of platelets  that are concentrated into a small volume of plasma. There  are various types of platelet concentrates which can be for-  mulated, all differing in the way they are made [21]. A gen-  eral classification takes 2 key parameters into consideration:  the presence of a cell content (mostly leukocytes) and the  fibrin architecture.    1. P-PRP  Pure Platelet-rich plasma is a preparation without  Leukocytes. It has low-density fibrin network after activa-  tion. It is used as liquid solutions or an activated gel form  and can be injected. P-PRP is commonly used in sports  medicine & aesthetic medicine.  2. L-PRP  Leukocyte and PRP is a preparation with leukocytes in  it. Even this has low-density fibrin network after activa-  tion. It is used as liquid solutions or an activated gel form  and can be injected. L-PRP is used in aesthetic medicine,  sports medicine, orthopaedics, trichology, etc.  3. P-PRF  Pure Platelet-rich fibrin is a preparation without leuko-  cytes. It has a high-density fibrin network and exists as a  strongly activated gel form. It cannot be injected, but can  be handled like a real solid material. It has been very com-  monly used in dentistry & maxillofacial surgery today.  4. L-PRF  Leukocyte and PRF is a preparation with leukocytes. It has a  high density of fibrin network and exists as a strongly  activated gel form. It cannot be injected and can be han-  dled as a real solid material. It is today used in implant  dentistry, periodontal surgeries, oral surgeries, treatment  of skin wound ulcers, etc.    PRP can be described as a biologic product derived from  autologous blood with the plasma fraction containing plate-  lets at a concentration of more than 3-5 times above  baseline.   The scientific evidence suggests that wound healing  enhancement is seen using concentrates of 1,000,000 plate-  lets/y11. Any concentration lower than this cannot be depended  on to enhance wound healing, and concentrations far more  than this has not been scientifically proved to help and  enhance healing [22].   So, PRP by virtue of its increased concentration of plate-  lets and thereby an inflated amount of growth factors or cyto-    kines have been theorised to encourage tissue repair and  regeneration by neocollagenesis, neoangiogenesis and much  more. It has been embraced as a frontline treatment modality  for the management of facial ageing, androgenetic alopecia,  acne scarring, etc.    PRP is derived from autologous blood by using a centrifuge  and can be performed under local anaesthesia under aseptic  conditions. An anticoagulant, like citrate dextrose solution  formula A (ACD-A) or sodium citrate 3.8%, is used to inhibit  platelet aggregation.   Whole blood is collected by venipuncture from antecubital  vein in 15 ml polystyrene tubes under sterile conditions con-  taining 3.8% sodium citrate as an anticoagulant. In each  tube, | ml of sodium citrate is mixed with 12 ml of whole  blood. Eight such tubes are taken to make up a volume of  104 ml. The tubes are slowly turned upside down twice to  homogeneously mix the whole blood with the anticoagulant.  All the 8 tubes are placed in the centrifuge (Remi 8c) and are  centrifuged at 1500 rpm for 10 min. This is called the ‘soft  spin’ which separates the whole blood into 3 layers. The  erythrocytes settle at the bottom of the tube because of the  highest specific gravity or density of about 1.090. Just above  the erythrocytes, a hazy layer is seen which contains the leu-  cocytes with a specific gravity of 1.060 and platelets with a  specific gravity around 1.040. At the top, we find the clear  plasma with the lowest concentration of platelets with a spe-  cific gravity of around 1.020.   The buffy coat is separated along with some amount of  plasma and placed in a separate tube. At this time, if the buffy  coat is separated along with the slightest superficial erythro-  cyte layer, it is referred to as L-PRP (leukocyte-PRP) and if it    Fig. 32.13 (a, b, c) Primary separation of erythrocytes during the preparation of platelet-rich plasma using plain tubes containing sodium citrate    is taken above the layer of erythrocytes, it is referred to as  P-PRP (pure-PRP) depending on the kind of PRP preparation,  i.e. with or without leukocytes. About 10 ml of these are taken  in 2 tubes and placed in the centrifuge for a second spin called  the ‘hard spin’ at 2500 rpm for 15 min. At the end of the spin,  a platelet plug is found at the bottom of the tube. The top 3  quarter of the platelet poor plasma was discarded and the low-  est quarter with the platelet plug was mixed and used as the  PRP. This gives us a viable platelet count of 5 times the base-  line. This was activated by mixing with calcium gluconate at a  ratio of 9:1 in an insulin syringe and injected immediately.   Numerous commercial devices of varying standards are now  available for the preparation of PRP. Although time saving,  these adapted kits can be quite expensive as compared to the  manual process.    In general, a PRP tube typically contains sodium citrate as  an anticoagulant along with a separating gel. This gel has a  density of about 1.070, which is in between the erythrocytes  and platelets.   20 ml of Whole blood is collected by venipuncture and  added into two of these PRP tubes. The blood is homogeneously  mixed with the anticoagulant by gently turning the tube upside  down twice. The tubes are then placed in the centrifuge and  spun at 3700 rpm for 9 min. The erythrocytes because of the  higher density than the separating gel settle down below the gel,  while the plasma along with leucocytes and platelets segregate  above the gel. The superficial platelet poor plasma is discarded  leaving behind 2-3 ml of plasma above the gel. The tubes can be  turned upside down to mix the platelets as they get entangled in  the gel. This would give a uniform concentration of platelets  throughout. It is now mixed with calcium gluconate as an acti-  vator and injected immediately.    32.3.5 PRP Injections for Facial Rejuvenation,  Biostimulatory Lift and Acne Scar    Studies have shown that PRP by inducing neocollagenesis  through activation of fibroblasts and by removing photodam-  aged extracellular matrix (ECM) components amplifies der-  mal elasticity via following molecular mechanisms [23, 24]:    e Encouraging proliferation of human dermal fibroblasts to  induce new collagen.   e Increased expression of MMP-1 (matrix metalloprotein-  ase-1) and MMP-3, resulting in the removal of photodam-  aged ECM.   e Enhanced creation of procollagen type I peptide and  expression of collagen type I, alpha-I, resulting in the syn-  thesis of fresh collagen.   e Increases expression of G1 cell cycle regulators resulting  in accelerated wound healing.    PRP can be injected using an insulin syringe that has 31 g  needle. Local anaesthetic in the form of nerve blocks should    be given prior to the session. The facial skin should be  cleansed with povidone iodine solution. Multiple intrader-  mal injections of PRP after activating it are given all over the  face including the infraorbital area. Three sessions each at a  gap of 1 month of PRP therapy along with micro-needling  (collagen induction therapy) with derma pen with a needle  depth of 0.7-1 mm has been shown to give very good results  for rejuvenating the aged skin and acne scars. Histologically,  the treated skin showed improved length of dermo-epidermal  junction, increased quantity of collagen and fibroblasts.   Post-operatively, patients are advised to apply ice on the  face. Sun exposure should be avoided. Patient should be  advised not to take anti-inflammatory tablets as the more the  inflammation, the better the results are going to be. Most of  the times, patients experience very mild post-operative  discomfort.   PRP therapy can also be combined with CO2 fractional  resurfacing to achieve excellent results in treating acne scars.   PRP has also shown excellent results in infraorbital reju-  venation where the skin is very thin and shows initial signs  of ageing [25].    2.15 (a, b, c) Platelet plug formed after the second spin during the preparation of L-PRP    The use of cytokines derived from platelet-rich plasma (PRP)  is an effective modality to promote tissue regeneration and  hence can be used in regenerative medicine including facial  aesthetics and trichology.   PRP therapy is an inexpensive procedure as it does not  require complex and voluminous equipment or extensive  training for its execution. Furthermore, since the product is  primarily autologous in origin, the patient’s apprehension  regarding the immunogenic reactions or disease transmis-  sion is abolished. Over three decades of its application to  various fields and the multitude of studies with enormous  positive results, PRP therapy today has become a gold stan-  dard for facial rejuvenation and hair loss therapy. The release  of bioactive cytokines that help in neocollagenesis which  takes care of the ageing process of wrinkle formation has  made it a versatile tool for many anti-ageing therapies on the  face.    Fig. 32.16 (a, b, c) Platelet-rich plasma needs to be activated for release of cytokines from the alpha granules    Facial wrinkles, reduced elasticity of the facial skin and sag-  ging parts of the face are the most common concerns today an  aesthetic surgeon encounters from the patients. In the present  social scenario, facial skin laxity is considered highly dis-  graceful and has a great impact on a person’s psychology and  quality of life [27]. The natural process of ageing which is  inevitable and the other external factors like sun’s UV radia-  tions, stress and worry, smoking, unhealthy diet, etc. are the  major factors which cause the wrinkles and sagginess. We are  aware that the loss of the important proteins viz collagen and  elastin, which gives the strength, resilience and elasticity to  the skin is the reason behind the loose skin and wrinkles.   Various treatment modalities have been utilised to man-  age these concerns of the face. Surgical excision of the  redundant skin via facelift surgery definitely gives the best  results. But with the increasing concerns over the complica-  tions and the downtime, the focus of therapeutic modalities  is shifting towards non-surgical aspects.    Non-surgical treatment modalities like microdermabra-  sion, chemical peels, fractional lasers, etc. have been advo-  cated in the past. In recent times, newer modalities like the  HIFU and RF have come into limelight due to their non-  invasiveness and low or no downtime for the treatment of  sagging skin.    Ultrasound was introduced for its diagnostic ability. The  capability of the focussed ultrasound energy to cause tissue  regression and ablation has been well utilised today as a non-  invasive modality to treat solid tumours and also being used  to treat both primary and metastatic tumours as these can  precisely locate the mass for ablation [28].   More recently this intense focussed ultrasound has also  been utilised in many painful conditions including neuro-  pathic pain and musculoskeletal degeneration [29].    & Sodium citrate  @©Association of Oral and Maxillofacial Surgeons of India    Fig. 32.17 (a, b, ce) Preparation of Platelet-rich plasma with the help of PRP tubes containing anticoagulants and the separating gel    HIFU or high intensity focussed ultrasound was intro-  duced into the field of facial aesthetics very recently to man-  age the facial wrinkles and periorbital rejuvenation.   FDA in 2009 approved the use of HIFU in brow lifting as  the first dermatologic and aesthetic indication following the  report by White et al. [30] in 2008. It was later in 2014  cleared as an indication to improve lines and wrinkles of the  upper chest and neckline (décolletage). Currently, its use for  facial rejuvenation, skin lifting and tightening and body con-  touring is considered ‘off-label’.    High intensity focussed ultrasound or HIFU embodies a  piezoelectric transducer which produces focussed ultrasound  beams. This transducer releases ultrasound waves over a  length of around 2.5 cm which are focussed at 1.5, 3 or  4.5 mm depth. The 1.5 mm focusses the superficial or papil-  lary dermis, while the 3 mm focusses the deep or reticular  dermis and the 4.5 mm focusses the SMAS layer. Like a  magnifying glass, the transducer focusses the ultrasound to    the desired depth and at the focal spot, there is a swift rise in  temperature to 60—-80°C within a very short period (typically  1-20 s). This causes an immediate contraction of native col-  lagen which is subsequently followed by cell injury and tis-  sue shattering due to both coagulation necrosis and protein  denaturation. These events occur at the deeper focussed  zones, while the superficial tissues are left safe and unaf-  fected [31] (Fig. 32.18).   The focussed ultrasound energy is absorbed by the tis-  sues and this causes the molecules to vibrate rapidly. The  friction due to molecular oscillations results in heat gen-  eration and a rapid rise of temperature at the focal zone.  This thermomechanical process causes tissue injury at the  site of focus. Supplemental to this, the ultrasound waves  that propagate through the tissues cause continuous com-  pressions and rarefactions that result in powerful shear  forces. This microscopic but mighty shearing motion  results in frictional heating [32]. Once tissue destruction  is done, the inflammatory phase (in first 48 h) sets in  wherein the damaged cells are removed and the WBCs,  growth factors and enzymes create swelling, heat, pain  and redness.    Fig. 32.18 Mechanism of  high-intensity focussed  ultrasound. Thermal  coagulation zones are created    due to the extreme heat  produced by the ultrasound  focussed to a particular depth    In the next proliferative phase (up to 6 weeks), there is  tissue contracture due to the myofibroblasts which are built.  New tissues made up of collagen and extracellular matrix are  formed.   The last maturation phase (from 3 weeks to 6 months)  shows collagen is remodelling from type III to type I. The  collagen which was laid down during the proliferative  phase is now aligned along the tension lines and also there  is cross-linking of the collagen. A histological evaluation  post HIFU treatment exhibited significantly regenerated  and proliferated quantity of dermal collagen and elastic  fibres [33]. This causes skin tightening over a period of  time. The results keep improving and the best final results  are seen by 6 months.    The HIFU machine basically consists of 2 parts: the body  and the transducer (Fig. 32.19).   The screen in the body keeps monitoring the number of  shots, depth of shots, length of release of ultrasound waves  and the energy of the ultrasound in real time. The transducer  releases the focussed ultrasound waves. The following are  the 3 transducers usually used on the face:    transmitted to a depth of 4.5 mm to the SMAS layer,  forming “thermal coagulation” spots. It is normally tar-  geted to thicker skin, such as cheeks, etc. and is the most  important aspect of midface tightening.    focussed to the deep dermis layer at 3.0 mm depth and is  responsible for activating the skin’s collagen. It effec-  tively reduces the appearance of wrinkles and also ame-  liorates large pores.    is focussed to the superficial dermis. It is used in thinner  tissue in the periorbital area.    . Pustular acne in the treatment region.  . Active implants (e.g. pacemakers or defibrillators) in    1. Patient consent and explanation of the procedure, adverse  effects and alternatives.   Toplap, etc., and occluding it with plastic sheet for 45 min.   6. Application of ultrasound gel on the skin and face and  application of transducer tip at an angle perpendicular to  the skin.   7. Start with 4.5 mm transducer, followed by 3 mm and then    1.5 mm with a number of shots and area as mentioned in  the figures.   8. Removal of ultrasound gel and explaining post-operative  instructions before discharging the patient.   9. Follow up on the next day to assess any complications  and at 3 and 6 months to assess the results.    Severe adverse effects of HIFU are very rare and hence con-  sidered a very safe procedure to perform on an outpatient  basis. The adverse effects that have been described may be:    e Pain—Transient discomfort may be experiences during  the procedure which resolves within 2 h to 2 days.  Tenderness is also possible and typically resolves in max-  imum 2 weeks.   e Erythema—May exhibit immediately after the treatment  which resolves in few hours (Fig. 32.21).   e Motor Nerve paresis—Symptoms of motor nerve paresis  can be seen in the first 12 h of the treatment. It normally hap-  pens with the marginal mandibular and temporal branches of  facial nerve which are pretty superficial. The HIFU could  cause inflammation of these nerves and this may lead to dis-  ruption of motor function. The frontalis muscle and the mus-  cles of perioral area are affected. The symptoms usually  resolve in 2-6 weeks. Anti-inflammatory medications can be  prescribed if symptoms of nerve paresis arise.    e Skin burns: This happens when inadequate ultrasound gel  is not applied between the transducer and the skin. There  is thus inadequate acoustic coupling and defocussing of  the beam due to air entrapment and deposition of energy  at the skin surface leading to skin burn (Fig. 32.21).   e Scarring: Rarely happens if correct treatment protocol  and technique is not followed.    HIFU can be considered as a very effective, non-invasive and  safe procedure for tightening the facial skin. The advantages  over a surgical facelift are hard to deny. There are no inci-  sions, no scarring and no downtime. Of course, it is much  less expensive than a surgical facelift. If patients are chosen  carefully, like patients with mild to moderate skin laxity,  facial wrinkles, lower eyelid laxity, etc., HIFU can be an  excellent option for facial skin tightening.    Fig. 32.22 Mechanism of action of non-ablative radiofrequency. Collagen remodelling takes place because of the heat generated due to the tissue    Non-ablative radiofrequency or RF is another non-surgical  and non-invasive modality of skin tightening. The selective  and controlled rise in tissue temperature is because of a high-  frequency alternating current (0.3-10 MHz). The amount of  energy applied and the tissue resistance determine the  amount of temperature and the depth of heating [34].   Since electrical current produces the RF energy, the tissue  damage like a laser is minimised and neither is the epidermal  melanin compromised to cause hyperpigmentation.   RF therapy was first FDA approved as a non-invasive  treatment modality in periorbital rhytids in 2002.  Subsequently in 2004 it was cleared for full face. Since then,  it has become a very popular non-invasive treatment modal-  ity for the facial skin tightening.    High frequency (0.3—10 MHz) alternating current is utilised  ina RF therapy. Intrinsic tissue resistance (impedance) to the  passage of electrons converts the electric current to thermal  energy causing heat generation. Ohm’s Law relationships  state that:    Power(P) =I x Rand Energy (£) =PxT  Hence, Energy (£) = FP x R x T (where / = current, R = tis-    sue impedance and T = time of application). The level of  energy of the alternating current and tissue resistance deter-    mines the amount of rise in temperature and the depth of  heating. High tissue resistance as demonstrated by subcuta-  neous fat generate more heat [35]. The thermal damage thus  caused stimulates the alterations in collagen configuration  and produces neocollagenesis in deep layers of skin and sub-  cutaneous tissue (Fig. 32.22).   Significant results can be observed 2 months post-  application of radiofrequency energy. Histological pictures  after each session demonstrated expansion of the papillary  dermis due to oedema and vascular congestion, followed by  accumulation of intercellular substance. Post 2 months  treatment histological pictures showed escalated amount of  collagen, elastic fibres and mucopolysaccharides [36].    There are 2 major components of the RF machine: the RF  generator and the handheld tips (Fig. 32.23). The membrane  electrode functions by dispersing energy uniformly across the  skin surface by a mechanism termed as capacitive coupling  that creates a zone of raised temperature at depths of 3-6 mm  [37]. The energy transmitted to the skin is by utilising the  capacitive method (bipolar, tripolar or multipolar electrode).  Montesi et al. (2007) described the main difference between  the inductive and the capacitive method. It depends on the  configuration of the electrodes that are applied to the skin that  influences the energy transmission in the tissues.   The inductive method (monopolar electrode) uses an  active and a passive electrode, in which the passive electrode    acts as a grounding electrode. The active electrode transmits  power to the tissue via a single point of contact. This enhances  the penetration of the generated current.   In the capacitive method (bipolar, tripolar or multipolar  electrode), energy alternates between 2 electrodes situated  at a short distance from one another. In the tripolar and  multipolar devices, bipolar energy switches between dif-    ferent poles at any given point of time. The energy is con-  centrated at the site of treatment and the achieved depth is  half of the distance between the two electrodes [38].   Parameters utilised by the device includes frequency rang-  ing from | to 6 MHz and the power ranging from 40 to  240 W. All the parameters can be modified during the treat-  ment. Throughout the procedure, the temperature of epider-  mis is maintained at 40 °C, whereas that of dermis rises to  about 50-75 °C. This heating up of the dermis causes new  collagen and elastin production.    The biggest advantage of RF is unlike lasers, the energy does  not disturb the epidermal melanocytes and thus can be used  for all skin types, i.e. type 1-6. The procedure can be per-  formed frequently as per requirement without any adverse  effect and different depths of tissue can be treated, allowing  for ultimate collagen contraction and production of new  collagen.    Application of RF is done systematically and the various  steps involved are mentioned below.    1. Patient consent for the treatment is mandatory after a  detailed explanation of the procedure, side effects, bene-  fits and alternatives.   4. Application of prilocaine and lignocaine skin anaesthetic  cream like toplap, prilido, etc.   5. Ultrasound gel is applied generously to the facial skin to  establish uniform thermal and electrical contact between  the treatment tip and the skin and to enhance proper  energy conduction.   6. For each session, a total of 5-8 passes per treatment  region can be given.   7. Removal of ultrasound gel and explaining post-operative  instructions before discharging the patient. Post-operative  instruction includes prevention of sun exposure by using  sunscreen to promote healing.   8. Follow up on the next day to assess any complications  and at 1, 3, 5 weeks to repeat the procedure and at 3 and 6  months to assess the results. The possible side effects of  RF application are found in Box 32.1.    Non-ablative radiofrequency is an effective and non-invasive  modality for tightening and rejuvenating wrinkled, photo-  aged facial skin and contour facial skin laxity. It works on the  principle of stimulation repair process by producing new col-  lagen and elastin and by reversing the clinical and the histo-  pathological signs of ageing. The procedure has an added  advantage of being relatively risk-free with little or no  downtime.    A 48-year female approached us with complaints of sag-  ging skin. She wasn’t happy with her deepening nasolabial  folds, loose skin in her neck and the fine wrinkling on her  face.   Treatment options included surgical facelift, thread lift  therapy and non-invasive therapies like HIFU and RF. The  patient consented to undergo non-invasive treatment which  included a session of High intensity focussed ultrasound  (HIFU).   After cleansing the face, proper markings were made. The  treatment was performed with sequential transducers of 4.5,  3 and 1.5 mm with number of shot as recommended, area  wise. The patient was evaluated post-operatively and  patient’s satisfaction was recorded. Post-operative instruc-  tions were given before discharging. Patient was recalled for  revaluation after 1 month.    A 52-year male approached us with complaints of loose skin  on the face. His main concern was the deepening nasolabial  folds and the fine wrinkling on the face. The treatment  options included surgical facelift and thread lift therapy. The  patient consented to get a thread lift procedure done. It was  decided to use 3 COG threads along with 20 mono PDO  threads on either side.   After cleansing the face with povidone iodine, vectors  were marked to lift the nasolabial folds. Lignocaine with  adrenalin was used as local anaesthetic agent. The thread lift  procedure with COGS thread was performed with placement  of the COGS in the subcutaneous layer for the proper lift and    Fig. 32.25 (a—b) Case Scenario 1. (a) Pre-op photograph. (b, c) Marking on face and neck, right side. (d) Post-op photograph    Fig. 32.26 Case Scenario 2. (a) Pre-op photograph. (b) Marking of vectors. (c) 3 cogs in place at subcutaneous layer. (d) The traction on threads  lifts the nasolabials. (e) Placement of mono PDOS. (f, g) Post-op photograph (also see Fig. 32.10)    the mono PDO at the dermal layer for rejuvenation and fine  lines.    satisfaction was recorded. Post-operative instructions were  given before discharging. Patient was recalled for revalua-  tion after 3 days and after 1 month.    Rohrich RJ, Pessa JE. The fat compartments of the face: anatomy  and clinical implications for cosmetic surgery. Plast Reconstr Surg.  2007;119(7):2219-27.    . Furnas DW. The retaining ligaments of the cheek. Plast Reconstr    . Wulc AE, Sharma P, Czyz CN. The anatomic basis of midfacial    aging. In: Midfacial rejuvenation. New York, NY: Springer; 2012.  p. 15-28.    . Gosain AK, Yousif NJ, Madiedo G, Larson DL, Matloub HS,    Sanger JR. Surgical anatomy of the SMAS: a reinvestigation. Plast  Reconstr Surg. 1993;92(7):1254-63.    . Mendelson B, Wong CH. 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Open Access _ This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.  org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropri-  ate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.   The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in  a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.    The field of cosmetology has steadily progressed over the  past decade, and cosmetic procedures are moving towards a  new era [1]. People are becoming more aware of the way  they look, especially the face and are turning to medical and  dental professionals to improve their appearance. Attractive  facial aesthetics at any age has social and psychological ben-  efits. Facial skin constitutes a major part in contributing to  facial aesthetics. The skin is a reflection of several body  characteristics, of which gender is a prominent one [1]. Age,  genetic, hormonal and exogenous factors can affect both skin  structure and function and are responsible for differences  between different men and women. This chapter gives the  basics and advances in the field of facial cosmetic and func-  tional correction using Neurotoxins (Botulinum toxin) and  Dermal Fillers.    In humans, skin including the epidermis and dermis is 1.428  times thicker in men than in women across 5-90 years of age  [1]. However, women tend to have thicker subcutaneous fat.  It has been found that, in men, it gradually becomes thinner  with advancing age (12—93 years), whereas in women, the    Electronic Supplementary Material The online version of this chap-  ter (https://doi.org/10.1007/978-98 1-15-1346-6_33) contains supple-  mentary material, which is available to authorized users.    S. Matsa (2!)  Praseedha Clinic for Maxillofacial Cosmetic Surgery,  Chennai, Tamil Nadu, India    © The Association of Oral and Maxillofacial Surgeons of India 2021    skin thickness remains constant till the fifth decade, after  which it tends to decrease [2].   Gender plays an important role in facial wrinkling. In  men, the incidence of forehead wrinkles is higher than in  women. However, the incidence of upper eyelid wrinkles  does not appear to be influenced by gender. Wrinkles in other  parts of the face are found to be greater in men than in  women, except above 65 years of age, when the incidence  appears to equalise [3]. One study evaluated the skin mor-  phology, elasticity and areas of sagging using photographs  and a cutometer. The authors found that these were similar in  both genders in the cheek region, but in the lower eyelids,  sagging was more severe in males after middle age [4, 5].    A good understanding of the action of the various facial mus-  cles is important for precise application of botulinum toxin.  The muscles and their actions are tabulated (Table 33.1).    Botulinum Toxin type A was first used on the face by  Carruthers and Carruthers in the late 1980s [6]. Following  studies in the 1990s about its cosmetic use, botulinum toxin  was approved by the USA Food and Drug Administration  (FDA). This led to a revolution in treating ageing skin in  recent years [1].    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1-15-1346-6_33   Procerus—Pulls the glabellar skin in an inferior direction and causes  transverse wrinkles   Depressor Anguli Oris—Draws the corner of the mouth inferiorly  Depressor Labii Inferioris—Pulls the lower lip downwards  Modiolus—It’s a union of muscles, situated lateral to the external  commissure of the mouth, allowing symmetrical perioral expression.    Clostridium botulinum produces an exotoxin. It is an anaero-  bic gram positive bacillus (Fig. 33.2) which forms spores. It    has eight types of strains which are labelled alphabetically:  A, B, C, D, E, F, G, and H [7].   Two types of strains, A and B, are available currently.  These result from the modification of the protein structure  that has been used for a variety of medical and cosmetic pur-  pose. Botulinum Neurotoxin causes denervation of the motor  neuron temporarily, in the treated muscle and selectively  inactivates the nerve terminals by blocking the release of  acetylcholine and the target protein SNAP25, [8] leading to  a temporary and reversible blockade of cholinergic transmis-  sion. In the neuromuscular junction, the blockade of the  release of acetylcholine promotes muscle relaxation to mus-  cular palsy [9] (Fig. 33.3a, b, c).   Botulinum Toxin Type-A is available as lyophilised pow-  der that must be stored frozen —4 °C or lower. Reconstitution  of the powder may be done using 0.9% Normal Saline  solution, which is isotonic. Once reconstituted, the solu-  tion must be used within 4-8 h, after which the potency of  the drug may be lost, and contamination of the vials may  occur.   ¢ In mice, the Median Lethal Dose is 1 U. The MLD in  humans is estimated at 3000 U.   ¢ For reconstituting 100 U, 2.5 ml of 0.9% Normal Saline  may be used, which gives a concentration of 40 U/ml.  Many commercial brands are available for Botulinum    Botulinum toxin injections may be used in the clinical sce-  narios highlighted in Box 33.1.    Box 33.1 Indications of Botulinum Toxin  e Wrinkling of the face  ¢ Facial rejuvenation of ageing face  ¢ Gingival smile  e Masseteric hypertrophy  e Facial asymmetry  e Platysmal wrinkling and bands  e Hyperhidrotic conditions (excessive sweating)  ¢ Blepharospasm  e Spasmodic torticollis  e Dystonia  — cranial, lower facial, cervical, oromandibular.    33.2.3.1 Contraindications [10]  The use of Botulinum toxin injections is contraindicated in  the following clinical situations:   e Individuals with an infection in the proposed area of the  injection.   ¢ Individuals under medications that may influence neuro-  muscular transmission. These include Calcium channel  blockers, Penicillamine, Quinine, Aminoglycosides,  Pancuronium, Tubocurarine and Succinylcholine.   ¢ Individuals under medications that interfere with coagu-  lation like Acetylsalicylic Acid, Anticoagulants and  Vitamin E.   In the present era, patients have increased awareness and  knowledge about their health and skin conditions. They may  be very ambitious and optimistic about the procedure and are  likely to expect a high level of satisfaction with their personal  appearance after the treatment. The goal of treatment is to  achieve a better looking and natural appearance. The patients’  psychological aspects and expectations should be understood  and evaluated prior to the start of any cosmetic treatment.    The following techniques are used for injecting botulinum  toxin into various areas of the face.    (a) Glabellar lines injection technique (Fig. 33.4a, b):  Visualise an imaginary “X” formed by two lines that join  the inner brows with the contralateral inner canthus [11].  The injection must be given at the midpoint of the ‘X’.  Conventionally, the Corrugator Supercilii muscle is  visualised by observing the medial part of the eyebrow  when the patient frowns. Botulinum Toxin is then slowly  injected into the belly [11] of the muscle on either side.  The needle must be maintained at 0.5 cm from the upper  orbital rim, and lie internal to the mid-pupillary line. The  total dose for glabellar line ranges from 10 to 15 U and  can be increased to a maximum of 40 U based on the  severity of the wrinkles.   (b) Forehead lines Injection technique (Fig. 33.5): The fron-  talis muscle is superficial and may be easily identified by  asking the patient to raise and lower the brow. The extent  of muscle movement is then assessed. Injections must be  done in the superficial subcutaneous tissue, over the  entire forehead from medial to lateral. The typical dose  ranges from 2 to 3 U in each point of small dots repre-  sented on the upper and lower aspects of the forehead or    5 U per point of the middle aspect of the muscle, repre-  sented in a big dots as given below in the figure. Frontal  injections and glabellar injections must preferably be  done together, to avoid increased compensatory use of  glabellar muscle, which are mainly depressors [12, 13].  The dose of the injections must be kept small enough to  just weaken the muscle instead of producing total paral-    ysis. This is because the frontalis is responsible for facial  expressiveness, and total paralysis would cause brow  ptosis [14, 15]. It is also important to preserve at least  some frontal is muscle movement, responsible for facial  expression and lift of the eyelids and brows.   Crow feet wrinkles Injection technique (Fig. 33.6a, b):  Three to four injections of Botulinum toxin-A may be    Injection to medial orbicularis oculi muscles  @Association of Oral and Maxillofacial Surgeons of India    Do not inject within 1 cm of the supraorbital rim  ©Association of Oral and Maxillofacial Surgeons of India    administered lateral to the eye, in the ‘crow’s feet’ region  that radiates out from the lateral canthi. Around 8-20 U  may be administered on each side [16]. The injection  must be placed | cm lateral to the orbital rim and must  be above the canthal angle, to avoid upper lateral lag. To  achieve this, one can place a guiding finger of the other  hand at the lateral orbital rim. Owing to the superficial  location of the muscle, the needle need not be advanced  deep into the subcutaneous tissue. Botulinum Toxin has  a wide zone of effect, and therefore a superficial dermal  injection will minimise bruising, but will still give good  clinical results [16].   Elevating Oral commissures and Smile line Injection  technique (Fig. 33.7): Depressor anguli oris is the mus-  cle to be elevated for improving the smile lines. It is indi-  cated in patients with inverted smile line (reverse smile  line), which is caused by pulling the corner of the mouth  inferiorly. To identify the depressor anguli oris muscle,  the patient must frown and the muscle must be simulta-  neously palpated 1 cm lateral and inferior to the oral   Gummy smile or Gingival show correction Injection  technique (Fig. 33.8): In some patients, while smiling,  their upper lip is pulled up, which reveals some amount  of gingival tissue. If this is >1 cm, it is referred to as a  “Gummy smile or Gingival Show”. The levator labii  superioris alaeque nasi elevates the upper lip during  smile. These muscles have their origin on the frontal  process of the maxilla, and insert into the skin of the  lateral aspect of the nose and upper lip. If only one mus-  cle contracts, it results in a ‘snarl’, and this muscle has  been referred to as the “Elvis” muscle [16]. Normally,  1-2 U of the Botulinum neurotoxin is injected on each  side in the muscle. Care should be taken because this  injection can produce elongation of the upper lip.  Platysmal wrinkles Injection technique (Fig. 33.9): The  platysma forms horizontal lines or wrinkles. Into every  horizontal crease, an intradermal injection of 1-2 U may  be injected for every 1.0—1.5 cm [16]. There may be sev-  eral creases, but each treatment session must not use  more than 15-20 U. In these areas, careful injections are  absolutely essential, as these muscles are cholinergic,  and deep injections may affect swallowing. If the injec-  tions are placed at deeper levels, or high volumes are  used, a weak or diminished swallow may result.  Masseteric Hypertrophy Injection technique (Fig. 33.10):  The masseter can give masculine characteristics, such as  square jawlines and wide mandibular borders. This is  enhanced when the muscle hypertrophies, and may not  be attractive in women. Bruxism and clenching of teeth  can lead to hypertrophy of the masseter muscle, which in  turn increases the horizontal width of the mandible [16].  While injecting into the masseter, one finger may be    Alternative technique: Inject inferiorly on mandibular ramus  ©Association of Oral and Maxillofacial Surgeons of India    placed along the lower border of the mandible, one fin-  ger along the posterior border and one at mandibular  angle. This may be done with the patient clenching, as    this marks the perimeter of the muscle. While injecting  bone should be felt by the needle and withdrawn slightly  just above the bone and deposit 4—5 U along the marked  lines. Depending on the volume of hypertrophy, around  20 U may be injected [16]. Over-injection at the masse-  ter region may result in problems with bite or chewing.  Frey’s Syndrome or Gustatory sweating Injection  Technique (Fig. 33.11): This is a condition in which mild  to profuse sweating occurs in the cheek or malar area  while eating. A diagnostic test called “starch-iodine test”  [16] can be performed prior to injection of Botulinum  toxin. Povidone iodine is applied over the cheek and corn  starch is sprinkled. The patient is advised to eat, to stimu-  late the salivary gland and left to dry for a few minutes.  The corn starch turns black in the area of sweating [16],  and a grid is drawn along this area. Once the test is con-  firmed, usually 30-SO U is injected along the grid as  shown. The botulinum toxin blocks acetylcholine, which  is the neurotransmitter that stimulates sweating.    Apply pressure at the site before and after treatment. Cold  packs may also be used.   The use of small syringes and fine-gauge (30 g) needles  can reduce pain and bruising at the injected site.   Using topical anaesthesia (EMLA—Eutectic Mixture of  Local Anaesthesia) reduces pain while injecting.    e Injections should be symmetrical regarding doses, mus-  cles and areas. This is important for the natural balance of  the facial structures and to avoid asymmetries.   e Since the results are expected for 4-6 months, treatments are  usually repeated twice a year, for maintenance of the results.   ¢ There are isolated few reports of systemic adverse effects  after injections with the use of doses larger than those  usually recommended for cosmetic purposes [17].   ¢ The most common injection-related side effects are pain,  transient edema at the injected site, erythema, haemato-  mas and ecchymosis [13, 17].   ¢ Common technique-dependent complications include  eyelid ptosis, asymmetries and excessive brow elevation.   ¢ In the lower face, complications are related to high doses  can cause undesirable paralysis of the musculature, result-  ing in asymmetric smiling and complications due to the  incompetence of the sphincter function of the mouth.   e In the neck, complications can be dysphagia and diffi-  culty in the movements.    Throughout the past decades, there have been major changes  and advancements in the injectable preparations used for soft  tissue augmentation. Introduced by Dr. Arnold Klein [1] in  the 1980s, for lip augmentation, collagen has progressed to  the broader concept of volumising the face and to correct the  subcutaneous atrophy due to ageing and fat loss.   Following extensive clinical trials in the late 1970s, the  FDA first approved the use of bovine collagen in 1981, which  greatly advanced the field of soft-tissue augmentation. Over  the past 10 years, several types of facial fillers have been  approved in the United States and Europe, and there is a con-  stantly evolving and expanding assortment of the dermal  filler materials and devices for soft tissue augmentation [18].   Hyaluronic Acid (HA), which was introduced as a facial  filler in 2003, brought about a much needed change from the  allergies being reported due to bovine collagen [18].  Hyaluronic Acid is a member of the glycosaminoglycan  family and a natural component of human connective tissue.  The HA molecule is identical across all species and lacks a  protein component, thus it has little to no potential for immu-  nologic reaction in humans. It is composed of repeating  disaccharide units, stabilised with cross-linked hydroxyl  groups that bind water to create volume. This gives a plumped  appearance to the skin. HA in the skin decreases with age  and sun exposure, reducing the skin’s water-binding capacity  and turgor, ultimately leading to skin wrinkling and sagging  [19]. HA can absorb up to 1000 times its molecular weight of  water, and Hyaluronic Acid fillers volumise the face by  replacing body Hyaluronic Acid and restoring hydration [5].    Studies have shown that hyaluronic acid requires less injec-  tion volume as compared to bovine collagen for optimal cos-  metic results, and HA is also found to be more effective at  maintaining the cosmetic correction [20, 21].   The U.S. Food and Drug Administration (FDA) has now  approved various types of Hyaluronic acids, bio-stimulatory  products like calcium hydroxyapatite and poly-t lactic acid,  as well as polymethylmethacrylate as a substitute for fillers.   Fillers are categorised as permanent, semi-permanent and  temporary. The majority of injectable fillers are temporary,  lasting from several weeks to several months, although some  reportedly last 9-12 months. Many of these processes require  ongoing treatment to maintain the desired appearance [22].    Based on their duration of action, fillers may be classified as  follows:    Temporary (3-12 Months) These are mainly used to replace  collagen in the skin, which weakens with age and loses its  elasticity. Collagen has three main sources—bovine, porcine  and human. Bovine collagen is very similar to the human  molecule and is widely used. It only has specific differences  in the end peptides (telopeptides), which are removed in pro-  cessing, leaving a core protein similar to that of a humans  [23]. Hyaluronic acid is the most commonly used Filler  material of this category.    Semi-Permanent (I—5 Years) Calcium hydroxyapatite is one  of the commonest semi-permanent fillers. It creates a stable  scaffold for soft tissues to grow. Calcium hydroxylapatite may  be injected into the deep dermis, where the microspheres are  held in place until they are resorbed and collagen deposition  occurs. This results in formation of non-scar-tissue type of col-  lagen, which provides volume in the area under treatment [24].    Permanent (>5 Years) These are mostly synthetic implants,  which are made of Polymethylmethacrylate (PMMA) micro-  spheres. PMMA microspheres may be mixed with denatured  bovine collagen and lidocaine, and suspended in a phosphate-  buffered saline solution. Since PMMA is inert, it is well toler-  ated by the body and does not induce allergic reactions [25, 26].    Preparation of the Patient before Injection of Fillers:  The patient’s face is washed gently to dry and disinfect the  skin. This is done using propanol solution. Since the dermal  fillers are very painful while injecting, application of the  topical anaesthesia around the area of injection using EMLA  (Eutectic Mixture of Local Anaesthesia) for 30-45 min prior  or particular branch of Maxillary division or Mandibular  division of the trigeminal nerve is anaesthetised using 2%  Lignocaine as a local anaesthetic injection.    Hyaluronic acid is available in syringes in a sterile packed  container. These have 26-30 gauge needle, with a length of  1-1 inches.   These are injected at the subdermal planes in various  fashion which are mentioned in Box 33.2.    Linear Threading: In this technique, fillers are injected  in a needle and thread fashion. The needle is inserted and  withdrawn repeatedly along a straight line. It has two    1. Anterograde Injection: The filler is injected while the  needle is being advanced, and the filler is therefore easily  tracked in the front of the needle.    2. Retrograde Injection: The filler is not injected simultane-  ously during needle advancement. Once the needle is  slowly withdrawn, the filler is injected.    Depot: In this technique, a small amount of the filler is  deposited in the correct plane.    Serial Puncture: In a single wrinkle or fold, multiple  closely spaced depot injections are placed.    Fanning: It is done through one point of entry and the nee-  dle is rotated like a fan in multiple directions, and the fillers  are deposited in a retrograde way. It is important to stop  injecting as the needle comes close to the insertion site in  order to avoid build-up of fillers at the point of entry.    Grid: It is injected as linear threads intersecting perpen-  dicular to each other point of entry.    Ferning: [16] This is similar to retrograde injection. The  needle is inserted on either side of the central tract, and the  fillers are deposited in a branch-like fashion almost like the  branches of a fern.    (a) Glabellar and Forehead region (Fig. 33.13a,b): The  Glabellar region is the most prominent site for wrinkling  and very well shown even in a mild expression. There  are vertical lines of wrinkling, which result from con-  traction of the corrugator supercilii muscles, and hori-  zontal lines which occur due to contraction of the  procerus muscle. Before injecting, the patient should  frown the brow and the needle is inserted at the subder-  mal plane and injected in a linear fashion and it is also  deposited deep and parallel to the wrinkle. Small depots  or serial puncture fashion of fillers are injected along the  line of the wrinkles throughout its entire length. Gentle    rub or massaging to be done to distribute the filler uni-  formly. In the case of bruising, icepacks can be used.  Injecting into a vessel must be avoided as this can lead to  the formation of emboli.   (b) Nasolabial Fold (Fig. 33.14a,b): The nasolabial fold is  defined as the groove from corner of the alar base to the  margin lateral to the angle of the mouth. The nasolabial  groove must never be eliminated completely as this can  result in an unaesthetic appearance. Injection may be  done using serial puncture, linear threading, cross-hatch-  ing, or fanning. Only the medial part of the fold must be  augmented, with injections perpendicular to this. This is  best done by imagining a tall, thin, triangular deficit in  front of the fold that needs to be filled. To prevent bruis-  ing, ice and pressure may be applied. Initially, hyal-  uronic acid swells and may appear as a firm mass on  palpation but gradually blends in after the first week.   (c) Lip Augmentation (Fig. 33.15): This is one of the most  common cosmetic procedures done using Hyaluronic  acid filler for augmenting or everting the lips. The areas  to be augmented are the outline of the lip, body of the lip  or both. There is a potential space in the body of the ver-  milion, which, if correctly entered, will allow the filler to    move within it along the entire lip margin. Dermal fillers  injected in the body of the lips can augment, rejuvenate  and improve the symmetry of the lips. Philtral columns  can get flattened with age. These can be accentuated by  injecting along the border of the vermilion and philtral  region to give a more prominent philtrum and cupids  bow with eversion of the lip. The philtrum may be  pinched after injection to accentuate the ridges. Injections  are generally placed superficially in to the subcutaneous  plane. Massaging or a gentle rub after injection helps to  distribute the filler evenly. Injection may be performed in  an anterograde fashion, from lateral to medial, and the  filler can be tracked along the vermillion.   Tear Trough Deformity (Fig. 33.16): Tear Trough is usu-  ally referred to as the crease at the medial segment of the  inferior orbital region. As ageing occurs, the infraorbital  rim becomes more skeletonised and depressed. To cor-  rect this sunken appearance, HA may be injected into the  semicircular depression under the eyes. Normally a  30-gauge needle, 2.5 cm long, is used to inject in the der-  mal layer of the lower eyelid to avoid bruising, as this  area is highly vascularised. The needle is then inserted  upwards at an angle, till it reaches the top of the orbital  rim. The finger of the opposite hand may be used to direct  the needle by positioning it at this point. The tip of the  needle must touch the bone and its precise location must    be verified prior to injection. The filler is injected slowly  and deeply into this area. Massaging may be done at the  injected area to avoid irregularities. If the HA is depos-  ited too deep, a “Tyndall effect” [16] may be observed.  Hyaluronic Acid can occasionally increase fluid retention  around the periocular area, and lead to infraorbital swell-  ing, edema or discolouration in the medial portion of the  orbicularis muscle. If this occurs, subcutaneous hyal-  uronidase injections may lyse the Hyaluronic Acid and  reduce the swelling.   (e) Injection technique to increase the cheek volume  (Fig. 33.17): In some patients, fat loss or volume deficit  can cause cheek hollowing. The loss of buccal pad of fat  causes wrinkled cheeks, exaggeration of nasolabial folds  and jowling of the skin at the lower border of the mandible.  The submalar region (below the zygomatic arch) and buc-  cal region (lateral to the nasolabial fold) are areas that need  attention. The injection technique should be administered  in a grid or fanning pattern. The injections must be admin-  istered at the dermal—subcutaneous plane. Massaging after  injection can help smoothen irregularities.    Some of the most common conditions to be avoided for  fillers include:    Botulinum Toxin Type A and Hyaluronic acid dermal fillers  are very safe and effective under a trained physician or sur-  geon for therapeutic and cosmetic use. Wrinkles especially  those which are located in the face and some asymmetries,  mainly caused or worsened by the repeated contraction of  facial muscles and ageing process can be effectively treated  by these methods.   Proper knowledge of the anatomy of facial muscles and  proper techniques are important to achieve predictable results  and avoid complications. Informed consent for the procedure  must be obtained from the patient after explaining the risks and  the outcome, before commencing the treatment. Though  Botulinum toxin and dermal Fillers give temporary results, they  are safe and very effective in achieving aesthetic outcome.    Fig. 33.15 Injection technique for philtrum, lip line and the body of the lip. (a) anterograde filling (b) retrograde filling (c) both anterograde and  retrograde filling (d) antero retrograde with fanning if necessary (e) depot and serial puncture filling (f) anterograde retrograde serial and depot  filling    AED:  Tear trough deformity  @©Association of Oral and Maxillofacial Surgeons of India    Case Scenarios normal size of the tooth. Treatment Plan (Fig. 33.18b1, b2,  b3 and b4): locating the levator labii superioris muscle and  Case 1 (Fig. 33.18a,b,c) injecting Botulinum toxin Type A with a dose of 5 U on both    the sides. The injection point is located at the junction  A 43-year-old female complaining of excessive tooth and between lip and the ala of the nose. Post-operative findings  gingival exposure on smiling. Clinical features (Fig. 33.18a): (Fig. 33.18c): no gingival show on smiling.  excessive gingival show on smiling normal lip length and    Fig. 33.18 (a) Clinical features with excessive Gingival show. (b1, b2, b3, b4) Intraoperative. (c) Postoperative, absence of Gingival show    Fig. 33.19 (a) Clinical feature with forehead wrinkling. (b1, b2) Intraoperative. (c) Post-operative, absence of Wrinkling    A 47-year-old male, complaining of excessive wrinkling in  the forehead on looking upwards and frowning with ageing  appearance. Clinical features (Fig. 33.19a): wrinkling and  folds found on the forehead on upward starring and frowning.  Treatment Plan (Fig. 33.19b1, b2): locating the frontalis mus-  cle and injecting Botulinum toxin Type A with a dose of 5 U  on both the sides at 3 different points marked and above | cm  from the supraorbital margin. The injection point is located  midway between supraorbital margin and frontal hairline.  Post-operative findings (Fig. 33.19c): absence of wrinkling.    . Shuster S, Black MM, McVitie E. The influence of age and sex    on skin thickness, skin collagen and density. Br J Dermatol.  1975;93:639-43.    . Ezure T, Yagi E, Kunizawa N, et al. Comparison of sagging at the    cheek and lower eyelid between male and female faces. Skin Res  Technol. 2011;17(4):510-5.    . Gerhardt LC, Strassle V, Lenz A, et al. Influence of epidermal    hydration on the friction of human skin against textiles. J R Soc  Interface. 2008;5:1317—28.    . Dover N, Barash JR, Hill KK, Xie G, Arnon SS. Molecular char-    acterization of a novel botulinum neurotoxin type H gene. J Infect  Dis. 2014;209: 192-202.    . Lebeda FJ, Hack DC, Gentry MK. Theoretical analyses of the    functional regions of the heavy chain of botulinum neurotoxin.  In: Jankovic J, Hallet M, editors. Therapy with botulinum toxin.  New York: Marcel Dekker; 1994. p. 51-61.    of botulinum toxin on the musculature. In: Hexsel D, Almeida AT,    editors. Cosmetic use of botulinum toxin. Porto Alegre: AGE; 2002.  p. 99-103.   Wollina U, Konrad H. Am J Clin Dermatol. 2005;6(3): 141-50.  Ascher B, Talarico S, Cassuto D, Escobar S, Hexsel D, Jaén P, et al.  International consensus recommendations on the aesthetic usage  of botulinum toxin type A (Speywood Unit)—part II: wrinkles on  the middle and lower face, neck and chest. J Eur Acad Dermatol  Venereol. 2010;24(11):1285—-95.   Carruthers A. Botulinum toxin type A: history and current cosmetic  use in the upper face. Dis Mon. 2002;48:299-322.   Hexsel D, Mazzuco R, Zechmeister M, Hexsel CL. Complications  and adverse effects: diagnosis and treatment. In: Hexsel D, Almeida  AT, editors. Cosmetic use of botulinum toxin. Porto Alegre: AGE;  2002. p. 233-9.   Benedetto AV. The cosmetic uses of botulinum toxin type A. Int J  Dermatol. 1999;38:641-55.   Lorenc ZP, Smith S, Nestor M, Nelson D, Moradi A. Understanding  the functional anatomy of the frontalis and glabellar complex for  optimal aesthetic botulinum toxin type A therapy. Aesthet Plast  Surg. 2013;37(5):975-83.   Kontis TC, Lacombe VG. Cosmetic injection technique. New York:  Thieme; 2013. p. 23-4.   Klein AW. Complications with the use of botulinum toxin. Dermatol  Clin. 2004;22(2):197—205.    Narins RS, et al. A randomized double-blind multicenter compari-  son of the efficacy and tolerability of Restylane versus Zyplast  for the correction of nasolabial folds. Dermatol Surg. 2003;29(6):  588-95.   Donofrio L. Fat distribution: a morphologic study of the aging face.  Dermatol Surg. 2000;26:1107-12.   Guttman C. A generation speaks: dermatology answers growing  desire to fight aging skin. Dermatology Times, pp. 56-60; 2004.  Guttman C. Advances in anti-aging: new techniques technology  should match demand. Dermatology Times; 2004.   Glogau R, Narins R, Weiss R. Advances in cosmetic procedures.  In Fall clinical dermatology conference supplement proceedings.  Supplement to skin and aging, pp. 20-27; 2004.   Bisaccia D, Scarborough D. The esthetic correction of the aging  mouth. Cosmet Dermatol. 1992;11:8-11.   Elson M. Soft tissue augmentation techniques: update on available  materials. Cosmet Dermatol. 1999:13-5.   Lemperle G, Romano JJ, Busso M. Soft tissue augmentation with  Artecoll: 10-year history indications techniques and complications.  Dermatol Surg. 2003;29(6):573-87.    Open Access This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.  org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropri-  ate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.    The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in    a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.   In the past few decades, maxillofacial surgeons have played  a pivotal role in enhancing the aesthetic value of the face  through many surgical and non-surgical procedures, with  hair transplantation being one of the popular choices which  has seen an exponential demand in the last decade. Though  hair restoration procedures were being performed for many  decades ever since Dr. Norman Orentreich in 1959 published  them in the annals of the New York Academy of Sciences,  there has been many advances to the originally described  punch grafting which has become obsolete and has been  replaced by the so-called micrografts via the two basic tech-  niques of follicular unit transplantation (FUT) and follicular  unit extraction (FUE). The success of the above techniques is  in part attributed to the theory of donor dominance which  postulates that the hair taken from the donor area of the pos-  terior scalp will continue to grow without getting hit by fac-  tors which were responsible for the thinning out of hair in the  frontal areas [1].   Apart from hair transplant being a promising procedure  for male pattern and female pattern alopecia, it has been  applied to other causes of hair loss too; traumatic and burn  scars on hair bearing areas, alopecia following surgical pro-  cedures (i.e. Craniotomy, rhytidectomy procedures), redo  hair transplantation, congenital reasons like cleft lip sce-  nario. Currently the scope for hair transplantation is expand-  ing with the demand from patients who want to strengthen a    Electronic Supplementary Material The online version of this chap-  ter (https://doi.org/10.1007/978-98 1-15-1346-6_34) contains supple-  mentary material, which is available to authorized users.    S. R. Pothula (4)  Oral and Maxillofacial Surgery, Pioneer Advanced Hair Transplant  Centre, Bengaluru, Karnataka, India    © The Association of Oral and Maxillofacial Surgeons of India 2021    weak hairline, desire to lower the hairline or fix missing  facial hair on the moustache, beard, eyebrow or eyelashes.  As the field of hair transplantation continues to evolve at  a breakneck speed with specialists from multiple specialities  performing this scientific artistry, it’s all the more pertinent  that we as maxillofacial surgeons are abreast of the current  principles and practice of this hair restorative surgery.    An understanding of the surgical anatomy of the scalp is nec-  essary to avoid complications and to optimise your perfor-  mance for hair transplantation.   Scalp consists of five distinct layers with the most super-  ficial layer being the skin which comprises of epidermal and  dermal layers. These layers contain hair follicles, sebaceous  and sweat glands with rich vascular supply. The second layer  of scalp is made up of connective tissue, which is well vascu-  larised and heavily innervated by sensory nerves. The deep-  est portion of the hair follicle, bulb and papilla, may extend  through the skin into this layer (Fig. 34.1a). Thus, when  obtaining donor grafts, effort should be made to incorporate  the upper part of dermal layer to obtain the entire hair folli-  cle. The third layer also called galea aponeurotica is a tendi-  nous tissue connecting the two bellies of the occipitalis and  frontal muscles. Loose areolar connective tissue is the next  layer which contains numerous potential spaces, capable of  great distension thus allowing for exceptional mobility of  scalp. Unfortunately, these spaces are also capable of poten-  tial space for haematoma collection and spread of infections.  The deepest layer of the scalp defines the pericranium, which  is analogous to periosteum throughout the body.    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1-15-1346-6_34    708  a b  Greater occipital  nerve  Epidermis  Dermis  Lesser occipital  nerve  Subcutaneous fat    Fig. 34.1 (a) Hair follicle extending into dermis; note the layers of the scalp. (b) Arteriovenous supply of the scalp with sensory innervation. (c)    The arterial supply to the scalp arrives from branches of both  external and internal carotid arteries. Branches of the exter-  nal carotid artery in order from posterior to the anterior  include the occipital, posterior auricular and superficial tem-  poral arteries. The supratrochlear and supraorbital arteries    are branches of the internal carotid artery. The veins of the  scalp follow the same basic network of the arteries and drain  into the jugular veins (Fig. 34.1b). All of these vessels freely  anastomose in the connective tissue layer of the scalp.  Awareness and approximate location of the main branches  are very important during the hair transplant surgery not only  to avoid haemorrhage or haematoma but also to prevent isch-    emia to the follicles. Occipital artery which enters the scalp  immediately above the external occipital protuberance at the  superior nuchal line can easily be injured if depth control is  not maintained. If arterial haemorrhage is encountered, elec-  tro cautery and suture ligation are adequate to secure homeo-  stasis. Damage to vessels could likely lead to the formation  of donor area scar.   Sensory innervation of the scalp arises from all three  branches of trigeminal nerve antero-laterally with the fore-  head getting its supply from the supraorbital and supratroch-  lear branches of the ophthalmic division, while the anterior  temporal scalp is supplied by the maxillary division and the  mandibular division goes onto supply the temporoparietal  zone of the scalp through its auriculotemporal nerve. The  spinal cutaneous nerves of the cervical plexus (c2 and c3)  come to supply the area posterior to the auricle via the greater  and lesser occipital nerves. These nerves are found in the  connective tissue just superior to the galea.    Typically, the areas of male pattern hair loss are horseshoe  shaped and are divided into three zones [2] (Fig. 34.1c)    1. Frontal—extends from the hairline to the mid-scalp and  is curvilinear. Has a frontal hairline zone anteriorly with  the line being irregular like coastline of the sea with  mounds and recessions. The follicles in this zone is  mainly single hair follicle for the first two to three rows  generally blending into multiple follicular units posteri-  orly giving rise to the density effect known as shingling.  The frontal core zone is a small area in the central aspect  of the frontal region which is circular to oval and is very  important in framing the face receiving the highest den-  sity of grafted hairs.   2. The mid-scalp—is at the top of the head. This horizontal  area is bordered on both the sides by the temporal parietal  fringes and is sandwiched between the frontal zone ante-  riorly and the vertex posteriorly.   3. Vertex or crown—the most posterior area being rounded  and characterised by whorl arrangement of hair is the  toughest area to transplant.    The temporal fringe is the lateral hair zone present on the  sides of the scalp anterior to the tragus of the ear and poste-  rior to this is the parietal fringe.   The frontotemporal apex is the area usually devoid of hair  at the junction of the lateral frontal hairline and temporal  fringe. This coincides with the deepest point of the recession  on the forehead and is aligned with the lateral canthus of the  eye.    Hair consists of a living part under the skin extending into  the dermis known as follicle and a non-living keratinised part  above the skin, the so-called hair shaft (Fig. 34.2). The shaft  has three further layers namely the outer protective cuticle,  inner cortex and in certain cases the medulla forms the core,  and they mainly help in protection and anchorage of the hair.   The growing structure of the hair is the follicle with the  upper part being constant and consists of the top infundibu-  lum at the opening of sebaceous gland and isthmus in the  middle where the piloerector muscle comes to insert. The  lower part of the follicle known as the bulb is very vital as it’s  the one involved with regeneration and most of the stem cells  are located here. Hence, while implanting holding, the graft  above or beside the bulb is vital to ensure sustenance of  regenerative potential.    The unique language of hair transplant surgeons consist of a  few common words to communicate within the speciality [3]  (Box 34.1).    Box 34.1 Hair Transplant Surgery: Terminology  Follicular unit graft (FU): The natural Bundle of hair  strands consisting of one, two or three hairs woven  within a single unit and held by connective tissue ele-  ments as the follicle. The graft containing two or three  follicular units becomes a multi follicular unit graft.   Micrograft: The follicular unit which has single hair  graft within it is referred to as a micrograft, and the  same is preferred for frontal hairline implantation.   Minigraft: The follicular unit which has more than a  single hair graft and houses four to six hair grafts prior  to cutting with microscopes are minigrafts.   FUT: The grafts are obtained from the harvested  strip through slivering and dissection of individual fol-  licles under magnification.   FUE: The grafts are obtained individually in the  donor area one at a time utilising a punch and handheld  extractor.   Stick and place implantation: Refers to implanta-  tion made immediately as the recipient site slit is made  with a needle or blade.   Pre slit implantation: Refers to implantation made  after all the recipient site slits are made with a blade or  needle.   Coronal slits: Refers to slits oriented along coronal  from side to side.   Sagittal slits: Refers to slits oriented along sagittal  plane from front to back.    Hair is cylindrical, outgrowths on the skin made up of kera-  tinous filaments. The normal human scalp contains between  100,000 and 140,000 follicles with hair being arranged in  follicular units, small groups of 1-4 hairs each. There are  approximately 50,000-—60,000 follicular units on the human  scalp.   Testosterone is the main regulator of hair growth with the  androgens binding to receptors in the dermal papilla influ-  encing the growth. Human hair does not grow constantly and    evenly but grows in phases and in cycles which are reproduc-  ible. Anagen is the growing phase of hair that accounts for  85% of the hair growth, during which hair grows at 0.5 inch  per month for up to 10 cm per year with adequate blood sup-  ply providing nutrients and minerals to the hair. This phase  lasts for anywhere between 3 and 6 years. As long as this  phase persists, the hair stays on the scalp and is genetically  determined. Anagen is followed by catagen and the later  phase onset signals the end of active hair growth. During this  transitional phase which lasts for 1-2 weeks, the production  of hair stop and hair follicle start to shrink in size and nearly  2-3% of the hairs are in this phase. Telogen is the final phase  of the hair cycle where the aged hair fall out and new ones  push themselves out of the skin. This final phase lasts for  nearly 3 months with around hundred hairs being shed per  day and nearly 10-15% of the hairs are in this phase at any  point in time (Fig. 34.3).   People often confuse with hair fall to hair loss. Hair fall is  common in every individual. Around 10-20% of total hair  will be under shedding process. That hair will grow back in  3 months. On average 80-60 hair strands fall is considered as  normal.   Male pattern hair loss or androgenetic alopecia as the  word suggests is a result of both androgens and genetic fac-  tors which work together causing the clinical effect of bald-  ness [4]. Though there are many reasons for hair loss,  androgenetic alopecia is the most common reason and  accounts for 95%. Fortunately, it can be treated with hair  transplant surgery. The diagnosis of androgenetic alopecia is  supported by a family history of hair loss, although a positive  history is not always identified. There is a slightly greater  incidence of having a positive history on the mother’s side  but the inheritance of male pattern hair loss can come from  either side of the family.   In androgenetic alopecia, there is change of hair from ter-  minal hair to vellus hair. There happens to be a gradual evo-  lution of this pattern, with each subsequent cycle of the new  hair being fine and thin leading eventually to various grades  of alopecia. It initially starts with the frontal hairline reces-  sion and regression, followed by loss of more temporal hair  and simultaneous thinning of the vertex hair. Norwood clas-  sified approximately 7 different types of male pattern hair  loss. Identification of these types is key to an understanding  of proper planning of hair transplant surgery.   Testosterone gets converted to dihydrotestosterone (dht)  both systemically and in the process of intrafollicular con-  version under the influence of the enzyme 5-alpha reductase  leading to its binding with androgen receptors of the follicu-  lar cells in genetically predisposed men leading to inhibition  of protein synthesis by shortening the anagen phase, thereby  producing finer hairs with shaft becoming thinner; this  stunted hair follicle growth leads to miniaturisation of folli-  cles till they become extinct establishing balding [5].   2. By ensuring normal supply of balanced nutrients to  the hair roots   3. Proper blood circulation to carry the nutrients to the  roots in the scalp   4. Maintaining good health through general well-  being of the individual    Clinical studies have given us an understanding that hair  can be grown back if the following four things are ensured  (Box 34.2):   Hair loss is not a disease but a condition where anagen or  the growth phase reduces and the telogen or fall phase is  extended. This forms the basis of hair loss in alopecia condi-  tions other than androgenetic alopecia. The factors leading to  hair loss could stem from internal/external factors.    Internal Factors There are many factors which internally  lead to deficient states harming the hair growth. A few of  them which are relevant today are iron deficiency, calcium  deficiency, zinc deficiency, general debility, anaemia, hypo-  thyroidism, deficiency of the fat soluble vitamins, thyroid  problems, insulin resistance, metabolic disorders like gout  and PCOD, prolonged illness, emotional turmoil following  surgery and individuals with seborrheic scalp.    External Factors The lifestyle and environmental factors do  influence the hair health and growth cycle. The common  causes are smoking including passive smoking, stress, alco-  hol intake, lack of sleep, crash dieting, fad diets, high-protein  diet, exposure to extremes of heat or cold, less intake of flu-  ids, poor scalp hygiene, dust, pollution, fumes and exposure  to endocrine disrupting chemicals.    The most popular classification of the male pattern hair loss  is the Norwood classification system (1975) which is a  refined version of the original Hamilton system (1941) [6].    Type 1 presents the normal hairline with minimal  recession of the frontotemporal area.   Type 2 patients present a symmetrical and mild reces-  sion of the frontotemporal area along with thinning  of the hair.   Type 3 patients define balding with minimal or no in  the frontal areas and a deep recession.   Type 4 patients present with significant recession and  loss of both frontal and vertex hair with a bridge of  her between the two still retained.   Type 5 category patients present a progression of the  type four category with only thin and narrow bridge  of hair between the frontotemporal and the vertex  areas.   Type 6 represents the loss of hair that separates the  frontal and the posterior vertex areas with further  progression in lateral and posterior zones.   Type 7 represents the most severe form of balding with  only a band of hair remaining in the low occipital  and temporal areas with extensive miniaturisation  of the hair.    Basically, in the above classification, the two areas of hair  loss—a bitemporal recession and thinning crown gradu-  ally enlarge and coalesce until the entire front, top and  crown of the scalp are bald.    To regain the crowning glory, medical treatment gives  good results up to type 3 patients while hair transplantation  is the only choice for patients between types 4 and 6.   Routinely, clinicians come across variations of the clas-  sification which fall outside the Norwood classification, they  are as follows: Differential use pattern alopecia, diffuse and  patent alopecia.   Type I (mild), type II (moderate) and type III (exten-  sive). In all three Ludwig stages, there is hair loss on the  front and top of the scalp with relative preservation of the  frontal hairline. The back and sides may or may not be  involved.   In Ludwig type I, there is early thinning that can be easily  camouflaged with proper grooming. Type I patients have too  little hair loss to consider surgical hair restoration.   Women with type II hair loss have significant widening of  the midline part and noticeably decreased volume. Hair  transplantation may be indicated if the donor area in the back  and sides of the scalp is stable.   In Ludwig type III, there is a thin, see-through look to the  top of the scalp. This is often associated with generalised  thinning over the entire scalp. Often patients that have pro-  gressed to this stage have too little donor hair to make surgi-  cal hair restoration worthwhile.   All women experiencing hair loss should have an accurate  diagnosis made, preferably by an experienced dermatologist.  This is particularly important since the diffuse hair loss that  women typically develop, can occasionally be caused by a  number of treatable medical conditions. Regardless of the  extent or cause of hair loss, only women with stable hair on  the back and sides of the scalp are candidates for hair  transplantation.   Other infrequent alopecias observed among the patients  visiting hair clinics are as follows:   Alopecia areta: it’s an autoimmune disorder which starts  with small round and punched out areas with no hair.  Lesion has very smooth skin and not even a single hair is  present in the lesion.   Alopecia universalis: there is total hair loss in the body  including the eyebrows.    Turban alopecia: caused due to tight turban usage. It affects  frontal and parietal areas mainly and is seen among  Sikhs.   Trichotillomania: a psychiatric disorder where the individu-  als deliberately pull their hair every day leading to hair  loss in those areas.    Only 2 drugs have been approved by FDA and have proven  their efficacy in the management of hair loss with good  success.    This is a direct hypertrichotic drug, which was initially  approved as an antihypertensive agent and was found to  have side effect of hypertrichosis. Today, it is available as  an over the counter drug with 2% formulation for women  and 5—10% formulation for men as topical solution and  gel. It improves hair count, weight and growth of hair. Post  transplantation too it has been found to decrease the shed-  ding of hair and enhanced the time to onset for hair growth.  According to few studies, minoxidil acts as a vasodilator  by opening up the potassium channels and thereby  enhances the vascularity of the hair bulb which in turn pro-  motes hair growth. However, the exact mechanism is  unknown. This topical product needs to be applied to the  scalp and not the hair and patients need to be informed  about the initial increased shedding of weak hair in the  first 4-8 weeks. Further, the patients need to be counselled  to apply the product twice a day to maximise the efficacy  and to wait for a timeframe of at least 4-5 months prior to  seeing the results.    Finasteride is a drug which is used only in men for reversal  of miniaturised hair follicles. This drug is a competitive  inhibitor of the enzyme 5-alpha reductase which blocks the  conversion of male hormone testosterone to dihydrotestos-  terone, and thereby works on the pathogenesis of androge-  netic alopecia. It is to be taken orally once a day daily at  1 mg. Finasteride can cause loss of libido and oligospermia  in few individuals. However, this side effect is reversible  once the drug is discontinued.   Other medicines like Dutasteride though being a potent  inhibitor of 5-alpha reductase is not that popular in the mar-  ket as it has got adverse effects. Few natural products like  saw palmatto can be used in young individuals who refuse to  take finasteride.    It entails giving vitamins with calcium supplements on a  single day, followed by iron and mineral combination prod-  uct on one other day of the week and finally amino acid  blend; the three regiments are also advocated that their intake  be on alternative days as different nutrients and the daily  dosing is avoided. The basis of this therapy is that hair  requires nutritional support during their anagen growth phase  and also for its maintenance; without nutrients, hair cannot  get support and the stimulated hair growth to demonstrate  disappointing outcomes. This therapy is the result of pio-  neering work on the role of nutritional supplements in hair  growth.   Platelet-rich plasma (PRP) is an autologous biological  modifier which has many concentrated growth factors in it  and has demonstrated good results in reducing hair loss and  has shown to enhance hair counts. It is prepared in a three-    step process where blood is drawn, processed and injected  into the scalp. It is injected into the scalp once every fort-  night for 4—6 sittings and this can be combined with the stan-  dard therapy.    It is important to begin the consultation by knowing the gen-  eral health of the patient with a focus on endocrinal condi-  tions affecting hair namely the thyroid disease, any  uncontrolled diabetes, polycystic ovarian disease in the case  of females and also enquiring specifically about family his-  tory of hair loss, past medical management, understanding  personal hair care regimen and any past hair transplants  done.   The next focus of the clinician during consultations  should be on the expectations and motivation levels of the  patient trying to drive home the message that it’s a progres-  sive condition especially in younger patients who are  demanding and want a low hairline. It’s important to have a  family member during consultation and ensure that they  understand that any future hair loss is understood and you are  only trying to frame the face. The pattern of the hair loss also  needs to be well documented.   The donor site assessment will verify the presence of any  white hair, check the elasticity of the scalp, the density of the  hair follicles per square centimetre, note the calibre of the  hair (thick vs. thin), presence of curly or straight hair, rule  out any existing scars and skin pathology including dandruff  and infections.   The assessment of the recipient site will focus on the  quality and quantity of remaining hair, ascertaining the grade  of balding and the pattern of hair loss, previous results of hair  transplantation, the skin to hair contrast, direction of the  existing hair and existing skin condition. Based on the priori-  ties of the case and having assessed the areas requiring hair  transplantation, the number of follicular units required per  square centimetre (around 30/cm7?) is calculated to arrive at  the number of follicular units to harvest.    Hair transplantation as performed today is basically micro-  follicular unit transplantation and few clinicians call it as  hair restoration as there are many methods to achieve the  results.   In the early days, hair transplant concept started with flap  rotation techniques requiring procedures to be performed  under general anaesthesia. These invasive techniques did not  gain popularity as the results were not satisfying and the pro-  cedures left disfigurement in few individuals. Later on dur-    ing the evolution of techniques, macro and micrografts being  5-6 mm in size were introduced which were harvested with  biopsy punches and the resulting grafts were implanted.  These plug like grafts being unnatural in appearance gave a  classical doll’s hair appearance after growth and got phased  out with further refinement of hair transplant procedures.   By around 1963, follicular unit transplantation or strip  technique was introduced which became a workhorse of hair  transplantation until recently and is still considered to be the  gold standard method for hair restoration. In the year 2002,  Rossman and Bernstein refined the punch method of harvest-  ing the follicles and named it follicular unit extraction which  has seen an exponential growth in the recent years and is  today the most popular technique of hair transplantation.   The principle behind hair transplantation is quite simple.  The hair that grows on the back and sides of the scalp tends  to be permanent in most of the individuals. These occipital  and parietal hairs are resistant to androgenic alopecia and are  used to implant into the frontal or vertex area which will con-  tinue to grow as long as occipital hair grow, but in few indi-  viduals with advanced grades even these donor hairs can be  miniaturised and lost. That’s the reason as to why anticipat-  ing the future hair loss is most important factor while plan-  ning hair transplant procedure.   Hair transplant as a procedure is successful only when  hair loss is stabilised, as it will not stop further hair loss. We  as surgeons can only relocate and transfer few strong folli-  cles from donor area to recipient area without increasing any  new follicle per se. Many young patients who are frustrated  by taking medicines over a period of time will seek hair  transplant procedure as a remedy, which is an absolutely  wrong decision for the clinicians to encourage. It is impera-  tive on the part of the clinician to stabilise any ongoing hair  loss before embarking on the hair transplantation, with indi-  viduals below the age of 25 years being denied the scope of  the procedure.   Hair transplant surgery demands good planning, great  surgical skill and good aesthetic sense on the part of the cli-  nician, as hairs grow in specific direction and angulations for  the given area of the scalp, and grafts should be placed in a  way which should look natural and cover the scalp gaps thus  achieving good density.   Most of the patients would like to know if the results are  permanent with guaranteed results. Here, it’s the astute clini-  cian who should make all efforts to ensure that patient under-  stands the concept of the hair transplant and the future  consequences too, rather than simply promising the results.   The basic concept in hair transplant surgery is one of  camouflaging technique which makes them look better rather  than taking them back to their crowning glory days of their  past during their younger days.    and it’s a progressive process. Hair transplant will only help  him to maintain hairs which are aesthetically acceptable for  his age and few individuals may require future sessions too.   Routine blood test consisting of Complete blood count, gly-  caemic levels, prothrombin time and serology are done for  every case. In patients with any underlying medical condi-  tions, further investigations as deemed necessary for the case  are done and a medical fitness is obtained from the  physician.   All patients are advised to stop topical minoxidil at least a  week prior to transplant to avoid bleeding hampering the  progress of the case.   Photographs and consent for the procedure are obtained  as a part of standard operating procedure for hair  transplantation.   Consenting for the procedure should focus on detailed  information of the procedure with clarity given on the results  that can be obtained explaining the pros and cons of the proce-  dure, their complications and outcomes. Alternative sugges-  tions should also be given including no surgery, use of  camouflage techniques and patients being on only medicines.  Adequate time should be given to discuss and understand the  proposed procedures. Finally, the proposed treatment plan with  the fees proposed should be mentioned in the consent along  with written preoperative and post-operative instructions.   The treatment plan formulated needs to account for the  quantum of hair to be transplanted, the hairline design, the  areas of high priority on the scalp, patient commitment and  compliance.    FUT is also called strip method or stitch method. It’s a gold  standard method in hair transplant procedures till date though  it’s an old method [7]. The modern-day FUT is mainly har-  vesting a single strip, though earlier few doctors practised  with multiple blades to obtain multiple strips which are  obsolete now.   Strip method includes taking or harvesting a strip of the  skin layer from the donor area usually from the occipital area  of the head below the occipital protuberance and above the  nape of the neck in the so-called safe zone for harvesting.   Strip measurements are variable with 30 cm being the  maximum length and 1—2 cm width depending on skin laxity  of the patient. However, the length and width are variable  according to planning arrived at during the consultation with    the patient as per the indication of the case. At times we have  to limit strip width to 1 cm if the skin laxity is limited.  Usually a strip of 30 cm in length and 1.5 cm in width will  give around 2000-3000 grafts depending on the hair density  of the individual.   e We can harvest up to 4000 follicular units in a sin-  gle session.   Hair transplant outcomes will greatly depend on the donor  hair quality and quantity [8]. The important factors that the  clinician has to bear in mind are as follows:    1. The number of grafts that are present per square  centimetre  Few individuals have thick density being good or best  donors (Fig. 34.6a) while a few have sparse density being  poor donors (Fig. 34.6b) with the number of grafts per sq  cm varying between 25 and 65 grafts on an average in  healthy Indian adults. It further varies from person to per-  son and sometimes from area to area in the same indi-  vidual. Usually, occipital area has thick density whereas  parietal area has less density. Good observation of the  grafts in the donor area is most important for the surgeon  to achieve good results.   2. Number of follicles present per graft  This is highly variable with 2, 3 or 4 follicles being pres-  ent in Indian adults whereas a few have only one or two  follicles per graft. The presence of reducing follicles per  graft is a sign of the progressive nature of the blading  process.   3. Donor skin area  Few individuals have large donor area as their scalp size  is larger while a few individuals have donor bearing area  which is smaller (Fig. 34.7a, b). This entity will decide  the number of grafts that is available for harvesting.    Fig. 34.6 (a) Good/best donor area based on hair follicular density. (b) Poor donor area based on hair follicular density. (c) Donor area skin laxity  testing to ascertain the strip width planned for FUT    Fig. 34.7 (a) Large head with more surface area at donor zone. (b) Small head with lesser surface area at donor zone    4. Shaft diameter  Individuals with thick shaft diameter will have better den-  sity and the outcome of the results is enhanced.   5. Skin laxity (Fig. 34.6c)  In individuals with better skin laxity, we can harvest more  grafts by FUT method by going for wider strips in a sin-  gle session, whereas the same skin laxity may not have  any significance with the FUE method.  Patients who present with straight hair end up optically  having less density because light can pass through hair  strands and skin becomes visible especially if the hair is  black and is contrasting against a fair skin background.  Whereas presence of curly and course hair in an individ-  ual with dark complexion can give the illusion of thick  density.   Trimming is essential in the donor site to harvest the strip  and the team member in charge of the preparation can ensure  trimming the hair to 3 mm all over the scalp. Few surgeons  prefer the procedure without trimming so as to reduce the  downtime for the patient’s social acceptability. But trimming  will ensure better visibility and accessibility to the surgeon  while performing the suturing with attention to detail to  ensure minimal scarring along the strip harvest. Following  the trimming, the next step is to wash the scalp with betadine  solution. The clinician should ensure that preoperative pho-  tos, consent for the procedure, recording of baseline vitals of  the patient and his weight is recorded prior to the preparation  of the donor site.   The harvesting of the strip is done with the patient in  prone posture following the standards of care with an iv  line, monitoring of the vitals with a 3 parameter monitor,  and following a dose of prophylactic antibiotic under  aseptic conditions. Next, the donor area strip length and  width to be harvested are marked out based on the skin  laxity tests and depending on the individual’s follicular  density per square cm.   Once the marking is done, local anaesthesia is adminis-  tered to the donor area, usually preferring field block in that  area. Injecting the local anaesthetic in the lower border of the  strip would provide sufficient anaesthesia to the field above.   Hair transplant procedure is time taking and lasts around  6-8 h. Lidocaine usually is a very safe anaesthetic with a  duration of action lasting between 90 and 120 min and there-  fore we need to add a long-acting drug-like bupivacaine for  hair transplant procedure. Combination of the above would  work better for 8-10 h and the overall dosage should not  exceed the maximum permissible as per the weight of the   Lidocaine 2% 30 ml + bupivacaine 0.5% 4 ml + ns 60 ml.  The above combination gives 64 ml of local anaesthesia,  which is of lidocaine 1%.   Tumescence is widely used in hair transplant surgery to raise  neurovascular bundles away from the hair follicles which  will reduce the trauma to nerves and vessels during the  procedure. Another important role for the use of tumes-  cence is in reducing the bleeding during the procedure  since scalp bleeds more.   Tumescence solution consists of 500 ml ns + 1 ampule of  1:1000 epinephrine and this is injected into the strip area  following the local anaesthesia at least 15 min before the  strip harvesting.    34.9.1.4 Instruments for the Strip Procedure  Variscore blade (Fig. 34.8) is useful to have control on the  dimensions of the strip and it gives the option to adjust the  strip width by adding or reducing the metal spacer plates. Each  metal spacer plate comes with thickness of 2 mm and 1 mm  and, for example, if we need a strip with width of 1.3 cm, then  we need to add 6 plates of 2 mm and | plate of | mm. The  variscore blade has added advantage of depth control while  making incision and can accommodate two surgical blades.  Usually, for scalp, we can use number 15 surgical blades.  Prior to the incision marking, the strip dimensions are  done. Most of the surgeons make straight incision, which  may lead to scar. It’s always better to follow Langer lines of  the skin which ensures less scars with the strip incision look-  ing like a crescent shape with the end tapering off. Strips  which are as long as 30 cm (Fig. 34.9) in length run from  above one ear to the other ear. It’s always recommended to    place the incision at or just below the external occiput area as  the follicles here are considered permanent. It is indeed not  good to go too low below the external occiput as we may end  up in big blood vessels. After the initial indentation of the  incision is done with variscore blade, it is later followed up  by the use of BP blade number 15 and the incisions are made  very carefully to reach up to 3 mm beneath the follicular  depth with some amount of subcuticular fat around it, while  we ensure that we do not cut the galea. While making the  incisions, care is taken to prevent slicing of the follicles at  the skin margins and the flap is raised from one end to the  other using gentle yet deft strokes with the blade.   Good illumination and haemostasis can help to raise strip  with minimal damage to both the follicles and vessels in the  vicinity. Damage to the vessels is most common if proper  tumescence is not attained and can lead to bigger scar and  shock loss of hair in the donor area. Any adventure into the  galeal layer can lead to haematoma and chances of spreading  infections through emissary veins.   Haemostasis is achieved prior to closure by using  bipolar diathermy; the scalp wound is irrigated with nor-    mal saline and a double layer closure is performed with  vicryl 2.0 (TS 2404, 3/8 circle, cutting edge) for the  inside and a prolene 3.0 (nw800, 3/8 circle cutting edge)  for the outer skin (Fig. 34.11la, b). The strip that is har-  vested is preserved in cold saline on a petri dish  at 4 °C.   Trichophytic closure (Fig. 34.10) involves trimming of  the upper and lower edges of the skin which facilitates the  hair to emerge through the scar ensuring that we will give  aesthetically acceptable scar to the patient (Fig. 34.12b)  Wound closure done without the above clinical manoeu-  vre leads to poor scar (Fig. 34.12a), which is quite  obvious.   Post-operative care of the wound is important. Antiseptic  creams are optional if the donor site wound is washed with  clean water or ns on a daily basis. In our experience, suture  removal is recommended on 1 Ith post-operative day to avoid  wound gaping or wound dehiscence.    Fig. 34.12 (a) Poor scar resulting from normal wound closure (b—d) post operative scar following trichophytic closure    This will help us to get maximum grafts with less tension along the scar leading to a better scar. Most of the individuals  have thick density in the occipital area and lesser density in the parietal area and any misjudgement will lead to poor  wide scar in the parietal areas. Here, by using variable dimensions of the strip technique (Fig. 34.13), we can target for  more grafts with least possible scar. In this technique, the strip width is more in the occipital area than compared to the   Slivering is a process where the strip is sliced into small bits of  tissues with rows of hair follicles in them, through meticulous  deft handwork akin to the baker slicing the bread loaf into thin  slices. It is the first step of the separation of grafts from the  strip while avoiding any transection of the graft. Higher mag-  nifications should be used to perform this important step for  which a few clinics are using stereoscopic microscopes while  the others manage with normal 10x magnification. It should  be done simultaneously while the surgeon performs the wound  suturing to save the crucial graft holding time of around 6 h.   At the end of this step, we get slivers which are ready for  the separation process (Fig. 34.14). The separation process is  separating individual grafts from the sliver. For the separa-  tion process, we need more trained technicians as it is cum-  bersome exercise and needs great attention to detail to avoid  any form of trauma to the graft being obtained with an obvi-  ous fight against time.   For the separation process, we need to use 3x magnifica-  tion which can be done on a sterilised wooden spatula or an  acrylic illuminated sheet.   Wooden spatula would give us good resistance to cut the  grafts whereas acrylic sheets will be slippery. Advantage of  the acrylic sheet is we can illuminate from below, which is  easy for separating the grafts. The separation process is noth-    ing but getting rid of the excess fat around the grafts and  making the grafts slender in a pear shape or tear drop shape.  Care is to be taken to ensure that we do not denude the roots  and little fat is left behind for survival of the graft through  plasma imbibition. All skin has to be trimmed and removed  from the graft and finally these prepared grafts are preserved  in cold normal saline around 4—8 °C temperature.    While separating the grafts, we would get single, double,  triple follicular unit grafts, and care is exercised to maintain  the follicular unit (Figs. 34.15 and 34.17a), as it is natural to  ensure better survival. These are segregated further in different  bowls and are used up for implanting starting with single units  for the frontal hairline and progressing onto multiple follicular  units as we go posteriorly in a progressive manner.    In this technique, we extract the individual follicles one graft  at a time with the help of small punches. Also known as no  stitch and no cut method, it’s minimally invasive procedure    compared to the FUT. FUE gained popularity in recent years  because of its ease of doing and being less invasive with  minimal downtime for the patient. Initially, FUE was intro-  duced with manual punches which was more tedious and  time consuming limiting the number of grafts that could be  done in a session [9]. Current advances with motorised  punch have improved the pace and its effectiveness in har-  vesting more grafts. Though many different motors and  punches are available in the market, normal dental micromo-  tor with straight hand piece would suffice to perform FUE  (Fig. 34.16a, b).   Punches are made up of either titanium or stainless steel  with the diameter of the punch ranging from 0.6 to 1 mm,  with 0.9 mm being suitable for Indian scalp. The advent of  FUE has expended the scope of harvesting follicles from  other sites of the body wherein 0.6 or 0.7 mm punches are  useful for beard site and 0.8 or 0.9 mm punches have been  suitable for chest hair harvesting, respectively.    Fig. 34.16 (a, b) FUE instruments: micromotor, straight handpiece and punches    Punches are available as dull, sharp, serrated and oscillat-  ing type. Normal dull or sharp punched would be sufficient  to perform FUE. On an average one punch can be used to  harvest around 1000-1500 grafts.   Being a blind procedure, this is technique sensitive and is  associated with a steep learning curve requiring more con-  centration. It is performed under 3x magnification control-  ling the punching around the hair graft while maintaining  depth and angulation which is very vital to harvesting the  grafts. The punch should get down to epidermis and dermis  junction not going beyond 4 mm from the skin. Surgeon  should always analyse the angle of exit of the hair and be  parallel it prior to the punching. Acute angles of the grafts  would lead to difficulty in punching and lead to not only big-  ger punch holes but higher transaction rates. Most of the  Indian skin is favourable for FUE procedure because of  thicker skin types. The follicles obtained by FUE are com-  paratively slender and devoid of extra adventitious tissue in  comparison to the FUT follicles (Fig. 34.17b).   They can vary in size and shape from being thin sharp blade to  having a pointed chisel as in the case of sp90 which is one of the  popular blades for pre slit technique. Today, the surgeons have a  choice of customising the blade with commercially available  tools and can use a square or tapered blade as per their choice.   Standard 19 gauge hypodermic needle is preferred for mak-  ing the graft recipient sites while the same can be achieved  with solid core needles eliminating epidermal implantation.    34.9.2.3 Limitations of Follicular Unit Extraction  FUE has an important role to play in hair transplant because  it can reach the areas where strip cannot reach to harvest  grafts. When we plan second session, FUT may not be pos-  sible in unyielding skin types. In poor candidates where  donor areas of the scalp have poor hair quality, FUE can be  used to target beard and body hairs. FUE like any other  procedure is associated with a few disadvantages like com-  paratively more GTR (graft transection rate), especially in  curly hair types and in these few cases graft yield is abys-  mally low wherein the surgeon will have to convert the case  to strip technique. Follicular splay is another situation  where hair roots are placed apart which causes difficult  extraction. In case of scattered grafts too, the punch may  tend to damage more grafts while harvesting and would not  be an ideal situation to continue harvesting with high graft  transection.    34.9.2.4 Hairline (Fig. 34.18a, b)  The hairline design and location are the most critical factors  in the success of hair transplantation, for which one should  understand the concept of facial thirds. Till the age of third  decade of life, the anterior hairline at the midline is located  at a distance equal to the middle third height of the face from  the glabella, adding additional 1 cm in length to it with each  passing decade of life to take the hairline upwards and back-  wards to give a matured look to face considering the  progressive nature of hair loss. The frontotemporal apex is  the deepest point of the anterior hairline laterally as it merges  with the temporal hairline and is located along the lateral  canthus of the eye [10].   It is to be borne in mind that the hairline anteriorly is not  a straight line but an irregular one having peaks and troughs  making it look like a coastline with the front two rows made    Las ad Gane  @©Association of Oral and Maxillofacial Surgeons of India    up of single follicular units and gradually it progresses to  double and triple follicular units to give the density. The cen-  tral core or frontal tuft area gets the maximum density of  hairs implanted to enhance the strength and aesthetic value  of the hairline thus created.   by making slits in the skin with either 19 gauge hypodermic   which are of 1-1.1 mm in width. This step could be done    prior to implantation for all the grafts (pre-slit method) or  individually for each graft while simultaneously implanting  it (stick and place method).   Slits made with blades tend to give more natural looks  when compared to needle implantation (Table 34.1). As a  prerequisite to facilitate implantation, the site needs to be  trimmed short while the remaining hairs guide us in the  direction and angulation of the implantation. Proper  tumescence will allow us to expand scalp so that we can  place more grafts in the given area while also reducing  any damage to the neurovascular bundle and enhances  visibility.    The slits are performed in the area with proper direction  (converging forwards), depth (follicular length for the given  patient) and angulation (15° in the front —45° as we approach  the crown part of the scalp).   Once the slits are done, implantation is done by using  jeweller’s forceps (Fig. 34.21), which are pressure graded.  This is also called 2 forceps technique as one forcep is used  to locate the slit while the other one is used to implant the  graft into the slit. The grafts are to be held above the bulb or  beside it where the dermal fat is held.   Few surgeons use implanters (Fig. 34.22b) which can hold  the graft in it and all you have to do is to eject them into the  site at the desired direction and angulation. Technicians will  preload the graft into the implanter. Implanter can be used    with pre slits or without pre slits made in the scalp. However,  implanters tend to create a circular slit which may lead to  pitting kind of scars at the base of the graft after growth.  They need extra hands for the procedure and come at an extra  cost too.    This is a combination of FUT and FUE in a single session.   Combi technique is recommended when we need more  grafts as in anything over and above 3500 follicles in a  single session. In this technique, the strip is first harvested    Fig. 34.22 (a) Immediate view of a case post implantation. (b) Implanters used for implantation    and then the FUE is performed above and below the strips  in the same sitting before implanting. Advantages of this  procedure are that the surgeon can reduce the strip length  and still can obtain more grafts thereby reducing the strip  length and the resulting scar. However, it requires an  experienced surgeon and well-trained team to execute the  procedure.    Immediately after the procedure, the heaviness, numbness or  tightness may be there for a few hours. There is also some  swelling on the forehead and temple area due to the tumes-  cence and surgical insult and the resulting swelling is normal.  Patients are allowed to sleep on the back or on the sides but are  not allowed to sleep on their tummy as otherwise the swelling  tends to gravitate onto face and eyes. Patients should be asked  to massage the forehead from the middle to the sides for 5 min  every hour for first few days. Rarely some patients may feel  momentary dizziness especially while standing up from the  lying down position on the procedure table.   There is some oozing of blood-stained fluid from grafted  site as well as in donor area (both in case of strip or FUE).  Bending forward of the neck can stretch the stitches and can  initiate some more oozing from the stitches therefore keep-  ing the chin up is recommended.   Patients are restricted to perform any contact sports/gym-  ming for a period of 12 days and should avoid swimming for up  to 3 weeks. They should also not get to field work under the sun  for first 3 weeks. Patients who ride a bike are allowed to wear a  helmet after a period of 4 weeks. Topical minoxidil can be  restarted in the transplanted site after a waiting period of about  15 days post-operatively. Patients are also forbidden from riding  a bike or driving in an open vehicle for up to 2 weeks.   After the procedure, antibiotics and analgesics are pro-  vided for 5 days. The donor and recipient sites may or may  not be bandaged. If bandaging is preferred, a non-adhering  betadine pad is placed over the operative sites with several  layers of flattened gauze sponges over them to hold the beta-  dine pad in place as the scalp is wrapped with clean bandage  using to two to three 4-inch gauze rolls. Crepe bandage can    be used over it. The dressing is removed the following morn-  ing, and the scalp and each graft are clean meticulously by  gently dabbing with a cotton swab with normal saline.  Patients are advised to sprinkle or spray normal saline over  the grafts every 3-4 h for 8-10 days. Suture removal is per-  formed on 11th day and is not applicable for FUE. Initially  for 10 days the grafted area should be washed without rub-  bing the grafts. Whereas after the above period, grafted area  can be washed and patients can rub the grafts. Most of the  grafts will be shed by 12—20 days which is a common phe-  nomenon, one need not to worry about it falling off.   Immediate after a hair transplant, there will be mild blood  excretion and oozing.   Ist day scabs (nothing but dried blood) will form and con-  tinue forming for the next few days.   After 4 to 10 days you will notice itching. This is normal,  but do not scratch or pick on the transplanted areas.   After 10 days your scalp will be cleared of all scabs.   Pt must be aware that a lag phage exists before hair growth  is initiated. After approximately 4 months, the telogen phase  to the implanted grafts ends and anagen begins. Complete  growth can be seen only after 8 months and hair continue to  grow until 12-14 months.    Able professionals should manage any adverse outcomes by  minimising the damage and help achieve the desired out-  comes with low morbidity. Fortunately, today the follicular  unit hair transplantation is a safe procedure with low rates of  complication when performed with care [11].   Overexpectations of the patients are the major cause of  complications and arise due to hasty or incomplete consul-  tation and is better addressed with more than one consulta-  tion to assimilate the requisite information with the help of  informative brochures, websites and discussions with the  clinician to arrive at realistic outcomes especially in the  younger patients who happen to be unclear and lack matu-  rity for comprehending the results; in such cases, it’s better  to keep them on medical line of treatment till they become  practical in accepting the results. Any individual with body  dysmorphic disorder and Norwood vii patients where you    would not make much difference would count as poor  patient selection by the clinician. In case of ongoing hair  loss, the clinicians should not be tempted to promise full  coverage or high density influenced by the advent of cur-  rent medicines as the patients may change their minds and  stop the intake of medicines over a long period of time,  eventually resulting in inappropriate placement pattern and  lack of donor site for harvesting. Clinicians should not be  further influenced by the patients’ demand for low unaes-  thetic hairline, or be drawn into performing mega sessions  arising out of patients’ demand and be careful in choosing  the donor material in the middle of the back and sides of the  permanent fringe avoiding any slanted scars or scars visible  in scanty donor hair bearing areas.   1. Pain:  Patients who are counselled appropriately and are pro-  vided with a relaxing ambience generally experience  minimal discomfort. In-depth local anaesthesia achieved  through precise nerve blocks and ring blocks adminis-  tered with a long-acting drug-like sensorcaine and taking  help of vibrating devices while injecting the solution  slowly will go a long way in enhancing the comfort lev-  els. Anxiolytics should be prescribed by the clinicians to  patients who are apprehensive about the procedure.   2. Bleeding and popping:  Optimising the health of the patient prior to the surgery  results in blood pressures being within normal limits.  Adequate tumescence consisting of saline and epineph-  rine has to be injected below the dermis to allow the sur-  gical field to be lifted away from the bleed vessels and  then the clinician has started the procedure after 15 min  will have minimal bleeding. Too much of tumescent in  the recipient site can be a cause of popping, though clini-  cian cannot eliminate popping as pre slit technique can  minimise the issue.   3. Bad hair direction:  Clinicians should plan appropriately to maintain the direc-  tion and exit angle of the hair that mimics the natural growth.  Keeping the grafts with a few millimetres of hair will allow  the clinician to ascertain the angle during implantation.   4. Hiccups:  Due to the irritation of the aberrant branch of the vagus  nerve, patients can have hiccups through the procedure.   5. Poor graft quality:  A good team leader will constantly supervise to ensure  proper handling of the follicles, which will minimise  trauma to the follicle resulting from transaction, manipu-  lation, desiccation, oxygen starvation and crushing of the  graft [12].    1. Donor site effluvium:  Hair in the growth phase can fall rapidly post transplan-  tation due to temporary lack of oxygen during surgery  resulting in loss of hair variably along to suture line  when significant blood vessels are cut. Any such hair  loss will be noticeable around the third week post-  operatively and leads to embarrassment to the surgeon.  If the donor area can be raised above the blood vessels  with good volume of tumescence, the above complica-  tion is rarely encountered.   2. Infection:  This is a very rare complication seen today given the  standard asepsis precautions followed and is rarely  encountered where the patients are not given adequate  post-operative instructions especially in cases of tight  donor area closure and in patients with compromised  immunity.   3. Dehiscence:  A poor surgical technique associated with bad suturing,  harvesting wide strips, performing tight closures or  resulting infections and necrosis can lead to dehiscence.    use of tumescence which will lift the hair follicles above  the neurovascular bundles. ©Association of Oral and Maxillofacial Surgeons of India    ing the basic principles of surgery with accurate approx-  imation, closure without tension, by using double  layered closure, trichophytic technique and avoiding  resolvable suture for closing the skin. Donor scars also  occur due to improper donor assessment prior to the sur-  gery. Skin laxity test will help us to evaluate the skin  laxity so that we can limit the strip width. At times we  may need to consider variable width dimension to reduce  the tension in the wound, usually where occipital area 8  skin laxity is more and parietal area skin laxity is less. So   we can consider more width at occipital area and less  width at parietal area. If skin has less laxity, we can con-  sider FUE.   Any hypertrophic scar can be managed with steroid or  injection and later implanting hairs with FUE.   6. Forehead swelling and ecchymosis: 9  Based on the laxity of the skin in the frontal area and the  trauma induced by the slit making process, swelling  occurring at 3-4 days post hair transplantation can be  mitigated by including some steroids in the la solution,  applying pressure bandage and some digital massage  across the forehead.   This is similar to the donor site effluvium which  results in the anagen hairs going into telogen phase  and falling out around the second or third post-opera-  tive week and regrowing with the grafts. Preoperative  use of minoxidil solution tried 1 month prior to the  procedure is recommended to prevent the above  complication.   . Cysts, pustules, pimples and folliculitis: (Fig. 34.25)  The above sequelae following hair transplantation can  be avoided by preventing deep implantation of grafts,  transacting hair during site creation and piggybacking of  one follicle up on another. Most of them do settle down  with time; however, acne like therapy can be offered to  resolve the lesions faster.   It’s very important to avoid the above complication in the  frontal hairline which could otherwise be unacceptable  and are easily preventable by avoiding deep placement of  the grafts as in the case of pitting and too superficial  placement of the grafts as in the case of tenting.    10. Poor growth:  This can be attributed to poor handling of the grafts  resulting in physical and biological trauma to the grafts  associated with dehydration of the follicle, crushing of  the follicle during implantation, thermal insult and pro-  longed holding time outside the body.    The incidence of complications may be reduced by avoid-  ing mistakes by the team in general (Box 34.5) and those  related to the technique, specifically graft survival (Box 34.6).    e Too much cross talk between team members annoy-  ing the patient.    Futuristic developments in the field of hair transplant need to  focus on the current lacunae in the procedure and revolves  around the availability of limited donor supply and the dura-  tion of the procedure.   Low-level laser light therapy has been approved by FDA  as a device to stimulate the hair growth in the 650-800 nm  spectrum. Home-use scalp brush or helmets with laser tech-  nology are available which use the pain-free technology to  stimulate epidermal stem cells in the hair follicle to move the  follicles into anagen phase.    Automation of the FUE process with the use of robotics  has shown to reduce the follicular transaction rates and  improve the harvest speed, resolving the issue of skills pos-  sessed by practitioners. Artas and neo-graft are devices  which have glamorised the field by involving robotic tech-  nology, but the running expenses and need to create sites and  manually implant follicles need to be solved in the coming  days.   If hair can be cultured from the scalp biopsy, then the  patient would not need to donate hair by going through a  painful procedure, by cloning hair we can create unlimited  supply of follicles and avoid ration of hair. Current state-of-  the-art research promises that the technology would get  transferred from bench side to the bedside in a few years  from now.    A maxillofacial surgeon makes a good hair transplant sur-  geon as they are well trained in surgical anatomy of the head  and neck with a detailed knowledge of flap design and  through in-depth working knowledge of the local anaesthesia  management. They have a great aesthetic sense with artistic  hands and are well versed with cephalometric analysis which  comes handy in judging facial proportions and _ hairline  placements, further most of them are very well adapted to  handling the rotary handpiece from their formative training.  Maxillofacial surgeons are well trained exclusively in head  and neck surgery for 3 years and are competent at managing  wounds and infections, thus justifying their qualifications to  perform hair transplantation alongside plastic surgeons and  dermatologists.    Surgeons who deal with aesthetic surgeries on the face need  to have a good range of skills to deal with all aspects of  beauty which are defined by the individual elements. The  most important of them all being framing of the face like a  photo frame with hair transplantation which will allow us to  focus our vision on the finer elements of the facial beauty be  it the nose, lips, eyes, teeth, jawline or a good smile. If sur-  geons follow the principles of hair transplantation surgery,  they will create patients with high degree of satisfaction  using the micrografts of FUE or FUT procedure. This sophis-  ticated form of art will bring a sense of gratification to oral  and maxillofacial surgeons by embracing it as a tool along  with all other tools at his disposal.   Treatment: 4000 follicular units transplantation done  through Combi technique involving both FUT and FUE in  the same session.    . Bernstein R, Rassman WR, Seager D, et al. Standardizing the    classification and description of follicular unit transplantation and  mini-micrografting techniques. Dermatol Surg. 1998;24:957-63.    . Price VH. Treatment of hair loss. N Engl J Med. 1999;341:964—-73.  . Unger W, Shapiro R. Hair transplantation. New York: Marcel    Bernstein RM, Rassman WR. Follicular transplantation: patient  evaluation and surgical planning. Dermatol Surg. 1997;23:771-84.  Bernstein RM, Rassman WR. The logic of follicular unit transplan-  tation. Dermatol Surg. 1999;17:277-95.   Rassman WR, Bernstein RM. Follicular unit extraction—minimally  invasive surgery for hair transplantation. Dermatol Surg. 2002;28:720-8.  Shapiro R. Principles and techniques used to create a natural hair-  line in surgical hair restoration. Facial Plast Surg Clin North Am.  2004;12:201-17.   Cooley JE. Complications of hair transplantation. In: Unger WP,  Shapiro R, editors. Hair transplantation. 4th ed. New York: Marcel  Dekker; 2004. p. 568-73.   Bernstein RM, Rassman WR, Rashid N, Shiell RC. The art of repair  in surgical hair restoration. Part 1: basic repair strategies. Dermatol  Surg. 2002;28:738-94.    Open Access This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.  org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropri-  ate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.   The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in  a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.   The human ear is a vital and distinctive feature of the face,  and therefore, its deformity confers a significant impact on  self-esteem and mental development in affected patients.  Microtia is the commonest congenital ear malformation. The  management of ear malformations can be challenging,  because of its complex 3D structure. To achieve proper  reconstructive results, it is first essential to understand the  basic anatomy and architecture of the ear [1]. Materials used  for reconstruction of the ear include autogenous cartilage,  alloplasts like silicone, Medpor, and osseointegrated materi-  als. Surgical reconstruction of the ear with autogenous grafts  is a unique marriage of science and art [2]. Good results  depend not only on surgical skill but also on conforming to  the basics of plastic surgical principles and tissue transfer.  The gold standard for external ear reconstruction even today  is the use of autogenous cartilage frameworks.   The incidence of microtia is around 1 in 10,000 live births.  It appears to be more frequent at higher altitudes, especially  above 2000 m, due to the low oxygen levels. The condition  is 2.5 times more common in boys than in girls and more  commonly affects the right ear. Unilateral cases are four  times as common as bilateral ones. Aural atresia is found  with microtia in 75% of cases. Microtia usually occurs if  there in an abnormality in the embryologic development of  the six auricular hillocks. These develop at 4-12 weeks of    Electronic Supplementary Material The online version of this chap-  ter (https://doi.org/10.1007/978-98 1-15-1346-6_35) contains supple-  mentary material, which is available to authorized users.    P. Ladani   Oral and Maxillofacial Surgery, Swiss Cleft and Craniofacial  Centre, BSES MG Hospital,    © The Association of Oral and Maxillofacial Surgeons of India 2021    gestation. Microtia may be associated with other birth  defects. The exact cause behind the abnormal embryologic  development remains unknown. However, certain terato-  gens like isotretinoin and thalidomide have also been impli-  cated in this [3].   Microtia may occur in association with other malforma-  tions, including facial nerve weakness, cardiac defects, uro-  genital defects, hemifacial macrosomia, and spine defects. It  has also been associated with syndromes like Goldenhar syn-  drome and Treacher-Collins syndrome [4].    It is crucial to understand the external auricular anatomy and  architecture before proceeding with reconstruction  (Fig. 35.1a). The ear has certain definite structural elements.  The overall outline of the ear is oval shaped and is slightly  flattened posteroinferiorly. A distinct line can be made out  that defines the helical rim, arising from its root and ending  at the crus helicis. Another line forms the concha, which con-  sists of the tragus and antitragus. The fossa triangularis is the  final defining structure that defines the ear (Fig. 35.1b). A  complete understanding of these structures allows the micro-  tia surgeon to use these basic components to reconstruct the  complex three-dimensional structure.   When viewed in the horizontal plane, the ear is divided  into three parts. The superior portion starts at the top of the  helical rim and ends at the helical root at the superior border  of the concha cymba. The midportion starts at the upper bor-  der of the concha cymba and ends at the upper aspect of the  antitragus. The lowest portion extends from the tip of the lob-  ule to the superior border of the antitragus. The length of the  ear is defined as the distance between the highest point (supra-  aurale) and the lowest point (subaurale). This may vary  between patients in accordance with the differences in the  shape of the patient’s face and their lobule characteristics. For  instance, the ear lengths vary from 55 mm to 65 mm, with a    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1-15-1346-6_35    mean of 62.4 mm in males and a mean of 58.4 mm in females.  The width is approximately 55% of the ear length and is  around 35.5 mm in males and 33.4 mm in females. The pro-  trusion of the ear, also called the auriculocephalic angle,  ranges from 15° to 20°. This is the angle between the mastoid  skin and the posterior surface of the auricle. Again, this may  show variation between patients. However, this angle should  remain the same in both the normal and the reconstructed ears  [3]. The angle between the vertical axis of the face and the  longitudinal axis of the ear is referred to as the ear inclination.  It must be measured with the patient oriented to the Frankfort    horizontal position. This is around 24° with the face, but is  32° in relation to the nasal dorsum (Fig. 35.2).    There are four grades of microtia, depending on the severity.  These are as follows:    Grade |: The ear has anatomically normal characteristics,  but may be slightly smaller than normal. An external  auditory canal is usually present, but may demonstrate  atresia.   Grade 2: The size of the ear is than in grade 1, and it may be  less developed. Although a part of the helix may be  formed, the triangular fossa, scaphae, and antihelix are  under-developed. Atresia of the external auditory canal  may or may not be an associated feature.   Grade 3 or classic: This is the commonest grade seen and  usually consists of a vertical remnant of skin. There is a  superior component that contains the malformed carti-  lage, and an inferior component that forms the displaced  earlobe. This grade is almost always associated with  atresia.   Grade 4 or anotia: The outer ear structure is completely  absent, and atresia is always present.    There is another simplified classification, in which micro-  tia is divided into the lobular type (ear remnant and lobule    are present) or conchal type (presence of concha, external  canal, and tragus with lobule) (Fig. 35.3).    The management of a child with microtia should ideally be  discussed with parents shortly after birth, to reduce parenteral  stress and offer them reassurance. The audiologic testing  should be performed before discharge. In cases of unilateral  microtia, treatment is not urgent because the other side will  have normal hearing. Treatment can be thoughtfully planned  after consulting with relevant specialists. However, in bilat-  eral cases, brainstem auditory-evoked response testing must  be performed as soon as possible so that the child can be fitted  with a bone-conduction headband. The microtia surgeon can  discuss about all the possible option with the family, includ-  ing observation, autologous costal cartilage, alloplasts, and  prosthetics. Each method of management has a different tim-  ing, and therefore, all optins must be discussed at an early  stage. In addition, the microtia surgeon must also coordinate  ear reconstruction with auditory management, so that the tim-  ing of the hearing correction may be optimized [4].    Timing of repair is governed by both physical growth and  psychological consideration. The ears reach much of their  mature size by age 7. Generally, by the age of 6, cartilage is  sufficiently developed to provide an optimal primary frame-  work. However, the older the child, the more cartilage is  available for reconstruction. On the other hand, waiting for  cartilage growth must be weighed against the psychological    and social effects of the missing ear on the child. Studies  show that psychological effects usually manifest only around  the age of 7-10. However, by age 6, most children are aware  of the problem and want to get it corrected [3]. The timing  can also depend on the method of reconstruction chosen. The  Brent method, which requires less cartilage, may be per-  formed as early as 6—7 years of age. On the other hand, the  Nagata method can be done only after 10 years of age, when  the chest measures at least 60 cm at the xiphisternum. This is  because it needs larger amounts of cartilage [1].    Tanzer et al. first established the technique for total auricular  reconstruction. The technique was modified by Brent, who  utilized more defined surgical techniques such as fabrication  of the framework and reconstruction of the tragus using com-  posite chondrocutaneous grafts. These techniques were three  stages and four stages, respectively. Nagata and Park out-  lined techniques that involved just one or two stages for ear  reconstruction [5]. Allolastic implants were tried since the  1960s. Initially, silicone implants were used, but these were  associated with complications such as implant failure fol-  lowing minor trauma or abrasions. In 1993, Wellisz reintro-  duced the prefabricated alloplastic implant for microtia  reconstruction. This was constructed from PHDPE [6].    The Microtia surgeon should begin with proper planning and  achievable goals for successful auricular reconstruction. It is  important to discuss the details of surgical procedure and    limitation of surgical repair with the family during preopera-  tive consultation. The surgeon must prepare the family for  multiple stages, long preoperative and postoperative care,  and complications. The reconstructed ear will possess some  deficits as compared to the normal ear and will be less flexi-  ble and elastic. The reconstructed ear can also be prone to  complications, including hematoma, poor healing, infection,  or skin breakdown. These complications can compromise  the definition and contour of the reconstructed ear [3].   If the patient has coexisting anomalies, such as clefts,  early surgery must be done first to correct these. For  instance, in cases of Treacher Collins syndrome and other  first and second branchial arch defects (craniofacial micro-  somia, Goldenhar’s syndrome, etc.), the bone reconstruc-  tion must be achieved first, with scars peripheral to the  proposed ear [7].   The precise positioning and dimensions of the recon-  structed framework will define the end result of the surgery.  The reconstruction must be symmetrical to the contralateral  ear in the unilateral case. In bilateral cases, the parent’s ear is  used as a reference. Visual examination may not be reliable,  and it is essential to make exact measurements, after prop-  erly positioning the patient. For an ideal position, the supe-  rior extent of the ear must be placed parallel to the Frankfort’s  horizontal plane, at the level of the lateral brow (Fig. 35.4).  The root of the helix may be positioned at the level of the  subnasale, approximately one ear-length behind the lateral  brow. Measurements must be taken carefully, particularly  from the lower one-third of the face, in cases of facial asym-  metry (seen in about 88% of patients with microtia). The  asymmetries can range from mild differences in gonial posi-    tion to full-blown hemifacial macrosomia and can lead to  inaccuracies in measurement [3].   The final outcome also depends on the skin quality  around the ear area. If the skin is scarred, natural expansion  cannot take place, and the final ear may have a poor defini-  tion. In such cases, supplemental tissue in the form of flaps  (e.g., temporoparietal fascia flap) may be considered to aug-  ment the supple skin envelope. In general, skin elasticity  varies for each individual, and this can influence the final  definition of the ear [8]. In cases of tight skin, a lower-pro-  file 3D framework (1 mm) may be created, to avoid strain on  the skin.    The surgeon must obtain enough training in plastic and  reconstructive surgery, including skills such as gentle flap  dissection, delicate wound closures, and skin grafting, to  achieve optimal outcomes. In addition, surgeons must be  familiar with precise carving that is required for forming the  3D framework for the ear. Potato, carrot, or pumpkin can be  used to learn and perfect the art of sculpting a framework  [8]. Silicone dental impression material provides a conve-  nient replica of costal cartilage, as it has the same consis-  tency and texture. An exact replica of the rib cartilage and a  precise template of the ear will allow the simulation to  mimic the clinical situation. Creating the framework can be  done using wood carving instruments. These techniques aid  the novice surgeon in improving their results during the  actual surgery [9].    Preoperative photographs should be obtained, and measure-  ments of the normal ear must be obtained when the patient is  awake. The surgical template is prepared from radiograph  film using normal ear as a guide. In the beginning, an outline  of the helical rim, lobule, antitragus, tragus, and conchal  bowl is created from the opposing ear as the first template  [3]. This template needs to be reversed to plan the ipsilateral  ear. Another mirror image template is created based on the  first one, which is smaller in dimension. This would allow  for the extra thickness following insertion of cartilage under  the skin (Fig. 35.5). The inferior pole on the framework is  created much smaller in size, to accommodate the transposi-  tion of the earlobe. If the patient does not have usable earlobe  tissue, this can be carved into the lower end of the frame-  work. A second template is created, this time minus the heli-  cal rim. This template is used as a guide for creating the base  of the framework from the sixth and seventh ribs, after which    the rim of the helix can be added. The templates must be  chemically sterilized prior to intraoperative use. A third tem-  plate, made along with the first, has markings at the lateral  canthus of the eye and commissure of the mouth. This allows  ideal framework positioning and orientation. The distances  marked on the template must be verified by measuring  the distance between the lateral canthus and the root of the  helix [3].    For harvesting the rib cartilage, an incision, 4-5 cm long, is  placed obliquely on the ipsilateral side, at the level of the  synchondrosis of the sixth and seventh ribs [10]. The inci-  sion is carried down through the muscle, to expose the costal  cartilages. It is safer to harvest the cartilage without peri-  chondrium because leaving the perichondrium behind offers  one more layer of protection to pleura. The perichondrium  also allows for the regeneration of the cartilage/bone matrix.  Removing perichondrium can not only offer less protection  but also lead to significant depressive chest deformities [8].  After harvesting is complete, intercostal nerve blocks may be  administered. Closure of the muscle and deep fascial layers  is done, and a large piece of cartilage may be banked in a  subcutaneous pocket for the second stage [10]. Smaller car-  tilage pieces may be diced and placed inside the sutured peri-  chondrial pocket, where it can aid in cartilage regeneration  (Fig. 35.6).    The supporting framework is a living sculpture that serves  as the foundation for the repair. Rather than carving the  framework to exactly mimic auricular cartilage, the sur-  geon must make allowances for the abnormal skin coverage  that is present. These limitations include skin-volume  shortage and greater skin thickness, both of which produce  excess skin tension. To prevent the flattening of the ear’s  rim that this tension might cause, one must carve a some-  what thicker and more substantial helix. This exaggeration  of the cartilaginous framework will compensate for the  thickness of the overlying skin. The 3D framework must be  at least 9.5-10.0 mm high in the case of primary recon-  struction and further augmented by 1.0—2.0 mm for second-  ary reconstruction [8].    Fig. 35.6 (a) 3D CT scan of Rib cage. (b) Incision for cartilage harvest. (c) Exposure of rib cartilage. (d) Template used to harvest cartilage. (e)    The cartilaginous framework is constructed from the syn-  chondrosis of the sixth and seventh ribs (Fig. 35.7b, c, d).  Cartilage wedges from these ribs are used to create the heli-  cal sulcus and the triangular fossa. The helix itself is formed  from the eighth rib because it is longer. If additional length is  required, the ninth rib can also be harvested (Fig. 35.7e) [10].  While carving the helix, it must be ensured that superior por-  tion is higher than the inferior portion. The part of the helix  that will be continuous with the lobule must be trimmed at  the lower end, until it is long enough to receive the lobule  attachment. The constructed helix is then affixed to the basal  cartilage. On doing this, an outward inclination of 10—15° is  maintained, at the middle one-third of the ear. The entire  length of the lower part of the basal cartilage, at the outer  end, is trimmed [5]. The floating rib cartilage that is used to  create the helix must be thinned on its outer convex surface.  This causes the cartilage to warp in a favorable direction and  creates an acute angle that resembles the helix. This cartilage  is then fastened to the body of the framework with 5-0    Stainless steel suture. The thickest parts of the remaining  segments of cartilage are used to create the rest of the auricle,  namely, the antihelix and antitragus-tragus complex, which  surround the conchal bowl (Fig. 35.7f). The highest point of  the antihelix is the middle, and this slowly tapers down to the  helix. The superior and inferior crura are created, at the slope  toward the lowest portion of the base frame. Enough space  must be secured between the upper helix and superior and  inferior crura, in order to accommodate the skin envelope.  Otherwise, an effect of continuity between 2 crura and helix  is created, which is undesirable [8]. The components of the  framework are then assembled and secured together using  5-0 stainless steel wires. To achieve a snug fit, a small inci-  sion is placed in the cartilage and the wire is pulled gently  toward the incision without burying it [10]. The position of  the antihelix within the antitragus must be high, and trim-  ming must be done at a lower level toward the superior and  the inferior crura. In order to augment the antihelix, cartilage  may be added in a vertical manner near the conchal area.    Fig. 35.7 (a) Armamentarium for carving, (b—d) preparation of base of the cartilaginous framework from the synchondrosis of the sixth and  seventh ribs, (e) helix prepared from eighth rib cartilage, (f) antihelix and tragus, and (g) Final framework    This gives an effect of deepening of the concha. The antihe-  lix is also trimmed in the region of the scaphoid fossa, so that  it develops a slight inclination that resembles the natural con-  volution. Finally, the surfaces of the entire framework must  be tapered smoothly tapered, and block-like corners must be  removed, to ensure that the covering skin fits on smoothly  (Fig. 35.7g). Throughout the process, isotonic saline solution  is used to irrigate the cartilaginous framework. This helps  preserve chondrocytes. The use of rotary and power tools  must be avoided to prevent chondrocyte damage [7].    A pocket must be created within the skin in a meticulous  fashion. This will provide proper vascular covering to receive  the framework. As per the level of the lobular remnant, the  level of the incision line for rotating the lobule may be deter-  mined. A small part of the lobular remnant is transposed pos-  teriorly and separated from the microtic remnant. Then, the  lobule is dissected and rotated to create a pocket that will  accommodate the caudal end of the cartilage framework.  This causes the lobule to be brought down and results in a  smooth interface between the lobule and the framework.  Creation of the skin pocket preserves the subdermal vascular  plexus. The amount of dissection (at least 2 cm beyond the  outline) must be wide enough to allow proper draping of the    skin flaps over the framework with minimal tension. Any  cartilage, if present in the vestigial remnant, is removed.  Meticulous hemostasis must be achieved [5]. An incision is  placed at the posteroinferior border of the vestigial remnant,  and the cartilaginous framework is placed in the subcutane-  ous pocket. The tail end of the framework is inserted into the  lobule first, followed by suturing of the outer incision. In  order to let the skin adhere to the framework, two polyethyl-  ene drains with multiple perforators must be inserted beneath  the framework. These are secured to the skin using 5/0 nylon  sutures. A syringe (50-cc) may be connected to the drain.  After final suturing of the subcutaneous pocket, the skin flap  is approximated, and the piston of the syringe may be fixed  in activated position using two wooden tongue depressors  (Fig. 35.8) [5]. If skin blanching is noticed at this stage, the  pocket must either be enlarged or the framework must be  inserted at a lower position. The use of pressure dressings  must be avoided as these can compromise the vascular sup-  ply. The entire reconstructed ear must be layered in petrola-  tum gauze, which must be placed loosely and left in place for  3 days [3]. The syringe with the activated piston may be  changed frequently in the postoperative perio, ensuring that  proper tension is maintained. The drains may be removed on  the fourth or fifth postoperative, provided that the volume of  fluid drained is less than 1-cc. Petrolatum gauze may be left  in place until suture removal, on the sixth postoperative day    Fig. 35.8 (a) Before  activation of suction and (b)  after activation of suction    The second stage of surgery involves elevating the auricle  from the head, which creates the auriculocephalic angle.  This procedure should ideally be performed 6-9 months fol-  lowing the first stage. In the conventional method, the inci-  sion lies several millimeters away from the margin, and  reconstructed ear is gently lifted from the base. Care must be  taken to preserve connective tissue on the undersurface of  the ear, as well as on the bony floor. The posterior part of the  auricle and the skin defect overlying the mastoid are grafted  with skin. Since the ear lacks skeletal support, it contacts the  mastoid skin and is not elevated. This creates a narrow space,  which may be difficult for the patient to clean [8].   In the Nagata technique, the second stage is more com-  plex than the conventional one. This involves the following  steps: (1) separation of the auricle from the mastoid, (2) The  banked subcutaneous rib cartilage or an alloplast is used to  create a wedge-shaped block, which is placed underneath the  auricle, (3) A temporoparietal fascia (TPF) flap is then har-  vested to cover the posterior part of the auricle, and (4) A  split skin graft harvested from the scalp to cover the fascial  flap. Scalp skin is preferred as it has better color match as  compared to groin skin (Figs. 35.9 and 35.10) [8].    The two commonest complications at this stage are pneu-  mothorax and atelectasis. If detected intraoperatively, pneu-    mothorax can be easily treated and may not require chest  tube placement. Positive pressure ventilation is used after  irrigating the wound to see if there is any leak. If there is no  leak, the wound is closed in layers. If a leak is seen, it indi-  cates the presence of pneumothorax. In this case, a red rub-  ber catheter is inserted into the pleural opening to which a  syringe is attached to this to evacuate residual air. Following  this, the chest may be closed and an intraoperative chest  radiograph is asked for to rule out residual pneumothorax. If  this is absent, the wound may be closed, the catheter may be  removed and follow-up may be done with serial films [3].  Atelectasis is best prevented by frank preoperative prepara-  tion of the patient and vigorous postoperative respiratory  therapy.    The first 10 postoperative days are critical to check for  any skin flap necrosis. It is essential to achieve a balance  between the thickness of the skin flap and the size of the  pocket with the contouring of the cartilage framework. To  prevent skin necrosis, it is advisable to minimize or com-  pletely avoid the use of epinephrine in the flap. The status of  vascular supply can be tested by placing the framework in  the pocket, activating the suction drain, and observing any  for blanching along the rim of the helix. If blanching is pres-  ent (indicating vascular compromise), the size of the pocket  may be enlarged until blanching disappears. If needed, the  skin supply may be increased by placing a tissue expander 2  months prior to insertion of the framework and skin adhesion  [1]. If skin necrosis is observed, it must be attended to imme-  diately, as it can cause infection of the underlying cartilage    Fig. 35.9 Ear reconstruction  in hemifacial microsomia  associated with microtia. (a)  Preop and (b) Postop    Fig. 35.10 Ear  reconstruction after traumatic  amputation of upper half of  ear. (a) Preop and (a) Post op    and framework resorption. The damage can be minimized by  covering with a local skin flap or fascial flap (Fig. 35.11).   This is uncommon in the autologous reconstruction. If it  occurs, along with appropriate systemic antibiotics, vigorous  irrigation of the surgical site must be done.    If there is either ischemia or infection, there are chances  that the cartilaginous framework can get resorbed or deformed.    This can also occur if the skin envelope is too tight, especially  at the hairline border. To avoid this, dissection of the skin  pocket around the hairline must be done carefully. Any tight  fibrous band that exists along the hairline must be released.    If any wires extrude from the framework, they can easily  be removed at the outpatient facility. It is necessary that the  wire must be removed as soon as extrusion is noticed, and  the patient/family must be educated accordingly. Otherwise,  there are chances that the exposed wires can cause resorption  of cartilage around the wire.    Fig. 35.11 (a) Necrosis of skin at near suture line, (b) debridement and marking for local flap, and (c) flap in situ    The material used for creating framework has been a subject  of debate and research. Autologous costal cartilage is still the  most preferred material in microtia repair. However, some  surgeons consider using alloplasts because of the following  advantages.   . The structural limitations associated with the use of  autologous rib may be avoided    The ideal alloplast for auricular reconstruction should  have the following features: cost-effectiveness, ability to be  implanted safely, ability to resist infection, and capability to  undergo customization to resemble the contralateral normal  ear. To date, more than 40 different materials have been used  for creating the auricular framework. These include ivory,    nylon, wire mesh, and silicone. Silicone was thought to show  good results since it could mimic the flexibility and form of  the native ear cartilage. However, it had a high rejection rate,  especially when placed under thin skin flaps. pHDPE (Fig.  35.12) is a modestly flexible, robust enough to withstand  microtrauma, and easily shapable and allows soft tissue  ingrowth. This permits it to be protected against extrusion  and infection. It also allows targeted drug delivery to the  implant [11].    It is crucial to assess the age of patient, dimension of contra-  lateral ear in the case of unilateral microtia, and the dimen-  sions of their gender-matched parent’s ear preoperatively for  achieving equal dimensions between the normal ear and the  reconstructed pHDPE ear. The ear created must be adult  sized as the alloplast does not increase in size.   The vascular Doppler is used for marking superficial tem-  poral artery. The incision is given in the postauricular area  few millimeters behind the new helical rim of the microtic  ear to approach TPF flap. Incision is extended in a curvilin-  ear fashion over the TPF flap to improve the exposure and  also helps to harvest the distal flap of recommended length.  Other approaches may be used, including an Y incision  (Fig. 35.13a), which extends superiorly from the mastoid  area, and the Z incision, (Fig. 35.13b) which exposes the  TPF. These approaches also allow better access to the fascia.    However, they increase the risk of alopecia at the incision  lines and at the apex of a triangular flap.   An anteriorly based skin flap of minimum thickness is  elevated meticulously, and microtic cartilage is excised.  Usually, the inferior portion of the flap is attached initially  to the lobular remnant. If this is malpositioned, this skin  flap may be removed and used as a free graft to improve  skin coverage. A TPF flap, based inferiorly, of approxi-  mately 10.5 by 13.0 cm is raised off the deep temporal fas-  cia and periosteum beneath, superior to the level of the  temporal line. The base of the flap is made wide (around  6 cm) to include additional vascular supply (branches of the  occipital artery, postauricular artery, and the mastoid emis-  sary vein), and the base of the flap is made wide, around  6 cm. The flap must be made as robust as possible, and  loose areolar tissue on the deep surface of the TPF must be  included in it. This tissue, which lies deep to the skin graft,  allows the skin to slide over the underlying tissue. This  resists surface trauma and implant exposure. The pHDPE  framework is then sculpted, fused, and matched to contra-  lateral ear. Prior to implant placement, two flat suction    drains are inserted through the skin of the mastoid. One  drain lies deep to the pHDPE, while the second lies in the  posterior part of the donor site on the scalp. The implant is  placed over the mastoid area and covered with the TPF flap  after checking its anatomic orientation, projection, and  axis. The flap is made to wrap tightly around the implant by  the negative pressure generated by the first drain. The sec-  ond drain functions to remove any serous exudate from the  donor site. The skin flap, which is based anteriorly, is  draped over the TPF. It may also be removed and used as a  free skin graft. Sometimes, the skin at the ipsilateral mas-  toid may not be sufficient to cover the surface of the recon-  structed ear entirely. In such cases, a full-thickness skin  graft may be harvested from the opposing side postauricu-  lar region. A graft taken from this region would provide the  best color and texture match. To cover the back of the ear, a  larger skin graft may be required, which can be harvested  from the inguinal region. After activating the drains, the ear  may be coated with a layer of antibiotic cream and the con-  cave regions may be dressed with gauze. The entire ear is  then covered in a customized cast made of silicone. This  cast prevents seroma, hematoma, or shearing trauma, which  may compromise the viability of the skin graft. This cast  should not be under pressure. A pressure dressing to pre-  vent seromas can be applied over the donor site. All suction  drains may be removed following extubation [11].    The complications of this procedure may be minor, such as a  simple wound infection, or major, such as total flap necrosis  with exposure of the Medpor framework beneath. In case the  implant is exposed or infected, removal may rarely be  required. Late complications include traumatic excoriations  to the re-constructed ear, which should be managed with  good wound toileting or with local skin flaps if required.    Certain traumatic, congenital, or surgical defects may benefit  from auricular prostheses. The choice between surgical and  prosthetic reconstruction is controversial, particularly for  patients. The ideal age for prosthetic treatment is the same as  the age for surgical reconstruction, namely, between 6 and 9  years. The child must be capable of caring for the prosthesis.  In cases of unsuccessful surgical outcome, the prosthetic ear  is one of the options. Prosthetic ear is a suitable option for  the ear defects caused by trauma and disease in adult  populations.    Fig. 35.13 Approach for  temporoparietal flap. (a) Y  shape Incision. (b) Large Z  incision   Tissue adhesives are used conventionally for ear prosthesis  retention because of their low cost and quick results. Tissue  adhesive is an old method and causes skin reaction. It is dif-  ficult to wear and take off adhesive while bathing and swim-  ming. Osseointegrated implant is superior option for  retention, and because of nature sense of prosthesis, ease of  use, long lifetime and retention during daily activities, it is  accepted by patients. An implant-retained prosthesis is pre-  ferred when there is hair on the surface of the defect or when  the patient has excessively oily and perspiring skin. The  prosthesis may be attached to the implant screws using preci-  sion attachments or magnets. Osseointegrated implants are  contraindicated during radiation therapy, as the bone is  demineralized and prone to hard tissue vasculitis, fibrosis,  persistent infections, reduced tissue perfusion, and oxygen-  ation. Osseointegration in such patients is difficult, but may  be attained with hyperbaric oxygen treatment [12].    Impressions are made of both the defect and contralateral  normal ear. Usually, rubber silicone material is used and plas-  ter models are prepared. The plaster models of contralateral  side are used as a reference to sculpt the framework. This is  done using wax or clay. Next, a negative mold is obtained  when the wax is removed, leaving behind a void. Medical-  grade silicone usually of clear shade is mixed with pigments  to create the skin colors of the individual patient. This sili-  cone is packed into the void and cured. After removal from  the mold, the texture and the color of the skin can be repro-  duced to match the contralateral side and adjacent skin [12].    Regardless of the method used, ear reconstruction cannot  provide an appearance that equals auricular prostheses.  Future techniques must focus on emerging tissue engi-  neering technologies that can create bone, cartilage, skin,  and blood vessels. This can provide a novel direction for  the treatment of patients with microtia. The creation of a  natural ear using cultured chondrocytes on a prefabricated  cartilaginous framework is an area of active research, but  still holds some challenge [1]. Creating functional and  durable tissue through tissue engineering can remove the  need for donor sites and revolutionize reconstructive  surgery.    The human ear is a unique structure that is difficult to repli-  cate owing to its complex cartilaginous structure and thin  overlying skin. The ultimate goal of total ear reconstruction  should be creation of an auricle that closely matches the nor-  mal ear in appearance. Several surgical techniques are avail-  able for ear reconstruction. Since microtia is a rare condition,  cases are limited, but at the same time, only a high case vol-  ume can improve success rates. The learning curve is long  and might be at the expense of the patient. Although this  learning curve is unavoidable, it is imperative to curtail its  steepness. Prior to embarking on ear reconstruction, sur-  geons must be familiar with the principles and techniques  involved. It is important to remember that repetition helps us  master the technique.    24 year-old male with Unilateral Left side Grade 3 or Lobule  type microtia. On audiometry testing, hearing was normal  with conductive hearing on left side. External auditory  meatus is absent. He was planned for auricular reconstruc-  tion using autologous costal cartilage. Costal cartilage was  harvested from ipsilateral side. Synchondrotic junction and    floating rib were harvested from the seventh, eighth, and  ninth rib. Framework was prepared as shown in photo (b).  Tragal component is added in framework. Skin pocket was  prepared, and lobule was transposed posteriorly. Framework  was inserted in pocket, and suction was applied for close  adaptation of skin to framework. Stage II surgery was done  after | year. Ear was elevated, and cartilage graft was placed  for support. Graft was covered with temporoparietal fascia  flap and skin grafting done. 6 months postop shows symmet-  ric projection of both ears.    Fig. 35.14 (a) Preop, (b) Framework, (c) Postop, (d) 3 months postop, (e) and (f) Comparison between normal and reconstructed ear after    21 year-old male with Unilateral Left side Grade 4 or Anotia.  On audiometry testing, hearing was normal with conductive  hearing on left side. He was planned for auricular reconstruc-  tion using autologous costal cartilage. Costal cartilage was  harvested from ipsilateral side. Synchondrotic junction and  floating rib were harvested from seventh, eighth, and ninth    rib. Simple Framework was prepared as shown in photo (b).  Skin pocket was prepared using Z-plasty incision. Framework  was inserted in pocket, and suction was applied for close  adaptation of skin to framework. Stage II surgery was done  after 1 year. Ear was elevated, and cartilage graft was placed  for support. Graft was covered with temporoparietal fascia  flap and skin grafting done. 8 months postop shows symmet-  ric projection of both ears.    Fig. 35.15 (a) Preop, (b) Framework, (c) Postop, (d) 3 months postop, (e) and (f) Comparison between normal and reconstructed ear after eleva-    1. Tollefson TT. Advances in treatment of microtia. Curr Opin  Otolaryngol Head Neck Surg. 2006;14:412—22.   2. Brent B. Microtia repair with rib cartilage grafts. Clin Plast Surg.  2002.   3. Quatela V, Thompson S, Goldman T. Microtia reconstruction.  Facial Plast Surg Clin North Am. 2006.   5. Cho BC, Kim JY, Byun JS. Two-stage reconstruction of the auricle  in congenital microtia using autogenous costal cartilage. J Plast  Reconstr Aesthet Surg. 2007;60:998—1006.   6. Wellisz T. Clinical experience with the Medpor porous polyethyl-  ene implant. Aesthetic Plast Surg. 1993;17(4):339-44.   7. Kobus K, Szczyt M, Latkowski I, Wojcicki P. Reconstruction of the  auricle. Br J Plast Surg. 2002;55:645-51.   9. Thadani S, Ladani P. A new method for training of ear framework  creation by silicon dental impression material. Indian J Plast Surg.  2012;45(1):134-7.   10. Ladani P, Valand R, Sailer HF. Ear reconstruction using autologous  costal cartilage: a steep learning curve. J Maxillofac Oral Surg.  2018.   11. Stephan S, Reinisch J. Auricular reconstruction using porous  polyethylene implant technique. Facial Plast Surg Clin North Am.  2018.   12. Tanner PB, Mobley SR. External auricular and facial pros-  thetics: A collaborative effort of the reconstructive surgeon  and anaplastologist. Facial plastic surgery clinics of North  America.2006;14(2):137-45.    Tanzer RC. Microtia- a long term follow up of 44 reconstructed auri-  cles. Plast Reconstr Surg. 1978;61:161-6.   Brent B. The correction of microtia with autologous cartilage graft: I.  The classic deformity. Plast Reconstr Surg. 1980;66:1-12.   Brent B. Technical advances in ear reconstruction with autogenous rib  cartilage graft: personal experience with 1200 cases. Plast Reconstr  Surg. 1999;104:319-34.   Nagata S. A new method of total reconstruction of the auricle in micro-  tia. Plast Reconstr Surg. 1993;92:187-201.   Nagata S. Secondary reconstruction for unfavourable microtia results  utilizing temproparietal and innominate fascia flaps. Plast Reconstr  Surg. 1994;94:254-65.   Nagata S. Modification of the stages in total reconstruction of the auricle:  part I. Grafting the three-dimensional costal cartilage framework  for lobule-type microtia. Plast Reconstr Surg. 1994;93:221-30.   Nagata S. Modification of the stages in total reconstruction of the auricle:  part II. Grafting the three-dimensional costal cartilage framework  for concha-type microtia. Plast Reconstr Surg. 1994;93:23 1-42.   Nagata S. Modification of the stages in total reconstruction of the  auricle: part III. Grafting the three-dimensional costal cartilage  framework for small concha-type microtia. Plast Reconstr Surg.  1994;93:243-53.   Nagata S. Modification of the stages in total reconstruction of the auri-  cle: part IV. Ear elevation for the constructed auricle. Plast Reconstr  Surg. 1994;93:254—66.   Firmin F. La reconstruction auriculaire en cas de microtie. Principes,  methods et classification. Ann Chir Plast Esthet. 2001;46:447-66.   Firmin F. Ear reconstruction in cases of typical microtia. Personal  experience based on 352 microtic ear corrections. Scand J Plast  Reconstr Surg Hand Surg. 1998;32:35-47.    Open Access This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.  org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropri-  ate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.   The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in  a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.   When the body sustains injury, the process of wound healing  will commence. Scar formation is a part of wound healing.  These are described as primary, secondary and tertiary inten-  tion processes [1]. In primary, there is close approximation  of the wound edges, and in the secondary, the edges could  not be approximated. The wound is left open, and the defect  is slowly filled with connective tissue. In the tertiary, how-  ever, there is infection or contamination and there is a delay  until the offending items are removed. This is followed by  primary intention healing.   An ideal scar is a thin line or lines in parallel to the relaxed  skin tension lines (RSTLs) described by Borges [2]. This  should have a natural contour, colour and no distortion of the  surrounding structures.   The scar particularly the facial is not aesthetically pleas-  ing and can cause psychological distress to patients, result-  ing in poor body image, reduced self-esteem, generally loss  of confidence and at times certain social stigma.   Prevention of an unsightly scar is primarily important  requirement to any Surgeons but particularly important to  Facial Plastics and Aesthetic Surgeons.   The origin of the word scar comes from Greek termed  “iskharo” and in French “eschori” and interestingly was first  used in the English language in the fourteenth century.   The primary aim in the management of scar is to produce  an invisible line.   Multiple causes can play a role in unsightly scar forma-  tion. Non-clear wound edges cannot give an aesthetically  pleasing outcome. Nutritional status, co-morbidities such as  diabetes, previously radiotherapy field and habits such as  smoking have a detrimental effect in wound healing and thus    V. Hankovan (Dx!) - A. Sayan  Oral and Maxillofacial Surgery, Poole Hospital NHS Foundation  Trust, Poole, UK    © The Association of Oral and Maxillofacial Surgeons of India 2021    imperfect scars. The most important factor is also the surgi-  cal competence of the operator.    The pathophysiology of wound healing and scar formation is  very complicated [3].   The wound healing is characterised by four separate but  overlapping phases (Box 36.2).   Haemostasis and inflammation occur during the first  4-6 days. During the first few minutes after surgery, there are  vascular contraction and formation of fibrin clot. The ruptured  cell membranes result in the release of inflammatory factors in  order to cause vasoconstriction, which will last for 5—10 min,  and then the vessel dilatation starts. This process can take up  to 20 min. The vessel dilatation is caused by histamine, which,  in turns, allows inflammatory cells to arrive at the wound site.  The platelets also adhere to the site of injury. Subsequently,  the coagulation cascade will be activated. The structure of the  clot will be a fibrin protein network filled with platelets and its  contents. The main inflammatory mediators released by the  platelets are the prostaglandins, leukotrienes, interleukins,  growth factors and cytokines. During the inflammatory phase,  there is also the arrival of neutrophils, macrophages and lym-  phocytes. The main function of the neutrophils is the removal    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1-15-1346-6_36    of the invading materials such as the microbes and products  from the cell death. The macrophages are, however, responsi-  ble for inducing and clearing dying cells, which will result in  improvement of inflammation. The apoptotic cells are cleaned  by the macrophages, and the reparative stage begins. During  this stage, there is migration of the epithelial cells usually after  48 hours and this process continues until the tenth day.  Fibroblasts promote collagen synthesis. The epidermis is  thickened in layers, and the collagen fibres promote dermal  strength. The collagen deposition takes 2—3 weeks, and at this  time, the remodelling phase begins. The collagen fibres will  become rearranged during this period, and the cross-linked  will be aligned along the tension lines. Largely, the maturation  phase can take up to a year or longer depending on the type  and site of wound. Therefore, the inflammatory process plays  a major role in scar formation with the resultant fibroblast pro-  liferation migration and differentiation.   The formal scar can be made better by using scar and scar  reducing agents such as non-steroidal anti-inflammatory  drugs (NSAIDs), minocycline and gene therapy. The main  recognised scar reducing agents are transforming growth  factor (TGF), TGF beta 3, COX-2 inhibitors and angiotensin  receptor blockers [4]. The TGF beta modulating agents are  still undergoing phase 2 trials in order to find out ideal scar  modulating topical or intralesional agents.   Microfat grafting [5] is a technique with great potential in  scar management where fat can be used intralesionally using a  small 0.7 mm diameter cannula. It has been shown to be even  more effective in placing fat in deep dermal layer of the skin  using a 23-gauge needle in a treatment called sharp needle  intradermal fat (SNIF) grafting. However, the work carried out  by Tonnard et al. [6] in emulsifying the fat filtered until a liq-  uid suspension was obtained, called Nanofat, which is injected  using a 27-gauge needle, which conveys excellent outcome.   The ideal scar is an invisible line. There was increased  interest in the recent past on intrauterine surgery to improve  craniofacial clefts with some success and large failures. The  extrauterine scars can present as stretched to depressed,  hypertrophic or at times keloid. The stretched and depressed  scars are as a result of inadequate primary intention manage-  ment. The differences between a hypertrophic scar and  keloid scar are highlighted in Box 36.3.    can arise from small injuries  such as piercing of ears  genetic    Scar management includes prevention, pre-injury treatments  during the healing period and definitive treatment once the  scar is established.   It is essential to take accurate history about any previous  scar formation. If it is known, extra precautions should be  taken, patients should be alerted and incisions along the sus-  ceptible sites should be omitted.   For example, when doing blepharoplasty with a history of  previous hypertrophic scar, we should avoid a subciliary  incision and the treatment should be carried out via a trans-  conjunctival approach. Avoidance of treatment should be  practised, for example, a patient who had keloid on previous  ear-piercing episodes.   Limiting skin stretching during wound healing, facilitat-  ing appropriate wound resting and preventive exercises in  certain sites such as chest and suprapubic areas are  observed. Atkinson et al. [7] reported a randomised control  trial of the effect of tape fixation and the prevention of  hypertrophic scars post-caesarean section with significant  scar reduction.   * scar revision with Z plasty, local flaps and skin grafts.    The latest progress in scar management includes treat-  ment with lasers to reduce angiogenesis, subcision and intra-    dermal fillers. The emulsified fat (NanoFat) with stromal  vascular fraction (SVF) and plasma rich protein (PRP) usage  is the current trend in the non-surgical outcome of scar  management.    The non-surgical modalities of scar management are high-  lighted in Box 36.4, and the description of each is as  follows:    Triamcinolone is the mostly used steroid for scars. The  mode of action when used as an intralesional therapy is in  inhibition of the inflammatory mediators, inhibition of fibro-  blast proliferation, collagen synthesis and inhibition of  TGF—BETA 1 and BETA 2—and enhancement of collagen  degradation and collagenase action in keratinocytes [8].   The published reports, however, give varying outcomes  with dose-dependent side effects such as hypopigmentation,  telangiectasia and dermal atrophy [9]. There is an encourag-  ing outcome, however, in combination therapy when the dos-  age is reduced.    The suggested mode of action is an inhibition of fibro-  blast proliferation and TGF-BETA 1-induced collagen syn-  thesis [10]. Anecdotal results are positive; however, trials  lack adequate controls. Nonetheless, the effect is encourag-  ing in combination therapy with steroid and pulse dye lasers.  Much work is required in controlled studies.    It is an antibiotic and has been used intralesionally in vas-  cular malformation with good outcome [11].   The mode of action is in reduction of collagen synthesis  and increased destruction of collagen by inhibiting Lysyl  Oxidase such as TGF-B1 [12]. Much work is needed in its  definitive usage.    Lasers target three chromophores such as water, melanin  and haemoglobin. Laser-induced tissue hypoxia results in  the breakdown of disulphide bonds of the collagen fibrils.  Pulse Dye Laser (PDL), KTP laser and Nd YAG lasers have  affinity to haemoglobin, leading to collagen necrosis, and  results in reduction of proliferation of fibroblast and depo-  sition of collagen type 3. Ablative lasers remove the scar  layer by layer with minimal thermal injury [13].    This technique is still used in treating irregular scars such  as ice pick scars of acne. The aim is to abrade up to the retic-  ular dermis, allowing epithelialisation to take place. This  treatment causes erythema for a long time, and the symmet-  rical outcome is not guaranteed.   Microdermabrasion is an advancement where there is  high-speed pressurised aspiration-compression system. The  benefit is that it minimises deep thermal injury [14].   Carbon Dioxide (CO,) and Erbium laser resurfacing  supersedes microdermabrasion with minimal thermal dam-  age. Laser resurfacing acts in a different way compared to  the vascular lasers. The vascular laser action is as a non-  ablative principle, whereas CO, and Erbium cause ablation.   Vascular lasers decrease the prominence by destroying  the blood vessels and stimulating collagen remodelling, thus  softening the scar, whereas the ablative lasers such as CO,  and Erbium ablate or vaporise the excessive tissues. CO, can  induce more collagen remodellation and promote wound  contraction [15].   The vascular lasers are used in hypertrophic and keloid  scars. CO, and Erbium are useful in stretched, asymmetric  and irregular scars. There is a restriction as it is not effective  in all skin types as resurfacing can result in excessive pig-  mentation in dark, Asian and African skins.    It is a technique where depressed scars are elevated, and  the controlled trauma can aid in formation of new connective    tissue. This is carried out by custom-made subcision knives  or 20 gauge needles. It can be combined with autologous fat  injection to the subcised areas filling in the space and simul-  taneous laser resurfacing [16].    Synthetic Hyaluronic acid, calcium hydroxylapatite and  bovine collagen are used in aesthetic surgery for voluminisa-  tion. They can be used in treating depressed scars. However,  these agents cannot be used in a larger quantity as they will  cause subcutaneous nodules and inflammation, and in bovine  collagen, there is 3% incidence of allergic history. There is  also a need for repeat injection. Autologous fat has taken  over as a material of choice for filling in scar management.    These sheets are used prophylactically in known patients  for bad scars as well as therapeutically. However, the out-  come for hypertrophic scars is still questionable and  inconclusive.   It appears that controlled studies have shown significant  beneficial outcome in scar volume when the silicone sheets  are used or not used in mirror image wounds. A Cochrane  review of 13 trials involving 559 patients, however, con-    Fig. 36.1 (a) Keloid Scar  right ear lobule. (b) Post-  operative photograph  following scar excision and  one dose of radiotherapy    cludes weak evidence in preventing hypertrophic scars in  susceptible patients [17].   The mechanism of action is in producing hydration to the  scars by occlusion.    It is a perceived therapy that there is positive evidence in  the literature. The largest randomised trial showed no signifi-  cant difference in scar reduction with pressure therapy when  compared to the controlled group [18].    A large uncontrolled study of 135 patients with 166  keloids demonstrated 79.5% response rate with 80% reduc-  tion in scar volume. However, the results are not reproduc-  ible. This treatment causes atrophic, depressed scars with  residual hypopigmentation [19].   Therefore, the usage of cryotherapy particularly on the  face should be discouraged as a modality.    It is an effective adjuvant to surgical excision particularly  to keloid. The effect is caused by inhibition of proliferation    of fibroblasts and neo-vascular blood formation, resulting in  decreased collagen production [20].   The highest cure rate is described in a single dose within  24 hours after surgical excision; however, further studies are  needed to evaluate the dosage and to obtain optimum results  (Figs. and ):    The fat tissue is accepted not only as a simple layer of  insulation and as a storage for energy but also as a complex  endocrine organ, which is intrinsically involved in metabo-  lism and immunomodulatory activities and can provide  multi-source resources for stem cells and other undifferenti-  ated cell population, which is essential for regeneration.   In addition to the adipocytes in the fat tissue, there are  other cell groups that are functionally very important such as  stromal vascular fraction (S VF) and cell-assisted lipotransfer  (CAL). The SVF of adipose tissue is a rich source of epithe-  lial progenitor cells, T cells, B cells and adipose tissue mac-  rophages [21]. Separation of SVF is a time-consuming and  expensive process requiring collagenase treatment and cen-  trifugation. The recent clinical results obtained with Nanofat  grafting where the cells are emulsified show greater value  than the components of SVF used separately.   In Nanografting, a 23 gauge needle is used as a sharp  needle for subdermal fat injection technique (SNIF) fol-  lowed by a 27 gauge needle to superficial layers. In order to  do this, the fat should be emulsified and takes the name, thus,  Nanofat [6].   This now emerges to the forefront in regenerative  medicine due to its ability to differentiate into a variety of    Fig. 36.2 (a) Keloid Scar post-auricular region. (b) Post-operative photograph following scar excision and one dose of radiotherapy    different cells of cell lineage and the anti-apoptotic, anti-  inflammatory, pro-angiogenic immunomodulators and anti-  scarring properties.   Nanofat has shown to improve the aesthetics of hypertro-  phic and keloid scars by improving the texture of the scars in  addition to improving the symptoms of pain and itching [22].   Fat is used in voluminisation initially as foundation micro-  graft just above the periosteum. The second layer is subder-  mal graft followed by subcision and lastly Nanofat injection  using SNIF technique with 23-gauge needle followed by  superficial needle injection using 27-gauge needle. This pro-  cess is to treat depressed scars. Intralesional Nanofat injection  improves hypertrophic and keloid scars. This can be com-  bined with other modalities such as laser resurfacing.    As described above, an ideal scar should be an imperceptible  line parallel to RSTL. The only exception is scar along the  lower lid due to the possibility of ectropion, if incisions are  made in parallel to RSTL.   The aim of scar revision is to re-orientate the scar to fol-  low the RSTLs and correction of adjacent structure  distortion.   Patient understanding, nutrition, expectation and the psy-  chological stability are paramount factors to implement pre-  operatively prior to any scar revision exercises particularly in  burn scars. The timing of the revision is also important as the  remodelling may take up to 12 months.    Nutritional status and the medical history are important  pre-operative considerations. It has been described with cer-  tain evidence that the use of vitamins A, C and E and zinc  have beneficial effects and, at the same time, some herbal  supplements such as arnica, garlic, ginseng and saw palmetto  can impair wound healing [22]. Systemic conditions such as  diabetes and immunosuppression can adversely affect wound  healing. Smoking has proven to cause perilous effect on  healing and wound repair.   Vitamin E refers to a group of ten lipid soluble com-  pounds that include both Tocotrienols and Tocopherols as a  fat soluble antioxidant; it stops the production of reactive  oxygen species formed when fat undergoes oxidation [23]. It  has been identified that alpha-tocopherol, the most biologi-  cally active form of vitamin E, has anti-inflammatory effects  by decreasing plasma C-reactive protein (CRP) levels and  release of pro-inflammatory cytokines. The CRP, a down-  stream marker of inflammation in addition to being a risk  marker for cardiovascular disease, could contribute to ath-  erosclerosis. Alpha-Tocopherol has been shown to decrease  CRP level in patients and has a positive effect in scar reduc-  tion. Topical vitamin E application has been practised in  managing scar 10 days post-suture removal. Anecdotally, in  the last 25 years, good scar outcome has been observed.    In most circumstances, incisions should be made parallel to  the skin surface. A number 11 or 15 blade is ideal. Tissue  handling must be atraumatic. The skin flaps should be held  with non-toothed forceps, and the tooth forceps should only  be used to handle tissues subdermally. Undermining and  constant hydration of edges are essential. In stretched scars,  preservation of the dermis by de-epithelialisation will pro-  vide extra support in correcting the depression. Haemostasis    Fig. 36.3 Z plasty (a) scar  revision. (b) triangular flaps  raised. (c) interposition of  triangular flaps    should be achieved using a bipolar diathermy again minimis-  ing thermal injury to the surrounding areas.   Suturing is done in layers. In areas where supportive ten-  sion is required, resorbable round body needle sutures are  useful. Depending on the site and the extent of the scar,  short- or long-term resorbable sutures could be selected.  With deep suturing as much as possible, the knot should be  buried with skin approximation to achieve ‘eversion’.  Simple-interrupted sutures are preferable in a majority of  areas; however, subcutaneous running sutures could be used  where only gentle approximation is needed.    This is acommon technique used in scar revision to either  change the direction of the scar or lengthen the scar.  Contracted scars can be corrected by plating multiple simul-  taneous Z plasties.   The Z plasty is created by using the original scar as a  central portion, and triangular flaps are raised. Multiple vari-  ations are in Z plasty. In the classical Z plasty, all the limbs  are of equal length and the angle between the flaps is 60°.  The scar will lengthen by 75%. A 30° angle will lengthen by  25%, and 45° will lengthen by 50%. Multiple Z plasties are  useful in long scars, which can be divided into separate seg-  ments, and the angles are contoured or modified depending  on the sites.    This technique is used to irregularise scars so that dimen-  sions of the scar are not perceived by the naked eye. A series  of consecutive triangles are made. It is mirror image on the  opposite side. The arm length should be around 5 mm, and  the angle in-between the flap should be maximum 90°. One  side of the triangle should be in parallel to our RSTL. The    Fig. 36.5 V-Y scar  lengthening correction. (a) V  incision. (b) Triangular flaps  raised. (c) Y closure    triangle are excised, undermined and closed with interdigita-  tion. This technique is very useful in correcting unsightly  hairline scars such as revision of face lift.    This is another technique to minimise the perception of a  long scar. Here, random geometric designs are planned with  corresponding mirror images. The length of the limbs should  be 3-6 mm and at the angle near to 90°, and a W plasty could  be done at the end of the design.    V-Y scar correction (Fig. 36.5a—c) is utilised when there  is an indication on scar lengthening in contracted scars with  ‘trap door deformity’. In contrast, Y-V technique is utilised  where the scar is shortened, removing the “Y ‘extension  (Fig. 36.6a—c).   When repairing wounds in patients who are prone to develop  hypertrophic scars, deep sutures should be placed using  round bodied needles. The suture removal is delayed by an  extra 3-4 days. Applying steri strips after removal of the  sutures adds extra support, and this should be incorporated to  achieve the best result.   Prophylactic intralesional steroids in patients prone to  hypertrophic scars should be considered. Obliteration of the  dead space by appropriate sutures or pressure dressings with  or without drains should be considered to prevent haema-    toma formation. If not, haematoma on its own will spoil the  good work of scar revision.    Extrauterine scarless surgery is not possible. Therefore, care-  ful patient factor and scar characteristics should be studied to  prevent unsightly scar formation and to correct perceptible  scars.   General health and optimising comorbidities are impor-  tant requirements to achieve good scars. Both non-surgical  and surgical options should be available in the armamentar-  ium to the Surgeon.   Nanofat has very positive potential in scar management.  The research on gene therapy using adenovirus as a mediator  to deliver dermal fibroblast is encouraging [24].    Although inflammatory response is traditionally believed  to be a key event for wound healing in adult skin, studies of  foetal wound healing suggest that a high level of inflamma-  tion might prevent good scar formation rather than enhanc-  ing the wound healing process. Therefore, further studies are  needed to confirm if really inflammation is necessary for  wound healing in adult skin. However, at present, we need to  follow the inflammatory process and available evidence of  therapeutic modulators of scar formation.   Furthermore, it is paramount to consider that there are  clinical, histological, biochemical and molecular differences  between hypertrophic and keloid scars. There is marked dif-  ference in the proliferative and apoptotic cell deaths between  the scars, resulting in variable response of different treat-  ments. This should be taken into account in treatment plan-  ning process.   It is also essential to avoid excessive movements that can  stretch the wound and for avoidance of the scar to direct  mechanical forces such as friction and scratching and par-  ticularly earlobe wounds, to minimise the contact with pil-  lows and wound hygiene.   Not least the patient’s involvement plays a vital role in the  management of scars. Variable scales in the literature exist  for reliable and reproducible scar management, for both the  observer, i.e. surgeon, and the patient. The observer opinion    is always influenced by vascularisation, thickness and pig-  mentation. The patient opinion, on the other hand, is influ-  enced by action of itching sensation and thickness of the  scar. Out of the available assessment scales, the patient and  observer scar management described by Draaigers L et al. is  an informative tool in documentation of the progress in the  management of scar, which should be addressed [25].   In summary, a surgeon should have an algorithm to follow  on how to manage scars in normal patients as well as patients  who are prone for hypertrophic and keloid scars (Fig. 36.7).    Scar formation is a part of wound healing process. Facial  scars can be aesthetically detrimental and affect social  stigma. As facial surgeons, we need to achieve ideal scars  with natural contour, colour and limited distortion. It is para-  mount to remember that scar management includes preven-  tion, treatments during the healing period and definitive  management once the scar has been established. We have, in  this chapter, included all the different available treatments  separating them into non-surgical remedies and surgical  techniques. The algorithm, in this chapter, allows a very easy  review process for surgeons who manage stretched,    depressed, hypertrophic and keloid scars.DisclosureAuthors  have no financial conflicts to disclose.    A 27-year-old female patient of Asian ethnicity had an extra  ear piercing to the right earlobe. Within 4 months, she started  to develop a very painful hard lump at the pierced site. Within  the following 6 weeks, it developed into an irregular mass  involving the whole of the earlobe.   Her medical history was unremarkable, and she was not  on any medication.   On examination (Fig. 36.1a), there was an unsightly thick  lumpy scar along the right earlobe. A diagnosis of keloid was  made.   Under a local anaesthetic, the keloid scar was excised and  the earlobe was reconstructed. The next post-operative day  she underwent single dose of radiotherapy (10 Gy) as an  outpatient.   On review, 6 months post-treatment (Fig. 36.1b), she had  no recurrence and on palpation, the skin was soft and  non-tender.    A 48-year-old Caucasian patient who had a considerable  amount of sun exposure presented with an unhappy peri-oral  aesthetics (Fig. 36.84).   Her medical history was unremarkable, and she was not  on any medication.   In one examination, she had loss of volume along the  peri-oral site mainly along the upper lip. The vermillion bor-  der had lost its definition. She had multiple small vertical  subdermal lines, which were crossing the vermillion border.  She also had epidermal thinning.   A diagnosis of aging of the peri-oral area, particularly  upper lip, was made. She, in fact, had epidermal thinning,  subdermal scaring and loss of inter- and intramuscular fat.   The post-operative appearance 4 months later (Fig. 36.8b)  showed excellent volume restoration, much improvement in  the subdermal scaring, better vermillion definition and a new  regenerative skin.    . Broughton G, Janis JE, Attinger CE. The basic science of wound    . Collet C, Laversanne S, Haen P, et al. Micro-re-injection of autolo-    . Tonnard P, Verpaele A, Peeters G, Hamdi M, Cornelissen M,    Declercq H. Nanofat grafting: basic research and clinical applica-  tions. Plast Reconstr Surg. 2013;132:1017-26.    . Atkinson JA, McKenna KT, Barnett AG, et al. A randomised con-    trolled trial to determine the efficacy of paper tape in preventing  hypertrophic scar formation in surgical incisions that traverse  Langer’s skin tension lines. Plast Reconstr Surg. 2005;116:1648-5S6.    . Roques C, Teot L. The use of corticosteroids to treat keloids. A    . Sindel A, Sayan A, Ilankovan V, et al. Percutaneous treatment    of orofacial vascular malformations. Br J Oral Maxillofac Surg.  2018;56:206-11.  ST, Bradner WT. Bleomycin,  1976;7:333-428.    . Tsai RY, Wang CN, Chan HL. Aluminium oxide crystal microderm-    abrasion. A new technique for treating facial scarring. Dermatol  Surg. 1995;21:539-42.   Bowes LE, Nouri K, Bernam B, et al. Treatment of pigmented  hypertrophic scars with the 585 nm Pulsed Dye Laser and the    532 nm Frequency Doubled Nd: YAG laser in the Q-Switched  and variable pulse modes: a comparative study. Dermatol Surg.  2002;28:714—-9.   Orientreich DS, Orientreich N. Subcutaneous incisionless (subci-  sion)surgery for the correction of depressed scars and wrinkles.  Dermatol Surg. 1995;21:543-9.   Neissen FB, Spauwen PH, Robinson PH, Fedler V, Kon M. The  use of silicone occlusive sheeting (Sil-K) and silicone occlusive gel  (Epiderm) in the prevention of hypertrophic scar formation. Plast  Reconstr Surg. 1998;102:1962-98.   Chnag P, Laubenthal KN, Lewos R, et al. Prospective, randomized  study of the efficacy of pressure garment therapy in patients with  burns. J Burn Care Rehabil. 1995;16:473.   Rusciani L, Paradisi A, Alfano C, et al. Cryotherapy in the treat-  ment of keloids. J Drugs Dermatol. 2006;5:591.   Ragoowansi R, Cornes PG, Moss AL, et al. Treatment of keloids  by surgical excision and immediate postoperative single-fraction  radiotherapy. Plast Reconstr Surg. 2003;111:1853.   Zhu X, Du J, Liu G. The comparison of multilineage differentiation  of bone marrow and adipose-derived mesenchymal stem cells. Clin  Lab. 2012;58:897-903.   Broughton G, Crosby MA, Coleman J, et al. Use of herbal supple-  ments and vitamins in plastic surgery: a practical review. Plast and  Reconst Surgery. 2007;119:48-66.   Devaraj S, Leonard S, Traber M, Jialal I. Gamma-tocopherol  supplementation along and in combination with alpha-tocopherol  alters biomarksr of oxidative stress and inflammation in subject  with metabolic syndrome. Free Radic Biol Med. 2008;44:1203-8.  Liu W, Chua C, Wu X, Want D, Ying D, Cui L. Inhibiting scar for-  mation in rat wounds by Adenovirus-Mediated overexpression of  trunated TGF-8 Receptor II. PRS. 2005;115:860-70.   Draaijers LJ, Templeman FR, Botman YA, Tuinebreijer WE,  Middelkoop E, Kreis RW. The patient and observer scar assess-  ment scale: a reliable and feasible tool for scar evaluation. PRS.  2004;113:1960-S.    Open Access _ This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.  org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropri-  ate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.    The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in    a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.    An ancient Chinese proverb “% H 4.32.” observed that  “no one is spared from the ravages of ageing”. A combina-  tion of age, gravity, physiologic contraction of facial muscles  and solar (sun) and chemical (smoking) insults results in  intrinsic and extrinsic changes to the skeleton, muscles and  skin [1]. Preservation of one’s youthful looks has been a goal  of humans regardless of cultures and ethnicities. The search  for this elixir of youth was found unexpectedly in the hands  of cosmetic surgeons. Even with the recent advent of skin  peels, botulinum toxin injections, lasers and injectable filler  injections, the century-old facelift still possesses the most  dramatic improvement to the moderate to severe ageing  lower face when done well.   Facelift or rhytidectomy as its name suggests is a proce-  dure to partially eliminate folds, creases and wrinkles  (rhytids) caused by gravity and degeneration. In effect, the  creation of two large cervicofacial flaps, which, after suspen-  sion and trimming, produces an overall tightening of the skin  and the fascial envelope of the face and neck, results in  restored anatomical structure. Facelift can help to negate  some of these gravitational problems and produce some  intrinsic improvement.    Historically, rhytidectomy was limited to skin elliptical exci-  sions and tightening. The German surgeon, Eugen Hollander,  first described being persuaded by his patient to remove  excessive skin in the temporal, preauricular and postauricu-  lar regions in 1901. With cosmetic surgery frowned upon in    V. Ilankovan (5!)  Oral and Maxillofacial Surgery, Poole Hospital NHS Foundation  Trust, Poole, UK    © The Association of Oral and Maxillofacial Surgeons of India 2021    those times, he did not report his surgery immediately but  only recounted retrospectively that the iatrogenic wounds  when approximated resulted in some tightening in 1912 [2].  The initial reports of rhytidectomy were dominated by a slew  of American surgeons such as Cantrell (1902), Miller (1907)  and German surgeons, Lexer (1906) and Joseph (1912) [3].  The French surgeon Passot wrote an important paper “La  chirugie esthétique des rides du visage” in 1919 where he  illustrated strategically placed forehead, malar, cheek and  submental elliptical incisions to tighten the face for aesthetic  purposes, thus heralding the concept of short scar rhytidec-  tomy (Fig. 37.1).    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1-15-1346-6_37    However, with limited undermining, wounds were closed  under tension, resulting in unsightly scarring. To circumvent  this problem, skin flap only procedures during which only  the skin was raised, undermined for a short distance and  tightened were introduced (Bames 1927) [4].   The results of skin flap only facelift were short term with  limited correction of the ageing face, forcing surgeons to  search for better alternatives. In 1974, Tord Skoog, a Swedish  surgeon, revolutionized facelift concepts by describing the  dissection, elevation and tightening of the superficial fascia of  the face in addition to removing excess skin. He expounded  the importance of retro-positioning the “buccal fascia” and the  platysma for better results. The importance of this technique  was later cemented when the superficial fascia of the face was  clarified as the “superficial muscular aponeurotic system”  (SMAS) by Mitz and Peyronie in a landmark paper in 1976  [5]. Manipulation of the SMAS layer in a superior or supero-  lateral vector became an important part of modern facelift.  Soon, a flurry of papers on the modifications to facelift proce-  dures concentrated on the management of the SMAS.   Treatment of the SMAS layer could be broadly catego-  rized into three methods. They were plication, elevation,  imbrication and SMASectomy [6]. The most conservative of  these methods was plication of the SMAS layer, as it did not  actually involve dissecting the SMAS layer but instead used  sutures to fold the SMAS and achieve a tightening effect [7].  More aggressive management of the SMAS included imbri-  cation, which involved the elevation and repositioning of the  SMAS in a superior or superolateral vector [8]. In standard  SMAS elevation, the SMAS was dissected, lifted off the  parotid fascia and secured to the underlying zygomatic soft  tissues or the deep temporal fascia (Fig. 37.2).    Fig. 37.3 SMASectomy. 1—2 cm of the SMAS is excised superficial to  the anterior border of the parotid    SMASectomy was later described [9]. This required exci-  sion of approximately 1—2 cm strip of the SMAS, superficial  to the underlying parotid fascia, and then tightening were  carried out by suturing the opposing two cut SMAS margins  [6] (Fig. 37.3).   It soon became obvious to the surgeons that skin excision  and SMAS manipulation were only effective in treating the  lower face but not as effective in treating midface ageing. In  particular, the nasolabial fold proved to be a stubborn adver-  sary. The spotlight turned towards the high density, retaining  ligaments such as the zygomatic retaining ligaments, which  prevent effective rejuvenation of the midface using the afore-  mentioned procedures.   The deep plane facelift was described by Hamra to  include the malar fat pad [10]. In this, the dissection and  elevation of the SMAS layer were carried out further to  release the zygomatic retaining ligaments so that more trac-  tion could be obtained from the midface. The orbicularis  oculi and later septal reset were included to improve mid-  face aesthetics, and the term composite facelift was coined  by Hamra [11].   As the facelift landscape progressed, efforts turned almost  full circle towards smaller incisions. Comparisons of differ-  ent published facelifts were unable to reveal an optimal tech-  nique [12] although complications were significant higher in  extensive SMAS procedures.   Attention turned towards having minimal excision, lim-  ited dissection and SMASectomy with imbrication, and in  2001, Saylon and later Fulton et al. described the S-lift [13].  In this technique, the preauricular skin was excised in a pre-  determined S-shape followed by purse-string plication of the    mobile SMAS using a U-shaped purse string suture and an  O-shaped purse string suture. Both sutures were anchored  into the periosteum of the zygoma.   Tonard et al. later introduced the minimal access cranial  suspension (MACS) as a modification to the S-lift [14]  (Fig. 37.4).   In this procedure, he described suspending the sagging  SMAS tissues with cranially directed purse string sutures via  limited incisions that extend from the sideburn to the inferior  helical attachment. Four main differences lie between the  “S” lift and the ‘MACS’ lift. First, the S-Lift pre-empted the  amount of excess skin and excised it via an S-shaped inci-  sion. The MAC lift redraped the excessive skin and removed  it according to the margin. The second difference lies  between point of anchorage as the ‘S-lift’ anchored to the  periosteum of the zygoma, while the ‘MACS lift’ anchors to  the superficial layer of the deep temporal fascia. Third, dur-  ing the S-lift, SMASectomy and imbrication were carried  out, while during the MACS lift, only plication was per-  formed. Fourth, besides the two O and U-shaped sutures, the  MACS lift utilizes a third vertical suspension suture that sus-  pended the malar fat pad, thus reducing the depth of the  nasolabial fold. This area is accessed by extending the tem-  poral hairline incision, and Tonard and Verpaele called this  the extended MACS lift.    Some of the gravitational changes include lateral brow pto-  sis, tear trough, malar palpebral groove, SOOF descent,  malar fat descent, deepening of the nasolabial groove, buccal  fat pad herniation, marionette lines, jowls, loss of neck defi-  nition, submental fat and excess skin [1].   With ageing, a combination of gravitational forces, laxity  of the skin due to loss of elasticity, decreased dermal thick-  ness and loss of dermal appendages results in ptotic, hanging  skin.   The mid cheek’s fat is divided into three compartments  [15] (Fig. 37.5). It is thinnest at the lid-cheek segment and  is thickest in the nasolabial region. The malar fat is also  moderately thick although not as thick as the nasolabial  region.   Accumulation of fat in the cervical region results in loss  of neck definition and submental fat.   Superficial fat and deep fat are separated by SMAS  layer. The superficial fat is separated into five compart-  ments, namely, the nasolabial, medial cheek, middle cheek,    Fig. 37.5 Cheek fat is divided into three compartments. They are lid-  cheek segment (Orange), Malar segment (red) and nasolabial region  (yellow). (Figure adapted and redrawn from Aesthetic Plastic Surgery  2009, Chapter 6 by Mendelson BC)    lateral temporoparietal and inferior orbital fat. Deep fat is  divided into the deep medial fat and suborbicularis oculi fat  (SOOF) [16].   The superficial musculoaponeurotic system (SMAS) is a  fibrous sheath, which was described in a classical paper by  Mitz and Peyronie [5] in 1976, and starts from the galea  superiorly. Superolaterally, it is continuous with the superfi-  cial temporal fascia also known as the temporoparietal fas-  cia. In the central upper face, deep into the superficial fat, the  SMAS layer is invested by the muscles of facial expression,  derived from the embryonic second branchial arch: frontalis,  orbicularis oculi, corrugator supercilii, depressor supercilii  and the procerus. In the middle third, the SMAS is invested  by the nasalis muscles, zygomaticus major, minor, levator  labii superioris alaeque nasi and levator labii superioris.  Laterally, the SMAS is superficial to the parotid fascia and  extends inferiorly to include the platysma muscles.  Inferomedial, the SMAS is invested by the orbicularis oris,  risorius, depressor anguli oris, depressor labii inferioris and  mentalis and is continuous with the platysma.   With the exception of the levator anguli oris and mentalis,  the facial nerve travels deep into the SMAS layer and inner-  vates the muscles of facial expression, making dissection  above the SMAS during facelift safe [16].   An analogy of the retaining ligaments is that they are  rooted in a tree into the periosteum and deep fascial thicken-  ing, and as it approaches the SMAS, it divides into numerous  branches and inserts into the dermis called retinacular cutis  [15] (Fig. 37.6).   Stuzin [17] and Furnas et al. [18] described the retaining  ligaments [17]. The partitioning of separate fascial spaces  and compartments is caused by these retaining ligaments,  which are classified into osteocutaneous and fasciocutaneous  retaining ligaments.   Osteocutaneous retaining ligaments originate from the  periosteum and include the zygomatic and mandibular cuta-  neous ligaments. Stout zygomatic retaining ligaments origi-  nate from the inferior border of the zygomatic arch towards  the junction between the arch and the body and insert into the  dermis of the skin as fibrous septa. It is posterior to the zygo-  maticus major muscle, approximately 3 mm in width,  0.5 mm in thickness and 4.5 cm anterior to the tragus [18].  Loss of support results in malar fat descent.   The mandibular ligament originates from the periosteum  10 mm above the mandibular border, extends along the ante-  rior one third of the mandibular body and inserts into the  dermis [19] (Fig. 37.7). It coincides with the anterior margin  of the jowl.   Fasciocutaneous retaining ligaments include the masse-  teric and parotid cutaneous ligaments also known as the pla-  tysma auricular ligament and coalesce between the superficial  and deep fascia of the face [1].   Masseteric ligaments originate from the parotidomasse-  teric cutaneous ligaments, and: loss of support results in    Fig.37.6 Retaining ligaments (RLs) insert into the subcutaneous layer  as retinacular cutis. It is likened to a tree by Mendelson BC [15]. (Figure  adapted and redrawn from Aesthetic Plastic Surgery 2009, Chapter 6 by  Mendelson BC)    Fig. 37.7 Osteocutaneous ligaments comprising the zygomatic retain-  ing ligaments (ZRLs) and the mandibular retaining ligaments (MRLs)    Fig. 37.8 Fasciocutaneous retaining ligaments comprising the masse-  teric retaining ligaments (MasRLs) and the parotid cutaneous ligaments  also known as platysma auricular retaining ligaments (PARLs)    facial jowling. Parotid cutaneous ligaments are formed by  the posterior border of the platysma, which had receded into  fascial condensation. It is fused with the parotid fascia, is  attached to the overlying skin and provides firm anchorage  between the platysma and the dermis in the inferior auricular  region (Fig. 37.8).    Surgery can be carried out either under general anaesthesia  or under local anaesthetic with or without sedation.   Local anaesthesia comprising Lidocaine 2% with adrena-  line 1:80,000 is infiltrated in the zygomaticofacial region,  infraorbital, mental, greater auricular (Fig. 37.9) and the  lesser occipital nerves.   Tumescent solution reconstituted with | L of saline,  50 mL of 1% lidocaine, 1 mL of adrenaline 1:1000 and 6 mL  of 8.4% Sodium Bicarbonate is then injected subcutaneously  after stab incisions are placed in the temporal, preauricular,  postauricular and submental regions. Approximately 300 mL  of tumescent solution in all is injected.   In both approaches, infiltration of Tumescent solution in a  subcutaneous plane is essential to carry out atraumatic dis-  section. In our practice, 95% of standard facelift are carried  out with simultaneous neck lift, as we feel it would be impos-  sible to mobilize the attenuated soft tissue to achieve sym-  metry and an unoperated look of the midface without  bringing attention to the neck aesthetics.    The incision lines are divided into four sections: temporal,  preauricular, postauricular and scalp extension. The tempo-  ral component is either into the hairline or just at the hairline/  sideburn border. The latter has the advantage of not moving  the sideburn position; however, it would give a telltale sign  of a visible scar. In the former approach, the sideburn area  may get lifted into the temporal area and the scar will be hid-  den. This position should be made in conjunction with dis-  cussion with the patient, and suitability of the incision should  be selected.   The preauricular marking could be a pre-tragal, intra-  tragal or post-tragal. The latter can distort the tragal projec-  tion, and the pre-tragal will give a visible scar. We prefer an  intra-tragal approach and obtain the tragal projection by  placing a subcutaneous anchor suture before the final closure  in order to maintain the natural concavity and simultane-  ously achieve an invisible scar (Figs. 37.10 and 37.11).   The postauricular incision should be a few millimetres  into the postauricular area from the sulcus so that post-  operatively the scar will settle down comfortably into the  sulcus. The scalp extension is carried out by multiple W or Z  plasty type incisions in a trichophytic fashion to minimize  hair loss and to have an invisible scar (Fig. 37.12).   A 2.5 cm curvilinear incision parallel to the mandibular  contour is the submental incision to the neck lift section in  order to expose the anterior border of the platysma and the  platysmal dissection.    The submental flap dissection is carried out at first to expose  the platysma muscle as much as possible (Fig. 37.13).    Fig. 37.10 Temporal to preauricular incision (red). Occipital or scalp  extension (broken line)    Fig. 37.11 Hairline to tragal incision (red). Occipital or scalp exten-  sion (broken line)    Next, the scalp and postauricular dissection is carried out.  The anterior border of the sternocleidomastoid muscle and  posterior border of the platysma are exposed, and a cavity of  the neck is connected anteriorly and posteriorly (Fig. 37.14).  The next step is to focus on the temporal and preauricular  dissection. In the temporal, the deep part of deep temporal    fascia is exposed, which we use as an anchor point to the  SMAS suturing (Fig. 37.15). The preauricular dissection will  expose the zygomatic ligaments, lateral end of the orbicu-  laris oculi and the anterior border of the parotid—masseteric  fascia with careful attention towards the buccal branch of the  facial nerve (Fig. 37.16).   The preauricular, neck and postauricular dissection should  now be in one cavity.    Fig.37.14 The postauricular flap is then connected to the cervical flap  and the submental region made previously    7 » a  ©Association of Oral and Maxillofacial Surgeons of India    Fig.37.16 After the deep temporal fascia is exposed, dissection is car-  ried out in a different plane subcutaneously to raise a skin flap    SMAS elevation and management are carried out in various  forms. We elevate the SMAS in an inverted L fashion  (Fig. 37.17) starting at the preauricular plane, and the supe-  rior limit is at the lateral end of the zygomatic arch. The ante-  rior dissection passes to the parotid-masseteric fascia  (Fig. 37.18). The inferior dissection is to join the subplatys-    Fig. 37.17 An inverted L shape incision (blue lines) is made on the  SMAS stopping short of the parotid fascia. The shorter limb is just below  the zygomatic arch, while the longer limb is in the preauricular region    Fig. 37.18 Cut SMAS peeled anteriorly to show underlying parotid.  Facial nerve exits the parotid deep into the SMAS. Deep into these are  the masseter muscles followed by the buccinator muscles with horizon-  tal muscle striations    mal plane at the angle of the jaw with consideration to avoid  damage to the two or three cervical branches. In our practice,  the elevated SMAS is anchored in a superior direction to the  deep part of the deep temporal fascia (Fig. 37.19).   Our platysma dissection and plication are in four steps.  The anterior border of the platysma is sutured in the midline  [20] (Fig. 37.20). In some patients with short neck, the pla-  tysmal suturing needs to be hitched to the body of the hyloid  bone. In some patients, a release of the inferior border of the  platysma muscle at this area could also be considered. Then,    ©Association of Oral and Maxillofacial Surgeons of India  Fig. 37.19 The cut SMAS is then advanced superiorly and sutured to    the deep temporal fascia with 3/0 Polygluconate (Maxon, Tyco Health  UK Ltd., Gosport PO130AS, UK) (blue line)    Fig. 37.20 The medial edges of the platysma are sutured to each other  at the midline in a corset manner    Fig. 37.21 A submental incision is made (white outline). Corset  sutures are done twice, and the suture is plicated to the mastoid fascia  on both sides    the lateral border of the platysma muscle is sutured to the  anterior border of the sternocleidomastoid muscle. The third  step is in platysmal plication is placing a cinch suture, which  is placed joining the two anterior borders of the muscles in  the midline and, after catching the platysma muscle in two or  three areas, hitched the sternocleidomastoid muscle and the  final anchor into the mastoid periosteum (Fig. 37.21).  Depending on the neck anatomy, we sometimes place a sec-  ond cinch suture about 5-6 mm below the first to avoid bulg-  ing of the submandibular gland.    Meticulous haemostasis is done with bipolar electrocautery  throughout the procedure. The cervicofacial flaps are draped  over the margins in a superolateral vector with much empha-  sis on the superior than the lateral direction (Fig. 37.22).  Final anchoring is done with two key sutures that are placed  along the helical attachment and the superior aspect of the  postauricular incision. Cuts are made on the excess skin, per-  pendicular to the flap margin, stopping just short of it  (Fig. 37.23). This allows the margins to be visualized when  trimming the excess skin. If a tragal incision was made, the  skin can be thinned and trimmed to mimic tragal shape and  skin during closure at the tragus. Dog ears are preferably  removed at the apex rather than in the ear lobe region. The  ear lobe is then replaced 15° posterior to the vertical position  to reduce the telltale signs of facelift procedures. Layered  repaired is then carried out in the final closure.    Fig. 37.22 Excess skin is draped in a superolateral vector over the  margins and excised    Fig. 37.23 Cuts are made perpendicular to the flap margin stopping  short of the margins and then excised accordingly    There are different ways of providing this final exercise. We  apply antibiotic topical ointment followed by non-sticky  dressing to the pre- and postauricular area and an adjustable  Velcro band. In the literature, however, various pressure  dressings are applied.    37.5 Post-operative Management  Velcro bands are removed on a daily fashion. Wounds are    cleaned followed by topical ointment and reapplication of  the Velcro band.   The patient is placed on antibiotics and painkillers for a  week. Sleeping is done with the head elevated by 2-3 pil-  lows. The patient is seen on the day after the surgery to  ensure that there is no haematoma. If drains are placed, they  are removed during this time.   Facial bandages are placed between 2 and 5 days. Sutures  are removed 7—10 days later. The wounds are kept moist with  antibiotic ointment such as Tetracycline 3% or Mupirocin  ointment 2% (Figs. 37.24a, b and 37.2S5a, b).    Post-operative complications of facelifts include post-  operative haematoma, skin necrosis, sensory and motor dis-  turbances, obvious scarring, seroma, alopecia, auricular  deformity and dyspigmentation [21]. Detailed informed  consent should be obtained from patients prior to the  surgery.    A thorough medical history is needed prior to surgery.  Antiplatelet medications such as Aspirin, Clopidogrel,  Dipyridamole and powerful anticoagulation drugs such  as warfarin will have to be stopped after consultation  with the patient’s prescribing physicians. Patients on  herbal or traditional Chinese medications such as ginkgo  biloba and Cordyceps will also need to be stopped before  surgery.   Haematoma formation is by far the most common com-  plication with some papers reporting up to 15% [21].  Expanding haematoma usually happens in the first 24  hours and must be evacuated. Smaller haematoma can be  aspirated, and pressure bandage is placed for pressure  haemostasis. Meticulous haemostasis with bipolar dia-  thermy is mandatory for facelift procedures. The flap and  the underlying bed should be scrutinized for bleeding  spots with a good head light or fibre optic light attached to  a retractor. Brisk bleeding from larger vessels should be  ligated. Adjunctive measures including fibrin glue [22,  23] and platelet gel and facelift bandages have been  explored.   Large haematoma are a cause for concern and need to be  evacuated. They can cause problems in healing including  skin ischaemia.    Fig. 37.24 (a) Pre-operative profile view showing excess loose skin,  jowling, submental fat and deep nasolabial fold. (b) Post-operative pro-  file view after facelift and platysma plication. Excessive skin had been    Ischaemic changes and flap necrosis can occur due to circu-  latory disturbances. This can happen when the flap is too thin  or had underwent extensive undermining and exuberant cau-  tery, closed under excessive tension or compromised by  excessively tight bandage compression. The incidence ranges  between 1.1 and 3% [24]. Venous congestion or arterial  obstruction can result in skin ischaemia and necrosis. Large  unevacuated haematoma separates the flap off the underlying    bed during which perfusion is only by the vessels supplying  the flap. This causes the areas furthest away from the perfus-  ing vessels to be at risk of ischaemia.   Necrosis of the skin is more common in the postauricular  than the preauricular region.   Application of nitroglycerin paste may help to encourage  vasodilation when done in the early stages [25]. Conservative  treatment to allow healing via secondary intention followed  by laser, excision of the scar with repair via rotation flaps can  be carried out at a later stage.    Fig.37.25 (a) Pre-operative profile view showing excess skin, slight jowling, submental fat and severe loss of neck definition. (b) Post-operative    Scarring can occur when the wounds are closed under exces-  sive tension or if the incisions are placed at an inappropriate  position due to poor design. Skin slough and necrosis of the  flap can lead to severe scarring. Patients who are more prone  to hypertrophic scarring or keloids should be warned. Wound  tension can develop and cause scarring if there is excessive  removal of skin or if undermining of the flap is inadequate.   Treatment of scarring includes conservative treatment  with antibiotic ointment such as Tetracycline cream 3% or  Bactroban cream. This is followed by steroid injections such  as triamcinolone acetate, application of silicone sheet or gel  dressing. As the scar improves and stabilizes, it can be  lasered, excised and revised.    Sensory disturbances occur invariably due to the dissection  and separation of the facial planes during the facelift proce-    dure, but this usually occurs temporarily and resolves in 1  year.   The most common sensory disturbance occurs to the great  auricular nerve. The greater auricular nerve crosses the ster-  nocleidomastoid muscle at approximately 6.5 cm inferior to  the external auditory meatus and travels superiorly to supply  the postauricular region.   Injury to this nerve can be temporary or permanent due to  dissection over the postauricular, mastoid region and to a  lesser extent in the cervical region. This results in numbness  of the ear lobe and postauricular area.    Keeping away from the planes that the facial nerve travels in  is the safest method to avoid motor nerve problems. The  facial nerve branches course through the parotid gland and  exits the parotid gland to travel deep to the SMAS layer  before innervating the muscles of facial expression. Care    should be taken when dissecting beyond the parotid or when  dissecting deep into the SMAS layer.   Facial nerve injury ranges from 0.4 to 2.6% [21]. The  most common motor nerve damage is the marginal man-  dibular nerve followed by the temporal nerve and then the  buccal branch. Neuropraxia from exuberant retraction, cau-  tery heat and compression can result in temporary or per-  manent loss of the motor function. The marginal mandibular  branch courses in the superficial layer of the deep cervical  fascia, deep into the platysmal layer, and may be damaged  when dissecting in this region. The temporal branch of the  facial nerve courses just deep to the superficial temporal  fascia and travels 0.5 cm anterior to the tragus and then  obliquely to 1.5 cm above the lateral edge of the  eyebrows.    “Pixie or elf-like” ear is a stigma of facelift. The ear lobe  should be repositioned in a tensionless fashion, and the ear  lobe should be placed 15° posterior to the vertical axis of the  pinna [6]. Over resection of the flap at the base of the auricle  as well as failure to place subcutaneous stay sutures on the  facial flap at the ear base can result in the ear being pulled  inferiorly.   Pixie ears can be revised by releasing the base of the auri-  cle and creating a new ear lobe.    The facelift remains the single most powerful method in facial  rejuvenation for the moderate to advanced ageing face. It has  developed from small elliptical incisions and closure to full  facelift with simultaneous neck lift. A variety of techniques  have been described contributing to its evolution including  SMAS layer management, standard facelifts, composite face-  lifts, platysmal plication and smaller flaps such as the MACS  lift and S-lifts. The standard face and simultaneous neck lift  can treat most of the problems of the mid and lower face as  well as the neck. An intimate understanding of the anatomy of  the face, appropriate choice of the facelift design and meticu-  lous execution are paramount in giving the patient an ideal  outcome while avoiding the possible complications.    A 67-year-old Caucasian lady presented with unhappy  aesthetics of her face. She had had a considerable amount  of sun exposure over the years. Her medical history was  unremarkable.   On examination she had multiple minor and major  wrinkles on her face. On examination of the mid face, she  showed descending SOOF and malar fat pads. She had  prominent folding of the nasolabial fold and loss of man-  dibular border definition. Her neck was a good shape for her  age (Fig. 37.26a, b).   She underwent a standard facelift without a neck lift and  simultaneous autologous fat augmentation malar, chin and  perioral areas.   The post-operative profile shows aesthetically pleasing  contour with an unoperated look (Fig. 37.26c, d). A majority  of ageing changes have been removed. She ideally should  undergo perioral laser resurfacing to improve the skin  quality.    A 73-old lady presented with ageing changes and was  unhappy with the mid and lower face. She was concerned  about the aesthetics of her neck (Fig. 37.27a, b).   On examination, the mid face showed malar fat descent  with prominent nasolabial fold. She had marked marionette  lines, pre-jowl] sulcus and prominent jowls. Examination of  the lower face showed platysmal bands and loss of mandibu-  lar neck definition with submental fat projection.   She underwent a standard face and neck lift with platys-  mal and SMAS plication.   Three month post-operative photograph shows correction  for the ageing changes and a pleasing facial and neck profile  (Fig. 37.27c, d).    Fig.37.26 Standard face and neck lift with platysmal and SMAS plication. (a, b) Pre-operative appearance demonstrating wrinkles in frontal and  profile view. (c, d) Post-operative appearance demonstrating wrinkles in frontal and profile view    Fig.37.27 Standard face and neck lift with platysmal and SMAS plication. (a, b) Pre-operative appearance demonstrating wrinkles in frontal and  profile view. (c, d) Post-operative appearance demonstrating wrinkles in frontal and profile view    References 13. Fulton JE, et al. The S-Lift facelift featuring the U-Suture and  O-Suture combined with skin resurfacing. Dermatol Surg.  F : i 2001;27(1):18—22.  I Se 1 ae Chine apes thee Bry Quah Melon Sie: 14. Tonnard P, et al. Minimal access cranial suspension lift: a modified  i lla es 5 Die k Hee ehaneete: Tay 4 h M. edit S-Lift. Plas Reconstr Surg. 2002;109(6):2075-86.  Cee a ee ee > CCUNOF. 15. Mendelson BC. Aesthetic plastic surgery. Saunders Elsevier; 2009.  Handbuch der Kosmetik. Leipzig: Von Veit; 1912. p. 688. Chapter 6, pp. 53-71  3. Mangat DS, Frankel IK. The history of thytidectomy. Facial Plast 16 Waren RI, etal, Face lift, Plast Reconstr Surg. 2011:128:747¢-64e.  Fi ak a eee pee : eetcedes 17. Stuzin JM, Baker TJ, Gordon HL, Baker TM. Extended SMAS dis-  se arse ee a alae hea section as an approach to midface rejuvenation. Clin Plast Surg.  Quality Medical Publishing; 2004. p. 4. 1995:22(2):295-311  ay eM Poncue we he Sapetiiet suMpenl arene One. Sy: 18. Furnas DW. The retaining ligaments of the cheek. Plast Reconstr  tem (SMAS) in the parotid and cheek area. Plast Reconstr Surg. Surg. 1989;83:11-6  PT eC pee bs: ‘ y : : 19. Alghoul M, Codner MA. Retaining ligaments of the face: review of  6. Hankovan V. Recent advances in face lift to achieve facial balance. anatomy and clinical applications, Aesth Surg J. 2013:33(6):769-82  J Maxillofac Oral Surg. 2017;16(1);3-12. . 20. Sebasan T, Ilankovan V. Plication of the platysma. Br J Oral  7. Webster RC, Smith RC, Papsidero MJ, Karolow WW, Smith Maxillofac Surg. 2006;44(4):325  KF. Comparison of SMAS plication with SMAS imbrication in face eY. Biosth: TD: et ‘al Face-li ft Sonnlioations Facial Plast Suep  lifting. Laryngoscope. 1982;92(8):901-12. ; 20)12:28-260-72 , ; : ,  & eee fae e yews ia eet ae air 22. Griffin JE, Jo C. Complications after superficial plane cervico-  9 re ss DC Hn nits i Ae cen ae ‘ : Re . G S facial rhytidectomy: a retrospective analysis of 178 consecu-  : 1 5644 00: 509. ‘S ‘i — . Seniena ae tive facelifts and review of the literature. J Oral Maxillofac Surg.  eae: F : 2007;65(11):2227-34.  10. Hamra ST. Approaches to rejuvenation of the upper face. Aesthet 23, Zoumalan R, Rizk SS, Hematoma tates I drainless deep-plane face-  Sue 1 ZOD 20 Se. : ‘ lift surgery with and without the use of fibrin-glue. Arch Facial  11. Hamra ST. The role of the septal rest in creating a youthful Plast Surg. 2008;10:103-7  eyelid Cheek complex antacid rejuvenalon: Bidse Reconat Sty: 24. Baker DC. Complications of cervicofacial rhytidectomy. Clin Plast  2004;113(7):2124-41. . : . : Surg. 1983;10:543-62.  peel DE ee ME ee ee ee 25. Niamtu J. Cosmetic facial surgery: Elsevier Mosby; 2011. p. 354.    Open Access This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.  org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropri-  ate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.   The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in  a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.    38.1 Introduction  The nose occupies the centre of the face and receives enor-  mous attention as a key aesthetic element. It is also an impor-  tant organ contributing to vital functions of breathing and  olfaction. A nose with ideal proportions creates a harmoni-  ous balance of aesthetic and psychological wellness. Whilst  a rhinoplasty can significantly improve the quality of life of  patients, there may be associated complications and undesir-  able outcomes. It is imperative that the surgeon desiring to  practise the art and science of rhinoplasty should be familiar  with the essential basics before embarking on this journey.  The aim of this chapter is to provide a clinical overview of  the spectrum of rhinoplasty in an easily comprehensible  manner. The primary section is focussed on the key elements  of anatomy, diagnosis and documentation prior to any surgi-  cal procedure on the nose. Basic operative techniques includ-  ing approaches, septoplasty, osteotomies and grafts are  described in the next section. The management of most com-  mon nasal deformities is covered in the last section.    The nose is a complex anatomic unit composed of skin, sub-  cutaneous tissue and fibro-fatty tissue draped over a complex  osteocartilaginous framework [1]. Understanding its overall  morphology along with other characteristics helps in accu-  rate diagnosis and management of various deformities.  Based on the framework, the nose can be divided into exter-    Electronic Supplementary Material The online version of this chap-  ter (https://doi.org/10.1007/978-98 1-15-1346-6_38) contains supple-  mentary material, which is available to authorized users.    N. A. Nasser (5)  Barts & London NHS Trust, Whipps Cross University Hospital,  London, UK    © The Association of Oral and Maxillofacial Surgeons of India 2021    A. Skin and underlying tissues: The features of nasal skin  including color, consistency and thickness can vary  between patients and are important determinants of out-  come of rhinoplasty. Skin thickness varies in different  parts of the nose and at different stages of life. The aver-  age skin thickness is the greatest at the radix (measuring  1.25 mm) and the least at the Rhinion (0.6 mm) [2]. The  supratip area has abundant sebaceous glands especially  in adolescent males. Skin thickness is reduced in the col-  umella and mid-alar area and increased in the alar base  area. Both the thickness of the skin and the presence of  sebaceous glands in the caudal half of the nose make it  difficult to achieve an ideal result in a predictable  manner.   Beneath the skin and above the underlying osseocarti-  laginous framework are the layers of the superficial mus-  culoaponeurotic system (SMAS), fibromuscular layer,  deep fatty layer, and periosteum/perichondrium [3]. The  SMAS of the nose is the continuation of the sheath that  extends across the entire upper half of the face with adi-  pose tissues, vertical fibres and septi, extending to the  skin. Under the SMAS is a layer of thin fibrofatty tissue  that divides the superficial and deep muscles of the nose  [4]. The deep fatty layer separates the fibromuscular  layer from the underlying nasal framework. Major blood  vessels, lymphatics and nerves run within it. Deep to this  layer is the periosteum of the nasal bones and the peri-  chondrium of the cartilaginous frame. The avascular  plane of dissection is in the supra perichondrial plane just  below the fibrofatty SMAS layer.    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1-15-1346-6_38    Fig. 38.1 Nasal anatomy  landmarks—frontal view. (A)  Clinical picture, (B) Line  diagram: (a) Radix, (b)  Dorsum, (c) Tip lobule, (d)  Alar lobule, (e) Tip, (f) Alar  base, (g) Columella, (h)  Philtrum    B. External Vault  The nose is divided topographically into thirds as shown  in Figs. 38.3 and 38.4.   Upper third: The nasal bones constitute the upper one  third. This part of the nose is pyramidal in shape, the nar-  rowest portion being at the intercanthal line. Nasal bones  vary in length and become thinner as they extend cau-  dally toward the Rhinion. The nasal bones are attached to  the frontal bone above at the radix which forms the fron-  tonasal angle. They articulate with the ascending process  of the maxilla. Caudally, the nasal bones overlap the  upper lateral cartilages [Keystone area] [5].   Middle third: This contains the paired upper lateral  cartilages (ULCs) and is referred to as the cartilaginous  vault. The ULCs are fixed above to the under-surface of  the nasal bones and fused with the septum, and they sepa-  rate from the septum as they extend inferiorly. An impor-  tant surface landmark in this region is the external lateral  triangle; bounded above by the upper lateral cartilages,  laterally by the frontal process of the maxilla, and cau-  dally the cephalic border of the lower lateral cartilage.    The angle between the caudal border of the upper lateral  cartilage and the septum is usually 10—15° and consti-  tutes the internal nasal valve (Fig. 38.5a, b).   Lower Third: The lower third or lobule of the nose is  further subdivided into the tip, supra tip and infra tip  regions. These specific areas of the lobule are formed by  variations in the shape, size, and angles of the lower lat-  eral cartilages (LLCs). The form of the lobule is defined  by the tip or apex of the nose. The area defining the over-  lap of the LLC and the caudal aspect of the ULC is called  the “scroll” area and has a fibrous attachment. The size of  the scroll area along with the slope of the lateral crus con-  tributes to the bulbosity of the lobule.   The lower lateral cartilages have four essential com-  ponents: the medial crus, intermediate crus, dome and the  lateral crus (Fig. 38.6a, b, c): The cephalic edge of the  domal segment of the intermediate crus is responsible for  the aesthetic point known as the pronasale. The supra tip  is immediately cephalic to the pronasale. The infra tip is  located between the pronasale and the apex of the nos-  trils. The infra tip region should have a gentle curve that    Landmark Definition  1. Nasion Depression at the junction of the nose  with the forehead  Deepest point at the root of the nose  Radix Area centred around the nasion.  3. Nasal Part of the nasal frame made up of the  pyramid bilateral nasal bone and frontal process of  the maxilla    4. Keystone area Junction of the perpendicular plate of the  ethmoid with the septal cartilage at the  dorsum of the nose   5. Rhinion The point located at the  osseocartilaginous junction over the  dorsum of the nose   lobule posteriorly by the anterior nostril edge,  superiorly by the supra tip area and  laterally by the alar grooves    7. Nasal tip The most anterior point of the lobule  8. Anatomic Most anterior projected portion of the  dome lower lateral cartilages between the    medial and lateral crus  9. Tip defining Summit of the domes. Most projecting  points (TDP) area on each side of the tip that produces  external light reflection  10. Supratip area Area just cephalad to the nasal tip at the  caudal portion of the nasal dorsum  11. Infratip Portion of the tip between the tip defining  lobule points and apex of nostrils  12. Tip projection Distance from the most projected portion  of the tip to the most posterior point of  the nasal—cheek junction  13. Alar groove Oblique skin depression between the tip  and the ala    777  Landmark Definition  14. Supra-alar Groove immediately cephalad to the alar  crease crease  15. Sub-nasale Junction of columella with the lip  Upper 3rd  Middle 3rd  Lower 3rd    slightly projects inferiorly to the alar margins. The  medial-lateral crura complex forms a tripod that is an  essential concept to understand for correction of tip  deformities. The lateral crura form the two cephalic lat-  eral legs while the medial along with the intermediate  crus form the caudal leg of the tripod (Fig. 38.7a, b, c).   Medial crus: The medial crus has two distinct seg-  ments: the footplate and the columella. The footplate var-  ies in size and in the degree of lateral angulation, which  governs the width of the columellar base.   Intermediate crus: It extends between the medial crus  and the lateral crus. The length and width of the intermedi-  ate crus control the configuration of the infra-tip lobule.   Dome: The domal segment is the narrowest and  thinnest portion of the lower lateral cartilage, yet is the  most important in relation to the tip shape. In an ideal  nose, the cephalic edges of the paradomal segments are  in close approximation and the caudal portions are  divergent. Whenever the cephalic margins diverge, they  result in widening of the nasal tip. A wide domal angle  with increased interdomal width results in a boxy tip.   Lateral Crus: It constitutes the larger component of  the nasal lobule. It is narrow anteriorly, widens in the  mid-portion and narrows again laterally. The anterior  portion of this cartilage can curve with different angula-  tions and controls the convexity of the ala. The lateral  crus also provides support to the anterior half of the alar  rim. This cartilage is usually oriented at a 45° angle to the  vertical facial plane. Narrowing of the angle between the  dorsum and the long axis of the lower lateral cartilage    Fig. 38.5 Nasal valve; (al, a2) line diagram, (b) clinical photograph   Several fibrous attachments exist joining the cartilages  to each other, namely, lower lateral cartilages to the upper  lateral cartilage, from one lateral crus to the opposite in  the supratip area (the Pitanguy ligament), dense fibrous  bands between the caudal septum & the medial crura and  between the medial crura themselves [6].    Muscles (Fig. 38.8): The muscles of the nose are divided by  their functions into four categories; elevators, depressors, com-    pressors, and dilators. The procerus, levator labii superioris  alaeque nasi, elevates and shortens the nose. These muscles are  important because they assist in opening the nasal valves. The  depressor muscles consist of the nasalis and depressor septi.  On contraction, this group of muscles adversely affect the tip  rotation by displacing it inferiorly and elevating the lip superi-  orly [5]. The transverse nasalis muscle forms the compressor,  while the dilator naris has the opposite function.   Blood Supply and innervation: Both external and  internal carotid arteries contribute to the vasculature of the  external nose (Fig. 38.9). The major blood supply is from    Fig. 38.6 Lower lateral cartilage (al, a2) Diagrammatic representation and (b, c) clinical pictures    three vessels: the dorsal nasal artery—a terminal branch of  the ophthalmic artery, the angular and superior labial arter-  ies from the facial artery. The lateral nasal artery (branch of  the angular artery) forms a plexus with the dorsal nasal  artery, branches of infra-trochlear artery, and the external  branches of the anterior ethmoidal artery. A small contribu-  tion is also received from the lateral branches of the infra-  orbital artery.   Sensory innervation to the nose is provided by the maxil-  lary and ophthalmic branches of the fifth cranial nerve [7].    The internal nose is divided by the “midline” nasal septum.  Anteriorly, the septum forms the medial boundary of the  nasal vestibule whose lateral wall is formed by the lower lat-  eral cartilages and their attachment to the pyriform rim.   The deeper part of the nasal cavity is bounded laterally by  the medial wall of the antrum, medially by the osseocarti-  laginous septum, superiorly by the ethmoid and the sphenoid  bones and inferiorly by the palatal process of the maxilla and    Fig. 38.7 Nasal tripod; (a) clinical photograph, (b) line diagram showing medial crus (yellow), intermediate crus (red) and lateral crus (grey) (c)    the palatine bones. There are thin, curved, bony prominences  in the lateral wall called the inferior, middle, and superior  concha. The cephalic portion of the lateral nasal wall is  bound with the ethmoid cells, interposed between the lateral  wall of the nasal cavity and the medial wall of the orbit.    The septum is partly cartilaginous and partly bony. The eth-  moid perpendicular plate forms the upper bony septum and  is continuous with the frontal bone and the cribriform plate.  The lower bony septum is composed of the vomer and nasal  crest of the maxilla (Fig. 38.10a, b).    The cartilaginous septum is formed by the quadrangu-  lar cartilage that extends from Rhinion to the supratip area  and supports the dorsum and the tip complex. Inferiorly,  the cartilagenous septum is attached firmly to the anterior  nasal spine and the maxillary crest. The junction between  the dorsal and caudal portion of the cartilaginous sep-  tum is called the “anterior septal angle”. There is tenu-  ous attachment of the perichondrium and periosteum at  the junction of the bony and cartilaginous septum. The  membranous septum lies above the cephalic margins of  the paired medial crura. It encases fibrous bands between  two layers of soft tissue covering and the depressor septi  muscle.    (elevator)  Dilator naris  anterior  Levator labii superioris  alaeque nasi (elevator)  Compressor    Fig. 38.10 (a) Anatomy of nasal septum, (b) line diagram with landmarks    Local  General/Systemic Facial Nose  Airway/breathing Intercanthal distance Skin quality  Mouth breathing  Bleeding disorders _ Inter-eyebrow distance Nasal bone—width, length and symmetry  Hypertension Frontal-bossing/glabellar projection | ULC (Upper Lateral Cartilage)—width and symmetry  Diabetes/ Upper lip position LLC (Lower Lateral Cartilage)  immunosuppression ¢ Cephalic malposition  ¢ Interdomal distance  ¢ Asymmetry of light reflecting points  ¢ Lobule position  ¢ Nostril-columellar relation  Psychological Chin position Alar base  assessment ¢ Vertical and horizontal position (in repose and smile)    ¢ Inter alar distance (should be 2 mm wider than intercanthal distance)  ¢ Insertion of the alar base    The lateral aspect of the nasal cavity is composed of three  anatomic structures: the inferior, middle, and superior turbi-  nates. The inferior turbinate forms a boundary of the internal  nasal valve, where its specially adapted erectile tissues regu-  late the air flow and facilitate heat and moisture exchange.   Branches of the anterior ethmoidal artery accompany the  external nasal branch of the anterior ethmoid nerve, passing  between the nasal bone and upper lateral cartilages, and supply  the soft tissues of the dorsum and tip of the nose. The posterior  ethmoidal branches supply the smaller area above the superior  concha on the lateral wall and a corresponding area high on the  septum [8]. The posterior part of the internal nose is supplied  by branches of the sphenopalatine ganglion of the second divi-  sion of the trigeminal nerve (the long sphenopalatine, the naso-  palatine and part of the greater palatine nerves).    Clinical examination should be comprehensive and include  the assessment of systemic diseases (Box 38.2) [9].   General examination would include ruling out any syn-  dromic deformities [9]. Obtaining correct history of systemic  disease and bleeding disorders are of paramount importance.  The extensive vascular network in the nose, in the presence  of a coagulation disorder, may predispose the patient to  severe haemorrhage in the intra- or post-operative period.   Existing breathing difficulty or any allergy-related symp-  toms such as rhinorrhea, sneezing, watery eyes, itching and  loss of sense of smell and taste are observed. Majority of  successful rhinoplasties are reductive in nature; an unde-  tected or uncorrected underlying airway compromise may  cause further deterioration and convert an aesthetic concern  to a functional predicament. If the presence of any sinus    infections and headaches is not recorded preoperatively, the  patient may attribute these conditions to rhinoplasty [10].    38.3.1 Examination of the Face  The face in the frontal view is divided into thirds and fifths for    assessment of proportion and harmony of various structures  (Fig. 38.1 1a, b, c). In the upper third, the intercanthal distance    and interpupillary distance is important in assessing the nasal  bones, dorsum and radix. For a proper facial balance, the  malar bone, maxilla, mandible and the nasal bones should be  in an optimum spatial relationship. The length of the upper  lip, its position during rest and smile, upper incisor show and  its proportion in relation to the rest of the face are also  assessed. The nose and chin may have a paradoxical relation-  ship whereby a patient may have an overprojected nose and at  the same time an underprojected chin and vice versa.    Fig. 38.11 (a)—(c) Examination of face and nose; frontal, lateral, basal. (b1) Ni - Ideal nasion, Ti Ideal tip. (b2) STB - Supra Tip Break, CLA -  Columella Labial Angle. (b3) Nasal Length is measured from nasal radix to nasal tip (A—B), Nasal projection (C—B) is length from Naso-labial  junction to nasal tip. The ratio between AB and CB (Goode’s Ratio) should be ideally 0.55 to 0.60    Visual analysis of the nose along with careful palpation  allows the surgeon to assess the morphology and thickness of  the skin and soft tissue envelope.   Frontal, profile and basal views should be used to  assess the various components of the nose discussed  above, individually.    Patient’s photographs are an important component of preop-  erative analysis and planning of the procedure. In addition,  pre- and post-operative photographs are crucial for outcome  monitoring and are indispensable from a medicolegal point  of view [11]. With the advent of 3D imaging, image fusion  and photogrammetry, preoperative and postoperative fea-  tures can be compared in all dimensions [12].   There are four important photographic views that are used  for analysis of the nose, namely, frontal, basal, lateral (at rest  and smiling) and oblique views (Fig. 38.12). Photographs    are standardised in relation to the Frankfurt horizontal plane.  All four views are evaluated for the assessment of the facial  horizontal thirds and vertical fifths. The quality of skin  (thickness and Fitzpatrick type) and facial symmetry are also  studied using all the views. The basic focus lies in the study  of the loco-regional anatomy and the inter-relationships of  the structures. The pictures are evaluated to assess any dis-  crepancies in size, deviations or dorsal hump that may be  immediately evident and recordable.    ¢ Frontal view  The length, width and the tip characteristics are well  observed on the frontal views. The width is individually  assessed in the upper, middle and lower thirds of the nose.  Frontal views also show a straight or a crooked nose. The  presence of a dorsal hump or a saddle deformity is noted as  these may provide an illusion of the nose being narrow or  wide, respectively. The presence of a truly wide nose may  also demonstrate features of pseudo/true hypertelorism.  The dorsal aesthetic lines should be studied in detail.  They follow the eyebrows across the radix and along the  dorsum to end at the tip defining points on either side.    The lines should be almost parallel with a smooth diver-  gence at the brow but without any visible or perceptible  breaks.   The nasal tip is assessed for symmetry and definition.  The tip is also assessed for features of boxy appearance,  bulbosity or bifidity. The alar base, ala and columella are  also evaluated. The formation of a gentle “gull in flight”  form should be appreciated for the relationship of the ala  and the infratip lobule. An exaggerated curve may be  indicative of a retracted ala or a plunging lobule. The  position and insertion of both ala and their symmetry and  direction are also noted.   Assessment should include the study of lobule, columella,  ala and the alar base. Emphasis should be placed on the  evaluation of the triangular shape of the nasal base, sym-  metry and the ratios, namely, the columella/lobule ratio  and the lobule to ala ratios. The nasal base should present  as an isosceles triangle with a rounded apex. The alar side-  walls should demonstrate a gentle flare. Poor triangular  form or a trapezoidal form is indicative of a broad dome.  Nostril symmetry and the angulations are studied next.  The nostrils are angulated at 30—45° to the midline and are  pear shaped. The caudal septum is assessed for straight-  ness and its position in relation to the maxillary crest and  anterior nasal spine. The alar base width, flare and inser-  tions are also assessed in this view.   Key points that need to be evaluated from the lateral view  include (1) a dorsal profile that may demonstrate a saddle/  hump and the supratip break, (2) evaluation of the chin  and mentolabial sulcus, (3) projection and rotation of the  nasal tip, (4) nasal length, (5) assessment of the radix and  (6) columellar show with double break.   The ratio of nasal projection is evaluated by the method  of Goode. The ideal ratio between the line joining the tip  defining point and alar-facial groove tangent, to the line  dropped from the nasion to the alar facial groove should  be between 0.55 and 0.60. Rotation of the nasal tip is  approximately considered 90° in Caucasian males and  between 90 and 95° in Caucasian females.   The length of the nose is relative to the person’s facial  profile and general stature. It may be categorized as the  central nose length from the nasion to the nasal tip and  lateral length from the nasion to the alar rims. A short or  long lateral length may reflect as retracted or hooded ala,  respectively. The nose may also show a relative increase  or decrease in length depending on the depth of the radix.  A deep radix may make the nose look short while a shal-  low radix makes the nose appear long.    The columella is also assessed for over- and undervisi-  bility with the evaluation of a columellar double break  that is formed by the junction of the medial and interme-  diate crus.    ¢ Oblique view assesses the volume of the tip lobule and  Brow tip aesthetic line.  Assessment of the oblique view may not provide objec-  tive details. However, the nose is most viewed at this  angle thus making it an important view to assess the aes-  thetic balance of the face and nose. Important features  that need to be assessed in this view include soft tissue  facets, lateral aspect of the nasal bones, nasal length, dor-  sal contour and tip projection.    ¢ Inspection with speculum will demonstrate any septal  curvatures, angulations or spurs.   e Endoscopy of the middle meatus should be done to rule  out clinical evidence of sinus disease.   ¢ Tests for functions of internal nasal and external nasal  valves should be done. Careful observation of the nasal  valves while the patient is asked to inspire will provide a  significant amount of information. A speculum or Q tip  facilitates proper examination. Cottle’s Maneuver helps  in localizing obstruction due to nasal valve dysfunction.   e Acoustic rhinometry is a recently developed objective  technique for assessment of geometry of the nasal cavity.  The technique is based on the analysis of sound waves  reflected from the nasal cavities. It measures cross-  sectional areas and nasal volume.   ¢ Rhinomanometry has also been widely accepted and  used as an objective method to assess nasal patency.  However, these tools may not necessarily show clinical  correlation [13].    Rhinoplastic approaches: (1) open approach or the open  structure rhinoplasty approach and (2) closed or the endona-  sal approach.   Open approach involves an external cutaneous incision  while the closed approach involves intranasal incisions only  (Fig. 38.13a, b).    Choice of incision is based on the clinical problem to be  corrected and the exposure required. The ideal incision must  enable adequate and easy access to the nasal architecture  without compromising the nasal structures. The differences  between the different types of incisions are highlighted in  Table 38.1.    The open structure approach is employed when exten-  sive reconstruction is required. There is more emphasis on  the preservation and realignment of structures of the lower  third of the nose and also achieving balance of the nasal  “tripod”.   The open approach involves the use of a marginal and  mid-columellar incision (Fig. 38.14b)    ¢ Marginal incision  e The incision is placed along the caudal margins of the  LLC, starting at the caudal margin of the medial crus, run-  ning along the entire dome and extended laterally along  the caudal margin of the lateral crus.  ¢ Columellar incision  e This is a transverse mid-columellar incision extending  across to connect the marginal incisions on either side.  Numerous modifications of the columellar incision have  evolved over a long period (Fig. 38. 15a, b, c).  — Rethi transcolumellar incision 1931 (across the apex  of the nostril aperture)  — Sercer “nasal decortication” approach—1957  — Bardach columellar base incision extending into prola-  bium (reserved for cleft rhinoplasty)    1. Nondelivery approaches are employed when minimal  reduction of the lateral crus or mild cephalic rotation of  the tip complex is indicated.   The technique in turn may involve either the cartilage  splitting approach or the retrograde eversion approach.    ¢ The cartilage splitting method involves a_ trans-  cartilaginous incision through the most cephalic portion  of the lower lateral cartilage that needs to be resected.  However, extreme care is taken to preserve at least 8 mm  of sound LLC to prevent structural compromise.   e The retrograde eversion method is difficult for beginners  and hence not favoured in current practise, and most sur-  geons today prefer to use the delivery method.    2. The technique for the delivery method encompasses two  incisions: the first inter-cartilaginous incision and the  subsequent marginal incision to mark the chondrocutane-  ous unit of the LLC. The nonvestibular side of the LLC is    Fig. 38.14 Incisions for  rhinoplasty: (a) closed and (b) a  open approach (MC- mid  columellar, M- Marginal)    then dissected off the overlying SSTE permitting the  delivery of the LLC chondrocutaneous unit as a bipedi-  cled flap. Improperly positioned intercartilaginous inci-  sion may predispose to scarring at the valve area.   Lateral nasal vestibular incisions for access to the parana-  sal premaxillary area   Endonasal transmucosal medial osteotomy facilitated  high up in the nasal vault.    The endonasal approach is, however, unsuited for the  novice surgeon and does depend on the surgeon’s experience  and prior training in Rhinoplasty for optimal outcomes.    Reduction rhinoplasty can weaken the underlying nasal tip  framework with subsequent buckling and late structural  deformity. Cartilage grafting during primary and revision    procedures helps to prevent such a secondary deformity  [14-17]. An open technique is preferred as it offers better  visualization for placement of grafts. The grafts used in rhi-  noplasty can be summarised as follows (Fig. 38.17a, b)  (Tables 38.2 and 38.3):    38.4.3.1 Deformities of Nasal Septum  Deformities of the nasal septum may either be congenital or  acquired. They are classified as shown in Box 38.4.   Septal deformities depend on alterations in the growth  and direction of growth of the septal cartilage.    Deformities of the nasal septum may present clinically  (Fig. 38.18a, b).   . Lateral angulation of the septum is seen as a bent nose    Fig. 38.17 Sources of cartilage graft; (a) septal cartilage graft (al) anatomy of septum (a2) marking for cartilage harvest preserving L shaped  dorsal strut (a3) incision for cartilage harvest (a4) harvested cartilage (a5) carving of harvested cartilage and (b) Harvest of auricular cartilage;  (b)- marking on the ear (b2)- incision (b3)- reflection of sub perichondrial flap to expose cartilage (b4) cartilage harvest (b5) closure of donor  site    Autogenous grafts—Donor site morbidity, increased operating time, predictable long-term results, minimal risk for extrusion and infection  Nasal septal cartilage Considered to the best grafting material as it is easy to harvest and contour  Intrinsic anatomy of septal cartilage [firmness, resiliency, flatness] provides optimal aesthetic results  Sufficient rigidity to provide structural support  No donor site morbidity with excellent long-term results  Insufficient when large volumes are needed/previous septal surgery  Auricular/conchal cartilage Easy to harvest but difficult to contour due to its brittle nature  Low strength and hence provides poor structural support  Low donor site morbidity and with good long-term results  Intrinsic anatomy [curved shape with elastic memory] of auricular cartilage makes it difficult to provide  optimal aesthetic results  Used if nasal septal cartilage is not adequate e.g. extensive revision cases and simultaneous multiple grafting  procedures  Useful when elasticity is needed e.g. lateral crus reconstruction  Insufficient when large volumes are needed  Costochondral grafts Abundant supply  Sufficient rigidity to provide structural support  Can be reharvested  Temporalis fascia Used for cartilage-fascia grafts in primary and revision rhinoplasty. For smoothening contour defects and  irregularities on the nasal dorsum.  Easy to harvest  Adequate size available  Shows minimal resorption and is stable in followup  Perichondrium over rib Used for repair of septal perforations and for smoothening irregularities over the dorsum  Easily available and harvested contiguous with rib cartilage which is a commonly used graft in rhinoplasty    Alloplastic grafts—No donor site morbidity, reduced operating time, unpredictable long-term results and increased risk of extrusion and  infection  Silicone Pliable, elastic solid that causes little tissue reaction  Easy to handle, comes in prefabricated shapes—most commonly used alloplastic graft material  Increased risk of displacement/extrusion as its nonporous nature prevents surrounding tissue in-growth,  instead, leading to the formation of a fibrous capsule  Easy to remove even after a long time as a fibrous capsule will form around the implant, without ingrowth  in to the graft  Asymmetric contracture of the capsule around the implant can deform the implant over time  Low strength and hence provides poor structural support  Preferred in Asians with thicker dorsal nasal skin  Medpor [high density Easy to carve and bend due to thermoplastic property  polyethylene] Poor aesthetic results and comfort due to its stiffness  Sufficient rigidity to provide structural support  Minimal risk for displacement due to its porous nature with subsequent ingrowth of surrounding  fibrovascular tissue  Difficult to remove in the long term as there will be extensive tissue ingrowth  Tends to shed particles, when implanted in stress-bearing and mobile areas may cause a chronic  inflammatory response  Gore-tex [expanded poly-tetra- | Porous implant composed of carbon and fluorine molecules with pores  fluoro-ethylene (PTFE)] Second most widely used alloplastic implant, after silicone  Better comfort and aesthetics due to its softness  Minimal risk for displacement due to its porous nature with subsequent ingrowth of surrounding fibro-  vascular tissue  Poor long-term aesthetics as it decreases in volume over time  Difficult to remove in long term owing to extensive tissue ingrowth  Low strength and hence provides poor structural support  Injectable filler materials—No donor site morbidity; reduced operating time; unpredictable long-term results and increased risk of extrusion,  infection and embolization  Bovine collagen, human-derived Mainly used for minor augmentations  collagen, hydroxyapatite Necessary to overaugment by 20-30% to compensate for long-term absorption  microspheres, hyaluronic acid Provides poor structural support  High complication rate including persistent redness, contour irregularity, swelling and necrosis of  surrounding dermis or soft tissue, hypersensitivity reactions, extrusion  Patients may object on religious grounds    The sequence to be followed for planning a proper sep-  toplasty includes   3. Internal examination should include (1) anterior  rhinoscopy and (2) nasendoscopy   4. Imaging of the nose, septum and the paranasal  sinuses is mandatory. This should include CT  scans with both soft tissue and bony windows  [18].   7. Informed consents to be obtained for the harvest  and use of grafts (Septum, Concha or Rib  cartilage)   8. Care should be exercised to preserve the integrity of  the turbinates and the internal nasal valve.    38.4.3.3 Surgical Approaches  Septoplasty may be performed in conjunction with a formal  rhinoplasty using an open or closed approach.    1. Endonasal caudal vestibular access via a right or a left  hemi-transfixion incision or  2. Bilateral septal transfixion incision [19, 20].   The local anaesthetic solution is infiltrated with adrenaline  for optimal haemostasis. This not only provides a clear field  for surgery but also aids in developing planes by the process  of hydrodissection. An incision is made at the caudal margin  of the septal cartilage, which may be unilateral or bilateral.  Cautious, careful, unhurried dissection in the correct ana-  tomical plane is done, using sharp precise instrumentation  (Cottle/Masing, Freer or Joseph’s elevator). It is imperative  to identify and stay in a bloodless sub-mucoperichondrial  plane. The light blue colour of the septal cartilage ensures  the correct plane of dissection. An anterior tunnel is first  made, followed by an inferior tunnel to expose the entire sep-  tum. The plane is then expanded and separated further with a  Killian forceps. This offers bilateral exposure of the dis-  sected tunnel and the septum. Sharp curvatures, angles and  fracture lines are negotiated carefully also bearing in mind  that the transition zone between the mucoperichondrium and  the mucoperiosteum is an area vulnerable to tears. Tears over  the mucoperichondrium require careful repair with vicryl  sutures on a round body needle. However, tears in the infe-  rior tunnel overlying bone need not be sutured and may act  as drains. The flap elevation is extended posterior to chon-  drovomerine and chondroethmoid junctions for complete  exposure of the bony septum.   Bony spurs or angulations and bends are identified, which  may contribute to airway block. The osteocartilaginous junc-  tion is then separated to free the septum in the posterior aspect.  Takayashu forceps are used to nibble away any bony/cartilage  spurs. This may also be performed using thin chisels and  osteotomes. Buckling of the septum may be corrected by  resection of overhanging cartilage in the caudal aspect.  Adequate relief thus allows the passive return of the septum to  midline. Measures such as scoring, suturing or the use of PDS  sheets/cartilage grafts may be required to correct and straighten  residual curvatures. Harvest of septal cartilage may be per-  formed at this juncture and should be done posterior to the key  area (imaginary vertical line joining the tip of the nasal bone  and the anterior nasal spine). Stabilisation to the midline is  achieved by the use of a PDS suture anchoring the dissected  septum to the anterior nasal spine. The flaps are reapposed  with one or two transfixion sutures to prevent septal haema-  toma. Nasal packing is outdated and has been replaced by  silastic sheets and intra-operative control with Merocel packs.    1. Minimal trauma to local tissues  2. Reduced post-surgical oedema and  3. A-faster-recovery-to-normalcy   2. Limited exposure & visualisation (headlight required)  3. Limited visualisation for the assistant    Nasal osteotomies are often required during correction of  deformities of the nose as well as an adjunct to procedures  which involve correction of the osseocartilaginous vault.    Fig. 38.19 Septoplasty intra-operative steps. (a) the part of the septum anterior to the line dropped from the tip of nasal bone (NB) to the anterior  nasal spine (ANS) has tobe preserved. (b) Dysjunction of the cartilaginous septum from the bony septum. (c) Septal repositioning with sutures to   2. Correction of a deviated bony nasal vault (crooked nose/  bent nose)    Different types of nasal osteotomies (Fig. 38.20a, b) are  utilised for a variety of clinical indications [21, 22]. They are  enumerated in Box 38.5.    ¢ Chisels/Osteotomes  Straight osteotomes—2 mm microosteotome  Curved osteotomes  Guarded osteotomes—Nievert, Silver  Angled blade osteotomes—Murray-Parkes  Notched osteotomes—Walter  ¢ Power instruments   The different techniques for performing nasal osteotomies are  (1) endonasal, (2) percutaneous, (3) endoral and (4)   The percutaneous technique involves the completion of a lat-  eral osteotomy and a transverse root(superior) osteotomy.  The local anaesthetic solution is infiltrated with adrenaline  10-15 min earlier for good haemostasis.   The sites of the lateral and superior osteotomies are  marked on the skin. The cephalic end of the cross-over of  these two osteotomies should be kept no higher than the level  of the intercanthal line.   A small 2-3 mm stab incision is made on the skin at the  middle of the lateral osteotomy marking. The incision is  deepened down and to bone. The osteotome is swept along  the entire length of the marking to provide good release of  the skin and subcutaneous tissue and keep the angular artery  away from the line of osteotomy. The osteotome is then  positioned supraperiosteally at 2 mm intervals and struck  with a mallet to produce an interrupted line of punch holes.  The osteotomies are started at the pyriform rim and contin-  ued superiorly to the nasofrontal junction. The same tech-  nique is followed for the transverse root(superior) osteotomy.  The contra-lateral nasal wall is osteotomised in a similar    Fig. 38.21 Steps in nasal  osteotomy. (a) Start of the  lateral osteotomy. (b)  Osteotomy marking on skull.  (c) Movement of the  osteotome for lateral  osteotomy    The dorsal hump is the most common problem for which  a patient may seek rhinoplasty. Based on the anatomical  units involved, three main types of dorsal hump may be  identified [23, 24];   2. cartilaginous hump that involves the cartilaginous middle  vault with septal and upper lateral cartilages and   3. the osseocartilagenous hump that is a combination of the  two.    38.5.1.1 Types of Dorsal Humps  Dorsal humps can also be categorised as true and pseudo-  humps. True humps may occur isolated or may occur in con-    junction with other nasal deformities. The pseudohump may  produce a relative appearance of a dorsal hump, while in  reality, the appearance may be due to a high anterior septal  angle, supratip prominence or tip ptosis (Box 38.6).    Bony hump removal (Fig. 38.23A—K)  En-bloc bony or cartilaginous hump removal requires expe-  rience as there is a high risk of excessive reduction when the  surgeon may be inexperienced. The procedure begins with  infiltration of lidocaine 2% with 1 in 100,000 adrenaline.   After exposure of the osteocartilaginous vault is completed,  the osteotome is engaged at the caudal edge of the nasal hump  (osteocartilaginous junction) and the bone is removed using an  osteotome and mallet (18 oz Heath mallet) with firm blows to  follow a careful alignment. It is better to always under-reduce,  rather than over-reduce as it may cause severely compromised  results. The dorsal edges can then be rasped down to the  desired extent. Care is taken not to rasp the cartilage as it may  produce irregularities, tears or avulsions.   When separation of a large hump is desired, placement of  a superior stop-cut as described by Tardy allows precise and  clear separation at the desired level. Diamond rasps are used  to smooth irregularities at the dorsal edge of the nasal bones.  Removal of an osteocartilagenous hump results in an open  roof deformity of the nasal dorsum, which needs to be closed  with an osteotomy [23].    carbide rasps (Rees)  ¢ Pull rasp/push rasp (Daniel)  ¢ Diamond rasps  Power saw  ¢ Rhinobur (Toriumi)  ¢ Piezoelectric saw    A saddle nose deformity is defined as a wide and flat nose  with a concavity on the nasal dorsum.  Classical clinical presenting features of this deformity are    ¢ Loss of height of the nasal dorsum (appearance of a short-  ened nose)    38.5.2.1_ Classification  Saddle nose deformity can be classified based on the under-  lying structural problem into    Fig. 38.22 Dorsal hump - clinical presentation. (a) Profile and (b) frontal pictures of patient 1. (c) Profile and (d) frontal pictures of patient 2    1. Bony saddle The causes responsible for saddle nose deformity are  2. Cartilaginous saddle many, namely, septal hematoma following trauma, iatro-  3. Combination of bony and cartilaginous elements genic—inappropriate surgery to the septum, bony vault &    Fig. 38.23 Hump reduction technique: Armamentarium (A, B & C). Surgical technique (D, E & F) Removal of the dorsal hump with the osteo-  tome, (G—K) Preparation of the “open roof” deformity for closure    middle vault and substance abuse (cocaine), diseases like  congenital syphilis/leprosy and racial predisposition—  African, Afro-American, and Asian.   with saddle nose deformity are enumerated in Box 38.8.  The septum may exhibit deformity with twisting/defi-   Surgery for the correction of saddle nose deformity may be  planned in a staged manner with the first stage involving the  correction of the foundation of the nose and the second stage  involving the aesthetic makeover [25, 26]. The aim of the pro-  cedure is to re-establish the tension between the nasal tip   ¢ Epicanthal folds due to the lateral movement of dor-  sal skin   e Relative increase of the upper lip length (columellar  skin migrates downward)    complex and the dorsum, which has been lost due to the con-  certina effect.   Surgical correction involves three essential steps that are  independent of each other.    e Establish the height and length of the septum to restore  structural support to the entire nose. This involves the use  of a robust septal extension graft, fashioned from har-  vested rib cartilage (preferably the eighth rib).   e Correction of the dorsal deficiency using a dorsal strut  graft that extends from nasion to under the domes.   e Provision of support for the tip complex. This is achieved  with the use of a columellar strut graft to restore tip  projection.    This procedure involves the use of strong and robust car-  tilage grafts. The eighth rib provides an adequate amount of  cartilage which is ideal for this situation. Ear cartilage lacks  rigidity, while banked cartilage tends to undergo  resorption.    38.5.3 Correction of the Deviated Nose  Deviated noses can be of two types    1. “Bent” nose where the nasal bones and the upper lateral  cartilages point to the same side, and   2. Post trauma to the face and nose—following road traffic  accidents, sports injuries or interpersonal violence   3. Iatrogenic—as a result of earlier surgical procedures;  Maxillary impaction by a LeFort 1 osteotomy without  addressing the septum or septoplasty with excessive scor-  ing, resection and weakening    Fig. 38.25 Saddle nose-intra op. (a) intra-operative pictures demonstrating use of rib cartilage for dorsal nasal reconstruction. (b) Landmarks for    38.5.3.2 Clinical Features  Clinical features of a deviated, bent or crooked nose include  both functional and aesthetic issues    1. Blockage of the nasal airway, unilateral or bilateral  2. Visible deformities affecting the upper, middle and lower  thirds of the nose  (a) Frontal  e Deformity of the nasal pyramid  e Twisting or angulation of the nose  ¢ Constriction or bulge at the middle vault  e Bending of the nose showing midline  discrepancy  e Unequal height of the nasal bones  e Tip deformity secondary to the loss of septal sup-  port/angulation  (b) Profile  e Patient may present with a dorsal hump or a saddle  deformity  ¢ Loss of tip projection  e Nasal tip ptosis  ¢ Retraction of the columella    (c) Basal  e Deviation of the nasal tip or middle vault  e Angulation or shortening of columella  e Displacement of the caudal septum from the max-  illary crest into the nasal vestibule  e Nasal valve obstructions  (d) Varied presentations of septal deformities (Mladini  classification)   Septorhinoplasty is required to correct the deformity. Some  prefer single-stage correction, while others may choose  staged procedures (first stage septoplasty followed by a sec-  ond stage external deformity correction). However, a single-  stage correction is preferred. This is usually performed using  an open structure approach with exposure and separation of  the septum from the upper lateral cartilages. Straightening of  the septal cartilage is performed by excision and/or partial  division of the cartilage and may be followed by scoring or  sutures as indicated. Some surgeons prefer the use of a PDS  sheet to splint the corrected septum. However, costal carti-  lage may be harvested for reinforcement of the straightening    Fig. 38.26 Techniques of reduction of crooked nose deformity with twisting/angulation of septum, (a) differential reduction of hump prior to  ostetotomy, (b) septal repositioning, (c) digital reduction/manipulation after osteotomy, (d) line diagram of “low-to-low” osteotomy, (e) intra-  operative picture with osteotome positioning (low-to-low), (f) line diagram of “nasal bone osteotomy’’, (g) intra-operative picture with osteotome  positioning (nasal bone osteotomy)    and to provide a spreader effect to correct the nasal valve  simultaneously. Osteotomy of the nasal bones is often  required to correct the angular deformity of the bony vault. A  tip plasty may be necessary in most cases to correct the nasal  tip tripod deformity secondary to nasal deviation.   It is to be borne in mind that the results for the correction  of deviated noses are not always satisfactory. There is a pos-  sibility of residual deformity, recurrent deformity, loss of tip  support and saddling.    The nasal tip is the centre of focus for both nasal anatomy  and aesthetics. It is a very important anatomical subunit and  can be most challenging to refine surgically.   Nasal tip deformities may show varied morphology and  diverse clinical presentations (Fig. 38.27a—f). They may  occur in isolation or concomitant with deformities of the dor-  sum or septum.    Fig. 38.27 Types of tip deformity. (a) Wide bulbous tip, (b) ball-ended amorphous tip, (c) plunging infra-tip lobule, (d) amorphous bulbous tip  with deviation and constriction of right lower middle vault, (e) over-projection of nasal tip owing to prominent ANS & overtly long lower lateral  cartilage with normal naso-labial angle, and (f) nasal tip over-projection with upward over-rotation    Tip deformities can be enumerated as follows as in Box  38.9.    38.5.4.1 Wide Nasal Tip  A tip is considered abnormally wide when the width of the  tip is greater than the width of the dorsum. Normally, the tip  width is equal to the width of the dorsum.   A wide nasal tip may be caused due to three morphologi-  cal alterations:   Surgery for the nasal tip can be performed either through a  closed or open structure rhinoplasty approach. This may  depend on the clinical indications involved as well as the  skill and experience of the operating surgeon. Steps for cor-  rection of a wide nasal tip include reduction of the inter-  domal width by placing a permanent interdomal suture  with 5-0 prolene or 5-0 PDS (semipermanent). This is fol-  lowed by the creation of a new domal angle (transdomal  suture followed by the interdomal suture). One should also  consider surgical removal/excision of a segment of the  intermediate crus for better tip definition (Fig. 38.28a, b).   Bulbous tips have problems associated with thick SSTE  (skin & soft tissue envelope), excessive subcutaneous fat,  strong convex and bulky lateral crura and a concertina effect  of a shortened nose in general.    Surgical management  This involves careful degloving of the SSTE leaving the subcu-  taneous fibrofatty tissue on the lateral crura. Careful defatten-  ing and thinning of the subcutaneous plane should be  performed. A modest cephalic trim is performed to correct the  large and bulky lateral crura. As this is a more general defor-  mity involving not only the tip but also the associated SSTE, a  careful distribution of volume to produce balance may be  required. This helps camouflage the deformity to a great extent  while improving outcomes.   Excessive or injudicious defattening of the nasal tip  may cause ischemia/necrosis of the skin of the nasal tip,    blanching of the tip skin with exposure to cold, contour  irregularities of the underlying cartilage to become visible  and may also lead to the skin pores communicating to the  underlying tissues.    38.5.4.3  Overprojected Nasal Tip (Fig. 38.30a—c)  Nasal projection is defined as the distance along a perpen-  dicular line from the vertical facial plane to the anterior most  point on the nasal tip. The nose when not in normal facial  balance can either be overprojected or underprojected.   The key to correction of the overprojected nasal tip is to  establish the cause. This may be due to the increased length    Fig. 38.30 Overprojected nasal tip  (a) profile of patient 1, (b) profile  of paitent 2 at repose and (c) profile  of patient 2, smiling    of the anterior nasal spine, excess caudal septal height or  overtly long alar cartilages.   Surgery for the overprojected nose should be performed  through a full bilateral septal transfixion incision with the  aim of deprojecting the nose by 4—5 mm. The anterior nasal  spine is reduced judiciously followed by the resuspension of  the upper lip to the ANS. The anterior septal angle is low-  ered to achieve further deprojection. Deformities of the alar  cartilage may be varied and may require division and over-  lap of the medial crura, division or resection of the medial  footplates. A lateral crural overlap with resection of a seg-  ment is performed 1 cm from the dome. Domal resections  are to be avoided as they may produce secondary deformi-  ties: irregularities, angulation, and bossa formation. They  may produce a sharp angulation with a pointed tip (pinched  nose), which may require a shield graft for tip camouflage.  Care should be taken to avoid/prevent loss of tip support  during these manoeuvres.    38.5.4.4 Underprojected Tip (Fig. 38.31a, b)  It is important to establish the cause for underprojection  prior to treatment. Causes of underprojection may include    e Deficient or absent anterior nasal spine/premaxilla  e Bilateral cleft lip nose   Surgery for the underprojected nose should follow the  sequence provided below: the columella is strengthened with  a strut graft, a transdomal suture is placed to project the dome.  A shield, cap or an umbrella graft may be used to increase tip  projection. A caudal septal extension graft is added to  strengthen the septal support and increase projection. Finally,  a transcolumellar suture is performed through the medial  foot-plates. In patients with the deficiency of the premaxilla  or the total bony maxilla (cleft maxillary hypoplasia) where  loss of bone support contributes to the loss of nasal projec-  tion, advancement of the maxilla or Onlay grafting of the pre-  maxillary segment may offer the correct solutions.   (Fig. 38.32b)  Tip rotation denotes the angle formed by the columella to the  upper lip. The point of reference here is the nasolabial angle.  Deformities of the nasal tip related to the rotation can be  either over-rotation or under-rotation (ptotic nose).    Over-rotation of the nose may arise due to various  causes: post-traumatic (caudocephalic impact to the nose)  or an inherently short nose. Over-rotation may also be a  complication of prior rhinoplastic procedures due to over-  zealous caudal septal reduction, excessive cephalic trim of  the lateral crura or injudicious lowering of the anterior sep-  tal angle.   Surgery for the correction of over-rotation of the nasal tip  should include techniques for de-rotation of the nose like  placement of a caudal septal extension graft and/or extension  of the dorsal graft beyond the domes. These procedures require  extensive cartilage grafting to lengthen the shortened nose.   Under-rotation denotes cephalocaudal rotation of the nasal  tip, which makes the tip point downward. This needs to be  differentiated from an underprojected tip. However, occa-  sionally both problems may co-exist. It is also important to  identify the presence of pseudo-ptosis in which the tip is nor-  mal but a more prominent anterior septal angle makes the tip  appear ptotic.    Fig. 38.31 Underprojected tip. (a) Clinical picture and (b) diagrammatic representation    Ptotic tips need to be examined both at rest and dynami-  cally. The dynamic inferior movement of the nasal tip may  occur due to the downward pull of a strong depressor septi  muscle. Care should also be taken to look for any other asso-  ciated deformities.   Causes for an under-rotated or ptotic tip may be heredi-  tary as in the noses of people from the Mediterranean coun-  tries, developmental due to heavy SSTE and weak cartilages  or the presence of excessive skin in the membranous colu-  mella. Patients with bilateral cleft lip deformities are predis-  posed to have underprojected and under-rotated noses due to  columellar deficiency.   Iatrogenic causes for tip ptosis include: poorly planned  and executed septorhinoplasty with loss of septal support,  inadequate maintenance of tip support or reattachment of the  tip support structures. It may also be a complication follow-  ing (1) prolonged intubation with the nasotracheal tube not  anchored well and (2) tumour ablations with inadequate  reconstruction.    Surgical management  Correction of the ptotic tip should be based on the anatomy  involved. It is best to follow an algorithm for planning the    Fig. 38.32 Nasal tip  rotations clinical. (al, a2, a3)  Under-rotation of tip and (b1,  b2) Over-rotation of tip    surgical procedure. The structures contributing will enable  us to plan and perform the correct procedure.    ¢ An elongated septum producing the ptosis is corrected by  a wedge excision of the excessive septum and the overly-  ing mucosa (Fred technique).   ¢ Elongated lower lateral cartilages can be managed by two  methods depending on the tip projection; in underprojected  tips, a columellar strut is provided for enhancing support  and augmented with the tip rotation suture, while in the case  of an overprojected tip, transection of the LLC is performed  with overlapping and suturing. The tip rotation suture may  be optional depending on the clinical indication.   e In the case of a shortened medial crura, a columellar strut  or a medial crural anchor suture is placed with the tip  rotation suture again being optional.    The normal width of the ala falls within or just beyond an  imaginary vertical line dropped from the medial canthus to  the upper lip. The ala may be either narrow or wide. A wide    ala compromises facial aesthetics and is often a complaint  for which the patient seeks help.   A wide alar base may be a characteristic of racial variations,  for example, African and Asian races exhibit increased width  of the alar base. It may also be wide in patients with congeni-  tal anomalies like cleft lip and palate. Wide alar base may  also be due to iatrogenic causes like    1. after a Le Fort 1 maxillary advancement or impaction  surgery,   2. injudicious rhinoplasty with loss of tip projection due to  loss of septal support   Patients with a wide alar base exhibit a nose that looks flat  and broad; the alar columellar line may be straight and they  may have an associated wide nasal tip. In the basal view,  the nose presents with reduced tip projection and short or  distorted columella. The alar side walls show increased  bulk and increased flare, and the alar insertion into the  nasolabial area may be horizontal or oblique. The alar sill    Fig. 38.33 Wide ala surgery techniques. (a)  Traditional Weir excision (leaves a notch al  deformity) and (b) modified excision  incorporating a lateral advancement which  prevents notch deformity and restores  continuity of alar rim    width may also show an increase. The premaxillary base  that supports the alar complex may be normal, deficient or  asymmetric.   The nose should be evaluated for the cause of alar widening.  This is the basis on which the treatment may be planned.  When there is a doubt regarding the width of the ala, it may be  wise to abandon the idea during a primary rhinoplasty and per-  form the alar correction as an isolated secondary procedure.    38.5.5.4 Surgical Treatment (Fig. 38.33a, b)  Surgery for the wide ala needs to be sequenced after assess-  ment of the cause; this may be a wide ala demonstrating   . presence of a lateral insertion of ala on the face.    ¢ The treatment of choice for the flaring ala is wedge exci-  sion (Weir) (Fig. 38.34), which helps to preserve the natu-  ral contour of the ala as well as provide a good camouflage    of the scar. A medial flap excision technique as described  by Sheen may also be a good alternative to this. The deci-  sion regarding medial repositioning of the alar base  should be in accordance with Sheen, who recommends it  only in cases of extreme lateral divergence.   e When flaring is associated with a wide sill then a wedge  with a sill excision may be preferred to correct the defor-  mity. In rare instances an isolated sill excision may be  indicated for a problem of increased sill width alone.   ¢ When the nose demonstrates a lateral insertion of the alar  base on to the face, then a “V to Y” plasty is performed as  described by Bernstein, which helps relocate the alar base  medially.    Septal perforations are pathological defects in the nasal sep-  tum which form communications between the right and the  left sides of the nasal cavity. These may present as anterior,  mid-septal or posterior perforations (Fig. 38.35a, b).    Fig. 38.35 Septal perforation; (a) clinical presentation, (b) intra-oper-  ative picture   The occurrence of septal perforations also leads to a variety  of sequelae that produce secondary deformities of not only  the nose but also significantly affect the face and the oral  structures. The nose may show a saddle deformity, columel-  lar retraction and narrowing of the nasal valve. Furthermore,  the loss of nasal cartilage and bony framework may lead to a  concertina deformity of the skin envelope. Perforations may  expand in an inferior direction with associated necrosis of  the vomer and maxillary crest, thus causing a palatal fistula.  Other symptoms include nasal airway block, nasal discharge,  crusting, epistaxis, midfacial pain, and a characteristic whis-  tling noise.   Investigations for perforations of the nasal septum include a  thorough clinical evaluation of the nasal cavity, oral cavity and  the face for accurate diagnosis. The patient is also subjected to  a rhinoscopy and a nasendoscopy for assessment of the intra-    nasal deformity. This is followed by a biopsy from the margins  of the perforation. A swab may also be performed for culture  and sensitivity when there are signs of acute infection of the  region.   Treatment is initiated in a conservative form with counselling,  wound care and topical medication. This involves abstinence  from cocaine use with rehabilitation under supervised care.  Regular inspection of the nasal cavity and nasal toileting with  seawater douches. Topical administration of Naseptin cream  alternating every 2 weeks with Bactroban (Mupirocin) oint-  ment is mandatory prior to surgical intervention.   Surgical management (Fig. 38.36a, b, c) for septal perfo-  rations is extremely challenging and often give disappointing  results. Any treatment is bound to be compromised due to  resurgence of the cocaine addiction and poor vascular status  of the involved anatomy resulting in a high incidence of  residual defects after surgery.   There are also risks of total failure of procedures with sec-  ondary donor site deformities, adding to the post-surgical  morbidity in these patients.    To understand the problems associated with the nasal valve,  it is important to see the distinction between the “nasal valve  area” or the internal nasal valve, the “nasal valve” and the  external nasal valve: The nasal valve area is the empty trian-  gular space that is bounded medially by the nasal septum,  laterally and superiorly by the caudal margin of the upper  lateral cartilage and its attachment to the pyriform rim and  inferiorly by the bony nasal floor. The nasal valve specifi-  cally denotes the slit that is seen between the caudal end of  the upper lateral cartilage and the nasal septum.  Physiologically, the internal nasal valve is the area offering    the highest resistance to airflow, and any deformities of this  region may compromise the air-flow dynamics.    The aetiology of nasal valve problems are enumerated in  Table 38.4.    Components of the external  nasal valve  ¢ Alar rim and alar side wall  ¢ Columella  * Caudal septal margin  ¢ Nasal sill   — Medialisation of the inferior  turbinate due to an injudicious  lateral osteotomy   ¢ Iatrogenic causes (knock-knee  deformity of the alar sidewall  due to excessive cephalic trim)   It is extremely important to identify the exact location of the   Sequencing of treatment for the management of nasal valve  problems should include certain empirical steps. The first  step is to perform an optimal septoplasty to relocate the sep-  tum to the midline. This is followed by straightening and  strengthening of the alar sidewall using alar batten grafts and  rim grafts. Narrowing of the columellar base may be per-  formed in cases of true columellar widening. Collapse of the  nasal valve can be corrected by the use of spreader grafts that  help in widening. In certain cases, there may be webbing or  scarring along the nasal valve area. This may need a “Z”  plasty for release and correction. Finally, judicious removal  of the inferior turbinate may be contemplated in indicated  patients after due consultation with the ENT surgeon.    A sequela may be defined as a natural consequence follow-  ing a disease process or a surgical procedure while a compli-  cation implies undesirable sequelae or process following  surgery.   This section with dwell on the common sequelae and  complications that may occur following rhinoplasty and will  help providing tips for reducing or preventing  complications.    Most sequelae are self-limiting and may not require any  active intervention. However, it is imperative to follow cer-  tain steps to minimise or avoid complications as discussed  below.   The key to minimising or preventing unfavourable out-  comes depends on proper case selection after a thorough  evaluation of the patient both physically and psychologically  (perceived complaint vs objective deformity). A good clini-  cal examination should follow with optimal documentation  (clinical analysis and photographs). The subsequent consul-  tation should include obtaining informed consent from the  patients after discussion of the indications and anticipated  complications associated with the surgical procedure. It is  important to understand our limitations and accept them  while not refraining from seeking professional help/support  when needed.   Complications in rhinoplasty may depend on the area of  surgery and the procedure performed as indicated below:    1. Complications associated with the nasal dorsum include  loss of dorsal height, concavity or saddle deformity (due  to over-resection), residual hump, supratip prominence or  a true “polly-beak” deformity due to under-resection.  There may be bony or cartilaginous irregularities (inade-  quate removal). An open roof deformity may present if  the nasal bones are not infractured after hump reduction.  An incomplete lateral osteotomy may result in a lateral  wall step deformity, while medialisation of the upper lat-  eral cartilages may result in an inverted “v” deformity.  Another complication is the appearance of a visible dor-  sal septal edge.   2. Complication of tip deformities may present as a “pinched  tip” or a “knock-knee” alar deformity (over-resection of  the lateral crus). It may also show tip changes like “‘button-  tip” deformity, tip/domal asymmetry, supra-alar concav-  ity or alar retraction. Loss of tip support produces ptosis  of the tip, loss of tip projection may produce infratip slip  below the anterior septal angle and excess resection of the  caudal septum may lead to over-rotation of the tip  complex.   3. Alar base reduction complications may include narrow-  ing of the nostril circumference, which may contribute to  increased nasal airway pressure. The surgery by itself  may cause a web scar at the alar-facial junction. It may  also result in distortion and secondary deformity of the  nose, cheek and lips.   4. Complications following septal surgery include failure to  straighten, midline deviation, tip deviation secondary to  caudal septal displacement and septal collapse leading to  a saddle nose deformity. The columella may develop  retraction or scarring and rarely necrosis.   The skin and soft tissue envelope may also show scar-  ring, ischemia/discolouration and at times telangiectasia.    Management of complications may be necessary when  the deformity is visible to both the surgeon and the patient.  This necessitates revision or secondary surgery which may  be indicated in about 5—8% of the patients. Even when  indicated, it is better to wait for a year prior to attempting  revisions or secondary interventions. This is to facilitate a  careful assessment of long-term changes following the pro-  cedure and the final outcome prior to intervention.    Rhinoplasty in most realms is considered as the epitome of  aesthetic surgical skill. This burdens the surgeon with the  responsibility of performing the surgery with accurate  planning and prediction of outcomes. It is also important  for both the young surgeon and the patient to understand  that the final outcome of the surgery is not in the immediate  future but is a culmination of all the surgical manoeuvres  and their response over a period of time. This is the same  fact that makes rhinoplasty among the most difficult to  master. Rhinoplasty has transgressed from the early proce-  dures of sole nasal reduction to encompassing not only the  aesthetics of the nasal complex but also improvement of the  function and establishing a balance for today’s patient. This  chapter is aimed to provide the reader with the basics of  surgical techniques. Perhaps, this is one surgical skill where  the surgeon still holds all the cards while the others are los-  ing the battle to technology.    1. Oneal RM, Beil RJ. Surgical anatomy of the nose. Clin Plast Surg.  2010;37(2):191-211.   2. Lessard ML, Daniel RK. Surgical anatomy of septorhinoplasty.  Arch Otolaryngol. 1985;111(1):25-9.   3. Gonzalez-Ulloa M, Castillo A, Stevens E, et al. Preliminary study  of the total restoration of the facial skin. Plast Reconstr Surg (1946).  1954;13(3):151-61.   4. Letourneau A, Daniel RK. Superficial musculoaponeurotic system  of the nose. Plast Reconstr Surg. 1988;82(1):48-57.   5. Wright WK. Surgery of the bony and cartilaginous dorsum.  Otolaryngol Clin North Am. 1975;8(3):575—98.   6. Pitanguy I. Surgical importance of a dermocartilaginous ligament  in bulbous noses. Plast Reconstr Surg. 1965;36:247-S3.   7. Guyuron B. Soft tissue functional anatomy of the nose. Aesthetic  Surg J. 2006;26(6):733-S.    8. Hollingshead WH, editor. Anatomy for surgeons, vol. 1. 3rd ed.  Philadelphia, PA: Harper and Row; 1982.   9. Khan HA. Rhinoplasty: initial consultation and examination. Oral  Maxillofac Surg Clin North Am. 2012;24(1):11-24. Review.   10. Patient assessment for Rhinoplasty. In: Guyuron B, editor.  Rhinoplasty. Edinburgh: Elsevier/Saunders; 2012.   11. Guyuron B. Precision rhinoplasty. Part I: The role of life-size pho-  tographs and soft tissue cephalometric analysis. Plast Reconstr  Surg. 1988;81(4):489-99.   12. Moscatiello F, Herrero J, Gonzélez Ballester MA, Carrefio  Hernandez E, Piombino P, Califano L. Preoperative digital  three-dimensional planning for rhinoplasty. Aesthet Plast Surg.  2010;34:232-8.   13. Andre RF, Vuyk HD, Ahmed A, Graamans K, Nolst Trenite  GJ. Correlation between subjective and objective evaluation of the  nasal airway. A systematic review of the highest level of evidence.  Clini Otolaryngol. 2009;34(6):5 18-25.   14. Sajjadian A, Naghshineh N, Rubinstein R. Current status of grafts  and implants in rhinoplasty: Part Il. Homologous grafts and allo-  genic implants. Plast Reconstr Surg. 2010;125(3):99e-109e.   15. Sajjadian A, Rubinstein R, Naghshineh N. Current status of  grafts and implants in rhinoplasty: Part I. Autologous grafts. Plast  Reconstr Surg. 2010;125(2):40-9.   16. Koehler J, McLain L. Grafting in cosmetic rhinoplasty. Oral  Maxillofac Surg Clin North Am. 2012;24(1):59-66.   17. Jang YJ, Moon BJ. State of the art in augmentation rhinoplasty:  implant or graft? Curr Opin Otolaryngol Head Neck Surg.  2012;20(4):280-6.   18. Wotman M, Kacker A. What are the indications for the use  of computed tomography before septoplasty? Laryngoscope.  2016;126(6):1268-70.   19. Shah J, Roxbury CR, Sindwani R. Techniques in septoplasty: tradi-  tional versus endoscopic approaches. Otolaryngol Clin North Am.  2018;51(5):909-17.   20. Most SP, Rudy SF. Septoplasty: basic and advanced techniques.  Facial Plast Surg Clin North Am. 2017;25(2):161-9.   21. VanKoevering KK, Rosko AJ, Moyer JS. Osteotomies demystified.  Facial Plast Surg Clin North Am. 2017;25(2):201-10.   22. Wayne I. Osteotomies in rhinoplasty surgery. Curr Opin Otolaryngol  Head Neck Surg. 2013;21(4):379-83.   23. Bohluli B, Moharamnejad N, Bayat M. Dorsal hump surgery and  lateral osteotomy. Oral Maxillofac Surg Clin North Am. 2012  Feb;24(1):75-86.   24. Barrett DM, Casanueva F, Wang T. Understanding approaches to  the dorsal hump. Facial Plast Surg. 2017;33(2):125-32.   25. Suh MK. Dorsal augmentation using autogenous tissues. Facial  Plast Surg Clin North Am. 2018;26(3):295-310.   26. Kim CH, Park SC. Homologous tissue for dorsal augmentation.  Facial Plast Surg Clin North Am. 2018;26(3):311-21.    Mladina R. The role of maxillar morphology in the development of  pathological septal deformities. Rhinology. 1987;25(3):199-205.    Open Access This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.  org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropri-  ate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.   The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in  a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.   The first successful demonstration of laser was performed by  Maiman in 1960 who also predicted one of its uses to be in  medical science [1, 2]. Decades after the first medical use in  the oral cavity and face, lasers are not just an adjunctive tool  today but are an integral part of an Oral and Maxillofacial  Surgeon’s (OMS) armamentarium. Although CO, laser has  been the traditional workhorse for an OMS, advancement in  the capabilities of CO, lasers, as well as the development of  other types of lasers, has helped grow their utility. Increasing  use of lasers in turn has created greater evidence of its effi-  cacy and safety record. Use of lasers has not only added  advantages to conventional OMS procedures, as opposed to  a scalpel, it has also given rise to newer procedures, which  were not possible with conventional tissue-cutting tools.    Modern lasers are simple to use but a lack of knowledge on  the physics of lasers, inadequate training and caution in han-  dling lasers, can give rise to potential adverse outcomes and  unwanted complications. The term “laser” stands for light  amplification by stimulated emission of radiation and was  first used by Gordon Gould in 1957 [3]. The laser, as opposed  to a regular light source, is composed of monochromatic,  coherent and collimated beams, which, when they strike a  suitable target, create photoacoustic, photochemical, pho-  toablative, and photothermal effects. Laser light energy can  undergo absorption, reflection, transmission, and scattering  based on the optical properties of the target tissue or matter.  For surgeons, the most desirable action is absorption into the   Department of Oral and Maxillofacial Surgery, Virginia  Commonwealth University Medical Center, Richmond, VA, USA  e-mail: srenapurkar @ vcu.edu; rastrauss @ vcu.edu    © The Association of Oral and Maxillofacial Surgeons of India 2021    tissue, which creates the predictable photothermal outcome  of coagulation and then vaporization of tissues [4].   The basic component of a laser unit includes a “laser cav-  ity” where the laser beam is produced via the phenomenon of  stimulated emission as postulated by Albert Einstein. The  laser cavity is composed of an active medium, an excitation  source acting as a pumping mechanism, and an optical reso-  nator (Fig. 39.1). The active medium is the chemical (gas/  liquid/solid) that the type of laser is named after and is the  material that undergoes stimulated emission. The photons of  energy produced are collimated and amplified to produce the  laser beam, which is then delivered to the target tissues via  an appropriate delivery mechanism, either a flexible fiberop-  tic system, semiflexible hollow waveguides, or articulated  mirrored arms (Fig. 39.2a—c). Lenses focus the active laser  beam to create a “focal point,” the point at which the energy  is condensed to the smallest area to create the maximum  effect. Some fiberoptic laser systems utilize a quartz or sap-  phire crystal at the tip of the fiber to enable the beam to be  absorbed by this crystal and allow contact with tissues at the  tip of the fiber, while others are used in a noncontact mode.  A laser beam is an electromagnetic beam of radiation, which  can fall anywhere in the spectrum of visible or invisible light.  Nd:YAG, CO,, and erbium lasers fall into the infrared invis-  ible spectrum; hence, they are often accompanied by a visi-  ble aiming beam, which helps the surgeon to know the point  in the tissues where laser beam hits the target tissues. Aiming  beams can be another low power laser or a regular light  source [4] (Fig. 39.3).   The factors related to the use of lasers that are under con-  trol of the surgeon include the spot size, power, and time on  target. The spot size of the laser is the width of the laser beam  on target. At the focal point, the maximum energy is focused  to produce the smallest spot size or the thinnest possible inci-  sion but to the greatest depth. When the tip of the laser deliv-  ery system is moved away from the tissues, the laser beam  diverges causing a bigger spot size and the energy is then  distributed over a larger area and the related depth is    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1-15-1346-6_39    Fig. 39.2 (a) Fiberoptic laser. (b) Hollow waveguide laser. (c) Articulated arm laser    decreased [5]. Laser emission modes and the surgeon’s hand  speed can affect the temperature rise and effect in the tissues.  Lasers can be emitted in “continuous-wave” mode or in a  “pulsed mode.” Lasers used in pulsed mode allow time for  tissues to cool before the next pulse of laser radiation is  started while continuous wave mode of laser must be stopped  manually to allow the tissues to cool. The time between  pulses can help avoid thermal effects on surrounding tissues  or excessive thermal effect on target tissues. The lasers with  pulsed mode of emission can be of two types, “gated pulsed”  or “true pulsed.” True-pulsed lasers are pulsed by a mecha-  nism within the laser cavity, while the gated-pulsed lasers  have a shutter-like mechanism outside the laser cavity [4].    Lasers have obvious advantages, which make them superior to  conventional cutting tools. An ability to provide better hemo-  stasis is a great advantage for surgeons to maintain visibility  and reduce blood loss. Since spot size, power, and time on    target are regulated by the surgeon, lasers provide better con-  trol of desired tissue changes, which enhances the precision of  surgery. Increased precision of the depth of tissue damage  along with fewer myofibroblasts in laser wounds compared to  scalpel wounds, allow for improved tissue healing and  decreased scarring. The mentioned advantages are presumed  to decrease postoperative pain with the use of lasers, although  the pathophysiology for this effect is not well understood.    Despite several advantages of lasers in surgery, the provider  should make sure the benefits outweigh the risks and disad-  vantages. Hard-tissue lasers such as Er:YAG and  Er:CR:YSGG do not match the speed of bone or tooth cut-  ting as do conventional tools such as burs or saws. Soft-tissue  healing after laser-assisted incision or excision is slower  (although with decreased scarring) than tissue healing using  scalpels. The associated learning curve and costs of the laser  equipment add to the drawbacks of using lasers.    The type of laser to be used is based on the laser’s physical  characteristics, interaction with the target tissues, and the  goals of the procedure. For example, CO, laser’s excellent  affinity for water, which is the main component of soft tis-  sues, makes it the most widely used laser for soft-tissue sur-  gical applications. The most commonly used CO, laser is the  10,600-nm wavelength, although 9600-nm and other wave-  length variants of this laser exist. The CO, laser is currently  the most ideal laser used for most intraoral and extraoral  soft-tissue procedures. The absorbed energy causes vapor-  ization of the intracellular fluid causing tissue vaporization,  while lateral heat conduction causes contraction of collagen  and closure of blood vessels of approximately 500 p or less  in diameter. High-power CO, lasers are generally delivered  via articulating arms, but new hollow waveguide systems  suitable for office use provide increased accessibility intra-  orally along with their ease of use [6, 7].   Other lasers include the Nd:YAG (a crystal of Ytrrium,  Aluminum, and Garnet doped with the rare earth element  Neodymium) laser, which functions in the near-infrared  electromagnetic spectrum at 1064 nm, and has minimal  water and superficial tissue absorption leading to deeper tis-  sue penetration. Hence, the Nd:YAG can be used for coagu-  lation of deeper and larger (2-3 mm) diameter vessels. These  qualities of Nd:YAG have led to its use in treating  angiomatous or vascular tissue lesions, although this same  lack of water absorption limits its utility for the  OMS. Depending on the desired effect, the Nd:YAG laser  can be used both in contact and noncontact modes [8-10].   The Er: YAG laser works at a 2940-nm wavelength and is  even more highly absorbed in water than the CO, laser lead-  ing to rapid absorption by the superficial layers of tissue and  minimal penetration. This can be an advantage in some cases  but also means that this laser is less effective on tissue than  the CO, laser. As an example, when used for cosmetic skin  resurfacing it shows much more superficial effects, which  heal quite quickly, but also shows much less of a result than  CO, laser does. For this reason, it has fallen somewhat out of  favor for this purpose [11-15]. Owing to limitation of its  thermal effects mostly in superficial layers of soft and hard  tissue, Er: YAG laser has become popular in implant den-  tistry. It can be used on both soft and hard tissues and finds  its application in bone preparation, second-stage surgery,  treatment of peri-implantitis. Being reflected off the surface,  it has minimal or no apparent adverse effects on dental  implants [16].   The Holmium: YAG laser is generated at a 2100-nm wave-  length, which enables it to be delivered in contact mode via  fiberoptic cable also demonstrates very little water absorp-  tion but is well absorbed by other tissue components [17].  This allows it to be transmitted through water-rich environ-  ments while having similar tissue effects as the CO. Minimal  lateral thermal damage, precise depth of cut, and good coag-    ulation combined with its ability to be used in presence of  saline/lactated Ringer’s solution makes it the preferred laser  for operative TMJ arthroscopy [18].   Diode lasers at wavelengths between 805 and 980 nm have  been reported to be compact, inexpensive, and easy to use in  OMS procedures (Fig. 39.4). These can be used in continuous  or pulse modes with contact or noncontact handpieces.  However, it should be understood that these wavelengths are  not well absorbed by soft tissues (although pigmented tissue  will absorb it the most), the use of this laser wavelength  would lead to very limited effects on surface tissue and very  deep, poorly controlled, and undesirable tissue penetration.  This is bypassed by using a material on the tip of the fiber that  absorbs these wavelengths (either pigmented material such as  ink paper or a suitable crystal material) and creates a red hot  thermal tip, which is then used in surgery. In reality, the laser  wavelength produced is not actually used for surgery; it is  only absorbed by the fiber tip to essentially produce a thermal  cautery. Although diodes are cheap and easy to use due to  their fiberoptic contact tip, this thermal cautery effect rather  than the use of the actual laser beam is very inefficient for  surgery and severely limits its use by the OMS [19].    Three basic categories of application of lasers in OMS  can be classified as follows:    1. Incisional/excisional procedures  2. Vaporization (tissue ablation)-based procedures  3. Surgical hemostasis    Incisional procedures require a precise thin cut with careful  control of the depth of the cut. The thickness or thinness of  the cut with a laser is controlled by the spot size (usually  0.1-0.4 mm). The laser beam’s focal length is usually  between | mm and | cm, depending on the delivery system,  and is where the smallest spot size can be achieved with  maximum power density. This is called “focused mode”  (Fig. 39.5). The laser can be controlled by a foot pedal, but it  is often useful to limit time on tissue to speeds faster than a  foot control allows. Hence, a “gated/pulsed mode” can be  used to generate 2—20 pulses per second to create or mark a  dotted outline with lesser depth and allow careful delineation  of the margins of the excision. This is then followed by a  continuous mode (using the foot pedal) to “connect the dots”  and complete the excision. The settings to obtain a desired  depth of cut vary from one tissue to another due their differ-  ent water content and absorption coupled with the surgeon-  controlled factors as mentioned earlier. It is not possible to  have standard laser parameters for all types of tissues or  lesions. The smallest spot size possible with 4-10 W power  can be a good initial setting. The initial cut then gives the  surgeon ability to observe the clinical effect and depth of  incision, which then can be used to lead to adjustments of the  power and time on target to achieve the desired changes.  Common soft-tissue lesions that can be incised or excised  using lasers include fibromas, mucoceles, epulis fissuratum,  mucosal or gingival lesions, papillomas, etc. Wound closure  after a laser-assisted incisional biopsy or excisional proce-  dure is often unnecessary due to the limited scarring and  excellent hemostasis and is up to the surgeon’s discretion, as  healing is excellent regardless of closure. Closure does not  usually effect hemostasis or pain relief (Fig. 39.6a—c) [5].    Fig. 39.6 (a) Lesion of tongue. (b) Tongue after laser excision with no  closure. (c) Excellent healing    Ablative or vaporization procedures are done when the  surgeon wants to remove only a superficial layer of the tis-  sue. Lasers, cryotherapy, chemical peeling, and scalpel can  be used for this purpose, but the precision of cut and control  of the depth of tissue changes along with excellent hemo-    stasis make lasers the preferred tool for vaporization proce-  dures. Lasers, when used for vaporization procedures, are  used defocused so as to decrease the power density (the  energy per unit area) and limit the depth of effect while  increasing the area of the tissue ablation. The spot size used  for vaporization ranges from 1.5 to 3 mm and allows large  surface areas to be removed very superficially (literally cell  layers at a time if desired). This is ideal for large but flat  and superficial lesions such as hyperkeratosis, dysplasia,  lichen planus, etc. The laser is again used in gated mode to  carefully and precisely outline the margins. This is fol-  lowed by passing the laser in overlapping “U”-shaped pat-  terns to cover the entire area. The parameters can be  adjusted by the surgeon, just as in incision cases, after the  first pass is done at 4-10 W power. As implied by vaporiza-  tion, there is no tissue available for biopsy in these cases.  Hence, a definitive diagnosis should be established prior to  performing ablative or vaporization procedures on mucosal  lesions (Fig. 39.7a—c).   Due to the ability of CO, lasers to constrict blood ves-  sels rather than coagulate blood, it can be an excellent tool  to obtain hemostasis in most surgical wounds where the  vessels are smaller than the thermal effect of the laser in  tissue (about 500 1). The lateral thermal effect of the laser  beam should be equal to or greater than the diameter of the  bleeding vessels. If the vessel is of larger diameter, conven-  tional hemostatic techniques should be used. For small  superficial vascular lesions, the CO, laser can be used to  excise the lesion (since the feeding vessels are usually  smaller than 500 1), while deeper or larger vascular lesions  are best treated using lasers that are specifically absorbed  by hemoglobin, leading to true coagulation of the lesion  itself [6].    39.5 Specific Examples of Application  of Lasers in Oral and Maxillofacial  Surgery   The use of lasers in cosmetic surgery has changed  these procedures significantly over the years. The advan-  tages of lasers as previously described, including the  capability of lasers to only affect the superficial layers of  skin with precise depth control, turned out to be its criti-  cal advantage. Lasers in cosmetic facial surgery can be  used both for incisional or ablation procedures based on  indication [20].   Lasers used for laser skin resurfacing (removal of  superficial skin wrinkles from the face) are an example of  ablation or vaporization procedure. In skin resurfacing  procedures, the superficial layers of the epidermis and    Fig. 39.7 (a) Hyperkeratosis of lateral tongue. (b) Laser ablation of  tongue. (c) Healing after laser ablation    papillary dermis are removed while leaving behind the  reticular layer of the dermis with its adnexal structures.  This layer, if intact, provides epithelial cells that are  required for rapid re-epithelialization of skin in a uniform    manner. As opposed to chemical peels or dermabrasion,  lasers offer more precise depth control, which is crucial in  uniform healing and improved outcomes. CO, and the  Er: YAG are the commonly used lasers for skin resurfac-  ing, although recent improvements in the way CO) is used  to improve results with lessened postoperative healing  time, have severely diminished the use of the  Er: YAG. Although the CO, laser is most commonly used  and is more effective, it can be associated with long-term  erythema and greater risk of scarring if exposure is done  too deeply. Since CO, is a continuous-wave beam, which  means that even at a short “pulse” the laser would be on  tissue too long and lead to scarring, it must be electroni-  cally “pseudopulsed” at high powers to obtain the short  times needed to reduce risk from lateral thermal damage  to the unintended underlying dermis (roughly less than  1000 pls). On the contrary, the Er: YAG laser has less pen-  etration in skin owing to its higher affinity to water in  tissue. It is also a true pulsed laser and hence it allows  higher power with shorter pulse duration. Although this is  an advantage of Er: YAG laser, which helps reduce risk of  excessive ablation and scarring, as mentioned before, it  also decreases the effectiveness and results of the Er: YAG  laser and most surgeons have abandoned its use in favor  of newer CO, lasers that create very deep but thin vertical  columns in the skin, allowing for tissue contraction with  quick healing and less chance of scarring [21].    In skin resurfacing, as opposed to ablation of intraoral  mucosal pathology, the passes of laser should not be over-  lapping to avoid excessive tissue ablation (Fig. 39.8).  Computer pattern generator handpieces (CPG) can be  used, which automatically create a uniform pattern of  coverage on the skin (Fig. 39.9a, b) [22].   Skin resurfacing principles are also used in scar revi-  sion procedures. The prominence or visibility of a scar is  mainly affected by the surface depression or elevation.  The CO, and Er:YAG lasers can be used to reduce the  elevation of the scar tissue or decrease the elevation of the  surrounding skin to make a depressed scar tissue blend  well with it (Fig. 39.10a—c). Healing scars can also have  hypervascularity as evidence by prolonged erythema.  This can be managed by decreasing the vascularity within  the scar by use of vascular-specific lasers such as 532-nm  KTP: YAG or Pulsed Dye Lasers (PDL) lasers [23].   In blepharoplasty, the CO, laser can be used to make a  transconjunctival incision on the lower eyelid as well as the  skin incision for the upper eyelid blepharoplasty. The use of  laser to then excise muscle or fat with excellent hemostasis  provides great visualization and tissue control (Fig. 39.11).   In endoscopic brow lift techniques, lasers are passed  through either flexible fiberoptic cables or through small  diameter hollow waveguide extensions in order to be used  for incisions made within the optic cavity. The advantage  of using lasers in endoscopic procedures is to provide pre-  cise incisions with excellent hemostasis, which aids in  better visualization. Laser is used to incise the periosteum  and/or muscle attachments. CO, laser is a commonly used  laser for this purpose.    Lasers have been extensively used in intraoral mucosal  surgeries. Common applications include incisional/exci-  sional biopsy of intraoral soft-tissue lesions (Fig. 39.12a—  c), frenectomy (Fig. 39.13a, b), ablation of premalignant  lesions, preprosthetic procedures such as vestibuloplasty  and excision of epulis fissuratum (Fig. 39.14a—d). As men-  tioned previously in this chapter, advantages of lasers stand  superior compared to traditional scalpels in terms of wound  healing, tissue handling, and hemostasis, which ultimately  help improve patient experience when used for intraoral  procedures as well. Vaporization or ablation of tissues  intraorally is usually performed on premalignant lesions,  commonly for white lesions such as hyperkeratosis or mild  epithelial dysplasia. More severe dysplasias are best  excised with the laser to allow for margin control. Definitive  diagnosis with the help of a biopsy is a precursor for man-  agement of premalignant lesions with laser vaporization  since there will be no specimen to biopsy [24].   Although diode, ND:YAG, Er:YAG and CO, lasers  can be used for intraoral mucosal surgeries CO, lasers  stand out as the workhorse and most studied laser over the    past four decades. When using lasers intraorally on  intended soft tissues, care must be exercised to protect  adjacent hard/soft tissue from inadvertent damage or  devitalization due to pulpal damage. This is done with  either a moist gauze, a mouth guard, a wet tongue blade,  or nonreflective plastic instrumentation [25]. The use of  lasers as compared to scalpel is presumed to also provide  a decreased chance for lymphatic and hematogenous  seeding as an added advantage in the management of pre-  malignant or malignant lesions. Principles and technique  of incision and ablation have been detailed elsewhere in  the chapter.    Lasers are also useful in the management of peri-  implant soft tissues. 10,600-nm wavelength CO, laser and  980-nm diode are the commonly used soft-tissue lasers in  implant surgery. ND:YAG laser, due to its inherent high  depth of penetration and risk for damage to adjacent tis-  sue and implant surface, is considered unsafe for use on  implants. Er: YAG laser, which has been approved for use    Fig. 39.9 (a) Computerized pattern generator (CPG) for laser skin resurfacing. (b) Optional patterns for CPG    on hard tissues, has been used in uncovering a thin layer  of bone in second-stage implant uncovering and initiating  the implant osteotomy, but there is need for further data  on the use of Er: YAG for complete preparation of implant  osteotomy. 9300-nm CO, laser has been used for hard-  tissue applications, but more data on its safety and effi-  cacy are needed. Advantages of using lasers in implant  surgery include the precision, atraumatic tissue handling,  bloodless field of view, and decreased bacterial contami-  nation. Lasers have been used for several indications in  implant surgery, including implant site preparation proce-  dures such as the release of frenal attachment, excision of  redundant tissue, and incision placement prior to bony  osteotomy. Placement of incisions with lasers as opposed  to scalpel creates less inflammation, swelling, and post-  operative discomfort to the patient as well as added prop-  erty of tissue sterilization from antibacterial effect. They  can also be used for second-stage surgery, including  removal of soft tissue and, in the case of Erbium lasers  and 9300 nm CO, lasers, bone covering the implant [26].    tis is deemed stable without severe bone loss and/or  mobility, then treatment is attempted to salvage. Treatment  of choice includes debridement of the granulation tissue  accompanied by the administration of antibiotics around  the implant for the eradication of as much bacteria as pos-  sible followed by bone graft of any defect created.  Traditional tools include plastic instruments, citric acid,  chlorhexidine, and topical Tetracycline. A laser-assisted  algorithm for management of peri-implantitis includes  obtaining access to the implant in question via a laser  incision and reflection of flap leading to exposure of  implant and surrounding bone. Then, the pathologic tis-  sue is vaporized by laser energy and the implant surface  and bony defect are decontaminated by the laser, which is  ©Association of Oral and Maxillofacial Surgeons of India accomplished by ablating the surface at low energies to  kill off any bacteria on the surface as well as any attached  soft tissue. Bone grafting, if necessary, can then be per-  formed. Data have shown significantly better outcomes in  cases of peri-implantitis as compared to conventional    Fig. 39.10 (a) Depressed scar of face. (b) Blending of scar using CO,  laser. (c) Results of laser scar revision    Treatment of mucositis and peri-implantitis around tools. As in other laser-assisted surgeries, healing is  implants is a challenging problem in implant surgery with enhanced because of reduced inflammation and decreased  limited efficacy when managed via conventional treat- postoperative pain as opposed to conventional tools [26]    Fig. 39.12 (a) Outlining a small tongue cancer for laser excision. (b) Excision of lesion with CO, laser. (c) Lesion excised and allowed to heal  with no closure    Fig. 39.13 (a) Laser frenectomy with CO, laser. (b) After laser frenectomy    Fig. 39.14 (a) Epulis fissuratum of maxilla. (b) Excision of epulis with CO, laser. (c, d) Supraperiosteal dissection allowed to secondary heal   Arthroscopic TMJ surgeries have been proven to be  efficacious, minimally invasive, and efficient procedures  to treat and manage several aspects of temporomandibu-  lar joint disorders. Arthroscopic surgery utilizes various  modified cutting instruments, which are passed through  a narrow trocar to be able to release the disc attach-  ments, remove redundant inflamed tissues, and/or per-  form synovial biopsies. These conventional cutting tools  are difficult to maneuver, increase the risk of bleeding,  which creates a poor visual field and a higher risk of  complications. Use of lasers administered via narrow-  diameter fiberoptic cables adds advantages in maneu-  verability, which makes it easier to sweep through the  small-sized TMJ and make precise incisions and abla-  tion with better hemostasis in a noncontact mode. Due  to their high water absorption, CO, and Er: YAG lasers    cannot be used for this purpose. Ho:YAG is the com-  monly used laser for the purpose of TMJ arthroscopy.  With low water absorption, it is less affected by the pres-  ence of the synovial and lavage fluids, while low pene-  tration (~0.5 mm) decreases the risk of damage to  adjacent tissues. Other TMJ procedures such as disk  repositioning and removal have been described with the  use of arthroscopic techniques and laser assistance with  significant success (Fig. 39.16) [17, 18].    Efficient and safe use of lasers starts with operator’s famil-  iarity with details of the laser system in use. All laser systems  come with a user’s manual, which lists all required technical  details as well as recommended indications for use of that  laser system. Common safety issues with lasers happen with  accidental exposure of surrounding tissues.   Patients, providers, and the assistants are all at risk of  inadvertent irradiation with lasers. Any reflective surface  in the area of laser target can divert the beam away from  the intended area and potentially cause harm. Use of spe-  cial protective glasses (that are matched to the specific  wavelength of the laser) can help avoid injury to eyes of  patients or personnel in the operatory. Everyone in the  operatory should be familiar with the basic functioning of  the laser equipment and nonreflective tools should be  used and reflective surfaces intraorally such as crowns be  protected with a wet sponge or nonreflective retractors.  Posting a “danger” sign for use of laser on the door of the  operatory in order to avoid unprotected personnel from  entering the room, while laser is in use could avoid acci-  dental injuries as well (Fig. 39.17a, b) [6].    Fig. 39.17 (a) Wavelength-specific eyewear for protection of operator, patient, and assistants. (b) “Danger” sign outside the operatory along with  closure of any see-through glass panels on the door    2. Fire hazard: 39.7 Conclusion  Lasers in an oxygen-rich environmental such as the  oral cavity of a patient being provided supplemental oxy- Lasers have changed the OMS practice significantly to a  gen, or inside an endotracheal tube, can pose a significant point that it is today an essential surgical tool in many ways.  fire risk. To avoid fire, supplemental O, concentration Development of lasers in future may overcome current dis-  should be kept to a minimum required level or use of advantages and increase utility and safety. Use of lasers in  room air is recommended. For endotracheal tubes, com- hard tissue is still somewhat limited in comparison to soft-  pressed air can be substituted for oxygen to keep the _ tissue applications. Further research and development could  inspired concentrations of oxygen to below 30% [6]. help improve this aspect of laser.DisclosureAuthors have no  3. Laser plume: financial conflicts to disclose.  When a laser is used for incision or vaporization pro-  cedures, the tissue that is being handled will create a  “plume,” which consists of potentially hazardous particu- References  late debris, which is considered infectious. There are  studies, which showed the presence of viral DNA in the 1. Hecht J. Beam the race to make the laser. Oxford: Oxford University    ; es fi Press; 2005.  plume, but to date there hasn't been any clinical signifi- 2. Maiman T. Comments on his precocious five-year-old [editorial].    protective barriers such as eyeglasses will help avoid Convissar R, editor. Principles and practice of laser dentistry. 2nd  infection transmission as well [27-29]. ed: Elsevier Health Sciences; 2016. p. 12-26.    surgery. In: Convissar R, editor. Principles and practice of laser  dentistry. 2nd ed: Elsevier Health Sciences; 2016. p. 234-50.    . Barak S, Kaplan I, Rosenblum I. The use of the CO2 laser in oral    . Bradley P. A review of the use of the neodymium YAG laser    in oral and maxillofacial surgery. Br J Oral Maxillofac Surg.  1997;35(1):26-35.    . Romanos G. Clinical applications of the Nd:YAG laser in oral    soft tissue surgery and periodontology. J Clin Laser Med Surg.  1994; 12:103-8.   White J, Goodis H, Rose C. Use of the pulsed Nd:YAG laser for  intraoral soft tissue surgery. Lasers Surg Med. 1991;11:455-61.  Khatri KA, Ross V, Grevelink JM, Magro CM, Anderson  RR. Comparison of erbium:YAG and carbon dioxide lasers in  resurfacing of facial rhytides. Arch Dermatol. 1999;135:391-7.   Li Z, Reinisch L, Van de Merwe W. Bone ablation with Er: YAG and  CO2 laser: study of thermal and acoustic effects. Lasers Surg Med.  1992;12:79-85.   Armabat-Dominguez J, Espana-Tost AJ, Berini-Aytes L, Gay-  Escoda C. Erbium:YAGlaser application in the second phase of  implant surgery: a pilot study in 20 patients. Int J Oral Maxillofac  Implants. 2003;18:104—12.   El-Montaser M, Devlin H, Dickinson MR, Sloam P, Lloyd  RE. Osseointegration of titanium metal implants in erbium-YAG  laser-prepared bone. Implant Dent. 1999;8:79-85.   Walsh L. The use of lasers in implantology: an overview. J Oral  Implantol. 1992;18:335—40.   Kreisler M, Kohnen W, Marinello C, Gote H, Duschner H, Jansen  B, dHoedt B. Bactericidal effect of the Er:YAG laser on dental  implant surfaces: an in vitro study. J Periodontol. 2002;73:1292-7.  Hendler BH, Gateno J, Mooar P, Sherk HH. Holmium: YAG laser  arthroscopy of the temporomandibular joint. J Oral Maxillofac  Surg. 1992;50:93 1-4.    Koslin M. Laser applications in temporomandibular joint  arthroscopic surgery. Oral Maxillofac Surg Clin N Am.  2004; 16(2):269-75.   Romanos G, Nentwig G. Diode laser (980 nm) in oral and maxil-  lofacial surgical procedures: clinical observations based on clinical  applications. J Clin Laser Med Surg. 1999;17:193-7.   Mitchell O, Blackhall K, Lister T, Downie I. The use and applica-  tion of lasers in oral and maxillofacial surgery. Br J Oral Maxillofac  Surg. 2017;55(10):E155.    . Guttenberg SA, Emery RW III. Laser physics and tissue interaction.   Watson SW, Sawisch TJ. Cosmetic ablative skin resurfacing. Oral  Maxillofac Surg Clin N Am. 2004;16(2):215-30.   Boyden DK. A brief overview of noninvasive lasers in cos-  metic maxillofacial surgery. Oral Maxillofac Surg Clin N Am.  2004; 16(2):23 1-7.   Wlodawsky RN, Strauss RA. Intraoral laser surgery. Oral  Maxillofac Surg Clin N Am. 2004;16(2):149-63.   Stephen Brandon M, Strauss RA. Complications of CO2 laser pro-  cedures in oral and maxillofacial surgery. Oral Maxillofac Surg  Clin N Am. 2004; 16(2):289-99.   Julian J. Lasers in implant dentistry. In: Convissar R, editor.  Principles and practice of laser dentistry. 2nd ed: Elsevier Health  Sciences; 2016. p. 107-30.   Bellina JH, Stjernholm RL, Kurpel JE. Analysis of plume emis-  sions after papovavirus irradiation with the carbon dioxide laser. J  Reprod Med. 1982;27:268-70.   Mullarky MB, Norris CW, Goldberg ID. The efficacy of the CO2  laser in the sterilization of skin seeded with bacteria: survival  at the skin surface and in the plume emission. Laryngoscope.  1985;95:186-7.   Walker NPJ, Matthews J, Newson SWB. Possible hazards from  irradiation with the carbon dioxide laser. Lasers Surg Med.  1986;6:84-6.    Open Access This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.  org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropri-  ate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.   The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in  a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.   The term “piezo” has been derived from the word “Piezien,”  which implies pressure in the Greek language. Piezoelectric  effect was first described by Jacques and Pierre Curie in  1880 and involves the appearance of an electric charge across  certain crystals when they are under mechanical pressure.  Inversely, when an electric current is applied across them,  they deform. This phenomenon of deformation when under  alternating current creates microvibrations or oscillations of  ultrasonic frequency [1]. Although ultrasonic microvibration  technology was experimentally used earlier, it was in 1988  that Italian oral surgeon Tomaso Vercellotti developed the  first commercially available Mectron® piezoelectric bone  surgery unit to cut bone tissue while minimizing the limita-  tions of conventional tools [2, 3]. The first use of piezoelec-  tric surgery was for osteotomies by oral and maxillofacial  surgeons and later on used for neurosurgical and orthopedic  procedures. This revolutionary tool not only lowers the  chance of damage to adjacent vital soft-tissue structures such  as nerves and vessels during osteotomies, but also preserves  osteocytes, which in turn complements bone healing [4, 5].    Piezoelectric surgery devices are generally small portable  units comprising a handpiece with a working tip and a foot  control switch, which are connected to the main power-  generating unit. The main power unit also features holders  for the handpiece and irrigating/cooling fluid (Fig. 40.1a—c).  The handpiece is the critical part of this device, containing  within it the ceramic chips where the microvibrations are  created and later transmitted to the working tip. Commonly   Department of Oral and Maxillofacial Surgery, Virginia  Commonwealth University Medical Center, Richmond, VA, USA  e-mail: srenapurkar@vcu.edu; nagamallas @vcu.edu    © The Association of Oral and Maxillofacial Surgeons of India 2021    used ceramic chips in Piezoelectric surgery units are Barium  Titanate or an equivalent material. The amount of deforma-  tion in the crystals within the handpiece and resultant vibra-  tions in the insert depend on the power applied [6].   The working tips of a piezoelectric system used for surgi-  cal purposes are interchangeable inserts, which can be of dif-  ferent shapes, sizes, and cutting edges based on the intended  clinical applications. These inserts can be made of different  materials and be coated with titanium or a diamond layer to  improve the cutting efficiency. To create a cutting effect  rather than a debriding effect, the vibrations of the insert  enter into a resonance with the ceramic chips, which increases  the energy output. This, combined with the form of the insert,  acts like a micrometric oscillating saw. The main energy unit  has an interactive touchpad, which allows the operator to  control the frequency of vibrations, power of the unit, and  the amount of irrigating or coolant fluid. The pressure applied  on the insert can also be manually controlled by the operator  and can affect the frequency delivered to the target tissue,  which in turn affects the cutting efficiency. When higher  pressure is applied at the tip, it impedes the cutting efficiency  of the insert and releases the energy as heat, which is detri-  mental to the bone as well as adjacent soft tissue [6, 7].   The Piezoelectric unit also allows for election of modes of  operation, which are preset power modes with varying fre-  quencies to match the clinical application. The frequency is  usually set between 25 and 29 kHz, which can create micro-  oscillations of 60-210 fm amplitude, providing the hand-  piece with power exceeding 5 W. The vibrations produced in  the “Low mode” result from average ultrasonic powers,  without frequency overmodulation, and allow the operator to  perform endodontic procedures. On the contrary side, the  “high mode” and the “boosted mode” are characterized by  vibrations with higher ultrasonic power and frequency over-  modulation, which allows cutting of mineralized tissue. The  “boosted mode” has frequency overmodulation with an  increased rate that is most efficient for osteotomy and osteo-  plasties in surgical procedures, while the “high mode” is less    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1-15-1346-6_40    Fig. 40.1 (a) The Piezosurgery® unit from Mectron® is made of a power supply unit, a handpiece, its holder, an irrigant solution holder, foot  control switch. (b, ¢) Inserts or working tips of a piezosurgery unit. (b) shows working tips for Sinus lift and (c) shows osteotomy tips    efficient but more helpful in periodontal procedures and  bone smoothening [6-8].   The device includes an irrigating system for cooling that  creates an adjustable jet of coolant solution through a peri-  staltic pump at rates between 0 and 60 ml/min and helps  remove debris from the cut surface and helps maintain hemo-  stasis because of its cavitation effect. This enhances visibil-  ity, particularly in difficult-to-reach anatomical zones, by  scattering coolant liquid as an aerosol. The irrigation liquid  should be refrigerated at 4 °C for effectual cooling [6, 8, 9].   For optimal use and maximum efficiency, the operator  could select the proper power based on the surgical tissue,  apply light pressure with the tip, and adjust the rate of deliv-    ery of the irrigating solution to avoid overheating the tissue  and decrease the chance of damage to soft tissues. Although  the device has a safe frequency range along with the cooling  irrigation liquid, there is a possibility of damage to soft tis-  sues due to high pressure and overheating [10].    Used in many therapeutic surgical procedures, piezosurgery  has several advantages when compared to traditional meth-  ods of surgical instrumentation used for osteotomies or  osteoplasty. These are as follows:    ¢ Decreased risk of damage to adjacent soft tissues: This is  the major advantage with use of a piezoelectric surgical  unit. When used as recommended, at the appropriate fre-  quency, the micrometric oscillating motion decreases the  chance of damage or cutting of adjacent soft tissue while  cutting through hard tissues. For example, it allows  improved Schneiderian membrane preservation during  osteotomy of the maxillary lateral wall during a sinus lift  and preservation of the inferior alveolar nerve (IAN) dur-  ing mandibular osteotomy.   ¢ Improved visibility: With use of piezosurgery, better visi-  bility is secondary to the decreased amount of bleeding  and the phenomenon of cavitation. Cavitation refers to the  phenomenon of “microboiling” occurring in liquids in a  solid-liquid interface at intermediate frequencies of vibra-  tion secondary to the creation of imploding bubbles when  the irrigating solution contacts the insert. Improved visi-  bility helps the operator to place the osteotomy in the pre-  ferred location with increased accuracy [6].   ¢ Increased patient comfort: Due to the micrometric nature  of the vibrations and decreased noise, use of a piezosur-  gery device improves patient comfort and decreases anxi-  ety during procedures done under local anesthesia. When  used for bone harvesting, it also reduces the need for use  of chisels, which can help improve the patient experience  and reduce stress.   ¢ Improved survival of osteocytes: Bone harvested with var-  ious techniques, including rotary instruments, chisels, ron-  geurs, and a piezosurgery device, was studied with  histomorphometry evaluation by Berengo et al. The piezo-  surgery device was shown to be one of the best methods of  harvesting bone along with gouge chisels, back action  chisels, and rongeurs in terms of the viability of the har-  vested bone and number of osteocytes. Bone harvested  with rotary instruments, including burs and safe scrapers,  was noted to be completely nonvital with an absence of  osteocytes. In another histomorphological study done with  the placement of porous titanium implants in minipig tib-  ias, neo-osteogenesis was noted to be consistently more  active in bony samples from implant sites that were pre-  pared using piezoelectric surgery, and there was an earlier  increase in BMP-4 and TGF-2 proteins and fewer proin-  flammatory cytokines in bone around the implants [5, 11].    Although piezosurgery has numerous advantages as listed  here, it is associated with some drawbacks as follows:    ¢ Low efficiency/increased operating time: One of the major  drawbacks with ultrasonic/piezo surgery osteotomes is  the increased time required for the procedure. The cutting    efficiency of a piezosurgery device has been reported to  be 3-4 times less than that of conventional osteotomes for  some procedures [12, 13]. For example, in a randomized  prospective crossover clinical study done by Stefano  Sivolella, piezoelectric osteotomy of a lower third molar  took 9.4 min longer than rotary tools to complete [14].   ¢ Expense: The cost of equipment is sometimes an addi-  tional burden to the provider. Each individual cutting tip  in a piezosurgery equipment setup is generally more  expensive than traditional cutting tools such as burs, chis-  els, or saw blades. These tips can also potentially break or  fracture when improperly used, which can again increase  the need for more equipment.   e Learning curve: Use of piezo requires a short learning  curve to attain maximum efficacy, which could be frustrat-  ing to the operator. The digital pressure applied by the sur-  geon while using conventional tools such as saws and  drills is quite different from piezoelectric surgery as it  mandates less pressure and failing to calculate the pressure  according to the speed of the insert prevents microvibra-  tions of the insert. When the microvibrations are prevented  due to excessive pressure on the working tip, energy not  used for cutting will be transformed into heat, which, if it  continues for long time, would damage the tissue.   ¢ Pacemakers and defibrillators: Piezosurgery is relatively  contraindicated for use in patients with pacemakers,  although there is no evidence of electromagnetic interac-  tions produced by piezoelectric devices according to one  in vitro study [15].    Piezosurgery can be applied toward multiple dentoalveolar pro-  cedures where there is a requirement for meticulous bone prepa-  ration, atraumatic tooth extraction/exposure, and when the  location of the surgical site is in proximity to vital anatomical  structures. Example of applications in dentoalveolar surgery  include ankylotic tooth root extraction, impacted third molar  extraction, surgical exposure of impacted teeth, and extractions  in patients with a thin periodontal biotype. In all of these indica-  tions, piezosurgery has the potential to limit bone loss and maxi-  mize maintenance of alveolar bone integrity, especially when  the alveolar bone is thin and the procedure requires a high  degree of precision. A split-mouth design, randomized, clinical  trial conducted by Mantovani et al. studied differences in post-  operative pain, orofacial swelling and duration of the procedure  when using a rotary bur for third molar ostectomy versus a  piezosurgery device. They found that, although the duration of  the procedure was longer, the postoperative pain and swelling  were less in the piezosurgery group [16].   Perforation of the Schneiderian membrane during lateral  wall osteotomy, and/or while raising the maxillary sinus  floor manually, is a common complication, which can affect  the bone grafting procedure. Use of piezosurgery in sinus lift  procedures not only minimizes the chance of perforation  during osteotomy but also eases the separation of the mem-  brane as well (Fig. 40.2a—c). In the commonly used lateral  approach technique for sinus lift, piezoelectric devices have  a superior action in each technique or step compared to    Fig. 40.2 (a) Piezosurgery insert used to perform outline of the lateral  wall osteotomy to thin the wall. (b) Blunt piezosurgery insert used to  infracture the window wall and initiate the separation of the schneide-  rian membrane from the sinus wall. (c) After the lateral sinus wall oste-    traditional instruments. The chance of membrane perforation  with conventional techniques is reported to be 14-56%,  while studies on the use of piezosurgery devices report it to  be 5-7% [8, 17, 18].    ¢ Thinning buccal wall: With traditional instruments, it is  difficult to thin the buccal wall with good control.  Piezoelectric device makes precise osteoplasty easy and  the bone fragments produced during osteoplasty can be  used as grafting material.   ¢ Bony window/osteotomy: Piezosurgery makes the frame  of the bony window optimal with respect to the sinus    otomy completed, membrane separation initiated a third insert shaped  as an elevator used to continue the separation of the membrane to create  required space for the bone graft for augmentation   e Sinus membrane separation: Most commercially avail-  able piezosurgery devices have special inserts that make  the separation around the perimeter of bony window eas-  ier and decrease chance of tear or perforation during the   Implant site healing and ultimate osseointegration of  implants is negatively influenced by the high temperatures  created during site preparation. Results of an in vitro study  done by Heinemann et al. in 2012 on porcine jaws compar-  ing piezosurgery, Sonicflex®, and rotary instruments showed  the highest temperature rise with use of piezosurgery,  although the trabecular bone and osteocytes were still intact  [19]. On the contrary, a recent randomized, controlled clini-  cal trial by Da Silva Neto et al. in 2014 compared implant  stability at various times postoperatively in osteotomies per-  formed by conventional rotary instruments versus piezosur-  gery devices, and found implant stability to be higher with  Piezosurgery [20]. The use of piezoelectric devices facili-  tates the use of selective enlargement of only one socket wall  and Vercellotti called this: “differential ultrasonic socket  preparation.” [4].   Ridge-splitting techniques for alveolar augmentation is indi-  cated when there is adequate height of bone for implant  placement but inadequate ridge thickness. The conventional  ridge-splitting procedure uses chisels, rotary instruments, or  saws, all of which have a high risk for damage to soft tissue,  undesired propagation of the osteotomy and bone fracture, as  well as prolonging treatment time due to the need for second-  stage surgery to place the implants. (Fig. 40.3a, b) With use    of piezosurgery, one can decrease the chance of the damage  to adjacent structures during the osteotomy as well as reduce  the risk of bone thermonecrosis, while simultaneously pro-  viding better control of propagation of the ridge split osteot-  omy. Although ridge splitting was traditionally used in the  maxillary arch, piezoelectric bone surgery allows ridge  expansion even in highly mineralized tissues like the man-  dible with ease [21, 22]. Blus et al. conducted a study on  ridge splitting for more than 200 implants placed in 57  patients and reported 96.5% success rate with a 36-month  follow up [23].   In order to place implants in atrophic edentulous mandibles,  IAN lateralization can be used as an alternative to bone aug-  mentation procedures (Fig. 40.4a—-c). Bovi, in 2005, first  reported a technique for IAN mobilization with simultane-  ous implant placement utilizing a piezoelectric device. He  reported that IAN mobilization with a piezoelectric device  minimizes the risk of irreversible damage to the IAN and  enables the surgeon to make a smaller bony window, which,  in turn, decreases overstretching of the mental nerve [24]. In  an in vitro study, Metzger compared transposition of the IAN  with use of a piezoelectric device versus conventional burs.  His study also supported the lower rate of nerve injury from  use of piezosurgery [25].    For bone augmentation, bone grafts in the form of chips or  blocks can be used. Bone chips are primarily indicated in  guided bone regeneration where the stabilization of the graft  is not an issue, such as multiwalled defects. On the other  hand, when the bony defect is large or stabilization is diffi-    Fig. 40.3 (a, b) Ridge split technique with piezo surgery. Bony oste-  otomies performed with piezoelectric device then ridge expanded to  desired dimensions. From: Tarun Kumar, A., Triveni, B., Priyadharshini,    M., & Mehta, G. (2016). Staged Ridge Split Procedure in the  Management of Horizontal Ridge Deficiency Utilizing Piezosurgery.  Journal of Maxillofacial and Oral Surgery, 15(4), 542-546 (Springer)    Fig. 40.4 (a-c) Inferior alveolar nerve (IAN) lateralization for placement of implant    cult, block grafts must be utilized to augment vertical or  horizontal dimension. Piezosurgery is used for harvesting all  types of bone grafts, including autologous free block grafts,  microvascular free flaps, and bone chips.   For example, piezosurgery is commonly used to harvest  mandibular ramus block grafts. This requires use of two  types of piezosurgery inserts. One is the standard saw-shaped  right angle insert, which is used in an area, which can be  viewed directly to make the depth cut and vertical cuts, while  a second, dual-angled, insert is used specifically to make the  inferior horizontal bone cut. In bone graft harvesting, piezo-  surgery allows better visibility, precise cuts, and good adap-  tation of the grafts along with better survival of bone cells. In  a study by Happe in 2007 on 40 patients, bone grafts har-  vested from the mandibular ramus by piezosurgery resulted  in 93% uneventfully healed donor sites and 96% unevent-  fully healed graft sites [26]. There was also minimal resorp-  tion of the graft. Shaping of block grafts can be better  controlled with piezosurgery, although this can take longer  than rotary instruments. In microvascular free bone flaps har-  vested with piezosurgery, the surgeon can decrease the  chance of injury to the vascular bundle along the surface of  bone. With the use of piezoelectric surgery, the clinician can  cautiously osteotomize the fibula or other bone without any  periosteal/pedicle dissection. In addition, the piezoelectric  method also allows shaping and handling the pedicle while it  is still attached to the donor site.    Piezoelectric devices are increasingly being used in orthogna-  thic surgery due to its precise cutting and lower risk of damage  to adjacent teeth and nerves. Landes et al. performed a large  study on 90 patients in whom orthognathic surgery was per-  formed with piezosurgery. This study demonstrated decreased    blood loss compared to conventional surgery but no significant  difference in surgical times. Lefort I osteotomy only required  the use of chisels in about 33% of cases [5, 27, 28]. In the same  study, among patients who underwent bilateral sagittal split  osteotomy (BSSO), inferior alveolar nerve sensitivity at  3-month follow up was retained in 98% of the cases, com-  pared with 84% after conventional BSSO (Fig. 40.5). When  performing surgically assisted rapid maxillary expansion  (SARME), the advantage of using piezoelectric surgery is that  it minimizes potential damage to the descending palatine  artery while separating the pterygomaxillary junction, the  nasopalatine artery while making the midline maxillary cut,  and it lowers indirect thermal damage to the bony surfaces and  adjacent structures, including teeth [29].    Conventionally, chisels are used for osteotomy of the lateral  nasal bone during rhinoplasty, which transmit significant  force to the surrounding soft tissues in a blind manner, and  increases the risk for bleeding from injury to the adjacent  vasculature. A study done by Robiony et al. assessed use of  chisels versus piezosurgery and found a decreased risk of  injury to adjacent soft tissues with use of piezosurgery. Use  of chisels also may create inaccuracy due to blind use and the  unguarded nature of the instrument. On the other hand, use  of piezo will not incur this issue and gives the operator more  control and accuracy [30].    40.5.6 Distraction Osteogenesis  Distraction osteogenesis (DO) is indicated when there is a    need for significant amounts of bone augmentation or length-  ening, or when the soft tissues that cover the bone will not    Fig. 40.5 (a, b) Orthognathic surgery using Piezo. Figure shows steps in a BSSO. Variations in the blade design can be used based on desired    allow for osseous augmentation. The use of piezosurgery per-  mits the initial osteotomy to be made delicately and accurately  while minimizing injury to the soft-tissue flap and surround-  ing hard tissue, allowing maintenance of the vascularity  needed for successful new bone formation [31]. Distraction  Osteogenesis (DO) can be used for distraction of either the  alveolar bone or the basal jawbone. DO with a piezoelectric  device ensures the preservation of original bone structures,  specifically the cancellous bone, which favors the healing pro-  cess due to its high healing potential. In a recent article, DO  with microdistractors using a piezoelectric device has shown  favorable results in patients with Pierre Robin Sequence [32].    Osteotomies and osteoplasty in the temporomandibular joint  (TMJ) region involves risk to the facial nerve as well as  major vessels such as the internal maxillary artery and the  masseteric artery. Due to anatomical complexity, the use of  conventional bone-cutting tools such as burs and saws may  put these vital structures at risk of injury or permanent dam-  age. Given the advantages of piezosurgery as discussed pre-  viously in the chapter, its use in this specialized surgery is  reasonable and advisable. In 2014, Anson Jose observed less    bleeding along with minimal postoperative complications  while treating TMJ ankylosis with piezosurgery [33].    The IAN is at risk whenever there is the need to extract  impacted mandibular molars, enucleate large cysts, or  remove benign mandibular tumors. In 2009, Dr. Kagan  Degerliyurt presented an article describing a procedure  called the “bone lid technique,” which is performed by using  a piezosurgery device when there is a definitive risk of dam-  age to IAN [34, 35].    Piezoelectric devices can be used for reconstruction in mul-  tiple trauma cases, such as comminuted frontal bar fractures,  to cut and shape the inner table of a calvarial bone graft, to  osteotomize a healing fracture while reducing the chance of  adjacent tissue injury. Using piezosurgery in post-traumatic  cases can help preserve bone, protect adjacent soft tissues,  decrease blood loss, improve visibility, and ensure a better  overall outcome [36].    Piezosurgery is a promising surgical tool for safe and effec-  tive use in various surgeries. For an oral and maxillofacial  surgeon, piezosurgery allows safer and effective osteotomy  or osteoplasty compared to conventional rotating instru-  ments such as burs and saw blades, even in complex ana-  tomical areas. Over the past decade, it has not only been  increasingly used in OMFS but has been adapted for use in  neurosurgery, orthopedic surgery, and otorhinolaryngology.  In addition to the surgical advantages, it helps the patient by  reducing procedural stress, postoperative swelling, pain and  overall improves the surgical experience. The major draw-  back of piezosurgery is the lack of efficiency or cutting  speed, which can be balanced by improved clinical out-  comes. Future generations of ultrasonic devices may bring  about better efficiency and ultimately replace all conven-  tional cutting tools.    1. Curie J, Curie P. Contractions et dilatations produites par des ten-  sions dans les cristaux hémiédres a faces inclinées. C R Acad Sci  Gen. 1880;93:1137-40.   2. Vercellotti T. Technological characteristics and clinical indications  of piezoelectric bone surgery. Minerva Stomatol. 2004;53:207-14.   3. Aly L. Piezoelectric surgery: applications in oral & maxillofacial  surgery. Future Dent J. 2018;4(2):105-11.   4. Vercellotti T. Essentials in piezosurgery: clinical advantages in den-  tistry. Milan: Quintessence; 2009.   5. Berengo M, Bacci C, Sartori M, et al. Histomorphometric evalu-  ation of bone grafts harvested by different methods. Minerva  Stomatol. 2006;55(4):189.   6. Leclercq P, Zenati C, Amr S, Dohan D. Ultrasonic bone cut. Part  1: State-of-the-art technologies and common applications. J Oral  Maxillofac Surg. 2008;66(1):177-82.   7. Labanca M, Azzola F, Vinci R, Rodella LF. Piezoelectric surgery:  twenty years of use. Br J Oral Maxillofac Surg. 2008;46(4):265-9.   8. Schlee M, Steigmann M, Bratu E, Garg A. Piezosurgery: basics and  possibilities. Implant Dent. 2006; 15(4):334—-40.   9. Claire $, Lea SC, Walmsley AD. Characterisation of bone follow-  ing ultrasonic cutting. Clin Oral Invest. 2013;17(3):905-12.   10. Schaeren S, Jaquiery C, Heberer M, Tolnay M, Vercellotti T, Martin  I. Assessment of nerve damage using a novel ultrasonic device for  bone cutting. J Oral Maxillofac Surg. 2008;66:593-6.   11. Preti G, Martinasso G, Peirone B, et al. Cytokines and growth fac-  tors involved in the osseointegration of oral titanium implants posi-  tioned using piezoelectric bone surgery versus a drill technique: a  pilot study in minipigs. J Periodontol. 2007;78:716—22.   12. Leclercq P, Charlotte Z, Dohan DM. ultrasonic bone cut. Part 2:  State-of-the-art specific clinical applications. J Oral Maxillofac  Surg. 2008;66(1):183-8.   13. Beziat JL, Bera JC, Lavandier B, Gleizal A. Ultrasonic osteot-  omy as a new technique in craniomaxillofacial surgery. Int J Oral  Maxillofac Surg. 2007;36:493-S00.   14. Sivolella B, Bressan DF, Stellini E. Osteotomy for lower third molar  germectomy: randomized prospective crossover clinical study com-  paring piezosurgery and conventional rotatory osteotomy. J Oral  Maxillofac Surg. 2011;69(6):E15—23.    Gomez J, Sanchez R, Ferrer R, Duran-Sindreu F. Safety concerns  of piezoelectric units in implantable cardioverter defibrillator. J  Oral Maxillofac Surg. 2017;76(2):273-7.   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Bone lid technique with  piezosurgery to preserve inferior alveolar nerve. Oral Surg Oral  Med Oral Path Oral Rad Endodontol. 2009;108(6):E1-—S.    Open Access This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.  org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropri-  ate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.   The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in  a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.   The anatomy of the oral and facial region is complex, having  many vital organs and structures, including an intricate net-  work of blood vessels and nerves as well as the brain, eyes,  nose, and vital teeth. Plain radiography can be used for  screening because of its simplicity, but it cannot characterize  detailed anatomical relationships. Currently, imaging diag-  nosis must be performed with computed tomography (CT)  and/or magnetic resonance imaging (MRI) before surgery to  characterize the surgical area and surrounding anatomical  structures. Recent developments in imaging technology have  allowed for rapid processing and visualization of significant  amounts of data yielded from a variety of digital imaging  modalities. Prerequisites have been established for three-  dimensional (3D) visualization as well as programs for the  computer-assisted 3D planning of surgical procedures, and  these image sources are now available to assist the surgeon in  the operating room [1].   Today, surgeons can use computer-aided design and  computer-aided modeling (CAD/CAM) software to assist  with the planning and implementation of complex maxillofa-  cial surgical procedures [2]. CAD/CAM software allows the  clinician to import two-dimensional (2D) CT data in DICOM  format (Digital Imaging and Communications in Medicine)  to a computer workstation and create accurate 3D represen-  tations of the facial skeleton and related soft tissues. The data  can then be used either to print a stereolithographic (STL)  model or for virtual manipulation of the generated 3D model  by segmentation, reflection (mirroring), insertion, or  repositioning of 3D objects for treatment planning [3].    S. Sukegawa  Division of Oral and Maxillofacial Surgery, Kagawa Prefectural  Central Hospital, Takamatsu, Kagawa, Japan    T. Kanno (  Department of Oral and Maxillofacial Surgery, Shimane University  Faculty of Medicine, Izumo, Shimane, Japan    © The Association of Oral and Maxillofacial Surgeons of India 2021    Stereolithographic 3D models are useful for maxillo-  mandibular reconstruction indicators such as    Not only are they useful in visualizing and planning, but also  for providing haptic support to the surgeon for perceived excel-  lent tactile feedback during virtual surgery. They also prove to  be very useful in creating a more predictable workflow for the  intended surgical intervention. Unfortunately, there is no single  prediction method where the surgical plan as performed on the  model can be directly transferred to the patient.    Computer-assisted surgery (CAS) uses data from  image processing, and can be divided into two major  categories:    Computer-assisted presurgical planning involves preop-  erative surgical simulation using physical or virtual 3D  images or models, and helps the surgeon to appreciate the  underlying skeletal anatomy in a more precise manner. The  application of preoperative surgical simulations is being  used in the field of dental implantology for determining the  appropriate positions and sizes of implants as well as evalu-    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1 -15-1346-6_41    ating and planning for bone augmentation when needed,  and in the field orthognathic surgery for assessing the  amount and direction of movement of the jaws.   The process of intraoperative navigation was developed to  improve the sequence of “diagnosis-surgical planning-  surgery,” allowing surgeons to accurately visualize the posi-  tions of surgical instruments and guides in real time on a  display of patient CT and/or MRI data. Intraoperative navi-  gation systems integrate diagnostic imaging with the actual  surgical field, allowing simultaneous visualization of the sur-  gical site and the analogous image counterpart with the help  of a sensor that enables more precise access and manipula-  tion for areas with sensitive anatomy. These navigation sys-  tems have now evolved greatly to minimize invasiveness  while improving accuracy. The development of intraopera-  tive navigation surgery has enabled improvement in execu-  tion and predictability for greater precision during  oral-maxillofacial surgery.   This section presents an overview of currently available  navigation systems and their applications, focusing on clini-  cal utility and solutions they offer for problems and chal-  lenges in the field of oral and maxillofacial surgery.    “Navigation-assisted surgery” is a broad term and can be  interpreted in various ways.    Fig. 41.1 Components of a  surgical navigation system. A  surgical navigation system is  comparable to a global  positioning system (GPS) as  is commonly used in  automobiles, and is composed  of three primary components:  a localizer, which is  analogous to a satellite in  space; an instrument or  surgical probe, which  represents the track waves  emitted by the GPS unit in the  vehicle; and a CT scan data  set, which is analogous to a  road map    This is most usefully represented by three questions:  “Where is the anatomical target in our patient?”, “How  can we reach our target safely for our patient?”, and  “What is our current anatomical location?”.    Besides these questions, navigation-assisted surgery may  also be used as an “information center” to provide surgeons  with accurate and efficiently retrievable information.  Navigation systems used for surgery are very similar to a  global positioning system (GPS), as is commonly found in  automobiles.    It comprises three principal components: (1) a local-  izer, which is analogous to a satellite; (2) a “hand-held”  probe, which corresponds to the track waves emitted by  the GPS unit; and (3) the CT scan data of the patient,  which is analogous to a road map.    Intraoperative navigation systems were initially  developed for use in neurosurgery, but they are now  commonly used in surgery of the craniomaxillofacial  region due to their high accuracy and reliability [1, 4]  (Fig. 41.1).    Two main technologies are currently available for intraoper-  ative navigation, including optical and electromagnetic  (Fig. 41.2), and they share the same function. However, they  use very different technologies to relay position information  to the surgeon. Two major components of the optical naviga-  tion system are measured using an infrared camera. These  include the position of the reference frame, which is the opti-  cal point of reference for navigation and is also called the  patient tracker, and a surgical probe with light reflectors.  This enables the position of the surgical probe to be dis-  played on the CT or MRI image in real time. Care should be  taken to ensure that both the tracker and the probe are  detected by the infrared camera of the navigation system to  track the instrument position within the surgical field [5]. By  contrast, the electromagnetic system utilizes electromagnetic  fields and reference points on a patient borne device, along  with a wired instrument for the surgeon to manipulate within  the surgical field. The system functions by creating a mag-  netic field of known intensity and then using microsensors in  key instruments to allow the system to determine where the  instrument is located relative to the patient’s anatomy [6]. In  contrast to an optical system, an electromagnetic system  does not require a clear line of vision between the IR camera  and the sensors, allowing equipment and objects to be placed  between the sensors and the IR camera. However, the accu-  racy of this system is compromised when using ferromag-  netic instruments.    Registration is the task of obtaining the mutual transfor-  mation matrix by calculating the relationship between the  coordinates of the actual patient space and the coordinates  of the medical image. In other words, this procedure  involves the alignment of the patient and the image, and it  is the most important process when performing surgical  navigation.    Registration techniques are categorized into two  major types: (1) marker-based [7] and (2) marker-  free [8] (Fig. 41.3).    In the marker-based technique, registration requires iden-  tifiable markers to be placed within preoperative images that  can be easily detected on the patient during the surgery.  These markers include dental splints [9], skin adhesive refer-  ence markers, and bone-implanted screws [10]. In contrast,  the marker-free technique is based on the patient’s regional  anatomy. This can be performed by registering easily identi-  fiable soft tissue or bony structures on the patient’s preopera-  tive scans. Another technique for marker-free registration is  laser surface scanning, which is used to match random points  on the surface of facial skin to corresponding points on CT or  MRI images. More recently, hybrid registration combining  methods have been used that combine point registration and  surface registration [11].    Fig. 41.2 There are two main types of navigation systems currently available: (a) optical and (b) electromagnetic systems    Fig. 41.3 Registration techniques for navigation preparation can be  categorized into two main groups: marker-based and marker-free.  Marker-based registration requires markers that are apparent on preop-  erative images and that are easily detectable on the patient during the  procedure, such as (a) skin adhesive reference markers or (b) a refer-  encing dental splint (c) Marker-free registration relies on the patient’s    41.2.3.1 Application to the Maxilla and Midface  The use of navigation systems significantly improves the  degree of intraoperative precision and accuracy that can be  predictably transferred from the planning stages to the actual  surgery. However, navigational accuracy is limited by the  type of system used, the method of procuring imaging data,  and the intraoperative synchronization of the imaging data  with the patient’s actual position. The systems currently in  use for maxillary and midface surgery are relatively reliable,  as most have been modified from their neurosurgical coun-  terparts [12]. Because the maxilla and midface are immov-  able, unlike the mandible, the position of the skull relative to  the reference is stable, and the registration procedure directly  reflects this. Therefore, navigation-assisted surgery is the  best option at the maxilla and midface.   The use of navigation systems is not currently approved for  mandibular surgery. This is due to the nature of the mandible  to move on its joint (Fig. 41.4), resulting in the registration  not being reflected accurately in the navigation of the man-  dible. However, it may be possible if the position of the man-  dible is held identical to its intraoperative position during  image acquisition.   At present, solutions exist for the application of navigation  systems to mandibular surgery. One such option is the use of  a dynamic reference frame mounted to the mandible that  enables the continuous tracking of mandibular movement  during surgery [13]. This method utilizes a sensor frame and  mandible/teeth supported markers for the direct tracking of  the mandible during surgery. This permits free intraoperative    craniomaxillofacial anatomy. Laser surface scanning is applied in a dis-  tinct marker-free registration technique, where random points on the  facial skin surface are matched to corresponding points on the soft tis-  sues in preoperative computed tomography/magnetic resonance imag-  ing (CT/MRI) images    movement of the mandible. The second option is to maintain  an immobile intercuspation position, such as using a maxilla-  mandibular fixation to maintain intraoperative synchroniza-  tion [14]. Unfortunately, this is impossible to achieve in most  intraoral procedures. Therefore, a third strategy has been  developed in which the mandible is placed in a reproducible  position against the maxilla using an occlusal splint. This  method appears to produce no additional error.    There are numerous clinical applications for CAS and intra-  operative navigation in oral and maxillofacial surgery. This  is reiterated by literature support available over the last  decade supporting its use.    Computer-based surgery is a rapidly emerging approach  used in some surgical disciplines, and can be used both as a  research tool and to improve healthcare. Computer-based  surgery, in combination with the use of a navigation system,  has been shown to reduce overall operation time in complex  anatomic areas, such as maxillofacial trauma surgery (e.g.,  orbital trauma reconstruction surgery), making surgery more  reliable. Using 3D models based on CAS is suitable for pre-  operative preparation of reconstruction material for bone  defects caused by trauma. On the other hand, navigation sur-  gery is most suitable for intraoperative anatomical evaluation  [15]. By combining these techniques, safer and minimally    Fig. 41.4 The positional relationship between the reference and the  target becomes unstable due to the free mobility of the mandible. If the  mandible were maintained in an identical position during image acqui-    invasive surgery is possible. Maxillofacial trauma may be an  important indicator suggesting the use of navigation systems  (Figs. 41.5, 41.6, 41.7 and 41.8). Unilateral midfacial and  orbital trauma surgery may also be indicators, and are nor-  mally treated with open reduction and fixation with naviga-  tion assistance.   The largest sample sizes for navigation surgery were  found in the field of craniomaxillofacial trauma, offering sig-  nificant positive results for orbital fracture treatment through  navigation-assisted surgery. Midfacial trauma, and particu-  larly unilateral midfacial trauma, was most common exam-  ple of maxillofacial trauma available in the literature. Some  of these reports described the treatment of patients with  delayed zygomatic fractures requiring osteotomies to reposi-  tion the abnormally healed bones. This results in added com-  plexity for the surgeon due to the lack of known anatomical  landmarks. He et al. presented a protocol for the creation of  artificial landmarks on the surface of the zygoma [16]. The  technique involved the registration being performed with rig-  idly fixed, light-reflecting spheres placed on the patient’s  skull. Subsequent soft tissue surface scanning was performed  using a laser pointer to complete the process.   Another challenging facet of oral and maxillofacial sur-  gery is the management of orbital fractures. This can prove    sition and the surgical procedure, then all structures within the image  could be fixed in an identical position, thereby ensuring the accuracy of  the navigation surgery    to be demanding even for the most experienced of surgeons.  Literature indicates that intraoperative navigation is a very  useful tool in post-traumatic orbital reconstruction. Another  rising trend is the use of patient-specific implants (PSIs). A  recently published literature also discusses the use of PSIs  with navigation guidance [17]. A control group was treated  with navigation using prebent titanium mesh. Several signifi-  cant factors were reported favoring the study group. PSIs are  poised to make a significant change in the management of  orbital trauma.   Innovations such as intraoperative navigation and  computer-assisted surgical planning have been shown to  improve the efficacy, accuracy, and predictability of surgi-  cal procedures. The 3D reconstruction abilities of soft-  ware could be used to virtually display the patient’s  anatomy throughout the case, allowing for stereotactic  navigation. During the surgery, the intraoperative naviga-  tion system helps surgeons to control the positions of  implants or of repositioned bone, and assists in verifying  the final location. A navigation system enhances the sur-  geon’s ability to measure the extent of resection and to  confirm the orientation of bone grafts used for reconstruc-  tion. Using this approach, it is possible to minimize the  human error factor by increasing the adherence to a pre-    Fig.41.5 A 17-year-old male undergoing a large orbital floor to medial _tive/bioresorbable materials, the SuperFIXORB-MX®  orbital fracture reconstruction. Surgeons first created a three- (OsteotransMS®) system; TEIJIN Medical Technologies Co., Ltd,  dimensional model that was mirrored by CAS, and determined the Osaka, Japan, according to the shape of the orbits to be reconstructed  angle and form of reconstruction material using third-generation bioac-    Fig.41.6 (a-h) A 17-year-old male undergoing a large orbital floor to CAS was positioned at the reconstruction site. We then confirmed the  medial orbital fracture reconstruction. Navigation will determine the exact position of the reconstruction material and reconstructed the  exact intraoperative anatomical form. Reconstruction material before orbital shape using the navigation system    Fig. 41.7 (a) The bioresorbable mesh plate was positioned to support  the orbital globe. (b) The reconstructed site was confirmed to match the  mirror image using a tip pointer with a navigation system. (c)  Intraoperative navigation system screenshot showing a multiplane view    of the position of the surgeon’s navigation probe in relation to the  orbital floor defect region at the time of localization. (d) Shows the  reconstruction plan image, created using the mirroring technique    Fig.41.8 (a, b) A 33-year-old male undergoing a nasoorbitoethmoidal  (NOE) and maxillary fractures open treatment, including a large orbital  floor to medial orbital walls fractures reconstruction. We, maxillofacial  surgeons, first created a three-dimensional (3D) precise preorbit to  orbital groove model that was mirrored by computer-assisted simula-  tion, and determined the anatomical form of reconstruction for autoge-  nous bone harvested from calvaria using Piezosurgery® according to  the 3D shape of the orbits to be reconstructed (produced by Yasojima  Proceed Co., Ltd. Osaka, Japan). Navigation will determine the exact    intraoperative 3D anatomical form. (c) The fractured deep medial  orbital wall was precisely reduced under an endoscopic-assisted  navigation-guided surgery by otorhinolaryngology-head and neck sur-  geons. (d, e) We then reconstructed the large orbital floor and confirmed  the exact position of the autogenous calvarial bone for accurate recon-  struction of the orbit using the navigation system, followed by fixation  using titanium screws. (f) The use of intraoperative CT in the hybrid  operation room can provide rapid CT data during surgery for the final  3D confirmation of complex orbital reconstruction cases    operative plan. Furthermore, this also helps in reducing  the incidence of postoperative complications due to  improperly positioned or oriented bone grafts, plates, or  fixation screws. Virtual surgical planning (VSP) combined  with 3D printing technology has improved surgical effi-  ciency and precision through the generation of 3D surgi-  cal models, implants, and guides [18]. This increases the  number of indicators suggesting the use of VSP by the  surgeon, as it offers additional tools in preoperative plan-  ning and intraoperative decision making. Both VSP and  3D models may be used to plan the optimal reconstruction  material in terms of the volume, shape, and dimensions  required. They can also be used to produce templates for  resective surgery to accurately demarcate the boundaries  for resection and/or to plan more efficient and accurate  reconstructive strategies. A further advantage of using 3D  models is a reduction in total operative time and the elimi-  nation of potential complications from prolonged  surgery.    Fig. 41.9 A 79-year-old male with recurrent ameloblastoma of  maxilla-infratemporal fossa. Because of the complexity of the local  anatomy, tumors in the infratemporal fossa present a challenge to oral  and maxillofacial surgeons. Recurrent malignant tumors in this area are  particularly difficult to resect because scars from previous operations    Computer-assisted navigational surgery is a proven method  for reducing operating time and increasing reliability in com-  plex surgical procedures of the infratemporal fossa and the  periorbital region [19] (Fig. 41.9). Navigation-assisted sur-  gery was introduced in the field of oral, head, and neck tumors  more than 20 years ago. The use of navigation in the manage-  ment of benign and malignant lesions is discussed later.  Malignant lesions of the head and neck have a high rate of  recurrence (25—48%). Tumor control essentially depends on  the extent of the tumor, its location, and the margins of resec-  tion, with the latter being a very important prognostic factor  in cancer surgery. Feichtinger et al. [20] used navigation sys-  tems to evaluate the resection margins in the treatment of six  patients with carcinomas in the nasal cavity, maxillary sinus,  and oral cavity. In four patients, further resection had to be  performed after an assessment with a navigation system    may dislocate important structures. A navigation technique has been  introduced to resect infratemporal fossa tumors and was successfully  applied for the resection of recurrent malignant tumors. The visible  navigation during surgery could increase the accuracy and safety of the  operations and enhance surgeon confidence    using positron emission tomography (PET)-CT scans proved  the initial resection to be unsatisfactory. This demonstrates  that navigation surgery based on PET-CT image fusion is an  excellent tool for improving the local control of advanced  head and neck cancer.   Navigation-assisted surgery has also been successfully  used in the management of benign tumors of the maxillofa-  cial region [21]. This was performed with features such as  mirroring and side-to-side comparisons, and was applied  with successful results. Use of customized hydroxy-apatite  prosthesis with pre-embedded titanium implants was used  for reconstruction. Optimal positioning is secured using nav-  igation. Some interesting techniques for reconstruction are  discussed now.   It is important to remember that navigation is an excellent  tool when it comes to its use in the skull base [22], the mid-  face [23], and the neck [24]. However, its use in mandibular    Fig. 41.10 Optimal treatment planning and preparation using 3D  models. CAS for cleft lip and palate-related severe maxillary hypopla-  sia deformity patients using maxillary distraction osteogenesis. (a—c) A  17 year old male undergoing maxillary distraction for cleft-related mid-  facial retrusion. (d) Detailed computer simulation for maxillary distrac-    tumors is limited due to the possibility of changes in the spa-  tial orientation of the lower jaw, as described earlier.    The primary determinants of success in orthognathic surgery  include an accurate diagnosis, meticulous treatment planning,  and the ability to transfer the plan precisely to the patient  intraoperatively. In earlier years, this was performed by a  process of model surgery in a laboratory using articulators  on plaster casts, which were then transferred to the patient  using acrylic splints during the surgical procedure  (Figs. 41.10 and 41.11). The procedure was error prone at  multiple levels within the sequence. Literature reports an  error of up to 5 mm using this type of treatment sequence.  With the advent and routine usage of CAD/CAM technology    tion surgery in a patient with severe maxillary hypoplasia deformity  was used to determine the optimal treatment plan, such as the distrac-  tion direction and degree of advancement. (e, f) A 3D printed skeletal  model was used to prepare for a maxillary semi-custom-made distractor  setting with fabrication    Fig. 41.11 A 17-year-old male undergoing maxillary distraction for  cleft-related midfacial retrusion. (a—d) Accurate transfer of the treatment  plan to the patient in the operating room was acheived. Using the naviga-  tion system, precise placement of the maxillary distraction planned pre-    and virtual surgical planning, the workflow of treatment  planning in orthognathic surgery has undergone a paradigm  shift. The conventional workflow of model surgery and splint  fabrications is slowly paving the way for VSP and custom  printed 3D splints and guides.   Although the degree of inaccuracies associated with treat-  ment planning is reduced using this approach, certain draw-  backs such as autorotation of the mandible and lack of  control on the vertical position of the maxilla are still  prevalent.    There are three methods by which CAS is used in the  practice of orthognathic surgery: (1) using real-time  intraoperative guidance with surgical navigation for  the repositioning of the maxilla and mandible; (2) use  of 3D printed cutting guides for precise osteotomy and  repositioning, with or without customized 3D printed  osteosynthesis plates; and (3) the use of wafer-less sur-  gical planning where the printed implant doubles as  both a cutting guide for the osteotomy and as the fixa-  tion devices. Many clinical studies have evaluated the  efficacy of these methods with promising results.    Mazzoni et al. were the first to report the use of intraop-  erative navigation in orthognathic surgery, in 2010 [25].  They calculated the overlap error to assess the accuracy of    operatively at the set position was performed. The surgeon then confirmed  the same distraction direction that was preoperatively planned by the  intraoperative navigation. (e-g) Shows the radiographs during and post  treatment. (h) Shows the final post surgical result of the patient    the technique after surface matching the virtually planned  model and the postoperative CT scan. The accuracy was  reported for the entire facial skeleton, rather than for each  component individually (maxilla, mandible, chin), with a  mean match error for each patient ranging from 0.28 to  1.99 mm. Repeatability (<2 mm) in the face area ranged  from 77.5% to 96.2% between patients, with a mean repro-  ducibility of 86.5%.   Zinser et al. published a clinical controlled trial study in  2013 that compared the navigation technique with conven-  tional technique, using 3D surgical guides and intermaxil-  lary splints [26]. The highest accuracy for transfer of the  maxillary plan to the patient was observed when a 3D sur-  gical guide was used, and no significant linear differences  between the planned virtual model and the postoperative  results were present in any direction. The navigation tech-  nique only showed a significant mean linear difference in  the vertical dimension, and differences in angulation were  not significant in either group. In contrast, significant linear  differences were shown for the classic intermaxillary  splints between the planning results and the actual results  in the sagittal and vertical dimensions. Differences in plane  angulations when using an interocclusal splint were also  significant. The usefulness of navigation-assisted surgery  for orthognathic surgery was supported based on previous  reports.   Published literature demonstrates that all studies have met  the 2-mm success criterion, which refers to a maximum dif-  ference of 2 mm between the virtual planning performed and    the actual surgical outcome. Zinser et al. reported the only  prospective controlled clinical trial comparing CAD-CAM  splints, navigation surgery, and intermaxillary splints for the  transfer of maxillary planning [26]. The CAD-CAM splints,  patented by the authors, were used for maintaining the man-  dibular condyles (TMJ) in their centric relation. Mandibular  positioning still poses a challenge during orthognathic sur-  gery, with none of the solutions having attained “gold-  standard” status.   An important clinical limitation for the use of navigation  is the increase in operating time [27]. Though there is ample  support for increased accuracy levels with the use of naviga-  tion, the prolonged operating time still remains a deterrent  for the routine use of intraoperative navigation in orthogna-  thic surgery. A recent study indicates that dynamic naviga-  tion systems have an entry error of approximately 0.4 mm  [28] and an angular deviation error of approximately 4° [29].  Further technological developments can be expected in the  field of orthognathic surgery, and an appropriate update for  surgeons is required.    Loss of teeth and supporting structures is a common occur-  rence in the field of oral and maxillofacial surgery for patients  who have suffered extensive alveolar bone defects caused by  cysts, tumors, facial trauma, or severe periodontal disease  [30]. Comprehensive reconstruction methods, including  rehabilitation with multiple dental implants, are commonly  required to restore function in these patients.   Issues like atrophic jaws, where dental implants cannot be  placed due to the loss of bone corpus, are managed by regen-  erative procedures. Although bone augmentation at the man-  dibular posterior areais important for occlusion reconstruction  using dental implants, it is difficult due to anatomical limita-  tions arising from the inferior alveolar nerve (IAN) and the  mandibular bone. However, bone augmentation at the man-  dibular posterior area can be performed safely and reliably  using CAS with 3D modeling and navigation systems  (Figs. 41.12 and 41.13).    Fig. 41.12 (a—d) Computer simulation based on preoperative CT data  will determine the bone augmentation method for implantation. In this  case, we chose bone augmentation using the sandwich technique. The  necessary bone augmentation volume and position of the anatomically    important inferior alveolar nerve (IAN) were confirmed using computer  simulation. Based on this information, we will determine a safe bone  cutting line. Surgeons then created a surgical guide using a 3D model  based on simulation    Fig. 41.13 (a—d) This is a continuation of Fig. 41.12. While confirm-  ing the position of the IAN in real time based on intraoperative naviga-  tion, the surgeon cut the alveolar bone with reference to the surgical  guide created before surgery. (e) The surgeon then inserted autologous    Traditionally, implants have been placed freehand or with  the use of laboratory-fabricated guidance stents. The use of  CT-guided 3D printed stents with coordinated drill sequenc-  ing has minimized errors to a level of less than 2 mm for  crestal and apical deviations, and to less than 5° in angula-  tions. Dynamic navigation systems use a time-effective  method to accurately place implants with equivalent implant  placement error. Currently the Image-Guided Implantology  system (Navident; HERMANS Corp., Tokyo, Japan) is the  only dynamic image navigation system (DINS) available for  in-office dental procedures in Japan. Its counterpart in the  United States is the passive optical dynamic navigation in  implantology (X-Nav Technologies, Inc., Lansdale, PA,  USA).    Navigation in dental implantology can add the follow-  ing advantages: (1) precise depth control and reduced  risk of IAN damage [31]; (2) help in planning for flap-  less surgery or limited flap elevation surgery with  reduced postoperative morbidity [32]; and (3) accurate  spacing and implant angulation compared to using a  freehand approach.    The use of virtual implant planning and intraoperative  navigation allows for prosthodontic and surgical coordina-  tion due to its planning accuracy and implementation in  actual surgical scenarios.    bone taken from the donor and increased the alveolar bone vertically.  The most important goal in this surgery is to acquire alveolar bone  height as planned before surgery. (f) The bone height can be confirmed  in real time based on intraoperative navigation    Dynamic navigation methods have similar advantages,  including high accuracy, time- and cost-effectiveness, mini-  mally invasive techniques, and flexibility in changing the  implant size, system, and location during the surgical proce-  dure [33]. An additional advantage is comfort provided the  surgeon in the form of posture, facilitating reduced bending  of the neck and back. For example, dynamic navigation  allows implant placement for patients with a limited mouth  opening, or requiring an implant at a second molar site with  reduced access, by relying on a navigation screen to guide  the drill sequence without direct visualization of the patient’s  mouth.    Retrieval of foreign bodies in the craniomaxillofacial region  is often extremely dangerous due to the proximity to various  vital structures within a limited anatomical space [34]. This  may be made more complex by the presence of deep foreign  bodies secondary to severe trauma such as gunshot wounds  or blast injuries, which significantly alter the anatomy.  Precise location of the foreign body is the first step in the  retrieval process, and this may be accomplished with preop-  erative scans and 3D image rendering. The intraoperative  step is next, and is more challenging, as the exact location of  the foreign body within the surgical field must be ascer-  tained. Traditional methods utilize a stereotactic “double  needle” method with venipuncture needles for triangulation    Fig.41.14 (a—g) A 65-year-old female with a foreign body due to den-  tal instrument breakage in the mandible, occurring during an endodon-  tic treatment for a restorative dental procedure. (a, b) Fracture of root  canal instruments, with a fractured piece protruding beyond the apex, is  a troublesome incident during endodontic treatment. Locating and  retrieving these objects represents a challenge for maxillofacial sur-  geons because they are difficult to access due to the proximity between  the foreign body and vital structures. Using the navigation system for  mandible treatment is difficult as the mobile nature of the mandible  complicates its synchronization with the preoperative imaging data dur-  ing surgery. (c) The broken dental instrument was removed using a    of the foreign body using plain radiographs [35]. This  involved the two reference needles being sequentially placed  until both met the foreign body on radiographs. Through  blunt dissection, one of the needles is made to contact the  foreign body and locate it. It is important to understand that  it may be difficult to distinguish small changes in position on  plain radiographs. The use of C-arm digital fluoroscopy was  a significant advancement for this method, providing rapid  radiography [36]. However, as with plain films, fluoroscopic  images are 2D, which imposes limitations when locating    minimally invasive approach with a surgical navigation system and an  interocclusal splint for stable, identically repeatable positioning of the  mandible. (d, e) Based on the 3D position of the navigation probe, a  location that best approximated and the most anterior extent of the frag-  ment was selected. (f) A minimal vestibular incision was made at this  location, a subperiosteal reflection was performed, and the foreign body  location was confirmed using the navigation system. (g) The instrument  was carefully visualized and extruded from the apical to the tooth  crown side and was then removed using mosquito forceps through the  medullary cavity of the crown side of the tooth    objects in a 3D space. The use of intraoperative ultrasound  imaging has also been proposed to localize foreign bodies.  However, the precision involved in positioning may be ques-  tionable, and its use in the oral cavity may also be limited by  the size of the instrument.   Intraoperative navigation systems could allow a foreign  body to be accurately located in 3D space; these systems are  very effective for removing a foreign body during facial sur-  gery [37] (Figs. 41.14 and 41.15). One limitation of naviga-  tion is the incapability of the system to account for    Fig.41.15 A 78-year-old female with a small foreign body in the max-  illa. Accurate determination of the position of the foreign body in the  maxillofacial region can be challenging. This may be due to a small-  sized foreign body or a limited inflammatory response. Navigation sys-  tems are helpful in identifying the location of the foreign body,  determining the optimal approach, and performing the surgical proce-    intraoperative soft-tissue changes. The use of navigation  techniques superficial tissues or to minimize soft-tissue  manipulation may help us overcome this to an extent.    Dynamic computer-based image navigation technology is  a good method for increasing accuracy while minimizing  the invasiveness of surgery. It has the additional advan-  tage of real-time access to intraoperative radiographs,  which enable us to perform complex dentoalveolar pro-  cedures with relative ease. Currently, the Image-Guided  Implantology system (Navident; HERMANS Corp.) is  the only dynamic image navigation system (DINS) avail-  able for in-office dental procedures in Japan. This is an  ultraviolet-based optical system, which was approved by  the US Food and Drug Administration for the placement  of dental implants. However, its use for other dentoalveo-  lar procedures is not approved. Its advantages in the field  of dental implantology have already been discussed ear-  lier. The use of dynamic navigation when applied to com-  plex dentoalveolar procedures, such as the surgical  removal of third molars, is similar to its use for dental    dure using a minimally invasive surgical strategy. In this case, registra-  tion could be reliably performed before surgery using an optical  navigation system that facilitates the process, utilizing splints with  embedded reference points. This method can decrease the operation  time    implants, helping the surgeon prevent inadvertent dam-  age to key structures like the IAN, roots of adjacent teeth,  or the lingual plate of the mandible [38]. Common indi-  cations for the use of navigation in dentoalveolar surgery  include third molar extractions and the location and  extraction of supernumerary [39] or malposed teeth  (Fig. 41.16), as well as teeth, which get iatrogenically  displaced into the sinus, the sublingual pouch, or even the  infra temporal fossa.   The use of CAS in oral and maxillofacial surgery has  been enhanced with the increasing availability of  CBCT. This in turn has promoted the use of Dynamic  Image Navigation. As described earlier, the use of DINS  during surgical extraction improves visualization of the  regional anatomy, preventing or minimizing complications  secondary to dentoalveolar surgery. In addition, improved  instrument control allows for reduced bone removal, mini-  mization of the surgical access size, and an overall reduc-  tion in the morbidity of the procedure. As discussed earlier,  this technology also allows for improvement of the ergo-  nomics involved during the surgery. Lastly, dynamic guid-  ance can serve as an effective teaching tool for young  surgeons by displaying the surgery and the locations of  vital structures on screen.    Fig. 41.16 (a-i) A 24-year-old female with an impacted maxillary  canine tooth. Bone lid surgery involves cutting a window into the cortical  bone and removing a portion thereof; this portion is subsequently returned  to its original position at the end of surgery. Bone lid surgery is a mini-  mally invasive technique designed to avoid secondary large bone defects  during osteotomies. However, because jaw bone lesions are completely  covered with cortical bone, it can be difficult to accurately determine the  position of the lesion from the outside. As a potential solution, we used  navigation-assisted bone lid surgery. Using navigation, surgeons could    Wang reported the following advantages of surgical  navigation in complicated extractions: (1) localiza-  tion of teeth for accurate access planning and mini-  mal bone removal; (2) differentiation of impacted  teeth from erupting tooth germs; (3) ensured transfer  of the preoperative plan to the surgical procedure;  and (4) the marking of safety margins while preserv-  ing adjacent structures, to avoid complications [40].    confirm the state of the impacted tooth and surrounding tissue from above  the covered bone. We were also able to establish a safe and reliable bone  cutting line. In addition, the removed cortical bone was returned to the  same (1.e., presurgical) position. Navigation-assisted bone lid surgery for  the removal of impacted teeth increases surgical accuracy, minimizes  invasion, and allows the bone to be returned to its original position  (a, b)-pre operative OPG and CT (c—e)-shows intra operative navigation.  (f) outline of canine marked (g, h) impacted canine being removed (i) the  bone lid placed back in position    The TMJ and surrounding anatomy, including the skull base,  are extremely complex and require a cautious approach dur-  ing surgery. Intraoperative navigation can play an important  role for surgeries such as the removal of an ankylotic bony  mass, tumor resection, and gap arthroplasty [41]. Successful  treatment outcomes have been reported by studies for the use    of navigation assistance in unilateral surgery for the  TMJ. Other publications report that navigation is helpful and  increases safety in TMJ surgery. A recent publication used  navigation to compare prospectively treated groups of  patients with recurrent malignant tumors of the infratempo-  ral fossa. Although the results are not independently signifi-  cant, they yielded a benefit to the navigation cohort. The  authors concluded that surgeon confidence and safety during  the operations improved, but the navigation system alone did  not determine patient outcomes.   Management of tumors at the skull base or of end-stage  degenerative TMJ disorders requires thorough knowledge of  the regional anatomy and precise 3D planning of the resec-  tion margins with attention of vital structures in the immedi-  ate vicinity (Fig. 41.17). The location, invasion, and extent of  the tumor are key determinants in deciding the surgical  approach. In the past, malignant tumors that had infiltrated  into the infratemporal fossa or the middle of the skull base  were considered inoperable due to the compromised access  and inability to achieve predictable tumor control or  hemostasis.   The use of surgical navigation for skull base surgery  offers the following advantages: (1) ensuring safer and  quicker skull base access through a dynamic display of the  precise operating site and the extent of bone drilling, thereby  significantly reducing intraoperative risk; (2) mapping the  anatomical structures and important landmarks such as the  foramen ovale and rotundum; and (3) the incorporation of  allied imaging modalities, such as 3D CT angiography and  MRI, into the intraoperative navigation planning, increasing  our understanding of the skull base anatomy and the internal  carotid artery region.   As surgery of the skull base is not affected by the shifting  brain, use of navigation in this field is more precise than in  other neurosurgical procedures. The use of a navigation sys-  tem for the resection of tumors of the skull base or of TMJ  lesions increases surgical predictability while reducing the  surgical duration.    Another application of intraoperative navigation is in surgery  for the management of Eagle’s syndrome, which may be due to  the elongation of the styloid process of calcification of the sty-  lomandibular ligament [42]. This condition involves a group of  symptoms, including throat pain and foreign body sensation on    the affected side, reflex otalgia, head and neck pain, and hyper-  salivation. Surgical treatment was indicated for patients with no  symptomatic improvement following conservative treatment.   The surgery may be performed by two different  approaches: (1) transcervical and (2) transoral. The cervical  approach provides better surgical exposure of the area, but  has the major disadvantage of an external incision. The tran-  soral approach is cosmetically favorable, and is more  commonly used. However, this approach offers very limited  access. This may affect the management of intraoperative  complications, including hemorrhage or difficulty in identi-  fying the styloid process. Several methods have been advo-  cated recently to overcome these problems. One report  suggests an endoscopically assisted transoral approach for  achieving better exposure and visibility of the field. Another  method proposes a combination of piezoelectric surgery and  surgical navigation for a transcervical approach to remove  the styloid. This technique offers a safe and effective method  for the treatment of Eagle’s syndrome (Fig. 41.18).    The accuracy of surgical navigation in recent years has  been augmented by the induction of intraoperative imaging  modalities like the intraoperative CBCT, C-arm, and O-arm  systems [43]. These offer intraoperative multiplanar recon-  struction capabilities, which enable the improvement of  surgical outcomes in demanding surgeries such as surgery  of the orbital walls. Furthermore, the popularization of  hybrid operating rooms (Fig. 41.19) equipped with both  intraoperative imaging and navigation systems has revolu-  tionized surgery of the maxillofacial region. It is now pos-  sible to continuously update intraoperative images to  determine the best sequence to follow during surgeries  (Fig. 41.20). The effectiveness of a navigation system using  intraoperative CT images has been already demonstrated in  orthopedic surgery and maxillofacial operations, which  involve bone movement, such as trauma surgery and  orthognathic surgery. Intraoperative CT images have  allowed for rapid intraoperative evaluations, which when  coupled with surgical navigation, may allow for performing  more complicated maxillofacial surgery with increased  accuracy.    Fig.41.17 A 70-year-old female with temporomandibular joint (TMJ)  ankylosis. Ankylosis surgery is used for gap arthroplasty and mobiliza-  tion of the joints. (a-c) However, removal of the bony ankylosis and  creation of a gap between the ramus of the mandible and the base of the  skull can be difficult because of the size of the ankylosis and the anat-  omy on the inner aspect of the mandible. Virtual planning is useful in  conjunction with surgical navigation to remove the ankylosis. (d) First,  a computer simulation based on preoperative CT data was performed  for the virtual surgery. (e, f) Once the virtual surgery was completed,    templates were constructed using rapid prototyping techniques from the  virtual plan and applied at the time of surgery to facilitate the bony cuts.  (g, h) Using the intraoperative navigation system, the surgeon can see  the medial aspect of the mandible on the navigation station CT and  protect important structures on the medial side. (i) This visualization  prevents significant bleeding from the vessels on the medial side of the  mandible and prevents penetration into the middle cranial fossa during  release of the ankylosis. The temporalis flap was used for prevention of  reankylosis    Fig. 41.18 (a, b) A 45-year-old male with elongated styloid process  syndrome (Eagle’s syndrome). A minimally invasive approach with an  intraoperative navigation system was used. (c) Preoperative preparation  involved a custom interocclusal splint to produce the mouth opening  conditions required during surgery. In this case, since the transoral  approach was employed, it was important to reproduce the same mouth-  opening conditions when obtaining the preoperative images required  during surgery, because the position of the styloid process and the blood  vessels may change depending on the position of the mandible during  the mouth opening. Since it is difficult to implement the locational find-  ings from the preoperative imaging data while performing surgery  owing to the mobile nature of the mandible, a custom interocclusal  splint for repeated maximum opening in the same mandibular position,    Although intraoperative navigation yields helpful infor-  mation on anatomical features, it is used in conjunction    while enabling surgical access, was used. (d) The patient was taken to  the operating room, where the custom interocclusal splint was rein-  serted. (e) To perform patient-to-CT and MRI data registration, the  instrumentation navigation probe was used to trace the reference array  and soft tissue landmarks of the face. (f) Using the 3D position of the  navigation probe, the location of the elongated styloid process was  identified. (g, h) After confirmation of the resection location via the  transoral approach, the styloid process was dissected using piezoelec-  tric surgery. Follow-up examination showed an uneventful recovery  with no associated complications. (The resection of the styloid process  using an intraoperative navigation system and a custom interocclusal  splint during a transoral approach, together with a piezoelectric cutting  device, is safe and effective for the treatment of Eagle’s syndrome)    with a monitor. Generally, the direction of the monitor  from the surgeon and operator is different from that the  surgical field. Therefore, to see the navigation image, the  surgeon and the operator must look up, which is stressful  for the operator. It is important to minimize muscle ten-  sion and allow the surgeon to perform the operation in a    Fig.41.19 A hybrid operating room is a surgical theater equipped with  advanced medical imaging devices, such as fixed C-arm and angio-  graphic systems. Intraoperative CT imaging is convenient because the    relaxed position. Moving the head to look at the monitor  can result in considerable misalignment of the eye-hand-  target axis during task execution, significantly affecting  postural comfort and interventional safety. In recent  years, head-mounted display monitors have been devel-  oped to address this problem. Such wearable displays can  provide high-quality images [44]. Using a head-mounted  display monitor, surgeons can finish the surgery without  moving their head to check the navigation image. The  head-mounted device also allows both the surgeon and  the assistant to view both the navigation image and the  surgical field without interrupting the flow of surgery.  This contributes to rapid surgical operation, resulting in    CT is installed in the hybrid operating room. Furthermore, recent  advances in technology have made it possible to edit and use images  simultaneously with intraoperative CT imaging    minimally invasive surgery. Navigation-assisted surgery  with a head-mounted display is a revolutionary tech-  nique. In the future, head-mounted displays will be wear-  able devices that promote the use of navigation    CAS and navigation offers significant improvements in  patient orientation and safety in every facet of maxillofa-  cial surgery. Ranging from precisely planned orthognathic  procedures to the removal of foreign bodies requiring    Fig. 41.20 (a) A 19-year-old male with a complex facial fracture and  orbital fracture. Navigation surgery is difficult to apply for treating a  complex facial fracture with orbital fracture. (b) Since reconstruction of  the buttress of the facial bone is performed prior to the treatment of the  orbital fracture, preoperative CT data and the actual state of the facial  bone are different. Therefore, a navigation system using preoperative    extremely flexible surgical options, and from minimally  invasive dental implantology procedures to radical tumor  resections of the skull base, they have made their mark  improving procedure safety, predictability, and accuracy  of surgery while also improving options for intraoperative  adaptations. In the future, the application of CAS is  expected to further reduce operative risks and surgery    CT data cannot be employed. (c) Using CT data obtained after facial  fracture reduction, (d) it is possible to use a navigation system reflect-  ing the updated patient condition. The use of CT in the hybrid room can  provide rapid CT data during surgery. (e) The orbital floor defect has  been repaired. (f) Post operative CT showing the accurate reduction of  fractures   Navigation systems are effective for delicate and accurate  oral and maxillofacial surgery and neurosurgery, as well as  for otolaryngology and orthopedic surgery. In the future, we  expect to develop more convenient and reliable navigation  systems using new technologies and devices.    Fig. 41.21 The head-mounted display can provide high-quality  images with wearable technology. The head-mounted display unit was  composed of a head-mount image processor unit (HMM-3000MT;  Sony Corporation, Tokyo, Japan) and a head-mounted display monitor.  Although the navigation system provides helpful information, it is used  in conjunction with a monitor. Generally, the direction of the monitor  differs from the surgical field. Therefore, to see the navigation image,  the surgeon and the operator have to look up, which is stressful for the  operator. Using a head-mounted display monitor, we could finish sur-  gery without moving the head position. The surgeon must perform not    1. Sukegawa S, Kanno T, Furuki Y. Application of computer-assisted  navigation systems in oral and maxillofacial surgery. Jpn Dent Sci  Rev. 2018;54:139-49.   2. 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Takahashi Y, Masui M, Furuki Y. Use of an intraoperative navi-  gation system and piezoelectric surgery for styloidectomy in a  patient with Eagle’s syndrome: a case report. J Med Case Rep.  2017;11:322.   Wikner J, Riecke B, Grobe A, Heiland M, Hanken H. Imaging of the  midfacial and orbital trauma. Facial Plast Surg. 2014;30:528-36.  Matsuo A, Hamada H, Oba H, Shibata K. Virtual reality head-  mounted display for endoscopically-assisted implant surgery. Br J  Oral Maxillofac Surg. 2018;56:636-7.    Open Access This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.  org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropri-  ate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.   The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in  a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.    Human Factors Recognition to Enhance  Team Working and Safer Patient Care   Human error and organisational mistakes are a significant  cause of morbidity for patients. It is important to recognise  and address human factors (HF) in the context of our own  performance optimisation, enhancing team working to  improve patient safety, and better working lives for clinicians  across surgery and medicine.   Medical errors are usually multi-factorial rather than the  direct fault of any one individual. Organisational issues,  poor team working and other HF are often at the root of  many incidents and errors. The Surgical Checklist pro-  duced by the World Health Organization (WHO), and avia-  tion-styled communication training initiatives have been  advocated to optimise surgical performance by reducing  human fallibility and misinterpretation between team mem-  bers. Brief and debriefing processes and other performance  improvement practices have been positively rated when  incorporated into healthcare. Ergonomics and other factors  such as stress and fatigue, emotional status, hunger, dehy-  dration and situational awareness can all lead to human  error, but these are often under-appreciated and in some  cases even disregarded.   The aims of this chapter are to raise colleague awareness  of both individual human factors and those relevant to organ-  isations and to highlight relatively simple methods to actively  reduce error in healthcare.    P. A. Brennan   Maxillofacial Unit, Queen Alexandria Hospital, Portsmouth, UK  e-mail: peter.brennan @porthosp.nhs.uk    © The Association of Oral and Maxillofacial Surgeons of India 2021    Over 70% of plane crashes are due to a human mistake rather  than a failure of the aircraft itself. Issues with communica-  tion can occur in up to 80% of air disasters. Recognition of  factors leading to human error, including tiredness, stress,  and repetitive tasks, and an acceptance that a certain degree  of failure is almost inevitable, has improved air safety. These  factors are being increasingly recognised by healthcare pro-  fessionals [1]. The American Institute of Medicine report  entitled “To Err Is Human” published in 1999 and subse-  quent work has found death from preventable medical errors,  with those in surgery second only to medication errors as the  most common reasons for death from medical error [2].  Recent estimates place avoidable patient deaths in USA hos-  pitals at over 400,000 per year, with preventable harm in the  top three causes of death [3].   While the authors were not able to source any statistics  for the Indian sub-continent, death in UK hospitals from  medical error is estimated to be about 4000 per year, with a  disproportionate amount of harm caused by errors in surgery.  To put this into context, this would be the equivalent of more  than one A320 fatal airbus (Fig. 42.1) crashes occurring  twice a month. Incidentally, the A320 is the aircraft involved  in the widespread media coverage after an emergency land-  ing on the River Hudson in January 2009 by Captain ‘Sully’  Sullenerger, subsequently dramatized in the well-known  movie, Sully. Despite the WHO checklist, which is widely  used throughout the modern world, the number of ‘never  events’—those that should never happen, including wrong  site surgery and retained instruments or swabs—is increas-  ing [4]. Although doctor-induced mistakes are quite rare, a  near miss occurs far more commonly in the hospital environ-  ment. An investigation and detailed cause analysis following  any incident can help organisations learn, prevent and reduce  the chance of such errors occurring again in the future.    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1-15-1346-6_42    Fig. 42.1 The flight deck of an Airbus A320 being configured for  departure    Recognition and understanding of those relevant HF involved  in potential error is vital for improving patient safety. These  factors include fatigue and tiredness, stress, communication  style, effective team working, and good leadership. The well-  known ‘Swiss cheese model’ of error (Reason [5]) is illus-  trated in Fig. 42.2. Organisational failures contributing to  medical error could include pressures on individuals to meet  hospital targets, having too many patients on an operating  list than is deemed safe, too many patients in an outpatient  clinic, working very long hours without taking a break or  being expected to operate the following day after having  being disturbed overnight with on-call emergencies.    42.3.1 Senior Management Support Is  Essential in Helping to Reduce Medical  Error    Senior management commitment is essential in ensuring  safety across any organisation. An open culture has to be key  in any hospital agenda and strategy. Poor leadership together  with a ‘blame culture’ led to more than 35 deaths in the  Bristol paediatric cardiac surgery service. As a result, a large  number of changes were implemented to limit future pre-  ventable surgical incidents. Pilots, aircraft ground engineers  and other aviation safety staff are encouraged to actively  question any safety issues related to their aeroplane, and  their employer must investigate concerns, even if this means  stopping a flight from taking off. In healthcare, we should be  following this safety model with higher hospital manage-  ment and surgical team leaders creating a safe environment    Fig. 42.2 Schematic representation of the Swiss cheese model of  human error. Each of the cheese slices acts as a barrier to an error occur-  ring with the final chance for stopping the error being the elimination of  the unsafe act itself. Error has its origin in organisation influences (latent  failure) and those caused by individuals and teams (active failures)    ¢ Read out WHO Checklist with active participation of all team  members. Engage with it as if your own life or limb depended on  getting it right   ¢ Limit avoidable distractions and any interruptions during essential  parts of an operation (same as sterile cockpit in aviation).   ¢ Ensure 6-8 h of sleep, regular physical activity and adequate  nutrition and hydration before starting surgery.   ¢ Look out for each other as part of the team.   ¢ Ensure you take regular breaks and eat and drink often during the  day.   ¢ Do not assume physically uncomfortable postures unless absolutely  necessary. Adjust equipment, table for the comfort of you and your  team.   ¢ Special patient factors, e.g. Jehovah witness unable to accept  transfusion, obesity    to report and action possible error. The surgical team has to  endorse the use of evidence-based best practices, including  use of the WHO Surgical Checklist, avoiding human error  traps (Table 42.1) and early identification of those situations  in which harm or error is more likely to occur (Table 42.2).    42 Human Factors Recognition to Enhance Team Working and Safer Patient Care    While a surgeon’s life or limb is not at stake during an  operation (unlike an air disaster when a mistake made by an  airline pilot might result in the death of all those on board,  including the crew), the psychological effects of a major sur-  gical incident or error can be devastating to both individuals  and teams [6].    There are many personal human factors that can cause error,  including tiredness and fatigue, nutritional status, anger and  stress, multitasking and loss of our own situational aware-  ness. However, all too often as individuals we sometimes  imagine that these factors do not apply to us, and therefore  we might choose to ignore them (such as missing lunch,  working for many hours without taking a break) significantly  raising the risk of patient harm and potentially damaging our  own health and well-being.   These are known in aviation and other high-risk organisa-  tions (HROs) as significant factors that can cause human  error. As a result, strict guidelines have been put in place in  these HRO, with for example flight crews only being work-  ing a defined number of hours in any given month. Many  airlines have a policy in place to make sure that one pilot is  as refreshed as possible for the most dangerous aspects of  flying such as the landing. Intense concentration can only be  maintained for about 20-30 min. For example, one pilot will  take over the actual landing when the other has done the first-  stage descent. The effect of these personal factors in surgical  performance is less understood than in aviation though tired-  ness will affect decision making, as well as doing complex  tasks. Situational awareness will also be affected even if sur-  geons behave as if they are immune and operate for many  hours without taking a break. The ability for sleep depriva-  tion to degrade performance is dramatically under-estimated  by healthcare providers [7].   With reference to the Swiss cheese analogy, tiredness,  emotional factors and stressful surgery can all align together  to raise the risk of serious error. Table 42.2 shows some of  these high-risk situations. Good communication and team  working and the ability to question decisions with a phrase  such as ‘can I check that I’ve got this correct’ can be useful.  Other phrases like ‘I am not happy’ and ‘I am going to take  over’ can also be used in situations where an error might  happen.    dehydration are known to impair cognitive function and per-  formance [8]. Meals that contain protein, carbohydrates and  fats such as those derived from olive oil, fish and avocado as  well as certain nuts are considered to be best for optimal  nutrition. Simple sugars (such as chocolate bars) and pro-  cessed food do not readily support long-term concentration  and the endurance that is needed in the operating theatre [8].   The authors recommend taking a short break of 10-15 min  every 2—3 h when at work, especially if performing complex  tasks or surgery. Of course, the procedure can continue if  there is suitable expertise within the team, but each team  member should plan to take a regular break, which can be  staggered. Even a short time spent away from operating can  help provide a fresh outlook, improve morale, and enable a  toilet and food/water break. Recovery is aided through regu-  lar sleep, which is positively linked to healthy eating and  drinking. Certain nutritional supplements may also support  performance [9].   Emotional and psychological issues can affect performance.  While these emotions can often be hidden, a trigger or so-  called sentinel event that results in upset or even anger can  occur, during times of high mental workload or in those  stressful situations that we all will be familiar with. Many of  us will have witnessed others (or ourselves) having an emo-  tional outburst, including shouting at other team members.  During these events, error is much more likely to occur. In  these situations, visible anger usually results from additional  hidden factors that others do not see in the so-called anger  triangle (Fig. 42.3).   A simple thing to remember, HALT (Table 42.3), reminds  us of sometimes overlooked personal issues and to ensure we  stop to take a break. The importance of a short rest cannot be  emphasised enough if it is safe, especially when these HALT    Fig. 42.3 Anger triangle: many emotions may be hidden from others  until a sentinel event causes an outburst of anger. During this time, error  is much more likely    issues becomes apparent, and may prevent something seri-  ous from occurring.   Management strategies such as increasing our own emo-  tional awareness and learning how to deal with personal  stress may also be useful.    42.4. What About WHO and Other  Checklists and Team Working  Dynamics on Surgical Performance?    The WHO Surgical checklist has resulted in significant  decreases to post-operative mortality and morbidity on a  worldwide scale, yet errors persist and recur. While check-  lists, including WHO’s, cannot address all aspects of med-  ical and surgical practice, good team working with  effective briefing can help to optimise team performance.  There are many situations in surgery and other medical  specialities when mental or physical workloads increase  suddenly or dramatically (for example, during complex  microvascular reconstruction) and these can have an  adverse effect on performance. In such cases, team dynam-  ics and an understanding of each individual’s role within  the wider team are crucial. Airlines enforce a ‘sterile cock-  pit’ policy in which noise is kept to only essential conver-  sation below 10,000 ft (during high-risk procedures such  as landing and take-off) and only essential conversation  relating solely to procedure is permitted. The sterile flight  deck concept is being advocated for reducing error in  anaesthesia and surgery [10]. This should be discussed  with all team members at the pre-operative briefing so that  all know the need to stop non-essential communications at  certain times. Poor team working has had tragic conse-  quences on many occasions. In one well-known UK case  (Elaine Bromiley), the airway was lost following induction  of anaesthesia for a routine ENT procedure. The anaesthe-  tists made repeated attempts to secure an airway, and had  ‘tunnel vision’ about this rather than seeking assistance  from surgeons or others for an emergency needle  cricothyroidotomy.    Ancillary staff were well aware of the patient’s prolonged  hypoxic state but felt reluctant to assert themselves or state  the need for alternative intervention. No individual took a  leadership decision role and the team did not have designated  roles during a difficult airway situation. As a result, the  patient died when she could so easily have been saved. Lack  of leadership, poor communication, inability to challenge  hierarchy, and many other HF failings were to blame for this  tragedy.   Effective team working is also valuable in promoting a  sense of shared responsibility for patient safety. Team perfor-  mance is often improved when front line staff actively moni-  tor important performance criteria such as blood loss, regular  swab counts, and needle and instrument checks.   The WHO checklist and other team tools have helped  with theatre safety; however, never events still continue to  occur [4]. Much more is needed around safer team interac-  tions. The team brief, coupled to a debriefing after the day’s  operating, can enhance patient care, team working and feel-  ing valued by all.   Airline pilots discuss the ‘what if?’ scenario in pre-flight  briefings and know who will be doing what if something  doesn’t go well (Fig. 42.4). Some clinicians even go as far as  to ask team members ‘how could we kill this patient today?’  Table 42.4 summarises items that could be included in a  good briefing and debriefing. The nominated team leader can  summarise what has been discussed and repeat back as nec-  essary to confirm to everyone that there is shared understand-  ing. We also suggest monitoring each other for signs of loss  of situation awareness as well as looking for features of  tiredness and fatigue.   An open culture and respect by all team members are cru-  cial for better team working and enhancing patient safety.  Even the most inexperienced pilot will question decisions of  senior Captains without fear. While a hierarchal gradient  between trainees and their boss is needed, this should be suf-  ficiently flat to allow and encourage them to speak up when  something does not seem right. At all times, this needs to be  done in an environment where there is no fear of retribution  for speaking up about something that may appear trivial.   This concept is important in the team brief so that stu-  dents, trainees, and nurses all feel valued. We need to be aim-  ing for a ‘smooth and enjoyable flight’ in our workplaces,  even if the view isn’t as exciting as from the flight deck.    An important HF principle is recognising and understanding  how we relate and behave and how changes over time.  Surgeons can sometimes develop tunnel vision during long  procedures. This can be confounded by indicators that they  recognise confirm their behaviour, and thus may need to rely    42 Human Factors Recognition to Enhance Team Working and Safer Patient Care    Fig. 42.4 The three key elements that comprise situational awareness  (SA)    A well-prepared team knows their role, looks out for each other and  helps all to feel valued.  Briefing  Introductions, transparent culture, ‘anyone can speak if concerned’  Team working and leadership  Identify major parts of surgery and who is going to do what  Ask ‘What am I going to do if something goes wrong?’  Situation awareness—how can I intervene when something doesn’t  seem quite right  Decision-making skills  Debriefing  ¢ What went well today?  ¢ One thing I (we) could do more of?  ¢ One thing I (we) could do less of?  ¢ What will I (we) do differently next time?  ¢ Saying ‘Thank you’ to everyone    on other team members to identify a problem. Losing track  of time is one factor, which can lead to catastrophic conse-  quences as highlighted by the Elaine Bromiley incident men-  tioned earlier. An otherwise competent team lost their  situational awareness as critical minutes passed by during  failed intubation attempts. Her husband Martin (airline pilot)  knew about the same tunnel vision from a fatal plane crash,  where a prolonged attempt to troubleshoot a landing light  warning and a crew member’s failure to assertively commu-  nicate led to the plane running out of fuel.   A lack of situation awareness causes many diving acci-  dents. Recognising it for ourselves is important for develop-    ing surgical skill and where possible stopping what we are  doing when things do not seem quite right. A well-briefed  team will be able to recognise at a much earlier stage when  something is not quite right [11].   A simple diagram showing the three key components of  situational awareness is shown in Fig. 42.4.    Technology developments have led surgeons to perform  increasing minimally invasive procedures. Physicians also  do more invasive procedures such as interventional radiol-  ogy (IR), percutaneous coronary techniques and gastrointes-  tinal endoscopic surgery. The lessons learnt from surgery  and team briefs, WHO checklists and other HF training ini-  tiatives should be applied to other parts of the hospital.   Medicine is a challenging activity and patients are far  more complex than aircraft. Greater control is needed wher-  ever possible to minimise the risk of harm to others as a  result of human error. HF training can readily be taught  across medical practice leading to widespread improvements  in safety. It is clear that any HF training includes important  safety concepts, including better communication in teams, a  culture of open reporting without blame, regular safety brief-  ings and leadership skills. Aviation-based ‘Crew Resource  Management CRM’ training has improved reduction in  wrong site surgery. Hospitals need to recognise that they can  influence attitudes, culture and values towards patient safety.  HF training is simple, cost-effective and deliverable way of  getting all staff members involved.    HE and better team working, as well as commitment towards  continual performance improvement, are increasingly recog-  nised as essential aspects of patient safety. Despite this, seri-  ous medical errors have not been abolished. Many errors can  be prevented by recognising and using simple measures in  our clinical practice. An appreciation of those factors that  affect each of us as being potential contributors to error is a  great step towards improving safety for our patients.   We believe and advocate that HF training is essential for  medical staff as it is for airline employees. Since the intro-  duction of compulsory HF training in the early 1990s, there  has not been a single death on a UK-based airline due to  human error in more than 3 billion passenger journeys. An  individual would have to fly every day for 38,000 years  before experiencing a human error-related aviation catastro-  phe. 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Open Access This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.  org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropri-  ate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.   The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in  a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.   The exhilarating and exciting emotion of starting your own  practice can also be a daunting experience to a freshly passed  out maxillofacial surgeon. Student loans taken during the  course of one’s studies also play a significant role in deter-  mining one’s ability to take on any additional financial  burden.   As oral and Maxillofacial surgery is a bridge between  medicine and dentistry, there is a continual national debate  regarding the need to pursue a dual degree. The option to  pursue a condensed medical degree as part of the current syl-  labus is still not available in India. Thus, new residents  should always strive to do additional training [residency, fel-  lowship and diplomas] in their fields of interest to expand  their expertise prior to starting their own set-ups [1]. It is a  well-known fact that it is easier to gain knowledge and skills  during the starting of one’s career rather than later in life.  The goal is to aim high by keeping one’s feet grounded in the  soil of academics.   The fire of determination and passion should always be  kept alive in order to truly succeed and excel in our field. The  truly successful surgeon is the one who has thrived against  all the odds and taken advantage of every opportunity that  has come his or her way. This chapter aims to guide the  freshly passed out maxillofacial surgeon regarding further  avenues of learning and about the establishment and expan-  sion of one’s surgical practice.    of acquiring financial stability always appears alluring.  However, it is a well-known fact that enhanced surgical skills    S. G. Reddy (D4) - A. P. Acharya  GSR Institute of Cranio-maxillofacial & Facial Plastic Surgery,  Hyderabad, Telangana, India    © The Association of Oral and Maxillofacial Surgeons of India 2021    and strong academic knowledge cannot be traded for the  financial gains obtained by prematurely starting one’s surgi-  cal practice. Thus, it is always advisable to pursue additional  training in the form of a fellowship, residency or diploma in  one’s area of interests [2, 3]. This trend will help the surgeon  establish a niche practice where they specialize in a particu-  lar domain of oral and maxillofacial surgery, which eventu-  ally leads to improved surgical results and credibility for our  profession. This kind of surgical practice will also help to  create an edge over the plastic surgeon and the otolaryngolo-  gist and establish a distinguishable specialty offering an  unequivocal service to patients. Despite the prevailing cir-  cumstances governing one’s decision to enter practice imme-  diately or continue training, everyone will eventually  contribute to the OMFS field with their skills and  knowledge.   Laskin [4] made an organized attempt to tackle this prob-  lem by dividing the scope of oral and maxillofacial surgery  into three categories: areas of expertise, competence, and  familiarity. To be addressed as an oral and maxillofacial sur-  geon, one needs to include the areas of expertise and compe-  tence in their work profile.    e Areas of expertise include oral pathology/oral medicine,  dentoalveolar surgery, implantology, pre-prosthetic sur-  gery, and maxillofacial traumatology.   e Areas of competence involve orthognathic surgery, tem-  poromandibular joint surgery, and local reconstructive  surgery.   e Areas of familiarity are cleft lip and palate surgery,  regional reconstructive surgery, oncologic surgery, cra-  niofacial surgery, and cosmetic surgery.    The first step in learning a skill is to know how a skill is  learned. Educationists have constructed many models  attempting to outline the learning process. The most widely  accepted was first documented by Noel Bunch and was sub-  sequently re-worked by Abraham Maslow (Figs. 43.1 and    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1-15-1346-6_43    43.2). In the beginning, a student is in the ‘unconsciously  incompetent’ phase. An undergraduate dental student in their  third year would have no idea about administering local  anaesthesia. After working on the skill for some time, they  move on to the ‘consciously incompetent’ phase. Here, they  have attempted different ways of anaesthetizing teeth and are  now keenly aware of the various ways to give local anaesthe-  sia along with their shortcomings in certain regional nerve  blocks.   Most of our trainees will arrive somewhere between  these two steps of knowing what they can and cannot per-  form. Educators must help them overcome their limitations.  Once they are aware of their shortcomings, they can actively    begin to correct them. With practice and appropriate teach-  ing, they move to the third level of being ‘consciously com-  petent’. Here, the trainee can perform every step of local  anaesthesia along with variations of different techniques.  However, the steps require focus and assiduousness. Now,  he or she would be considered as a competent surgeon who  can practice independently although lacking in instinctive-  ness. As learning advances, with years of handwork and  practice, they will reach to the concluding stage, ‘uncon-  sciously competent’. Now the local anaesthesia can be  given while listening to music or talking to patients or col-  leagues [5].   The obstacle to a meticulous ‘ability preparation’ is that  most of our instructors perform numerous components at  an unknown and advanced skilled dimension, while the stu-  dents are frequently unmindful of numerous components of  what they have to learn. The individuals who have over-  looked the subtleties of an expertise are entrusted with  showing people who don’t know about what abilities they  are unequipped for performing. The initial step for an ace  instructor is to perceive that the educator and understudy  live at inverse finishes of the authority. Perception, readi-  ness, practice and tolerance are the key components of  learning in any skill [6].    Such a great amount of training with an expertise that it has moved  toward becoming "second nature" and can be performed effectively.  The expertise can be performed while executing another    Comprehends or realizes how to accomplish something.  Showing the expertise or information requires fixation.  May be separated into steps, and there is overwhelming  conscious involvement in executing the new skill   Does not perceive the shortfall or value of the ability.  Perceive their own ineptitude and estimation of the new  expertise   Recognizes the shortage, just as the estimation of another  ability intending to the shortfall.   Creation of slip-ups can be basic to the learning procedure  at this stage    David Kolb is renowned in educational circles for his  Learning Style Inventory. In Kolb’s speculation, the drive for  the headway of new thoughts is given by new experiences.  “Learning is the technique whereby data is made through the  difference in comprehension” [7]. Kolb’s experiential learn-  ing style theory is conventionally addressed by a four-stage  learning cycle in which the understudy contacts all of the  bases (Fig. 43.3). Along these lines, everyone responds to  and needs the improvement of a wide scope of learning  styles.   They are keen individuals, will in general be inventive  and enthusiastic, and will be solid in expressions of the  human experience. Individuals with the veering style like to  work in gatherings, to tune in with a receptive outlook and to  get individual criticism.   (doing / having  experience)  Active Reflective  Experimentation Observation  (planning / trying out (reviewing / reflecting  what you have learned) on the experience)   This learning style is essential for viability in data and  science vocations. In formal learning circumstances, indi-  viduals with this style incline toward readings, addresses,  investigating diagnostic models, and need room to thor-  oughly consider things.    Individuals with this combining learning style can tackle  issues and will utilize their figuring out ability to discover  answers for reasonable issues. They lean toward specialized  assignments and are less worried about individuals and rela-  tional angles.   Individuals with a combining learning style are more  pulled into specialized errands and issues than social or rela-  tional issues. A meeting learning style empowers expert and  innovation capacities. Individuals with a meeting style like  to try different things with new thoughts, to recreate, and to  work with handy applications.   Individuals with an obliging learning style will in general  depend on others for data than complete their own examina-  tion. This learning style is common inside the all-inclusive  community. To become familiar with specific, careful abili-  ties, an understudy needs to go intensively through every one  of the styles of learning. First, we have to observe, think and  feel pursued by experimentation on models to learn the apti-  tude to do medical procedure on humans.    Transformative learning is the procedure by which we digest  and decipher data based on our own encounters to date, to  deal with ace Surgical aptitudes. This can be seen in a case of  a boss helping a careful student with his or her first case. One  of the key issues is for the chief to be accessible if for no  other explanation other than to counsel, whenever required,  and guarantee that things go easily. Grown-up students need  to realize that they have the director’s certainty and support    and that they will be permitted to extend their range of abili-  ties to attempt to take care of any issues they may experi-  ence, before the chief strides in.   The following enquiries of destinations and points can  give understanding into the learner’s self-appraisal capacity  or trainee’s self-assessment:    e The student endeavours to pursue the pre-operative plan  and, if there is a deviation, guarantees to take assent from  the supervisor.   e The supervisor controls through the central specialized  advances and focuses on technical steps and gives asser-  tion for leading following the next stage, simply after  fruitful fulfilment of past advances.   e The teacher gives prompt input on what is being pro-  gressed admirably and what should be possible in an  unexpected way.   e The chief considers enabling the student to accomplish  more on the off chance that they are advancing admirably  and exhorts them in like manner.    Post-operative questioning  This can begin to happen as the student is concluding the  case; however, a few learners may discover this diverting,  which may hamper their execution.    e Ask the student how they think they went, invigorate  reflection and show general tenets; help them survey their  execution; investigate ways they can set a few objectives  to help address insufficiencies   e Provide explicit instances of how the student could have  performed better. An administrator may figure the learner    Oral and maxillofacial surgery gives a wide range of alterna-  tives from a conventional private minor oral surgery practice  to specialist maxillofacial surgery in trauma, temporoman-  dibular surgeries, orthognathic surgeries, implantology,  oncology, aesthetic surgery and cleft and craniofacial sur-  gery [9]. The following are the alternatives, which can be  taken by a newly passed oral and maxillofacial surgeon:    ¢ Associateship—tThe possibility of associateship with an  officially settled practice is by all accounts extremely  appealing. By joining a specialist set-up, one stays away  from the numerous costs and unpleasant circumstances  involved in setting up one’s own practice. However, one  should make sure to join the right specialist practice.  There is a lot of contrast between a specialist that genu-  inely needs a partner and a specialist that may need a part-  ner for increasingly narrow-minded reasons. The practice  may not have enough volume to support two specialists  and the senior associate may. In this situation, the new  specialist may be in charge of creating the new referrals.  This can be a troublesome circumstance. In addition, one  may anticipate that as the new associate one should take  an excessive measure of call, see all patients with insur-  ance formalities and not take an interest in the ‘great  cases’. Additionally, the desires of the senior associate  might be farfetched and a lot of additional fault may be  put on the new junior associate. Before getting engaged  with any of the associateship, the term and conditions  ought to be clear in the pre-legally binding stage [10].   ¢ Scholastics and Research—Teaching is one of the alter-  natives for a specialist who has the enthusiasm to educate  the new batch of upcoming surgeons. It is one of the best  ways to remain connected with your field. There are many  institutes looking for youthful surgeons with a keen inter-  est in academics, research and administrations [11].   ¢ Organization—Being a manager includes leading, man-  aging, overseeing and supporting health care departments  or associations to accomplish their pre-set goals. With the  opening of a several corporate hospitals, administrators  with a medical background are most desirable for such  roles. The size, intricacy and mission of various health-  care organizations (hospital systems, academic medical  centres, practice groups, insurance companies) require  assistance from experienced specialists with fluctuating  roles [12].    De novo Practice—Opening one’s own OMFS office  from the ground up is an extremely tough task that is not  for the weak hearted. It has been rightly said the war field  ought not be entered without a weapon and thus one need  to be confident in their surgical skills and also have a  basic understanding of the administration involved with  running one’s own practice [10].    Surgical Skills: Never accept surgery as an easygoing  endeavour and always keep the patient’s prosperity over  any of your own advantages. It is important to develop  surgical skills early on in one’s career as it is these skills  that will carry you forward throughout life. However, one  should also make an effort to get the right opportunity  Site or place of your practice: Selection of the place  where you will set up your centre is the first and most  basic decision that one comes across. Choosing a location  that has a geographic advantage [as in easily accessible  via adequate public and private transport] and has an ade-  quate population to support your practice is essential.  Demand and supply also needs be considered when  choosing your location. Too many competing specialists  in the vicinity will definitely make attracting patients dif-  ficult. However, it must be said that the eventual fate of a  practice depends on the surgical skills and services offered  by the surgeon in charge. Lastly, the spot ought to be close  to the living arrangement of the surgeon in case of a medi-  cal emergency [13].    e Accounts or Finances: It is prudent to begin a project of    such magnitude with your financial capacity in mind.  Very few specialists manage to acquire stipends during  their residency programs and hence are not well  acquainted with handling funds. One should avoid large  and unnecessary expenses in the beginning. However, this  does not mean that one should skip on the basic require-  ments for starting a well-equipped practice. Expansion,  modernizing and incorporation of advanced technology  into the practice must be kept as a long-term step wise  plan. The computations of property expenses [rent/lease/  loan], staff salaries, equipment costs, sterilization and  biomedical waste management ought to be dependably  considered in evaluating the finances [14].   Framework: The rooms required in an OMFS workspace  are as follows: reception room, business zone, financial  zone, exams rooms, operatories, x-ray zones, research  centre space, staff lounge, specialist’s private office, rest-  rooms, medicinal gas space, mechanical space, steriliza-  tion space, recovery space and storage space [10].    Marketing strategy: Health care associations actualize busi-  ness techniques through projects and administrations, and  achievement relies upon program structure and execution.  Beginning a business adventure without an arrangement is  out and out welcoming a fiasco and human services is no  exemption for this standard. Since we are specialist co-ops,  we ought to dependably remember that this field is certifi-  ably not a “high pay” creating field except if we are manag-  ing corporate divisions. That is the reason why practical  objectives ought to be set to keep ourselves as well as other  people away from the rat race of cash. This positively doesn’t  imply that you ought not dream about a sensible way of life.    Sole Proprietor—This is for the specialist who already  has a foundation of maxillofacial surgical or other medi-  cal service organizations running in the family. The  choice appears to be practical for the surgeon who has  full control of his financial assets and is as of now expe-  rienced in the field [15].   Organization or associateship—lf you have fellow med-  icos who are of the same or diverse fields and are pre-  pared to create a combined practice with you, then it is  the most reasonable choice. Always scrutinize your col-  leagues before entering into such arrangements. The  success of this arrangement relies upon mutual trust for  each other. It is also necessary to discuss all the terms  and conditions [expenses and division of profits] before  entering such an arrangement.    settled specialist and eventually move toward becoming a  partner in the not-so-distant future [15].    Corporate segment. Joining corporate hospitals or chains  is also an alternative. The hustles of marketing, equipment,  and location can be obliterated. However, corporate hospi-  tals today are keen on hiring well-settled specialists as  patients are hesitant being treated by novice surgeons [15].  Trust or NGOs—These organizations are created to help  unaffording individuals for treatment. One cannot expect  great monetary benefits from a trust or NGO. However,  there is a feeling of fulfilment of helping other people.  There are a few associations in and outside India, which  raise funds for such organizations. A point worth noting  is that there are numerous specialists who are working  free of charge under such associations while simultane-  ously obtaining their standard pay elsewhere [15].   Due to the contingent nature of the decision of essential  structure be it sole owner or in affiliation, Strategic arranging  is required. It is a definite methodical report demonstrating  the manner in which it intends to advance from its present  circumstance to the ideal future situation [16].   The SP procedure is isolated into progressive stages. The  writing gives diverse names to unmistakable stages yet we  are adopting established strategy, distinguishing five values  simultaneously. The Mission, Vision and Values ought to be  institutionalized amid the underlying stages.   e This mission characterizes the general motivation behind  the association, the objective customers, the administra-  tions offered, its distinctive highlights, the geological ter-  ritory in which the centre works, and occasionally the  manner in which it works (quality, morals, productivity,  and so forth.).   e This examination generates data on those difficult to  change external variables that can affect the association.  This involves patients and contenders.   e Patients: The place that you will eventually set up should  have a geographic advantage with the right patient demo-  graphic. All too often, a specialist will begin their facility  in a distant, underdeveloped and immature zone due to  the dread of rivalry. It is a well-known fact that a special-  ist practice survives on referrals and not only on walk-in  patients.   ¢ Contenders: Good work and identity are significant in  keeping an edge over your rivals. Endeavour to build up  your individual character, as far as work and morals are  concerned, should be made.   ¢ This investigation generates data on everything pertinent  that has/can and is happening inside the set-up. This  investigation centres around three distinct angles:   — Resources: It incorporates individuals, monetary  spending plans, consumable and non-consumable sup-  plies and their level of obsolescence.   — Analysis of clinical and research work, action and  spending plan ought to dependably be kept aside [16].   e When the outside and inside examinations have been fin-  ished and coordinated, the vital arrangement directing  gathering will have an abundance of thoughts regarding  conceivable vital activities that could be tended to in the  arrangement. Then, the issues distinguished in the exami-  nation are characterized into four classifications to com-  prehend what to do and in what request. This is the SWOT  investigation, an abbreviation framed from qualities (S),  shortcomings (W), openings (O) and dangers (T), which  orders the consequences of the examination.   e Every one of the outcomes, notwithstanding grouping  them with SWOT criteria, can be weighted as far as sig-  nificance or relative power (high, medium, and low; +, ++  or +++, and so on.). It permits the arranging group to  build up a positioning, with the most vital components  positioned in the principal position, situated to key priori-  ties [17, 18].    TOWS Matrix Analysis  The TOWS Matrix is aimed at developing strategic options  from an external-internal analysis. TOWS idea is firmly  identified with SWOT investigation. Whereas SWOT  Analysis starts with an internal analysis, the TOWS Matrix  starts the other way around, with an external environment  analysis; the threats and opportunities are examined first. As  indicated by H. Weihrich (1982) [19], Dangers, Opportunities,  Weaknesses, Strengths (of the association) ought to be exam-  ined in a specific order, as a critical thinking succession dur-  ing the time spent on the procedure plan. To streamline, let’s  use TOWS examination in beginning an oral and maxillofa-  cial medical procedure set-up:   ¢ The individual variables of the specialist like family foun-  dation, past experience, unique intrigue, administrative  and specialized abilities, self-assurance, inventiveness,  creativity and eagerness to go for broke    Individual shortcomings (inside negative factors or chal-  lenge) like deficient abilities, terrible work propensities or  attributes like poor relational abilities, poor systems admin-  istration, ineffectual authority characteristics, absence of  specialized mastery, absence of IT information, absence of  comprehension of statistical surveying, absence of promot-  ing skill and so on because of which wrong choices are gen-  erally taken.   S-O—How can the organization employ the expertise of  its own professionals to respond to the needs of centres? By  partnering up, the organization can convince the institutions  that there is enough capacity, knowledge and experience to  train young people to independent professionals at all levels  of surgery.    ¢ SO circumstance—maxi-maxi system. This circumstance  compares to the maxi-maxi methodology whereby it is  conceivable to have solid extension and broadened  advancement. In such cases, if the cost is utilized as to  prepare individuals and keep them on minimal effort at  first to give complete consideration by the prime special-  ist will prompt bringing down of beginning costs. Along  these lines, more income is produced amid starting days  just to have the capacity to rise as market pioneer.    S-T—How can the organization use its skilled staff to  compete with cheaper workers employed by competitors? A  smart approach for the organization would be to communi-  cate to the outside world that their staff has accredited diplo-  mas and that it’s important for health care centres to comply  with legal requirements and safety standards.    ¢ ST circumstance—maxi-little system. The wellspring of  troubles in development and improvement are ominous  outer conditions (predominance of dangers) like a lot of  swarming of good oral specialists in the zone, or patients  paying limit is low, and so on. The procedure should uti-  lize vast interior qualities in endeavour to defeat dangers  from environment. The technique of reaching and catch-  ing patient ought to be connected through free camps,  minimal effort medications contrasted with encompass-  ing zones and catching exchange out specialists. On the  off chance that the ability of the prime specialist is awe-  some, settle on troublesome cases left by different spe-  cialists with the dread of disappointment. In addition  more up-to-date methods and medical procedures ought  to be aced by the specialist in such cases.    W-O—How can partnerships with other centres help the  organization to improve itself and put more effort into patient  acquisition? By presenting itself as an accredited apprentice-  ship provider, the organization will put itself on the market  again and its shows that adapt to changing times and wants to  offer different kinds of treatments.    e This circumstance has more vulnerabilities—shortcom-  ings, yet its condition gives more open doors like less  number of oral specialists in the town and so forth. The  procedure ought to incorporate the utilization of these  chances while decreasing or amending shortcomings  inside. Executing the arrangement step by step is required  in such cases. The emphasis ought to be on improving the  patient experience by great work by prime specialist, less  staff and nearly not all that extravagant set-up amid  introductory stage. Along these lines, cost cutting should  be possible successfully without settling on the treatment  plan. As the patient information and OPD increments, fur-  ther advances can be taken for extension.    W-T—How can the organization better position itself in  the market and thus reduce the threat posed by competitors?  By presenting itself as an accredited apprenticeship provider,  the organization can claim that they are a serious competitor  and can possibly offer healthcare services by apprentices at  reduced rates, with the work still being done by the prime  specialists.    ¢ WT circumstance—smaller than usual little methodol-  ogy. This circumstance is without any advancement  openings. It works in antagonistic situations, and its  potential for change is little. It doesn’t have huge quali-  ties, which could withstand dangers. Scaled-down  smaller-than-expected technique comes down to a nega-  tive rendition of the shut down or in idealistic circum-  stance—to take a stab at survival keeping in mind the   e Equipped with this arrangement of recommendations, the  vital arrangement controlling gathering starts a proce-  dure, which orders them into characterized territories of  activity. These zones of activity are additionally at the  same time distinguished and named relying upon the kind   e Now, it is prudent to adjust the procedure definition cre-  ated, to check whether in reality a methodology exists by  asking the accompanying inquiries:   — Are the key decisions that have been made substantial  in the long haul?    On the off chance that there are negative answers, the  detailing ought to be looked into to check whether, rather  than shaping a key arrangement, an arrangement has been  made with a progressively restricted scope [16].   The point of operational arranging is to make the arrange-  ment totally explicit, viable and unmistakable. The Operation  destinations unite the accompanying attributes:    e They must have a fixed length, in every case under | year.  Middle-of-the road objectives can be built up to be com-  pleted in various stages after some time.   e They ought to be evaluated. To follow their level of con-  summation, pointers that measure this are oftentimes  required.   e They ought to challenge and keep the association in a  condition of alarm so as to accomplish them.   ¢ Each objective must have an assigned individual in con-  trol, who truly has the ability to change the execution of  the unit or subunit.   ¢ Each Objective must have a cost doled out to its usage,  with the end goal that the all-out expense of all the goals  is equivalent to the absolute expense of the key  arrangement.    e Each Objective must have the financing and different  assets (staff time, gear and so forth.) important to accom-  plish the goals.    When all the OOs are detailed, the execution has to be  incorporated with that of the others inside a course of events  of activities that incorporates every one of them and gives an  outline of the connections, timing and succession of errands,  just as the joined endeavours that the HO needs to perform at  each stage.   Auspicious evaluation of results ought to be done, which is  dependent on development of number of patients, nature of  administrations, nature of medical procedure, income age  and work fulfilment. This should be possible by figuring the  development charge. Arbitrary overviews on the web or dis-  content ought to be finished with the assistance of patients  to keep up the pace of association and know the dimension  of fulfilment of the patient with the health care providers,  i.e. the head and the staffs. Likewise, number of patient  waiting ought to dependably increase steadily for a feasible  growth [16].    ¢ Jtis a must that both the specialist and the staff also show  consideration for the patient’s needs and have a humble  attitude. This will go a great length in gaining the good  will of the patient and word-of-mouth referrals.   ¢ Utilizing online marketing tools through advertisement  and social networking are slowly becoming a must for  every new practice.   e Showcasing your work in study clubs, get-togethers and  association conferences will also make fellow medicos  aware about your abilities.   ¢ You can publish in the neighbourhood newsletters through  knowledgeable articles with respect to your field.   ¢ Conducting free camps for check-ups with the neighbour-  hood non-profit associations can also help showcase your  aptitudes.   The staff should be skilled in their work and maintain a hum-  ble and empathetic attitude. Always hire and maintain the  correct staff    ¢ Make clear what is expected of them through a detailed  manual   ¢ Train them to be focused in their specific roles and reward  them for their endeavours   Communication or Correspondence is most imperative for  achieving the great name as an expert. Thinking from the  patients’ point of view and attempting to clarify in straight-  forward however non-phobic words about the method will  help in building up the trust of patient for the specialist.  This will likewise spare the legitimate ramifications if there  should be an occurrence of adversity, which can emerge by  not disclosing the intricacies appropriately to the patients.  The way toward relieving a patient requires an all-  encompassing methodology, which includes contempla-  tions post treating a malady. It warrants a few aptitudes in a  specialist along with the specialized ability. Studies have  showed great correspondence ability in a_ specialist  improves patient’s consistence and general fulfilment.  There are fundamental standards of rehearsing great corre-  spondence. Persistent tuning in, compassion, and focusing  on the para verbal and non-verbal parts of the correspon-  dence are the essential steps that are often disregarded.  Appropriate data about the nature, course and forecast of  the infection are essential. Additionally, patients and order-  lies ought to be clarified about the need and yield of costly  examinations and dangers/benefits engaged with obtrusive  strategies. One ought to be mindful while overseeing trou-  blesome experiences and breaking awful news. Formal  preparation of the specialists in improving relational abili-  ties is vital and has demonstrated to improve outcomes.  Furthermore, it is additionally helpful in overseeing diffi-  cult clinical experiences. This way diminishes the disap-  pointment of both the specialist and the patient or chaperon  in circumstances of enthusiastic upheavals. It has also  appeared to diminish work pressure and increase work ful-  fillment [22].   Record keeping is vital to a successful practice especially  in view of the legal implications that come along with a  failure to maintain the same. One should maintain both a  hard copy and a virtual copy of their records as backups  are most essential. Informed consent forms should clearly  record possible complications in a language understood  by the patient. Photographic records at the preop, intraop,  and postop phases need to be maintained and become  especially important when a patient has unrealistic expec-  tations. It is also important to maintain well-documented  out-patient records and operative notes. Never forget the  seventh principle of the Caldicott report, an NHS report  on patient information, which says ‘the duty to share    information can be as important as the duty to protect  patient confidentiality’ [23].   If at any point of time you come to realize that your practice  is unable to achieve patient needs or financial goals, it is time  to reconsider your strategy [16].   Nothing is permanent in life and in one’s career. You can run  your profession for a particular timeframe to be trailed by  slow decrease in the training with age. Wellbeing and pros-  perity play a vital depiction to build the life span of the train-  ing (Fig. 43.4a). Till 45 years, there is a tendency to achieve  followed by continuous decrease in the field. The thought is  to augment the achievement with slow decrease. A specialist  can viably work till the age 55-60, which can be expanded  till 65-70 with great wellbeing and consistent learning. It is  the duty of old specialists to offer approach to novel special-  ists for the improvement of field. Supportable model can be  made to prepare novice specialists followed by naming them  as partners.   Time is the most essential commodity that we have in our  lives. Digitalization of many facets of hospital management  has helped save time. This time can be re-invested in various  other aspects of your clinical practice like discussion regard-  ing treatment planning and discussion of various cases.  Make sure you plan your day daily and weekly so that you  are aware of the time that you have and be able to invest it  wisely [24].   One must learn how to handle finances appropriately;  unnecessary and exorbitant spending at the earlier stages is  not a wise idea and can lead to a sudden financial crisis,  which can even lead to the premature end of one’s career.  As mentioned before, expansion and modernization of the  practice should follow a well-thought-out long-term incre-  mental approach. Similarly, it is wise to slowly create an  alternate source of income to help tide over any financial  crises that one may face throughout the course of their  career [25].    Oral and maxillofacial surgery is gaining popularity as a  field and general awareness is increasing in India. It is the  responsibility of new surgeons to contribute their best to  the field in order to get the maximum out of their careers    MM) TIME FOR PRIMARY INCOME GENERATION  {)) TIME FOR SECONDARY INCOME GENERATION    c  ) INCOME FROM PROFESSION  {) INCOME FROM INVESTMENT  60-75  <  °  oO  2 45-60  s  a  x)  o  z  35-45  25-35    Fig. 43.4 (a) Professional life cycle of oral and maxillofacial surgeon.  (b) Time management in the life of a maxillofacial surgeon. (c) Finances  management in the life of a maxillofacial surgeon    and life. As is said ‘Do good and it will come back in unex-  pected ways to you’. Never lose your principles and ethics  in this competitive world as it will only tarnish your reputa-  tion. Everyone has a specific purpose in this world. The aim  is to find that purpose and work upon it with the help of the  skills and knowledge you have gathered. These were my  rules for success that I stumbled up on while achieving my  goals. The newer generation is getting smarter and sharper  and will surely contribute to a new set of rules and redefine  success.    1. Samman N. The modern specialty of oral and maxillofacial surgery.  2009;14(6). Dental Bulletin, The Hong Kong Times.   2. Kumar S. Training pathways in oral and maxillofacial sur-  gery across the globe—a mini review. J Maxillofac Oral Surg.  2017;16(3):269-76.   3. Clark PK, Markiewicz MR, Bell RB, Dierks EJ. Trends and atti-  tudes regarding head and neck oncologic surgery: a survey of  United States oral and maxillofacial surgery programs. J Oral  Maxillofac Surg. 2012;70:717-29.   4. Laskin DM. The past, present, and future of oral and maxillofacial  surgery. J Oral Maxillofac Surg. 2008;66:1037—40.   6. Sadideen H, et al. Surgical experts: born or made? Int J Surg.  2013;11:773-8.   7. Kolb DA. Experiential learning: experience as the source of learn-  ing and development, vol. 1. Englewood Cliffs, NJ: Prentice-Hall;  1984.   8. Knowles MS. The modern practice of adult education: Andragogy  versus pedagogy (Revised edition). Prentice Hall/Cambridge:  Englewood Cliffs; 1988.   9. Haider SM, et al. Oral & maxillofacial surgery; A historical review  of the development of the surgical discipline. Int J Surg. 2018.   10. Niamtu J. Beginning a new oral and maxillofacial surgery practice.  11. Walker TW, et al. Educational paper: research in oral and maxil-  lofacial surgery. Br J Oral Maxillofac Surg. 2010;48(8):629-32.   12. Ghosh R, et al. Management and leadership skills for doctors. BMJ.   13. McDonald S, et al. Where to put an OMS practice, A supplement to  the AAOMS. Today Newsletter. March/April 2007.   14. Pollock SL, et al. Financial arrangements in an oral and maxillofa-  cial surgery practice, Part II, A supplement to the AAOMS. Today  Newsletter. March/April 2009.   15. Miron-Shatz T, et al. Promoting business and entrepreneur-  ial awareness in health care professionals: lessons from venture  capital panels at Medicine 2.0 Conferences. J Med Internet Res.  2014;16(8):e184.    Rodriguez Perera Fde P, et al. Strategic planning in healthcare orga-  nizations. Rev Esp Cardiol (Engl Ed). 2012;65(8):749-54. Epub  2012 Jun 13.   Weihrich H. The TOWS Matrix: A tool for situational analy-  sis, Long range planning. 1982;15(2):54—-66. https://doi.org/  10.1016/0024-6301(82)90120-0.   Bhangale V. Marketing of healthcare services in India: a study on  factors influencing patients’ decision making on choice of a hospi-  tal. J Manag Market Healthcare. 2011;4(4).    Mamoon Z, et al. Hiring the right people for your organization.  Glob J Manag Bus Res Admin Manag. 2013;13(8).   Ranjan P, et al. How can doctors improve their communication  skills? J Clin Diagn Res. 2015;9(3):JEO1-4.   Mathioudakis A, et al. How to keep good clinical records. Breathe  (Sheff). 2016;12(4):369-73.   Christie S, et al. How to improve your time management skills.  BMJ. 2012;344    Open Access This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.  org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropri-  ate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.    The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in    a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.   In the modern world, human activity is governed by a set of  rules and regulations collectively referred to as law. All pro-  fessions must follow legal requirements and this is especially  important while practising health care, including maxillofa-  cial surgery. Doctors must be aware of their duties, rights and  scope of practice within the framework of the laws governing  their respective countries or states. This is especially impor-  tant for maxillofacial surgeons, who straddle the line between  medicine and dentistry. This chapter aims to outline the vari-  ous legal issues that pertain to the maxillofacial surgeon. The  laws referenced are mostly India centric, but the general prin-  ciples are not very different from international laws.    44.2. What Are the Legal Issues That Must  Concern the Maxillofacial Surgeon?    Since the role of a maxillofacial surgeon acts as a link  between the medical and dental professions, the scope of  practice has always been controversial. Maxillofacial sur-  geons have moved from beyond the oral cavity to the head  and neck region, and even to distant body parts for proce-  dures such as flap harvesting. All maxillofacial surgeons  must be aware of what procedures they are allowed to prac-  tice under the law and what they must avoid.   During any procedure, legal documentation is of utmost  importance. These include informed consent and filing  medico-legal reports. Informed consent is a legal necessity to  prove that a patient is willing to undergo a procedure.    G. Paul   Kerala University of Health Sciences, Thrissur, Kerala, India    M. Rai  Department of OMFS, A. J. Institute of Dental Sciences,  Mangalore, Karnataka, India    © The Association of Oral and Maxillofacial Surgeons of India 2021    Medico-legal reports must be filed when one treats a case  that could potentially become a legal issue. Maxillofacial  surgeons may be called upon to testify as expert witnesses in  legal cases such as assault and road traffic accidents. They  should therefore be aware of procedures required to docu-  ment evidence in these cases.   Finally, all medical professionals are vulnerable to mal-  practice suits. The surgeon must be aware of what actions  could put them at risks for facing such suits and what proce-  dure must be followed if one ever faces a malpractice  litigation.    44.3 Scope of Practice of Maxillofacial  Surgery as per the Indian Law    Oral and Maxillofacial Surgery has a unique place in the  health care systems around the world. It is a stand-alone spe-  ciality in modern medicine that has its provenance in den-  tistry. However, when one realizes that modern medical  systems are barely more than a century old, it is not long ago  that the treatments of dental and oral diseases were a part of  an integral system that encompassed holistic health care.   Dentistry as a separate autonomous specialty is an accident  and an aberration in the history of modern medicine. In fact,  the first dentists were medical doctors or surgeons like Pierre  Fauchard in France who had a special interest in treating den-  tal and oral conditions [1] and John Hunter [2] in England.   In the late nineteenth and early part of the twentieth cen-  turies, dental schools and curriculums were established as  courses separate from medical courses and the bifurcation  became an established practice in different countries in  almost all continents [3, 4].   It is through this prism that we need to view the speciality  of OMFS and its future as a complex and distinct part of  health care. In fact, training to become a maxillofacial    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1-15-1346-6_44    surgeon through the route of dental surgery is unique when  compared to other distinct regional specialties, which emerge  as a post-medical qualification, e.g. ophthalmology, otolar-  yngology, or gastroenterology.   Realizing the need for adequate training in surgery, sub-  stantial additions were made to the dental and oral and max-  illofacial surgery curricula by including several basic medical  sciences and clinical medical subjects in the undergraduate  and post-graduate level, to help meet the medical training  requirements of a surgeon.   The impetus for the evolution of OMFS was provided by  the two World Wars of the twentieth century and other armed  conflicts, where dental and oral surgeons were found to be  invaluable in the treatment of facial bone fractures. Thus,  Oral and Maxillofacial Surgery was born as a speciality of  dentistry and went on to encompass a wide range of surgical  work, including pathologies of the mouth and jaws, TMJ sur-  geries, surgical corrections of dento-facial deformities and  cosmetic surgery of the face.   In many countries, including those in Europe, this resulted  in the concept of dual degrees (medical as well as dental  degrees) to better address surgery in a complicated region of  the body where one needed a clear understanding of surgical  principles as well as sound dental concepts. Duality is often  mistaken for an additional medical degree. In fact, duality  includes the need for a dental degree for those with a medical  background. In countries like USA, India and several Asian  countries, oral and maxillofacial surgery continues to be a sur-  gical speciality of dentistry, although some surgeons chose to  do medicine as additional qualification to further their interests  and knowledge [5]. Similarly, dentistry was offered as an addi-  tional degree for those with medical qualifications only.  Dentistry was however an essential pre-qualification to become  a maxillofacial surgeon. It must be remembered that 90% of the  world population is still serviced by OMFS with a single dental  qualification re-enforced by rigorous surgical training as part of  their post-graduate curriculum. This includes the USA, Canada,  Latin America and the Caribbean, Africa, China, Russia,  Central Asia, South Asia, Middle East Asia, South West Asia,  Japan, and Far East Asia [6-12]. Starting in the 1970s, several  countries also offered integrated 6-7 year residencies leading  to OMFS that provide an additional Medical or Dental degree  depending on their original background.   The curriculum for Oral and Maxillofacial Surgery in  India and several other countries has been suitably modified  for patient safety and competence. In India, the speciality of  OMFS is regulated by the Dentist Act of 1948 as more than  90% of OMFS are dental-qualified surgical specialists [13].  OMEFS has been included as a recognized speciality with dis-  tinct privileges in the medical health care system and has  been included in significant legislations at the national and  state levels, including the Clinical Establishment Act of  2012.    Oral and Maxillofacial Surgery is a recognized department  in most multi-specialty hospitals and they are given privi-  leges such as admissions and autonomous departments  within the surgical or dental services.   The Dentist Act has defined Oral and Maxillofacial  Surgery as a surgical branch of dentistry dealing with dis-  eases affecting the mouth, jaws, and face. The updated cur-  riculum of OMFS is a focused training in surgical  management of diseases, injuries and deformities of the face  and gnathic system. Training includes interdisciplinary rota-  tion with allied surgical specialities and standard compe-  tence in dealing with complex surgical situations in the  mouth, jaws and face.   In an increasingly competitive surgical arena, different  surgical specialities compete for ownership of procedures  based on their diverse backgrounds. It is therefore expected  that OMFS, as an emerging surgical specialty, is sometimes  in conflict with other specialities.   The legal competence to perform procedures is dictated  by the qualification and training received as part of the cur-  riculum set up by the respective statutory bodies through due  process of law.   The legal remit and privileges of OMFS in India are based  on the training received as part of the curriculum of the mas-  ter’s degree in Oral and Maxillofacial Surgery as outlined by  the Dental Council of India in its regulation issued from time  to time. The current syllabus, curriculum and training equip  the specialist to deal with a wide range of surgical proce-  dures in the face, jaws, oral cavity and teeth. This includes  comprehensive management of defects or deformities of  dento-facial region caused by congenital anomalies, injuries  or surgical ablation. However increased competence, like in  any other surgical speciality, is achieved through experience  and continuous training in the form of fellowships and struc-  tured courses.   Oral and Maxillofacial Surgery falls into a grey area,  overlapped by several other surgical specialities. However,  competence is defined by the scope offered by legally  approved training within the framework set out by the statu-  tory bodies in the respective countries. In India, OMFS is an  advanced surgical specialty of dentistry and its remit is regu-  lated by the Dental Council of India.    44.4 Legal Requirements to Be Followed  When Dealing With a Patient  44.4.1 Informed Consent    Consent to medical treatment as an ethical and moral prin-  ciple is probably as old as medical science. It is inconceivable    that a medical practitioner at any point in history would have  treated or operated on a patient without his or her permis-  sion. However, consent to treat as a legally binding entity is  of recent origin. Today, it is validated by multiple principles  drawn from social and behavioural sciences, moral philoso-  phy, human rights, ethics and laws of a particular country.  One of the main guiding principles of Informed consent  involves the rights of patients to make clear assertions of  what can or cannot be done to their bodies based on unbiased  and full disclosure of the benefits and risks that will ensue  from treatment. While most diagnostic treatment procedures  are today performed only with a clear informed consent,  there are some which attract particular attention in the matter  of informed consent, e.g., HIV testing and high-dose radia-  tion in vulnerable patients.   Farlex’s free online dictionary [14] has a simple definition of  Informed Consent. It is “Consent by a patient to a surgical or  medical procedure or participation in a clinical study after  achieving an understanding of the relevant medical facts and  the risks involved.” A more descriptive definition is some-  times employed to capture the nuances of informed consent.  It may thus be defined as “Consent given by a patient after  understanding his/her condition, procedure, risks and alter-  natives based on unbiased information by the medical pro-  fessional in a language and manner which is unambiguous,  lucid.”   Consent [15]  The key historical signposts in the evolution of the Informed  Consent as a valid legal document can be traced to cases  from the US judicial system, though the basic principles find  their roots in English Common law.    e While consent has been a well-known moral requirement  before treatment, it gained legal sanctity only in 1914 with  the case of Schloendorf Vs Society of New York Hospitals.  It set the tone for a legally acceptable premise of self-deter-  mination [15]. Justice Benjamin Cardoza summarized the  basic philosophy in his judgment thus “Every human being  of adult years and sound mind has a right to determine what  shall be done with his own body and a surgeon who per-  forms an operation without his patients consent commits an  assault for which he is liable.”   ¢ However, it was with a series of case in the 1960s and  1970s that self-determination came to be legally binding  as a legal principle and more importantly the importance  of full divulgence by the doctor based on which a consent  can be made became a dictum. Important cases include  the Salgo Vs Le Land Stanford Jr Case (1972) and the   e With the advent of new technology and emergence of new  diseases like HIV, Informed Consent documents are con-  stantly being upgraded to include new medical procedures.   ¢ Informed Consent Document (ICD) in research was  largely evolved due to the World War II atrocities in Nazi  Concentration camps. ICDs in research have been formu-  lated and reviewed by the Nuremburg conference and the  Helsinki declaration. They are closely monitored for con-  tent by organizations such as the WHO, FDA, and the  ICMR in India.    44.4.1.3 Types of Informed Consent [17]  Informed consent may be of two types:   ¢ Implied Consent: It is given by the behaviour of the  patient, such as entering the clinic and opening the  mouth to be examined, etc.   ¢ Oral Consent: It is acceptable for inconsequential pro-  cedures such as examination, taking of impressions, or  even routine low-exposure X Rays, etc.   e Written Consent: While oral consent is an acceptable  consent, it can often be challenged and the consent  cannot often be proved or validated. It is therefore  more binding to give a written informed consent.   Informed Consent for orthognathic surgery is particularly  important because of the nature of the procedure. It is an  elective procedure and the patient often seeks treatment  for enhancement of aesthetics and function. The expecta-  tions are high and therefore the scope for disillusionment  as well.   Orthognathic surgery is a highly skilled procedure in a  complex anatomical area. Treatment often involves multiple  specialists, including orthodontists, anaesthetists, general  dentists, and other surgical specialists like neurosurgeons,  otolaryngologists, or plastic surgeons. In addition to results  falling below expectations, which are largely subjective,  patients may also have morbidity in the form of neurological  deficit, infections, occlusal discrepancy, TMJ problems, and  in rare situations excessive exsanguinations and even death.   Maxillofacial Surgery is a unique speciality of dentistry  and medicine and involves complex procedures and out-  comes. Some of the procedures are cosmetic whereas others  are ablative. Being a surgical procedure involving the mouth,  jaws and face, there are several issues of deformity and  disability.   4. a description of postoperative recovery; possible  complications and known side effects, including  those that are rare.   5. risks associated with the procedure and/or medica-  tions should include alternatives, including the  option of no treatment or surgery at all.    Irrespective of whether the surgery is a minor dento-alveolar  extraction or major reconstructive procedure, it may be cau-  tious to take an informed Consent, which includes chance of  injury or consequences that have disutility for the patient.  While operating as a team there are decisions that can be taken  jointly by the other members in the treatment process, e.g.,  Neurosurgeons or orthodontists. For instance, in orthognathic  surgery, the Informed Consent Document may have several  distinct parts. Gasparini G, Boniello R et al. suggest a three-  part informed consent to include pre-op orthodontics, orthog-  nathic surgery and post-op orthodontic treatment [17].   The informed Consent document may need to include the  following principles and the surgeon and his team can make  appropriate changes to accommodate them. These have  been enunciated by Lord Scarman in the case of Sidaway v  Board of Governors of Bethlehem Royal Hospital [18].    1. The individual should be of adult years (18 years in India)  and sound mind and should have the legal mental capac-  ity to choose what happens to his body.   2. It should offer a choice that entails an opportunity to eval-  uate knowledgeably the options available and the risks  attendant on each (including no surgery option)   3. The doctor should therefore disclose all material risks.  The material risks are determined by the “prudent patient  test,’ which determines what a “reasonable” patient in a  position of a plaintiff (complainant) would attach signifi-  cance to, in coming to a decision on the treatment given.    4. All informed consent must be in a language understood  by the patient (vernacular languages like Tamil,  Malayalam, Bhojpuri, Kannada, etc.)   5. Incase of illiterates, the informed consent must be read to  them in the presence of an independent witness who must  sign on the space provided.   6. In children below 18, a parent or guardian can sign on  behalf of the child.    Recent concerns have suggested that informed consent  should also cover diagnostic tests. It is a common practice in  some countries, including India, to do a routine HIV testing.  These can be undertaken only with an informed consent,  including pretesting counselling. Many countries also insist  on informed consent for multiple high-dose radiation, espe-  cially with the use of CT scan.   ** A standard Informed Consent form is attached and can  be used as a template. Any change depending on local condi-  tions can be added (addendum).   in Oral and Maxillofacial Surgery  Informed consent regulations today are largely governed  by the principles of medical negligence rather than the  tort of battery as in the early days. Any injury, even  expected, may be considered a negligent act if there is no  informed consent, e.g., paresthesia following Impactions  or BSSO. The situation can be defended if the patient was  informed and consent obtained. The civil liability for the  same will be similar to the liability for medical  negligence.   Similarly, Informed consent does not absolve the sur-  geon from liability for negligence, if it is proved that it  could have been avoided if the surgeon had exercised rea-  sonable care.   In short, liability for negligence can be mitigated by an  informed consent, but informed consent cannot totally  absolve a surgeon for an obvious negligent act.   Sometimes, the surgeon may encounter a non-reported or  rarely reported complication despite reasonable care. In  these situations, they can take defence in the principle of  “Act of God!!” These are complications or sequels that may  not have been anticipated by a reasonable surgeon.   ¢ Incapacity of patient by virtue of age or mental status (It  is taken from the guardian/parent).   Informed consent has to be obtained if the patient undergoing  the surgery is the subject of a new device, implant, or tech-  nique which is not a standard one. In India, devices are not  covered by the DCGI (Drug Controller General of India). New  techniques on an experimental basis, particularly in teaching  institutions, must be communicated to the patient and should  be cleared by an Institutional Review Board (IRB) or    Independent Ethics Committee (IEC). The ICD requirements  for research are clearly enunciated in India by the ICMR.   In conclusion, Informed Consent Documentation is an  important and critical part of all treatment plans and often  includes invasive or potentially harmful investigations. A proper  informed consent that is realistic and involves full disclosure, if  the patient is exposed to a chance of injury for which he has no  utility, is a necessary part of all treatment protocols. Informed  consent documents respect the right of patients to take a deci-  sion on how their body is treated based on all available informa-  tion. Itis a moral, ethical and legal obligation to obtain a consent  based on credible information. It also provides a safety net for  the surgeon when unexpected adverse complications occur.    Dentists and maxillofacial Surgeons are often called upon to give  evidence in case of civil or criminal cases. When surgeons are  called upon to give evidence as part of forensic evidence, they  need to have a grasp of the subject. Forensic medicine and odon-  tology have been used in many sensational cases in India, the  Rajiv Gandhi assassination being one of the better-known ones.   Surgeons are often called upon in other more common  situations as well.   2. For opinions regarding the procedures adopted by other  doctors/dentists in cases of alleged negligence.    Expert witnesses are issued summons as discussed earlier  in the chapter. The surgeon is obliged to present himself before  the court at the appointed time. He may be questioned by the  lawyers of the prosecution, defence or the insurance company,  as to the nature of injury and the quantum of disability. The  surgeon is to clearly state his/her opinion without ambiguity  and should remain non-committal about subjects that they are  not sure about. If the surgeon has issued a wound certificate,  the copy of the same will be given to him for reference at the  time of testifying. The witness is to merely state the facts.  They are not expected to involve themselves with the law on  the subject, e.g., Loss of teeth, fracture of jaw, etc. They may  answer truthfully to any other question pertaining to the same.   Today, there are only a few quantified disability criteria  for dental and maxillofacial impairment in India. They  include “The Manual for Permanent Disability” brought out  by the CGHS, WHO, and AIIMS in 1981. A compendium of  suggested dental and maxillofacial deformities/disabilities  has been suggested by Paul G and Thomas S in the published  book Medical Law for the Dental Surgeon [19]. It has been  extensively used in courts of law. If unsure, the surgeon may    state if the injury is grievous or not. He may also elaborate on  the actual disability that the defect might cause.  Examples of grievous injuries are:    Duties of Witness  Failure to appear in court without valid reasons after warrant  has been issued can invite contempt of court.   Exaggeration or false statements given under oath are not  only unethical, but can invite punishment under sec.181,  sec.193.    Negligence is usually a civil wrong or tort. It is the single  most important issue in medical law pertaining to litigation  for damages.   By definition, negligent torts (civil wrongs) are not delib-  erate but rather a failure to act as a reasonable person should  in the conduct of duties to someone whom he or she owes a  duty to.   The liability for negligence can however also be criminal  or statutory.    Negligence as Tort (Civil liability)  It has several formal definitions, but a convenient one by  Alderson explains it rather lucidly as “the omission to do  something which a reasonable man, guided upon those con-  siderations which ordinarily regulate the conduct of human  affairs, would do, or doing something which a prudent and  reasonable man would not do.”   For an act to be considered negligent, the following  aspects must be present, in regard to a surgeon (Box 44.2).   3. That there was an injury resulting from the lack of  care.   4. There should be a proximate or causal relationship  between the negligent act and the resultant injury.    Exceptions to negligence  Normally, carelessness is neither culpable nor a ground for legal  liability, as there is no wrongful intention. However, in medical  negligence, the outcomes have serious implications on the patient  in particular and the public in general. The consequences of neg-  ligence by a surgeon who owes a duty of care are enormous and  the law has imposed a duty of carefulness on the doctor or health  worker in the interest of safe practices. However, there are sev-  eral situations, which do not conform to the strict definition of  negligence. In India, several judicial orders have placed many  actions by doctors outside the ambit of negligence.   A review of Consumer cases (Under the Consumer  Protection Act) shows that some of the situations mentioned  here do not come under medical negligence.    e Not providing an ambulance, due to non-availability of  the service does not constitute a negligent act.   e Any adverse outcome for a procedure done in good faith,  in an emergency, beyond the call of duty, is not consid-  ered a negligent act. It is also called the Good Samaritan  Act in some countries.   ¢ Mere patient dissatisfaction with progress of treatment or  desired relief cannot be construed as negligence.   e Giving precedence of one patient over the other based on  clinical risks or emergencies is not negligence.   e A fee, being perceived as exorbitant by the patient, is not  negligence.   ¢ Non-availability of a doctor outside his or her working  hours may not constitute negligence.   The degree of carelessness for a particular profession  depends on the risk that it poses to the person who is exposed  to it.   Professional standard of care is therefore that standard of  care or skill that is laid down by a body of professionals on  behalf of the medical profession and which a surgeon or phy-  sician is expected to bring to his duty.   If skill and knowledge fall below this established stan-  dard, it will be considered to be negligent. A body of profes-  sionals can establish this standard by publication in books,  reports of scientific studies, or by protocols established by  them, e.g., text books, journals and protocols created by pro-  fessional associations. Today, evidence-based science is the  hallmark of best practices and is defined by the quality of  evidence established through Randomized Clinical Trials  (RCT) and meta-analysis of peer-reviewed publications.   When there is a difference of opinion on technical mat-  ters, an alternate method recognized by another body of pro-    fessionals will be acceptable as a valid procedure and will  not be considered as negligence. This is ascertained by the  application of Bolam’s law [20], which recognizes reason-  able difference of opinion based on credible evidence or  experience among peer professional groups.   The Bolitho test uses a different legal parameter and has  undermined the usual dependence on the Bolam test. The  Bolitho test goes beyond dependence on just two opinions  and looks at credible scientific evidence as more important  than mere difference of opinions.   In this context, it is important to discuss the semantics of  customary and acceptable.   A professional cannot adopt a procedure merely  because it is customary. Customary standards have been  looked at critically because it does not provide incentive  to adopt better practices. Because a particular procedure  has been done for many years does not make it an accept-  able practice. An acceptable practice, on the other hand, is  not only time tested but also scientifically sound. An  acceptable practice is usually the product of evidence-  based science as opposed to customary practice, which is  either anecdotal or proven to be inadequate or irrelevant  by scientific scrutiny.   An often-quoted legal principle is that “The skill, dili-  gence, knowledge, means and methods are not those that are  ordinarily or generally or customarily exercised or employed,  but those that are reasonably exercised or applied, negligence  cannot be excused on the ground that others practice the  same kind of negligence.”   It may therefore be said that a “health worker is under a  duty to use that degree of skill which is expected of a reason-  able competent practitioner in the same class to which he  belongs, acting in the same or similar circumstances.” The  Supreme Court has defined this duty in the case of Indian  Medical Association Vs V.P. Shanta [21] as “In general a pro-  fessional man owes to his client a duty in tort (civil wrong)  as well as in contract to exercise reasonable care in giving  advice or performing services.”   Importantly, the court held that this standard should be  outlined by the medical profession and it is not the duty of  the “lay courts” to decide on what constitutes “standard”  care. Negligence, in these situations, may be dependent on  the locality, availability of facilities, specialization of the  doctor, proximity to specialists and advanced technology.  However, it is important to remember the dictum “no man is  bound in law to be a good surgeon, but all men are bound not  to act as a surgeon until he is good and capable as such.”   The foregoing dictum indicates that a physician or sur-  geon should not venture to do a procedure unless he is trained  and competent in performing it. Merely admitting that he  had inadequate experience is no legal remedy. In other  words, it is not legally wrong to be ignorant, but it is legally  wrong to act in ignorance.   This is a classical test widely used in the United Kingdom.  The Bolam test is an acceptable test used by the National  Health Service of the U.K. when a situation of negligence  presents itself as observed in the landmark case of Bolam  Vs Friern Hospital managing committee. (1957) 2 AIIER  118.   The Bolam test establishes that standard procedures be  the basis of treatment. Importantly, it provides for alternate  management protocols. If there is more than one school of  thought, both alternates will be acceptable as a standard.   In a minority judgment comments in Bolitho, it was  emphasized that the word “responsible” in the traditional  formulation of the Bolam test meant that responsible  practice is that which withstands the scrutiny of “logical  analysis” from a judicial perspective. Today, courts are  increasingly scrutinizing risk analysis from a patient view  point, which undermines the traditional view point of only  the care giver.   While both words have almost the same meaning, there is a  small difference. A careless person may not think of the  eventuality while being careless. On the other hand, the reck-  less person is fully cognizant of the injury that his act may  cause, but still takes the risk of possible injury. The former is  passive, whereas the latter is an active act. Both acts are how-  ever are not intentional and is therefore often used to describe  negligence.    Standards of Care in Hospitals  Legal standards applicable to hospitals are somewhat similar  to those required of doctors or other health workers.    1. The facilities of a hospital should be that of a reasonable  hospital engaging in similar type of health care.   2. The Hospitals should maintain standards laid down by  statutory provisions (if available). In India, there are now  basic standards for all medical establishments, which are  defined by a legislated statute called the Clinical  Establishment Act. It provides for the basic requirements  of different categories of hospitals and the role of person-  nel in providing standard care.    In addition, the hospitals may be answerable for the neg-  ligence of their doctors, nurses and other health workers  through what is called vicarious liability.    In some situations, negligence arises fully or in part due to  the patients or the complainant’s fault. As the patient, wholly  or partly, contributes to the negligent act, it is called con-  tributory negligence.   The standard to be adopted to assess contributory negli-  gence is somewhat similar to the standard adopted for the  doctor. It may be said that ‘contributory negligence is when  a competent adult (patient) may be negligent by contribution  when his conduct falls short of the degree of care that society  expects a reasonable person to do or not to do for his own  safety’. This would obviously preclude children and men-  tally incapacitated adult.    1. When a patient refuses to take a prescribed medication  resulting in postoperative infection.   2. A patient who removes inter-maxillary wiring on his own  resulting in non-union.   4. Vicarious (Liability passed on to hospital or employer)  Negligence can be remedied depending on what legal pro-    The punishment under the law of Tort (Tortious liability) is  unliquidated damages, i.e. whatever damages the judge wishes  to award depending on injury, circumstances and other consid-  erations like age, earning potential, profession, etc.   If an implied agreement was made between doctor and  patient, then the remedy would be as specified in the con-  tract. The judge may order a specific performance to do or  not do something he has agreed to. However, guarantees for  treatment are against ethical guidelines for treatment and it is  not applicable in medical law.   If the complainant seeks punitive action against the doc-  tor, he may file a criminal case under the relevant statutes.  The Indian Penal Code for example, has provisions to punish  doctors for death or disability. The remedy under criminal  law is always in the form of a punishment (Penal). It may  involve imprisonment or fine or both. Rarely, the court can  order compensation or specific performance as well. Criminal  law sees negligence as a crime against the state and not just  against the plaintiff.    Doctors may also be liable under professional statutory  laws governing the practice of the profession. In India, stat-  utory bodies such as the Medical Council of India or the  Dental Council of India can prescribe punitive action in  accordance with laid down laws. The laws can be initiated  only against persons registered under the particular statu-  tory body. The Medical Council of India, for instance, can-  not take action against a dental-qualified maxillofacial  surgeon.   In some instances, a doctor may not have to answer for his  negligence directly. The hospital or establishment employing  him may have to answer to the allegation to negligence. This  is called vicarious liability and is usually relevant to salaried  employees who work for a contract of services and not a con-  tract for services.   However, in practice, for the sake of regularity, it may be  said that all permanently or part-time employed doctors are  only vicariously liable. However, if the patient is admitted by  a doctor in his personal capacity, then the doctor will be per-  sonally liable.   In a doctor patient relationship, an implied contract is estab-  lished when a doctor accepts a patient for treatment. A breach  of any aspect of this implied contract may amount to negli-  gence when the doctor is under duty to    1. Treat with care  2. Continue to treat and not terminate until patient is cured  or the patient discontinues treatment.    This may be considered the contractual nature of medical  liability. However, Medical ethics does not provide for a  written contract, which can be violated as in the case of a  commercial transaction. So any liability based on breach of  an implied contract will essentially lie within the realm of  tortious liability.   Written contracts with promise to cure, failing which a  refund is assured is against the ethics of medical or dental  practice. It is this author’s view that such contracts can be  technically void, considering the ethical and legal issues  involved.   Tortious Liability is usually dealt with in Civil Courts.  In India, medical negligence comes within the ambit of  the Consumer Protection Laws established to provide  speedy relief to plaintiffs seeking redressals for goods and  services that fall short of standards. The Consumer  Protection Act defines medical care as contract for ser-  vices, which makes doctors and hospitals liable under the  Consumer Protection Act of 1986. The Consumer Courts  are quasi-judicial legal redressal forums established for  speedy justice. They are tiered under the District, State  and National Forums depending on the place of the cause   This liability normally lies with an identifiable individual or  groups of individuals. However, recent trends indicate that  Hospitals also may be held vicariously liable just as in civil  liabilities.   Criminal liability is penal and involves punishment in the  form of imprisonment or fine or both. Criminal negligence is  considered to be a crime against society and not just the  aggrieved party and is in violation of penal codes of coun-  tries. In India, it is a violation of various sections of the  Indian Penal Code 1868 (amended several times).   The important offences inviting criminal liability with  regard to negligence are:   2. Sec 336 (IPC) An act endangering the life of a person  (even if there is no injury), e.g. conscious sedation with-  out essential monitors or oxygen, even if no harm is  caused.   4. Sec (338) (IPC) A rash or negligent act resulting in griev-  ous injury, e.g. fracture of jaw during extraction due to  excessive or improper force or avascular necrosis follow-  ing osteotomy.    While these are the common sections under which a doc-  tor may be liable, other sections also apply. Any offence  against the human body (Sec 299 to Sec 377) or offences  against property (Sec 378-462) can be used against doctors,  e.g. abetting suicide, causing miscarriage sec 312—316 (sub-  ject to exemption from the Medical Termination of preg-  nancy Act 1971), etc.   Sections 78, 80, 81, 87, 88 are directly or indirectly rele-  vant to the medical practitioner. Some can be used in defence  of the doctor accused of negligence. Section 88 for instance  is an act done in good faith not intended to cause death. It is  a good defence in emergency care. Sections 86 and 87 IPC  are in respect to harm or death caused by an act not intended  to cause harm or death and is done with consent in the best  interest of patients. Section 499 deals with defamation. It can  be used by doctors to counter malicious charges by patients  intending to spoil the good name of the doctor by frivolous  or vexatious charges. It can also be used by patients as a  criminal violation of confidentiality statutes. For example,  revealing HIV status when the patient is not likely to be a  public health hazard.    It is important to understand some terms in connection  with criminal liability (Box 44.3).   e Non-Cognizable: An arrest can only be made by a  judicial warrant.   ¢ Bailable: the arresting officer can provide bail. Bail  is a matter of right and has to be given unless the  officer apprehends that the accused may abscond or  tamper with evidence.   ¢ Non-Bailable: Bail can be secured only from a  magistrate. Heinous and violent crimes fall in this  category, e.g., if there is a significant risk that the  offender may commit further crimes, abscond or  tamper with evidence.   ¢ Compoundable: A crime in which a compromise  between the suspected offender and the victim or  his attendant can be worked out it is said to be  compoundable   e Non-Compoundable: If the crime is against society  and is of a serious nature, no compromise can be  made between the accused and the victim. These  cases are said to be non-compoundable.   e Sec 304 A is cognizable, bailable and non-com-  poundable. It can be punished with imprisonment of  either description for a term of 2 years or fine or both.   e Sec 337 and 338 are cognizable, bailable and com-  poundable. Sec 337 may attract an imprisonment up  to 3 months and a fine up to Rs 250/ or both. Sec  338 can involve imprisonment up to 2 years and a  fine up to Rs 1000/ or both.    It is important for the surgeon to be aware of these liabili-  ties. It is also important for him to understand his rights. For  example, bail is a matter of right in the foregoing situations  and it is to be given by the police officer attempting to arrest  a medical professional. Bail is granted on the surety given by  the doctor or a colleague. A doctor can give surety on his  own reputation. The burden of providing reasons for refusing  bail rests on the police officer and he will have to give con-  vincing reasons for not granting bail.   In a landmark case referred to as the Jacob Mathew Case  (2002), the Supreme Court of India has prevented arbitrary  arrest and detention of doctors even in case of death or serious    disability, as a part of treatment. Criminal liability and arrest  can only be made on the basis of a credible Medical Board  opinion duly constituted or recognized by the Government.    Statutory Liability  A doctor or nursing home is liable if there is any infringe-  ment of Statutes (rules). They then become accountable to a  statutory body. The liability depends on the kind of infringe-  ment and the provisions in the statute to deal with it. There  are many statutes dealing with practice of Doctors and  Dentists, as well as Hospitals. Recently, the newly legislated  Clinical Establishment Act provides guidelines for the whole  of India.   Doctors and dentists may also be liable to other statutory  laws such as The Pollution Control Board and the Drugs and  Cosmetics Act, etc.   It is important for the doctor/dentist to know the legal pro-  cedure involved in medical negligence. The legal procedure  is slightly different for civil negligence, criminal negligence,  and negligence under the Consumer Protection Act.   To understand legal procedures, one must be familiar with  some of the procedural laws. They are,   2. Criminal Procedure Code  3. The Indian Evidence Act  4, The Limitation Act    The Evidence Act  It is a very important procedural law. There are three con-  cepts in Evidentiary Law.   The “facts in issue” are those that have to be explicitly  proved. The facts in issue are proved by bringing into evidence  the relevant facts. Sections 6-55 deal with these relevant facts.    The person who has to legally bring in evidence to prove  or disprove a fact is said to have the ‘burden of proof’”.  When one has the burden of proof he has:    1. The burden of establishing a case  2. The burden of introducing evidence.    The general rule (with some exception) is that the onus of  proving any particular fact lies with the party who alleges it  and not with the party who denies it. In other words, the onus  of proof lies with the complainant and not with the  defendant.    1. Direct Evidence  2. Circumstantial Evidence  3. Res ipsa loquitor (The matter speaks for itself)  e Another aspect of evidentiary law is standard of proof.    The standard of proof in civil cases can be based on prob-  ability and circumstantial evidence. However in a criminal  case, the standard of proof is more stringent and should be  beyond reasonable doubt as sanction in criminal law is more  severe and penal in nature.    It is the statute dealing with the time limit for various  suits, appeals, bail application and other legal actions.    This refers to the incident, which has necessitated a legal  process. Limitation period begins as soon as the cause of  action takes place. The period of time varies according to the  suit and it is given in the schedule of limitations.   For appeals, the day of judgment marks the beginning of  limitation period after giving time for obtaining the copy of  decree (Judgment Order). This will not include ‘writs’ as the  limitation Act does not apply to them.   If a suit or appeal is made after the statutory limitation  period, the court may reject the petition on grounds of being  barred by limitation. The court may however accept a peti-  tion even if it is barred by limitation, if it is satisfied that the    delay was unavoidable. However, in criminal cases, the Act  does not provide a period of limitation. Criminal proceed-  ings can be instituted at any time after the offence has been  committed. However, as per the guidelines given in Section  468 of CrPC, the limitation periods run thus:   (b) 1 year for offences punishable with imprisonment up to  1 year.   (c) 3 years for offences punishable with imprisonment up to  3 years (not less than | year).    If the limitation period ends on a day when the court is  closed, then the next working day is included as the limita-  tion period. It may therefore be said that a suit should be filed  as soon as the cause of action occurs.   Any party who wishes to approach a court with litigation has  to pay a court fees with some exceptions like the Consumer  Court. Each state may have a different court fee structure. In  a suit for money, the fee is usually computed based on the  amount claimed by the plaintiff. Court fees are paid in the  form of Stamps, which may be adhesive or impressed or both.    This chapter is unique as most textbooks do not address  issues pertaining to law and ethics in practice.   The maxillofacial surgeon is often confronted with ques-  tions on their remit and scope of work as it overlaps with  several other specialties and is constantly in conflict with  issues of qualification and areas of competence. The sections  on these issues will throw light on their practice privileges in  addition to dealing with litigation for medical negligence,  which has become all pervasive.    Please initial on each page after reading. If you have any questions, please ask your  doctor BEFORE initialing.    Have you had any of the following Problems? Please tick YES or NO    GENERAL PROBLEMS:  * Cold, cough ----------------------------------------- Yes \No  © Fever, --------------------------2 2222-2 on nnn enna anna Yes \No  ¢ Sinusitis ------------------------------------------------ Yes \No  (If Yes, when was the last episode )  RESPIRATORY PROBLEMS:    * Nasal obstruction  - Asthma  ¢ Shortness of breath  ¢ Tuberculosis ( TB).  * Bronchitis.  - Emphysema  - Lung diseases.  (If Yes, when was the last episode )    Heart attack  Heart murmur  Pacemakers  Rheumatic fever  Irregular heart beat  Infective endocarditis .  Angioplasty / Angiogram.  Bypass surgery.  (If Yes, mention the details of medication, Procedure date & last visit  to the Physician  ee D    (If Yes, mention the details of medication, Procedure date & last visit to  the Physician    the Physician _  )  ARTHRITIS:  (If Yes, mention the details of medication, Procedure date & last visit to  the Physician a  )  RADIOTHERAPY:  (If Yes, mention the details of Procedure date & last visit to the  Physician a  )    the Physician  a  Date of last physical exam: Date of last ECG:    Are you pregnant: YES/ NO(If yes specify the trimester )  Are you breast feeding: YES/ NO(If Yes, since how long )  Have you been under the care of physician during last 2 years?    Are you taking medicine of any kind: YES/NO  (if Yes, For what & since how long )    Do yousmoke YES/NO (If yes, How long how many )  Do you consume alcohol YES/NO (If yes,How long how   Do you chew Tobacco/ Areca nutYES/NO (If yes,How long how  much )    General anesthetic....YES/NO — Barbiturates....YES/NO  Any other allergies in specific  Do you wear dentures... YES/NO    Have you had any of the following ? Please check YES or NO  Yes No    Recurrent illness( Within one year)  Cough, cold , flu(Within 2 months)  Nose obstruction  Shortness of breath  Lung disease  Asthma  Bronchitis  Emphysema  Heart trouble  Chest pain  Heart attack  Irregular heart heat  Yes No  Heart murmur  Rheumatic fever  Scarlet fever  Arthritis  Artificial joints  Cortisone    Yes___— No Are you pregnant?  Yes _ No Have you been under the care of physician during the last two years?  Yes No Have you been made unconscious for an operation?    Yes No General Anesthetics Yes No Barbiturates  Yes No Do you wear dentures?  Yes___— No Do you wear contact lenses   TREATMENT PLAN) fscuccisisascacsasisnagaaes ernadanadeacoasaaeepencetacas  My doctor has explained to me that there are certain inherent and potential  risks and side effects associated with my proposed treatment and in this  specific instance they include, but are not limited to :   1. Post-operative swelling and discomfort that may require several days of  recovery.   5. Stretching of the corners of the mouth that may cause cracking or bruising  and may heal slowly.   6. Restricted mouth opening during healing sometimes related to swelling and  muscle soreness and sometimes related to stress on the jaw  joints(TMJ),especially when TMJ problem already exists.   7. A decision to leave a small piece of root in the jaw when its removal would  require extensive surgery or risk of other complications.   Fracture of the jaw (usually only in more complicated extraction or surgery)  Injury to the nerve adjacent to teeth, resulting in pain numbness tingling or  sensory disturbances on the chin, lip, cheek, gums or tongue and which may  persist for several weeks, months, or in rare instances permanently.   10. It has been explained that during the course of treatment unforeseen    conditions may result that may require change in the procedure, | authorize  my Doctor to use professional judgement to perform such additional    It has been explained to me and | fully understand that a perfect result is not  or cannot be guaranteed.  | have read and fully understood the above and discussed this operation  and alternative treatment with . He has given me  ample opportunity to ask questions about specific points and has    PLEASE ASK YOUR DOCTOR IF U HAVE QUESTIONS CONCERNING  THIS CONSENT FORM    Please initial on each page after reading. If you have any questions, please ask your  doctor BEFORE initialing.    1. I hereby authorize Dr. and assistants to treat the  condition described as    2. The procedure offered to treat the condition has been explained to me and I understand the  nature of the procedure to be:    3. I understand that incisions will be made in my mouth for the purpose of placing one or  more endosteal root form structures (implants) in my jaw to serve as anchors for a missing  tooth or teeth replacement or to stabilize a crown (cap), bridge, or denture. I acknowledge  that the doctor has explained to me the procedure, including the number and location of the  incisions and the type of implant to be used. I understand that the crown, bridge or denture  that will be attached to this implant(s) will be made and attached by  Dr. and that a separate charge will be made by the office.    4. I understand that the implant(s) may need to remain covered by gum tissue for at least  three months before being used and that a second surgical procedure may be needed to  uncover the top of the implant. No guarantee can be or has been given that the implant(s) will  last for a specific time period. It has been explained to me that once the implant is inserted,  the entire treatment plan must be followed and completed on schedule.If the planned schedule  is not carried out , the implant(s) may fail.    5. I have been informed of possible alternative methods of treatment (if any), including    I understand that other forms of treatment or no treatment at all are choices that I have and  the risks of those choices have been presented to me.    6. My doctor has explained to me that there are certain inherent and potential risks and side  effects of any surgical procedure and in this specific instance such risks include but are not  limited to:    A. Post-operative discomfort , Pain and swelling that may require several days of at- home  recuperation.    D. Post-Operative infection and inflammation of soft tissues around the implant that may  require additional treatment.    E. Stretching of the corners of the mouth that may cause cracking and bruising and may heal  slowly.   F. Restricted mouth opening for several days; sometimes related to swelling and muscle  soreness and sometimes related to stress on the jaw joints (TMJ).   G. Injury to nerve branches in the lower jaw resulting in numbness, pain or tingling of the  chin, lips, cheek, gums or tongue on the operated side(s). These symptoms may persist for  several weeks, months or, in rare instances may be permanent.   H. Opening into the sinus (a normal bony chamber above the upper back teeth) requiring  additional treatment. If the sinus is intentionally entered (sinus-lift procedure with grafting),  there may be several weeks of sinusitis symptoms requiring certain medications and  additional recovery time.   I. Fracture of the jaw or perforation of thin bony plates.   J. use of other materials which may have to be removed at a later date:   L. implant or prosthesis fracture, or loss of the implant due to rejection by the body.    7. It has been explained to me that during the course of surgery unforeseen conditions may be  revealed which will necessitate extension of the original procedure or a different procedure  from that set forth in paragraph 2 above. I authorize my doctor and his staff to perform such  additional procedures as are necessary and desirable in the exercise of professional judgment.    8. I understand smoking is extremely detrimental to the success of my implant surgery. I  agree to cease all forms of use of tobacco for 2-3 weeks after surgery, including the later  uncovering procedure (when necessary), and to make a strong efforts to give up smoking  entirely.    10.ANESTHETIC RISKS include: discomfort, swelling, bruising, infection, prolonged  numbness and allergic reactions. There may be inflammation at the site of an intravenous  injection (phlebitis which may cause prolonged discomfort and / or disability, and may    require special care. Nausea and vomiting, although are rare, may be unfortunate side effects  of IV anesthesia. Intravenous anesthesia is a serious medical procedure and, although  considered safe, carries with it the risk of heart irregularities, heart attack, stroke, brain  damage or death.    A. Because anesthetic medications cause prolonged drowsiness, you MUST be accompanied  by a responsible adult to drive you home and stay with you until you are recovered  sufficiently to care for yourself. This may be up to 24 hours.   B. During recovery time (24 hours) you should not drive, operate complicated machinery   or devices or make important decisions such as signing documents, etc.   C. you must have a completely empty stomach. It is vital that you have nothing to eat or drink  for eight (8) hours prior to your anesthetic. To do otherwise may be life-threatening.   D. However, it is important that you take any regular medications (high blood pressure,  antibiotics, etc.) Or any other medications provided by this office, using only a small sip of  water.    11. I understand that no guarantee can be promised and I give free and voluntary consent for  treatment.    My signature below signifies that all questions have been answered to my satisfaction  regarding this consent and I fully understand the risks involved of the proposed surgery and  anesthesia. I certify that I speak, read, and write English.    BEFORE SIGNING, PLEASE ASK YOUR DOCTOR IF YOU HAVE ANY  QUESTIONS CONCERNING THIS CONSENT FORM.    Please initial on each page after reading. If you have any questions, please ask your doctor  BEFORE initialing.    Orthognathic surgery is being planned for you, and it is important that you understand the  benefits and risks of such surgery. This is NOT minor surgery and you have the right to be fully  informed about your condition and the recommended treatment plan. The disclosures in this  consent are not meant to alarm you, but rather to provide information you need in order to give  or withhold your consent to the planned surgery.    1. Thereby authorize Dr. and staff to treat the condition  described as:    2. The surgical procedure planned to treat the above condition has been explained to me and I  understand the nature of the treatment to be:    3. [have been informed of possible alternative forms of treatment (if any), including:    4. My doctor has explained to me that there are certain potential risks and side effects of the  surgery planned, some of which may be serious. They include, but are not limited to:    A. Facial and jaw swelling after surgery, usually lasting several days.   B. Bleeding, both during and after surgery, which may sometimes be severe  enough to require blood transfusion. I have been informed about the  opportunity for blood donation before surgery so that, my own blood may  be transfused back to me (auto transfusion) if necessary.   Allergic reaction to any of the medications given during or after surgery.   Delayed healing of the bony segments; rarely requiring a second surgery and/or  bone graft to repair.    E. Relapse: the tendency for the repositioned bone segments to return to their  original position, which may require additional treatment, including  surgery and/or bone grafting.   F. Bruising and discoloration of the skin around the jaws, eyes and nose. Possible  Hematoma at injection site .   G. Diminished sense of smell (anosmia) in the upper jaw surgery.    H. A change in cosmetic appearance. Although this is primarily a procedure to  restore jaw function, I am aware of some expected change in my appearance. I  understand that certain cosmetic changes may not be totally predictable. There may  also be changes in speech patterns which may require additional treatment.    I. Loss of feeling, pain or a tingling numbness in my chin, lips, tongue, gums, or  teeth which occurs in a significant number of patients. Loss of taste  sensation in tongue and palate . These symptoms may last for several days,  weeks or months. I have been told that there is some chance that it may be  permanent.   Scarring from external skin incisions if certain rigid fixation methods are used.   M. In certain cases where bone cuts may be made in the marrow space between  teeth, there is the possibility of devitalization of those teeth which may  require later root canal procedures, and may result in the loss of these  teeth.   N_ Fracture of the maxilla and mandible due to improper mobilization or incomplete   O. Inupper jaw surgery, the sinus will be affected for several weeks, and there may   bleeding from nose in postoperative period. There may be a need for further sinus   P. Post-operative infection which may cause loss of adjacent bone and/or teeth and  which may require additional treatment for a prolonged period of time.   Q Change in position of the jaw joints (TMJ) which may cause post-operative   surgery, there may be no improvement and even some worsening of these symptoms  after surgery.   R. Stretching of the corners of the mouth with resulting discomfort and slow   S. | Inflammation of veins (phlebitis) that are used for IV fluids and medications,  sometimes resulting in pain, swelling, discoloration and restriction of arm  or hand movement for some time after surgery.   T. Hypernasality of voice due to swelling of nasal mucosa in immediate post  operative period. Diffculty in swallowing and speech in cases of cleft  patients due to velopharyngeal incompetence.    U_ I consent to being photographed (head and neck region only) before and  After surgery and during the operation to be performed.    These photographs may be used for medical, scientific or educational purposes, provided my  name is not revealed by the pictures    5. General anesthesia will be used for this surgery and I have been told of the risks,  including bronchitis, pneumonia, hoarseness or voice changes, cardiac irregularities, heart attack  or death. I am aware of the importance of not having anything by mouth (including clear liquids  unless specifically authorized by my doctor or anesthesiologist) FOR EIGHT (8) HOURS  PRIOR TO AND (8) HOURS AFTER SURGERY . TO DO OTHERWISE MAY BE LIFE-  THREATENING!    6. I realize the importance of providing true and accurate information about my health,  especially concerning possible pregnancy, allergies, medications and history of drug  or alcohol use. If I misinform my doctor I understand the consequences may be life-  threatening or otherwise adversely affect the results of my surgery.    If my teeth are wired together after this surgery, I understand there are certain associated risks  and complications: oral hygiene will be diminished, there may be resulting gum disease, my  teeth will feel slightly loose for some time after the wiring, compromised nutrition and there is  always some concern about airway obstruction. I agree to carry wire cutters with me at all times  when my jaws are wired and to avoid the use of alcohol and other activities that may cause  nausea or airway problems.    I have informed my doctor about my use of birth control pills. I have been advised that certain  antibiotics and other medications may neutralize the preventive effect of birth control pills,  allowing for conception and pregnancy. I agree to consult with my personal physician to initiate  additional forms of birth control during the period of my treatment, and to continue those  methods until advised by my personal physician that I can return to the use of oral birth control  pills.    By signing this consent form, I acknowledge that I have read it completely and understand the  procedure to be performed, the risks, and the alternatives to surgery. I have had all my questions  answered to my satisfaction. I was under no pressure to sign this form and have made a  voluntary choice to proceed with surgery. The fee for services has been explained to me and is  satisfactory and I understand there is no warranty or guarantee as to the result and/or cure and  that my condition may return or become worse. I certify that I speak, read and write English.    ORAL AND MAXILLOFACIAL SURGERY  CONSENT FOR TREATMENT FOR REPAIR OF TEMPORO-MANDIBULAR JOINT    Please initial on each page after reading. If you have any questions, please ask your doctor  BEFORE initialing.    pathology (disease) that exists in my right and/or left temporomandibular joints  (lower jaw joint).   I understand that my condition of limited or compromised function and/or pain  may be secondary to a number of possible processes including, but not limited to    Chronic pain  Material failure ( foreign body reaction)  Frey's syndrome (sweating over temporal region on operated side)   Intracranial injuries ( Dural tear, cerebrospinal fluid leak)  Post operative maxilla-mandibular fixation  Objectionable scar formation.    I understand that the surgery to be performed is an exploratory procedure and the    treatment rendered at that time will be based on the findings during surgery.    I (we) understand that my surgeon may discover other or different conditions    I (we) understand that no warranty or guarantee has been made to me as to a result  or cure. I (we) also realize that the following risks and hazards may occur in   1. Facial nerve paralysis with inability to close eyelid on the affected side.  2. Inability to wrinkle the forehead.   4. burning sensation of eye due to inability to close eyelids    7. Resultant malocclusion (incorrect bite) and limited opening of jaw.  8. Lack of improvement or worsening of pain and jaw dysfunction.    Please initial on each page after reading. If you have any questions, please ask your doctor  BEFORE initialing.    My doctor has explained to me that there are inherent and potential risk and side effects  associated with my proposed treatment and in this specific instance, but they are not limited to    Damage to or loss of teeth in the area of trauma or fracture, loss of vitality of those teeth  with requirement for future root canal therapy, loss of dental restoration, accidental  swallowing or aspiration of tooth or foreign object, devitalization of bone and soft tissue  in the area of trauma which may result in some loss of tissue.   Unusual procedures required during surgery such as incomplete removal of tooth, which  endanger adjacent vital structures.   Post operative swelling, discomfort, bruising, bleeding, hematoma (blood clot), wound  infection or dehiscence, sinusitis and limitations of function, any of which require further  care.   Adverse or allergic reactions to medications or anesthesia causing multiple side effects,  some of which may be serious and require additional care or hospitalization.   Reaction to foreign material which may have been introduced into the wound by the  trauma, or "tattooing" of the skin or mucosa from particles of foreign material   Change in occlusion (bite) and jaw function after treatment; secondary problems of the  jaw joint (TMJ) which may be prolonged, or even permanent, and which may require  future treatment.    . Possibility of otologic (ear related) complications such as perforation, infections,    decrease in function of parotid gland( one of the gland responsible for saliva  secretion),formation of fistula over preauricular& retromandibular region(areas of lateral    surface of face), mandibular hypomobility in long term experience, ankylosis of TMJ  during surgeries of TMJ joint.   8. Scarring either inside or outside of the mouth, depending on the nature and force of the  trauma and the locations of certain incisions required in treatment.   9. Facial muscle weakness particularly of the lip, eyelid or other muscles of expression  caused by injury to motor nerves in the area of the trauma. Such weakness may be partial  or total and may be temporary or permanent.    10.Sensory nerve injury causing pain, numbness, or other sensory alterations anywhere in  the mouth, tongue, cheek, lip, and areas of facial skin which may be temporary or  permanent.   11. Wiring the teeth together during the time required for healing of bone fractures will  significantly reduce oral hygiene effectiveness, which may then lead to or worsen  periodontal (gum) disease, bleeding gums, discomfort and loosening of teeth. Following  treatment for facial injury, any such conditions must be treated. Jaw wiring will decrease  normal diet and cause temporary weight loss.   12.Certain wires, screws, plates, splints or other fixation devices may be introduced, and  some may require later removal.   13. Unusual effects related to hardware used such as metal sensitivity, Infection ,screw  fracture, plate fracture or plate exposure.   14. Non-union or malunion of bony fractures, possibly requiring re-treatment. Some cosmetic  or functional deformity may occur in areas adjacent to the trauma or repair    I understand that additional injury may be discovered during treatment that might  necessitate a change in approach or a different procedure from those explained above and  I authorize my doctor to perform such procedures that are necessary and advisable in the  exercise of professional judgment.    I understand that this is complex treatment and there can be no guarantee of complete  resolution of my present symptoms or jaw/teeth/facial bone injury. Occasionally there  may be increased symptoms post-operatively (for example, numbness). I also understand  that additional treatment may be necessary post-operatively, including (but not restricted  to) physical therapy, reconstructive dentistry, orthodontics, retreatment of bone fractures  including bone grafting, removal of certain fixation devices, or TMJ treatment. I agree to  cooperate with my doctor's recommendations during treatment, realizing that lack of  cooperation will result in a less-than-optimal result.    I have discussed my past medical history with my doctor and have disclosed all diseases  and medications, including alcohol and drug use (past and present).    I have had an opportunity to have all my questions answered by my doctor that all blanks  on this form were filled in prior to my signing, and I certify that I understand English. My  signature below signifies that I understand the surgery and anesthetic that is proposed for  me, together with the known risks and complications associated. I hereby give my  consent for such surgery and anesthesia I have chosen.    Here is the Consent for informed consent and illiterates. This as per the  standard requirement. You can dilute it or modify it.   1. All consent forms should be in the language of the majority of the population.  Therefore it must be in the Vernacular of that region plus English or any other  popular language. The English Consent form should be translated to the local  language. There are two ways of doing it so that the essence and meaning are  not lost.   A. Ethical committee approved consent forms in order to remain valid will need  ‘back translation’. The suggested or approved consent form must be translated  into the vernacular. The thus translated matter must then be translated back to  the original English by another person. Then the original and the ‘back  translated versions are compared. If the meaning remains unchanged then the  translation is accepted. Please note that this is required only in approved consent  forms in research etc. In the clinical setting the AOMSI consent for is only a  template and such rigorous measures may not be necessary.   B. Alternately the approved consent in English can be translated by a  Government approved translator ( usually a University translation department).  E.g. The Tamil University in Tanjore does approved translations.    2. For obtaining Informed Consent of illiterate persons the Consent form can be  read out to the person giving consent in the language he/ she understands in the  presence of an independent third party or relative of patient who should be  literate. The consent form is then signed and attested by the independent witness  in addition to signature or thumb impression of the consenting person.   3. In case of children below 18 years, the parent or legal guardian can sign on  behalf of the children. However, child rights activists and the new law in several  countries may require a consent (particularly in older children who can  comprehend issues). Technically, in India, children below 18 are considered to  be 'not legally competent.    4. In mentally retarded or persons incapable of consenting due to mental  incapacity, the parent or legal guardian (if unavailable -institutional heads of  organizations taking care of them can sign on their behalf).   5. In hearing impaired illiterates the consent must be explained by sign language  or any means that is used for communication to translate the document. It needs  third party attestation. Similarly, in visually impaired persons the consent can be  obtained through Braille or by oral communication with third party attestation.    Today, in many countries video recorded informed consent procedures are  utilised. It may become mandatory in India too.    Caveat: informed consent, however carefully taken can be challenged on the  grounds of being an unequal contract influenced by fiduciary relationship in  doctor- patient relationship.    The above is my personal opinions based on experience and the use of consent  approved by Ethiconsult Services of which Dr George Paul was a member  secretary. It can be modified as per personal perception of what constitutes  adequate consent.    This form is primarily used when any recommended treatment is refused by a patient.  (It may also be used for patients with TMJ implants who remain both asymptomatic  and without imaging changes in joints and who, contrary to FDA and AAOMS  guidelines, do NOT wish to have TMJ implants removed)    I have been informed by DRof my condition and the recommended treatment  consisting of :    Afterconsideringthetreatment possibilities offered, and having the benefits and risks  of each explained to my satisfaction, I have voluntary chosen to :-    | understand that my decision is contrary to my doctor’s recommendation and that my  condition may significantly worsen as a result, may require additional therapy   additional therapy/ or hospitalization, and in rare circumstances may be life   threatening. | AGREE TO RETURN TO THIS OFFICE FOR PERIODIC  MONITORING OF MY CONDITION AS scheduled by my doctor.    I realize that I may consider my decision at any time by notifying my doctor.   Form and function are the quintessence of human life.  Disability and deformity are interruptions to this harmony.  Disability/deformity may be congenital or acquired.  Governments have a social responsibility to mitigate such  afflictions by creating an environment for re integrating them  into normal social life. Most welfare states provide benefits for  persons with disability.   Disability can also be caused by accidents, interpersonal  violence and iatrogenic causes. These situations have legal  overtones and often require compensation in some form.  Benefits and compensation can only be calculated if the dis-  ability is quantified. Orthopedic disabilities in Civil and  Military life have been calibrated and quantified. Similarly  other disabilities involving loco motor, neurological, visual  and hearing deficit have also been quantified. Unfortunately  the maxillofacial region has not been adequately addressed  in any of these quantification charts.   Quantification of the maxillofacial region is unique on  account of the fact that there are two criteria to be evaluated—  Disability and Deformity. While disability is more readily cal-  culated, deformity is highly subjective and therefore any award  for the latter is bound to be arbitrary. However it is not possible  to ignore the importance of deformity to the face, and an attempt  is made to establish a broad parameter in which it can be  assessed.   Quantification of orthopedic disability is well established  and has been in use for social benefits, rehabilitation, assis-  tance and percentage reservations in labour market placement  of disabled people. It has also been in use for legal and insur-  ance compensations due to accidents, interpersonal violence  and occupational diseases. The Phulhems profile by the  Canadian Army was established as early as 1943. The  McBrides criteria was the established reference in India till  1980. It did cover some aspects of the maxillofacial region  and was generally accepted for dental injuries and dental  loss. The McBrides criteria (1955) was replaced in India by  the “Manual for Doctors to Evaluate Permanent Physical  Impairment” (1981). Unfortunately the impairment and dis-  ability of the face is covered rather incomprehensively and  inadequately, relegating the whole area of the face to one half  of a chapter, with hardly 30 points being allocated to the  face. Not one maxillofacial surgeon sat on the expert com-  mittee of 45 advisors. In the realm of physical rehabilitation  and orthopedics, numerous references are available. Kessler  (1970) covered various aspects of upper and lower extremity  disabilities. The American Academy of Orthopedic Surgeons  Manual (1966) discusses the concept of permanent impair-    ment through a series of questions that reveal the perma-  nency of the deficit. The Govt. of India notification (1986)  covers visual disabilities, locomotor disabilities and hearing  and speech disabilities. It recommends that Kessler’s for-  mula can be taken as a general guideline.   Significantly the only other Indian guideline for  Maxillofacial region comes through a Government of  Tamilnadu notification (1974) where complete facial disfig-  urement is dealt with. It simply awards a 50% for total facial  disfigurement. No break up figures is given for type or sever-  ity of disfigurement.   The American Association of Oral and maxillofacial  Surgeons and American Medical Association have given  guidelines for assessment of maxillofacial injuries and dis-  abilities. They however need modification to suit our popula-  tion and needs.   The authors have depended on two major sources while  making this evaluation.    1. Objective Evaluation of Impairment and Ability in  Locomotor Handicapped by Sabapathyvinayagam  Ramar. An excellent reference book on Physical Medicine  and Rehabilitation.   2. Guidelines to the Evaluation of Impairment of The Oral  and Maxillofacial Region—issued by the American  Association of Oral and Maxillofacial Region.    The authors have modified the guidelines of the above  sources to arrive at the recommendations.   The general aim of the exercise was to evolve quantifica-  tion criteria for disabilities and deformities of the  Maxillofacial region taking into account the special features  of the problems encountered in India. It also endeavours to  simplify the percentages awarded by eliminating complex  variables. The evaluation adopts a position of awarding a  100% to the face to be divided between deformity (50%)  and disability (50%). It does not try to evaluate facial  impairment as a part of the total body as it would signifi-  cantly reduce the quantum of impairment and thus  defeat the purpose of this exercise. Consider a situation  where 100% has to be divided between cardiovascular, ali-  mentary, central nervous and locomotor systems in addition  to sexual dysfunction, liver dysfunction, renal, endocrine and  metabolic dysfunctions. Further distribution amongst visual,  hearing, etc. will certainly minimize any help of giving value  to the face.   The evaluation has also eliminated the need to go into  variables like age, sex and occupation, which will modify the  award percentages. These will rest within the realm of the  government agencies, judiciary or insurance agents.   The criteria formulated shall simply make a statement of  disability/deformity based on standards established within  the purview of the 100% for the face—equally divided    ¢ Impairment: is defined as any loss (or) abnormality of  psychological, physiological (or) anatomical structure  (or) function.   ¢ Disability: WHO defines disability in the context of  health experience as any restriction or lack (resulting  from an impairment) of ability to perform an activity in  the manner (or) within the range considered normal for a  human being.   e Deformity: facial disfigurement involving soft and hard  tissues arising from multiple genetic factors, environment  influences, acquired defects, neoplastic processes and  trauma.    Recommended Quantification for the Dento-facial Region  Areas of Deformity Evaluation—Hard Tissues:    Anteriors Deformity/Disability  All anteriors (upper and lower) : 25%  Between 8 and 11 : 20%  Between 4 and 7 > 15%  Between 2 and 3 10%  One tooth : 05%    Though these are disabilities and deformities that can be  replaced, it deserves the above percentile as the strength and  function of false teeth are not considered equal to natural  teeth. Orthopedic deformities are evaluated even if prosthe-  sis is given.    All posteriors (16) > 25%  Between 10 and 14 : 20%  Between 6 and 9 > 15%  Between 2 and 5 : 10%  Occlusal discrepancy : 10-20%  One tooth : 05%    Loss of teeth due to progressive dental pathology (e.g.  Periodontitis, caries) are not considered. The dental sur-  geon will have to make an assessment based on the condition  of remaining teeth or preexisting records.    Significant loss of bone causing  Deformity/Disability : 10-25%  Small bony fragment 15%   This is an incomplete quantification and will have to be  assessed by the surgeon on the basis of the degree of disabil-  ity/deformity caused by the malunion.    Subjective evaluation based on:  Bony orbit : 5-10%  Soft tissue e.g.) etropian, scar etc  Composite deformities including  Telecanthus etc : 15-25%    Ophthalmic : 8%  Maxillary : 8%  Mandibular : 8%  Tongue : 10%   Impairment rate for interincisor distance of 3cm : 10%  Impairment rate for interincisor distance of 2cm : 20%  Impairment rate for interincisor distance of 1 cm : 30%  Impairment rate for interincisor distance of 0cm_ : 50%   ¢ Class 3—(10-15%) Absence of normal anatomical area  of face. E.g. Loss of eye or part of nose. Visual or hearing  loss will have to be separately evaluated.   e Class 4—(15-35%) Impairment of whole person. Facial  disfigurement is so severe that it precludes social  acceptance.    This criteria appears logical and it significantly simplifies  an otherwise complex quantification of facial disfigurement.  However we would encourage its use with the other men-  tioned parameters. The multiple percentages can be resolved  with the Kessler’s formula.    Another formula has also been used by Ramar as per the  B(90-A)    being the higher value and B being the lower value.  The formula can be used in a few mock situations.    1. X has an injury resulting in the fracture of the mandible  and loss of four incisors. He also develops a pareisis of  the marginal mandibular nerve following surgery. His  total percentile may be calculated thus: A = 15% and B =   2. Y has an injury resulting in the fracture of both condyles  causing subsequent total bony ankylosis. He also has a  large scar with keloid on his right cheek. His percentage    would have been 70. Please note that the value adjusts  itself as the percentiles go up.   Quantifying all kinds of disabilities/deformities is an enor-  mous task. This paper attempts to deal with only those dis-  abilities resulting from accidents. Congenital disabilities/  deformities such as those found in cleft—craniofacial  anomalies will require a more extensive analysis. Similarly  disabilities and deformities caused by aggressive tumours  and cancers of the head and neck comprise a wide range of    problems, which are not necessarily regional. Cancer in par-  ticular may have numerous associated problems ranging  from donor site morbidity to psychological impact affecting  quality of life and mental depression.   Dental injuries and their resultant disability/deformity are  closely linked to aesthetics and mastication. For the purpose  of awarding percentiles, the anterior teeth were considered  for aesthetics and the posterior teeth for masticatory func-  tion. The awards are arbitrary and based on the relative dys-  function caused by the absence of teeth in the masticatory  apparatus. The American Association of Oral and  Maxillofacial Surgery (AAOMS) guidelines award percent-  ages for the complete masticatory apparatus. It awards 24%  for a person who is restricted to liquid diet (40-60% if tube  feeding is necessary) and 5—19% if person is restricted to  semisolids (includes those with ability to wear dentures). We  have taken the liberty of awarding points for individual teeth.  However if the whole masticatory apparatus is to be evalu-  ated, one may separately evaluate absence of teeth, occlusal  disharmony, TMJ movement (craniomandibular articula-  tion), muscle power etc and arrive at a figure by using the   This appears as a reasonable formula, which accounts for  individual disabilities within the framework of the mastica-  tory apparatus.   Further the AAOMS guidelines classifies the percen-  tiles into two categories (1) Percentage of normal. (2)  Percentage impairment of whole person. The dichotomy  does not seem reasonable and is likely to cause further  confusion. Finer details such as lateral excursion etc  which, have been dealt with in the AAOMS guidelines  have been ignored.   Similarly the concept of deformity and disfigurement has  been dealt with differently in the AAOMS and the AMA  guidelines. The matter of disfigurement is complicated by  issues such as personality crisis and the impact of social  acceptance. As suggested earlier this criteria can be incorpo-  rated into Kessler’s formula, thus resolving the issue of mul-  tiple disabilities and deformities.   Finally the question of who can give a disability certifi-  cate. The Indian sources are silent in the matter of maxillofa-  cial injuries. However the law in many American states  clearly provides for the role of a Board qualified Oral  Surgeon or maxillofacial Surgeon to issue disability certifi-  cation for the maxillofacial region.   Contrary to general perception, it is not necessary that  these criteria need to be made by statutory bodies. General  usage can give legal legitimacy. It would of course be in the  best interest of the Surgeon, patient and the public if these  suggestions can be scrutinized, amended and enlarged to  accommodate a larger spectrum of disabilities and  deformities.    A.2.1.2 Duties of Witness  Failure to appear in court without valid reasons after warrant  has been issued can invite contempt of court.   Exaggeration or false statements given under oath is not  only unethical, but can invite punishment under sec. 181,  Sec. 193.    1. Bernhard Wolf Weinberger. Pierre Fauchard, Surgeon-dentist: a  brief account of the beginning of modern dentistry, the first dental  textbook, and professional life two hundred years ago. 1941.   2. Moore W. The knife man. Transworld; 2010. pp. 223-4. ISBN 978-  1409044628. Retrieved 8 Mar 2012.   6. Amin M, Ahmed B. Dental education in Pakistan: current trends  and practice. J Coll Physicians Surg Pak. 2010;20(8):497-8.   7. Mawatha NK. Prospectus, MD oral and maxillofacial surgery and  board certification. Postgraduate Institute of Medicine, University  of Colombo. 2011.    . Zheng J, Fang B, Zhang S, Yang C, Shen G, Qiu W, et al. Oral    and maxillofacial surgery in China: past, present and future. Open J  Stomatol. 2013;03:354-8.    Countries. J Dent Educ. 2002;66(12):1374—80.  EACMEFS. White book. Russia. 1st ed. 2017. http://beta.jointogeth-  ergroup.com/Society/members/whitebook/export.asp?wb=3 |    gery across the globe — a mini review. J Maxillofac Oral Surg.  2017;16(3):269-76.    . http://www.thefreedictionary.com/informed+consent  . Faden RR, Beauchamp TL. A history and theory of informed con-    . Faden RR, Beauchamp TL. A history and theory of informed con-    . Gasparini G, Boniello R, Moro A, Di Nardo F, Pelo S. Orthognathic    surgery: a new preoperative informed consent model. J Craniofac  Surg. 2009;20(1):90-2.    . http://www.surgery.org/press/news-release.php?iid=125  . Paul G. Medical law for the dental surgeon. Jaypee Publishers;    Open Access This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.  org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropri-  ate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.   The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in  a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.   We have all been too quick to make up our minds and too  slow to change them. In Oral and Maxillofacial Surgery, our  opinions are slaves to our prior experience. Ignorant confi-  dence is what defined early Surgery as there was a distinct  lack of interest in proving and promoting what was effective.  The “God complex” among early Surgeons meant that what  they thought was true did not need scientific evidence. It is  only in more recent times that Surgical practice has embraced  evidence to guard against rumour, bias, misconceptions and  misunderstandings. Indeed, just in the last few decades we  have witnessed the gradual evolution of Surgery from  eminence-based practice, the idea that senior experienced  Surgeons held all the knowledge, to evidence-based practice,  where fair tests are employed to compare one treatment  against the other in order to find what works best. History  has taught us that clinical research leads to reforms in the  practice of Surgery while basic research leads to revolutions  in Medicine.   Like in most other scientific disciplines, Surgical research  is used to confirm facts, reaffirm the results of previous work,  solve existing problems and ultimately develop new ideas of  practical value. If you can understand more, you can make  better decisions rather than blind guesses which is the hall-  mark of successful clinical practice. Judgements, predictions  and plans are based on the latest available information and  should be constantly updated in the light of new information  derived from good research. The late British Economist John  Maynard Keynes once said “when the facts change, I change  my mind”. So too, a good Surgeon must be open to new ideas  and techniques which are essential to the progress and evolu-  tion of each surgical specialty, as change is only possible  when key opinion leaders lead the charge.    © The Association of Oral and Maxillofacial Surgeons of India 2021    Essentially, the greatest discoveries in Surgery are those  that force us to rethink our beliefs about human disorders  and our role in managing it. Research builds our core knowl-  edge, and the most useful knowledge is one that changes the  behaviour and practice of Surgeons. The simple idea of  washing your hands before handling patients met with  immense resistance from the established medical community  in the nineteenth century until the scientific evidence sup-  porting microbial infection became too overwhelming to  ignore. Knowledge increases your ability to predict the out-  comes, and the knowledge of bacterial infections was one of  the greatest breakthroughs in modern medicine that signifi-  cantly reduced the mortality and morbidity of even the sim-  plest of surgical procedures. Research has been pivotal to the  success of surgery over the last two centuries and will con-  tinue to be an integral part of all future progress, especially  in the rapidly expanding field of Oral and Maxillofacial  Surgery.   Progress doesn’t occur in a vacuum; it almost always  builds on existing ideas with a series of incremental improve-  ments. That is why most research is used to develop further  knowledge on a topic by reaffirming the results, theories and  problems of past work in the field. Occasionally, when trying  to solve an existing problem, research may lead to the dis-  covery of new problems, ideas and theories which makes the  science of Surgery a dynamic process of knowledge acquisi-  tion that has no endpoint.    The word Science comes from the Latin “scienta” which  means knowledge or skill. Science is about new ideas and  testing these in the most transparent way. What launched the  Scientific revolution was the realization that we do not have  the answers to their most important questions. To find the  answers, experiments are what people devised when they  weren’t sure of the truth. Ignorance is the starting point of all    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1-15-1346-6_45    science, and curiosity about the world around us is what  drives science. The more that is unknown, the greater the  opportunity to discover, and that is how research has become  an essential tool of discovery.   The word Research is derived from an old French term  referring to seeking or searching. Research is all about the  ability to test, reproduce, quantify and falsify an idea before  it can be fully accepted as scientific fact. In research we learn  more from the unexpected results than from those we antici-  pate. Understanding the research process helps generate new  research questions. The trick is to ensure the right methods  are used to answer the right questions. For example, when  we are seeking verification, we must ask ourselves “Did I  build the system right?”, while if we want to validate some-  thing, we then ask “Did I build the right system?”.   Scientific research is a systematic way of explaining  things by collecting evidence which make practical applica-  tions possible. The goal of research is not only to yield new  knowledge but also to make us better understand existing  issues or topics. There are three main forms of Research;  Exploratory research helps to identify a problem, while  Constructive research proposes solutions to the problem. The  third is Empirical research which tests the feasibility of the  solution using either qualitative or quantitative methods.  Qualitative research collects data in the form of words,  images and video which is largely confined to the social sci-  ences but may also have applications in Surgical techniques.  The difference between quantitative (numbers) and qualita-  tive (descriptions) research is well summarized by the  famous scientist, Albert Einstein, who once said that “Not  everything that matters can be measured, and not everything  that can be measured matters”. The world cannot be under-  stood without numbers, and equally, it cannot be understood  with numbers alone.   In Surgery, quantitative research is most often used to  establish the existence of causal relationships between vari-  ables by collecting and analysing numerical data. By relying  on random sampling, the quantitative research method allows  for experimental, correlational and descriptive (i.e. survey)  results that are easy to summarize, compare and generalize  using statistics to determine the relationship between vari-  ables. For example, if the research question is about best  mandibular reconstruction following tumour resection, the  patients may be randomly assigned to different groups, each  representing a different mode of reconstruction. If this is not  feasible, the researcher may collect data related to the  patient’s demographics and situational characteristics to sta-  tistically control for their influence on the degree of morbid-  ity following their particular mandibular reconstruction.  Often the intent of the surgical research is to generalize from  the study participants to a larger population which will  require the researcher to employ probability sampling to  select the study participants.    Scientific research follows a structured process. Successful  research is only possible when asking the right questions,  engaging in the right observations, running the right experi-  ments and networking with the right people to elicit ideas  and feedback. The core principle of science and research are  precision and transparency—being clear about your methods  and honest with your results. Transparency is what gives sci-  ence credibility. World-changing ideas and technology were  built from a protracted process of trial and error. Experiments  are designed to show what does work and what doesn’t. It is  by testing that we gain access to the feedback that drives  progress. Formal research has a well-established pathway  that follows the basic steps set out below.    Many people simply watch the world around them (on auto-  pilot). Few people observe. An astute observer will see the  problem only when they’re not vested in the way things have  been. Their ability to imagine how things should be is what  drives change and progress. The hardest part of solving a  problem is seeing it, and many surgeons blindly follow pro-  cedures that do more harm than good for the patient because  they have failed to question the surgical technique they have  been taught. In surgery, very few surgeons have ever asked  the pivotal question—“Is there a better way?” Curiosity and  an open mind is what drives progress, and unfortunately,  most surgeons have achieved their chosen profession by not  rocking the boat and adhering to conventional practices.   Many of the things we accept as objective truths are them-  selves assumptions based on uncertainty, even in the world of  Surgery. No surgical concept or technique has an absolute and  permanent value. Time, experience and better experimental  tools give rise to new ideas that supplant the old ideas. In  other words, all existing surgical ideas and techniques are  sooner or later supplanted by new ideas and techniques which  means surgery is a never ending marvel of evolution.    Before embarking on any kind of research, the first step is  to look for any idea or technique that has not been adequately  explained or supported by evidence. When looking to a topic  or issue as a potential subject for research, the hierarchy of  deliberation begins with (1) “Where is the evidence?’, (2)  “How sound is the evidence?” and (3) “Has the evidence  been properly interpreted?”. Once you have selected the  appropriate subject or topic you would like to explore, the  next step is to find out what the literature has to say and look  for gaps in the existing knowledge.    All the world’s information is now at our fingertips, and to  access scientific publications is a matter of a few keystrokes.  Search engines like Google Scholar and PubMed have  opened up a whole new digital world of scientific literature  that even the largest University libraries could never hope to  subscribe to. Access to the world’s scientific literature has  never been simpler than it is today, and subscriptions to  University libraries also allow students digital access to a  wide range of local and international journals.   Once the research topic has been selected, a thorough  review of the literature is required to establish what is already  known. It is best to begin with the most recent peer-reviewed  articles on the topic which will often summarize the existing  body of knowledge. Meta-analysis papers, especially those  that follow the PRISMA guidelines, are becoming more  common, and these papers can form the foundation of your  research topic. Good journal papers will commonly highlight  the gaps in our knowledge, the weakness in the current evi-  dence available, and what further research is required that  will conveniently point you in the right direction.    Once you have gathered all the pertinent information from the  literature review, the next step is to crystalize in your own mind  why you are embarking on this research. The flaws or holes in  previous research are identified so that the gaps in the literature  will provide justification for the new research being proposed.  Look for clues in the literature where there may be a deficiency  in the evidence surrounding published statements, particularly  those that make generalizations that are not adequately backed  by evidence. Indeed, many Cochrane reviews have consistently  concluded that the vast majority of clinical papers fail to pro-  vide the level of evidence required to make any firm conclu-  sions. The aim or purpose of the research is pivotal to the whole  project as it dictates the methodology required to adequately  address the aims. It is also the main driver in funding applica-  tions and recruiting study participants.    Science grows with every new piece of evidence with the  hypothesis as the compass that directs the inquiries. Scientific  theories have to make testable predictions that can be vali-  dated in experiments. Science is not just about confirmation;  it is also about falsification. If a theory cannot be tested, then  it’s logically impossible to ever falsify it. Karl Popper said  “if it is not falsifiable, it’s not scientific”. If a theory cannot  be tested with experiments, then it falls in the realm of reli-  gion or philosophy or pure speculation. Questions that gen-  erate the greatest emotional response are a great indicator of  challenging the way things are.   The gap in the literature creates a research question which  is otherwise referred to as the Hypothesis. The Hypothesis is  a prediction which is set out as a statement that defines the  relationship between two or more variables. In research, it is  the hypothesis that is being tested as to whether it is true or  false. If the hypothesis turns out to be consistent with the  observations, then it is said to be supported rather than  proven as it is still subject to further scrutiny. But if it is  rejected, then support is claimed for an alternative hypothe-  sis. The Null hypothesis is when there is no relationship  between the variables being investigated.    In the hypothesis statement, there will be two or more vari-  ables that will be the focus of the study. The study is designed  to establish the relationship between the variables. However,  before commencing the study, the variables must be clearly  defined so that there is no doubt as to what each variable  represents. Without clear definitions of the variables, studies  cannot be repeated and hence impossible to validate.    What isn’t measured can’t be managed. Without data, we  cannot make informed decisions. We gather data to collect  information that becomes knowledge which is finally dis-  played as wisdom. Data has to be collected, processed and  analysed for it to become information which can be used to  make better decisions. Ultimately, the answer is only as good  as the quality of the data fed into it.   Apart from field studies such as surveys and clinical  audits, OMF Surgeons also conduct experiments that involve  laboratory controlled conditions, often by recruiting the  resources of other medical specialities such as pathology,  microbiology, radiology, biochemistry, pharmacology and  haematology. Data collection is easiest when data points can  be quantified or represented with numerical figures. Even    descriptive surveys can be quantified provided the responses  can be listed on a sliding scale ranging from good to bad,  high to low or positive to negative. A typical example is the  visual analogue scale used by OMF Surgery researchers to  quantify pain scales, chewing ability and quality of life out-  comes before and after jaw surgery.   In Medicine, randomized trials where the patients and  experimenters are blinded are least vulnerable to bias than  observational studies, which are most prone to bias.  Unfortunately, randomized trials are more expensive than  observational studies and require a lot more manpower and  resources to properly execute. In surgery, we most com-  monly rely on observational studies as the best evidence we  have to go on for two reasons. Firstly, control groups with  which to compare treatment outcomes, unlike a placebo  sugar drug, are rare as it is ethically impossible to undertake  sham operations. And secondly, it is practically impossible to  blind surgeons and patients when it comes to evaluating sur-  gical procedures. Evidence in the field of Oral and  Maxillofacial Surgery therefore relies largely on observa-  tional studies derived from surveys and clinical audits of  case series.    Data science is about understanding the world by spotting  patterns and predicting how one variable will affect  another. While our instincts may give us a reasonable sense  of how the world works, we need data to sharpen the pic-  ture as we can be easily blinded by our own experiences  and prejudices.   Data shows us there is more to OMF Surgery than we  think we see. Good data science can often demonstrate coun-  terintuitive results—what you least expected to see. Selection  biases are distortions of the results introduced either by the  data collecting tools or by the method of data accumulation.   Statistics is a valuable tool that helps determine whether  the results you have found are likely to be due to a chance  rather than a true finding. Make sure the data is collected on  an Excel spreadsheet, and work out what level of confidence  you will accept as statistically significant which, in clinical  research, is often the 95% confidence level (i.e. P value  <0.05). In statistics, the smaller the sample, the lower the  likelihood that it would mirror the broader population. Large  samples yield more precise results, while small samples are  more susceptible to extreme results. As sample sizes get  larger, the statistical calculations from that sample get more  precise. Small differences (1%) between two populations  being measured require bigger sample numbers than large  differences (25%) for the true value to emerge. This is called  the power calculation which is an important measure to con-    sider before embarking on any study. Statistics is a complex  affair and beyond the scope of this chapter, so the services of  an expert statistician may well be useful when it comes to  crunching the data.    Information is interpreted by different people in different  ways. People can look at the same set of facts and dis-  agree. Data can be manipulated to support any argument.  You don’t always need a ton of data to find important  insights. What you need is the right data. Numbers can be  seductive. We can grow fixated with them, and in doing  so, we can lose sight of more important considerations.  When looking at data, it is not the raw crunching power  you have that matters most, but what you do with it that is  most important. Behind every statistic there is a certain  set of assumptions and prejudices. Minds crave certainty,  and when they don’t find it, they impose it so we must  keep an open mind when the data does not yield the results  we expected to see.    Your judgement call about how the results support your  hypothesis is essential to your conclusions. If the data does  not support your hypothesis, then it is essential to state an  alternate hypothesis that fits with what has been observed.  The scientific method is tailor-made for cherry picking  because of its hypotheses and caveats and refusal to embrace  certainty. Even in Science, certainty still relies on the  assumptions, interpretations and theories of researchers  based on what they see. Nothing is definite, for doubt is an  essential operating principle of science. This means that  doubt still has a place in all scientific proofs, so that all evi-  dence is provisional and not final. In other words, what you  have ascertained in your research is not definite proof but  rather tacit support for an idea.    The conclusion is a summary of the entire experiment or  study that simply states the outcomes observed which must  be clear, concise and to the point. Any ambiguity should be  highlighted and recommendations made as to how future  studies should be conducted to minimize the uncertainty. It  may simply be a numbers game where more patients are  required, or additional groups such as control patients which  may provide a clearer outcome. For example, the effective-    ness of Botox in Myofascial Pain (TMD) can never be prop-  erly evaluated if there are no control groups (i.e. that have  normal saline injected) with which to compare.   The conclusion is the most sought after piece of informa-  tion that others will first look at when reviewing your  research. Although it sounds rather obvious, the conclusion(s)  must be supported by the data; otherwise, the research makes  no sense. The onus is on the researcher to make sure the con-  clusions also fulfil the goals and aims of the study.  Recommendations based on the conclusions are essential in  providing a practical guide to surgical practice. Research is  what drives clinical advances in Surgery, and the change in  behaviour of Surgeons can only be achieved with evidence.    Research is useless if it is not shared with the outside world.  All humanity is now connected by digital technology which  has rendered distance, time and costs irrelevant to the distri-  bution and exchange of ideas. The digital world has made  recording, storage and dissemination of information, research  and ideas virtually free with costless reproduction and  instantaneous global distribution. Reporting and publishing  research findings is described in detail in Sect. 5.    Cultures that fail to encourage questioning also fail to come  up with new ideas. Great institutions should teach us how to  ask hard questions and where to look for answers. Knowing  all the answers does not distinguish someone’s intelligence—  rather, the ability to ask the right questions and linking the  unconnected is the mark of a true genius. Generally, it is con-  sidered a weakness and a sign of vulnerability for clinicians  to appear unsure. Confidence in medicine is valued over  uncertainty, but science is all about uncertainty which drives  progress. If we knew it all, there would not be a need for  research.   Nothing is as powerful as an idea whose time has come.  New ideas are what drive behavioural change and innova-  tion. A new behaviour needs social approval before others  are likely to pick up the habit as their own. Only the curious,  who are open to learning, have a much greater chance of  creating a truly novel solution. Unfortunately, originality is  not always embraced by the surgical profession who are gen-  erally conservative by nature.   It is much easier for Surgeons to accept familiar ideas  than totally original ones because if the ideas are too origi-  nal, then it may be too hard for the Surgeon to accept or    understand. The goal is to push the envelope, not to tear the  envelope. Radical ideas are best presented in a way that is  less shocking and more appealing to mainstream surgical  practice by planting the seeds of a simple idea before reveal-  ing the larger idea. If you want your ideas to be accepted by  your peers, make your ideas more appealing by connecting it  with other ideas that are already understood by your col-  leagues. Other constraints related to research involve ethics,  funding and bias which are discussed below.    There has been a push in recent years by institutions and  clinical journals to have all animal and human research activ-  ities sanctioned by appropriate ethics review boards or pan-  els attached to hospitals or Universities. Without ethics  approval or clearance, it may be impossible to conduct even  the simplest of clinical studies, including basic surveys.  Some Journals now request a copy of the ethics clearance  letter before the paper can even be put out to review.   Unlike pharmaceutical research, the level of evidence in  clinical surgery is hampered by the fact that control subjects  are often missing because you cannot ethically perform sham  operations in humans. Therefore, when designing surgical  experiments, consider whether animal, laboratory or cadaver  studies may be useful instead. Otherwise, you are limited to  clinical audits which provide useful information which may  not be scientifically valid. For example, a hospital which  boasts 100% survival of its patients achieves this by turning  away the sickest patients. Or a hospital which has the worst  outcomes may well be a tertiary referral centre that only  treats the most complex of cases that other hospitals turn  away. So, while clinical audits provide a snapshot of the  Hospital Unit’s activities, it tells us very little else as far as  science, progress and innovation is concerned.   We must be suspicious of therapeutic claims that have not  been properly tested. Equally, we must be even more suspi-  cious of research results that cannot be replicated. Many  people are driven by a deep human desire for recognition and  affirmation of work well done. Sometimes it is possible to  build an academic career by sounding clever, rather than  being clever. Most academics chase large numbers of trivial  publications instead of investing their energies in new fron-  tiers. In other words, why search for something new when  you can collect rents on everything that has already been  done. Sadly, there are small numbers of academics and  researchers who have built their careers on falsification and  plagiarism. The desire for recognition and the need for pro-  motion when combined with the pressure to publish can tip  some academics, clinicians and scientists towards fraudulent  activities where data is made up and text is plagiarized in    Scientists have an innate desire to innovate, share, collaborate  and be recognized for it regardless of the financial incentives.  Hence, good research requires funding from external sources.  Unfortunately, the spirit of open scientific enquiry can some-  times be hijacked by the combination of self-interest and  money, especially when industry offer to bankroll the study.  Industry rely on profitable enterprises which grow share-  holder value. Scientific support behind a product is perhaps  the ultimate value-adding marketing tool, so industry are  always looking out for research that shows positive outcomes  related to their products. Furthermore, industry never leave  anything to chance so they want control of scientific research  through financial rewards to various research institutions. By  directly funding research, industry have control over what is  published (i.e. the positive results) and what stays buried in a  locked cupboard (i.e. the negative results).   Therefore, the most respectable research is that which is  funded by government or not-for-profit organizations such as  Medical Societies and disease interest groups like the Heart  Foundation or the Cancer Council and so on. Funding from  non-industry groups are much more competitive as there is  always a limited amount of money available for research so  applications must be of high quality. Furthermore, the non-  industry funding bodies give free reign to the scientists on  how the data is used and published. Industry funding, on the  other hand, have simpler applications but more control of the  data which remains their property. Most importantly, indus-  try insist on the final veto on whether or not the results are  published.    Confirmation bias is one of the shortcomings of science  because the human mind is bad at seeing things it did not  expect to see and a bit too eager to see what it expected to  see. It is basically seeing what you want to see and ignoring  everything else. In essence, confirmation bias is when you  filter reality through biases by eagerly accepting evidence  that confirms what you believe and ignoring evidence that  refutes or challenges what you believe. Once we adopt a par-  ticular hypothesis or interpretation, we find it difficult to see  things any other way. People will accept any explanation as  long as it fits with their own understanding of the facts.    Cognitive dissonance is another impediment to scientific  progress that affects many people. It is simply a feeling of  discomfort that people experience when presented with infor-  mation that is inconsistent with their beliefs. When we are  confronted with evidence that challenges our deeply held  beliefs, we are more likely to reframe the evidence than we  are to alter our beliefs. In most cases, instead of acknowledg-  ing an error in judgement, people tend to reformulate their  views in a way that justifies their old opinions. We simply  invent new reasons, new justifications, or new explanations or  ignore it altogether. Some people go to absurd lengths to jus-  tify their beliefs or judgement even when confronted with  clear contrary evidence. The more committed we are to a cer-  tain opinion, the less likely we are to relinquish it, even when  confronted with massive or overwhelming contradictory evi-  dence. As an example, the introduction of microvascular  venous couplers in microsurgery was developed by those who  could see the obvious benefits of speed and patency of the  anastomosis, and yet was resisted by those who felt the skill  of micro-suturing tiny veins would be lost, regardless of the  benefits of reduced thrombosis and improved flap survival.    Research cannot thrive without publishing. All research proj-  ects are conceived with publication as the end game. The  excessively competitive field of research creates a tendency  to rush to conclusions and publish results that have not been  properly validated. Valid conclusions can only be drawn  from reproducible data sets because results that initially look  promising aren’t always repeatable. It is little wonder that  remarkably few published breakthroughs have ever led to  any useful treatments.   There are numerous media that researchers can use to  propagate their experimental findings which are discussed  below.    Digital technology has not only transformed but has revolu-  tionized the way we live. The merger of the personal com-  puter and the Internet allowed networking to blossom on a  massive scale, and so surgeons and scientist are not wholly  reliant on print media to propagate their ideas. Websites like  ResearchGate encourage scientists and clinicians to upload  their research, both published and unpublished, onto a digital  platform for all to see and to foster collaboration between  research groups across the world.    Digital media platforms like YouTube are fast becoming a  quick, easy and virtually cost-free way of publishing your  novel ideas and surgical techniques on the Internet for all to  see. More and more Surgeons are bypassing the heavily for-  tified realm of print media for the highly accessible digital  media which not only offers a global audience but also facili-  tates immediate upload of content with virtually no delay.  The disadvantage is of course the lack of scrutiny which sug-  gests the content has not been vetted by experts. Hence, the  scientific value of the video post is virtually zero. While you  may have a wide audience, it may not necessarily be the peo-  ple you want to impress.    Glossy magazines that specifically target general medical/  dental practitioners are supported by lots of industry  advertising which is interspersed with clinical articles that  have not been peer-reviewed, but rather submitted on the  invitation of the magazine editor. The articles, which  often have more clinical pictures than text, are written by  clinicians and academics as a general interest piece that  provides the reader with an update of what is current clin-  ical practice that is aimed at the non-specialist practicing  clinician. Authors are generally paid for their contribu-  tions. These articles are of little value to the specialist  trainee or clinician wanting to find out more about their  own specialty.    Textbooks contain information that is current practice and  accepted by the profession. Unfortunately, by the time a  textbook is commissioned, written, published and finally  released, the information is often about 2 years out of date.  Therefore, the strength of textbooks is in the basic princi-  ple of surgical practice, and the weakness lies in the dis-  tinct lack of new information. Digital technology is  gradually changing the need for printed textbooks as stu-  dents are gravitating to knowledge that is presented in dis-  crete digital packages with hyperlinks that cross-reference  important concepts similar to “Wikipedia”. While univer-  sity and hospital libraries still purchase textbooks for stu-  dent consumption, today’s students are finding the expense  of textbooks prohibitive and so seek other means of access-  ing surgical information and knowledge through the  Internet, which is often up to date as long as they know  what to look for and are able to critically evaluate the cred-  ibility of the information source.    There are over | million academic papers published every  year in over 24,000 academic journals where gaps in our  knowledge are discussed and new experiments are conducted  that might resolve these gaps. Unfortunately, published sci-  entific papers tend to be biased towards reporting positive  results. Negative results do not make headlines so they are  rarely published. Publication in a journal is not a mark of  truth but merely that the research has passed a certain stan-  dard that warrants entering the formal literature and further  discussion.   Scientific journals sell scholarship back to the same uni-  versities whose scientists had produced, written, peer  reviewed and edited largely for free. Hence the cost of pro-  ducing scientific journals is kept as low as possible in order  to facilitate as wide a distribution as possible. Unlike maga-  zines, peer-reviewed journals with few exceptions keep  industry advertising to a minimum as they are supposed to be  impartial to avoid conflict of interest when reporting studies  that may conflict with the interests of a big advertiser.   Peer-reviewed journals are the platform we use to  announce new discoveries, to comment on or criticize the  discovery of others and to synthesize and seek to build con-  sensus about what is known. In Oral and Maxillofacial  Surgery, case reports and technical notes account for about  one-third of journal publications, while less than one in ten  are randomized control (Level 2 evidence) or non-randomized  control (Level 3 evidence) studies (Table 45.2). Because of  the difficulty in performing high-level randomized control  trials in surgery, Surgeons are more accepting of lower-level  evidence which is based on observation. Indeed, it is unlikely  to extract any high-level evidence research from surgical  departments who rely on surgical trainees for their research  output.    Level 1: Randomized control trials (RCT)  High-quality, properly powered and conducted studies with reduced  bias when double blinded and multicentred  Level 2: Cohort clinical studies  Prospective, comparative clinical study without randomization  Level 3: Case-controlled studies  Retrospective clinical study  Level 4: Case series studies  Cross-sectional study (clinical audit) with or without intervention  Level 5: Case-based reasoning  Includes case reports, expert opinions and bench research  Note: The strength of systematic reviews and meta-analysis depends on    the evidence levels of the papers being reviewed. If all the papers are  Level 3 evidence, the systematic review will also be Level 3 evidence    Table 45.3 Factors to consider in the design of a clinical study    1. Where is the study being conducted? (field, hospital, clinic,  laboratory, etc.)   6. Results set out in clearly labelled tables, graphs, figures, photos,  diagrams   refute results  . The most recent references that adequately support discussion  9. Conclusion supported by the results of the study   4. Plagiarism and duplication (study previously published  elsewhere under different title)    All journals subscribe to the IMRD layout which means  all submissions must have an Introduction, Methods, Results  and Discussion sections. The introduction builds the case for  why you pursued the line of research and the final sentence is  always the statement of the aim(s) of your study. The Methods  section describes how the study was performed in terms of  setting (e.g. Hospital or Laboratory), subjects (i.e. animals or  humans), recruitment (e.g. inclusion/exclusion criteria), data  collection (e.g. Surveys, measurements), variables being  compared (experimental vs. control) and data analysis (statis-  tics used) (Table 45.3). The Results section simply states the  summary of the outcomes as depicted in the tables and graphs,  while the Discussion critically analyses and compares the  results in light of what has already been previously published  on the topic. The discussion must include references that both  agree and disagree with your findings so that a balanced argu-  ment can be presented which will add weight to the study.    1. | Randomized control studies: | www.consort-statement.org  2. Observational studies: www.strobe-statement.org  3. Systematic reviews: www.prisma-statement.org  4. Case series: www.processguideline.com  5. Case reports: www.scareguideline.com    The final paragraph in the discussion is a summary of the  research results with mention of any practical clinical appli-  cations that may arise from the study.   Authors must keep in mind that originality and a clear  message are essential in getting their papers published in the  highly competitive world of scientific journal publishing  (Table 45.4). The high impact factor journals generally attract  articles with high evidence levels so it is imperative to select  a journal that caters to the subject and evidence levels of your  particular study to avoid rejection and delays in publication of  your paper. Original contributions that add new information  to the existing body of knowledge are more likely to be con-  sidered for publication. However, wild or fanciful ideas are  unlikely to garner support from journal editors who are look-  ing for papers that lend respectability to their journal.   Unlike works of fiction, good scientific communication is  based on clear and concise wording with short titles and  tightly controlled sentences that describe complex ideas in  the simplest language possible. Poor grammar, emotive lan-  guage and long-winded descriptive wording must be avoided  so that the ideas being conveyed are not buried in a convo-  luted tangle of discourse (Table 45.5). When evaluating the  importance and relevance of published articles, surgeons and  scientists look for the facts, not fancy prose.   To improve the acceptability of your paper for publication  in a peer-reviewed journal, there are general guidelines avail-  able online that help you set out your paper in a format that  is recognized and accepted throughout the world (Table 45.6).  By following the guidelines, you improve the chances of  your paper being accepted for publication. For instance, if  you want to submit an observational case cohort study, then  the “STROBE” statement will guide you in how to properly  format your paper. If it is a case report then it is worth check-  ing out the “SCARE” guidelines. Alternatively, if you want  to undertake a systematic review of a topic, the “PRISMA”  statement is essential.    In Surgery there is no greater accomplishment than being the  first to successfully implement a successful treatment that  changes the history of medicine. However, the person with  the first idea is usually not the one recognized by history.  Credit often goes to the person who convinces the world, not  to the one with the original idea, because the credibility of all  new ideas requires convincing evidence. If you make a claim    about something, you provide the evidence, or at least a ref-  erence to the evidence that backs your claim. Research is the  essential tool that builds the evidence which provides a better  understanding of how and why things worked or failed.  Good surgical practice must be based on evidence.   Surgical innovation is a constant work in progress because  any new ideas or techniques are quickly supplanted by an  even better ideas and techniques. Gaps in the literature are  what fuel research, and the journey of discovery is paved  with potholes that need to be filled. To paraphrase the great  scientist Sir Isaac Newton, if you want to see further than  anyone else has seen before, you need to stand on the shoul-  ders of giants. Your voyage of discovery begins once you  have secured your footing on the shoulders of the surgeons  and scientists who have gone before you, so you can see the  path they have built for you to follow.    Dimitroulis G. EDITORIAL — Getting published in peer-reviewed jour-  nals. Int J Oral Maxillofac Surg. 2011;40:1342-5.   Hardicre J. An overview of research ethics and learning from the past.  Br J Nurs. 2014;23:483-6.   Knottnerus JA, Tugwell P. EDITORIAL — Evidence-based medicine:  achievements and prospects. J Clin Epidemiol. 2017;84:1-2.   Lau SL, Samman N. Levels of evidence and journal impact factor in Oral  & Maxillofacial Surgery. Int J Oral Maxillofac Surg. 2007;36:1-5.   Mohan M, Shetty D, Shetty T, Pandyak K. Rising from plagiarising. J  Maxillofac Oral Surg. 2015;14:538—40.   Sollaci LB, Pereira MG. The introduction, methods, results, discus-  sion (IMRAD) structure: a fifty year survey. J Med Libr Assoc.  2004;92:364—-7.    Open Access This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.  org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropri-  ate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.   The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in  a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.   The salivary glands secrete saliva which has lubricating,  immunologic, digestive, and cleansing functions. They are  affected by systemic and local inflammatory conditions,  obstructive pathologies, as well as neoplasms. Most of the  tumors are parenchymal in origin, whereas few could be  interstitial. Majority of tumors affecting major glands are  benign, but those affecting minor salivary glands are more  often than not, malignant. The disorders that involve these  glands can either be acute or chronic inflammatory lesions,  congenital abnormalities, systemic disorders, or benign and  malignant tumors. However the most, common disorders  affecting salivary glands are tumors and infections.    The gland lies in the retromandibular fossa bound medially  by the styloid process and superiorly by external acoustic  meatus and mastoid process, and it touches the medial ptery-  goid muscle and mandibular ramus (Fig. 46.1). A part of the  gland may also cover the TMJ in front of the ear but never  extends beyond the zygomatic arch. The parotid capsule is a  dense, adherent fibrous condensation of deep cervical fascia  which is tough and unyielding. Hence parotid space infec-  tions show minimal swelling but are severely painful.  Incision and drainage is needed early on, without a frank  fluctuant abscess to relieve the pressure within the capsule to    Electronic Supplementary Material The online version of this chap-  ter (https://doi.org/10.1007/978-98 1-15-1346-6_46) contains supple-  mentary material, which is available to authorized users.    N. A. Agni (D4)  Department of Oral and Maxillofacial Surgery, SMBT Institute of  Dental Sciences and Research, Nashik, India    © The Association of Oral and Maxillofacial Surgeons of India 2021    prevent pressure necrosis of the parenchyma. Due to weak-  ness in the capsule covering the deep surface of the gland,  parotid abscess may spread into the lateral pharyngeal space,  if not drained promptly [1]. Benign tumors grow slowly and  hence take a longer time to manifest as external bulges.  Parotid gland has a superficial lobe (80%) and a deep lobe  (20%) connected by an isthmus with the facial nerve passing  between the two lobes.   The facial nerve is related to the parotid gland in a number  of ways [2].    1. (a) Superficial and deep lobes are united above, so that the  gland is essentially folded over the nerve.  (b) An isthmus uniting the two lobes.  (c) Combination of (a) and (b)   2. The gland and nerve can also lie intertwined within super-  ficial and deep lobes; relation will vary according to plane  of section.    The intratemporal and intraparotid facial nerve has varied  pattern of branching which is of immense surgical impor-  tance and might show bifurcation and trifurcation of the main  trunk within the mastoid segment (Fig. 46.2). This intratem-  poral division of the facial nerve is associated with congenital  abnormalities of the pinna or inner ear (Table 46.1).   Parotid duct or the Stensen’s duct crosses the masseter  about a finger breadth below the zygomatic arch. It then  takes a sharp turn medially at the anterior border of the mas-  seter further traversing through the buccal fat pad and buc-  cinator muscle. It then runs obliquely between the buccinator  and oral mucosa to open on the parotid papilla, opposite the  second maxillary molar. The obliquity of the duct in between  the buccinator and mucosa acts like a valve to prevent infla-  tion of the duct while blowing air. The duct lies between the  upper and lower buccal branches of the facial nerve. Its cali-  ber is about 3 mm, but at the point where it penetrates the  buccinator muscle, an isthmus narrows down the duct to  1.2 mm, and at the orifice (ostium), it is 0.5 mm.    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1-15-1346-6_46    Structures traversing the parotid gland from lateral to  medial (superficial to deep) include the facial nerve, retro-  mandibular vein, and external carotid artery. Few parotid  lymph nodes are also present within the gland.   Parasympathetic secretomotor fibers from the inferior  salivary nucleus of the ninth cranial nerve supply the gland.  Nerve fibers pass to the otic ganglion via the tympanic  branch of the glossopharyngeal nerve and the lesser petrosal  nerve. Postganglionic parasympathetic fibers reach the  parotid gland via the auriculotemporal nerve, which lies in  contact with the deep surface of the gland. Postganglionic  sympathetic fibers reach the gland as a plexus of nerves  around the external carotid artery [4].    46.2.1.1 Identification of the Facial Nerve [5, 6]  The facial nerve identification can be done either proximally  or distally. Proximally the main trunk of the nerve is identi-  fied before it enters the gland. Distally it is identified as  branches after the nerve leaves the gland (Table 46.2).  There are four facial nerve pointers at the stylomastoid  foramen. However more techniques have been added later on  by various authors. They are as follows:    1. The cartilaginous pointer of Conley (1978) is created at  its anterior inferior border and is the least reliable one.  The backward pull on the cartilage causes the meatus to  assume the shape of a horn, the curved extremity of which  allegedly points to the position of the facial nerve. The  nerve is located medial and inferior to the pointer  (Fig. 46.3).    2. A short segment of the facial nerve lies in between the  stylomastoid foramen and parotid gland and is an ideal  location to identify it. It can be located in the tympano-  mastoid sulcus which is formed by the edge of the bony  external meatus and anterior face of the mastoid process.  The nerve emerges from the stylomastoid foramen some  3—4 mm deep to the outer edge of the bony external canal.  The tympanomastoid sulcus is filled with fibrofatty lob-  ules that mimic the facial nerve trunk which may lie as  deep as | cm to this landmark.   3. The anterior superior aspect of the posterior belly of the  digastric muscle is inserted just behind the stylomastoid  foramen. The posterior belly of the digastric muscle lies  just inferior to the nerve and is the most reliable landmark  to identify the nerve (Fig. 46.4).   4. The styloid process is a confirmatory landmark. The  facial nerve lies lateral to the styloid process near the sty-  loid base. The posterior auricular artery bleeds frequently  while looking for the facial nerve since it lies below and  just lateral to the nerve, and hence it cannot be relied upon  for identification of the nerve.   5. Borle’s triangle has been recently introduced to locate  the facial nerve trunk. Lines are drawn from the tip of  the mastoid process, running along the superior border  of the posterior belly of digastric muscle and posterior  border of the ramus of the mandible. These two lines  intersect with each other anteriorly, forming the apex of  the triangle (angle a). The base of the triangle is marked  by drawing the third line starting from the tip of the  mastoid process (angle b), running anteriorly till it joins    Table 46.1 Katz-Catalano classification Table 46.2 Facial nerve identification  Type 1 25% Branches are separate Anterograde approach—Direct identification of main trunk at  Type 2 14% Buccal branch fuses with zygomatic branch 1 stylomastoid foramen  Type 3. 44% Major communicating, buccal, and other branches 2 Retrograde approach—Early identification of mandibular branch  Type4 14% Complex branching between all branches over posterior facial vein or other branches along the parotid duct  Type 5 3% More than one major trunk 3 Supravital staining of parotid—gland is stained blue, tumor is    Katz and Catalano [3], 1987 unstained, and facial nerve is gleaming white    Fig. 46.4 Showing relation of the posterior belly of the digastric mus-  cle and main trunk of the facial nerve (muscle pointed by mosquito  forceps)    the second drawn line along the posterior border of the  ramus (angle c). The facial nerve trunk is often found  within this triangle just above the angle b formed by the  first and the third line if gentle and blunt dissection is  carried out at this point. The mean distance of nerve  trunk from the angle b is 12.18 + 2 mm within a range of  9-15 mm [7] [Fig. 46.5—https://www.ncbi.nlm.nih.  gov/pmc/articles/PMC6126203/. doi: https://doi.  org/10.1016/j.jobcr.2018.08.004. (open access)].    Fig. 46.5 Borle’s triangle. Line 1: Started from mastoid process tip  and running along the superior border of posterior belly of the digas-  tric muscle. Line 2: At the posterior border of ramus of the mandible.  Line 3: Starts from the tip of the mastoid process running anteriorly till  it joins the second line. Angle a: Lines 1 and 2 intersect with each other  forming the apex of triangle. Angle b: Is the base of the triangle. Angle  c. Is the angle where third line meets second line    When identification of facial nerve trunk is difficult using  the above said pointers due to distorted anatomy due to the  tumor, a retrograde approach can be used by identifying a  peripheral branch of the nerve and tracing it proximally. The  easiest branch to locate is the marginal mandibular nerve.  Baker et al. have reported that the marginal mandibular nerve  is located 1-2 cm below the inferior border of the mandible.  The marginal mandibular branch can be used to trace the  facial nerve in a retrograde direction by identifying it at the  point of emergence of the retromandibular vein and then car-  rying out a proximal dissection. By working backward along  the nerve, the two divisions, the other branches, and the main  trunk can be found [8].   Figure 46.6 represents the average distance of facial nerve  pointers from the surrounding landmarks (Table 46.3).   Intraoperative facial nerve monitoring using electromyo-  graphic techniques can also be used for identification of the  main branch or the peripheral branches in centripetal or retro-  grade approach. In pediatric population the facial nerve trunk    exits the stylomastoid foramen and is found approximately  1 cm anterior to mastoid process and 1.5 cm posterior to the  ramus of the mandible. The parotid does not extend posterior  to the ramus of the mandible in the newborn infant and conse-  quently covers only the lower distal branches of the nerve [9].    46.2.1.2 Facial Nerve Monitoring  There are two types of facial nerve monitoring:    Facial nerve monitoring is performed with a nerve stimu-  lator which can either be monopolar or bipolar. The monopo-  lar stimulator is more useful for identifying the nerve, while  the bipolar is more useful if the nerve course is evident.  However, a bipolar stimulator is more precise.    It is a U-shaped gland with a smaller deep lobe and larger  superficial lobe enveloping the mylohyoid muscle. Hence    during surgical removal, the mylohyoid has to be retracted  anteriorly to expose the deep lobe and the Wharton’s duct.  The capsule is loosely attached to the gland substance, and  hence the gland can be shelled out easily.   Since the submandibular group of lymph nodes are in  contact with the gland or embedded in it, it is essential to  clear the nodes along with the gland during a neck  dissection.   The facial artery loops around the submandibular  gland. The facial artery is visualized by retracting the pos-  terior belly of the digastric muscle inferiorly. Hence, dur-  ing excision of the submandibular gland, the facial artery  and vein were customarily ligated. However, during neck  dissection, the current standard is to try and save it so that  it can be used for anastomosis during a free flap  reconstruction.   The facial artery is ligated away from the external carotid  artery, so that in case the vessel retracts into the tissue, it can  be located and religated and bleeding can be controlled. In  case the ligature slips and the facial artery retracts, the poste-  rior belly of the digastric muscle is divided for easy location  of the bleeding vessel.   The lingual nerve passes below the duct and forms a loop  around its outer aspect before inserting into the tongue  mucosa. It is at risk when the deep part of the gland is being  mobilized. The submandibular duct or Warton’s duct is lon-  ger and has a tortous, uphill course. Thus the secretions have  to be emptied against gravity, and there are increased chances  of retention. Also, the mineral content of the secretion is  high, especially calcium content which along with increased  retention of secretions results into higher incidence of calcu-  lus formation and inflammatory pathologies in the subman-  dibular gland and duct.    Deep part of submandibular gland  @©Association of Oral and Maxillofacial Surgeons of India    level than the gland. Hence, they easily get damaged, and  any trauma or infection of the ducts leads to salivary reten-    They are located beneath the mucosa of the floor of the tion and formation of a mucous retention cyst which is called  mouth and appear as an elevation in the floor of the mouth. “ranula” due to its bluish color resembling the belly of a  The excretory ducts of the sublingual glands are very super- frog. The international statistical classification of diseases  ficially located and open in the floor of mouth at a superior and related health problems shown in Table 46.4.    46 Salivary Gland Pathologies  Table 46.4 International statistical classification of diseases and  related health problems    Ranula  K117 Disturbances of salivary secretion  Hypoptyalism  Ptyalism  Xerostomia  Excludes dry mouth NOS  Other diseases of the salivary glands  Benign lymphoepithelial lesion of the salivary gland  Mikulicz’ disease  Necrotizing sialometaplasia  Sialectasia  Stenosis/strictures of salivary ducts  Excludes Sicca syndrome (Sjégren’s syndrome)    A thorough history followed by meticulous examination  holds the key to proper diagnosis of salivary gland patholo-  gies. Salivary gland neoplasms are usually slow growing  and non-tender. A slow-growing swelling of the salivary  gland is suggestive of a neoplasm, whereas a sudden, pain-  ful swelling is suggestive of an infective pathology although  it can sometimes indicate a malignant tumor with second-  ary infection. Nerve weakness and skin infiltration are  always associated with malignant tumors which have  already infiltrated the nerve or skin although the vice versa  is not always true.   Major salivary glands are palpated, and secretions milked  out to check flow, quantity, and quality of secretion. A turbid  salivary discharge may indicate an infection, whereas  reduced salivary flow could indicate either less secretion or  obstruction to flow. Function of facial nerve should be  checked and documented during parotid examination. On  inspection submandibular gland swelling can be easily iden-  tified and compared with the contralateral side; however the  submandibular glands are bimanually palpated (Figs. 46.8  and 46.9).    Various diagnostic aids for investigating salivary gland  diseases are as follows:    1. Diagnostic imaging  (a) Routine radiographs: It is useful only for diagnosing  sialoliths and parenchymal calcifications. Radiopaque  salivary calculi in the gland or duct can be picked up  on plain films such as occlusal X-ray for submandib-  ular gland and duct and a posteroanterior (PA) skull  with blown-out cheeks for parotid calculi.    vasive modality that utilizes non-ionizing radiation,  gives good soft tissue discrimination, has excellent  sensitivity for mass lesions, and can be repeated as  frequently as required. Normal gland is relatively  homogenously hyperechoic than adjacent muscle,  and so is cyst and tumor from parenchyma [12, 13]. It  helps to distinguish a cystic lesion from a solid mass  in space-occupying lesion (Fig. 46.10). USG with  color Doppler is useful to rule out vascular lesions  and also aids in assessing vascularity of lesions.  Sialography: It assesses obstructive pathology by  instillation of radiopaque contrast medium to locate  obstruction in the ductal system. The technique is  more or less obsolete now with the advent of MRI  imaging. It is a technique which involves injection of  a radiopaque dye into the ductal system of the major  salivary glands and taking plain X-rays to see the pat-  tern of the dye into the ductal systems. Most com-  monly the contrast dyes used are iodine based. They  can either be lyophilic (oil based) or aqueous (water  based or water soluble). Lyophilic (oil-based) con-  trast dyes include Lipiodol (iodized poppy seed oil)  and Pantopaque (organic iodine compound). Aqueous  contrast dyes include iothalamate (Conray) and  metrizoate (Triosil). Aqueous-based dyes are most  commonly preferred. Sialography is indicated to  diagnose obstructive pathologies and duct anomalies,  degenerative changes in the gland, chronic inflamma-  tory conditions, and intra- and extraglandular tumors.  It is contraindicated in acute infections of the gland  and in case of allergies to the dye.    Procedure: The duct orifice is enlarged using a  lacrimal probe and cannulated with a 22 gauge can-  nula after infiltrating local anesthetic (Fig. 46.1 1a, b).  The selected dye is injected into the ductal system  using a Luer lock syringe with gentle continuous  pressure with simultaneous massage of the gland.  Once the patient feels some discomfort, dye injection  is stopped. X-rays are taken during the filling phase  and emptying phase as well.   (iv) Stricture in a duct is seen as a filling defect,  whereas multiple strictures show a sausage  string appearance.   (vi) Duct perforation and sialocele show dye spillage  in the soft tissues.   Radionucleotide scanning: It is used to distinguish  between obstructive and nonobstructive sialadenitis.  It involves both dynamic and _ static scanning.  Radionuclide scanning is useful when a sialogram is  contraindicated to distinguish between acute obstruc-  tive and nonobstructive sialadenitis [14].  CT scan: It is used to evaluate masses in parotid  glands and surrounding structures as it gives excel-  lent soft tissue details (Fig. 46.13) especially when  used with a contrast dye. Bony changes in the course  of facial nerve like erosions, sclerotic margins, and  widening of stylomastoid foramen or fallopian canal  suggest involvement of nerve. Plain computed  tomography (CT) scans have a major role to play for  diagnosis of obstructive pathologies like a calculus.   excellent soft tissue contrast. In the case of neo-  plasms, it helps in demonstrating involvement of    Fig. 46.12 Normal parotid gland in sialography : . ;  2. Histopathology: The gold standard of diagnosis for    (h) Positron emission tomography (PET): Uptake of However, as the major salivary glands are deeper struc-  radiotracer fluorodeoxyglucose used with PET scans tures, an FNAC (fine-needle aspiration cytology) is  by salivary glands makes this diagnostic technique considered as a standard of care for diagnosis to avoid  useful for salivary gland tumors. Although this is an tumor seeding, which might follow an open biopsy. An  expensive technique, measurement of metabolic open biopsy can be considered for minor salivary gland  activity makes it more reliable than CT and MRI tumors or malignant tumors affecting major salivary  scans. It can be used to diagnose recurrences, tumor glands with skin infiltration, needing skin excision to    pathologies is very challenging, and hence diagnosing  lesions on FNAC is more difficult. It is important to dis-  tinguish benign and malignant pathologies on FNAC  even if the exact malignant variant is missed, because  except adenoid cystic carcinoma which has perineurial  spread, the surgery doesn’t change for any other malig-  nant tumor variant.    (a) Fine-needle aspiration cytopathology (FNAC): It  shows high diagnostic accuracy both for benign and  malignant tumors. Complete histological features  and status of invasion can’t be revealed by this  technique.   (b) Incisional biopsy: It is not a reliable technique as  there is high possibility of seeding of tumor cells as  well as fungation through skin.    Parotitis (Fig. 46.15) occurs secondary to decreased salivary  secretions, and various reasons are attributed.    Sialadenitis: Sialadenitis is inflammation of the gland parenchyma.  It could either be suppurative (with pus) or nonsuppurative (without  pus). It can also be classified as acute, subacute, or chronic.  Sialodochitis: This refers to inflammation of the salivary gland duct.  It may be associated with duct strictures and/or sialoliths.  Sialectasis: This refers to cystic dilatation of the ducts due to either a  sialolith or ductal strictures. It is most commonly seen in parotid  gland infections. It can occur due to any condition causing chronic  inflammation of the gland.   Sialorrhea: This refers to excessive secretion of saliva or drooling of  saliva. It is most commonly seen in patients with cerebral palsy and  neuro-degenerative disorders.   Sialosis: It is defined as an asymptomatic, non-neoplastic, non-  inflammatory parenchymal salivary gland disease which manifests as  persistent painless bilateral salivary gland swelling, most commonly  involving the parotid gland [16].   Sialodochoplasty: It is repair of the salivary gland duct usually by  translocating the ductal opening.    The common etiologic factors for parotitis are reduced  salivary flow due to severe dehydration, in patients with  debilitating diseases, old age, post-operative patients,  post radiotherapy for head and neck cancers, poor oral  hygiene leading to recurrent infection, mechanical  obstruction to flow, compromised host resistance due to  systemic illnesses like Diabetes Mellitus, renal failure,  HIV, post transplant immunosuppresants. The drugs  which induce systemic dehydration such as antihyperten-  sives, diuretics, tricyclic antidepressants , phenothiazines,  barbiturates, anticholinergics and betablockers also lead  to reduced salivary flow rate [17].    It may be retrograde contamination of salivary ducts and  parenchymal tissues by oral microflora providing a bacterial  source of infection. Stasis of salivary flow through the ducts  and parenchyma may also promote acute suppurative infec-  tion. There is a higher risk of sialolith in the submandibular  duct causing secondary suppurative sialadenitis (Fig. 46.16  showing submandibular sialadenitis).  46.4.1.1 Clinical Features  e Sudden onset of pain and swelling, exacerbates with food   ¢ Generalized malaise, fever, body ache, and sometimes  signs of dehydration.   e Diffuse inflammatory swelling, induration, erythema,  edema, and extreme tenderness over the affected gland.   e The duct orifices are inflamed, and milking of gland may  exhibit lesser salivation or purulence.   e Systemic sepsis occurs more commonly in parotid sialad-  enitis as compared to submandibular sialadenitis.   e Parotid swellings are not fluctuant due to fixity of overly-  ing investing parotideomasseteric fascia and are extremely  painful due to the mounting pressure as the fascia is  nonyielding. This mounting pressure leads to ischemic  necrosis of the gland, and the abscess may spontaneously  burst in the external auditory canal.    Routine blood count to rule out impending sepsis in addi-  tion to a plain radiograph or USG to rule out a sialolith in the  duct is indicated. Sialography is contraindicated in cases of  acute infections and also sialoliths. Aspiration might not  yield frank pus.   Treatment is managing underlying cause and adequate  hydration and systemic antibiotics. If swelling doesn’t sub-  side with medical management in 2 days or shows an increas-  ing trend, an incision and drainage is indicated. The cellulitic  phase may not yield any frank pus, but toxic fluid is drained  and it releases the pressure over the gland and prevents pres-  sure necrosis of the gland parenchyma. Parotid space abscess  has the tendency to spread into the pharyngeal spaces and  cause respiratory distress and descending mediastinitis or  burst into the auditory canal or TMJ and cause septic arthritis  of the TMJ.    It is a recurrent sialadenitis with episodic relapsing swellings  of the salivary glands, most commonly seen in the parotid  gland. Salivary retention and stasis are the main predisposing  factor. It might be preceded by an acute sialadenitis. Strictures  may also form in the ducts leading to salivary stasis and  eventually chronic sialadenitis. Generalized constitutional  symptoms may be low grade, and salivary gland milking  may yield scanty saliva. MRI is more specific than CT scan.   Management consists of short-term corticosteroids to elimi-  nate glandular inflammation followed by use of sialogogues  to increase salivation and flush the debris. Sialoendoscopy  can play a role in increasing the salivary flow.   The sialoendoscope is advanced slowly into the duct  with continuous saline irrigation to help visualize the sys-  tem and also dilating the strictures with help of the sialob-  alloon. This is followed up by placing a stent into the duct  for 4 weeks.   Superficial parotidectomy with facial nerve preservation  can also be considered in case of chronic pain, provided  imaging studies determine the involvement of superficial  lobe.   Chronic recurrent parotitis if left untreated may lead to  benign lymphoepithelial lesion which can progress to lym-  phoproliferative disorders like non-Hodgkin’s lymphoma,  carcinoma, or pseudolymphoma.    Sialolithiasis or salivary calculi are most commonly seen in the  submandibular gland and duct (Fig. 46.17a, b). Symptomatic  calculi are much lesser in occurrence. Only those cases with  superadded infection and inflammation of the gland and duct  result into pain.    46.4.3.1 Etiology  Salivary stasis is a major etiologic factor for formation of  sialolith. The right-angle bend of the Stenson’s duct where it  pierces the buccinator and the 90° bend of the Wharton’s  duct at the border of the mylohyoid is the common location  for sialoliths. They can also result from chronic sialadenitis.  Systemic abnormalities of calctum metabolism are not asso-  ciated with any increased risk of salivary stone formations.  Gout is the only systemic illness known to predispose to sali-  vary stone formation [19].   Salivary stasis changes the mucoid element of saliva to a  gel framework for deposition of salts and organic substances    creating a stone. Unknown metabolic phenomenon increases  salivary bicarbonate content altering the calcium phosphate  solubility and leading to precipitation of calcium and phos-  phate ions [20]. Wharton’s duct is longer than the Stenson’s  duct, and the submandibular gland is situated at a lower level  than the opening of the duct. Hence the duct has to follow an  uphill, tortuous course and drain against gravity. So stagna-  tion of secretions is more common than parotid gland.   In the submandibular gland, the calculus results in sialad-  enitis, whereas in the parotid gland, sialadenitis causes cal-  culus formation. In the parotid gland, stones are most  commonly located at the hilum or parenchyma, whereas sub-  mandibular sialoliths develop in the duct [21]. Sometimes  typically the sialolith is expelled out of the gland through the  duct and is seen at the duct orifice.   Sialography can be used for diagnosis of sialoliths but is con-  traindicated if the calculus is already diagnosed on plain  radiographs. Smaller stones can be expelled out through the    Fig. 46.17 (a, b) Left—Submandibular duct calculus (a). Right—Calculus after surgical removal (b). (¢) Submandibular gland specimen show-    duct opening using local massage, sialogogues, and adequate  hydration. Larger stones are managed surgically according  to its location in the duct and gland.   If the stone is palpable in the oral course of the duct, the  duct is dilated with a lacrimal probe and cut open to retrieve  the stone. The duct margins are sutured to the adjacent  mucosa to avoid stricture formation. A stay suture can be  placed around the duct proximal to the stone to avoid acci-  dental pushing of the stone into deeper inaccessible part of  the duct. In submandibular stones which are at the genu of  the duct or deeper into the gland, a sialadenectomy is needed  (Fig. 46.17c).   If the sialolith is posterior in the duct, a suture is placed  behind the stone to prevent slippage of stone into the duct.  The incision is placed over the duct to extract the stone, and  the duct is left without suturing (Fig. 46. 18a, b).   Sialodochoplasty is a procedure wherein the incised duct  margins are sutured with adjacent mucosa leading to a trans-  location of duct orifice [22, 23].   In the case of parotid sialoliths, only those in the duct  distal to the masseter muscle can be accessed transorally and  removed. All deeper stones warrant a parotidectomy.   Extracorporeal shock wave lithotripsy and use of sialoen-  doscopy are newer modalities to manage sialoliths.  Lithotripsy reduces calculi to small fragments that are then    Line of incision for  anterior stone  ©Association of Oral and Maxillofacial Surgeons of India    flushed out of the duct with spontaneous salivation or use of  sialogogue [24]. The primary requirement for salivary stone  lithotripsy is a functional gland which produces saliva which  will clear the fragmented stone. A “gum test” which involves  chewing of a sour gum can be done to test the functionality  of the salivary gland. If the salivary secretions are normal, a  visible swelling in the region of the gland will be noticed. If  the test is negative, the patient cannot be taken up for  lithotripsy.    Mumps is an acute nonsuppurative viral parotitis caused by  paramyxovirus also known as epidemic parotitis. The term  “mumps” is derived from the Danish word “Mompen” which  means mumbling (like an old man) and describes the diffi-  culty with speech because of inflammation and trismus [17].   It is an endemic disease and spreads by airborne droplet dis-  semination. It has an incubation of 2—3 weeks followed by  3—5-day viremia. The virus localizes to the salivary glands,    Fig. 46.18 (a, b) Technique of sialolith removal from submandibular duct    germinal tissues, and CNS [25]. The infection has a strong  predilection for the parotid gland. It is highly contagious and  occurs in children below 15 years of age with peak incidence  being in the 4- to 6-year-old group of children [26]. Adults  are rarely infected due to the immunity because of childhood  exposure or due to the MMR vaccine [17].   Prodromal symptoms include headache, myalgias, arthral-  gias, anorexia, and malaise prior to development of parotitis.  It starts with an earache, pain around the gland, trismus, and  dysphagia. Pain is exacerbated by salivary stimulation dur-  ing meals. The parotid papilla may be inflamed and puffy.  Palpation of the gland reveals a swelling of the gland which  may be tense, rubbery, and firm with non-pitting-type edema.  The overlying skin is tensed and shiny without erythema or  increased local temperature. Swelling lasts for 1-5 days and  can displace the pinna. Seventy-five percent cases result in  bilateral involvement of parotid gland. However, it begins as  a unilateral swelling and involves the contralateral gland  after a period of 1-5 days [25].   Diagnosis is primarily clinical, but a blood count shows  leukocytopenia with relative lymphocytosis. Serum amylase  levels are also raised. It peaks during the first week and starts  declining in the second or third week and comes back to nor-  mal later [25].   “S” or soluble antibodies directed against the nucleopro-  tein core of the virus appear within the first week of infection  and peak within 2 weeks and disappear within 8—9 months.  “V” or viral antibodies directed against the outer surface  hemagglutinin appear several weeks after the “S” antibodies  and persist at low levels for approximately 5 years following  exposure. A fourfold rise in antibody titer is diagnostic of  active infection. Mumps skin test is not useful in the diagno-  sis of acute infection because dermal hypersensitivity does  not develop until 3 or 4 weeks following viral exposure.   The disease is self-limiting, and treatment is primarily sup-  portive such as rest, adequate hydration, antipyretics, and  anti-inflammatory medicines.   Live attenuated Jerry Lynn vaccine is given combined  with measles and rubella as MMR vaccine after 12 months of  age. Immunized population is less likely to get the disease  but may be infected with a nonparamyxovirus.   Orchitis and oophoritis can occur as systemic manifestations  and rarely lead to complete sterility. Mastitis has been asso-  ciated with decreased lactation. Aseptic meningitis occurs in    10% of cases, and asymptomatic meningeal inflammation is  more common. Five percent patients are affected by acute  pancreatitis, wherein serum lipase levels are also increased.  Sensorineural hearing loss complicates 0.05—4% of patients  and may be permanent and profound [26]. Tinnitus, aural  fullness, and vertigo are associated symptoms, but they  resolve over a period of few weeks. Additional complica-  tions include myocarditis, polyarthritis, hemolytic anemia,  plasmacytosis, lymphocytic leukemoid reactions, and throm-  bocytopenia [12]. These conditions are self-limiting or  resolve with or without steroid therapy.    HIV-associated salivary gland disease is the term used to  describe the diffuse enlargement of the salivary glands that  affects HIV patients throughout all stages of the disease. In  fact, HIV-SGD may be the first presenting sign of HIV. Like  most of the salivary diseases, the parotid gland is the most  frequently affected. Clinically, HIV-infected individuals  show reduced salivary flow rates. Parotid gland enlargement  is reported to occur in 1-10% of the HIV-infected popula-  tion. It is usually secondary to development of benign lym-  phoepithelial cysts within the parotid gland [25].   Antiretroviral therapy with zidovudine, maintenance of oral  hygiene, and use of sialogogues form the mainstay of  management.    Mikulicz’ disease and Sj6gren’s syndrome are closely related  to each other and are autoimmune in origin, wherein the sali-  vary tissue itself becomes antigenic [27].   Middle-aged females are affected commonly. It behaves  like an inflammatory as well as a neoplastic disease.  Presenting symptoms may be diffuse, poorly outlined, uni-  lateral or bilateral enlargement of the parotid or subman-  dibular glands with an occasional increase or decrease in  size of the swelling. There is mild local discomfort, occa-  sional pain, and xerostomia. Fever, upper respiratory tract  infection, tooth extraction, or some other local inflamma-    tory disorder may precede the disease. Sometimes the lac-  rimal glands may be enlarged. FNAC can help diagnose the  condition.   Mild cases once diagnosed do not warrant any treatment. In  some cases, the swelling might regress spontaneously.  Persistent cases can be managed by sialadenectomy [28].    Sjogren’s syndrome or Sicca syndrome is a chronic autoim-  mune disorder of the exocrine glands involving multiple  extraglandular sites and can even evolve into a lymphoid  malignancy. Sjégren’s syndrome shows a triad of symp-  toms—keratoconjunctivitis sicca, xerostomia, and a sys-  temic disease, usually but not always rheumatoid arthritis.  Primary Sjégren’s syndrome also known as Sicca complex  presents with only dry eyes and dry mouth. Secondary  Sjégren’s syndrome has in addition to the above features sys-  temic manifestations such as systemic lupus erythematosus,  polyarteritis nodosa, polymyositis or scleroderma, and rheu-  matoid arthritis [28].   Arthritis is the most frequent first complaint, followed by  ocular complaints and then xerostomia which leads to diffi-  culty in chewing and swallowing, sore mouth, recurrent den-  tal caries, and fungal infections in the oral cavity. The tongue  appears bald with loss of filiform papillae and fissuring of  tongue. The saliva is usually cloudy due to pus and abnor-  mally viscous due to gel-like consistency. Parotid gland  enlargement is seen in 25-66% cases of primary Sjégren’s  syndrome but is uncommon in secondary cases. Xeropthalmia  leads to chronic irritation and destruction of the corneal and  bulbar conjunctival epithelium, referred to as_ kerato-  conjunctivitis sicca. The patient complains of redness, itchi-  ness, or burning sensation in the eye, rope-like secretions,  dryness, and a foreign body sensation in the eye and may not  be able to tolerate smoke, air draft, or light [27].   Schirmer’s test is used to confirm lacrimal secretions.  Patients complain of easy fatigue, general malaise, low-  grade fever, myalgias, and arthralgias. Respiratory tract  symptoms range from dry cough due to xerotrachea to dys-  pnea due to interstitial disease or even airway obstruction.  High-resolution CT scan shows bronchial and peribronchial  thickening, whereas transbronchial biopsies show bronchio-  lar lymphoid infiltrates and follicular bronchiolitis [29].  Sensorineural hearing loss is associated with Sjégren’s syn-  drome in 21-46% of cases [30]. Dysphagia results from dry-  ing of the pharynx and esophagus. Other complications    include renal disease, Raynaud’s disease, inflammatory vas-  cular disease, peripheral sensory or sensorimotor polyneu-  ropathy or mononeuritis multiplex, skin dryness, vasculitis,  and frequent allergic reactions. Labial salivary gland biopsy  is used as a means of assessment of salivary pathology in  SjOgren’s syndrome.   Xerostomia and keratoconjunctivitis sicca are managed by  use of 0.5% methylcellulose artificial saliva and tears.  Preventive dental care and fluoride application and mainte-  nance of general hygiene are necessary. Eye patching and  boric acid ointment can be used for corneal ulcers.  Pilocarpine hydrochloride can be used as a secretagouge  for management of xeropthalmia and xerostomia. Systemic  corticosteroids can be used for systemic complications  such as vasculitis, glomerulonephritis, and interstitial lung  disease.    Mucous retention cyst arises from ductal obstruction in a  minor or accessory salivary gland due to traumatic severance  of the duct due to biting of the lips, cheeks, and tongue or  due to injury due to lip pinching during extraction. Majority  of cases are an extravasation type of cysts which result from  collection of salivary secretions in the soft tissues due to  traumatic injury to the gland or duct. Lower lip was affected  in 44-79% of cases. It occurs in any age with no gender pre-  dilection [31].   Superficial lesions appear like a circumscribed, raised ves-  icle with a bluish translucent hue due to the thin overlying  mucosa. However, deeper lesions being covered by normal  mucosa have a normal color and texture. Mucoceles may  get traumatized and rupture spontaneously and may recur  later.    46.6.3.2 Management  Surgical excision of the mucocele along with a few normal minor  salivary glands is the procedure of choice. Care should be taken  to avoid creation of any other partially transected minor salivary  glands which might give rise to the recurrent mucocele.  Mucocele can be excised by giving an elliptical incision  around the lesion and closure (Fig. 46.19a—d), [32] or as the  case requires, an incision may be given over the mucocele;  lesion can be excised carefully without rupture and closure  attained (Fig. 46.19e—h).    Huang I et al. [33] recommended use of carbon dioxide  laser vaporization to treat the lower lip mucocele with good  results and less complications.    Ranula is a mucocele arising from the sublingual salivary  gland in the floor of the mouth (Fig. 46.20). It presents as  a large blue, tense vesicle in the floor of the mouth. The  appearance is of that of a frog’s belly, hence the term  ranula (frog belongs to genus Rana). It is firm on palpa-  tion. The cyst is usually present above the mylohyoid  curtain, but when it presents in the upper part of the neck,  it is called as a “plunging ranula.” Plunging ranulas  may grow to a sufficient size so as to compromise respi-  ration and swallowing and may also extend into medias-  tinum [32].    46.6.4.1 Management  Excision of the ranula and entire sublingual gland through a  transoral approach is management of choice taking care to  avoid damage to the lingual nerve. The incision is made  through the mucosa in the lingual fold from the second molar  to canine tooth. Blunt dissection is done up to the mylohyoid  muscle. The gland is dissected free from the surrounding soft  tissues and the Wharton’s duct. The gland can be retracted  using holding sutures, and blunt dissection is carried out till  the lingual nerve is identified as it crosses the Wharton’s  duct. The gland is delivered once it is dissected free from the  entire surrounding soft tissues taking care to prevent damag-  ing the submandibular duct and lingual nerve [34].  Marsupialization can be used as an alternative modality  wherein the ranula is deroofed and the mucosa sutured to the  cystic lining followed by open packing of the cyst and  sequentially reducing the size of the pack till it heals  completely.    Fig. 46.19 (a)-(d) Figure showing surgical removal of mucocele by elliptical incision. (e)-(h) Figure showing excising mucocele by incision    Higher recurrence rate (61-85%) has been reported with  simple marsupialization and ranula excision. To lower the  rate of recurrence, total sublingual excision is the treatment  of choice [35].   Kono et al. [36] recommended an injection of sclerosing  agent, OK-432 (Picibanil), as a safe and effective method of  treating intraoral ranulas. The number of injections used was  1-4 (mean 1.70) in their study.    Although no specific etiology has been attributed to occur-  rence of salivary gland tumors, its association with radia-    e Radiation: Evidence exists regarding susceptibility of  lymphoid component rather than parenchymal compo-  nent of gland to low radiation and UV ray damage  (140 rad) [37-39].   e Viruses: It is believed that genetic component, environ-  ment, and immunity of host play a key role in malignant  transformation of salivary gland tumors. Viruses like  human papillomavirus, Epstein-Barr virus, cytomegalovi-  rus, and polyomavirus have been speculated to be respon-  sible for occurrence of salivary gland tumors.   ¢ Hormones: Endogenous hormones play an important role  in carcinogenesis of these tumors. Patients of breast can-  cer are more prone to salivary gland neoplasms.    e Lifestyle: Tumors like Warthin’s tumor or epidermoid  carcinoma have been associated with cigarette smok-  ing. Salivary gland enlargements are observed in nutri-  tional deficiencies, but there are no reports of  malignancies [40].   ¢ Occupation: Those who engage in occupations which  involve manufacturing and use of rubber products, asbes-  tos mining, and plumbing are at increased risk of develop-  ing salivary gland tumors [37].    Salivary gland tumors occur rarely both among Indian pop-  ulation and around the world. Incidence of benign and  malignant salivary gland tumors in major portion of the  world ranges from | to 2 cases per 100,000 people per year  [41]. There is no specific predilection of occurrence of  these tumors in any particular gender, although Warthin’s  tumor is more common in males and acinic cell tumor in  females. Site wise incidence varies for both benign and  malignant tumors. Seventy-five to eighty percent of benign  tumors occur in the parotid glands, 5—10% in submandibu-  lar glands, and only 1—2% in sublingual glands. Malignant  tumors are more common in sublingual glands (80%) and  least in parotid glands (17-20%). Benign tumors affect a  mean age group of 40 years, and malignant tumors affect an  age group of 55 years. Both benign and malignant tumors    by large resemble each other clinically. Hence, histopatho-  logic examination is pivotal to establish a _ correct  diagnosis.    46.7.3 TNM Staging of Salivary Gland Tumors  According to American Joint  Commission on Cancer (AJCC) 2002 [42]    Tumor (T): T with a letter/number describes the location or  size of the tumor   TO (T plus zero): No evidence of a tumor was found.   TI: Describes a small, noninvasive (has not spread) tumor  that is 2 centimeters (cm) at its greatest dimension.   T2: Describes a larger, noninvasive tumor between 2 cm and  4 cm.   T3: Describes a tumor that is larger than 4 cm but not larger  than 6 cm and has spread beyond the salivary glands but  does not affect the seventh nerve, the facial nerve that  controls expression, such as smiles or frowns.   T4a: The tumor has invaded the skin, jawbone, ear canal,  and/or facial nerve.   T4b: The tumor has invaded the skull base and/or the nearby  bones and/or encases the arteries.    Nodes (N): N is for lymph nodes. Lymph nodes of the head  and neck region are regional lymph nodes, and those  away from this region are distant nodes.   NO: There is no evidence of cancer in the regional nodes.   NI: Cancer has spread to a single node on the same side as  the primary tumor, and the cancer found in the node is  3 cm or smaller.   N2: Describes any of these conditions:  ¢ N2a: The cancer has spread to a single lymph node on   the same side as the primary tumor and is larger than   e N2b: The cancer has spread to more than one lymph   node on the same side as the primary tumor, and none   e N2c: The cancer has spread to more than one lymph  node on either side of the body, and none measures  larger than 6 cm.   N3: The cancer found in the lymph nodes is larger than  6 cm.    Metastasis (M): Describes the cancer that spreads to differ-  ent body parts.  Mx: Indicates distant metastasis cannot be evaluated.    MO: Indicates the cancer has not spread to other parts of the  body.   M1: Describes cancer that has spread to other parts of the  body.    Salivary gland tumors were first classified by WHO in 1972.  It was later modified in 1991 wherein the term “tumor” was  replaced by “carcinoma” to denote acinic cell carcinoma and  mucoepidermoid carcinoma [43]. It was further revised in  1997, and a greater number of entities of adenomas (myoepi-  thelial adenoma, basal cell adenoma, canalicular adenoma)  and carcinomas (acinic cell carcinoma, mucoepidermoid  carcinoma, polymorphous low-grade adenocarcinoma, sali-  vary duct carcinoma, myoepithelial carcinoma) were rede-  fined with emphasis on the prognosis and therapy [44]. A  revised classification was put forth by WHO in 2005 also.  The latest classification of WHO which was given in 2017  consisted of the following changes:   e Simplification of terminologies of polymorphous adeno-  carcinoma, clear cell carcinoma, and intraductal carci-  noma was done.   e Rare entities like adenocarcinoma, NOS, canalicular ade-  noma, and poorly differentiated carcinoma were  regrouped (Table 46.6).    “Pleomorphic adenoma” suggested by Willis closely resem-  bles the unusual histologic pattern of the lesion [28]. The  tumor derives its name from the Greek words Pleos = many  and morphus = form because of the heterogeneous nature of  its histologic appearance [46].   Most frequently found in the superficial lobe of the parotid  gland, it presents as a firm, slow-growing asymptomatic  mass which is smooth, rounded, lobular, and mobile with a  rubbery consistency causing ear lobule to be raised  (Fig. 46.21a). If the tumor involves both the superficial and  deep lobes of parotid, it is classically referred to as dumbbell  tumor. Incidence of the tumor except those found in the phar-  ynx is more in females than males, and they are often seen in  the fourth and fifth decade. A bilateral tumor occurrence rate  is estimated at 1 in 40,000 [47].    Malignant Tumors  Mucoepidermoid carcinoma  Adenoid cystic carcinoma  Polymorphous adenocarcinoma  Epithelial-myoepithelial  carcinoma   Basal cell adenocarcinoma  Sebaceous adenocarcinoma  Intraductal carcinoma  Cystadenocarcinoma  Adenocarcinoma, NOS  Myoepithelial carcinoma    Carcinoma ex pleomorphic  adenoma  Carcinosarcoma  Poorly differentiated carcinoma  1) Neuroendocrine and  non-neuroendocrine  2) Undifferentiated carcinoma  3) Large cell neuroendocrine  carcinoma  4) Small cell neuroendocrine  carcinoma  Lymphoepithelial carcinoma  Squamous cell carcinoma  Oncocytic carcinoma  Borderline Tumors    Sclerosing polycystic adenosis  Nodular oncocytic hyperplasia  Lymphoepithelial lesions  Intercalated duct hyperplasia  Soft Tissue Lesions  Hemangioma    They are encapsulated and do not show fixity to the deeper    tissues or the overlying skin in major salivary gland tumors,  which can be confirmed on an MRI (Fig. 46.21b), but in the case  of the minor salivary glands of the palate, it may appear to be  fixed to the underlying palatal bone but does not invade or erode  the bone. Pain is uncommon but 50% patients experience a pres-  sure sensation. Accumulation of mucus can occur so that elastic  swellings or frankly fluctuant cysts may form in the tumors.   In the case of the submandibular gland, palpation of the  mass both extraorally and bimanually helps in localizing it  and differentiating it from a lymph node, but FNAC is always  needed to differentiate it from sialadenitis.   On light microscopy morphologically complex and diverse  cellular elements are seen. Both epithelial and myoepithelial  elements are present. Based on cellular types, Foote and Frazel  [49] have classified pleomorphic adenomas as follows:    Fig. 46.21 (a) Parotid tumor showing elevation of ear lobule (pathognomonic sign). (b) MRI axial view showing the tumor    46.7.5.3 Management  Surgical excision is the treatment of choice. Historically,  enucleation was practiced which resulted in inadequate sur-  gery and recurrences [50]. Superficial parotidectomy is the  most widely accepted technique in the treatment of pleomor-  phic adenomas in the superficial lobe of the parotid gland,  and total gland excision with facial nerve preservation is car-  ried out. Tumors of the submandibular gland are usually con-  tained within the gland, and their resection is usually confined  to the gland and surrounding fat or lymph nodes until the  neoplasm is a malignant and invasive tumor. As with the  parotid gland, most neoplasms are asymptomatic. Small pal-  atal pleomorphic adenomas usually cause pressure resorp-  tion of the palate but do not invade the bone. A disk of palatal  mucosa is outlined well clear of the visible swelling because  the tumor is flattened owing to the toughness of the palatal  tissues. The tumor along with the periosteum of the palate is  excised in continuity with each other. In case the pleomor-  phic adenoma invades the palate or proliferates into the floor  of the maxillary sinus, a partial maxillectomy or total maxil-  lectomy depending on the extension of the tumor has to be  performed.   Although pleomorphic adenoma is a benign tumor, it may  cause problems in clinical management due to its tendency  to recur and risk of malignant transformation.    The WHO classification subdivides the monomorphic ade-  nomas into three groups [45]:    A number of other classifications of monomorphic adeno-  mas have been put forth, but there is no unanimity. Two main  histologic patterns have evolved:    Warthin’s tumor, also known as papillary cystadenoma lym-  phomatosum and adenolymphoma, is the second most com-  mon benign tumor of the salivary glands, around 5% of  neoplasms [51].   It was first described by Hildebrand in 1895 as a form of  congenital cyst of the neck. It is known as Warthin’s tumor in    recognition of the pathologist who first described it in the  USA in 1929. He described two cases and also coined the  term papillary cystadenoma lymphomatosum [52].   The majority of the tumors arise in the parotid gland,  more often bilaterally, in the elderly and occurs in the fifth  and sixth decades of life. A predilection for male sex is  seen, more in Caucasians. Both tumors do not occur  simultaneously but are metachronous in their manifesta-  tion. A concept of multicentric and multifocal disease has  been put forth to explain this. It is a solitary, nodular,  slowly enlarging swelling, most commonly located in the  inferior pole of the parotid next to the angle of the man-  dible. It varies from moderately firm to fluctuant on palpa-  tion and is asymptomatic. It is not as discrete as the mixed  tumor. Very few patients present with complain of pain,  pressure, or rapid increase in the tumor size. Scintigraphy  may be helpful due to its increased uptake of technetium-  99m pertechnetate. It appears as a smooth-margined,  radiopositive “hot” nodule in contrast to the mixed tumors,  nonfunctioning malignant tumors, and metastatic tumors  which appear as a “cold” nodule in scintigraphy. Positive  scintigraphy with 'I is indicative of Warthin’s tumor but  may also signify presence of ectopic thyroid or metastatic  thyroid tumor.    46.7.7.2 Management  Surgical removal is the established treatment for Warthin’s  tumor. As the tumor is superficial in the parotid gland, it is  easily removed with minimal loss of glandular function and  with preservation of the facial nerve.    ¢ Tumor enucleation with resection of minimal amount of  surrounding normal tissue    Local excision of the tumor is preferred to enucleation of  the tumor because lymph nodes at the posteroinferior part of  the gland cannot be cleared by enucleation. Preoperative  diagnosis of Warthin’s tumor must be confirmed by coordi-  nating the clinical findings with imaging and fine-needle  aspiration biopsy reports before local excision is carried out.  If there is associated chronic obstructive parotitis, superficial  parotidectomy is essential. Similarly, if the tumor is located  in front of the ear, a superficial parotidectomy is the treat-  ment of choice.    An oncocytoma is a tumor characterized by large epithelial  cells, i.e., oncocytes that contain a brightly eosinophilic, gran-  ular cytoplasm. The oncocyte is derived from the Greek word  “onkousthai” meaning swollen or enlarged and was described  in 1897 by Schaffer who observed this tumor in ductal and  acinar elements of salivary glands in the tongue, pharynx, and  esophagus. Jaffe was the first to introduce the term oncocy-  toma [53]. However, he had termed Warthin’s tumor as onco-  cytoma. The other terminologies used to describe this tumor  are oxyphilic adenoma and acidophilic adenoma.   There is no race predilection for occurrence of this tumor.  Oncocytoma is predominantly a tumor of the major salivary  glands, parotid being the most common. Bilateral occurrence  is also known. Among minor salivary glands, which are  rarely affected, palatal mucosa followed by buccal mucosa  and tongue is affected.   The oncocytoma is a small benign lesion which generally  does not attain a great size. It most frequently presents as an  indolent, single, often multi-lobulated, firm, solid, and mobile  mass in the superficial lobe of the parotid gland. It can also be  located in the deep lobe of the parotid gland and may be insin-  uated between the branches of the facial nerve. However, it  does not cause any symptoms of pain or paresthesia unless the  branches of the facial nerve are compromised. Tumor size var-  ies with the duration of the lesion but generally does not  increase beyond 4.0 cm. Intraoral tumors do not exhibit any  special characteristic diagnostic features. However, their over-  lying mucosa may become ulcerated due to trauma [53].   Partial parotidectomy with facial nerve preservation when-  ever possible is the treatment of choice. It ensures complete  removal of the tumor and reduces the rate of recurrence.  Curettage or simple enucleation of the tumor is to be avoided  to avoid recurrence. Complete sialadenectomy is the treat-  ment of choice in cases of submandibular gland oncocyto-  mas. In the case of minor gland tumors, local excision of the  tumor with a margin of normal tumor-free tissue is carried  out. Radiation therapy after surgery has been tried but it has  shown to be ineffective.    It was first reported as a separate entity by Kleinsasser and  Klein in 1967 [28].    46.7.9.1 Clinical Features  Basal cell adenomas occur between the third and ninth  decade, but the peak incidence is in the sixth decade with a  slight male predilection of 5:1 [28]. They are clinically indis-  tinguishable from mixed tumors and occur in the superficial  portion of the parotid gland. They are slow-growing, painless,  round or ovoid, well-circumscribed, and freely mobile masses  with a smooth-surfaced capsule and a soft to moderately firm  consistency. They may be mistaken for a hyperplastic lymph  node because of their encapsulation, size, and color.   Clinically basal cell carcinoma of skin, ameloblastoma,  pleomorphic adenoma, and adenoid cystic carcinoma can be  considered in the differential diagnosis.   On the basis of histopathologic appearance, they may be  divided into four subtypes:    46.7.9.2 Management  Surgical excision with a sufficient clear margin of normal  tissue is the treatment of choice.   It is seen between the fourth and ninth decade, highest inci-  dence being in the seventh decade with a female/male ratio  of 1.7 to 1.0 and a higher incidence in Caucasians. It is seen  more commonly in the minor salivary glands of the lip and  cheek and rarely affects the major salivary gland [54].   It presents as a non-ulcerated, painless, mobile nodule  that exhibits slow growth unless it is traumatized, wherein  there is presence of ulceration. Clinical appearance is similar  to that of a mucocele [54]. The overlying mucosa may be  normal colored or bluish.   In the case of upper lip lesion, a sialolith, mucocele,  mucous retention cyst, and pleomorphic adenoma can be  considered in the differential diagnosis.   Surgical excision, enucleation, or limited extracapsular exci-  sions have been used as treatment modalities in these tumors  with success.    First described by Abrams and Finck in 1969, it was termed  sialadenoma papilleferum because of its histologic similarity    46.7.11.1 Clinical Features  Sialadenoma papilleferum presents as a subcentimetric,  asymptomatic, exophytic, papillary surface lesion which can  be confused with squamous papilloma. The most common  site of occurrence is the minor salivary glands at the junction  of soft and hard palate with the tumor located on one side of  the midline. This tumor occurs at an average age of 56 years,  cases being reported from 2 years to 87 years. Male predilec-  tion is seen in the ratio of 1.5 to 1. However, there is no racial  predominance [55].   Clinically it resembles a squamous papilloma, and a dif-  ferential diagnosis of verrucous carcinoma or a warty dys-  keratoma needs to be considered.   Being small, these tumors are easily excised usually with a  clinical diagnosis of a squamous papilloma. However, recur-  rence is rare.   Inverted ductal papilloma is a rare tumor and was first  described by White et al. in 1982 when they reported four  cases [56].   It occurs as a firm, asymptomatic, discrete nodule of  1—1.5 cm beneath the normal mucosa which in some cases  may be contiguous with a small surface pore. The mean age  of occurrence is 50 years without any sex predilection. The  sites usually involved are the lower lip and buccal vestibular  mucosa in descending order with occasional cases reported  in the upper lip, floor of mouth, and soft palate.    46.7.12.2. Treatment and Prognosis  It is treated by simple surgical excision as it is not known to  recur.   It is a rare tumor. These tumors present as asymptomatic,  submucosal swellings that vary in size from less than 1 to  1.5 cm in the minor salivary glands. The ages of patients  range from 29 to 77 years, with a mean age of 54 years. Men  and women are equally affected.    46.7.13.1 Treatment and Prognosis  Excision 1s curative, and these tumors are not known to recur.  In case the tumors are small, all types of papillomas of the    minor salivary glands, including intraductal, inverted, and  sialadenoma papilliferum, can be excised in the dental office  or the clinic under local anesthesia [55].    Mucoepidermoid carcinoma is the most common malignant  salivary gland neoplasm. They are classified as grade I (low  grade) which are well differentiated, grade II (intermediate  grade) which are moderately differentiated, and grade II  (high grade) which are poorly differentiated tumors.   Mucoepidermoid carcinomas occur more commonly in the  minor salivary glands with a female predilection [57]. It  occurs as a painless, circumscribed, mobile solitary enlarge-  ment of the body or tail of the parotid or the submandibular  region with over a year duration generally. Pain, facial paral-  ysis, and fixation to the overlying skin are usually suggestive  of high-grade lesions [57]. Minor salivary gland lesions pres-  ent as a bluish or red-purple, fluctuant, smooth-surfaced  mass that is often clinically mistaken for a mucocele or hem-  angioma [57]. Large lesions at the base of the tongue or in  the oropharynx may cause dysphagia. Aggressive tumors  show ulceration. Numbness of the teeth may occur when the  bone is involved. Histopathologically, mucoepidermoid car-  cinomas are graded as low-grade, intermediate-grade, and  high-grade carcinomas. They are generally partially encap-  sulated and don’t show adequate circumscription.   Complete, adequate, and radical surgical excision is the  treatment of choice for all grades of mucoepidermoid  carcinomas [58]. In the case of stage I and stage IT muco-  epidermoid carcinomas of the parotid gland, conservative  excision with preservation of the facial nerve, if possible,  is recommended. The affected submandibular gland  should be removed entirely. Radical neck dissection is  performed in patients with clinical evidence of cervical  node metastasis and is considered in any patient with a  T3 lesion. In the case of facial nerve involvement, total  parotidectomy with facial nerve sacrifice up to histologi-  cally tumor-negative nerve trunk is done. The 5-year dis-  ease-free rate in patients receiving this aggressive  treatment was about 60% [58].   Treatment of minor salivary gland mucoepidermoid  carcinomas entails a wide surgical excision with the bone  if involved, to achieve a negative margin, and the wound is  left to heal secondarily [59]. For small low-grade tumors  in the absence of bone involvement, wide excision down to  periosteum with | or 2 cm tumor-free lateral margins is    adequate therapy [59]. High-grade and advanced stage  tumors must be treated aggressively at any site. The over-  all recurrence rate of mucoepidermoid carcinomas is  approximately 25%. Better survival is seen among younger  patients and among females. Tumors in the submandibular  gland and in the base of the tongue generally have a poorer  outlook than those at other major and minor salivary gland  sites. Also invasion into bone signifies a poorer prognosis.  Survival is closely related to the clinical stage and the his-  tologic grade.    Adenoid cystic carcinoma (ACC) is a highly aggressive,  destructive, and clinically unpredictable tumor of the head  and neck region [60]. The other terms used for ACC used  in the past are cylindroma and adenomyoepithelioma.  Foote and Frazell [49] proposed the currently accepted  term adenoid cystic carcinoma in their classic paper in  1953 and in their fascicle on major salivary gland tumors  in 1954.   Adenoid cystic carcinoma occurs in adults between 50  and 70 years of age with equal prevalence in males and  females [61]. The most frequent locations of this tumor  are the parotid, submandibular, and palatal salivary glands  [62]. They are only rarely observed in the sublingual  gland [61].   Clinically adenoid cystic carcinoma manifests in the  major and intraoral accessory salivary glands as a slow-  growing swelling or mass. Pain and fixation to skin as  well as surrounding deeper structures generally occur  during the course of tumor growth. An ominous feature  of adenoid cystic carcinoma of the parotid gland is paral-  ysis of the facial nerve. Radiographic examination is  valuable in assessing the extent of osseous destruction.  Symptoms may have been present for months or years  and are generally of longer duration than those associated  with squamous carcinoma, which is the most frequent  malignancy of this location. Adenoid cystic carcinomas  of the maxillary antrum, nasal cavity, and ear canal pro-  duce symptoms of pain, obstruction, and deafness,  respectively.   Histopathologically, ACC are classified into cribriform  pattern, tubular pattern, and solid pattern. A major micro-  scopic feature in most adenoid cystic carcinomas is the pro-  pensity for the tumor to involve peripheral nerves, reported  to occur in 20-80% of the patients. Although perineural inva-  sion is characteristic of adenoid cystic carcinoma, it is not  unique to the tumor.   Complete excision like all other tumors is the treatment of  choice. Elective regional lymph node dissection is not  indicated, because distant metastasis is more common  than cervical (regional) node involvement. According to  Maciejewski et al., radical surgical excision with histo-  logically proven negative margins with postoperative  radiotherapy for all cases should be the treatment of  choice. Lymph node dissection is recommended only in  cases of histologically proven positive lymph nodes [60].  A frozen section diagnosis to achieve tumor-free safe  margins is necessary to specifically look for safe perineu-  ral margins because ACC is known to spread quickly  along the nerve.   The slow biologic growth of adenoid cystic carcinoma  along with a late metastasis of the disease results in relatively  favorable 5-year survival rates. Factors that indicate a poor  prognosis include failure to achieve clear margins at first sur-  gery, a solid pattern histologically, recurrent disease, and dis-  tant metastasis [63].   In a study by Witten et al., local recurrences have been  seen in almost 32% of the cases [63]. The risk of distant  metastasis is also high, approximately 40%, and can occur in  less than 8 years after treatment.    Clear cell neoplasms of salivary glands have been classified  as both adenomas and carcinomas [64].   It occurs predominantly in the palatal minor salivary glands  followed by parotid and submandibular glands without any  sexual or racial predilection. It occurs between the ages of  18 and 86 years, mean 56 years. Clinical manifestation is of  a swelling similar to other tumors. It may be confused with  mucoepidermoid and acinic cell carcinoma as well as meta-  static renal cell carcinoma. A positive reaction to mucicar-  mine would preclude the possibility of renal cell  carcinoma.   Due to their infiltrative growth and the incidence of recur-  rence and regional lymph node metastases, it is appropriate  to consider them low-grade adenocarcinomas. Hence surgi-  cal treatment is the mainstay of management.    The epithelial-myoepithelial carcinoma of intercalated duct  origin is a rare biphasic type of low-grade salivary gland car-   It occurs more commonly in females around 60-70 years of  age. Parotid gland is the most frequently affected [65].  Patients present with an asymptomatic or painful salivary  gland swelling with a history of steady increase in size over  an extended period of time and may also present with facial  paralysis [66]. In patients with maxillary involvement, nasal  obstruction and facial deformity may be the presenting  complaints. Differential diagnosis includes pleomorphic  adenoma, acinic cell adenocarcinoma, adenoid cystic carci-  noma, mucoepidermoid carcinoma, sebaceous carcinoma,  and oncocytoma.   Surgery is considered the primary mode of treatment. Total  parotidectomy with facial nerve preservation is advocated  for tumors in the parotid gland unless the nerve is involved  by the tumor. Recurrences and distant metastasis are a known  complication.    Carcinosarcoma, also known as true malignant mixed tumor,  shows malignant cells in both the stromal and epithelial  components [67]. When these tumors metastasize, both com-  ponents metastasize together.   Carcinosarcomas are rare tumors with an average incidence  of 0.4% in major salivary glands and 1% in minor salivary  glands. It occurs between 25 and 85 years of age (average  58.5 years) with the frequency of occurrence being more in  parotid than submandibular gland and then minor glands in  palate and tongue [67].   It presents as an enlarging mass with a rapid increase in  size and may be associated with pain and facial nerve paraly-  sis. Rarely, patients present with metastases or experience  difficulty in swallowing or breathing. A patient with a central  nervous system metastasis has been reported to present with  headaches [67].   The data available is insufficient to recommend one type of  therapy as definitive. However radical surgical excision,  together with radiation therapy and lymph node dissection  for palpable disease, seems to be the most prudent form of  therapy. Radiotherapy as the only means of therapy has not  proved effective. Tumor metastasis is most frequent to the  lungs followed by hilar and cervical lymph nodes. Distant  metastasis is also rarely found [67].    1. Lymphoepithelial carcinomas (malignant lymphoepithe-  lial lesion): It is more prevalent in females and occurs  between fourth and fifth decade of life. The parotid gland  is most commonly involved followed by submandibular  gland. Painful indurated mass and occasional facial paral-  ysis are the presenting symptoms. It might be preceded by  benign lymphoepithelial lesion for many years. It is man-  aged by wide surgical excision with or without neck dis-  section and may be supplemented with radiotherapy.   2. Undifferentiated large cell carcinomas: It occurs predom-  inantly in older population with a male predilection. It  most commonly affects the parotid followed by subman-  dibular and minor salivary glands. Histologically it shows  predominantly poorly differentiated large cell compo-  nents. It carries a poor prognosis and has a higher risk of  locoregional as well as distant metastasis and recurrences.  The worst prognostic factor is the size of the lesion. Less  than 4 cm, mean survival time was 46 months, and more  than 4 cm it was reduced to 7.7 months [51].   3. Undifferentiated small cell carcinomas: It rarely affects the  salivary glands and is primarily a pulmonary tumor. When  it occurs, it shows a male preponderance and occurs  between fifth and seventh decade, in the parotid mainly fol-  lowed by submandibular gland. It presents as a rapidly  growing mass which may or may not be painful.  Management is primarily wide surgical excision with neck  dissection for clinically positive neck node involvement.  Chemoradiotherapy may be used as an adjunctive modality  for treatment. It tends to metastasize via the hematogenous  route, and hence a distant metastasis needs to be ruled out.    The diagnosis of primary squamous cell carcinoma is limited  to the major glands because distinction between possible  minor salivary gland primary tumors and those originating  from mucosal surface epithelium is generally not possible.    46.7.20.1 Clinical Features  It occurs between 7 and 95 years of age, the mean age being  60.5 years with a male predilection of 2:1. Parotid gland is the  most commonly involved followed by submandibular and sub-  lingual glands [68]. It presents as an asymptomatic mass with  occasional pain and facial nerve palsy. This tumor often replaces  the entire gland with fixation to underlying structures and skin.  Ductal squamous metaplasia, high-grade mucoepider-  moid carcinoma, and lymphoepithelial carcinoma should be  considered in the differential diagnosis of squamous cell car-  cinoma of the salivary gland.   Surgical management is the mainstay of treatment.  Parotidectomy with or without facial nerve preservation  depending on the case is needed for parotid tumors.  Submandibular sialadenectomy is needed for submandibular  gland tumors. A neck dissection is done in clinically positive  necks at the slightest suspicion. Locoregional failure is the  most significant problem, and hence a composite resection in  larger submandibular malignancies might be needed.  Postoperative radiotherapy when combined with surgery  may improve the locoregional control [68].    The following procedures are performed:  ¢ Local excision of the parotid gland    The ideal incision should combine good exposure with the  best ultimate cosmetic result. This part of the procedure is  common to all the resection procedures unless skin is being  excised because it is involved by the tumor.   Gutierrez (1903)—The incision had a temporal extension,  a preauricular component, and a limb extending onto the  neck in one of the skin creases (Fig. 46.22). The chief draw-  back of this incisions was esthetics in case of development of  a keloid.   Redon and Vaillant and Laudenbach—The incision line is  similar to that proposed by Adson (Fig. 46.23).   Adson and Ott have described a “Y’’-shaped incision with  a preauricular part, a postauricular part, and a cervical inci-  sion line that splits off from the site of union of the first two  branches (Fig. 46.24). The advantage of this incision is  improved esthetics because it lacks a temporal incision line,  but the drawback is that it impairs dissection. Also, one sec-  tion of the incision is located in the carotid region.   Samengo (1961)—The incision has a preauricular, a post-  auricular, and a neck extension in the incision line  (Fig. 46.25).    Appiani (1967)—The incision within the lower portion  of the scalp is hidden by the hair instead of the vertical inci-  sion line. The benefit of this incision is better esthetics.  However, the temporal extension of this incision is short,  and this impairs access to the anterior portion of the gland  (Fig. 46.26).    Ferreria JL et al. [69] modified Appiani’s incision by  extending the temporal incision line but not beyond the hair-  line. It provides a better access to the anterior portion of the  parotid gland without compromising esthetics. Also, the  angles are rounded off where the incision line changes direc-  tion reducing dehiscence and salivary fistula formation.    Farrior et al. recommended a single curved incision  1.5-2.0 cm below the mandible and extending over the  mastoid region 1.5 cm behind the postauricular crease in  children. The preauricular crease used in adults is avoided  because of the superficial location of the facial nerve and  possibility of facial nerve damage during flap elevation  [68] (Fig. 46.27).   The Blair incision is an S-shaped incision that starts from  the preauricular region and extends in the neck. The major  disadvantage of the Blair incision is a visible scar in the neck  that may cause facial or cervical disfigurement causing  patients dissatisfaction [70].   The standard incision is a modified Blair incision  (Fig. 46.28) wherein the skin incision is placed in a preau-  ricular crease and doesn’t extend beyond the level of the root  of the helix. It extends inferiorly around the ear lobule over  the mastoid tip. It gently curves down along the sternocleido-  mastoid muscle and then slightly forward in a natural crease  in the upper neck [71].   A facelift incision can be used to avoid the hollowing  after parotidectomy, and the defect can be filled with SMAS  advancement flap (Bananno and Casson [72], 1992).  However, the SMAS-lifting technique is not a routine proce-  dure for many surgeons [73].   Rai A et al. [74] advocated use of posterior belly of the  diagastric muscle flap (PBDMF) for reconstruction of the  surgical defect after superficial parotidectomy. PBDM inserts  very close to stylomastoid foramen, and it is considered as an    important landmark in the identification of facial nerve main  trunk. The harvesting and dissection of PBDMF becomes  easier as it lies in the surgical site, and no extra incision is  required to harvest it. It can be used in thin and young  patients with good esthetic results.    This has been previously described in the section on applied  anatomy of the parotid gland.    The selection of type of procedure for surgical management  of parotid tumors depends on the site, size and clinicohisto-  pathologic features. The various procedures are described  briefly as under:   This technique is used for management of a small tumor in  the tail of the parotid gland less than 3.5 cm. Due to small  tumor size, most of the functional gland along with the duct  can be preserved.   After marking the incision, infiltration is usually done with  Saline Plus 1 in 200,000 parts adrenaline instead of ligno-  caine with adrenaline to avoid blocking the facial nerve  fibers. In case lignocaine is used, care should be taken to  avoid deep injections. Care should be taken to avoid extend-  ing the incision too far posterior beneath the ear lobe to avoid  persistent edema [75].   The incision in the neck crease is deepened to raise a flap  in the subplatysmal plane (Fig. 46.29). The greater auricular  nerve is identified and preserved. It branches over the surface  of the gland where two or more branches should be followed  and then divided.   Once the deep fascia has been identified, rest of the wound  is deepened to this level and skin reflected forward from it.  At the zygomatic bone, some subcutaneous fat should be left  on the fascia to avoid damaging the branches of facial nerve  which lie more superficially as they emerge from the upper  part of the parotid. The main trunk of the nerve is found by  first separating the lower pole of the gland from the anterior  border of the sternomastoid and then from the mastoid pro-  cess and the cartilaginous part of the external auditory  meatus (Fig. 46.30). The wound is deepened anterior to the  margin of the sternomastoid, and the lower pole is dissected  free as far forward as the external jugular, uncovering the  posterior belly of the digastric muscle. The vein should not  be divided and tied at this stage because this will increase the  venous engorgement of the parotid and the ooze from its  divided tissues.   Neither should the lower pole be raised further forward  because the branches of the facial nerve often pass superfi-  cial to the vein and emerge from the gland anterior to it. The  parotid is retracted forward as the dissection proceeds and    Fig. 46.29 Flap raised in the sub platysmal plane exposing the super-  ficial surface of tumor    the pointed, lower extremity of the tragal cartilage (pointer)  will be uncovered. Where possible, the edge of the fascia  should be raised and the underlying tissue separated by blunt  dissection until the nerve is seen as white cords some 2-3 mm  thick.    The stylomastoid branch of the posterior auricular artery  passes superficial to the nerve to enter the stylomastoid fora-  men. Damage to this vessel should be avoided as bleeding  may hamper vision, and also it supplies a nutrient branch to  the nerve. The curved mosquito forceps are used for dissec-  tion by opening the blades a little at a time to stretch the tis-  sues and raise it, so as to lift the gland substance off the  surface of the nerve, and then expose it by cutting through  the gland with scissors. At all times when a cut is made, the  adjacent nerve must be seen clearly.   ally within the parotid, and just below the neck of the con-  dyle, it splits into an upper temporofacial and a lower  cervicofacial division. Follow the lower division first, and  trace the cervical or the marginal mandibular branch anteri-  orly to a point in front of the parotid to mobilize the lower  pole completely. Then by progressing upward, branch by  branch further mobilization can be achieved (Fig. 46.31).  Some tissue should always be left on the tumor to ensure  complete removal.  In general, the nerves pass superficial to the retromandibular  vein, but some may pass deep to it. Careful mobilization of  both nerve and vein with division and ligation of the latter is  necessary. Tiny vessels should be sealed with bipolar dia-  thermy avoiding damage to adjacent nerves.   [76]  This is superficial parotidectomy where gland function is  preserved by preservation of the Stenson’s duct. If the duct is  superficial to the buccal branch, its preservation is contrain-  dicated as it will obstruct the surgical procedure. After rais-  ing the skin flap and exposing the parotid gland, the duct is  identified passing on the masseter muscle. Stenson’s duct is  located; dissection and ligation of the duct are avoided unless  it is located superficial to the buccal branches of the facial  nerve. Rest of the procedure is similar to superficial  parotidectomy.   e It avoids the influence of subsequent gland atrophy on  facial contour.   This is similar to local excision of parotid gland. Maximum  healthy tissue is left behind without compromising on the  clearance. The advantage of this procedure over superficial  parotidectomy is relatively low incidence of Frey’s syn-  drome. The reported incidence of this complication is 4.8%  [77]. In addition, better gland function is preserved due to  more parenchyma that is left back [78].   It is a transoral approach used in removal of few benign  tumors of the deep lobe, which are easily visible displacing  the superior portion of the tonsil and soft palate medially. An  incision is made with cautery or knife over the most promi-  nent aspect of the swelling in the tonsil and palate area,  extending above and below the apparent location of the  tumor. The constrictor muscle is identified, and dissection is  continued through thinned constrictor muscle by dividing it  above and below the tumor. Pressure on the neck often assists  in removal of the tumor. Fascial connections from the tumor  into the adjacent bed are removed with blunt dissection, and  the tumor is delivered into the mouth. Any vascular connec-  tions to the tumor should be cauterized, and meticulous  hemostasis should be achieved. The superior and inferior  portions of the wound are closed with interrupted sutures.  The middle portion of the wound is left open to heal  secondarily.    46.8.3.6 Total Parotidectomy with or Without  Facial Nerve Preservation  It is usually indicated in tumors affecting the deep lobe. A  neoplasm of the deep part of the parotid enters the soft palate  through the interval between the styloid process and the back  of the mandible and is often of dumbbell shape with the isth-  mus lying in this gap. After raising a skin flap, the facial  nerve is identified and dissected out leaving a layer of glan-  dular tissue on it. An access osteotomy either in the form of  vertical subsigmoid or mandibular body distal to the mental  foramen is used to open up the interval between the mandible  and the styloid process through which the tumor has passed.  The stylohyoid muscle may be divided close to the styloid  process and turned forward. The external carotid artery will  be encountered emerging above the muscles and should be  divided. The origin of the facial artery should be identified to  check the identity of the vessel.  As the parotid gland and the tumor are freed, it may be raised up  between the two nerve bundles or below both bundles. Next  entry is made intraorally over the tumor, and under direct vision  tissues are divided to deliver the mass. Care is taken to avoid  damaging the internal jugular vein and internal carotid artery  which lie deep to styloid process. Following removal of the  mass, the wound is irrigated, and the oral tissues closed with  care using resorbable suture. The drapes are replaced over the  mouth, gloves changed, and the mandibular fragments fixed  together and the wound closed in the normal way.   The advantages of this flap are that exposure of the gland is  sufficient and the dissection is easy to perform. There is no  donor-site morbidity, minimum additional operating time,  and no extra cost. It seems to decrease the incidence of Frey’s  syndrome. The speed of the recovery of the facial nerve has  been highlighted in the literature. It is more satisfactory from  the patient’s point of view.   and Temporoparotidectomy [80]  Parotidomandibulectomy is indicated where there is invasion  of the mandible by a malignant neoplasm.  In temporoparatidectomy, small-scale resection of the exter-  nal auditory canal may be included with the excision of the    pinna and overlying skin of the parotid where these struc-  tures are involved. The deficiency may be made good with a  deltopectoral or other suitable flap.    In the case of lymph node metastasis as stated in surgical  pathology, neck dissection can be done in continuity with  parotidectomy by increasing the neck skin crease incision  and clearing the lymphatic structures.    ¢ Facial paresis or paralysis often results from poor tech-  nique and failure to preserve small nerve branches.   ¢ Bleeding and hematoma formation, which can signifi-  cantly compromise the airway.    Small tumors confined to the gland are treated by sialadenec-  tomy, and tumors spreading beyond the confines of the gland  are treated with a wider en bloc excision, which may include  resection of the floor of mouth and mandible depending on  extent of tumor. The neurotropic tumors might involve the  lingual, hypoglossal, mylohyoid, and marginal mandibular  nerve leading to a perineurial spread which can be confirmed  on frozen section. Thickening and nodularity of the nerves  may indicate perineural involvement [81].    For submandibular sialadenectomy, a skin crease incision  below 3 cm from the lower border of mandible is taken to  avoid damaging the marginal mandibular nerve which loops  below the lower border of the mandible (Fig. 46.32).   For simple excision of the sublingual gland, an incision is  made in the floor of the mouth lateral to the submandibular    duct taking care to limit it up to premolar region, as at the  molar region, there is a chance to damage the lingual nerve.  When sublingual gland excision is necessary for a tumor, it  should be removed with a wide margin including a rim resec-  tion of the mandible.    After making an incision in the neck crease, skin flap is  raised in the subplatysmal plane (Fig. 46.33). The capsule of  the gland should be left intact when the sialadenectomy is  being done for a tumor, which might compromise the  marginal mandibular nerve. The facial artery and nerve are  identified as close to the gland as possible. After transection,  they are elevated superiorly to identify and reflect the mar-  ginal mandibular nerve. Nowadays the facial artery is spared  during surgery to allow free flap anastomosis during onco-  surgeries (Fig. 46.34). The investing fascia is then divided at  the lower border of mandible, and the gland is delivered out  from between the anterior and posterior bellies of the digas-  tric muscle. Anteriorly the gland is separated from the mylo-  hyoid muscle, and lingual nerve, hypoglossal nerve, and  Wharton’s duct are identified. The lingual nerve shares the  same facial sheath as the gland at the upper pole. This attach-  ment of the lingual nerve to the gland represents its parasym-  pathetic supply. The Wharton’s duct is inferior to lingual  nerve and is often surrounded by sublingual glands. As fascia  and gland are mobilized upward from the surface of the hyo-  glossus, the hypoglossal nerve is identified more inferiorly. It  is accompanied by ranine vein. Posteriorly the angular tract    of fascia has to be cut with scissors to allow the gland in its  fascial envelope to be drawn down without grasping the  gland with instruments. Where necessary the upper pole may  be mobilized via the mouth. An assistant can then depress the  gland toward the submandibular wound to enable the opera-  tion to be concluded.   The duct and the branch of the lingual nerve supplying the  submandibular gland are ligated and transected. The duct is  divided close behind the papilla. During excision for inflam-  matory disease, the nerve is always separated from the gland  with knife or scissors. However, if the nerve appears to be  involved in a tumor, it is sectioned in front of and behind the  gland and the cut ends sutured. The wound is closed in layers  with drainage in the usual way.    Surgical resection of minor salivary gland tumors depends  on the site of origin and extent of disease. This may range  from a wide local excision of localized low-grade tumors to  more radical excision, including marginal or segmental man-  dibulectomy and/or partial or total resection of the hard or  soft palate, partial or total maxillectomy, infratemporal fossa  dissection, and/or anterior craniofacial resection for larger  and/or high-grade tumors. The V2 and V3 divisions of the  trigeminal nerve are at potential risk for perineural spread of  minor salivary gland malignancy and may facilitate an early  skull base metastasis. Resection of the cranial base may be  required in some cases to eradicate the tumor and obtain  negative surgical margins [81].    Small pleomorphic adenomas on the palate can cause  pressure resorption of the bone but do not cause true bony  invasion. They are managed by local excision along with  the periosteum. In the case of involvement of greater pala-  tine foramen area, the lesion is freed until it can be drawn  down, and the vessels clamped and cauterized under direct  vision. If not, the vessel retracts into the canal and causes  irritating bleeding. The wound is left to granulate  secondarily.    Low-grade mucoepidermoid carcinomas may be treated by  the excision of a full-thickness disk of palate, including pala-  tal and alveolar bone. Nasal and oral mucous membranes are  sutured together around the defect in the soft palate. Primary  reconstruction is avoided and an obturator is used instead  (Fig. 46.35a, b).    Spread along the perineurial tissues makes an inadequate surgi-  cal margin very likely after surgical management of ACC. A  combination of surgery and radiotherapy is best. Surgical exci-  sion should be generous. Hemimaxillectomy including the  orbital floor is a minimum, unless there is very good evidence  that less will be sufficient. Where the soft palate and pterygoid  region are involved, extended maxillectomy approach is essen-  tial to ensure adequate excision under direct vision.    A primary excision with a margin of normal adjacent tissue  can be used, but if there is any doubt, it can be preceded by  a biopsy. Re-operation following incomplete extirpation    Fig. 46.35 (a) CT scan showing mucoepidermoid carcinoma of palate (red arrow). (b) Surgical excision of tumor using standard Weber-Ferguson    could mean the unnecessary sacrifice of tissue to ensure an  adequate margin on the second occasion. Clinically aggres-  sive neoplasms must be biopsied, since adequate treatment  may involve radiotherapy and full-thickness excision and  repair.   More aggressive tumors affecting the palatal salivary  glands are managed by partial maxillectomy or total maxil-  lectomy or extended maxillectomy based on the extent of  disease.    e A hematoma may develop in the dead space after gland  excision. It can be avoided by meticulous hemostasis and  placement of suction drain to clear out any collection. In  case a hematoma develops, it can be aspirated or sucked  under aseptic precautions. However, it may not be com-  pletely effective. The patient can be just put on good anti-  biotic coverage, and it will resolve without getting  infected.   e Trismus occurs due to masseter muscle spasm or inflam-  mation in the TMJ. It generally resolves spontaneously  and hence should be just managed symptomatically.   e Salivary fistula occurs uncommonly due to discontinuity  between the residual salivary gland parenchyma and the  salivary duct. In majority of cases, the problem is self-  limiting. Management includes repeated aspiration, pres-  sure dressings, wound care, an antisialogogue medication  (glycopyrrolate), and patience.   ¢ Facial nerve dysfunction results from traction injury to  the facial nerve (neuropraxia) during dissection in parotid  surgery. Complete recovery within a few months can be  expected if nerve integrity has been maintained. In case  the nerve is transected, it should be followed by immedi-  ate nerve grafting repair.   e Auriculotemporal syndrome of Frey is also called gusta-  tory sweating. It manifests as flushing and sweating of the  skin of upper cheek, temporal region, and forehead coin-  cident with eating and smelling of food. Following dam-  age to the auriculotemporal nerve or to communicating  branches to the facial nerve, secretomotor parasympa-  thetic nerves from the otic ganglion and also sympathetic  fibers to the sweat glands traveling in the same nerve are  divided. Following regeneration, fibers from otic ganglion  come to supply the sweat glands. Minor’s starch-iodine  test is used for diagnosis [78]. It can be managed by sim-  ple treatment of antiperspirant application; 1% local  application of glycopyrrolate is effective. The only effec-  tive cure is to divide the parasympathetic fibers from the  glossopharyngeal nerve.    Sensory abnormalities associated with greater auricular  nerve sacrifice, reflect as sensory deficit in the lower third of    pinna including earlobe as well as adjacent preauricular and  postauricular skin.    Robotic sialadenectomy of the submandibular gland has  been done via a modified face lift approach. Virgilio et al.  performed robotic sialadenectomy of the submandibular  gland in five patients (two patients each with sialolithiasis  and pleomorphic adenoma and one patient of ranula) with  success. They used three robotic arms, two operative arms,  and a facedown 30° endoscopic arm. The operative left arm  is equipped with Maryland forceps and right arm with har-  monic scalpel.    Salivary gland pathologies may be neoplastic, non-neoplastic,  inflammatory, or non-inflammatory. Early surgical interven-  tion after a good clinical, radiological, and histopathological  diagnosis is need of an hour to minimize the postoperative  complications. Early diagnosis and management with recent  advanced technologies is the key factor in achieving excel-  lent prognosis of the disease.    Acknowledgment Author wishes to thank Dr. Anshul Rai for  Figs. 46.3, 46.4, 46.9, 46.13, 46.17a, b, and 46.20.   Author wishes to thank Dr. Kedar Saraf, Professor, Dept. of OMDR,  SMBT Institute of Dental Sciences, Sangamner, Maharashtra, for  Figs. 46.1 1a, b, and 46.12.    1. Saunders PR, Macpherson DW. Acute suppurative parotitis: a for-  gotten cause of upper airway obstruction. Oral Surg Oral Med Oral  Pathol. 1991;72:412-4.   2. Hollinshead WH. The face. Anatomy for surgeons: Vol I. The head  and neck. 3rd ed. Philadelphia: Harper and Row Publishers; 1982.  p. 291-324. Chapter 6.   3. Cawson R, Gleeson M. Anatomy and physiology of the salivary  glands. In: Gleeson M, editor. 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England: Wolfe Medical. p. 117-33.   81. Hanna EY, Suen JY. Malignant tumors of the salivary glands. In:  Myers EN, Suen JY, Myers JN, Hanna EY, editors. Cancer of the  head and neck. 4th ed. Saunders; 2003. Chapter 21, p. 475-510.   82. Seward GR. Nodular enlargement of a salivary gland. In: Moore  J, editor. Surgery of the mouth and jaws. London: Blackwell  Scientific; 1985. Chapter 38, p. 676-99.   83. Hanna EY, Suen JY. The Parotid neoplasm. Section 22.  Controversies in otolaryngology. In: Pensak ML, editor. New York:  Publication Thieme; 2001. Chapter 66, p. 348-54.   84. Virgilio DA, et al. Robotic sialoadenectomy of the submandibular  gland via a modified face-lift approach. Int J Oral Maxillofac Surg.  2012;41:1325-9.    Barnes L, Eveson JW, Reichart P, Sidransky D. World Health  Organization classification of tumours. Pathology and genetics of  head and neck tumours. vol. 9. Lyon: IARC; 2005.   Kennedy RA. WHO is in and WHO is out of the mouth, salivary glands,  and jaws sections of the 4th edition of the WHO classification of  head and neck tumours. Br J Oral Maxillofac Surg. 2018;56(2):90-S.   McGurk M, Combes J. Controversies in the management of salivary  gland disease. 2nd ed. Oxford University Press; 2013.    Open Access _ This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.  org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropri-  ate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.    The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in    a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.   Salivary gland diseases have been described in the literature  for centuries. From the time of Hippocrates to the descriptions  of parotid tumours in the sixteenth century and the anatomical  descriptions of the ductal systems of the major salivary glands  in the seventeenth century, we have assimilated knowledge of  anatomy and pathology of these glands [1].   The conventional approach to infections of the salivary  glands is medical management, occasional expression of the  stone through the papilla, marsupialisation of the duct fol-  lowing removal of sialolith. Failing all, removal of the  involved gland [2].   Minimally invasive surgery especially those in which  endoscopes are utilized has gradually become popular over  the last three decades. As a whole, the trend in surgery is to  improve function and hasten recovery. To achieve these ends,  a combination of technology and smaller incisions has been  crucial. Hence there is an increasing interest to manage sali-  vary gland diseases endoscopically [3].   Sialendoscopy is the endoscopic management of obstruc-  tive salivary ductal disease and has rapidly become the pro-  cedure of choice for such conditions.    Salivary gland diseases can broadly be classified into ductal  and parenchymal disorders.    Electronic Supplementary Material The online version of this chap-  ter (https://doi.org/10.1007/978-98 1-15-1346-6_47) contains supple-  mentary material, which is available to authorized users.   Department of Oral and Maxillofacial Surgery, Rangadore  Memorial Hospital, Apollo Hospitals,    © The Association of Oral and Maxillofacial Surgeons of India 2021    Some conditions, such as Sjégren’s syndrome and juve-  nile recurrent parotitis, tend to have an overlapping compo-  nent and thus are difficult to segregate.   e Strictures within the duct or at the punctum,  e Presence of mucous plugs, and    The majority of obstructive salivary gland disease can be  attributed to the presence of stones or sialoliths. Almost  60-70% of reported obstructive salivary disease comprises  of sialolithiasis [4], which occurs in about 1.2% of the popu-  lation. Amongst the major salivary glands, the submandibu-  lar is most affected (87%) , then the parotid (10%), and the  sublingual (3%) to a much lesser extent [5].   Although sialolithiasis has been reported as the most  common cause of salivary ductal obstructions, strictures,  mucous plugs and the rare foreign body can cause significant  obstruction to ductal flow.    Sialendoscopy is a minimally invasive technique which  makes use of miniature endoscopes to diagnose and treat  salivary gland pathologies, including sialolithiasis, sialade-  nitis and strictures.   It is fast becoming the investigating procedure of choice  for such conditions. Sialendoscopy has grown as a  subspeciality in the last three decades, since the first attempts  to retrieve salivary stones endoscopically were carried out. It  is slowly gaining popularity and awareness in the last decade  and a half.    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1-15-1346-6_47    It took a few centuries, after the discovery of the ductal sys-  tems, for the first endoscopy to be reported. In 1990,  Konigsberger et al. reported the first successful salivary  endoscopy using a 0.8-mm flexible endoscope. Katz removed  a stone with a flexible scope using blind passage of a basket  in 1991, and for over a decade, both Nahlieli et al. and  Marchal described various types of sialendoscopy instru-  ments and approaches [3].   The last decade and a half has witnessed significant devel-  opment of minimally invasive techniques for diagnosing and  treating salivary ductal obstructions. Like with other surgical  fields, this has led to a paradigm shift from open procedures  to minimally invasive and endoscopic techniques with the  emphasis on gland preservation and restoration of function.  The miniaturization of endoscopes and advancing technol-  ogy have made exploration and visualization of salivary duc-  tal system possible using sialendoscopes [4].   As mentioned previously, sialolithiasis is the most common  obstructive condition affecting the salivary duct and there-  fore is where sialendoscopic/sialendoscopy-assisted retrieval  of sialoliths is most indicated.   Ductal strictures which may be secondary to calculi or those  at the papilla opening can be very effectively treated by serial  dilatation with sialendoscopes of increasing diameter [4].   Juvenile recurrent parotitis (JRP) is an inflammatory con-  dition affecting the parotid gland and is the second most  common condition in children after mumps [6, 7]. The con-  dition affects the paediatric population primarily especially  the ages between 3 and 6 years and occasionally persists in  adolescence [8]. As the cause is unknown, management has  generally been conservative. Anatomical aberrations, such as  kinks in the duct, dehydration and possible ascending bacte-  rial infection, have been hypothesised as causes.   Dilatation and lavage as a consequence of performing  sialendoscopy has provided relief from symptoms and reduc-  tion in the frequency of attacks, even though the mechanism  is not fully understood. This condition has a tendency of  spontaneous cessation at puberty.   Although in Sjogren’s syndrome, where the parenchyma  of the parotid gland is primarily affected, there is also an  associated ductal pathology, namely, strictures. Here too  dilatation via sialendoscopy can provide symptomatic  relief.   Acute inflammation of salivary glands and ducts is a con-  traindication to performing sialendoscopy. The duct is essen-  tially a condensation of surrounding epithelium and not a rigid    structure. In such an inflamed state, the risk of creating a false  passage or perforating the duct is significantly higher [4].   Management in such situations is conservative, mainly  with the use of appropriate antibiotics and analgesics, incision  and drainage of a collection, and removal of cause, such as a  sialolith, if easily visible or accessible, to allow acute symp-  toms to settle before a formal sialendoscopy is carried out.   Trismus is a relative contraindication to performing sialen-  doscopy, as naturally, reduction in mouth opening makes it  both difficult to introduce and manoeuvre the scopes.   A simple ultrasound in the hands of an experienced sonolo-  gist usually provides adequate information prior to sialen-  doscopy. It is a non-invasive, economical investigation which  can determine the presence and size of sialoliths, strictures,  dilatation or fibrosis of the duct. Alternatively a CT scan can  be considered to achieve the same result.   MR sialograms are particularly useful in identifying stric-  tures or areas of stenosis. However, like conventional sialogra-  phy the papilla needs to be dilated and cannulated to inject the  dye. In the hands of an inexperienced operator, damage to  papilla might make performing sialendoscopy impossible.    The sialendoscope can be divided very simply into two sys-  tems: the Marchal All-in-one (Fig. 47.1) and the Modular  system (Fig. 47.2).   As the name suggests, the all-in-one has an irrigation  port, a working channel through which various instruments  can be introduced, and fibre optics in the same unit. This  scope serves as both diagnostic and as an interventional tool.   The modular sialoendoscope consists only of a telescope,  attached fibre-optic cable and an eyepiece. Interchangeable  sheaths of various diameters are available which fit onto the  basic telescope [6]. This scope with the appropriate sheaths  can be used for both diagnostic and interventional purposes.   The sheaths used in the modular system make it rigid and  unfortunately also bulky; thus significant dilatation of the  papilla is required to introduce the scope [6].   Unlike other endoscopes, sialendoscopes come with only  a zero-degree viewing angle. The all-in-one is semirigid,  with a 5—15-degree angulation at the tip to facilitate manoeu-  vrability especially while exploring branches of the duct.   Diagnostic scopes come with only an irrigation port,  whereas a working channel is also provided in therapeutic  scopes to introduce instruments such as wire baskets and  graspers for entrapping stones, balloons for stricture dilation    and a holmium laser fibre or a micro drill to fragment sialo-  liths [6].   Diameter of available scopes range from 0.9 to 1.6 mm,  the smallest purely diagnostic and others having various  sizes of the working channel to allow certain instruments  only. This is a disadvantage of the all-in-one system in that  the entire scope has to be changed if a larger instrument is  required, whereas in the modular only the sheath can be  changed [6].   Preliminary instruments, those that are used to dilate  the papilla to facilitate the introduction of the scope, are  also available. These include two types of dilators, papil-  lotomy scissors, guide wires and hollow dilators [6]    Association of Oral and Maxillofacial Surgeons of India  Fig. 47.3 Armamentarium. (1) Conic dilators, (2) Lacrimal probes, (3)  Sialendoscopes, (4) Guide wire, (5) Sheaths for Modular sialendo-  scope, (6) hollow dilators, (7) vascular forceps, (8) papillotomy  SCISSOrs    Anaesthetic of choice depends on the clinical and radiologically  findings and the anticipated difficulty of the procedure. Local  anaesthetic, with or without sedation, is usually adequate for a  diagnostic procedure. In cases where sialolith retrieval is  planned, either endoscopically or with a combined approach,  general anaesthetic is usually preferable. Antisecretory agents  like atropine and glycopyrrolate are avoided [6].    Patient is placed supine with head fixed on a head rest and  turned towards the surgeon. Shoulder extension is prefera-  ble. The monitor is placed opposite the surgeon. The assis-  tant is next to the surgeon [6].    The Wharton’s duct punctum is comparatively more difficult  to locate given the position is quite variable. There may even  be a ‘hood’ of tissue obscuring the opening. In such situa-  tions, local anaesthetic can be infiltrated around the area  which stiffens the opening, thereby aiding in location.  Occasionally an incision might need to be placed on the floor  of the mouth accompanied by minimal dissection to locate  the duct. The Stensen’s duct opening is far easier to identify.  It is located on the buccal mucosa opposite upper second  molar. Once the punctum is identified, the opening is serially  dilated with conical dilator and probes of various sizes [6].    Once the punctum is adequately dilated, the appropriate  sialendoscope is introduced into the duct. The duct is  normally a collapsed structure, and irrigation fluid is  required to keep the lumen open to visualise the duct and  to advance the scope (Fig. 47.4). Normal saline is the  preferred choice of irrigant solution and is diluted with  local anaesthetic if the patient is awake for the  procedure.   The irrigant also serves an additional purpose as this also  performs lavage of the duct, thereby washing out debris and  mucous plugs which might be accumulated [6].   The endoscope is slowly and gently passed from the  punctum till branches are identified and explored if pos-  sible. This point of division of the duct is known as the  hilum and is considered the end point of sialendoscopy.  Alternatively, the presence of pathology such as a sialolith  or stricture may prevent complete exploration of the duct  (Figs. 47.5 and 47.6). It is important to note that once the  pathology has been treated, the entire duct must be  explored so as to ensure there are no further causes of  obstruction, including the withdrawal of the scope under  vision [6].   As the scope is guided through the primary and secondary  ducts, the colour and texture of the mucosa are noted which  are an indicator of the presence of inflammation. In relation  to sialoliths, the size, shape and position need to be assessed  as these will determine the method of retrieval [6].   Between the submandibular and the parotid duct, the  Stensen’s duct is comparatively more difficult to navigate  due to the presence of the masseteric bend.    Indications for a diagnostic procedure include clinical symp-  toms, yet an unremarkable ultrasound and stricture at the  papilla opening, to assess size and position of sialoliths.  Diagnostic sialendoscopy is a low morbidity, minimally  invasive technique, which becomes the investigational pro-  cedure of choice for salivary duct pathologies in all age    groups. Sialendoscopy has the advantage of offering a real-  time ductal view. Diagnostic endoscopy is occasionally ther-  apeutic, in minor obstructions caused by mucous plugs  which can be relieved by lavage.   Interventional sialendoscopy makes use of a wide array of  armamentarium including wire baskets (Fig. 47.7), balloon  catheters and holmium laser to assist in sialolith retrieval  (Fig. 47.8).   Sialoliths with sizes ranging between 3 and 4 mm are  amenable for endoscopic retrieval. Here they may be    entrapped and retrieved by use of a wire basket or dragged to  the punctual opening where a small incision is placed to  facilitate removal.   Larger stones require a combined approach, whereby the  position of the sialolith is identified and marked endoscopi-  cally and retrieved with an open surgical approach. The open  approaches for submandibular sialoliths may be as small as a  papillotomy or an extensive dissection of the floor of the  mouth. The lingual nerve and iatrogenic ranula formation are  important considerations when operating in this region.  Large parotid stones require a SMAS flap, for the identifica-  tion and protection of facial nerve branches and the duct, as  well as reconstruction post-retrieval. Sialocele formation is  an important consideration.   Hollow bougies of increasing diameter can threaded over  a guide wire to widen strictures at the papillae. Balloons are  another means of treating ductal strictures and once intro-  duced through the working channel of the sialendoscope are  inflated to dilate narrowed areas of the duct wall.   Stents are placed to maintain the patency of the duct and  also to allow an incised duct to heal over with the aim of  preventing stenosis. These stents are generally kept in place  for up to 3 weeks. The authors have devised a salivary stent  (Moorthy-Bachalli stent), made of polyurethane. These  stents are available in sizes ranging from 3.5 French (diam-  eter, | Fr = 0.3 mm) to 8 French and lengths from 5 to 7 cm  with markings every centimetre. The stents also have a flange  with prefabricated suture holes to facilitate suturing to the  surrounding mucosa. An Ethilon 4-0 suture is preferred by  the authors.    Like any other surgical procedure, open or endoscopic,  sialendoscopy has its fair share of complications  (Table 47.1).   In case of floor of mouth or cheek oedema,  then abort    When compared to other medical specialities, particularly  otorhinolaryngologists, maxillofacial surgery is still in a  primitive stage as far as the use of endovision is concerned.  Hopefully an interest in areas like endoscopic management  of salivary gland and temporomandibular joint diseases will  narrow this gap.   Sialendoscopy is still in its infancy, in many parts of the  world. Despite the challenges, growing awareness and the  added attraction of minimally invasive surgery is steadily  making it a popular choice for managing salivary ductal  disease.    1.Marchal F. Sialendoscopy: the endoscopic approach to salivary  gland ductal pathologies. Endo Press: Tuttlingen; 2012. pp 8.    2. Al-Abri R, Marchal F. New era of endoscopic approach for sialoli-  thiasis: sialendoscopy. SQU Med J. 2010;10(3):382-7. Epub 14th  Nov 10.   3. Erkul E, Gillespie MB. Sialendoscopy for non-stone disorders.  Laryngoscope Investig Otolaryngol. 2016;1:140—5.   4. Singh PP, Gupta N, Goyal A, Tomar S. Interventional sialendos-  copy for parotid ductal calculi: our preliminary experience. Indian J  Otolaryngol Head Neck Surg. 2012;64(3):252-6.   5. Kopeé T, Szyfte W, Wierzbicka M. Sialoendoscopy and combined  approach for the management of salivary gland stones. Eur Arch  Otorhinolaryngol. 2013;270:219-23.   6.Singh PP, Gupta V. Sialendoscopy: introduction, indications and  technique. Indian J Otolaryngol Head Neck Surg. 2014;66(1):74-8.   7. Harold D. Baurmash: chronic recurrent parotitis: a closer look at  its origin, diagnosis, and management. J Oral Maxillofac Surg.  2004;62:1010-8.   8. Canzi P, Occhini A, Pagella F, Marchal F, Benazzo M. Sialendoscopy  in juvenile recurrent parotitis: a review of the literature. Acta  Otorhinolaryngol Ital. 2013;33:367-73.    Open Access This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.  org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropri-  ate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.   The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in  a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.   Maxillofacial injuries are common in polytrauma patients, and  spectrum can be minor to life-threatening injuries. Primary  assessment and management can be very important. They can  involve facial soft tissues, facial bones, or both. Maxillofacial  injuries can be due to various causes including road traffic  accidents, assaults, and fall from height, industrial injuries,  animal bites, sports injuries, burns, and war injuries. Life-  threatening maxillofacial injuries can complicate the initial  management of a trauma patient due to presence of concomi-  tant injuries to airway, head, or cervical spine.   The mechanism for this injury is exemplified by an  unbelted automobile passenger who is thrown into the wind-  shield and dashboard. Trauma to midface can produce frac-  tures and dislocations that compromise the nasopharynx and  oropharynx. Facial fractures can be associated with hemor-  rhage, increased secretion, and dislodged teeth. Fractures of  mandible, especially bilateral body fractures, can cause loss  of normal airway and structural support. Airway obstruction  can result if the patient is in supine position.   The term “golden hour” has to be kept in mind while han-  dling the trauma patient which indicates that the injured  patient has | h (60 min) from the time of injury to receive  definitive care. After that there will be significant increase in  the morbidity and mortality of the patient. “Chances of sur-  vival of the critically injured patient will largerly determine  after the first hour’ [3].    Electronic Supplementary Material The online version of this chap-  ter (https://doi.org/10.1007/978-98 1-15-1346-6_48) contains supple-  mentary material, which is available to authorized users.    S. Saigal   Department of Anaesthesiology, AIMS Bhopal,  Bhopal, Madhya Pradesh, India    M. M. Khan  Department of Burns and Plastic Surgery, AIIMS Bhopal,  Bhopal, Madhya Pradesh, India    © The Association of Oral and Maxillofacial Surgeons of India 2021    Sorting of patients based on their need for treatment and the  available resources to provide the treatment is triage. This  sorting may be carried out by the paramedic team at the acci-  dent scene or receiving hospital who decides what level of  care is required. It may be based on which patients need  immediate, lifesaving interventions, which can wait and  which are, in fact, beyond saving. Depending on the urgency  of treatment required, maxillofacial injuries can be broadly  placed into one of four groups (Table 48.1).   Appropriate triage and prompt evaluation, using the Advanced  Trauma Life Support (ATLS) system, benefit patients [5].    Box 48.1 Step-by-Step Management of a Trauma Patient  in Emergency Unit    Patient arrival at hospital  Primary Survey (ABCDE) and Resuscitation  Pulse oximetry, ECG, BP,  —____—_  Blood results, CXR, Pelvic X-ray  Reassessment of ABCDE    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1-15-1346-6_48   / Patient stable but urgent management  needed (cranial fractures with open dura,  contaminated wounds, and open fractures)    Best motor response (level of central nervous system function)  Best verbal response (ability of CNS to integrate information)  Eye opening (brainstem activity)    The primary survey is a rapid, reproducible physical exami-  nation to evaluate every trauma patient and is designed to  diagnose and treat immediately life-threatening conditions  first. All patients are evaluated for physiologic or anatomic  derangements that could lead to early mortality and morbid-  ity. Treatment of problems identified during the primary sur-  vey begins without delay, before the survey is completed.    Patient monitoring (pulse oximetry, electrocardiogram  (ECG), blood pressure (BP), blood results, chest and pelvic  radiographs) should run in parallel with the primary survey.  Team approach is crucial for primary survey.    Airway assessment is first and foremost priority of primary  survey. Patients with maxillofacial and head injuries are at  high risk of compromised airway.   — Foreign bodies in the form of avulsed teeth or  dentures    The chin lift or jaw-thrust maneuver is recommended  to achieve patency of airway. The patient’s head and  neck should not be hyperextended, hyperflexed, or  rotated to establish and maintain the airway. There may  be associated cervical spine injury; all the cases are  treated as they are having cervical spine injury unless  diagnosed otherwise. Hence, cervical spine stabilization  should be done.    48.3.2 Airway and Ventilatory Problems  in Maxillofacial Trauma (Please Refer  Chap. 7 of this book)    Early preventable deaths from airway problem after maxil-  lofacial trauma often result from:   ¢ Lack of backup or alternative airway plan in the setting of  failed intubation attempts    Airway compromise may be sudden and complete, insidious  and partial, and/or progressive and recurrent. The early sign  of airway or ventilator compromise is tachypnea or inability  to speak words or sentences. “Talking patient” provides reas-  surance for that period of time that the airway is patent and  not compromised. Failure to respond or an inappropriate  response suggests an altered level of consciousness, airway  and ventilator compromise, or both. Patient with the altered  level of consciousness is at particular risk for airway com-  promise and aspiration, so he requires definite airway.    1. Observe the patient for agitation and obtundation, suggest  hypercarbia, and cyanosis indicates hypoxemia due to  inadequate oxygenation which can be identified by  inspection of nail beds and circum-oral skin. However,  cyanosis is a late finding of hypoxia. Pulse oximetry is  used early in the airway assessment, to detect inadequate  oxygenation prior to development of cyanosis. Look for  retractions and use of accessory muscles of ventilation  that, when present, provide additional evidence of airway  compromise.   2. Listen for abnormal, noisy sound breathing which is usu-  ally snoring, gurgling, and crowing sound (stridor) and  can be associated with partial obstruction of the pharynx  or larynx. Hoarseness (dysphonia) implies functional,  laryngeal obstruction.   3. Feel for location of trachea, and quickly determine  whether it is in the midline position.   4. Evaluate patient behavior. Abusive and belligerent patient  may in fact have hypoxia and should not be presumed to  be intoxicated (suggestive of hypoxia, then only presume  intoxication).    To assess airway patency and adequate ventilation quickly and  accurately, pulse oximetry and end-tidal CO, measurement are  essential. There are some measures to improve the oxygen-  ation including airway maintenance techniques, definitive air-  way measures, or surgical airways. Because abovementioned  measures include some movement of the neck, it is important  to maintain cervical spine protection in all patients of trauma.    High-flow oxygen is required both before and immedi-  ately after airway management measures are instituted. A  rigid suction device is essential and should be readily avail-  able. Nasal route for endotracheal route should not be chosen  in patients with facial injury and midface injury. Patients  who are wearing helmet and require airway management  need their head and neck held in a neutral position. For this  two-person procedure, one person provides manual inline  stabilization from below, while the second person expands  the helmet laterally and removes it from above. Then inline  stabilization is re-established from above. And patient’s head  and neck are secured during airway management. Removal  of the helmet using a cast cutter while stabilizing the head  and neck can minimize cervical spine (C spine) motion in  patients with known C spine injury [9].    Box 48.3 Need for Ventilation or Oxygenation  1. Inadequate respiratory efforts  e Tachypnea  e Hypoxia  e Hypercapnia  e Cyanosis  2. Massive blood  resuscitation  3. Severe closed injury with need for brief hyperventi-  lation if acute neurologic deterioration occurs  4. Apnea  e Neuromuscular paralysis  e Unconscious    Next, the patient’s breathing, ventilation, and oxygenation  should be assessed, and any life-threatening derangements  must be treated. Physical examination, pulse oximetry, and  continuous end-tidal carbon dioxide monitoring should be  used. For proper ventilation the lungs, chest wall, and dia-  phragm must all function adequately.    The most common interventions performed during the  primary survey to support breathing are supplemental oxy-  gen delivery, assisted or mechanical ventilation, and tube  thoracotomy or chest tube insertion.    Sometimes it will happen that airway of the patient will  be patent but ventilation will be inadequate, so look for  the objective signs of inadequate ventilation. Ventilation  may be compromised by airway obstruction, altered  ventilatory mechanics, and central nervous system  depression.    1. Direct trauma to the chest, like rib fractures, lead-  ing to severe pain during breathing and leads to  shallow breathing and hypoxemia.   2. Elderly patients and other individual with pulmo-  nary dysfunction are at significant risk for ventila-  tor failure.   3. Intracranial injury can cause abnormal breathing  patterns and compromised adequacy of ventilation.   4. Cervical spinal cord injury can result in diaphrag-  matic breathing and interfere with the ability to  meet increased oxygen demands.   5. Complete cervical cord transection, which spares  the phrenic and results in abdominal breathing  paralysis of the intercostal muscles, and assisted  ventilation may be required.    1. Symmetrical rise and fall of the chest and adequate chest  wall excursion indicate the adequate ventilation, but  asymmetrical rise and fall suggests splitting of rib cage or  flail chest. Labored breathing may indicate an imminent  threat to the patient’s ventilation.   2. Listen for movement of air on both sides of the chest.  Decreased or absent sounds over one or both hemithora-  ces should alert examiner to the presence of thoracic   3. Use a pulse oximeter: This device provides information  regarding patient’s oxygen saturation and peripheral  perfusion.    Circulation must be assessed to determine the presence or  absence of shock after addressing the highest priorities in the  primary survey (airway and breathing). Shock is defined as  inadequate organ perfusion and tissue oxygenation. In the  trauma patient, shock is assumed to be hypovolemic/hemor-  rhagic, and resuscitation begins as soon as vascular access  can be obtained. The possibility of neurogenic shock (e.g.,  spinal cord injury) or cardiogenic shock (e.g., pericardial  tamponade) should also be considered. The focus of this seg-  ment of the primary survey should be assessing for the pres-  ence of shock, determining the cause (usually blood loss),  and beginning resuscitation.   Signs of poor perfusion include a weak pulse, cool or  clammy extremities, dry mucous membranes, pale skin,  and confusion. A normal mental status examination con-  firms the presence of acceptable cerebral perfusion. The  goal of resuscitation is to maintain tissue perfusion and  homeostasis.    External or internal bleeding source should be identified.  External hemorrhage is identified and controlled during the  primary survey. Rapid external blood loss is managed:    Internal hemorrhage areas are chest, abdomen, retroperi-  toneum, pelvis, and long bones. Chest X-ray, pelvic X-ray, or  focused assessment sonography in trauma (FAST) can be  done to identify the source of bleeding.    The primary focus is on rapidly determining a patient’s  mental status and neurologic function via physical exami-    nation. The Glasgow Coma Scale (GCS) is a rapid and  reliable way to quantify a patient’s level of consciousness  (Table 7.5). The GCS score allows for quick communica-  tion among clinicians about a patient’s current mental sta-  tus and can be important for decision-making. The  neurologic assessment also includes an examination of  the cranial nerves, pupils, and sensory and motor  function.    Exposure and environment are the final components of the  primary survey. While lowering priority, they are still vital to  the successful management of the trauma patient. The  patients should be completely exposed so that injuries can be  fully assessed. Decontamination may also be needed,  depending on the nature of the trauma. Protection from  hypothermia and continuous temperature monitoring are  essential.    Oxygenated inspired air is best provided via tight-fitting  oxygen reservoir face mask with a flow rate of at least 11 L/  min. Other methods (e.g., nasal catheter and non-breather  mask) can improve the inspired oxygen concentration.  Pulse oximetry is a noninvasive method of continuously  measuring the oxygen saturation (O, sat) of arterial blood.  It does not measure the partial pressure of oxygen (PaO),  and depending upon the position of oxy-hemoglobin dis-  sociation curve, the PaO, can vary widely. However a mea-  sured saturation of 95% or greater by pulse oximetry  strongly suggests adequate peripheral artery oxygenation  (PaO, > 70 mmHg).   Pulse oximetry requires intact peripheral perfusion and  can’t distinguish oxy-hemoglobin from carboxy-hemo-  globin or methemoglobin, which limits its usefulness in  patients with severe vasoconstriction and those with car-  bon monoxide poisoning. Profound anemia (Hb > 5 g/dL)  and hypothermia (<30 °C) decrease the reliability of the  technique. However, in most patient pulse oximetry is  useful as the continuous monitoring of oxygen saturation  provides an immediate assessment of therapeutic  intervention.    Warm resuscitation fluids should be given. IV fluid therapy  with crystalloids should be initiated. A bolus of 1—2 L of an  isotonic solution may be required to achieve an appropriate  response in adult patient.    Urine output monitoring is important to manage the fluid  therapy. Urine output reflects renal perfusion, and it is  accomplished by insertion of indwelling bladder catheter.  Contraindications to the placement of Foley catheter and  urethral injury should be suspected in the presence of:    1. Blood at the urethral meatus  2. Hemorrhage into the scrotum  3. High-riding prostate    Once the primary survey is completed, secondary survey is  started. If additional personnel is available, then part of  secondary survey can be conducted along with primary sur-    vey; however, it should be made sure that it does not inter-  fere with primary survey, as primary survey is the first  priority.   Secondary survey is a complete head to toe examina-  tion of the trauma patient which includes complete his-  tory taking and physical examination. During secondary  survey, a complete neurologic examination is conducted.    Patient’s GCS score is identified, radiographs are  obtained, and laboratory studies are conducted as  indicated.    A complete medical assessment includes history taking  and understanding the mechanism of the injury. Often,  patient is not in a condition to provide this history. In  such cases, it should be obtained from the family mem-  bers. The history taking involves identification of vari-  ous allergies, present medications, past history of any  illness, pregnancy, last meal taken, and the event of  trauma. The mechanism of injury must be understood  whether it’s inflicted by a penetrating or blunt trauma or  if the injury is thermal injury or due to hazardous  environment.    During physical examination in secondary survey, a sequence  has to be followed, which is examination of head, maxillofa-  cial structures, cervical spine and neck, chest, abdomen,  perineum/rectum/vagina, musculoskeletal system, and neu-  rologic system.    To examine the patient’s back and remove the spine board, at  least four persons are required for logrolling:    (a) Person one stands at the patient’s head to control the  head and C spine and two persons along the patient’s  sides to control the body and extremities.   (b) Three persons maintain the alignment of spine, as the  patient is rolled.   (d) Once the board is removed, patient is returned into the  supine position while maintaining the alignment of  spine.    Secondary survey starts with examination of head which  involves identification of injuries. The complete scalp  should be examined for lacerations, contusions, and evi-  dence of fractures. Other than these injuries, visual acuity,  pupillary size, hemorrhage of conjunctiva and/or fundi,  and ocular entrapment must be examined. These aspects  must be re-evaluated once the periocular edema subsides.   Visual acuity examination must be done by asking the  patient to read printed material such as handheld Snellen  chart. To exclude ocular entrapment, ocular movement must  be checked.    Intracranial lesions may be classified as diffuse or focal.  The focal lesions include epidural hematomas, subdural  hematomas, contusions, and intracerebral hematomas.    Hematoma or ecchymosis over the mastoid (Battle’s sign)  CSF otorrhea or rhinorrhea    Computed tomography (CT) scan of the head should be  carried out to accurately assess the neurologic injuries and  detect mass lesions. CT scan helps in diagnosing:    In a comatose patient, motor responses may be elicited by  pinching the trapezius muscle or with nail bed or supraor-  bital pressure. Testing for doll’s eye movements (oculoce-  phalic) the caloric test with ice water (oculovestibular) and  testing of corneal responses are deferred to a neurosurgeon.    Maxillofacial examination includes examination of soft tis-  sue, palpation of all the bony structures, checking of occlu-  sion, and intraoral examination. Trauma to the maxillofacial  region not associated with airway obstruction should be  treated once the patient is stabilized after the management of  life-threatening injuries.    Patients with maxillofacial trauma must be presumed to have  an unstable cervical spine injury unless it is proven other-  wise. The absence of any neurologic deficit does not exclude  the presence of any C spine injury. A complete cervical spine  radiographs and CT scan should be done to evaluate C spine  injury. The patient wearing any kind of helmet must be  removed with extreme care.    C spine injuries can result from one or a combination  of the following mechanism of injury:    A complete examination of neck includes inspection, pal-  pation, and auscultation. Inspection should be done to note  any blunt injury over the neck. Carotid arteries should be  palpated and auscultated for bruits. Penetrating injuries of  neck are potentially fatal. If the wound is deep, they should  not be explored in emergency department [13].   A cervical collar can be applied to the patients suspecting  the cervical spinal injury. Its role is to immobilize the C  spine. Cervical collars are divided into two groups: soft and  rigid collars. Soft collars are generally used for whiplash  injury; some surgeons prefer rigid collars. Rigid collars pro-  vide excellent immobilization in transverse and sagittal  planes compared with soft collars. However patient’s com-  fort is to be taken into consideration in selecting the collars.  The Philadelphia collar is available in two pieces having  front and back pieces; it is held together by Velcro straps to  support the neck [14].    Chest examination includes inspection, palpation, percus-  sion, and auscultation. Inspection of anterior and posterior  chest can identify conditions like open pneumothorax and  large flail segments. Contusions and hematoma over chest  suggest occult injury. Palpation of entire rib cage, clavicle,  and sternum helps in diagnosing fractures. Significant injury  may present with pain, dyspnea, and hypoxia.   Auscultation of high anterior chest helps in diagnosis of  pneumothorax, whereas posterior base auscultation reveals  hemothorax. Cardiac tamponade can be identified by the  presence of distant heart sounds and decreased pulse pres-  sure. Presence of distended neck veins suggests cardiac tam-  ponade and tension pneumothorax. A chest radiograph may  confirm the presence of hemothorax or _ simple  pneumothorax.    48.4.7.1 Classification of Chest Trauma  Immediate life-threatening chest injuries are to be identified  and treated during primary survey.   The basic principles of management remain the same with  the universal sequence of airway, breathing, and circulation  to be treated in that sequence.   It is necessary to recognize and address major injuries affect-  ing the airway during the primary survey. Airway patency  and air exchange should be assessed by listening for air  movement at the patient’s nose, mouth, and lung fields;  inspecting the oropharynx for foreign body obstruction; and  observing for intercostal and supraclavicular muscle retrac-  tions. Laryngeal injury can accompany major thoracic  trauma. Although the clinical presentation is occasionally  delayed, acute airway obstruction from laryngeal trauma is a  life-threatening injury. Injury to the upper chest can create a    palpable defect in the region of the sternoclavicular joint,  with posterior dislocation of the clavicular head, which  causes upper airway obstruction. Identification of this injury  is made by listening for upper airway obstruction (stridor) or  a marked change in the expected voice quality, if the patient  is able to talk. Management consists of a closed reduction of  the injury, which can be performed by extending the shoul-  ders or grasping the clavicle with a pointed instrument, such  as a towel clamp, and manually reducing the fracture. Once  reduced, this injury is usually stable if the patient remains in  the supine position.   The patient’s chest and neck should be completely exposed to  allow for assessment of breathing and the neck veins. This  may require temporarily releasing the front of the cervical col-  lar following blunt trauma. In this case, cervical spine immo-  bilization should always be actively maintained by holding the  patient’s head while the collar is loose. Respiratory movement  and quality of respirations are assessed by observing, palpat-  ing, and listening. Important, yet often subtle, signs of chest  injury or hypoxia include an increased respiratory rate and  change in the breathing pattern, which is often manifested by  progressively shallower respirations. Cyanosis is a late sign of  hypoxia in trauma patients. However, the absence of cyanosis  does not necessarily indicate adequate tissue oxygenation or  an adequate airway. The major thoracic injuries that affect  breathing and that must be recognized and addressed during  the primary survey include tension pneumothorax, open pneu-  mothorax (sucking chest wound), flail chest and pulmonary  contusion, and massive hemothorax.   Important: After intubation, one of the common reasons  for loss of breath sounds in the left thorax is a right mainstem  intubation. During the reassessment, be sure to check the posi-  tion of the endotracheal tube before assuming that the change  in physical examination is due to a pneumothorax or  hemothorax.   A tension pneumothorax develops when a “one-way valve”  air leak occurs from the lung or through the chest wall. Air is  forced into the pleural space without any means of escape,  eventually completely collapsing the affected lung. The  mediastinum is displaced to the opposite side, decreasing  venous return and compressing the opposite lung. Shock  results from the marked decrease in venous return causing a  reduction in cardiac output and is often classified as obstruc-  tive shock (Fig. 48.1). The most common cause of tension  pneumothorax is mechanical ventilation with positive-  pressure ventilation in patients with visceral pleural injury.  However, a tension pneumothorax can complicate a simple  pneumothorax following penetrating or blunt chest trauma in  which a parenchymal lung injury fails to seal or after a mis-    guided attempt at subclavian or internal jugular venous cath-  eter insertion. Occasionally, traumatic defects in the chest  wall also can cause a tension pneumothorax if incorrectly  covered with occlusive dressings or if the defect itself  constitutes a flap-valve mechanism. Tension pneumothorax  rarely occurs from markedly displaced thoracic spine frac-  tures. Tension pneumothorax is a clinical diagnosis reflect-  ing air under pressure in the affected pleural space. Treatment  should not be delayed to wait for radiologic confirmation.    Tension pneumothorax is characterized by some or all  of the following signs and symptoms:   Tracheal deviation away from the side of injury  Unilateral absence of breath sounds    Because of the similarity in their signs, tension pneumo-  thorax can be confused initially with cardiac tamponade.  Differentiation is made by a hyper-resonant note on percus-  sion, deviated trachea, and absent breath sounds over the    affected hemithorax, which are signs of tension pneumotho-  rax. Tension pneumothorax requires immediate  decompression and may be managed initially by rapidly  inserting a large-caliber needle into the second intercostal  space in the midclavicular line of the affected hemithorax.  However, due to variable thickness of the chest wall, kinking  of the catheter, and other technical or anatomic complica-  tions, this maneuver may not be successful [16].   When successful, this maneuver converts the injury to a  simple pneumothorax; however, the possibility of subsequent  pneumothorax as a result of the needle stick now exists, so  repeated reassessment of the patient is necessary. Chest wall  thickness influences the likelihood of success with needle  decompression. Recent evidence suggests that a 5 cm needle  will reach the pleural space >50% of the time, whereas an  8 cm needle will reach the pleural space >90% of the time.  Even with a needle of the appropriate size, the maneuver will  not always be successful. Definitive treatment requires the  insertion of a chest tube into the fifth intercostal space (usually  at the nipple level), just anterior to the midaxillary line.   In a tension pneumothorax, air from a ruptured lung  enters the pleural cavity without a means of escape. As air  pressure builds up, the affected lung is compressed, and all  of the mediastinal tissues are displaced to the opposite side  of the chest.   Large defects of the chest wall that remain open can result in  an open pneumothorax, which is also known as a sucking  chest wound. Equilibration between intrathoracic pressure  and atmospheric pressure is immediate. Air tends to follow  the path of least resistance; as such, if the opening in the  chest wall is approximately two-thirds of the diameter of the  trachea or greater, air passes preferentially through the chest  wall defect with each respiratory effort. Effective ventilation  is thereby impaired, leading to hypoxia and hypercarbia.  Initial management of an open pneumothorax is accom-  plished by promptly closing the defect with a sterile occlu-  sive dressing. The dressing should be large enough to overlap  the wound’s edges and then taped securely on three sides in  order to provide a flutter-type valve effect. As the patient  breathes in, the dressing occludes the wound, preventing air  from entering. During exhalation, the open end of the dress-  ing allows air to escape from the pleural space. A chest tube  remote from the wound should be placed as soon as possible.  Securely taping all edges of the dressing can cause air to  accumulate in the thoracic cavity, resulting in a tension pneu-  mothorax unless a chest tube is in place. Any occlusive  dressing (e.g., plastic wrap or petrolatum gauze) may be  used as a temporary measure so that rapid assessment can  continue. Subsequent definitive surgical closure of the defect  is frequently required [17].   A flail chest occurs when a segment of the chest wall does not  have bony continuity with the rest of the thoracic cage. This  condition usually results from trauma associated with multiple  rib fractures, that is, two or more adjacent ribs fractured in two  or more places (Fig. 48.2). The presence of a flail chest seg-  ment results in disruption of normal chest wall movement.  Although chest wall instability can lead to paradoxical motion  of the chest wall during inspiration and expiration, this defect  alone does not cause hypoxia. The major difficulty in flail  chest stems from the injury to the underlying lung (pulmonary  contusion). If the injury to the underlying lung is significant,  serious hypoxia can result. Restricted chest wall movement  associated with pain and underlying lung injury is major  causes of hypoxia. Flail chest may not be apparent initially if  a patient’s chest wall has been splinted, in which case he or she  will move air poorly and movement of the thorax will be  asymmetrical and uncoordinated. Palpation of abnormal respi-  ratory motion and crepitation of rib or cartilage fractures can  aid the diagnosis. A satisfactory chest X-ray may suggest mul-  tiple rib fractures but may not show costochondral separation.  Initial treatment of flail chest includes adequate ventilation,  administration of humidified oxygen, and fluid resuscitation.  In the absence of systemic hypotension, the administration of  crystalloid intravenous solutions should be carefully con-  trolled to prevent volume overload, which can further compro-  mise the patient’s respiratory status.   The definitive treatment is to ensure adequate oxygen-  ation, administer fluids judiciously, and provide analgesia to  improve ventilation. The latter can be achieved with intrave-  nous narcotics or local anesthetic administration, which    avoids the potential respiratory depression common with  systemic narcotics. The options for administration of local  anesthetics include intermittent intercostal nerve block(s)  and intrapleural, extrapleural, or epidural anesthesia. When  used properly, local anesthetic agents can provide excellent  analgesia and prevent the need for intubation. However, pre-  vention of hypoxia is of paramount importance for trauma  patients, and a short period of intubation and ventilation may  be necessary until diagnosis of the entire injury pattern is  complete. A careful assessment of the respiratory rate, arte-  rial oxygen tension, and work of breathing will indicate  appropriate timing for intubation and ventilation [18].   Massive hemothorax results from the rapid accumulation of  more than 1500 mL of blood or one-third or more of the  patient’s blood volume in the chest cavity (Fig. 48.3). It is  most commonly caused by a penetrating wound that disrupts  the systemic or hilar vessels. However, massive hemothorax  can also result from blunt trauma. In patients with massive  hemothorax, the neck veins may be flat as a result of severe  hypovolemia, or they may be distended if there is an associ-  ated tension pneumothorax. Rarely will the mechanical effects  of massive intrathoracic blood shift the mediastinum enough  to cause distended neck veins. A massive hemothorax is sug-  gested when shock is associated with the absence of breath  sounds or dullness to percussion on one side of the chest. This  blood loss is complicated by hypoxia. Massive hemothorax is  initially managed by the simultaneous restoration of blood  volume and decompression of the chest cavity.    Large-caliber intravenous lines and a rapid crystalloid infu-  sion are begun, and type-specific blood is administered as soon  as possible. Blood from the chest tube should be collected in a  device suitable for autotransfusion. A single chest tube (36 or  40 French) is inserted, usually at the nipple level, just anterior  to the midaxillary line, and rapid restoration of volume contin-  ues as decompression of the chest cavity is completed. When  massive hemothorax is suspected, prepare for autotransfusion.  If 1500 mL of fluid is immediately evacuated, early thoracot-  omy is almost always required. Patients who have an initial  output of less than 1500 mL of fluid, but continue to bleed, may  also require thoracotomy. This decision is not based solely on  the rate of continuing blood loss (200 mL/h for 2-4 h) but also  on the patient’s physiologic status. The persistent need for  blood transfusions is an indication for thoracotomy. During  patient resuscitation, the volume of blood initially drained from  the chest tube and the rate of continuing blood loss must be  factored into the amount of intravenous fluid required for  replacement. The color of the blood (indicating an arterial or  venous source) is a poor indicator of the necessity for thora-  cotomy. Penetrating anterior chest wounds medial to the nipple  line and posterior wounds medial to the scapula should alert the  practitioner to the possible need for thoracotomy because of  potential damage to the great vessels, hilar structures, and the  heart, with the associated potential for cardiac tamponade.  Thoracotomy is not indicated unless a surgeon, qualified by  training and experience, is present.   Cardiac tamponade (Fig. 48.4) most commonly results from  penetrating injuries. However, blunt injury also can cause the  pericardium to fill with blood from the heart, great vessels, or  pericardial vessel. The human pericardial sac is a fixed fibrous  structure; a relatively small amount of blood can restrict car-  diac activity and interfere with cardiac filling. Cardiac tam-  ponade may develop slowly, allowing for a less urgent  evaluation, or may occur rapidly, requiring rapid diagnosis and  treatment. The diagnosis of cardiac tamponade can be difficult  in the setting of a busy trauma or emergency room. Cardiac  tamponade is indicated by the presence of the classic diagnos-  tic Beck’s triad: venous pressure elevation (distended neck  veins), decline in arterial blood pressure, and muffled heart  sounds. However, muffled heart tones are difficult to assess in  the noisy examination area, and distended neck veins may be  absent due to hypovolemia. Additionally, tension pneumotho-  rax, particularly on the left side, can mimic cardiac tampon-  ade. Kussmaul’s sign (arise in venous pressure with inspiration  when breathing spontaneously) is a true paradoxical venous  pressure abnormality associated with tamponade. Pulseless  electrical activity (PEA) is suggestive of cardiac tamponade  but can have other causes, as listed above [19]. Insertion of a  central venous line with measurement of central venous pres-  sure (CVP) may aid diagnosis, but CVP can be elevated for a    variety of reasons. Additional diagnostic methods include  echocardiogram, focused assessment sonography in trauma  (FAST), or pericardial window. In hemodynamically abnor-  mal patients with blunt or penetrating trauma and suspected  cardiac tamponade, an examination of the pericardial sac for  the presence of fluid should be obtained as part of a focused  ultrasound examination performed by a properly trained pro-  vider in the emergency department (ED). FAST is a rapid and  accurate method of imaging the heart and pericardium. It is  90-95% accurate for the presence of pericardial fluid for the  experienced operator. Concomitant hemothorax may account  for both false-positive and false-negative ultrasound exams.  Prompt diagnosis and evacuation of pericardial blood are indi-  cated for patients who do not respond to the usual measures of  resuscitation for hemorrhagic shock and in whom cardiac tam-  ponade is suspected. The diagnosis can usually be made with  the FAST exam. If a qualified surgeon is present, surgery  should be performed to relieve the tamponade. This is best  performed in the operating room if the patient’s condition  allows. If surgical intervention is not possible, pericardiocen-  tesis can be diagnostic as well as therapeutic, but it is not a  definitive treatment for cardiac tamponade. However all  patients with acute tamponade and a positive pericardiocente-  sis will require surgery to examine the heart and repair the  injury. Pericardiocentesis may not be diagnostic or therapeutic  when the blood in the pericardial sac has clotted. Preparation  to transfer such a patient to an appropriate facility for defini-    tive care is always necessary. Pericardiotomy via thoracotomy  is indicated only when a qualified surgeon is available.    Abdominal injuries must be identified and managed aggres-  sively. It is not as important to arrive at a specific diagnosis  as it is to recognize the injury which requires a surgical inter-  vention. It is important to closely observe and re-evaluate the  abdomen to identify the blunt injury. The safest management  of penetrating wounds is a laparotomy.    Stab wounds commonly involve liver  (40%), small bowel (30%), diaphragm  (20%), and colon (15%)    Gunshot wounds commonly involve  small bowel (50%), colon (40%), liver  (30%), and abdominal vascular structures  (25%)    The diagnostic peritoneal lavage (DPL) was used to diag-  nose blunt and occasionally penetrating abdominal trauma,  but its use was decreased with the advancement of CT and  USG. Focused assessment sonography in trauma (FAST) is  very helpful to detect the presence of hemoperitoneum.    48.4.8.1 Focused Assessment Sonography  in Trauma (FAST) [22]  The ultrasound machine and water-based gel are necessary  to perform FAST.  Fast includes the following views:   2. Right upper quadrant view (RUQ): diaphragm-liver  interface and Morison’s pouch.   3. Left upper quadrant view (LUQ): diaphragm-spleen  interface and spleen-kidney interface    Contusions, hematomas, lacerations, and urethral bleedings  should be examined in the perineal area. The presence of blood  at urethral meatus suggests urethral injury. Inspect the scrotum  and perineum for ecchymosis or hematoma, also suggestive of  injury to the urethra. In patients with perineal hematoma or  high-riding prostate, Foley catheters should be avoided.   Rectal examination can be done to evaluate the presence  of blood within the bowel lumen. In patients with the risk of    vaginal injury, vaginal examination should be carried out.  Pelvic compressions should be carried out to identify any  pelvic fractures. Pelvic fractures can be suspected by the  presence of ecchymosis over iliac wings, pubis, scrotum, or  labia. The pelvic fracture can be divided into closed, open  book, and vertical shear fracture. Hemorrhage control and  fluid resuscitation will be in the initial management of major  pelvic disruption associated with hemorrhage. Pelvic binder  or sheet can apply sufficient stability for the unstable pelvis  at the level of greater trochanters of the femur bone.    The patient must be completely undressed for adequate  examination. Extremities should be inspected for deformi-  ties, abrasion, and contusions. Presence of tenderness on pal-  pation of bones and abnormal movement helps in  identification of occult fractures. Significant injuries of  extremities can exist without fracture being evident.  Ligament ruptures and a muscle tendon unit injury interferes  with active motions. The musculoskeletal examination is  incomplete without examination of the back of the patient.   Musculoskeletal injuries are a potential source of blood  loss in patients with hemodynamic abnormalities. The proper  splint application helps in blood loss control, reducing pain,  and preventing further soft tissue injury. Splinting is required  in the patients with joint dislocations.   Crush syndrome: it refers to the injured muscle which if left  untreated can lead to acute renal failure. Traumatic rhabdomy-  olysis ranges from asymptomatic illness with elevation of cre-  atine kinase level to a life-threatening condition associated with  acute renal failure and disseminated intravascular coagulation  (DIC). Early and aggressive fluid therapy protects the kidneys  and prevents renal failure in patients with rhabdomyolysis.   Compartment syndrome: develops when the pressure  within an osteofascial compartment of muscle causes isch-  emia and subsequent necrosis. Sometimes fasciotomy is  required to manage the condition.    Management of airway is challenging in patients with maxillo-  facial trauma. Securing airway in these patients is dependent on  the clinical status and the features of trauma. Before initiation of  airway management, a series of steps are to be planned. For  optimal care, one must have adequate knowledge of the specific    attributes of difficult airway. Also, the expertise in techniques  for managing the difficult airway, familiarity with devices, and  recognition of failed airway are necessary. A multidisciplinary  approach involving anesthesiologist, maxillofacial surgeon, and  a trauma expert must be a practice for better outcome (please  refer Chap. 7 for further reading).    1. Perry M. Advanced trauma life support (ATLS) and facial trauma:  can one size fit all? Part 1: dilemmas in the management of the  multiply injured patient with coexisting facial injuries. Int J Oral  Maxillofac Surg. 2008;37:209-14.   2. Perry M, Morris C. Advanced trauma life support (ATLS) and  facial trauma: can one size fit all? Part 2: ATLS, maxillofacial inju-  ries and airway management dilemmas. Int J Oral Maxillofac Surg.  2008;37:309-20.   3. Cowley RA. A total emergency medical system for the state of  Maryland. Md State Med J. 1975;45:37-45.   4. Johnson G. Trauma triage and trauma system performance. West J  Emerg Med. 2016;17:331-2.   5. Ray JM, Cestero RF. Initial management of the trauma patient.  Atlas Oral Maxillofac Surg Clin North Am. 2013;21(1):1-7.   6. Gondek S, Schroeder ME, Sarani B. Assessment and resuscitation  in trauma management. Surg Clin North Am. 2017;97:985-98.   7. Kovacs G, Sowers N. Airway management in trauma. Emerg Med  Clin North Am. 2018;36:61-84.   8. Barak M, Bahouth H, Leiser Y, Abu El-Naaj I. Airway management  of the patient with maxillofacial trauma: review of the literature and  suggested clinical approach. Biomed Res Int. 2015:724—32.   9. Roccia F, Cassarino E, Boccaletti R, Stura G. Cervical spine frac-  tures associated with maxillofacial trauma: an 11-year review. J  Craniofac Surg. 2007;18:1259-63.   10. Galvagno SM, Nahmias JT, Young DA. Advanced Trauma Life  Support® Update 2019: Management and applications for adults  and special populations. Anesthesiol Clin. 2019;37:13-32.   11. Sidwell R, Matar MM, Sakran JV. Trauma education and preven-  tion. Surg Clin North Am. 2017;97:1185-97.   12. Rodrigues IFDC. To log-roll or not to log-roll—That is the ques-  tion! A review of the use of the log-roll for patients with pelvic  fractures. Int J Orthop Trauma Nurs. 2017;27:36—40.   13. Rogers WA. Fractures and dislocations of the cervical spine: An  end-result study. J Bone Joint Surg Am. 1957;39-A:341-76.   14. Whitcroft KL, Massouh L, Amirfeyz R, Bannister GC. A com-  parison of neck movement in the soft cervical collar and rigid  cervical brace in healthy subjects. J Manipulative Physiol Ther.  2011;34:119-22.   15. Saillant NN, Sein V. Management of severe chest wall trauma. J  Emerg Crit Care Med. 2018;2:41.   16. Eckstein M, Suyehara D. Needle thoracostomy in the prehospital  setting. Prehosp Emerg Care. 1998;2:132—5.   17. Butler FK, et al. Management of open pneumothorax in tactical  combat casualty care: TCCC guidelines change 13-02. J Spec Oper  Med. 2013;13:81-6.   18. Pettiford BL, et al. The management of flail chest. Thorac Surg  Clin. 2007;17:25-33.    1998;113:1372-8. ries of the back: a prospective study of 230 patients. Ann Surg.  20. Matar ZS. The clinical profile of poly trauma and management of 1988;207:72-4.   abdominal trauma in a general hospital in the central region of the 22. Chaudhry R, Galagali A, Narayanan RV. Focused abdominal sonog-   Kingdom of Saudi Arabia. Internet J Surg. 2008;14:11. raphy in trauma (FAST). Med J Armed Forces India. 2007;63:62-3.    Open Access _ This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.  org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropri-  ate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.   The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in  a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.    49.1 Introduction  Soft tissue injuries are one of the most commonly encoun-  tered injuries in head and neck region and present especially  in the emergency department or surgical casualty. They can  be isolated soft tissue injuries, or injuries having concomi-  tant skeletal trauma. The frequent facial soft tissue injuries  include simple lacerations, abrasions, contusions, bites,  avulsions, and burns. These injuries are complicated by pres-  ence of vital anatomical structures like vessels, ducts, nerves,  and muscles. Presence of foreign debris and hematoma fur-  ther complicates the soft tissue injuries. The face is a region  of high esthetics and functional importance. Hence, there are  many factors that help to manage such injuries.    (i) Recognition of nature of the injury—Helps in logical  treatment planning that ultimately results in better  esthetic and functional outcomes.   (ii) Extent of injury—Many facial soft tissue injuries that  are relatively minor are treated in emergency depart-  ment by the oral and maxillofacial surgeons. These  wounds are managed by thorough cleaning, irrigation,  debridement, primary suturing, and cleaning whenever  needed. More complex wounds require special inter-  vention by taking the patient into operation theatre and  reconstructing using various grafts and flaps.   Timing of the injury—Any type of injury, by default,  should be attended at the earliest to maximize the prog-  nosis. The bottom line of many past and present litera-  ture is that the wounds of face and scalp should be   Department of Oral and Maxillofacial Surgery, Government Dental  College and Hospital, Medical College Premises, Nagpur,  Maharashtra, India    © The Association of Oral and Maxillofacial Surgeons of India 2021    primarily closed as soon as they are seen and as long as  active infection is not present.   To achieve this, the surgeon needs to understand the  etiopathogenesis, surgical anatomy, biomechanics of  tissue wound, biology of wound healing, and the art of  soft tissue repair.    The most common etiology of facial soft tissue injuries var-  ies according to the age, sex, and geographical distribution of  the population. Facial soft tissue trauma tends to occur in  certain areas of the head depending on the causative mecha-  nism. It typically includes the T-shaped area that includes  forehead, nose, lips, and chin, followed by the occiput and  anterior temporal areas.    (a) Falls are by far the most common cause, accounting for  48-51% of the injuries [1, 2]. This etiology has a trimodal  distribution. The first peak is 2-3 years, when toddlers  begin to walk and fall into objects. There is smaller peak  during the second and third decades and then a steady rise  after age of 50 years. Alcohol consumption is a major fac-  tor for soft tissue injuries due to fall between 30 and 50  years. Medical comorbidities such as epilepsy are also the  causative factor for falls in old age group.   (b) Non-fall impacts. Approximately 16% of facial soft tissue  trauma is the result of a non-fall impact with structural ele-  ment such a door, wall, or window frame. Other collisions  with furnishings such as tables also counted. These types of  injuries peak in children younger than 5 years. The common  areas include the forehead, nose, and anterior temples.   (c) Assaults account for 16-32% of facial soft tissue inju-  ries [1]. The assaults are most commonly caused by fists,  kicks, and blunt instruments. The injuries due to assault  occurs more frequently among young men on left side of  face. Alcohol consumption is a factor in two-thirds of  these patients.    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1-15-1346-6_49    Road traffic accidents cause 6—-13% of facial trauma [2]  where soft tissue injuries may occur alone or in combination  with other fractures. The peak incidence is seen in young  men at 15-24 years of age [3]. Impact from steering wheel,  dashboard, and windshields results in most lacerations.  Sporting injuries account for about 8% of facial soft  tissue trauma [1], commonly occurring in young men.  The forehead, nose, and teeth are the most likely areas to  be injured. Concomitant facial fractures like nasal frac-  tures, avulsive teeth injuries, and mandibular fractures  are also common among these group of patients.  Others include occupational injuries, bites from  humans or animals, and other miscellaneous causes.  Occupational injuries [3] account for 5% of facial trauma  and are primarily seen in young men. The risk of dog  bites is higher for children aged 5—9 years and decreases  with age. The frequency of facial injuries is highest in  children younger than 4 years, in whom nearly 65% of  dog bite injuries involve the face. In adults, it is about  9%. Most dog bite injuries are from dogs known to per-  son or occur near home. These injuries typically involve  the cheek, lips, forehead, and nose.    (1) Mechanical or physical injuries:  e When injury is caused due to blunt force:    1. Abrasions  2. Contusions  3. Lacerations  e When injury is caused due to sharp force:  1. Incised wounds  2. Chop wounds  3. Stab/punctured wounds  (1) Thermal injuries:  e Due to excessive cold: e.g., frostbite  e Due to moist heat: e.g. burns and scald wounds  (I) Chemical injuries: Due to corrosive acids and  alkalis  (IV) Miscellaneous: Electricity, lightning, etc.  (V) Explosions: Blast injuries    1. Simple—soft tissue injuries without much tissue  loss and can be managed conservatively. Heals rap-  idly without any permanent deformity.   2. Grievous injuries—described under Section 320  of Indian Penal Code as any injuries that endanger  life and cause severe disfigurement or deformities  like permanent hearing loss, vision loss, and  severe head injuries. Tooth fracture or tooth loss  following a blow in an interpersonal violence is  also considered a grievous injury and penalized by  the court of law. These injuries heal slowly and  incompletely.   3. Dangerous—the grievous injuries that endanger life  immediately after impact (Box 49.1).    Ill. Chemical Injuries 7 :  a. Corrosive acids  b. Corrosive alkalis    a. Electrical Injuries  b. Lightening trauma  c. X-radiation injuries  d. Radioactive injuries    Fig. 49.1 (a) Showing open wound where fractured left clavicle is visible from the wound surface. (b) Open wound of maxillofacial region where    (C) Based on the communication of the injury with the  external environment   Closed wound: Only the underlying tissue and/or  structures are damaged without breaking the skin.  Examples of closed wounds include hematomas,  contusions, and crush injuries. These types of  wounds are not contaminated and, hence, heal on  their own without any sequelae.  Open wounds: There is a break in the skin, which  exposes the underlying structures to the external  environment. Open wounds include simple and com-  plex lacerations, avulsions, punctures, abrasions,  accidental tattooing, and retained foreign body with  a tendency to heal with scarring. These injuries  require extensive exploration and debridement  followed by a course of antibiotic regimen for  uneventful healing (Fig. 49.1).    (D) According to the facial subunit(s) involved. The  major esthetic subunits on the face are the scalp, fore-  head, nose, periorbital region, cheek, perioral region,  auricle, and neck [4].   These major facial esthetic subunits are further divided  into smaller subunits by location. The individual sub-  units must be reconstructed individually one by one in  order to attain good esthetics (Fig. 49.2).    The nerve injuries are further classified into neuro-  praxia, axonotmesis, and neurotmesis (Seddon’s  classification of nerve injuries [5]). Sunderland [6]  further revised this classification of nerve injuries  based on the histologic degree of nerve damage.  There should be careful evaluation of sensory and  motor components of the nerves in the involved  region for proper treatment. The most commonly  encountered nerve injuries in maxillofacial region  are the facial nerve and trigeminal nerve.   Injuries to arteries and veins—The face is a  highly vascular region where even a small injury  leads to significant bleeding. Any wound in maxil-  lofacial region should be attended in emergency  setting at the earliest due to chances of injury to the  extensive vascular network which necessitates  hemostasis.   Injuries to parotid duct—Seen in cases of deep  lacerations on cheek at the region of parotid duct.  If undiagnosed and untreated, this injury can lead  to cumbersome sequelae of parotid fistula. Parotid  duct injury is suspected if the laceration involves  an imaginary line joining the tragus of the ear to  the upper lip. In such cases, exploration is per-  formed to evaluate the injury, and suturing should  be done using a stent to establish patency of the  duct.    no devitalized tissue are called tidy. These wounds  are closed primarily. Examples are surgical inci-  sions, cuts from glass, and knife wounds.   Untidy wounds—Untidy wounds result from  crushing, tearing, avulsion, vascular injury, or burns  and contain devitalized tissue. Such wounds must  be managed by wound excision. The devitalized tis-  sue is excised, and the untidy wound is converted  into the tidy wound before proper closure is  achieved. The chances of infection are high if inad-  equately managed.    (G) CDC classification of surgical wounds  A surgical wound is a wound created by incisions and  placement of drains during surgeries.  Surgical wounds can be classified into four different    Class I: Clean wounds. They show no signs of  infection or inflammation. They often involve the  eye, skin, or vascular system. It is often due to non-  penetrating (blunt) trauma.   Class II: Clean-contaminated wounds. Although  the wound may not show signs of infection, it is at an  increased risk of becoming infected because of its    location. For example, surgical wounds in the respi-  ratory tract like oropharynx and gastrointestinal tract  may be at a high risk of becoming infected.  Class III: Contaminated wound. A surgical wound  in which an outside object has come into contact  with the skin and has a high risk of infection. For  example, a gunshot wound may contaminate the skin  around where the surgical repair occurs.  Class IV: Dirty-contaminated or infected wounds.  The wounds that have been exposed to fecal material  and have a high bacterial load.  This wound classification guides in choosing appropriate  treatment as well as helps in predicting post-repair form and  function.    The common clinical presentation of soft tissue injuries  included abrasions, contusions, and lacerations.    1. Abrasions—(also known as gravel rash) (Fig. 49.3)—It  is destruction of the superficial layer of skin only. It is  caused by frictional forces that are light enough to erode  only the superficial layer of epidermis. It can be scratches    Fig. 49.3 Showing multiple abrasions over face involving the supraor-  bital region, nose, upper lip, and chin    or linear type of abrasion, graze or sliding abrasion, pres-  sure abrasions, and impact abrasions.   The healing of abrasions takes place from the periphery  of the wound towards the center by new growth of epithe-  lial cells. The wound is bright red in color for the first  12-24 h due to extravasation of blood which dries up to  form a red scab. After 2-3 days, a reddish-brown scab is  formed. After 4—7 days, epithelium grows and covers the  defect under the scab, which gives it a dark brown to  brownish-black appearance. After 7 days, the scab dries  and ultimately falls off, leaving depigmented bright pink-  ish area underneath, which attains its normal pigmenta-  tion gradually over a period.   . Contusions (bruising) (Figs. 49.4 and 49.5)—This is  effusion of blood into the tissues, due to the rupture of  small blood vessels at the site of impact. There is no  destruction of the superficial layer of skin. The subtypes  are (a) intradermal, (b) subcutaneous, and (c) deep.   A bruise heals by disintegration of extravasated blood.  The red cells in the wound are hemolyzed, and the hemo-  globin molecule is broken down into hemosiderin, hema-  toidin, and bilirubin by the action of enzymes.   This type of injury demonstrates a change in the color of  the wound according to the time lapsed after injury: red at  the time of injury, blue within few hours to 3 days, and    Fig. 49.4 Showing contusion wound over right cheek and periorbital  ecchymosis of the right eye. The color changes can be appreciated  intraorally    bluish-black to brown color due to deposition of hemo-  siderin from the extravasated RBCs, by the 4th day. In  5-6 days, the wound appears greenish due to disintegra-  tion of hemoglobin to hemosiderin. Between 7 and 12  days, the wound appears yellow due to the presence of  bilirubin which is the final disintegrated product from  hemoglobin. The wound appears normal by 2 weeks. The  various factors affecting the color of contusion include  the depth of the bleeding, amount of extravasated blood,  and overlying skin color.   3. Lacerations—It is the tear or split of skin, mucous mem-  brane, muscle, or internal organs produced by the appli-  cation of blunt force to a broad surface area, which    Fig. 49.6 Showing split lacerated wound over the nose, columella,  lower lip, and chin    crushed or stretched tissues beyond the limits of their  elasticity. They can be split lacerations (Fig. 49.6), stretch  lacerations, shearing lacerations, and cut lacerations  (Fig. 49.7).   4. Incised wounds—The wound is longer than it is deep. It  is caused by the pressure and friction of any sharp object  against the soft tissues (Fig. 49.8).   5. Chop wounds (slash wounds)—They are deep bigger  wounds with gaping caused by a blow with the sharp-  cutting edge of a heavy weapon, like an axe or chopper.   6. Stab or punctured wounds—Produced when the force  is delivered along the long axis of a narrow or pointed    Fig. 49.8 Showing incised wound extending from dorsum of the nose  till pre-auricular region; caused by knife in a case of assault   spear, arrow, screw driver, etc. into the depths of the body.   This type of wound is deeper than its length and width.   (a) Penetrating wounds—When an object pierces the  skin and enters a cavity of body or a viscus creating  a localized path of entry leaving it an open wound  (Fig. 49.9). In head and neck region, this type of  injuries should be assessed for upper airway and  bleeding as direct trauma to vital structures occurs  along with facial bone fractures. Careful explora-  tion of the wounds should be performed, and any  impacted debris should be removed before  closure.   (b) Perforating wounds or through-and-through  puncture wounds—Produced when the object enters  the body at one surface and exits at another surface  without causing much tissue loss. The wound of  entry is larger with inverted edges, and the wound of  exit is smaller with everted edges. They are consid-  ered to be sterile wounds (Fig. 49.10).    body part is crushed between two heavy blunt objects.  Most severe trauma cases will have this type of injury.  Crush injuries have ragged edges, varying amounts of  devitalized tissue, and, sometimes, tissue loss.    Avulsion can be considered a very severe form of abra-  sion, wherein all layers of skin are torn off and the under-  lying structures are grossly exposed. The term avulsion  can also mean complete loss of a small body part such as  eyelid, fingertip, part of ear, etc.    49 Management of Soft Tissue Injuries in the Maxillofacial Region 1003    Fig. 49.9 Showing penetrating wound. (a) Only the entry site is seen over the right temporal region. (b) The object remains dislodged within the  body cavities    Fig. 49.10 Showing gunshot wound injuries. (a) Picture showing entry wound over pre-auricular region. (b) Showing exit wound over right  infraorbital region on opposite side   heat, friction, electricity, radiation, or chemicals. Most  burns are from hot objects (including fluids) and fire.  Burns cause severe skin damage where the cells die.  Burns are highly painful injuries which require specific  treatment as distinct from other injuries depending on the  degree of burn.  The clinical presentation of burns depends largely on the  depth of injury. Superficial burns (first degree) are con-  fined to the epidermis. They are characterized by severe  pain, dryness, and redness of skin. Superficial partial-  thickness (second degree) burns extend into the papillary  dermis. The skin is moist and red and blanches with pres-  sure. Blisters are common in this type of injury. Deep  partial-thickness burns extend into the reticular dermis.  The skin is dry and appears yellow or white with minimal  blistering. Full-thickness burns extending to the entire  depth of dermis are classified as 3rd degree. These are  very severe injuries. The skin is stiff, leathery, and brown,  but pain is not a common feature. Fourth-degree burns  involve charring of skin and affect the deeper structures  like fat and muscle. The skin is dry, black, and painless.   All trauma patients should be assessed and managed initially  according to the principles of Advanced Trauma Life  Support. Soft tissue injuries of the head and neck region can  be accompanied by significant swelling and bleeding leading  to airway compromise. The patient also should be assessed  for associated ophthalmologic, intracranial, and cervical  spine injuries.    Once the patient has been evaluated for life-threatening inju-  ries and stabilized as necessary, a thorough and focused his-  tory and physical examination of the head and neck should  be performed. History includes timing and mechanism of  injury.   Early treatment of soft tissue injuries is associated with  optimal esthetic outcomes. Determining the mechanism of  injury may help the surgeon in managing the wounds with  special consideration. For example, crush injuries may result  in a larger area of compromised tissue than appreciated on  initial examination. Tissue that appears healthy initially may  subsequently necrose and may require serial debridement.   The site(s), depth, and nature of all wounds should be  noted. Presence of nonviable tissue, gross contamination,  and any foreign body like dirt and debris are important to  discern.    Palpation helps to identify the presence of underlying  bony injuries. Palpation can be done through the open wound  itself.    The principles of management of soft tissue injuries include  the control of bleeding, copious irrigation of the wound,  debridement of devitalized tissue, and removal of foreign  bodies before closure.    (a) Control of bleeding—Blood loss is minimized by  applying local pressure using hands and pressure dress-  ings. The wound should be examined thoroughly with  suction, irrigation, and meticulous dissection to identify  the offending vessel, if any. If local pressure fails to  achieve hemostasis, local hemostatic agents can be used.  Local anesthesia with adrenaline helps in control of pain  as well as bleeding through its vasoconstrictive action. If  generalized oozing is still present which is hampering  the ability of a surgeon to close the wound, systemic  measures like injectable vitamin K, tranexamic acid, or  ethamsylate can be given, provided the blood investiga-  tions (INR, BT, CT) are within normal limits.   nated wounds should be copiously irrigated with sterile  saline. The fluids may be warmed to 37 °C to promote  cellular activity. The cleanser should be nontoxic and  have a neutral pH. Alkaline soaps are best avoided.   (e) Wound excision (also known as wound debridement  or toileting of the wound)—Serial debridement of con-  taminated and untidy wounds done to remove all the  necrotic tissues like devitalized muscles, tendons, and  fascia and comminuted bony fragments that have lost the  soft tissue cover of periosteum and are hanging within  the wound, in order to aid in uneventful and optimum  healing. The blunt contused margins of skin are also    excised using sharp scissors, and the wound margins are  freshened up. The toilet of any wound should be done in  a systematic layer-wise manner from superficial to deep  (Fig. 49.11).   Closure—lIdeally, facial soft tissue injuries should be  closed as early as possible. Primary closure of a wound  should be completed within 8 h of injury when possible  [9]. Early intervention and closure decreases the risk of  infection as well as optimizes the functional and cos-  metic result. Basic principles of suturing should be met,  which include precise approximation and eversion of the  skin edges, avoidance of excessive tension, and layer-  wise closure to prevent dead space and_ fluid  accumulation.   If gaping of the lacerated margins or tissue loss is pres-  ent that cannot be closed primarily, the tissue can be  managed by regular dressing and allowed to heal sec-  ondarily. Revision surgeries to improve esthetics and  function are performed after minimum of 9 months.  Reconstruction [10]—Done in cases of extensive  degloving injuries. There are several options for soft tis-  sue reconstruction using flaps. Starting from local,  regional, distant flaps and free microvascular flaps,  depending on the type, location, and extent of the injury  (Box 49.2).    a. Axial — flap with one  blood vessel. Further  classified as  fasciocutaneous,  musculocutaneous,  venous and direct. E.g. —  Radial forearm flap,  nasolabial flap, submental  flap etc.   d. Free Flaps — Flaps having their  own blood supply, connected to  the defect using microvascular  technique.    laterally into the defect but not  adjacent. Undermined to reach the  area.    Wound dressings are sterile pads used to cover the wounds.  Lister [11] introduced antiseptic dressings by soaking  gauze in carbolic acid. The dressings should be clean and  provide a warm and moist environment for the successful  wound healing. The dressings should be frequently    changed in order to keep the wound free from bacterial  load. Antibacterial ointments must be applied over the  wound to keep it lubricated and free from bacteria. The  dressings are selected on the basis of two concepts: occlu-  sion and absorption. The reasons for placing a wound    (i) Protection the wound from elements of nature  (11) Prevention of bacterial contamination  (iii) Application of compression where required  (iv) Absorption of exudate  (v) Facilitation of hemostasis  (vi) Prevention of further inadvertent trauma to wound  site  In selected cases, the dressing is modified to achieve  additional purposes such as  (vii) Relief of pain  (viii) Application of topical antibiotic  (ix) Removal of slough and foreign bodies from the  wound    Studies [12] have demonstrated that the rate of epithelializa-  tion under a moist occlusive dressing is twice that of a wound  that is left uncovered and allowed to dry. An occlusive dress-  ing provides a mildly acidic pH and low oxygen tension on    the wound surface, which is conducive for fibroblast prolif-  eration and formation of granulation tissue.   However, wounds that produce significant amounts of  exudate or have high bacterial counts require a dressing  that is absorptive and prevents maceration of the surround-  ing skin. These dressings also need to reduce the bacterial  load while absorbing the exudate produced. Placement of a  pure occlusive dressing without bactericidal properties  would allow bacterial overgrowth and worsen the  infection.   The various types of dressings [13] can be enumerated as  in Table 49.1.    1. Hyperbaric oxygen therapy—uses oxygen as a drug  and the hyperbaric chamber as a delivery system to  increase PO2 at the target area. It involves inhalation of  100% oxygen at 1.9-2.5 atm, for sessions of 90-120 min  each. Treatments are given once daily, five to six times  per week and should be given as an adjunct to surgical or  medical therapies. Clinical evidence of wound improve-  ment should be noted after 15—20 treatments.   Provide a moist and cool environment  Composed of methylcellulose, pectin, and  Absorb fluids and convert them into a gel that    Kind of  dressing Examples Properties  Protective Gauze Inexpensive, readily available  primarily  Polymeric films (Opsite, Transparent, waterproof dressing  Tegaderm)  Absorbent Hydrogels Mostly contain water  Hydrocolloids  gelatin  covers the wound  endings  Bioactive Antimicrobial dressings    that is impregnated with  O-tolylazo-O-tolylazo-B-naphthol  Xeroform—hydrophobic dressing containing  3% bismuth tribromophenate in a petrolatum  base, which helps mask wound odors and has  antimicrobial activity against Staphylococcus  aureus and Escherichia coli    Flat, shallow wounds such as skin graft  donor sites, superficial burns, and  abrasions    Mechanism of action—HBO therapy can increase tissue  PO2 ten times higher than usual. The higher PaO2 is suf-  ficient to supply the tissue with all its metabolic require-  ments even in the absence of hemoglobin. This elevated  level lasts for 2-4 h after termination of HBO therapy and  induces synthesis of endothelial cell NO synthase as well  as angiogenesis. Oxygen stimulates angiogenesis,  enhances fibroblast and leukocyte function, and  normalizes cutaneous microvascular reflexes, thus aiding  in healing of chronic, complicated, non-healing wounds.   2. Negative pressure-assisted wound therapy—Argenta  [14] and associates originally described the use of nega-  tive pressure to assist in wound closure in 1997. By  applying subatmospheric pressure to wounds, they dem-  onstrated removal of chronic edema, an increase in local  blood flow, and stimulation of granulation tissue. This  technique may be used on acute, subacute, and chronic  wounds. The wound is filled with a foam substance. A  drainage tube is inserted into, or laid on, the foam, and the  part is then covered with impermeable film. Suction is  applied at around 125 mmHg between changes of  dressing.    It is a rapidly spreading necrotizing soft tissue infection, also  known as flesh-eating disease. It is one of the most challeng-  ing infections faced by the maxillofacial surgeons due to its  diagnosis and management. The most common bacteria  responsible for the fascial necrosis are hemolytic  Streptococcus and Staphylococcus.   It is foul-smelling with loss of skin and superficial subcu-  taneous tissue, having patchy blackish necrosis and frank  pus along with the raw surface of the wound, margins of  which are pale and spreading in nature. If it involves the skin  of scrotum, it is known as Fournier’s gangrene.   The prompt diagnosis and aggressive treatment is the key  to manage this complicated condition. Removal of the  offending factors like carious tooth and infected foreign  material is the prime step followed by aggressive debride-  ment and desloughing involving the normal tissue margins  under the antibiotic coverage and adequate anesthesia. Once  the wound is free of the active infection, showing healing  margins with no evidence of pus, it is reconstructed with the  skin grafts (Fig. 49.12).    Fig. 49.12 Depicting a case of necrotizing fasciitis of the right side of the neck due to infection from right mandibular third molar. The patient  was promptly and aggressively managed by sequential debridement followed by anterolateral thigh skin graft    ¢ Cellular infiltration—Polymorphonuclear leukocytes initially, followed by  monocytes within 24 h, which become dominant by the 5th day and actively  engaged in phagocytosis   ¢ Formation of new blood vessels at the edges of wound (neovascularization)    e With time, the number of fibroblasts increases that are active in synthesis of  extracellular collagen and proteoglycans (collagen synthesis)   ¢ The fibroblasts in the wound are closely followed by the endothelial buds of  capillaries. The wound is filled with vascular granulation tissue containing new  capillaries, fibroblasts, macrophages, and mast cells   ¢ An intrinsic increase in the mechanical strength of the wound at the end of this    e Extensive remodeling as a result of a decrease in the numbers of fibroblasts    and macrophages concurrent with a decrease in vascularity  ¢ Increase in wound strength  ¢ Formation of scar tissue    The three phases of repair in soft tissue wounds are overlap-  ping and include    ¢ The inflammatory phase  e The proliferative phase  e The maturation phase (Table 49.2)    Any alteration in the local environment of the wounds or  the systemic status of the patients can influence the normal  process of wound healing.   49.11 Types of Wound Healing  The various types of wound healing include:  Primary intention    Primary intention—occurs when full-thickness wound  edges are approximated shortly after the primary wound  has been created. This type of closure is generally avoided  in grossly contaminated wounds, in wounds that cannot  be completely debrided, and in wounds where further tis-  sue loss is anticipated as in blast injuries.   2. Delayed primary closure—Primary closure is delayed to  allow host inflammatory and immune responses to control  contamination. It is typically completed 3-4 days after the  initial injury but depends on the particular characteristics  of the wound. Serial debridements may be performed until  the full extent of tissue devitalization is determined.    3. Secondary intention—healing is by natural biologic  processes without surgical intervention, and it usually  occurs in large wounds associated with soft tissue loss or  avulsion. It involves epithelialization and collagen depo-  sition for wound healing. Contraction is the most impor-  tant phenomenon in the spontaneous closure of large  open wounds.    Complications in the normal process of wound healing may  occur due to presence of various local and systemic factors  which exert a negative impact (Table 49.3).   One of the frequently observed complications is “abnor-  mal wound healing” which presents in different forms such  as keloids and hypertrophic scars. These are proliferative  scars characterized by excessive net collagen deposition.  Keloids and hypertrophic scars (Fig. 49.13) differ histologi-  cally from normal scars. The clinical appearance of the two  types of scar is described in Table 49.4.   Keloids and hypertrophic scars contain collagen bun-  dles aligned in the same plane as the epidermis. Tension    Fig. 49.13 Showing. (a) keloid type of scar and (b) hypertrophic scar healing   The collagen bundles are thicker and form a nodelike structure in  the deep layer of skin   Cannot be prevented and are often refractory to medical and  surgical intervention   Occur above the clavicles, on the trunk, on the upper extremities,  and on the face   Grow beyond the borders of the original wounds and rarely regress  with time   Intralesional 5-fluorouracil, bleomycin, and verapamil used  according to the established treatment protocols.   Refractory cases after 12 months of therapy should be considered  for surgical excision in combination with adjuvant therapy.  Excision alone results in a high recurrence rate of 50-100% and  enlargement of the keloid.   Immediate postoperative electron beam irradiation or brachytherapy  with iridium-192 reduces recurrence rates.    over the edges of the wound signals the formation of acti-  vated fibroblasts resulting in excessive collagen  deposition.   Scars perpendicular to the underlying muscle fibers  tend to be flatter and narrower, with less collagen forma-  tion than when they are parallel to the underlying muscle  fibers. As muscle fibers contract, the wound edges  become reapproximated when they are perpendicular to  the underlying muscle and tend to gape if placed parallel  to it, leading to greater wound tension and _ scar  formation.   Contain islands of aggregates of fibroblasts, small vessels, and collagen  fibers throughout the dermis    Prolonged inflammation and insufficient resurfacing (e.g., burn wounds)  promote hypertrophic scarring   Raised scars within the confines of the original wound and frequently  regress spontaneously   Represent a reversible hyperproliferative scar phenotype that regresses  when the original stimulus (skin tension, stimulatory growth factors) are  removed   Pressure and silicone therapy combined with selective localized  corticosteroid injections in resistant areas.   Bleomycin, 5-fluorouracil, and verapamil can be used as adjuncts to  corticosteroid therapy.   Laser therapy to reduce scar thickness, resurface scar texture, and treat  residual redness, telangiectasias, or hyperpigmentation.   Early surgery is indicated if the scar causes functional impairment. Scar  contracture release procedures in the neck and axilla are best performed  with flaps to improve functional and cosmetic outcomes.   Widespread large hypertrophic scars may require serial excision or tissue  expansion.    The four strategies that reduce adverse scarring immediately  after wound closure are:    ¢ Layer-wise closure as to avoid gaping within the layers of  the wound    Postsurgical taping of the wound for 3 months can  reduce scarring. Moisturizing lotions and moisture-reten-  tive dressings (silicone sheets and gels) can reduce the  thickness, discomfort, and itching and improve the appear-  ance of the scar.    1. Use of growth factors—intimate role in the regulation  of all phases of wound healing, i.e., chemotaxis, prolif-  eration, matrix synthesis, inflammation, and angiogen-  esis. The enhancement of soft tissue wound healing can  be done by various methods. Topical application of  growth factors in a vehicle or by direct seeding of cells  topically on the wound can enhance healing. Placement  of growth factors or cells can also be done with a fibrin  sealant or glue. Use of platelet-rich plasma (PRP) by  degranulation of platelets with the secretion of its con-  tents of growth factors into the surrounding fibrin matrix  or, more recently, use of tissue-engineered equivalents  of skin or mucosa can provide a scaffold that enhances  healing.   2. Gene and stem cell therapy—in which the gene  encoding for the therapeutic growth factor or protein is  directly transfected into host cells. This is a promising  approach for the treatment of acute and chronic  wounds.   3. Tissue engineering—In 1987, the National Science  Foundation bioengineering panel defined tissue engineer-  ing as “the application of the principles and methods of  engineering and the life sciences toward the development  of biologic substitutes to restore, maintain, or improve  function.”    (a) Epidermal substitutes—These are autografts taken  from split-thickness skin grafting or from cell line  bioreactor expansion and grown in laboratory until  enough tissue is produced to be transferred to the  wound later.   (b) Dermal substitutes—When the wound is deep and  the dermis is destroyed, epidermal substitutes are not  enough to ensure wound healing. The dermis is  replaced by the one manufactured in the laboratory  from the patient-specific cells. This dermis is essen-  tial to maintain mechanical resistance and occlude  the surface of the wound.    (c) Bilayer substitutes—Integra, developed in 1981, was  the first acellular bilayer and has been used success-  fully to treat burns and chronic wound patients.    Proper assessment and classification of soft tissue injuries is  the primary step in management. Early intervention and clo-  sure of soft tissue injuries is associated with optimal func-  tional and esthetic outcomes as well as decreases the risk of  complications. The basic principles of management of soft  tissue injuries include the control of bleeding, copious irriga-  tion of the wound, debridement of devitalized tissue, and  removal of foreign bodies before closure. Administration of  antibiotics and tetanus prophylaxis play a vital role in man-  agement of contaminated wounds. Wound dressings are  mandatory to protect wounds postoperatively and facilitate  ideal healing. Soft tissue injuries resulting in loss of tissue  must be reconstructed using flaps which may be local,  regional, distant, or free microvascular flaps, depending on  the type, location, and extent of the injury. Innovative options  such as growth factors, stem cell therapy, and bioengineered  skin substitutes may be considered.    A 23-year-old male patient met with a road traffic accident  and suffered from a perforating injury over the nose, extend-  ing to right infra-orbital region. After initial resuscitating of  the patient and ruling out the head injury component, the  patient was taken up for the management of soft tissue and  hard tissue injuries under general anesthesia. Through the  existing lacerated wound, open reduction and internal fixa-  tion was done within 48 h of the trauma. Simultaneously, the  soft tissue closure was performed layer-wise. Closure of the  muscle layer was performed followed by the subcutaneous  tissue and finally the skin (Fig. 49.14a-e).    A case scenario of a 67-year-old male patient who reported  to the department of Oral and Maxillofacial Surgery. He was  a victim of ballistic injury while he was working in a market-  place. The penetrating pathway of the bullet could be traced    Fig. 49.14 Case scenario 1(a—e): Soft tissue management of a road traffic accident victim    having an entry site over left cheek. An extensive and careful  exploration was performed in the OT under general anesthe-  sia after the sections of 3D CT face were obtained  (Fig. 49.15a—g). The comminuted fracture of the mandible  was reconstructed using reconstruction plate. The bullet was  found to be lodged in the carotid triangle just above the  bifurcation of the common carotid artery.   Soft tissue management in such type of ballistic injuries  becomes very critical. Since the bullet is a foreign material,  it has to be removed from the soft tissues. The approach  could either be through the entry wound but due to deep seat-    ing of the bullet into the neck and proximity of vital struc-  tures, one should always think of an extensive approach. The  neck dissection was carried out in this case to remove the  bullet from the bifurcation of common carotid artery in as  atraumatic manner as possible. Bidigital palpation is a cru-  cial step to locate the foreign body in this region. One inter-  esting fact about such injuries is that though they are  extensive with crushed and comminuted fractures and they  are sterile due to the heat generated by the velocity of the  bullet along its path. Such injuries are less prone to  infection.    Fig. 49.15 (a—g) Case Scenario 2: Soft tissue management in a ballistic injury    ; : : agement update. Int J Oral Maxillofac Surg. 2005;34(5):464—72.  careful debridement remains the mainstay of treatment of all @ Janis 1: Essentials oF plastic sucsety. 2nd edn, Bosca Raton, FL:    types of soft tissue injuries. Quality Medical; 2014. p. 316-21, 382-5, 390, 480.   10. Frodel JL, Holt GR, Larrabee WF Jr, et al. Facial plastic and recon-  structive surgery. In: Papel ID, editor. 4th edn. New York: Thieme;  2016. p. 754-65.   11. Pitt D, Aubin JM. Joseph Lister: father of modern surgery. Can J  Surg. 2012;55(5):E8.   1. Hussain K, Wijetunge DB, Grubnic S, et al. A comprehensive anal- 12. Morin RJ, Tomaselli NL. Interactive dressings and topical agents.    ysis of craniofacial trauma. J Trauma. 1994;36:34. Clin Plast Surg. 2007;34(4):643-58.  2. Key SJ, Thomas DW, Shepherd JP. The management of soft tissue 13, Lionelli GT, Lawrence WT. Wound dressings. Surg Clin.  facial wounds. Br J Oral Maxillofac Surg. 1995;33(2):76-85. 2003;83(3):617-38.  3. Karlson TA. The incidence of hospital-treated facial injuries from 14, Argenta LC, Morykwas MJ. Vacuum-assisted closure: a new  vehicles. J Trauma. 1982;22:303. method for wound control and treatment: clinical experience. Ann  4. Fattahi TT. An overview of facial aesthetic units. J Oral Maxillofac Plast Surg. 1997;38:563-77.  Surg. 2003;61(10):1207-11. ; : : 15. Greaves NS, Iqbal SA, Baguneid M, Bayat A. The role of skin sub-  5. Seddon HJ, Medawar PB, Smith H. Rate of regeneration of periph- stitutes in the management of chronic cutaneous wounds. Wound  eral nerves in man. J Physiol. 1943;102:191-215. Repair Regen. 2013;21(2):194—210.    6. Sunderland S. A classification of peripheral nerve injuries produc-  ing loss of function. Brain. 1951;74:491-516.    Open Access This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.  org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropri-  ate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.   The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in  a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.   Dentoalveolar fracture is defined as a fracture in the bone  surrounding the teeth without any extension to the basal  bones of the maxilla or mandible [1, 2].   Dentoalveolar injuries commonly occur in the age group of  8-12 years. They generally involve teeth, soft tissues, and/or  associated bone. Traumatic dental injuries account for a total  of 92% of maxillofacial injuries of which 92% involves only  the soft tissues and 8% involve the maxillofacial bones [2].   Trauma is the foremost etiological factor that leads to a loss  of significant number of teeth annually. The recent advance-  ments in the field of preventive dentistry as well as the devel-  opment of myriad evidence-based techniques to restore the  lost form and function of teeth have made it possible for the  dental surgeon to successfully facilitate the improvement in  the quality of life of trauma-afflicted patients. Time elapsed  post-trauma plays a major factor in determining the outcome  of the intervention. Apart from reestablishing the premorbid  position of the traumatized tooth in its socket, the goal of the  treatment is directed toward achieving the pre-traumatic  occlusion and intra-arch contour [3].    Electronic Supplementary Material The online version of this chap-  ter (https://doi.org/10.1007/978-98 1-15-1346-6_50) contains supple-  mentary material, which is available to authorized users.    O. A. Shetye (2)  Department of Oral and Maxillofacial Surgery, Goa Dental College  and Hospital, Bambolim, Goa, India    © The Association of Oral and Maxillofacial Surgeons of India 2021    The foundation of diagnosis and management of traumatic  dental injuries solely lies on the pillars of a detailed patient  history and a clinical examination. When, Where, and How  forms the “Trauma Triad” of history taking in traumatic den-  tal injuries [4].    When—Time interval between injury and treatment may  significantly affect the prognosis for cases of pulp expo-  sure, displacement, and avulsion type of injuries.   Where—The place of injury. The chances of the injury get-  ting infected on a playground compared to an injury that  has occurred at home in relatively cleaner surroundings.  The place of injury has medico-legal repercussions if the  assault or accident has occurred at the place of work.  Depending on the cleanliness of the wound, the clinician  can also consider protection against tetanus.   How—This may give an indication of concomitant injuries  like soft tissue injuries secondary to the trauma [5].    History of immediate local measures employed to reduce  the severity of injury helps in eliciting information regarding  the original condition of the injured area [6].   History of any systemic disorders that may interfere with  treatment or post-operative healing including a history of  tetanus vaccination has to be obtained before starting the  treatment [7].   “Outside-in” examination (examining the facial structure  in three concentric rings paying more attention to the inner-  most ring) helps in achieving the desired management proto-  col. Level of consciousness should be assessed prior to the  clinical examination [6].   The potential for aspiration, airway compromise, and  neurosensory deficit warrants the need for a thorough evalu-  ation of all maxillofacial injuries before managing dental  injuries [3].    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1-15-1346-6_50    In a patient with missing tooth fragment or prosthesis,  a chest radiograph and abdominal radiograph may be  helpful in locating the missing structures and their  management. Owing to its anatomic position, the right  bronchus is often the site of foreign body dislodgement  [3, 6].    Clinical examination of the patient has to be divided into the  following subsets [8]:    Asymmetry of the face following trauma could be due to  injury to the facial skeleton or swelling. Areas of ecchymosis  and hematoma may indicate fracture of the underlying osse-  ous structure. Laceration, contusion, and abrasion of the  overlying skin are common with dentoalveolar injuries  (Figs. 50.1, 50.2, and 50.3). Mild antiseptic soap should be  used to clean the extra-oral abrasions or a saline wash can be  used while being careful to not inoculate injury site further  with debris or foreign body [4, 8].    Buccal mucosa lacerations should raise suspicion for a  Stensen’s duct injury. The lips, floor of the mouth, and tongue  are areas which are at a risk of being penetrated or sites for  secondary injuries [3].    Bimanual palpation of the maxillary and mandibular dentition  and evaluation of occlusion should reveal areas of discrepancy  or mobility. The direction of dislocation of the apex of primary  tooth should be diagnosed since these teeth are in close  approximation to the succedaneous teeth. Palpating from the  vestibular approach makes this diagnosis easier. Sublingual  ecchymosis/hematoma (Coleman’s sign) at the floor of the    Fig. 50.1 Mandibular anterior lingually displaced dentoalveolar frac-  ture with degloving vestibular wound and ragged lip lacerations    Fig. 50.2 Maxillary anterior palatally displaced and extruded dentoal-  veolar fracture with associated upper lip injury. Note incisal fractures of  the upper lateral incisors (see also Fig. 50.8)    mouth is suggestive of underlying mandibular fractures. Step  deformity, crepitation, malocclusion, and gingival lacerations  raise suspicion for possible bone defects [7, 9].    Fig. 50.3 Maxillary anterior teeth complete avulsion with associated  upper lip injury    Percussion test is performed with the end of the handle of an  examination mirror. Pain to percussion of a tooth is indica-  tive of damage to the periodontal ligament. Dullness to per-  cussion in one or several adjacent teeth can be indicative of  partially luxated teeth or en bloc fracture of tooth or alveolar  bone. The percussion test should be started on a non-injured  tooth to ensure a reliable response through visual analogue  scale [6, 8].   To evaluate the tooth injury thoroughly, pulp vitality is a  must. A positive response indicates that the pulp is alive,  whereas a negative response indicates that the pulp is dead.  Following injury, the tooth may be in a state of shock and  may give a false response. Hence pulp testing should also be  performed during the subsequent visits to acknowledge the  change in response [5].   Electric vitality testing depends on a number of factors  including the stage of eruption of tooth, the presence of a  restoration or decay, and the ability to isolate the tooth and  keep the area clear of blood and saliva [8].   Laser Doppler flowmetry (LDF) is a relatively new pulp  testing apparatus. It employs a laser beam directed at the    coronal-labial aspect of the pulp which is scattered by pulp  blood cells that in turn produce a Doppler frequency shift.  The fraction of light scattered back is detected and processed  to elicit a signal. The basic theory is that the pulp revascular-  ization process can be monitored. Studies have shown that in  cases in which electrometric tests were negative and LDF  displayed vascular perfusion, the LDF accuracy of pulp  vitality reached 100% [3].   All the teeth should be tested for abnormal mobility both  horizontally and vertically. It should be remembered that pri-  mary teeth undergoing physiologic root resorption and there-  fore always exhibit a certain degree of mobility. The typical  sign of an alveolar fracture is the movement of adjacent teeth  when the mobility of a single tooth is tested [6].   Radiographic examination is essential to determine dam-  age to underlying structures and should include intraoral peri-  apical (IOPA), occlusal, panoramic radiographs (OPG), and  cone-beam computed tomography (CBCT) imaging [3, 4].   If conventional CT imaging is done as part of the trauma  series, fine axial and coronal cuts will also show the dentoal-  veolar injuries (Fig. 50.4)    IOPA radiograph provides vital information about root  fracture and dislocation of teeth. At times it is difficult to  adequately evaluate a fracture on an IOPA radiograph, due to  variations in tube-tooth-film geometry. Post-treatment radio-  graphs can confirm the proper repositioning of avulsed or  luxated tooth into alveolar bone.   Occlusal radiographs provide a larger field of view, and a  steep occlusal exposure is of special value in the diagnosis of  root fracture and lateral luxations with displacement of  crown [8].   OPG is a useful screening tool and can demonstrate frac-  tures of the mandible and maxilla as well as fractures of  alveolar ridges and teeth.   Radiographic evaluation of foreign bodies within soft tis-  sues of the lips and cheeks is done by taking radiographs with  the film placed labial to the alveolus. A reduced radiographic  exposure time (approximately 1/3rd of the normal) is used.   CBCT scanning is extremely useful in diagnosis of maxil-  lofacial, alveolar bone, and teeth fractures with the advantage of  high-resolution three-dimensional images with low radiation.   The etiology of pediatric and adult dentoalveolar injuries  were shown in Box 50.1 and Box 50.2 respectively. Box 50.3  and Box 50.4 represents the classification of alveolar bone  fracture and classification of alveolar bone fracture based on  location and displacement respectively.   Class IV: Multiple fracture lines with combination of  fracture of the dentulous segment    Box 50.5: Classification of Dental Injuries and Surrounding Structure  Classification based on level of involvement [11]    Fig.50.5 (a-c) Clinical images showing tooth (a) intrusion, (b) extrusion, and (c) avulsion    Box 50.6: Management of Intruded Tooth (Fig. 50.6) Box 50.7: Principle of Avulsion  Diangelis et al. [12, 13]    e Primary should not be replanted  rr 75 . ¢ Permanent teeth should be replanted as soon as pos-  sible and stabilized for 7-10 days up to 2 weeks  [14, 15].    e To hold the tooth by its crown and not to touch the  root surface.   e To rinse the tooth immediately with saliva, tap  water or saline solution and reimplant the tooth.   e If the patient cannot replace the tooth, it should be  held in the buccal vestibule (only if patient is fully  conscious).   ¢ Gentle irrigation with saline or gauze soaked with  saline may be employed to remove blood clots or   Association of Oral and Maxillofacial Surgeons of India foreign objects from the surface of the root.    4-8 weeks  (b) RCT using Ca (OH), medicament 2-3 Transportation media for avulsed teeth include  weeks after surgical extrusion  2. In open apex 1. Viaspan: a specialized tissue storage media used when  (a) Wait till the tooth erupts for 3 months transporting liver for transplantation.  (b) Place an orthodontic extruding appliance 2. Hanks balanced salt solution: both hanks solution and  viaspan are physiologic with compatible pH and osmo-  Primary Teeth lality. The relative availability and cost-effective hanks  Treatment is debatable solution makes it medium of choice in storage of avulsed  Immediate extraction of the involved tooth teeth.  or  More conservative approach Commercial products are designed especially for storing  avulsed teeth. It has shelf life of 2 years without refrigeration  (Box 50.9).  50.6.1 Storage and Transportation Media 3. Milk: is a readily available medium. It is the medium of  choice in the absence of hanks balanced salt solution or  If the tooth cannot be reimplanted within 5 min, it should be viaspan. Milk will only prevent further cellular demise  stored in a medium that will maintain its vitality and peri- and is used specifically when the teeth has been outside    odontal ligament fibers [14-16]. the oral cavity for less than 20 min.    4. Saliva: is an excellent transport medium and is as effec-  tive as saline. It does not matter if the tooth is stored in  another person’s saliva.   5. Tap water: has been commonly recommended storage  solution but due its hypotonicity, it leads to rapid cell  lysis and increased inflammation on replantation.   6. Contact lens solution: a compilation of information from  a study Blomlof et al. [17] indicates that Hanks buffered  saline, isotonic saline, and pasteurized bovine milk may  be the most favorable known storage media. If none of  these are available, human saliva or contact lens solution  is acceptable short-term substitute storage liquid.   7. Culture mediums like minimum essential eagles medium  and Dulbecco’s storage media [18] have been used as  they contain amino acids, vitamins, and bicarbonates  that help to maintain the vitality of cells.   8. Propolis: a beehive product which has an excellent anti-  inflammatory and anti-bacterial effect has been used as a  storage medium.   9. Green Tea: its polyphenol derivative have antioxidative,  anti-carcinogenic, anti-mutagenic, anti-inflammatory,  antimicrobial, and antiviral effect.   10. Patients own serum have shown to maintain the vitality  of periodontal ligament cells up to | h.  Morus rubra (red mulberry), egg white, coconut water,  rehydrating solution like Gatorade and ricetral, lens  solution, probiotic solutions, saliva officinalis, honey  milk, and ascorbic acid have been used as a transporta-  tion medium for avulsed tooth.    Traumatically avulsed teeth when out of the mouth for a  short period should be reimplanted as soon as possible.    After normal reattachment, survival is prolonged. Avulsed  teeth which remain out of the mouth for more than 2-3 h  generally resorb rapidly and should not be reimplanted  indiscriminately.   The outcome of replantation depends on the stage of root  development and extra-oral time. If the avulsed tooth has a  closed apex and extra-oral time is less than 60 min (early  replantation), the reimplanted tooth will have the best prog-  nosis. The ideal time to begin root canal treatment is within  10-14 days post-replantation and before splint removal.   There is a statistically significant association between  extirpation within 14 days and an increased likelihood of  successful periodontal healing and prevention of external  inflammatory root resorption.   It is generally agreed that Ca (OH), has a beneficial effect  in the outcome because of its antibacterial properties, ability  to dissolve necrotic tissue, and its ability to prevent or con-  trol inflammatory resorption. The anti-inflammatory and  antibacterial action may decrease root resorption by directly  inhibiting resorptive cells (Box 50.10).    Delayed replantation of avulsed tooth with closed apex has  a poor long-term prognosis. The periodontal ligament gets  necrotic and healing is delayed. The goal of delayed replan-  tation is to promote alveolar bone growth so as to encapsu-  late the reimplanted tooth. The eventual outcome is  ankylosis.   In children below age of 15 years, if ankylosis occurs and  when the infra position of the tooth crown is more than  1 mm, decoronation is recommended to preserve the contour  of the alveolar bone.    Root canal treatment (RCT) can be carried out on a tooth  prior to reimplantation or it can be carried out within 14 days  of reimplantation. The tooth is immersed in 2% sodium fluo-  ride solution for a minimum of 5 min up to 20 min.   Avulsed teeth having open apices and extra-oral time less  than 60 min are also reimplanted and stabilized for 7-10  days and up to 2 weeks. The goal of reimplanting developing  (immature) teeth in children is to allow for possible revascu-  larization of the tooth pulp.   If there is evidence of the pulpal infection or inflamma-  tory response, the pulp should be removed and Ca (OH),  placed immediately, aiming to stimulate apexification and  halt the inflammatory process.   It is believed that delayed replantation of avulsed teeth  with open apices have a poor long-term prognosis. The peri-    Fig. 50.7 (a—c) Shows a case of avulsed upper right central incisor in  a 24-year-old man, which presented after few hours of avulsion. The  tooth was transported in milk by the relatives. A RCT was carried out    odontal ligament gets necrotic and is not expected to heal.  Osseous replacement, resorption, or ankylosis will occur.  Therefore some authors have concluded that such teeth  should not be reimplanted.   The recent guidelines recommend replantation to main-  tain alveolar ridge contour as ankylosed roots get trans-  formed to bone during the remodeling process. RCT can be  performed on the tooth prior to replantation through an open  apex (Fig. 50.7a—c).    Stabilization of an avulsed tooth can be achieved using a  variety of materials like wires, arch bar wired to the teeth,    and the tooth reimplanted and stabilized with wire and composite splint  (a, IOPA showing avulsed incisor; b, IOPA with tooth reimplanted; c,  shows the clinical image after splinting)    orthodontic band and brackets attached by acid etch tech-  nique, combined with orthodontic band and acrylic appli-  ance, or periodontal pack.   They are generally maintained for 7—10 days after replan-  tation to allow gingival reattachment.   Studies by Andreason [20] (1985) have shown that pro-  longed splinting may be inadvisable because it enhances  ankylosis.   The socket should be left undisturbed before replantation.  If the alveolar bone has collapsed, a blunt instrument should  be inserted carefully into the socket in an attempt to reposi-  tion the wall. It should be lightly aspirated if a blood clot is  present.   In general, stabilization for reimplanted teeth is required  for 7-14 days. The periodontal ligament fibers should have  healed sufficiently after the first week to remove the splint.  However, the patient should be advised not to bite directly on  the reimplanted tooth for 3-4 weeks after injury.   A wire of moderate stiffness (round 0.030 in. stainless steel)  is adapted to the facial surface at least one or more stable  teeth on either side of the reimplanted teeth.   The physiologic movement imparted to the reimplanted  tooth during function is increased when fewer teeth are  included in stabilization of the avulsed tooth.   The facial surface of the avulsed and adjacent teeth is acid  etched, and wire is cemented to them with composite.   The wire is generally curved along the middle third of the  labial surface of the teeth. 90° terminal bends toward the gin-  giva are made at the labiodistal angles of the most posterior  teeth to be splinted in order to avoid sharp edges and stabil-  ity. The terminal ends should be about 2 mm long to reduce  the possibility of lateral displacement of the wire [21, 22].    Traumatic dental injuries Splinting period  Subluxation 2 weeks  Extrusive luxation 2 weeks  Avulsion 2 weeks    Open reduction/ raise the flap if reduction not possible  (Fig. 50.9 a, b)    Fig. 50.8 Shows the case in Fig. 50.2, which has undergone closed  reduction and fixation by arch bar. Full intrusion and reduction was not  achieved. The occlusal discrepancy was planned to be corrected later by  RCT and necessary prosthetic work    Fig. 50.9 (a, b) Shows a case of high alveolar process fracture seg-  ment in the maxillary right side with associated split between central  incisors. Under GA, the extruded displaced alveolar segment was repo-  sitioned after placement of split arch bars and bridle wiring between the  central incisors. The segment was fixed with mini plate and screws,  taking care not to injure the tooth roots. Due to root anatomy, only a  single plate was fixed after reduction. Post-operative IMF was given for  2 weeks, for additional stability and to help the healing process    Arch bars (Fig. 50.8)  Loop wiring  Orthodontic bands  Acrylic/metallic splints  Acid etch composite    Model surgery on the plaster models is performed to rec-  reate the normal anatomic relationship of the fractured seg-  ment and allow fabrication of accurate splint [9].    Class I fractures that involve a non-displaced, edentulous  alveolar segment often do not require treatment other than a  soft diet and observation. If there is concern about the stabil-  ity of the fracture during the healing process, stabilization  may be used.   Class II fractures that involve a displaced dentulous seg-  ment and need reduction may require a great deal of force to  realign the fractured segment. Posterior fragments are always  displaced to the lingual area. Large forceps may be helpful to  apply a force suitable to reduce the bony fragment. Reduced  fragments are held in place by MMF or splints.   Class III fractures of a moderately or severely displaced  dentulous segment may be too difficult to reduce adequately.  There may be scant room into which the irregular, displaced  segment needs to be replaced. It may be necessary to burr or  rasp down the displaced segment or the opening in the  remaining bone to successfully reduce the fracture. This is  usually accomplished by use of a power drill with a suitable  size bur or a fine rhinoplasty rasp. The amount of tissue that  is removed should be limited so that the sufficient bone to  bone contact remains for bony union as the fracture heals.  Maintenance of class III fractures in a reduced fashion may  be accomplished with arch bars, MMF, and/or variety of  splints.   Class IV fractures that extend into one or more non alveo-  lar fracture lines are usually less challenging than class I  fractures because (1) the bone segments are larger, (2) the  treatment of the associated fractures gives excellent expo-  sure, and (3) usually no barrier exists to reduction. Plates,  screws, arch bars, MMF, and/or variety of splints may be  used [7].    In MME, wires are passed interdentally between teeth in both  the jaws followed by tightening of these wires together in a  cross arch fashion which serves to stabilize the fracture  segments.    Over the period of last century, MMF techniques have  evolved dramatically, and more recently, many more eas-  ier and effective methods have been introduced like MMF  screws, eyelet wiring, and Erich arch bars to name a few.  Although it is a quick and efficient way of securing MMF,  yet, this technique is criticized for extended periods the  patient needs to be closed mouth, difficulty in maintaining  oral hygiene, lack or deficient nutritional support via oral  route and inability to use this treatment modality in medi-  cally compromised patients like epileptics or in immedi-  ate post-operative period due to increased risk of  aspiration.    A soft stainless steel wire of 0.35—-0.5 mm diameter is uti-  lized and pre-stretched to 10% of its original length to pre-  vent loosening of wire once tightened. Overstretching  beyond this point should be avoided as this will make the  wire brittle and susceptible to breakage.   4. Only half a turn to be given at a time at the end.   5. Once the tail is cut, it is turned and placed into the  inter-proximal embrasures.   6. Once all the wires are in place, move the finger  around the arch bat/wire to check for any sharp  edge/margin/ wire ending.    50.9.6.1 Bridle Wire [26, 27]  First advocated by Hippocrates, bridle wire remains one of  the oldest yet a conventional method of treating mandibular  fractures. This technique represents a temporary way of sta-  bilizing the fractured segments, preventing them from flay-  ing apart.   Advantages include stabilization of the two fractured  segments preventing further damage to the adjacent soft tis-  sues, maintenance of the airway patency (especially advan-    tageous for the fractures of the anterior mandible), decrease  pain, and reducing damage to the neurovascular bundle  from immobilizing the fractured fragments, thereby pre-  venting gross movements and also decreasing muscle  cramping.   Following administration of local anesthesia , a 24—26 gauge  wire is passed around the neck of the teeth adjacent to the  fracture site on either side (Fig. 50.11a). With both ends  being secured in the wire holder (Fig. 50.11b), the fractured  segments are manually reduced anatomically, and the wire is  tightened in a clockwise fashion till further reduction is  achieved (Fig. 50.1 1c), and the fracture is stabilized   [26, 27]  This technique represents an easy and fastest method of  immobilization.    Technique  A 15 cm pre-stretched wire is passed through the interdental  embrasure of the tooth on one side from buccal to lingual.  This wire will pass around the tooth and emerge out buc-  cally through the interdental embrasure from the other side.  Both ends are held together and twisted to achieve a 3 cm  tail (Fig. 50.12a—c). Multiple teeth (at least 5—6) in either  jaw are utilized. Following manual fracture reduction and  placement of teeth with premorbid occlusion, the tails from  opposite arch are twisted together in a cross arch or zigzag  fashion to achieve immobilization (Fig. 50.12d). The cut  ends of the tail are secured into the interdental spaces. Once  all the wires/tails are twisted, complete immobilization is  achieved.   The only drawback of this technique is that, in cases of  broken /loose wire, all the cross arch wires will have to be  removed and redone post placement of twisted wire.    Fig. 50.11 Shows sequential steps bridel wiring. (a) Passing of the wire through the tooth embrasure. (b) Formation of the wire loop assuming  the fracture line is between the two premolars. (c) Twisting of both the ends to stabilize the fracture    Fig. 50.12 (a—d) Shows technique of direct Gilmer wiring. Formation of the loop around the tooth in the lower and upper arch followed by twist-  ing both the wires together in order to achieve MMF    50.9.6.3 Interdental Eyelet Wiring (Ivy Loop  Method) [26, 27] (Video 50.1)   A pre-stretched 26 gauge/0.35 mm diameter wire was made  into an Ivy loop utilizing the middle segment of the wire by  twisting it around a metallic rod of 3 mm diameter. 3-4 turns  are given to achieve adequate stability to the loop. Both the  ends of the wire are then cut in an oblique fashion  (Fig. 50.13a).   Both the ends are passed through the interdental space to  emerge lingually/palatally so that the loop lies buccally  (Fig. 50.13b). Following this, one end of the wire is passed  from distal interdental space of the same tooth to emerge buc-  cally. This same wire is passed through the loop and secured  to the other end of the wire which is passed mesially from the  lingual/palatal side to the buccal side of the adjacent tooth  side (Fig. 50.13c,d) . Both the ends are tightened (Fig. 50.13e),  and the tail end cut short and secured into the dental space  mesially to prevent damage to the adjacent soft tissues.   Stability of the MMF is based on the adequate number of  Ivy loops placed in both the arches and secured.   In the maxillary arch, loops can be placed between two  molars, two premolars, or between lateral incisor and canine  or two central incisors. In the mandibular arch, loops are best  placed between two molars, two premolars, or between lat-  eral incisor and canine.    1. In 1975, Hallam modified the Ivy loop by addition of  another loop proximal to the first for the purpose of liga-  ture/tie wire (Fig. 50.14)   Although an interesting modification yet the disadvan-  tage observed was that due to increase in length and in  patients with short vertical dimension, both the proximal  loops would meet one another making the placement of  MMF extremely difficult.   2. Clove hitch  This technique helps in placement of an Ivy loop in cases  of missing teeth or a single isolated tooth. It is the easiest  way to secure MMF where placement of an arch bar or  any other technique of securing MMF is difficult due to  lack of supporting teeth.   The one end of the wire that has an Ivy loop forms a loop  around the lone-standing tooth (Fig. 50.15a) . Continue the  wire around the tooth forming another loop for the second  time (Fig. 50.15b) . The end of the wire is under the first loop    (Fig. 50.15c), and both the ends of the wire are pulled  together and tightened (Fig. 50.15d).   It was first described by Col. Stout in 1943. It represents an  easy and simple technique which requires minimal instru-  mentation. This technique utilizes multiple loops on the buc-  cal surface of the tooth which can be used for both MMF  using wire as well as elastic traction for the purpose of frac-  ture reduction. One major advantage of this technique is the  use of differential traction force that can be achieved and  applied for fracture reduction before securing it with wires  for MMF.   A 30 cm-long pre-stretched wire is placed on the buccal side  of the teeth with the anterior end placed as anteriorly as pos-  sible while the posterior end extending up to the last tooth to  be used. The wire is passed through the interdental space of  the posterior most teeth and emerged through its mesial side.  The wire is then passed over the buccal wire and passed back  into the same interdental space. A 3 mm diameter rod can be  used parallel to the buccal wire for adequate loop diameter as  well as uniformity of the loop (Fig. 50.16a). Once the wire is  passed back through the same interdental space, it then  emerges out from the mesial interdental space of adjacent  tooth (Fig. 50.16b). This continues till the anterior most teeth  where both the ends of the wire are twisted together, cut, and  placed into the interdental space (Fig. 50.16c,d). Each loop is  then twisted, and loops are made of uniform diameter. In cases  of securing MMF, the loops are turned toward the occlusal  surfaces of the teeth, but in cases of elastic traction, they are  turned in the opposite direction toward the gingiva [27].   This technique needs modification when some teeth are  missing. Herein, once the loop at the mesial end of the tooth  adjacent to the missing tooth is formed, both of the free ends  of the wires are held together and twisted till the distal end of  the next tooth. Once the desired length is achieved, the loop  is again formed at the distal end, and the looping continues  till the anterior most teeth.    Indications  It is an alternative to an arch bar for a fractured mandible that  needs fixation.    Technique  A 25 cm-long wire is passed through the posterior most  tooth in the quadrant to emerge bucally, followed by twist-    Fig. 50.13 Shows steps in Ivy loop technique. (a) Photograph of an molar to emerge buccally. (d) Distal end is passed through the loop on  Ivy loop. (b) Both the ends are held together an passed through the — the buccal side to emerge mesially. (e) Both the ends of the wire are  tooth embrasure of the premolar and molar. (c) One end passed is held together and twisted   passed through the mesial of premolar and other through the distal of    ing the wire up to its full length till the midline (Fig. 50.17a).  Another wire is passed from the opposite quadrant of the  same arch and twisted in a similar manner. Both the ends of  this twisted wire are tightened at the midline after reducing  the fracture segments (Fig. 50.17b,c). Once anatomic  reduction is achieved, additional wires are used to stabilize  this long wires by passing around the embrasures of the  teeth and looping around the wire segment (Fig. 50.17d)  (26, 27].   This technique utilizes a 30 cm-long wire that is bent into  a continuous “W” arcade form as depicted in Fig. 50.18a.  The elevated portion of the arcade acts to form the loop,  whereas the depressed portion adapts to the contour of  the teeth palatally or lingually. The distal end of the wire  arcade is kept long enough so that it will follow the buc-  cal contour of the arch, when it is passed through the  interdental space of the most posterior tooth from lin-  gual/palatal to buccal side. The elevated ends of the    Fig.50.15 Showing clove hitch technique. (a—c) Single loop is passed around the lone-standing tooth followed by second loop under the first one,  pulling both the ends together. (d) Showing clove hitch wiring technique    arcade have a ligature wire attached to it (Fig. 50.18b), wire are held together and twisted (Fig. 50.18f). The  which only suffices the arcade to be pulled through to the loops can be used for both elastic traction and wires for  interdental space to emerge buccally (Fig. 50.18c,d). The securing MMF.   long wire is then passed through this loop (Fig. 50.18e), The disadvantage of this technique is that it is very cum-  and a modified hemostat is used to twist this wire to form bersome and adequate expertise is needed to carry out this  uniform loops. At the mesial end, both the ends of the — technique.    Fig. 50.16 (a, b) Showing continuous or multiple loop wiring tech- cally and looping around the rod. (¢, d) Continuous loops till the mid-  nique, a rod is held parallel to the buccal surface of the teeth, and the __ line are made followed by pulling the buccal rod out to achieve loops  wire is passed through the distal most tooth embrasure to emerge buc-    Fig. 50.17 (a, b) Showing steps in fabrication of Risdon wiring. Distal most tooth is used to loop the wire and twist it. (17c) Showing twisted wire in  the midline. (d, e) Showing wires passed through teeth embrasure to loop around the main wire. (f) Alternate method of securing the long wire    Fig. 50.18 (a, b) Showing fabricated W arcade used in Obwegeser technique. (c) Showing ligature wire pulled from the palatal/lingual side to  buccal side. (d—f) Showing wire from the distal most end passing though the loops to be twisted at the most medial end of the arcade   Commercially available arch bars are usually customized or  prefabricated. In most clinical scenarios, prefabricated arch  bars like Erich’s, Jelenko, Winter’s, or Schuchardt’s suffice  the need for placement.    1. Partially edentulous patients where placement of eyelets  is not an option due to insufficient number of teeth.   3. For alignment of avulsed teeth/displaced dentoalveolar  fracture into proper arch form.   5. Asa part of integrated treatment for suspension for treat-  ment of maxillofacial fractures.   Ideal placement is as close to the interdental spaces, which  are then secured with 26 gauge wire. This close placement  helps to reduce the arch bar to tooth contact and allows for  better adaptability of the arch bar to the arch contour, thereby  reducing loosening of arch bar.   In most cases, arch bars are placed from distal of first  molar, in one quadrant to the other, maintaining a minimum  of two teeth on either side of the fracture line in a dentate  patient.   The wire is passed from one interdental space and moved  around the tooth to emerge buccally from the other side  (Fig. 50.19a). Placement of arch bar by securing it with  wire begins (Fig. 50.19b) usually at the midline and pro-  ceeds posteriorly or from one end (molar) to another  (Fig. 50.19c,d) in order to avoid excess in the center and to  achieve uniformity throughout the length of the arch bar.  The wires are usually twisted in between the cleats and  placed into the interdental space to avoid damage to sur-  rounding soft tissues.   The cleats of the arch bar always face gingivally. MMF is  usually secured using 24 gauze wires in box pattern.   Figure 50.19e is showing a model with upper and lower  arch bar placement secured with wires, while Fig. 50.19f is  showing a clinical photograph of arch bar placement.   ¢ Acts as a tension band, resisting forces acting at the alve-  olar level of the fractured component.   ¢ Multiple vectors can be provided by using elastics and  VW cross bracing in reducing the fracture displacement  to achieve premorbid occlusion.    ¢ One of the major drawbacks is the lack of vertical stop in  the anterior region when an arch bar is used. In the poste-  rior region, the opposing teeth act as a vertical stop for  occluding teeth which isn’t the case with anterior region  as the anterior upper teeth may slide over the lower when  elastics are stretched between the maxillary and mandibu-  lar teeth resulting in extrusion of anterior teeth. This prob-  lem can be circumvented, by drilling a hole using a bur in  the gingival area apical to the mucogingival junction  through the buccal and lingual cortices.    An additional 24 gauze wire is passed from the buccal  side of this hole to emerge lingually. The lingual end of the  wire is then passed through the interdental space of the tooth  to emerge buccally. Both the ends of the wire are then twisted  to prevent extrusion.   In the anterior maxilla, anterior nasal spine can be used  for additional suspension of the arch bar to prevent down-  ward pull exerted by the elastics.   Post reduction of the dentoalveolar fracture, the incisal  edges of the fractured teeth bearing segment will remain  above the normal occlusal plane. This discrepancy can be  corrected by application of apical pressure to this segment  through MMF, circummandibular wiring, suspension from  ANS, lateral piriform, buttress, or using the eye of the max-  illomandibular fixation screw.   by Arthur et al. [29] in 1989 reduced the intra and post-    Screws were modified monocortical self-tapping screws that  were kept at 4-5 mm above the mucosa for subsequent wire    Fig. 50.19 (a—d) Showing technique of arch bar placement. The wire is _ is passed below the arch bar to secure it by twisting. (e) Showing a model  passed through the embrasure or emerge buccally. The wire on the mesial —_ with upper and lower arch bar placement secured with wires. (f) repre-  side of the tooth is passed above the arch bar, where as the distal end wire _ senting a clinical photograph of arch bar placement    splinting. Surgical preparation of the site needed prior to  insertion. They were usually wider in diameter with grooves/  flutes.    Screws were self-drilling or self-tapping screws which were  spool shaped. The central part of the screw head is perforated  with one of two channels perpendicular to its axis aiding in  the passage of ligature wires. The top of the screw heads is  smoothly finished at the contact zone with overlying mucosa.   Clinician should consider fracture location, dentition, sur-  gical exposure, and the quantity of bone for placement of  these IMF screws.   Ideal radiographic images obtained are orthopantomo-  gram and CT axial scan to analyze and plan placement of  these screws.   Sites include anterior vestibule and anterolateral (canine  and premolar regions) as they provide sufficient bone depth,  clearance from adjacent tooth, and easy accessibility. Screws  should be placed above the root apices as subapical place-  ment leads to mucosal overgrowth (Fig. 50.20a—d).   Ideally one screw should be placed on either side of the  fracture line. However, in severely displaced cases, it is    advisable to use multiple screws on either side to achieve  vectors in different directions.   Less incidences of penetrating injuries  Lesser appliances inside the oral cavity  Minimum damage to periodontium  Easy maintenance of oral hygiene    Fig. 50.20 (a—d) Showing clinical steps in placement of MMF screw.  Technique for placement of MMF screws. Marking is done between the  root apices followed by drilling and placement of MMF screw, one in    Dentoalveolar fracture mostly involves teeth, soft  tissues, and associated bones. With the recent advance-  ments in the field of dentistry, the oral and maxillofacial  surgeon can restore the lost form and function of teeth to  facilitate the improvement in quality of life in trauma-  afflicted patients.    Acknowledgments For Figs. 50.1, 50.2, 50.3, 50.4, 50.6, 50.7, 50.8  and 50.9 to Suvy Manuel.    each quadrant. 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Management of a complex dentoalveolar trauma: a case report.  Braz Dent J. 2009;20(3):259-62.   Yamashita D, Cho N. Techniques for maxillomandibular fixation.  In: Atlas of oral and maxillofacial surgery. Vol 1. 2nd edn. Elsevier;  2016. p. 638-44.   McDonald RE, Avery DR, Dean JA, Jones JE. Management of  trauma to the teeth and supporting tissues. In: McDonald and  Avery’s dentistry for the child and adolescent. 9th edn. 2010.  p. 403-42.   Coletti DP. Contemporary maxillofacial fixation technique. In:  Operative oral and maxillofacial surgery. 2nd edn. Medical; 2010.  p. 453-61.   Williams JL, Rowe NL. Mandibular fractures: closed reduction.  In: Rowe and Williams maxillofacial injuries. Vol. 2. 2nd edn.  Churchill Livington; 1995. p. 234-66.   Marunick MT. Closed reduction and Immobilization of condy-  lar fractures with intermaxillary fixation alternative techniques  of Ivy Loops and Molar wafers. In: Atlas of craniofacial trauma.  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Open Access _ This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.  org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropri-  ate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.    The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in    a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.    Road traffic accidents (RTA) are one of the primary etiolo-  gies of craniomaxillofacial fractures. Open reduction and  internal fixation (ORIF) is the most important treatment  modality to restore the compromised form and function.  Adequate reduction and fixation with miniplate osteosynthe-  sis is the essential component of management.    The following are guidelines for internal fixation based  on the four basic principles formulated by AO in 1958.    (A) Anatomic reduction: Fracture reduction and fix-  ation to restore normal anatomy   (B) Stable fixation: Fracture fixation with relative or  absolute stability, as required by the patients  injury and type of fracture   (C) Preservation of blood supply: By gentle reduc-  tion and careful handling along with preservation  of vascularity of soft tissues and the bone   (D) Early and active mobilization: Rehabilitation of  the injured part and the patient as a whole with  early and safe mobilization    A. Yadav (D4!)  Department of Oral & Maxillofacial Surgery, Awadh Dental  College & Hospital, Jamshedpur, Jharkhand, India    © The Association of Oral and Maxillofacial Surgeons of India 2021    1. Plating of fractures can be traced back to 1895 when a    metal plate was first introduced by Lane for internal  fixation. It was abandoned due to its drawback of corro-  sion [1].    introduced plates for fixation, but due to insufficient  strength, their designs were abandoned [1].    began with the treatment of fractures of edentulous man-  dible, as the fractures located in edentulous mandibular  segments were easier to manage.    reduction of fracture ends and maximum stabilization of  fracture area. Simplest way to achieve these goals is to  apply the principles of axial compression of fracture ends.  This principle was first advocated by Belgian Surgeon  Davis in 1994 and later adopted by ASIF (association for  the study of internal fixation).   According to him, there was a need for compression  between the fragments of fractures. He used a plate called  coaptens to achieve this goal, which increased stability and  suppressed interfragmentary motion. The mode of healing  initiated by this is called soudure autogene (autogenous  welding) now known as primary bone healing.    in oral and maxillofacial surgery (OMFS) in edentulous  fractured mandible while performing first compression  osteosynthesis. Self-tightening/automatic MCS plate was  developed by Luhr in 1968. Later, dynamic plates were  advocated for surgery of long bones with subsequent  application in mandibular fractures.    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1-15-1346-6_51    modalities  1881 Glimer On either sides of the fracture, two heavy  rods  1886 Hansmann Retrievable bone plates  1945 Christiansen In mandibular fracture-tantalum plates  1956 Bagby First compression plate  1960 Luhr and Improved mandibular compression plates  Mittlmeir  1969 AO/ASIF Dynamic compression plates (DCP)  1970s Brons and Lag screws  Boeriing  1973 Schmoker and (EDCP) eccentric dynamic compression  Spiessel plates  1973 Michelete Miniplates  1975 Champy Monocortical screws principal for fixation  1977 Luhr Compression plates for the first time in  management of fracture mandible  1977 Spiessel For mandible fracture advocated AO/ASIF  principle  1989 Bos Resorbable plates and screws  1994 Dynamic compression plate with locking  compression plate  2011 Development of locking compression    51.3. Concept of Bone Healing  51.3.1 Secondary Bone Healing (Fig. 51.1)    51.3.1.1 Stage I: Inflammation Induction  Immediately after fracture, hematoma formation occurs;  hematoma plays a vital role in the angiogenesis of the heal-  ing fracture. Subsequently, inflammatory cells, stem cells,  and fibroblasts initiate inflammatory response and enhance  angiogenesis. Cytokines which helps in bone repair are  released in this phase and hematoma is removed. Within 3  days, thin layer of fibrous tissue covers the periosteal surface  of fractured bone. The cortical bone adjacent to fracture site  becomes necrotic which later gets remolded by multinucle-  ated osteoclast.   Dense fibrous tissue, cartilage, and fibrocartilage formation  occurs due to organization of subperiosteal hematoma; soft  callus is composed of internal (endosteum of marrow cavity  and lining of Haversian canal) and external components  (periosteum and organizing hematoma) and continued pro-  liferation of osteoblasts; fibrocartilaginous tissue begin to    calcify as the periosteal and endosteal circulation develops.  The conversion of chondrocytes to osteocytes occur and the  entire callus is converted to immature woven bone.    51.3.1.3 Stage Ill: Hard Callus Formation  After 3-4 weeks of fracture, the hard callus begins to form  and osseous union of the fractured cortical bone starts.    51.3.1.4 Stage lV: Remodeling  The trabeculae orient themselves in the direction of func-  tional pressures after bone formation.    Healing without callus formation is called as primary bone  healing. When there is direct apposition of cortical bone sur-  faces, contact healing occurs. Osteoclasts widen the  Haversian canals on either side of the fracture and move  toward each other. The cortical bridging occurs in 8 weeks  and is usually completed in 16 weeks. In gap healing also  primary bone healing occurs; gap as wide as 100 um can be  filled with mature lamellar bone (Fig 51.2).    Simple beam mechanics described the traditional bio-  mechanical properties of mandible, which represents com-  pression at inferior border and tensile forces on the superior  border with an applied anterior load (Fig. 51.3). The “neu-  tral axis” is the line of zero stress where the tensile forces  become compressive, and it is approximately at the level  of the inferior alveolar canal. Compression and tension  will be produced in symphysis region due to torsional  forces.   The muscles inserting on the mandible and forces exerted  by these muscles during function, determine the tension and  compression zone in cases of fracture mandible.   The direction of the muscular forces acting on the man-  dible by temporalis, lateral pterygoid, pterygomasseteric  sling, and suprahyoid musculature is shown by arrows in  Fig. 51.4. For successful treatment of facial fractures in the  form of rigid fixation, the understanding of biomechanics of  facial injury is very important.    Fig. 51.1 Fracture healing 1. Hematoma formation 2. Fibrocartilage callus formation    Midface generally does not show muscle forces acting on  them except for zygomatic bone, on which masseter exerts  the primary force which can create notable bony displace-  ment causing inferior and medial displacement especially in  the presence of temporalis fascia disruption (Table 51.2).    Table 51.2 The four articulations of zygoma with their functions in  management of fracture    Frontozygomatic suture Received greatest tensile forces and is  the important site for fixation  Thin bone, least important site for    Zygomaticomaxillary Best site for fixation to counter the force  buttress of masseter muscle  Zygomaticotemporal Least important site for plating    Compressing together the main fragments of a single plane  fracture can result in absolute stability, i.e., the complete  abolition of interfragmentary movement. Interfragmentary  compression in single plane, as in diaphyseal fractures, can  be achieved by exploiting the eccentric loading capabilities  of the dynamic compression family of plates.   The screw is inserted in a neutral mode, and plate was  fixed to the right-hand fragment. In an eccentric (load) mode,  a screw is then inserted into the left-hand fragment. As the  load screw is fully inserted, it engages and slides down the  sloping surface of the plate hole, and the screw and bone  move toward the fracture, compressing it.   If the plate that exerts axial compression is exactly  contoured to the anatomically reduced fracture surface,  there will be some gapping of the opposite cortex when  the plate is tensioned by tightening the load screw. This is  due to the compression being maximal immediately  beneath the plate and not evenly distributed over the  whole area of the fracture plane. The solution to this prob-  lem is to ““overbend” the plate so that its center stands off  1-2 mm from the anatomically reduced fracture surface.  Slight gaping of the cortex will occur directly underneath  the plate when the neutral side plate is applied to the bone.  The tightening of load screw causes tension in the plate  and compresses the fracture evenly across the full diame-  ter of the bone.    A primary lag screw fixation, exerting interfragmentary  compression, can be vulnerable to disruption by physiologi-  cal bending and/or rotational forces. Such a primary fixation  is usually protected by the use of a plate, spanning from one  main fragment to the other—this “neutralizes” the disruptive  forces. All such forces are then transmitted via the plate and  bypass the primary lag screw fixation.    If a body with a fracture is loaded at each end, over a bending  point (fulcrum), tension (distraction) forces are generated,  maximal on the side opposite the fulcrum, and angulation  occurs. However, if an inelastic band, such as a plate, is  anchored to the tension side of the body, same load will gen-  erate compression across the fracture interface. This is  known as the tension band principle.    Commonly used devices used for fixation are wires, staples,  pins, and screws [6].    Most commonly used materials are titantum (Ti-6A1-4V)  and stainless steel (316L). Stainless steel has been used  because of its greater biocompatibility and corrosion resis-  tance. Since 1980 titanium was used in maxillofacial    The internal fixation is defined as the placement of wires,  plates, screws, rods, pins, and other hardware to stabilize the  fracture fragments.   RIF is defined as “bone fixation of any form in which biome-  chanical forces are either countered or used to stabilize the  fragments of fracture and permits loading of bone to permit  active action” [7].   Examples of RIF are the use of bone plates and screws, two  lag screws, and use of reconstruction plate with three screws  on each side of the fracture fragment. Use of long compres-  sion plate is also included in the rigid internal fixation  examples.    Wires Staples Pin Screws  Pneumatically driven Kirschner Cancellous  staples wires screw    Healing: In the rigid internal fixation, no callus formation  is formed during bone healing. The fracture bones heal by a  process of Haversian remodeling. This primary or direct  bone union requires immaculate immobilization between  osseous fragments, i.e., minimum gap between the rigid fixa-  tion. Examples of rigid fixation for fracture mandible are  shown in Fig. 51.5a,b.    It is a kind of fixation that is not strong enough to prevent  interfragmentary motion completely. Thus interfragmentary  motion is the differentiating factor between rigid and non-  rigid fixation. Any mobility between fragments stabilized  through internal fixation on active usage of skeletal structure  signifies nonrigid fixation.    Fig. 51.5 (a, b) Techniques of rigid fixation for mandibular fracture.  (a) Fixation with single miniplate and tension band; (b) fixation with  two miniplates    Transosseous wiring across a fractured mandible is a  good example of nonrigid fixation. The wire is unable to  neutralize torsion/or shear forces and requires other fixa-  tion methods like MMF (maxillomandibular fixation).   Healing: The bone healing that occurs under the condi-  tion of mild mobility between fragments is called as second-  ary bone healing. There is deposition of periosteal callus in  such circumstances, followed by resorption of fragment  peripheries and tissue differentiation through various stages  from fibrous to osseous healing.    Semirigid fixation is based on load-sharing osteosynthesis.  Semirigid fixations include the use of:    titanium 2.3 mm, 2.4 mm, 2.7 mm  2.0 mm miniplating diameters, mandibular  systems reconstruction bone plate    Due to inadequate  bone stock adjacent to  comminuted fractures,  load-sharing plates  should be avoided    (A) Luhr vitallium maxillofacial systems  (I) Mandibular compression screw system  (ID) Mini system  (II) Micro system  (IV) Mandibular reconstruction system  (B) Champy’s system  (C) AO/ASIF maxillofacial implant system  (1) DCP, EDCP  (II) Reconstruction plates  (D) The Wiirzburg titanium system for rigid fixation    In the late 1950s, AO group put forth the tenets which are  followed in traditional plates and screws. This included  exposure of fracture with anatomic reduction and internal  fixation of fracture fragments with the desired result of ana-  tomic bone union [9]. The stability of these plates is achieved  by locking the plates by the screws.   Conventional screw — bone plates system requires plate  to adapt precisely. In the absence of this contact, the tighten-  ing of screw will draw the segments of the bone toward the  plate which results in change of the occlusion and bony  segments.   On the other hand, the locking plate-screw system does  not require the intimate contact of plate to the underlying  bone in all the areas. The screw tightening locks the plate and  thus stabilizes the bone segments without compressing the  bone to the plate. Alteration in reduction is impossible after  screw insertion.   According to Herford and Ellis [10], the locking plate  and screw system are simple to use. Like compression  plate it does not require plate to be compressed to the  bone.   Klotch et al. [11] also concluded that the locking plates  require less time due to less bending and faster application  with good results.    — Threaded locking plate and screw (Conventional)  — Tapered locking screw and plate (New generation)    The threaded locking plate - screw system features cor-  responding machined threads incorporated in both the screw  and plate. Whereas, the tapered locking screw - plate system  has a screw head which is tapered in shape with machined  threads, with the plate either having no machined threads or  a single machined thread incorporated into its design. This  facilitates a more flexible locking mechanism which allows  for screw angulation of upto 10 degrees, in comparison to the  threaded locking system which needs absolute perpendicular  screw placement [12].    The rigid plates with 2.7 mm bicortical screws were intro-  duced by AO/ASIF in 1972 [13].   The main advantage attributed to the non-locking recon-  struction plate, is its “load bearing” principle. Scolozzi and  Richter [14], used the 2.4 mm AO Titanium plates for the  management of mandible fractures, with good outcomes and  very less complications.   They are available in different shapes for specific areas  like angle reconstruction plate (Fig. 51.6), condylar recon-  struction plate (Fig. 51.7), and straight reconstruction plate  with different lengths.   3. Commonly used in comminuted fractures of man-  dible, sometimes in combination with miniplates    The advantages of rigid fixation with grafting include  immediate jaw function and excellent stabilization of graft.  The main disadvantage at the graft site is disuse osteoporosis  or “stress shielding.” This phenomenon occurs when rigid  plates absorb the mandibles functional stress. To protect the  long bones from stress, the plate’s modulus of elasticity will  have to exceed in comparison with the bone to which it is  attached. Osteoporosis and reduction in bone strength are the  result of protection from stress or shielding in long bones [15].    In oral and maxillofacial surgery, Brons and Boeriing intro-  duced lag screw fixation for the first time in 1970. According  to them two lag screws prevent rotational movements of the  fracture fragments in oblique mandibular fractures [16].   The lag screw principle is used whenever two wide contact  surfaces of the bone should be pressed together (for man-  dibular oblique sagittal fractures or onlay graft fixation).    Through the outer cortex or onlay graft, the drilling of the  hole was carried out of the identical diameter to that of screw  so that the screw slips through the outer cortex. The lag screw  drill, which is of the same diameter as the screw, will simul-  taneously create a conical countersink to provide an optimal  fitting of the screw head. The inner cortex is then perforated  with the normal surgical drill, and the screw is inserted. It  grips the inner cortex and, when tightened, exerts great force  to pull the outer segment into close contact with the inner  one. This principle can be used in oblique sagittal mandibu-  lar fractures, with the placement of at least three screws, or in  combination with the plate, lagging only one or two of the  total minimum number of screws (Fig. 51.8).   Lag screw should be selected in patients having sufficient  bone available for placement of two screws; dissolution of  the bone around the screws results in cases of micromotion.  The lag screw should be placed in the direction perpendicu-  lar to the line of fracture to avoid displacement or overriding  during tightening of the screws.    Disadvantages  As the lag screw fixation relies on compression of  bone fragments and if intervening bone is unstable due  to comminution or missing, there will be segment  overriding or fracture gap shortening, resulting in  malocclusion.    51.7.4 Comparison of Lag Screw Fixation  Methods with Different Methods  of Fixations [17-19]    1. Single lag screw with arch bar, without MMF is sufficient  enough in the treatment of anterior mandible indirectly  reducing the cost and requiring less hardware and time of  healing [17].   2. Lag screw fixation and plating showed excellent outcome  in anterior mandible fracture; lag screws technique is dif-  ficult but associated with less postoperative complica-  tions [18].   3. In mandibular angle fracture, the lag screw demonstrates  smaller inter-fragmentary gap in comparison with mini-  plate fixation [19].   4. Lag screw osteosynthesis is more advantageous for ramus  height restoration in comparison with miniplates and  Kirschner wires, in patients with condylar process frac-  tures [20].    Different treatment principles using monocortical miniplates  without axial compression for treatment of mandibular and  midface fractures were introduced, namely, by Michelet  et al. in the late 1960s, which they published in 1973.   Michelet’s work has been elaborated by Champy et al. for  the management of mandibular angle fracture by the use of  intraoral monocortical miniplates. The ideal line of osteo-  synthesis has been followed by Champy for plates fixation  (Fig. 51.9).   It is based on the principle of neutralizing unfavorable  traction strains while at the same time allowing transmission  of favorable compression forces. The biomechanical validity  of Michelet principles was confirmed in a series of multidis-  ciplinary experiments performed in Strasbourg, France,  between 1971 and 1974 [21].    With this type of fixation, there is adequate stability to  allow direct bony union and is called as functionally stable  fixation. There are many fixation techniques used in oral and  maxillofacial surgery (OMFS) which are not rigid fixation  truly but classified as functionally stable fixation.   Plates and screws are made up of pure titanium. The mini-  plates are 2 cm long, 0.9 mm thick, and 6 mm wide. They  had an elastic limit of flexibility between 70 and 80 per  square millimeter, and their rupture point lies between 95  and 110 decanewton (daN) per square millimeter  (Fig. 51.10).    — The miniplates vary in length from 2 to 9 cm with a thick-  ness of 0.9 mm. They come in different lengths such as 2  holes with gap , 3 holes, 4 holes, 6 holes, and 8 holes to 16  holes with gap or continuous plates.   — The four-hole and six-hole plates are available with inter-  mediate spacing.   — A wide variety of pre-shaped plates like L, X, Y, T, and K,  delta shaped, and 3D- and H-shaped plates are also  available. 2.1 mm is the minimum diameter of the hole in  the plate and has a bevel of 30°.   — Available in lengths of 5, 6, 7,9, 11, 13, and 15 mm.   — 2mm is the diameter of the screw with 1.6 core diameter  of thread.    Fig. 51.11 OPG showing fixation with the help of miniplates after  Leefort I and bilateral sagittal split osteotomy    — The screw thread is 10/10, so that one turn of the screw  corresponds to 1 mm penetration into the bone.   — 2.8 mmis the screw head diameter, and it is designed such  that it allows insertion at 30-degree angle with respect to  the plate surface.   The drill has the same diameter as the core of the   — The external or the outer diameter ranges from 0.8 to  2.0 mm. Core diameter of the screw is its internal diame-  ter. The surgical bone screws act by clamping the bone  plate and bone together.    — The pitch of the screw is calculated parallel to the screw  axis from a point on one thread to corresponding point on  the adjacent thread.   — The distance between screw runout and screw head is the  length of the unthreaded shank.   — The distance between screw runout and plate is the length  of the unthreaded shank with plate.   (23, 24, 25]  Self-tapping screw: The screw which is inserted into a pre-  drilled hole without tapping a screw head is the self-tapping  screw.   Self-drilling screw has a drilled-shaped point to cut and  does not require predrilling. Self-drilling screws have several  advantages over the self-tapping such as it does not require  drilling the hole and prevents thermal damage leading to  infection, screw loosening, osteomyelitis, and nonunion. It  also prevents damage to tooth roots and nerves by the use of  drills and also avoids the complications associated with drill  bit fracture.   The monocortical screws are generally used for fixation of  mandibular fractures and after sagittal split osteotomy.  Chug H-IJ et al. [ 26] also concluded that monocortical  screws provide stable fixation. Also chances of damage to  the vital structure like inferior alveolar and lingual nerve  are less with monocortical screws. Bicortical screws are  usually used at the lower border of the mandible for  fixation.    The microplate fixation concept was introduced by Luhr in  1988. They are composed of cobalt, vitallium alloy, and  molybdenum in the percentage of 68%, 27%, and 5 %,  respectively. It has got excellent physical strength and corro-  sion resistance.   The thickness of plate is 0.5 mm, and the diameter of the  screws is 0.8 mm. In all the three dimensions, they can be  contoured and maintained an excellent degree of rigidity for  osseous segment stabilization. They are used in:   . Fractures of infraorbital area  . Fracture of frontal sinus wall  . Reconstruction of the skull   Inspite of its reduced thickness (0.3 mm), micromesh is  remarkably strong. It is available in sizes of 40 by 60 and 60  by 100 mm. Template made of a soft, malleable tin alloy  comes in various sizes. The template is cut to the shape and  size required in the individual case, and then it is contoured  to the bone surface. The actual titantum micromesh is then  cut out with a wire cutter and contoured on the instrument  table reduplicating the individual shape of the template.    The association of osteosynthesis/association for the study  of internal fixation (AO/ASIF) were founded by a group of  15 Swiss surgeons in 1958. The group was led by Maurice  E. Muller; AO/ASIF investigators have documented the bio-  logic basis for the concepts on which rigid fixation tech-  niques are based.   Spiess] applied AO/ASIF concepts of long bone healing  and modified AO/ASIF instrumentations for use in mandible  in the late 1960s and early 1970s.    Compression can be achieved through static or dynamic  means. The two devices that produce static compression are  the self-compression plate and lag screw.    1. The self-compression plate designed by Perren for the  ASIF has been called the dynamic compression plate  (DCP). It generates interfragmentary compression by  spherical guiding principle. The DCP principle causes the  movement of screw in both vertical and horizontal direc-  tion which compresses the fracture segments.   2. Lag screw principle—when the screw is tightened, it  compresses the surface when the screw glides through the  cortex of one fragment and engages the cortex of the  opposite fragment.    The EDCP (eccentric dynamic compression plate) has  outer hole which is oblique causing compression on alveolar  side and longitudinal inner holes creating basal side inter-  fragmental compression. EDCPs eccentric action eliminates  the need for tension band. This plate has most utility for  simple fracture of the posterior region where there are no  teeth available for splinting.   The reconstruction plate is a load-bearing plate and  absorbs the entire functional load. They are designed for use  without the tension band. It is large and reinforced version of  basal stabilization plate. They can be adapted to local bony  contours and are malleable. Depending on the placement of  drill hole, it has two-way DC holes that enable compression  to be applied in either longitudinal direction.    51.7.7.1 Plates  (I) Linear system (compression plates)  (a) DCP plates  (b) EDCP plates  (IJ) Universal systems (reconstruction plates)   These are designed to withstand tensile loading force in the  mandible. In mandibular angle, body, and symphysis  regions, they can be used comfortably. It can be applied  intraorally or through an extraoral incision. It is used with  a tension band. The dynamic compression plate was devel-  oped in 1969.   The DCP has a self-compressing hole design. The holes  are oblong, and the portion of each hole distant from the  fracture has a sloping form or “shoulder.”   Experimental work showed that the flat undersurface of  the DCP interfered with the vascular supply of the underly-  ing cortex onto which it was compressed by the screws. The  concept of “footprint” is the area of undersurface of the plate  in contact with the underlying bone cortex.    Principles of DCP—The sloping shoulder of the DCP  hole has the form of part of an angled cylinder. If a screw is  inserted eccentrically, so that its head on final tightening  slides down the sloping profile of the hole, the screw/bone  unit will be shifted toward the fracture, and the fracture plane  will thereby be compressed. Such a screw is often referred to  as a load screw.   It produces a compressive force via arrangement of eccentric  and centric (axial) plate holes. EDCP are 8 mm wide and  come in four-hole (36 mm long) and six-hole (42 mm long)  lengths. The stainless steel plates are 2 mm thick, and the tita-  nium plate is 2.2 mm thick. At the fractures alveolar side, the  compression has been provided by the 75° angulation. It is  important to place the sloped edge of the angled hole at the  mandibular lower border (if the plate is placed upside down,  it will tend to distract bone edges at the alveolar border). First  central screws are inserted in EDCPs (longitudinal hole  eccentrically away from the fracture) than at the lower bor-  der; screws are placed in the 75-degree oblique holes eccen-  trically and in the last rest of the screws inserted in a neutral  position. When the plates and tension band splint cannot be  used, in those situations EDCP plates are used. The reduction  forceps with pressure splinting are useful initially to reduce  and compress the fragments when applying the EDCP plate.    Use of titanium plates and screws is time-tested for their use  in management of craniofacial fractures. However, it has  many drawbacks including infection, hardware palpation  and visibility, hypersensitivity to temperature changes, and  stress shielding effect. They also interfere with radiographic  examination. Sometimes, metal ions leach out into soft tis-  sues. In view of these complications, bioresorbable implants  were developed hoping to reduce hardware-associated com-  plications as well as the necessity for hardware removal.   The use of bioresorbable fixation devices must be limited  as their mechanical strength is inferior as compared to the  titanium hardware. They can be effectively used in low load-  bearing areas of maxillofacial skeleton like maxilla, zygoma,  and upper regions of face. The bioresorbable system may not  be strong enough to provide adequate stability in mandible  fractures which are comminuted, as it is a load-bearing bone.  It can be used in simple mandibular fractures.   Bioresorbable fixation systems stabilize fracture seg-  ments long enough for fracture healing and union to occur  then dissolve, thereby reducing complications frequently    encountered with metallic hardware such as palpability, vis-  ibility, cold sensitivity, and need for removal. Most com-  monly polylactic acid (PLA) is used in bioresorbable plates.    Complications [28]  1. For allowing the polymer chains to bend without break-  ing, a heat source is required. Also, the working time is  limited to 8-10 s.  Screw insertion requires pretapping the screw.  Increased operative time.  More expensive.  PLA decreases stress shielding compared to LD-DC  plates.    To reduce the stress shielding, reduction in modulus is the  answer to correct the disadvantages of internal fixation. To  improve the healing of the fracture under the plates, the only  solution is to allow micromotion through the fracture site;  the design should be made in such a way that it resists tor-  sional, bending, and shear movements.    The two miniplates are connected by interconnecting cross-  bars which are used as 3D plates. Technically, they are not  three-dimensional structures, but their closed quadrilateral  shape provides stability in all three dimensions.    The management of the facial fracture is very challenging  due to its unique three-dimensional contours and nonlinear-  ity of facial skeleton. The recent development in the software  technology and 3D modeling has revolutionized the treat-  ment. They can be used as an adjunct to the standard preop-  erative preparation.   To reduce the operating time in the operation theater, the  3D models can serve as a template on which pre contouring  of the fixation plates can be done. Custom-designed titanium  implants can be made with the help of 3D printers to get the  accurate fit. They can be preferred over the conventional  implants and reduce the surgical time. The model design and  virtual surgical planning help in constructing the guides  which can be used perioperatively, can design the optimal  approach preoperatively, and can compare the actual out-  come to the virtual design. To reconstruct the multitude of  craniomaxillofacial defects of mandible, zygoma, midface,  and orbit, these technologies are very helpful. 3D modeling  and computer-assisted surgical planning have been very  helpful in managing the complications associated with these  injuries.    Intraoperative imaging is very important in assessing the  reduction and fixation of all maxillofacial fractures, and  according to its feedback, the surgeons can immediately  make corrections of any error that occur during reduction  and fixation, which indirectly reduces the complications and  avoids potential resurgeries. Computed tomography (CT) is  commonly used for the same purpose.    For the treatment of maxillofacial fractures, many fixation  methods have been used with great success. To reestablish  the pre-injury esthetics, the normal masticatory function and  the proper occlusion in cases of such fractures are the main  objectives of the treatment. Maxillomandibular fixation can  be done for the conservative management of such fractures  which can be carried out with the help of arch bars, wiring,  and cap splints and in edentulous patients by gunning splints.  The open reduction and internal fixation can be carried out    with the help of miniplates, microplates, 3D plates, and  reconstruction plates. Different plating systems and wiring  techniques make the management of these maxillofacial  fractures predictable with high success rate.    Acknowledgment Author wishes to thank Dr. Anshul Rai for provid-  ing Figs. 51.6, 51.7, 51.11, and 51.13.    Uhtoff HK, Poitras P, Backman DS. Internal plate fixation of  fracture: short history and recent developments. J Orthop Sci.  2006;11:118—26.    . Fonseca RJ, Walker RV, Barber HD, Powers M, Frost DE. Oral and    . Ehrenfeld M, Manson PN, Prein J, AOCMF. Principles of internal    fixations of craniomaxillofacial skeleton, trauma, & orthognathic  surgery. Basel: Thieme; 2012.    . Rowe NL, William JL. Maxillofacial injuries. Ist edn. New York:    corrective bone surgery. Principles of internal fixation using the  AO/ASIF technique. New York: Springer. p. 101-3.    . Allgéwer M, Spiegel PG. Internal fixation of fractures: evolution of    . Uhthoff HK, Poitras P, Backman DS. Internal plate fixation of   Koval  KJ. Biomechanics of locked plates and screws. J Orthop Trauma  2004; 18:488-93.   Herford AS, Ellis E. Use of a locking reconstruction bone plate/  screw system for mandibular surgery. J Oral Maxillofac Surg.  1998;56:1261.   Klotch DW, Gal TJ, Gal RL. Assessment of plate use for mandibu-  lar reconstruction: Has changing technology made a difference?  Otolaryngol Head Neck Surg. 1999;121:388.   Coletti DP, et al. Comparative analysis of the threaded and  tapered locking reconstruction plates. J Oral Maxillofac Surg.  2007;65:2587-93.    Spiess] B. Rigid internal fixation of fractures of lower jaw. Reconstr  Surg Traumatol. 1972;13:124—40.   Scolozzi P, Richter M. Treatment of severe mandibular fractures using  AO reconstruction plates. J Oral Maxillofac Surg. 2003;61:458-61.  Waris P. Torsional strength of cortical and cancellous bone grafts  after rigid plate fixation. Acta Orthop Scand. 1981;52:249.   Bansal P, Kumar S, Mishra V, Jaiswal Y, Das G. Evaluation of tita-  nium lag screw osteosynthesis in the management of mandibular  fractures. World J Dent. 2017;8(4):3 15-20.   Emam HA, Stevens MR. Can an arch bar replace a second lag screw  in management of anterior mandibular fractures? J Oral Maxillofac  Surg. 2012;70(2):378-83.   Ellis E. Is lag screw fixation superior to plate fixation to treat  fracture of mandibular symphysis? 3rd J Oral Maxillofac Surg.  2012;70(4):875-82.   Schaaf H, et al. Comparison of miniplate versus lag screw osteo-  synthesis for fractures of mandibular angle. Oral Surg Oral Med  Oral Pathol Oral Radiol Endod. 2011;111(1):34-40.   Sugiura T, et al. A comparative evaluation of osteosynthesis with  lag screws, miniplates, or Kirschner wires for mandibular condy-  lar process fractures. J Oral Maxillofac Surg. 2001;59(10):1161-8,  1169-70.   Michelet FX, Deymes J, Dessus B. Osteosynthesis with miniatur-  ized screwed plates in maxillo-facial surgery. J Maxillofac Surg.  1973;1(2):79-84.   You Z-H, et al. Biomechanical properties of small bone screws. J  Oral Maxillofac Surg. 1994;52:1293-302.   Champy M, Lodde JP, Schmitt R, et al. Mandibular osteosynthesis  by miniature screwed plates via the buccal approach. J Maxillofac  Surg. 1978;6:14.   Baumgart FW, Cordey J, Morikawa K, et al. AO/ASIF self-tapping  screws (STS). Injury. 24 (suppl 1):S1.   Heidemann W, Gerlach KL, Grébel KH, et al. Drill free screws:  A new form of osteosynthesis screw. J Craniomaxillofac Surg.  1998;26:163.   Chung H-IJ, et al. Postoperative stability after sagittal split ramus  osteotomies for a mandibular setback with monocortical plate  fixation or bicortical screw fixation. J Oral Maxillofac Surg.  2008;66:446-52.   Yaramchuk MJ, Gruss JS, Manson PN. Rigid fixation of the cranio-  maxillofacial skeleton: Part II: Implant system for rigid fixation of  craniomaxillofacial skeleton.   Cutright DE, Hunsuck EG. The repair of fractures of orbital floor  using biodegradable polylactic acid. Oral Surg. 1972;33:28-34.    Open Access This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.  org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropri-  ate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.    The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in    a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.    A fracture is defined as “A breach in the continuity of bone.”   The mandible which is the only mobile bone of the maxillo-  facial region forms the lower third of the face. Owing to the  prominence of the symphysis of the mandible, it is most vul-  nerable site to be traumatized during the road traffic acci-  dents and, at the same time, most tempting site to be hit  during the assault. Thus, the fractures of the mandible are  one of the most common in maxillofacial area. It also affects  the social life of the patients (Box 52.1).   The bone is formed in the fetus from a fusion of the left  and right mandibular prominences and the point where these  sides join, the mandibular symphysis. Like other symphysis  in the body, this is a midline articulation where the bones are  joined by fibrocartilage, but this articulation fuses together in  early childhood.    Electronic Supplementary Material The online version of this chap-  ter (https://doi.org/10.1007/978-98 1-15-1346-6_52) contains supple-  mentary material, which is available to authorized users.   Department of Dentistry, All India Institute of Medical Sciences,  Bhopal, Madhya Pradesh, India    © The Association of Oral and Maxillofacial Surgeons of India 2021    Box 52.1: General Effect of Mandible Fracture on Social  Life [1]   Hospital and ICU stay results in separation from  family members and friends.   Weight loss (average 5% of total body weight).  Increased mental stress.    The mandible is a horseshoe-shaped only mobile bone of the  facial skeleton. It is the strongest bone with thick cortices.  Symphysis is the most prominent part of mandible, and the  condyles articulate with glenoid fossa of temporal bone. The  inferior alveolar neurovascular bundle passes through the  bone, and in the case of fracture, it may get traumatized and  can lead to hematoma and neurological deficit.    By definition, there are three types of angle as described  below:    1. Clinical angle: It is the junction between the alveolar  bone and ramus at the origin of internal oblique ridge.   2. Surgical angle: It is the junction between body of the  mandible and ramus at the origin of the external oblique  ridge.   3. Anatomical angle or (gonion): It is the junction where  the lower border meets the posterior border of ramus.    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1-15-1346-6_52    Anatomically, mandibular angle is a weaker structure  compared to other anatomic subsites.    e The ramus of the mandible is thin as compared to the  body. Whenever a thick portion of the bone unites  with the thin portion, it constitutes a line of  weakness.   e Further the third molars are located in the angle region,  and when they are impacted, they occupy lot of space in  the bone and undermine it.   e In the case of mesio-angular impaction, the impacted  third molar tooth acts as a wedge and predisposes the  fracture of angle of mandible, if the direction of force is  perpendicular to it.   e The bone grains which are oriented vertically in the  ramus change their course at the angle of mandible as  they enter the body of mandible. This abrupt change in  the course of the bone grains also makes the bone weak.  All these factors make the mandible vulnerable for frac-  ture at this site.    In the canine area, also the mandible is weaker as the canine  has the longest and the strongest root, and it occupies lot of  space in the bone and undermines and weakens it. Thus, the  mandible has a tendency to fracture at this site.    ¢ The symphyseal area is most prominent and most vulner-  able to trauma. There is a compression of the outer cortex  and expansion of the inner cortex, and the fracture will  result when the forces are beyond the limits of the capac-  ity of the bone to withstand them.   e There is a pair of genial tubercles on the lingual cortical  plate in the midline, situated supero-inferiorly, which give  origin to the genioglossus and geniohyoid muscles,  respectively. Whenever there is a bilateral fracture at the  parasymphysis area, the tongue tends to lose its anchor-  age on the bone, and the patient loses control and the  tongue tends to fall back. It is especially true for the  unconscious patient, where the tongue fall blocks the air-  way, and it could be fatal if not prevented.    The general classification of fractures of bone is described in  Table 52.1.    Simple This type of fracture is not exposed to the external   Compound In such type of fractures, the fracture line is exposed   fracture to the external environment. All dentate fractures are  compound fracture as they communicate with the  oral cavity   Compound This type of fracture is a comminuted one which is   fracture that there is no appreciable clinical movement. Such  a fracture is unusual in the mandible and is  commonly seen in the maxilla   fracture bending rather than breaking. It is commonly seen in  children as their bones are more elastic in nature.  This elasticity allows the bone to bend. This type of  fracture is commonly seen in long bones and  mandibular condyle of children    Figure 52.1 highlights the mandibular fracture according to  site of fracture with its incidence [2].    According to the impact on bone, fracture can be classified  as direct fracture and indirect fracture.   During an impact, the force on the cortex results in com-  pression, and the other cortex undergoes tension. If the force  of the impact is more than the compressive and tensile  strength of the bone, the bone fractures.   In a similar fashion, when there is an impact, the point of  application of force gets compressed, and the resultant vec-  tor travels along the bone and applies tensor force on the  point intersected by this vector. The fracture at the site of  impact is called direct fracture, and the fracture at the site  of intersection with the vector is indirect fracture.   For instance, the force applied to the symphysis menti  results in a direct fracture at the symphysis. The vector travels  to the condylar necks bilaterally and induce indirect fractures    Region of the  Symphysis  @©Association of Oral and Maxillofacial Surgeons of India    Fig. 52.1 (a, b) Highlights the mandibular fracture according to site of fracture with its incidence    of subcondylar areas bilaterally, as the condylar necks are  weak. This is called a “tripod fracture” (as the fracture is at 3  points) or “parade ground fracture” or “guardsman’s fracture.”  The later terms are used because these fractures are commonly  seen among soldiers who stand upright on the parade ground  for a long time. When they faint, they fall on their chin result-  ing in symphysis and bilateral condylar neck fractures.    The most common mandible fracture seen in the developed  countries is angle fracture combined with contralateral body  or symphysis of the mandible [3]. Table 52.2 and Figs. 52.2,  52.3, and 52.4 highlight various combinations of direct and  indirect fractures in the mandible.    The fracture fragments are liable to displacement according  to unfavorable muscle pull leading to difficulty in the man-  agement of these displaced fractures. Table 52.3 highlights  various muscles attached to the mandible with their actions.  According to the displacement of fracture fragments due  to muscle pull, the fracture can be classified as:  When viewed from superior aspect:    1. Vertically favorable: When the fracture line is passing  from buccal cortical plate to the lingual cortical plate with  the buccal end lying mesially and the lingual end of the  line lying distally. In such situation the distal fragment  will be drawn closer to the proximal fragment due to the  pull of the medial pterygoid muscle, and the fracture seg-  ments will come closer rather than getting separated in  buccolingual plane, and thus the fracture is called as verti-  cally favorable (Fig. 52.5a).   2. Vertically unfavorable: In this case, the fracture line passes  buccolingually with the buccal end lying mesially. The dis-  tal fragment in this case will be easily viewed from superior  border. The distal fragment in this case will easily get drifted    lingually due to the pull of the medial pterygoid muscle;  thus there will be separation of the fragments in the bucco-  lingual plane due to the unfavorable muscle pull, and the  fracture is said to be vertically unfavorable (Fig. 52.5b).    1. Horizontally favorable: The fracture line runs supero-  inferiorly with its superior end lying posteriorly than its  inferior end. In this situation, the muscle pulls from the  temporalis, masseter muscle will pull the distal segment  superiorly, and the suprahyoid muscles will put the proxi-  mal segment inferiorly, thus drawing both the segments  closer to each other. This type of fracture is called as hori-  zontally favorable fracture (Fig. 52.6a).   2. Horizontally unfavorable: The fracture line runs supero-  inferiorly with its superior end lying anteriorly and the  inferior end lying posteriorly; thus, the muscle pull  becomes unfavorable and drifts the proximal and distal  fracture segments apart. This is described as a horizon-  tally unfavorable fracture (Fig. 52.6b).    Muscle Action Attachment  Masseter-medial Elevators of the Ramus of the  pterygoid mandible mandible  Temporalis Elevators of the Coronoid process of  mandible mandible  Lateral pterygoid Depressors of the _— Ptreygoid fovea  mandible, lateral  movements  Suprahyoid muscles Depressors of the Body and the genial  (digastricus, geniohyoid, mandible tubercles  mylohyoid)    The clinical features of the fractures are described in  Table 52.4 (Figs. 52.7, 52.8, 52.9, 52.10, 52.11, 52.12, 52.13,  and 52.14).    The abnormal mobility at the fracture site can be elicited  by the bimanual palpation. The mandible is grasped on  either side of the suspected fracture line in such a way that  the index finger is on the occlusal surface of the teeth and  the thumbs are on the inferior border. The proximal and  distal segments are moved in supero-inferior and antero-  posterior direction, to elicit abnormal mobility (Fig. 52.15).    When there is a hairline, undisplaced fracture of the mandi-  ble especially at the symphysis or angle or in the subcondy-  lar areas and it is not conspicuous clinically and radiologically,  a compression of the mandible at the symphysis area and  both the sides over the body, using both the palms by the  operator, elicits tenderness which may suggest the fracture  (Fig. 52.16a, b).    As a rule, in orthopedics, the X-ray must be taken in two  planes perpendicular to each other, i.e., in the anteroposterior  and mediolateral. The most common radiographs to detect  fracture of the mandible are:   3. Lateral oblique view is taken for body, angle, ramus, and  subcondylar fractures.    4. Computed tomography (CT) scan (Fig. 52.19) — Radiographs should not be advised unnecessary, and they  5. Digital visual tomography (DVT) (Fig. 52.20) should always be performed after clinical examination  6. Cone beam computed tomography (CBCT) (Fig. 52.21) and after making provisional clinical diagnosis.   — CT, DVT, and CBCT are the most commonly performed their diagnosis; radiographs should help in confirming the   radiographs for the accurate diagnosis of mandibular clinical diagnosis and for the medicolegal record-keeping  fracture. purpose as much as possible.    General symptoms Signs on inspection  Pain Presence of hematoma  (Fig. 52.9)  Swelling (Fig. 52.7) Facial asymmetry  Difficulty in opening Presence of abrasion, contusion, or laceration  mouth (Fig. 52.10)  (Fig. 52.8)  Tenderness over fracture Discoloration of the skin/echymosis  site (Fig. 52.11)  Inability to chew Trismus due to protective myo-spasm  Inability to swallow Limited excursive movements of mandible    1. More than 100-250 deaths occur worldwide from cancer  due to unnecessary radiation from diagnostic radiology as  suggested by Royal College of Radiologists [4]   2. If somehow retreatment is required for the patient, it gen-  erally depends most commonly on the clinical findings  rather than radiographic    Fig. 52.8 Difficulty in mouth opening due to displacement and devia-  tion of fracture    Bergh van den et al. [6] also suggested that postoperative  radiography is not necessary. The advantages of avoiding  postoperative radiographs are:    1. Exposure reduction of patients to ionizing radiation  2. Reduced cost  3. More efficient discharge    Fig. 52.19 Computed tomography (CT) scan demonstrating displaced  left para median fracture    Once the basic Airway, breathing, circulation (ABC) in the  emergency management has been secured, the suturing of the  extra-/intraoral wounds and initial stabilization and immobili-  zation of the fracture fragments are important. Box 52.2 shows  advantages of immobilization of fracture fragments.   It is a type of temporary stabilization and reduction  of the fracture fragments of the dentate segment with  the help of 24- or 26-gauge wires under local  anesthesia.   The wire should be wrapped around two healthy  teeth adjacent to the fracture line; if the tooth adjacent  to the fracture are mobile, the wire should be wrapped  around the second tooth adjacent to the fracture  (Fig. 52.22a, b).   These bandages are commonly used to temporarily  stabilize the fracture of the lower jaw. Small crepe ban-  dages can be used for mandible fracture.   Fig. 52.20 Digital visual tomography (DVT) demonstrating commi- (a) Barrel bandage (Fig. 52.23)  nuted right body fracture (b) Four-tailed bandage (Fig. 52.24)    Fig. 52.22 (a,b) Temporary stabilization of a grossly displaced bilateral body fracture by bridle wiring    _  ©Association of Oral and Maxillofacial Surgeons of India ©Association of Oral and Maxillofacial Surgeons of India    Wiring techniques required use of multiple wires. These wires  cause inadvertent finger puncture to the operator’s fingers and  increases the risk of spread of blood-borne diseases like HIV  and hepatitis. To avoid such complication, Rai [7] recom-  mended the use of dynaplast adhesive tape over all fingertips  before wearing sterile gloves while doing Maxillomandibular  Fixation (MMF) (Fig. 52.25).    52.10.4 Steps in Open Reduction Internal  Fixation (ORIF) of Mandible Fracture   2. Patients can take only liquid diet  3. Difficult to maintain oral hygiene  4. Challenging in partially edentulous  patients   3. Curettage to remove the granulation tissues and irrigation  with normal saline.    According to Dimitroulis [8] MMF is unnecessary in  undisplaced angle fracture if there is a skilled assistant pres-  ent to assist and help manually reduce the fracture fragments  for plating. Author also believes that many undisplaced, sin-  gle fracture of mandible can be fixed without MMF when  two skilled surgeons operate the case.    Various internal fixation techniques were mentioned in the  literature for both symphysis and parasymphysis fractures  [9]. They are enumerated in Table 52.8.   Note: Readers has to refer Chap. 51 on plating systems to  know the principles of osteosynthesis, tension banding, zone  of compression/tension, etc.   Fixation with two miniplates is widely used for the fixa-  tion of symphysis and parasymphysis fractures (Fig. 52.31).  Some authors preferred use of two lag screws (Fig. 52.32a, b)  for the fixation of symphysis fractures, but their uses are less  in comparison to two miniplates because they are technique  sensitive. Three-dimensional plates require less manipulation  and adaptation which indirectly reduce the operating time    Fig. 52.26 (a, b) Extraoral sub mandibular incision and intraoral vestibular incision    Fig. 52.27 Exposure of the fracture site (left paramedian mandible  via vestibular incision)    (Fig. 52.33), but use of it is questionable when fracture frag-  ments are multiple even in isolated symphysis fractures.   Usually, an intraoral approach is preferred for manage-  ment of symphysis and parasymphysis fractures. However, if  an existing laceration or scar is present, it should be utilized  for exposure of fractured segments and subsequent manage-  ment (Fig. 52.34).    2. Plating should be done after the blunt dissection and  retraction of the neurovascular bundle.    3. One miniplate above and another below the mental  nerve used for fixation of parasymphysis fracture  (Fig. 52.35).    The prevalence of angle fractures ranges from 16.5 to 37 %  in the literature. Presence of third molar (3M) increases  the chance of angle fracture by 3.27 times, and class II-B  positions of 3M are the most favorable for angle fracture,  while class I-A act as protective factors [10].    52.10.7.1 Impact of Presence or Absence  of Impacted Mandibular Third Molar  (IM3M) on Angle and Condylar  Fracture    — Presence of IM3M generates a weak area in the mandibu-  lar angle and predisposes the angle region to fracture after  injury; on the other hand, IM3M can decrease the occur-  rence of condylar fracture which is supposed to be the  weakest area of mandible [11].   — Angle fracture is seen most commonly in patients hav-  ing superficially impacted (vs deeply impacted ) third  molars (M3s) [12]. The reason behind this is that the  mandibular strength is derived from maintenance of cor-  tical and not the medullary bone integrity; this cortical  integrity of the external ridge is disrupted by the pres-  ence of superficial impacted M3s which produce the  point of weakness in the mandible and make it more  prone to fractures [13].    ~ ~ Yon  ©Association of Oral and Maxillofacial Surgeons of India   Closed reduction is advisable for patients who are medically  unfit for surgery (due to any reasons) or those who did not  give consent for open reduction internal fixation (ORIF).    1. Intraoral (Fig. )  2. Extraoral (Fig. a)  3. Transbuccal (Fig. )    Intraoral incision is advocated for ORIF with single mini-  plate, but higher infection rate of 13% was reported in com-  parison with 2% when extraoral incision was used for plating.  Marginal mandibular nerve showed weakness in 8% of cases,    9 (a, b) Use of chin retractor in reduction of fracture fragments    3 (a—c) Reduction of the fracture (with the help of bone holding forceps)    and it sometimes has prominent extraoral scarring in patients  treated with extraoral approach [14] .   Sugar [15] concluded that the combined use of transbuc-  cal and intraoral approach is safe and effective than the intra-  oral approach alone for ORIF. Author too prefers the same  approach.   3. At the time of plating, direct visualization of the occlusion  4. Low risk of injury to facial nerve    Position of Trocar Placement [17] (Fig. 52.37) Table 52.8 Various fixation techniques for anterior mandibular  fracture  Gulses et al. described a safe zone to place the trocar in the .  : : : 1. Reconstruction bone plates  form of a triangle created by drawing three lines on the : 5  2. Single strong nonreconstruction bone plate  face. 3. Double miniplates  4. Two lag screws  Line 1: At the lower border of mandible (mandibular line) 5.  Three-dimensional (3D) plate  Line 2: Gonial-canthal line which ran from the gonion to the 6. Segmental arch bar with single large and stronger bone plate   Line 3: Trago-basal line which ran from tragus to the groove Through a small stab incision, a blunt dissection is per-  over the body of the mandible at infero-anterior angle of formed with dissecting scissors till the mandibular perios-  the masseter (at the point of entry of the facial artery over teum is torn and the trocar is placed through the dissected  the body of the mandible) channel.    ee, awl ee a : == 38 :  ©Association of Oral and Maxillofacial Surgeons of India Association of Oral and Maxillofacial Surgeons of India    Fig. 52.35 One miniplate above and another below the mental nerve    Fig. 52.33 Fixation of anterior mandible with three-dimensional plate : -  used for fixation of parasymphysis fracture    internal fixation of angle fracture (Box 52.3) [18]: Box 52.3: Fixation Techniques for Angle Fracture   Al Moraissi [19] in a meta-analysis showed that the inci- 2. Single miniplate on the superior border (Fig. 52.38)  dence of wound infection, dehiscence, hardware failure, 3. Single plate on inferior border   and overall complications were less in patients treated with 4. Two plates, one at superior and another on inferior  one miniplate on external oblique ridge in comparison to border (Fig. 52.39a, b)    — High rate of sequestrectomy, infection, and subsequent done under local anesthesia in a clinic, but two plates  second surgery was more in two-plate technique. commonly required general anesthesia which indirectly  — Fixation with two plates took more time, i.e., average increases the cost and prolonged the hospital stay.  37 min in comparison to an average of 23.5 min in single  miniplate fixation from incision to suturing. Rai et al. [21] also conclude better results with two-plate    — Second plate fixation at inferior border is more difficult fixation. Second miniplate is supposed to increase stability  and requires more experience. and protects the fracture site against torsion and bending.    Fig. 52.39 Fixation of mandibular angle fracture using two miniplates. (a) Clinical picture, (b) orthopantamogram    Fig. 52.40 Fixation of mandibular angle fracture using 3D plate. (a) Clinical picture, (b) orthopantamogram   Levy et al. [22]advocated two-plate fixation superior for  ORIF of angle fracture. According to them two miniplates  provide better stabilization and have reported lowest compli-  cation rate in comparison to any other plating technique.   Wusiman et al. [23] demonstrate that three-dimensional  (3D) miniplates provide better fixation than standard mini-  plates. It also provides simultaneous stabilization of tension  and compression zones with lower incidence of postopera-  tive complications and good results. According to Zix et al.  [24] 1-mm-thick 3D plate is as stable as 2 mm miniplates,    and it offers better bending stability and more resistant to out  of plane movement or torque.   Ellis IM and Ghali [25] used lag screws for treating man-  dibular angle fractures but reported very high incidence of post-  operative infection and bone exposure. Also the fixation of angle  with lag screws is technique sensitive and requires expertise.   Kang and Zide used seven-hole angle plate when  Champy technique is ineffective and more rigid or semirigid  fixation is required [26]. According to them seven-hole angle  plate is fixed through transfacial trocar and stabilized intra-  orally. On the other hand, Champy plate required bending,  lacks rigidity, difficulty in screw hole drilling, inaccurate  centric placement of screws.   The use of postoperative MMF and extraction versus reten-  tion of teeth in the line of fracture did not influence any of the  outcomes [27]. Increase rate of infection by extraction of a  tooth was found in the study by Ellis and Walker in 1994  [28]. However, in another study published in 2002, Ellis [29]  reported an increased incidence of infection if teeth were left  in the line of fracture. Author advocates extraction of 3Ms at  the time of ORIF for better results.    A single four hole with gap miniplate (Fig. 52.41) below the  root apex and the inferior alveolar canal is sufficient for fixa-  tion of body fracture of mandible through the intraoral  approach most of the times, except when a patient is having    Fig. 52.42 Management of mandibular ramus fracture. (a) DVT show-  ing mandibular ramus fracture, (b) fixation using two miniplates, (c)  postoperative orthopantamogram showing fixation of mandibular    Mandibular ramus (MR) fracture occurs rarely and ranked  third least common fracture after alveolar and coronoid  fracture [30]. MR fractures are very rare in isolation. It can  be horizontal or vertical. Its incidence ranges from 0.9 to  5.5% [31]. Isolated ramus fracture can be managed by  closed reduction, but ORIF is the treatment of choice when  it is associated with other maxillofacial fractures. To cor-  rect the facial height when midface is also fractured, the  vertical rami become the only determinant, and re-estab-  lishment of these buttresses is very important before repo-  sitioning the crushed midfacial bones [32] (Fig. 52.42a-—c).   Heslop et al. [33] advocated repositioning of TF if they are  attached to the muscle or periosteum and remove them if  they are very small or detached from the periosteum.   According to Blinder et al. [34] to prevent infection and  preserve vascularization, TF should be unexposed and unre-  duced. TF should be sandwiched between the two fracture  lines by rigid fixation without exposure, and preserving vas-  cularization may be the treatment of choice   TF of bone at the angle region were more often shown to  get infected in comparison to body, symphysis, or parasym-  physis because thick, better vascularized, and more cancel-  lous bone presents in these areas as compared to angle  region. It’s better to remove small fragments in the angle  region to avoid postoperative discomfort.    ramus and midface fractures (blue arrows point to lower border plates  and green arrows point to upper border plates)    It generally occurs in combination with other fracture of the  mandible (Fig. 52.43a), and with zygomatic complex fracture  (commonly with arch) (Fig. 52.43b), rarely does it occur in  isolation. It can be treated by extraoral or intraoral approaches.  Later, having low incidence of facial nerve injury and no  facial scar. Coronoid fracture ranges from 0.6 to 4.7% of all  facial fractures and 1—2.9% of all mandibular fractures [35].  It manifests as [36, 37]:   ¢ Restricted mouth opening, malocclusion, and facial col-  lapse when occurs in association with other facial fractures    52.10.10.1 Indications for Conservative or Open  Reduction of Coronoid Fractures  (Table 52.9)  Conservative management in the form of soft diet and mouth  opening exercises to avoid bony adhesions to the surround-  ing structures [38]. If patients are treated with MMF and  trismus occurs, it can be managed by removal of the coro-  noid process [39].    Over half of the mandibular fractures are bilateral; in the  case of angle fracture, most of the times, it occurs in  combination of contralateral mandibular body and sym-  physis [40]. ORIF is the treatment of choice most of the  times.   Clinical Tip: An MMF screw can be effectively used for  reduction of a bilateral mandibular fracture by placing the  screw in the symphysis region. A wire is passed through the  screw, and the fracture segment can be manipulated for  reduction (Fig. 52.44).    Table 52.9 Indications of closed and open reduction for coronoid  fractures    Fig. 52.43 Coronoid fracture (a) associated with condylar fracture, (b) associated with zygomatic arch    Comminution is defined as presence of multiple fracture  lines in many small pieces within the same area of mandibu-  lar angle, body, ramus, and symphysis [41]. This type of  fracture rarely occurs in the condyle region. In a comminuted  fracture, bone is “crushed, broken, splintered” into number  of pieces, creating multiple small fragments (at least two free  segments of bone) (Fig. 52.45a, b).    Fig. 52.44 Use of MME screw in reduction of bilateral parasymphysis  fracture    To fix small fragments, multiple options are mentioned in  the literature like miniplate, microplate, screws, steel wires,  and absorbable sutures. A fragment larger than 1 cm should  be conserved, reduced, and fixed [42].   Ellis et al. [43] advocated that more complications are  associated with multiple fragment fractures in comparison to  fractures having few segments. Therefore, comminuted frac-  tures need load-bearing fixation.   The bone fragments will not provide buttressing to help  stabilize the fracture; therefore surgeons operating commi-  nuted mandibular fractures having two or more free bone  fragments and/or requiring bone fragment removal should  opt for reconstruction plates. Miniplates can be used when  comminuted mandibular fractures have only one free bone  fragment. Combination of reconstruction and miniplates can  be used when multiple small fragments are there in commi-  nuted mandible fracture (Fig. 52.46). Implants used for fixa-  tion of comminuted fractures are mentioned in Box 52.4.   Use of reconstruction plates required expertise and it is  time-consuming. Sometimes contour is also not favorable    Fig. 52.46 Combination of reconstruction and miniplates in manage-  ment of comminuted fractures    Fig. 52.47 Postoperative elastics for correction of minor occlusal dis-  crepancies (Inter maxillary elastics- IME)    which can create slight malocclusion but can be managed by  postoperative elastics and selective occlusal adjustments  (Fig. 52.47).   Dia et al. [44] used titanium mesh for the treatment of  comminuted mandible fracture with successful results.  According to them mesh required little soft tissue exposure,  had low infection rate, and provides favorable mandibular  morphology.    According to the literature, the incidence of IAN injury was  [45]:    1. 5.4-81.4% before treatment  2. 0.4-91.3% after intervention  3. 0-46.6% after 1 year    The neurosensory testing was done both before and  after the treatment of mandibular fracture in which nerve  injury is suspected. Two-point discrimination and pinprick  testing can be used to assess the level of IAN injury.  Preoperative knowledge of the patient’s IAN position  (based on CT/CBCT) is very important in decision-making  regarding fixation position of the fracture fragments with  miniplates. Plating should be done above or below the  course of IAN. ORIF in the area of IAN takes longer dura-  tion to normalization of sensation, and it ranges from 1  week to 12 months. Postoperative CT/CBCT is mandatory  if operating surgeon suspected the impingement of screw  on the IAN or no relief of sensation after 6 weeks of ORIF  for further management. Surgeons should not hesitate to  redo the surgery in cases of IAN injury by miniplates and  screws.    With old age, the incidence rate of maxillofacial fracture  increases, with mandibular fracture appearing with a greater  frequency. As the age advances, the weakening of the man-  dible occurs due to:    The most common mechanisms of injury in geriatric  patients are [46]:    Fractures of the edentulous mandible pose unique chal-  lenges. Old age itself is a risk factor for poor outcomes fol-  lowing trauma. There are associated comorbidities like  hypertension, diabetes mellitus, dementia, or stroke which  limit the functional capacity of the patient to bear the stress  of surgery and postoperative recovery. Also, the atrophic  mandible has compromised blood supply with little osteo-    mandibular fracture (bucket handle fracture) occurs most  commonly in elderly (Fig. 52.48).    Controversy exists in the treatment of edentulous mandibular  fracture. One school of thought advocated closed reduction,  and another school is in favor of open reduction and internal  fixation. According to Bradley [47] the major blood supply  to the mandible is “sub periosteal Plexus,” and reflection of  periosteum in ORIF may seriously impair vascular supply to  the bone resulting in non-union.    Fig. 52.48 Bilateral mandibular fracture (bucket handle fracture) in  edentulous patients    Controversy again exists in the use of bone grafts in eden-  tulous mandible. Are bone grafts necessary? Answer is not  always. Reconstruction plates (load-bearing plates) can be  used for comminuted fractures and with large defects. Bone  morphogenic proteins and tricalcium phosphate can be used  as alternative to autogenous grafts in patients whom multiple  comorbidities may influence local or systemic outcomes [48].   Few authors advocated extramucosal intraoral plating for  the ORIF of the edentulous mandibular fracture. It preserves  the blood supply to the mucosa and bone, at the same time  provides adequate stability [49, 50].   This technique is opted when the patient’s systemic  condition does not allow for an open surgery. CR can be  accomplished if the mandibular height is at least 30 mm.  It is difficult to achieve CR if the mandibular height is  <10 mm. CR can be accomplished using a preexisting  denture. If there is no denture, gunning splint can be pre-  pared. The denture/splint is used for immobilization and  fixed to the mandible with circum-mandibular wiring  (Fig. 52.49a, b).   This involves use of plates and screws for fixation of  fractures. Options for ORIF include use of miniplates or  larger reconstruction plates. Miniplates are small and    Fig. 52.49 (a) Securing gunning splint by circum-mandibular wiring, (b) MMF with gunning splint in situ    hence require smaller incision. Screws of miniplates are  also small which can easily involve thin fragments.  However, in cases of larger fractures, a load-bearing  reconstruction plate is preferred.  Advantages: Adequate fixation with no/minimum MMF  Disadvantages: Delayed healing with periosteal blood sup-  ply loss    Among all the maxillofacial fractures, the incidence of pedi-  atric facial fracture is 1-15%. After nasal bone fracture, the  second most common fractures in children are mandibular  fracture with an incidence of 5—50% [51]. In mandible, the  condyle is the commonest site of fracture in pediatric patients  followed by symphysis and parasymphysis. The most com-  mon mechanisms of injury in children are [52]:    In children, the developing tooth buds of canine approxi-  mate the lower border of mandible. This creates a stress point  making the mandible susceptible to fracture in this location.  Once the canine erupts, this weak point is reinforced with the  bone and is not weaker than any other regions of the mandi-  ble. This is the reason probably why parasymphysis fracture  is more common in children than adolescents.   With increasing age, the skull-to-face ratio decreases. The  larger cranium shields the smaller middle and lower thirds of  the face from injuries. This prevents mandibular fracture in  small children; however, with increasing age the mandible  becomes more prominent resulting in more injuries to this  region.    The management of pediatric mandibular fractures is  different in comparison to adults due to [53]:    1. Relatively small size of maxillofacial bones  2. Presence of tooth germs   4. Instability of deciduous or mixed dentition  5. Rapid repair process    1. Undisplaced fractures: Managed conservatively  with close observation, soft diet, analgesics, and  activity prevention   2. Fractures with minor malocclusions: A short period  of MMF with the help of bondable buttons and  wires for 7-14 days   3. Malocclusion with displacement of segments:  Closed reduction using cap splint secured to man-  dible by circum-mandibular wiring (Fig. 52.50a—c)   4. Malocclusion with severe displacement requiring  three-dimensional stabilizations: open reduction  and internal fixation    However the absence of teeth due to exfoliation and poor  retention of wires on the deciduous teeth crowns makes the  ligature wire and traditional use of arch bars difficult or  sometimes impossible [54]. In such cases splinting with  acrylic splint retained with circum-mandibular wires remains  a viable option in treatment of pediatric mandibular  fractures.   Cap splints are secured to mandible by circum-mandibular  wiring. Kelsey Fry bone awl is used for this purpose. A wide-  bore needle can also be used for the same (Fig. 52.51a, b).  Intravenous cannula stillete (IVCS) is also mentioned in the  literature for performing circum-mandibular wiring. The  16-gauge IVCS was used instead of conventional awl [55].   However, management of pediatric mandibular fracture  with ORIF is controversial as the fixation of plates may ham-  per the growth and development of jaw. Titanium miniplates  have been successfully used for ORIF, but the implants are to  be removed within 3- to 12-month period [56].   Yerit et al. [57] proposed use of biodegradable plates for  ORIF. These plates should be mechanically strong and must  undergo resorption within a predictable time frame.    The advantages of biodegradable plates (polyglycolic  and poly-L-lactic acid plating system) in comparison  to titanium plates are [58]:    1. Does not require second operation for removal,  indirectly becoming cost-effective and requiring  less hospital visit.   3. Monocortical plates and screws do not cause dam-  age to the tooth buds.    Fig. 52.50 (a) Pediatric mandibular fracture, (b) cap splint secured using circum-mandibular wiring, (c) postoperative orthopantamogram    Fig. 52.51 (a, b) Securing cap splint by circum-mandibular wiring using wide-bore needle    Anterior iliac crest (cancellous or cortico-cancellous) and  fibula (free microvascular reconstruction) are the most com-  monly used sites from where the bone grafts are used for  mandibular reconstruction. All the cases required bone graft-  ing in cases of mandibular fracture treated with ORIF should  be kept in MMF of 4 weeks postoperatively.    Rachmiel et al. [59] advocated two-stage reconstruction of ¢ Predisposing factors:   . Improper reduction and fixation (Fig. 52.53)  . Alcoholic or metabolic disturbances    mandibular bone defect after trauma by bone grafting fol-  lowed by alveolar distraction osteogenesis (ADO). This  modality helps in correction of intermaxillary vertical rela-  tionship and provides sufficient amount of bone for the  placement of dental implants and prosthesis.   e Elastic traction for correction of minor discrepancies in  occlusion (Fig. 52.47).    It indicates that a fracture has healed but in less than  an optimal position.   It may result when bone is shorter than normal,  rotated or twisted in a bad position, or bent.   It may cause pain, joint degeneration, posttraumatic  arthritis, or catching episodes resulting from  instability.    e Maintenance of oral hygiene by oral rinses. -  ¢ Recall visit for review.  e Follow-up appointments and if results are not satisfactory   frequent follow-up required. -  e If patient is not satisfied, plan for retreatment.    It is a type of uncommon complication of  mandibular fracture, with reported incidence of  2.8-3.9% [60].   It is failure of fracture hematoma to become trans-  formed into an osteogenic matrix so that it is con-  verted into non-osteogenic fibrous tissue.  Non-union identified by mobility in all planes after  interval of minimum 10 weeks.   Radiographically no evidence of progressive  decrease in radiolucency at the fracture site and  rounding off of the bones’ end in the later stages.  It can be treated by ORIF by rigid fixation  (load-bearing reconstruction plate and sometimes  in combination with bone graft) (Fig.  52.54a, b).    Fig. 52.54 (a) Non-union due to closed reduction, (b) management of fracture non-union by load-bearing reconstruction plate    Defect > 6 cm  Reconstruction  with vascularized  bone flap in single  stage    52.16.1 Management of Mandibular  Non-union Depending upon the Size  of the Defect (Table 52.10) [61]    Kokosis et al. [62] advocated use of virtual surgical plan-  ning (VSP) with subsequent computer-aided design and  manufacturing in management of acute mandibular trauma  patients.    The advantages of the use of custom titanium plate in  mandibular trauma are:    Computer-assisted surgery (CAS) including computer-aided  design and manufacturing, surgical navigation techniques,  and rapid prototyping (RP) has been used with lot of success  in mandibular reconstruction (refer Chap. 41 of this book).  CAS helps in [63]:   2. Preparation of stereolithographic (STL) models or accu-  rate implantation material    Some Important Facts from Review of Literature  Regarding Mandible Fracture [64, 65]    1. Injuries caused by assaults were more prone to  develop postoperative infection, nerve damage, and  malocclusion.   2. 11.8-fold more likely to have poor radiographic  outcome in patients with comminuted fracture.   3. Dehiscence, nerve injury, and malocclusion occur  more commonly in surgeries taking longer duration.   4. Patients with three or more fractures were 13.8-fold  more likely to develop postoperative trismus in  comparison to single fracture.   5. Chances of complications are more in patients who  took discharge against medical advice.   6. Treatment of isolated mandible fracture can be  safely delayed to allow for more improved resource  distribution and prioritization of more time-depen-  dent interventions.    Case Scenario 1  A male patient reported with a gunshot injury over right side  of face. Patient’s Glassgow coma scale (GCS) was 15/15  with stable vital signs, but the patient has difficulty in breath-  ing. On maxillofacial examination, a gunshot wound was  present over right side of face at the right mandibular angle  region. Deviation of mandible was present on right side with  cross bite on right side and open bite on left side. Tenderness  was present over right mandibular angle region. On palpa-  tion, intersegmental mobility was present over right angle  region.   Investigation: Apart from blood investigation, a CT scan  was performed, and a final diagnosis of comminuted right  mandibular ramus and angle fracture with bullet in situ was  made (Fig. 52.57a).   Management: Patient was subjected to emergency sur-  gery under general anesthesia with a treatment plan of bullet  retrieval, debridement, and open reduction and internal fixa-  tion of fracture. After the anesthesia was induced, patient  preparation was done; the fracture site was exposed through  an extraoral approach. Thorough debridement was done, and  bullet was retrieved in multiple pieces (Fig. 52.57b). The  bone segments which were detached were removed, and the  fracture segments were fixed using a reconstruction plate fol-  lowing achieving occlusion (Fig. 52.57c). The use of bone  graft was eliminated considering the risk of postoperative  infection due to scattering of bullet particles. Moreover, the  fracture site was a nondentate site; hence bone grafting was  not mandatorily indicated for postoperative dental rehabilita-  tion. Figure 52.57d shows postoperative OPG and fixation of  fracture with reconstruction plate (refer Chap. 59 on Gun  shot injuries).    Case Scenario 2  A female patient reported with the chief complaint of diffi-  culty in chewing following operation to treat mandibular frac-  ture. Patient gave a history of fall from height following  which she was operated for ORIF elsewhere. The general  condition of patient was good. On maxillofacial examination,  mandible was deviated on right side with cross bite on right    Fig. 52.57 Case Scenario | (a) DVT showing comminuted right man-  dibular angle and ramus fracture with bullet in situ; (b) retrieved bullet;  (c) bullet retrieval, debridement, and fixation of fracture with recon-    side and open bite with lingualized occlusion on left side  (Fig. 52.58a). Patient provided us with a pretreatment OPG  which revealed right subcondylar with left side mandibular  comminuted body and angle fracture (Fig. b). We sub-  jected the patient to another OPG which revealed improper  fixation of left mandibular body fracture and no fixation of  left angle and right subcondylar fracture (Fig. 8c).   Diagnosis: Malunited left mandibular body, left angle  fracture, and right subcondylar fracture   Management: Patient was subjected to general anesthesia.  Once the anesthesia was induced, patient preparation was    struction plate; (d) postoperative OPG showing fixation of fracture with  reconstruction plate    done, and fracture site was exposed through extraoral incision  for all the fractures. Existing implants were removed which  resulted in removal of few small bone fragments. The frac-  tured and carious teeth were extracted and reduction was done  by MMF. Occlusion was achieved (Fig. 52.58d), and fixation  was performed using two miniplates at subcondylar site and  load-bearing reconstruction plate at the body-angle unit. A  postoperative OPG was done (Fig. 52.58e). Patient was dis-  charged in stable condition. After 6 months, dental rehabilita-  tion was performed for missing teeth by delivering dental  bridge (Fig. f).    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Bell RB. Computer planning and intraoperative navigation in  cranio-maxillofacial surgery. Oral Maxillofac Surg Clin North Am.  2010;22:135.    Open Access This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.  org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropri-  ate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.   The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in  a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.   Maxillofacial surgeons commonly come across a high inci-  dence of condylar fractures in their practice. A French sur-  geon [1] in the eighteenth century described a high propensity  for a narrow portion in the subcondylar region to fracture,  which is acommon occurrence even today. In spite of a com-  mon occurrence, the management has been controversial as  there is no established consensus in the treatment of condylar  fractures. Traditionally closed reduction has been the treat-  ment of choice for condylar fractures and have been treated  by various forms of intermaxillary fixation. With the  improvement in radiographic imaging and biomaterials used  in the fixation, surgical management has gradually found  acceptance as it restores early function.    The mandibular condyle forms a part of the temporoman-  dibular joint which is unique (Box 53.1), and it is made of  the following structures:    Electronic Supplementary Material The online version of this chap-  ter (https://doi.org/10.1007/978-98 1-15-1346-6_53) contains supple-  mentary material, which is available to authorized users.    V. Dhupar   Department of Oral & Maxillofacial Surgery,  Goa Dental College & Hospital, Bambolim, Goa, India    © The Association of Oral and Maxillofacial Surgeons of India 2021   e Itis a ginglymoarthrodial joint, having both a hinge  and a gliding action    The condyle is one of the two processes of the mandible  present on the superior portion of the ramus. The condylar  head is ovoid in shape measuring approximately 15-20 mm  mediolaterally and 8—10 mm anteroposteriorly in dimension  [2]. The mandibular condyle articulates with the glenoid  fossa present in the squamous portion of the temporal bone  to form the temporomandibular joint (Fig. 53.1). Squamous  portion of the temporal bone is as thin as 2 mm as a result;  the condylar processes maybe driven into the middle cranial  fossa following trauma.    The squamous portion of the temporal bone and the condyle  is separated by a dense fibrous connective tissue called the  articular disc. The disc is firmly anchored to the condyle by  the medial and lateral collateral ligaments, and it merges  with the capsule in the periphery. The joint space is divided  into superior and inferior compartments by the disc.    53.2.3 Capsule and Ligaments  The capsule surrounds the TMJ and is reinforced by the    medial and lateral ligaments which connect the mandible to  the temporal bone. The synovial membrane lines the capsule.    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1-15-1346-6_53    This membrane produces synovial fluid which aids in the  lubrication and nourishment of the joint. The lateral ligament  also known as temporomandibular ligament has a horizontal  and an oblique component which stabilizes the joint. The  strength of the lateral ligament may be partly responsible for  the fracture at the neck of condyle just below the insertion of  the ligament [3]. The medial and lateral discal ligaments  which are present inside the capsule are also called collateral  ligaments. These ligaments connect the disc to the poles of  the condyle. In addition to these ligaments, there are two  non-capsular ligaments, namely, sphenomandibular and sty-  lomandibular which may have a limited function.    There are four muscles of mastication, namely, the medial  and lateral pterygoid, masseter, and the temporalis. Lateral  pterygoid is attached to the pterygoid fovea at the condylar  neck and is responsible for the displacement of the condylar  fractures. Change in the direction of resultant forces post  fracture will alter the function of the mandible during vari-  ous excursion movements.    The arterial blood supply to the TMJ is derived from the two  terminal branches of the external carotid artery, namely:    It may be noted that the condyle receives blood supply  from three sources    1. Medullary bone supplied by inferior alveolar artery  2. Overlying periosteum of the condyle  3. Attachment of lateral pterygoid muscle    This may explain the reason for the fractured condyle to  remains viable even after stripping of the periosteum during the  surgical procedure as the lateral pterygoid muscle remains  attached to the fractured fragment [4]. The venous drainage  starts in the retrodiscal plexus which drains into the superficial  temporal and maxillary veins that join to form the retroman-  dibular vein, which in turn drains into the external jugular vein.    It is imperative to understand the innervation of the joint so  as to minimize the complications following fracture of the  mandible and its management. Both the sensory and motor  innervation is encountered while approaching the joint. The  sensory nerves are auriculotemporal, masseteric, and poste-  rior deep temporal. Auriculotemporal nerve crosses the con-  dyle medial to it and lies in contact with the condylar neck  and capsule [5]. It is encountered in the preauricular incision  and may result in postoperative complications.    It is the key nerve that transverses the face, and it is liable for  the motor function of the muscles of facial expression. This  nerve transverses the temporoparietal fascia and finally  divides into five terminal branches in the parotid gland  (Fig. 53.2). Hence all the extraoral approaches for the condy-  lar fractures are designed keeping the facial nerve in mind.  Al-Kayat and Bramley [6] found the nerve was at an average  distance of 20 mm with a range of 8-35 mm from the ante-  rior margin of the auditory canal. This is the reason the pre-  auricular incision is given in the skin crease near the tragus  or placed endurally. The neck of the condyle can be exposed  via the transparotid approach. In this approach the condyle is  reached through the space between the temporozygomatic  and buccocervical trunks of the nerve. This results in a direct  and safe approach to the neck of the condyle. The marginal  mandibular nerve is encountered in the submandibular or  periangular approach. This branch may further subdivide  into two or more branches [7]. As a rule, the submandibular  incision is given 2 cm below the lower border of the mandi-  ble to prevent paresis of the lower lip.    Fig. 53.2 Terminal branches of facial nerve with Al Kayat and  Bramely’s [6] measurements for trunk of facial nerve. (A) .8—3.5 cm,  (B) 2.4-3.5 cm, (C) 1.3 cm    U-shaped mandible supports the condyles on either side.  There are two major movements while opening the mouth,  rotational, and translational which occur in the inferior and  superior compartments, respectively. Mandibular function is  characterised as a class III lever with the joint being the ful-  crum [8]. The musculature applies the force between the  joint and the masticatory load (Fig. 53.3).    Trauma causing condylar fracture was explained by Lindahl  [9]. It is important to understand the pattern as it gives the  type of injury sustained (Fig. 53.4).    1. Kinetic energy derived from the momentum created by  the subject falling on a static object. This is an axial force  which is transmitted to the condyle from the lower border  of the mandible. Fracture can occur at the site of injury  and at the condyles at a higher level. Occluding teeth can-  not reduce the force. May also result in fracture of teeth.   2. Kinetic energy derived from the momentum created by a  moving object against a static subject. Generally noted in  assaults or sport injuries. More or less horizontal forces  will result in a fracture both at the site of impact and at the    © BRISHANK PRATAP  ©Association of Oral and Maxillofacial Surgeons of India    condyle on the opposite side. Fracture is usually at the  base of the condyle.   3. Combination of the above two is seen in a road traffic  accident and may result in more severe injuries.    An external force applied generally gets distributed over  the entire mandible. However these forces result in the frac-  ture of the subcondylar region which is weak and are subject  to tensile stresses. A counter-coup injury is often noted in the  condylar region. This prevents displacement of the condyles  into the middle cranial fossa especially in bilateral fractures  resulting from injuries over the chin.    The signs and symptoms seen following trauma are due to  the functional loss resulting from the disruption of the local  anatomy. Following trauma a protective mechanism is trig-  gered. It is generally expected that due to premature contact  on the fractured side, excessive forces would be generated  during loading of the non-fractured site on mastication.  However, it is noted there is a shift of mean force vector  towards the non-fractured site which results in protecting the  fractured site during biting [10]. This results in neuromuscu-  lar adaptation. An increase in the muscle activity on the non-  fractured side and a decrease of active force on the opposite    side results in this process. Hence most of the masticatory  forces are directed towards the non-fractured site and result-  ing in less neuromuscular adaptation on the fractured site.  Refer to the article by Ellis et al. [8] for a comprehensive  understanding of the biological considerations of fractures of  mandibular condyle.    Following condylar fracture of the mandible, patients adapt  to the injury by compensation mechanism which is divided  as follows:    Intervention by the surgeons either by open or closed reduc-  tion minimizes the dental compensation. It is noted that    there is a decreased masseter activity on the fractured site  transferring load to a non-fractured site. This results in neu-  romuscular adaptation which may also be a protective phe-  nomenon [8]. In case of an open reduction, there is  minimum amount of neuromuscular adaptation. Usually a  closed reduction results in an articulation which is inferior  and anterior to the articular eminence which may limit the  transitional movement. This can be avoided by open reduc-  tion and fixation. Minimum complications have been  reported in the studies evaluating closed reduction in treat-  ment of condylar fractures as pain and mouth opening were  the only criteria which were evaluated. A statistically sig-  nificant reduction in the incidence of malocclusion and lat-  eral deviation on opening, along with an improved  protrusive and laterotrusive movements, were noted in  patients treated with surgical therapy vis-a-vis closed ther-  apy in a recent meta-analysis report [10]. Compared to  closed reduction where skeletal and neuromuscular adapta-  tion is seen, in open reduction only neuromuscular adaption  will take place following treatment.    Condylar fractures can be described as a fracture line above  the mandibular foramen that runs from the posterior border of  the ramus to sigmoid notch or the condylar head (Fig. 53.5).  Literature mentions numerous classifications of condylar frac-  tures. Most classifications described the fracture based on the  anatomical site, displacement, and fracture level, inclined  towards close reduction. With the advancement of imaging  modalities and better understanding of open reduction proce-  dures, classifications which are relevant are discussed.   Various terms describing the condylar fractures have  appeared in the English literature (Fig. 53.6):    In 1927 Wassumund [11] differentiated between the  head and neck fractures of the condyle. Early classification  only described anatomical position but had no relevance in  treatment as it did not document the angulation of displace-  ment or dislocation. Condylar fractures were classified as:    MacLennan [12] was the first to differentiate between  simple bending, displacement, and dislocation fractures of  the condylar process.    Spiess] and Schroll [13]. A classification well accepted  in the European literature, which differentiated between  fractures of the base and neck of the condyle, it also noted  the range of angulation with deviation, displacement, or dis-  location (Fig. 53.7).    e Type I: condylar neck fracture with no associated devia-  tion/displacement    There are numerous modifications of Spiess! and  Scholl classifications and were given over a period of time  as a result subtypes has evolved especially in type V and  VI fractures. Modifications included Rasse [14], Neff  et al. [15], Hlawitschka and Eckelt [16], and Loukota  et al. [17].    e Type A: There is a continuous bony contact within the  glenoid fossa, with a component of the remaining condy-  lar head and the fracture supported with no loss of ramal  height (Fig. 53.8a).   ¢ Type B: Loss of support within the articulating fossa and  with the loss of mandibular ramal height (Fig. 53.8b).   ¢ Type C: The highest portion of the fracture is below the  level of the lateral ligament, as a result there in a loss of  ramal height (Fig. 53.8c).    Fig. 53.6 (a) No displacement. (b) Deviation. (c) Displacement. (d) Dislocation (deviation). (e) Dislocation (displacement)    © BRISHANK PRATAP  @Association of Oral and Maxillofacial Surgeons of India    Lindahl [9] gave the most comprehensive classification.  Although descriptive, it is a complicated classification [9].    (c) Bending/displacement without overlapping  (d) Nondisplaced fracture without deviation  3. Relation between condylar head and fossa  (a) No dislocation  (b) Slight dislocation  (c) Moderate dislocation  (d) Severe and/or complete dislocation  4. Condylar head fracture  (a) Horizontal  (b) Vertical  (c) Compression fracture    e Subcondylar fracture: The fracture line starts at the sig-  moid notch and extends to the posterior border of the  mandible.   ¢ Condylar neck fracture: It is located at the condylar  process which is below the level of the condylar head.   ¢ Condylar head fracture: The majority of the fracture  components or the whole fracture is contained within the  TMJ capsule.    A most common classification of diacapitular fractures  was given by He et al. [18]. The types of fractures that can be  recognized are (Fig. 53.9):    ¢ Type A—Lateral third portion of the condylar head has  the fracture line, and there is reduction of the ramus  height.   e Type B—Central third portion of the condylar head has  the fracture line, and there is no reduction of the ramus  height.   ¢ Type C—Medial third portion of the condylar head has  the fracture line, and there is no reduction of the ramus  height.   ¢ Type M—It is a fracture which is comminuted with mul-  tiple fragments, usually more than three, of the condylar  head.    Fig. 53.9 Classification of diacapitular fractures (Type M not shown in  figure)    Loukota et al. [19] proposed a system of classification for  condylar processes fractures of the mandible. This classifica-  tion was adopted by SOR group which is based on a line A  drawn perpendicular from the lowest portion of the sigmoid  notch to the posterior border of the mandible. This helps in  identifying the anatomy of the mandibular ramus even in  cases following severe trauma. A clarification is also given  on the condylar head fracture, and it clearly defined the term  minimal displacement.    Diacapitular fracture: Starting in the articular surface the  fracture line may extend outside the TMJ capsule  (Fig. 53.10a).   Condylar neck: Major portion of the fracture line which  starts above the line A remains above it (Fig. 53.10b).  Condylar base: Major portion of the fracture line remains  below the line A, and it extends behind the mandibular   Minimal displacement: Less than 10° displacement or  2 mm overlap of the bone edges or both.    Fig. 53.10 (a) Dicapitular fracture. (b) Condylar neck. (¢) Condylar base    e Line 1 runs parallels the posterior border of the mandible  line .   ¢ Line 2 as called the sigmoid notch line runs perpendicular  to line | at the deepest portion the sigmoid notch.   e Line 3 is perpendicular to the first line and is below the  lateral pole of condylar head.   e A line is also drawn half way between the line 2 and line  3 which differentiates between high- and low-neck frac-  tures (Fig. 53.11).    Neff et al. [21] published the Comprehensive AOCMF  Classification System: Condylar Process Fractures. It is a  system that highlights fracture location, identification, dis-  placement, comminution, and dislocation. Location of the  condylar fracture is clearly identified:    ¢ Condylar head: the condylar head reference line runs per-  pendicular to the posterior ramus below the lateral pole of  the condylar head.   ¢ Condylar neck: the sigmoid notch line running through  the deepest point of the sigmoid notch perpendicular to  the ramus line extending superiorly to the condylar head.   ¢ Base of the condylar process: the sigmoid notch line run-  ning through the deepest point of the sigmoid notch per-  pendicular to the ramus line extending inferiorly.    In the early days classification systems for the condylar  fractures were entirely focused in locating the fracture. This  was followed by systems which added the relation of the  condyle with the adjacent structure. Loukota [19] gave a    classification which accurately locates the fracture with ref-  erence to treatment which is a simple classification to  follow.   The aim of classifying the condylar fractures of the  mandible is to locate the type and nature of the fracture  which in turn will give a clear understanding of the nature  of injury. This in turn will help the surgeon make a deci-  sion on the modality of treatment which may be open or  closed.   In the facial skeletal, one of the most common bones to frac-  ture is the mandible. Analysis of the fracture of different ana-  tomical sites of the mandible revealed that there was a  10-40% incidence of condylar fractures [22—24]. Ellis et al.  [25] published a study that showed condyle fractures repre-    sented 29.3% of all mandibular fractures. Zachariades et al.  [26] stated that 72% of the condylar fractures were associ-  ated with other mandibular fractures. Isolated condylar frac-  tures were rare, and occurrence of malocclusion was more  dependent on the site of fracture. Incidence of fractures of  condylar base were 57%, neck 31%, and head 12% as  reported by Maclennan [27]. Incidence of condylar head was  the least with the majority fractures at the condylar base.  Frequency of unilateral fractures is higher than the bilateral  fractures.   The highest incidence of mandibular fractures in males was  20-30 years and females 30-40 years [25] with the male-to-  female ratio 3:1 [26]. Condylar fracture can result from direct  or indirect trauma. The degree, direction, magnitude, and  point of application of force determine the severity of dis-  placement [27]. Personal violence [28] followed by fall [29-  31] is the most common aetiology of condylar fractures.    The patient may show mild to severe signs and symptoms  following a condylar fracture. These are entirely dependent  on the amount of displacement of the fractured fragments.  Condylar fractures infrequently occurred in isolation and are  generally associated with fractures of other sites of the facial  bones. Surgeons may overlook subtle clinical features.    Signs and symptoms:  e Pain and swelling over the preauricular region  e Ecchymosis over the mastoid region  ¢ CSF otorrhea  ¢ Hollowness over the condylar region  ¢ Restricted incisal opening  e Locked mandible   ¢ Open bite due to the loss of vertical height on the contra-  lateral side.   e Affected side deviates on opening and is common because  of the interruption of the action of the lateral pterygoid  muscle.   ¢ Limited laterotrusive movements away from the fractured  side but may be maintained towards the fracture.    e Bilateral loss of vertical height results in anterior open  bite with posterior gagging (Fig. 53.12b).    Condylar fractures can be evaluated by a number of conven-  tional views. A set of two radiographs are usually taken per-  pendicular to each other for optimum evaluation. However  the assessment has become more descriptive with availabil-  ity of specialized radiographs. Various views which can be  taken to evaluate the condylar fracture are as follows  (Fig. 53.13):    Fig. 53.12 Occlusion post condylar fracture. (a) Unilateral condylar fracture of the left. (b) Bilateral condylar fracture    Fig. 53.13 A case of unilateral fracture of the right side of condyle with a left body of mandible. (a) OPG. (b) PA mandible. (c) Coronal view. (d)  Axial view. (e) 3D view of the CT scan    However it may be noted that with conventional radiogra-  phy, very limited information is available. CT scans in the  three plains, namely, coronal, axial, and sagittal, with volu-  metric studies can reveal the true picture of the fracture both  for the terms of evaluation and treatment planning. MRI are  essential to evaluate the disc injuries specially in dislocation  and intracapsular condylar fractures; however MRI are not  taken as a routine practise    Historically there has been no clear agreement among the  surgeons on the line of management of the fractures of the  condyle. The goals of treatment which were enumerated by  Walker [32] (Box 53.2) are well accepted.   e No pain and minimum interincisal distance of  40 mm on opening the mouth.    Absolute  ¢ Condyle displaced into middle cranial fossa  e Not possible to obtain adequate occlusion by closed  reduction  e Lateral capsular displacement of condyle  e Presence of foreign body   ¢ Comminuted midface fracture, prognathic or ret-  rognathic jaws having associated bilateral condylar  fractures    Literature has indicated that closed reduction has been the  treatment of choice. This may be due to the complexities  involved with open reduction. Surgical approach is techni-  cally demanding and associated with complications in inex-  perienced hands. As a result, some centres have exclusively  treated condylar fractures by closed reduction. However as  opposed to closed reduction, a few centres follow a protocol  for management where open reduction is treatment of choice.  Patients managed by surgical treatment have a superior out-  come in term of post-treatment malocclusion, protrusion,  laterotrusion, and lateral deviation during mouth opening.  However, there was a higher infection rate as compared to  non-surgical treatment. However, there is no statistical dif-  ference in post-treatment pain and maximum mouth opening  in the two modalities of management [10]. Management can  be divided as non-operative and operative (Box 53.6).    Some patients can be managed by observations provided  they have a minimal nondisplaced fracture, dentate with a  stable occlusion and having minimum pain. An important  factor is that the patient must be complaint. At the onset of  the treatment, patient must be explained about the possibility  of additional treatment in the form of closed reduction which  may be required.  Protocol followed is as follows:    1. Diet: There is no restriction on the diet; generally a patient  would be restricted to a soft diet in order to avoid pain.   2. Rehabilitation: Patient is instructed to perform exercises  of the jaw such that all the excursion movements are car-  ried out. Goals of rehabilitation are mentioned in the (Box  53.8).    Box 53.5. Indication for Open and Closed Reduction  Fonseca [35] adapted from references [36-43]    Absolute  ¢ Condyle displaced into middle cranial fossa  e Presence of foreign body  e Extracapsular displacement of condyle laterally  e Malocclusion not amenable to closed reduction  (e.g., functional reduction of ramus height)   e Condylar fractures with an unstable base (associ-  ated midface fractures)   e Unstable occlusion generally seen in periodontal  disease, less than three teeth per quadrant   — Approach is determined by:  (i) Surgeon preference  (ii) Fracture location  (iii) Type of fixation    3. Follow-up: Recall visit is scheduled after 1 week. At this  visit progress is recorded. Next visit is scheduled after 2  weeks if the patient is compliant. In case the progress is  not satisfactory frequent follow-up would be required or a  change in treatment plan.    Closed reduction is a misnomer. It is never possible to achieve  anatomic reduction as seen in management of other fractures.  Closed reduction relies on the functional adaptation where a  stable occlusion is achieved. Advantage of this technique is that  it is minimally invasive and may not require hospitalization. It is  entirely possible to carry out the procedure under local anaes-  thesia. However adaptation is never complete in adults as  opposed to children. It may be possible to treat all types of con-  dylar process fractures by this technique, but the surgeon must    1. Maxillomandibular fixation (MMF): Some surgeons pre-  fer period of MMF which may range over 2-6 weeks.  MME can be obtained by using arch bars, Ivy loops, IMF  screws or any other method a surgeon is comfortable;  however method used will depend on the use of elastics or  wires, and MMF may entirely be based on the level of  fracture. The reader is advised to refer Chap. 50 of this  book for details on various wiring and IMF techniques  The lower the fracture, the longer the period of immobili-  zation. In children immobilization may range from 7 to  10 days as there are high chances of developing ankylo-  sis. This is followed by functional treatment.   2. Functional treatment: At times only, functional treat-  ment may be followed. This treatment relies on guiding  elastics and active movements. Elastics are given to  achieve repeatable occlusion. Initially heavy elastics are  placed and then slowly shifted to light elastics. During  the meals elastics are removed. After an initial period of  2-4 weeks, elastics are placed only during the night.  Minimum elastics must be used as the aim is to permit  maximum mobility of the jaw. Functional treatment can  be supported by myofunctional orthodontic treatment  employing activator therapy. Myofunctional therapy  should be started as soon as the mouth opening enables  taking dental impressions.    This modality is technically challenging due to the complex-  ities in terms of anatomy, approach, and fixation. It has been  observed that by achieving anatomical reduction irrespective  of the type of fixation used, it will result in restoring back the  skeletal architecture. This in turn would require only neuro-  muscular adaptation for full recovery of the patient.  According to the reports, this may be the reason for open  management to be superior to the closed [36].   Surgical approaches to the condylar fracture are entirely  dependent on the following factors (Fig. 53.14):   This is an approach most maxillofacial surgeons are  familiar with in their practise popularly known as Risdon  approach. It exposes the base along with the neck of the  condyle. Incision can either be parallel to the lower border  or placed in a skin crease for maximum cosmetic results.  For the condylar, fracture’s incision is extended backward  and upward to give a maximum exposure hence also  referred to as periangular incision. The marginal mandib-  ular nerve is protected by marking the incision 2-3 cm  below the lower border of the mandible. Incision trans-  verses through the skin, subcutaneous fat, and platysma.  A superior platysmal dissection will expose the marginal  mandibular nerve; however this may not be necessary.  After dissection of the platysma, superficial layer of deep  cervical fascia is transected; this may expose the facial  artery and vein. These may be required to be ligated and  reflected superiorly. This will protect the marginal  mandibular nerve. Then pterygomasseteric sling is divided  and periosteum reflected to expose the lower border of the  mandible. This gives an adequate exposure for  osteosynthesis.   A modification of the submandibular/periangular  approach known as the high submandibular approach or  the high cervical transmassetric anteroparotid approach  provides good aesthetics and reduces the chances of dam-  age to the facial nerve [44]. A curved incision measuring  three to five cm in length is placed about | cm from the  angle of mandible [45]. This is followed by layered dis-  section. An avascular pouch is created superiorly, and the  pterygomasseteric sling is identified. Stripping the mas-  seter muscles of its attachments will lead to the exposure  of the fracture [46] (Video 53.2).    © BRISHANK PRATAP  ©Association of Oral and Maxillofacial Surgeons of India    Fig. 53.15 (a) Incision for submandibular/periangular approach. (b) Area exposed marked green in the mandible   Entire posterior border can be exposed via the retromandibu-  lar approach [47]; hence this approach is useful in treating  fracture of the condylar neck and the base. The anatomic  structures encountered in this approach are the main trunk of  the facial nerve and retromandibular vein. It has two main  variations transparotid and retroparotid. In both the variation  marking of the incision is 5-10 mm below the lobule of the  ear, parallel to the posterior border usually 3—4 cm long.   In this approach incision is extends from the skin to the sub-  cutaneous tissue, and it is undermined to reach the parotid  capsule which is divided horizontally between the path of the  buccal and zygomatic branches of the facial nerve. Dissection  is carried out parallel to the direction of the facial nerve  branches, and it is not important to locate the branches.  Pterygomasseteric sling is sectioned, and periosteal flap ele-  vated to expose the posterior border of the mandible.   In this approach parotid gland is lifted rather than transected  to approach the posterior border of the mandible. Incision in  this approach is placed more posterior as compared to transp-  arotid approach as a result exposure is also restricted. After  the parotid fascia is identified, dissection is carried out  behind the gland. The gland is lifted to expose the posterior  border; from here the dissection carried out is the same as the  transparotid approach.    The wound is closed in layers to avoid dead space. Also, the  parotid fascia should be sutured tightly to prevent sialocele  or parotid fistula. Drains can also be placed.   This incision is most commonly used by the surgeons in  the TM joint surgeries. Diacapitular fractures are  approached via this approach [48]. Branches of facial  nerve are involved in this approach along with the super-  ficial temporal artery and vein. Incision is placed along  the crease of the skin following the tragus and helix of the  ear which can be extended in the temple region. This  extension on the temple minimizes traction and prevents  weakness of facial nerve. Incision is carried from the skin  to the subcutaneous tissue till the white glistening tempo-  ral fascia is reached. Root of the zygoma is palpated, and  an oblique incision is given parallel to the frontal branch  of facial nerve. Superficial temporal fascia is incised, and  a periosteal elevator is inserted below the fascia to strip  the periosteum of the zygomatic arch. This will expose the  capsule of the temporomandibular joint. Capsule is incised  in an open method to expose the head of the condyle. The  neck is exposed by doing a subperiosteal dissection.  Closure is done in layers first being the capsule followed  by temporalis fascia, subcutaneous tissue, and the skin.  The main disadvantage of this approach is an unaesthetic  scar. This can be overcome by placing the incision endur-  ally. The scar hides behind the tragus, but it can cause  perichondritis.    Fig. 53.16 (a) Incision for retromandibular approach. (b) Area exposed marked in mandible (dark green, retro parotid exposure; light green,    Fig. 53.17 (a) Preauricular approach incision. (b) Area exposed marked in the mandible   This is an approach which will provide best cosmetic results.  However major disadvantage is that it can result in stenosis of  the external auditory canal. Also, the closure takes a longer  time. Incision runs parallel to postauricular flexure approxi-  mately 3 mm behind it. Skin followed by postauricular mus-  cles and fascia overlying mastoid are incised. External auditory  canal is identified and completely transected at bony cartilagi-  nous junction. Temporalis fascia is identified, and from here  dissection followed is similar to preauricular approach to  expose the condylar head. Closure is done in layers with a  special attention given to the external auditory canal.    After the adequate exposure of the fractured fragments  reduction is achieved under direct vision. If the distal frag-  ment is placed laterally, reduction tends to be easy. However,  in most of the cases, the fragments tend to be displaced  medially resulting from the pull of lateral pterygoid muscle.  A medially displaced fragment must be lateralized before an  attempt is made to reduce the fracture. For easy manipula-  tion, a plate with a single screw is fixed on the distal frag-  ment. This will help in easy lateralization of the distal  fragment and prevent the fragment from slipping back as the  lower end of the plate acts as a rest on the proximal segment.  Before an attempt is made to reduce the fracture, manual  traction is applied to the mandible so that the vertical height    1. Manual digital traction: Thumb is placed on the lower  teeth and fingers support the lower border. Mandible is  pulled in inferior and anterior direction.   2. Bite block: A bite block is placed on the same side of the  condylar fracture in the molar region. This will result in  inferior distraction of the mandible with rotation.   3. Transosseous wire: A transosseous wire can be passed  along the posteroinferior border of the mandible. A trac-  tion is applied on this wire in an inferior and anterior  direction.    Once the fracture is reduced with the help of a clamp in  the lowermost hole of the plate, pressure is applied to keep  the fractured end in place. Figure 53.19a—d shows the  reduction and fixation of a medially displaced condyle  fracture.   In a case where two plates are planned for fixation, the  smaller plate along the anterior border of the condyle is fixed  first with a screw. Once the anterior plate is fixed on the dis-  tal segment, similar steps are followed as mentioned earlier  for single plate for reduction and fixation.    Fig. 53.18 (a) Manual digital reduction. (b) Traction using bite block. (c) Transosseous wiring. (d) Towel clip    2. Bilateral condylar fracture with anterior mandible—In  these cases there can be flaying of the mandible resulting  in increase of transverse dimension of mandible. Anterior  fractures are reduced and fixed taking into consideration  into the lingual reduction. Anterior fractures are fixed  before the posterior.   3. Panfacial trauma—Principal remains the same, mandi-  ble is fixed as mentioned above before the midface frac-  tures are reduced and fixed. This may change depending  on the sequence followed for fixation of panfacial  fractures    53.7.5 Fixation Techniques (Fig. 53.20a—d),  (Case 1: Fig. 53.21a-b),  (Case 2: Fig. 53.22),  (Case 3: Fig. 53.23a-e),  (Case 4: Fig 53.24a-d)    The most significant advances that have taken place in the  management of fracture of condylar process include the  osteosynthesis material and the technique. Fixation with tita-  nium plates and screws has given optimal results when ade-  quate bone, proper site selection with proper techniques    Fig. 53.19 (a) Medially displaced condylar fracture. (b) Fracture lateralized. (c) Distal segment secured with a plate. (d) Fracture reduced    followed [49]. At the time of surgery fixation, technique is  selected based on the following parameters:    1. Fracture morphology  2. Amount of bone available  3. Surgeon preference    Fixation can be in the form of one plate, two plates,  hybrid plates, lag screws, or restorable plates. Studies  have shown that use of two plates is superior to one plate  [40, 50]. Two plates must be used for lower level frac-  tures to overcome tension and stress in the neck region  by placing plates along the anterior and posterior border  in a triangular fashion (Fig. 53.20a—d). In cases where  there is limited bone, available fixation can be done with  heavier single plate. Single plate is fixed along the long  axis of the condyle. There are many types of hybrid  plates available. These are designed to incorporate the  principle of two plates in a single plate. However, this    makes the plates bulky as a result it may be at times dif-  ficult to fix them especially when there is limited bone  available. Irrespective of the type of plate used, there  should be at least two screws on either side of fracture.  Fixation of condylar head is a challenge because of the lim-  ited space available and the fractures are intracapsular. In addi-  tion, there could be multiple small fragments and associated  injury to the disc and the capsule which may be required to be  repaired. Several osteosynthesis techniques are available for  fixation like the mini plates, stainless steel wire, standard lag  screws, resorbable screws, resorbable pins, and cannulated lag  screws (Fig. 53.25). Reduction and fixation of the condylar  head is technically challenging as the small fragments can eas-  ily necrose if stripping of the muscle is done. Use of two lag  screws would be idle as it will prevent the reduced fragments  from displacement during function, but times it may not be  possible to fix two screws due to limited space Table 53.1 [51].  Intraoral endosocpic approach for treatment of condylar  fractures is given in detail in Chap. 54 of this book.    Fi 0 (a) Single plate. (b) Two plates. (c) Lambda plate. (d) Delta plate    Case 1: Fig. 53.21 (a) OPG view showing left condyle fracture (b) Post operative OPG showing single plate fixed via retromandibular transpar-  otid approach    Case 2: Fig. 53.22 (a) Intra operative view showing two plates fixed for condyle fracture via retromandibular transparotid approach. (b) Post  operative radiograph of showing fixation with two plates    Case 3: Fig. 53.23 (a) PA view showing right condyle fracture. (b) Intraoperative view via retromandibular transparotid approach shows the  displaced condyle. (c) Reduction and fixation done with Lambda plate. (d, e) Post operative PA view and OPG showing the fixed Lambda plates   . Full range of movements which are pain free  . Close supervision by the surgeon    The most common fracture seen in the maxillofacial  region in children is fracture of the condylar process [53].  Condyle is unique in children as there is a very thin corti-  cal bone surrounding a highly vascular cancellous bone.  This can result in a comminuted type of fracture also  called mushrooming. Condylar fractures can result in  definitive deformities, both in terms of function as well as    a facial asymmetry in cases of inappropriate treatment.  Intracapsular fractures can result in retardation of growth  [54, 55] or in excessive growth on the fractured site [56].  Remodelling of the condyle is inversely proportional to  age [9, 25, 26]. Children have a better adaptation than the  adults. Adaption in children is skeletal, neuromuscular, as  well as function. In adults only functional adaptation is  seen. For this reason, literature has supported conserva-  tive management of fracture of the condylar process. It is  paramount to rehabilitate the patient with the restoration    4. (a, b) Pre operative PA view and OPG showing fracture left condyle. (c, d) Post operative PA view and OPG showing the fixed    of minimum mouth opening, lateral excursion movement  with stable occlusion. However, a long-term follow-up  showed 50-53% of patients had complaints even though  minor in nature irrespective of the type of treatment car-  ried out [57]. Early mobilization is recommended in chil-  dren below 15 years. Patients are encouraged to be on soft  diet to avoid pain. In cases where an open bite is present,  guiding elastics will help in restoring the occlusion. There  is no concrete evidence of prolonged period of maxillo-  mandibular fixation.    Fig. 53.25 Fixation of the condylar head fracture with lag screw    Case 5: Fig. 53.26 Shows improperly reduced fracture condyle which  has been fixed in a dislocated position of the condyle-arrow points  towards the plate fixed in wrong position    meniscal disruption and lack of physiotherapy. This  may be seen in comminuted fractures or disruption of  articular disc.    may result in facial asymmetry, occlusal cants, and  reduced ramal height [60]. In adults asymmetry is due  to deviation on opening of the mouth.    arthritic. Factors affecting these are age, long period of  immobilization, capsular, or meniscal injury [61].    Case 6:Fig.53.27 (a) Chronic infection left side condyle region following reduction and fixation, (b) CT scan showed osteomyelitis like changes   e Improvements in imaging (CT scan/MRI) have  resulted in better visualization of fracture site and  understanding of soft tissue injuries along with the  fracture.   e Surgical approaches better understood, and their  application is based on the site of condylar  fracture.   e Importance of anatomic reduction which leads to  early full range of function.   e Need to manage soft tissue injury as and when  need.   e There is an improvements and wide choice of fixa-  tion materials including resorbable materials.    There have been numerous controversies in management of  condylar fractures. They have ranged from which classifica-  tion to use, surgical approach, type of fixation, and outcome  of the treatment. But till date even with all the advances  available to us, we still cannot agree on the two schools of  thought for management of condylar fracture that is closed  or open. Danda et al. [38] concluded in their study that there  was no difference in treatment outcome in both the groups.  This can be debated as it is not possible to compare the two  modalities of treatment in absolute terms. Although it is  pointed out that there are better results in function with open  reduction and fixation, there are inherent complications that  are only seen in cases treated by open reduction [62] such as  nerve injuries and scars.   In an alternative interpretation of evidence, Leon A  Assael [63] opined that both open and closed reduction  have a critical role in management of condylar fractures.  Treatment outcome such as full pain free range of move-  ment and good aesthetics is seen in both the groups.  Malocclusion, functional deficit, and internal derange-  ment are seen irrespective of line of treatment. Over the  years, complications noted in open reduction have reduced  with the better understanding and improvement of tech-  nique, but it can be burden on the patient. These complica-  tions can only be weighed against the functional advantage  patient gets in open reduction and fixation. Treatment of a  condylar fracture will entirely be dependent on multiple  factors.    To conclude it can be safely stated that management of con-  dylar fractures should be patient centric not entirely based on  absolute indications mentioned by various authors. 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Open Access This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.  org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropri-  ate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.   The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in  a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.   The literature is replete with techniques regarding the open  reduction and fixation of the condylar fractures of the man-  dible. The extraoral approach is preferred by the majority of  surgeons in comparison to the intraoral approach.  Nevertheless, open reduction and internal fixation by an  extraoral approach has the evident risk to cause transient or  even permanent facial nerve injury [1—4], leads inevitably to  a facial scar [1, 5], and can course salivary fistulas, sialoceles  [1, 6], Frey syndrome, or disturbance of the great auricular  nerve [1]. In contrast, an intraoral approach is minimizing  these abovementioned risks and facial scars can be avoided  in general [7, 8].   Silverman in 1925 was the first person to mention about  the intraoral approach to condylar fractures [9]. However, at  that time, the surgeons were facing several difficulties treat-  ing those fractures due to a lack of adequate instruments.  Fritzemeier and Bechthold developed the 90-degree angular  screwdriver, and it served as a milestone in the intraoral man-  agement of condylar neck fractures. In their study, there  were 32 fractures of which 2 cases showed early failures.  Other cases during follow-up showed minor deviation from  axis, but there were no evident problems in the temporoman-  dibular joint function [10].   Based thereupon, several authors were reporting about the  use of an intraoral approach treating condylar fractures sur-  gically. Forty-eight cases of displaced and shortened man-  dibular condyle fractures were treated by an intraoral  approach and studied by Mokros and Erle in 1996. In 2/3 of  the treated fractures, the reduction was successful, and no    F. Wilde (X)  Department of Oral and Plastic Maxillofacial Surgery,  Armed Forces Hospital, Ulm, Germany    Department of Oral and Maxillofacial Surgery,  University Hospital, Ulm, Germany  e-mail: frank.wilde @uni-ulm.de    © The Association of Oral and Maxillofacial Surgeons of India 2021   TMJ function was good in 90% of the patients, 43% were  free of symptoms, and 47% had minor dysfunction. The  authors came to the result that proper reduction of the bone  fragments is most important for therapeutic success [11].   Schén et al. [8] compared in a study an intraoral  endoscopy-assisted approach with an extraoral approach for  the treatment of condylar fractures. A reduced risk of facial  nerve damage and no visible scars were the major conclusion  of the study, and they also opined that intraoral endoscopic  approach is a reliable technique for treating condylar frac-  tures [8]. Veras et al. [12] were looking in their study on 25  patients with condylar fractures which were treated surgi-  cally by an intraoral approach. The mean mouth opening  postoperatively was 4.8 cm. Patients postoperatively did not  have clicking of the joint, facial nerve weakness, or pain of  the muscles or the joint. They opined that intraoral reduction  allowed the anatomic ramus height to be restored and that the  functional results were acceptable [12].   Other authors like Jensen et al. [13] or Schneider et al.  [14] were not so enthusiastic about the outcome of surgical-  treated condylar fractures employing an intraoral approach  [13, 14]. Jensen et al. in 2006 stressed on the fact that  intraoral approach for the condylar fractures is very tech-  nically demanding and there is a chance of getting postop-  erative complications [13]. Schneider et al. [14] compared  in a retrospective study 21 fractures which were treated  with an intraoral approach with 24 fractures which were  reduced by an extraoral perimandibular approach. In their  study, the cases treated by intraoral approach showed sub-  optimal radiologic findings, and the patients’ subjective  feelings pointed to less favorable clinical results. They put  forward the suggestion that fractures which do not require  extensive manipulation and fractures which can be reduced  exactly under a limited view only should be approached  intraorally. For all other fractures, they recommend extra-  oral approaches [14].    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1-15-1346-6_54    From the authors’ experience, fractures of the condylar base  and the low and medial part of the condylar process can be  addressed typically by the following described technique.  Treating high condylar neck fractures is demanding and  requires experience in using such an approach. Fractures of  the condylar head or the transition zone between the neck  and head cannot be reached with this approach, and extraoral  incisions are still required when this kind of fractures is get-  ting treated surgically.   For the below-described technique, a team of three sur-  geons (one leading surgeon and two assistant surgeons) are  highly recommended.    To facilitate open reduction and internal fixation of condylar  fractures via an intraoral approach with predictable results,  special equipment is mandatory.   The most important instruments are a 90° angled screw-  driver and drill (Fig. 54.1a). The screwdriver should have  necessarily a sliding screw-holder which facilitates to hold  the screw and plate together (Fig. 54.1b), because position-  ing a plate with one hand and fixing the screw with the  other hand is not appropriate and will lead to unsuccessful  procedures. Self-retaining screwdriver-bits or even self-  tapping screws should be avoided as well. The authors rec-  ommend a straight 90° angled screwdriver with the  aforementioned sliding screw-holder and centric-posi-  tioned screwdriver-bits. Screwdrivers with eccentric-posi-  tioned screwdriver-bits show a lower height indeed.    However, they will lead to tilting of the screwdriver during  the activation of the device, which results in an inadequate  transfer of the force and a frequent loosening of the screws  from the bit.   Besides the 90° angled screwdriver and drill, extra-long  instruments in the form of raspatories and reposition hooks  have to be recommended insistently (Fig. 54.2). They sim-  plify the manipulation and reduction of the fractured condyle  with a good direct view into the operation site. Using stan-  dard configurated instruments results in less vision due to  obstructing the view by the operator’s hands.   An appropriate light-intensive headlight is necessary for  proper illumination of the operation site (Fig. 54.3).   A 4 mm caliber 30° angled endoscope has to be recom-  mended as well. In combination with a special retractor in  which the endoscope can be inserted, a good visualization,  especially of the posterior border of the ramus, can be  achieved (Fig. 54.4).   In addition, a special retractor with a fiber-optic light  guide which can be positioned buccally to the posterior bor-  der of the ramus enables good illumination of the surgical  site (Fig. 54.5). Nevertheless, having an appropriate head-  light, this instrument seems to be dispensable.   It can be further useful to fix the patient during surgery in  a Mayfield head clamp as it is commonly used by the neuro-  surgeons. This allows traction with the retractors without any  movement of the head.   Besides the described instruments, there are several spe-  cial instruments and devices available on the market to  facilitate open reduction and internal fixation using an  intraoral approach. However, from the authors’ experience,  the aforementioned instruments and devices are the most  helpful in treating condylar fractures by an intraoral  approach.    Fig. 54.1 (a) 90° angled screwdriver and drill. (b) Sliding screw-holder which facilitates to hold the screw and plate together (Medartis, Basel,    54 Intraoral Endoscopic Approach for Treatment of Condylar Fractures of the Mandible    Fig.54.2 Extra-long instruments in the form of raspatories and reposi-  tion hooks (Karl Storz, Tuttlingen, Germany)    By extending the standard vestibular incision in a superior  direction along the ascending ramus, the ramus and the con-  dyle region can be exposed intraorally (Fig. 54.6). The  approach is following Obwegeser’s principles of avoiding  visible scars by extending his approach to the mandibular  ramus for sagittal split osteotomy. During the incision of the  oral mucosa, the anatomical course of the buccal nerve has to  be taken into account. The dissection of the mucoperiosteal  flap starts from the mandibular corpus in the region of the  first molar to mandibular angle and far up to the condyle  until the facture line can be explored. To get an appropriate    Fig.54.4 (a) 4mm caliber 30° angled endoscope (asterisk) and retrac-  tor in which the endoscope can be inserted (hash symbol). (b) Retractor  with inserted endoscope (Karl Storz, Tuttlingen, Germany)    Fig. 54.5 Retractor with a fiber-optic light guide (Karl Storz,  Tuttlingen, Germany)    Fig. 54.6 Intraoral approach to the condyle region by extending the  standard vestibular incision in a superior direction up the ascending  ramus    visualization of the condylar neck region, the mucosa includ-  ing the fibers of the temporal muscle had to striped from the  coronoid process up to or even higher than the mandibular  notch. During dissecting the posterior border of the mandib-  ular ramus, the retromandibular vein has to be taken under  consideration. Coagulation in this region has to be done care-  fully, due to the anatomical proximity to the facial nerve  which is running laterally in the parotid gland. This is the  region where the facial nerve may be damaged during the  procedure. In addition to coagulation, vigorous traction can  damage the facial nerve in this location as well.    After dissection to get sufficient access to the condylar neck  region, the displaced condyle has to be identified. The best  instrument for this is the extra-long raspatorium depicted in  Fig. 54.2. During this procedure, the ramus has to be dis-  tracted. This can be performed by pulling the mandible cau-  dally by hand. Another option is to fix one mini-screw in the    Fig. 54.7 After temporary osteotomy and re-fixation of the coronoid  process to get better access for repositioning of medial displaced  condyle    mandibular angle to twist a wire around, which is diverted  out of the skin in the mandibular angle region by a stab inci-  sion. However, this leads to a small extraoral scar.   For this maneuver, a full relaxation of the patient by the  anesthesiologist is recommended. Due to the very low risk  for facial nerve damage employing this approach, this can be  done without increasing this risk.   For medial displaced condyles in high condylar neck frac-  tures, it is sometimes helpful to perform a temporary osteot-  omy of the coronoid process to get better access for  repositioning. A later re-fixation of the osteomized coronoid  process by a miniplate is in theory not needed but recom-  mended by the authors (Fig. 54.7).   Once the dislocated fragment is identified, it has to be  repositioned anatomically. MMF cannot be recommended in  all cases. In some cases, it can be helpful to get a stable  reduction during osteosynthesis; however, in most cases,  MMF is not very helpful. This decision has to be made indi-  vidually case by case.   In most cases, the reposition of the proximal fragment is  not stable from the beginning (Fig. 54.8). Therefore, the  authors recommend to drill the first screw hole in the condyle  fragment close to the fracture line in the region of the sig-  moid notch. A four- or five-hole 1.0 mm up to 1.2-mm-thick  miniplate is fixed in this hole with a 5- to 6-mm-long screw  with a diameter of 2.0 mm. The screw should not be tight-  ened completely. Then the reduction of condyle fragment    54 Intraoral Endoscopic Approach for Treatment of Condylar Fractures of the Mandible    Fig. 54.9 Endoscopic view after fixation of a four-hole miniplate close  to the sigmoid notch with two screws adjacent to the fracture line    can be achieved by pulling on the miniplate with one of the  extra-long reposition hooks. By visual control of the reposi-  tioned fragment, the miniplate should now be fixed in the  ramus part of the fracture close to the sigmoid notch by  eccentric drilling of the screw hole for fracture line compres-  sion during screw insertion. After fixing the second screw,  the first screw has to be tightened completely (Fig. 54.9).    Fig. 54.10 Endoscopic view after fixation of a five-hole miniplate at  posterior border with two screws adjacent to the fracture line    Once this is facilitated, often a small gap and flaring can be  identified at the posterior border of the condylar neck. To  close this gap, a second four- to five-hole miniplate has to  be fixed at the posterior border of the condylar neck. Here  also the hole has to be drilled in the condyle fragment close  to the fracture line. First, the plate has to be fixed in this  hole and should be aligned along the posterior border of the  condylar neck respectively the ramus. Again, the screw  should not be tightened completely at this stage. After exact  anatomical reposition of the condyle, the next screw is now  drilled for compression osteosynthesis in the ramus part of  the ramus close the fracture line and immediately fixed  with the fourth screw (Fig. 54.10). The third screw is then  tightened completely to stabilize the fracture. After attain-  ing control of the anatomical correct reposition with the  endoscope or in low condylar neck fractures even with a  simple dental mirror, the other screw holes in both plates  are drilled and fixed, starting with the plate at the posterior  border and ending with plate close to the sigmoid notch.  Figure 54.11 shows the final endoscopic view with the two  plates fixed. Figure 54.12 is illustrating the recommended  sequencing of plate and screw positioning to facilitate open  reduction and internal fixation via an intraoral approach  using two miniplates.   In addition, the authors recommend intraoperative imag-  ing with a 3D C-arm device at the end of the procedure when  available (Fig. 54.13). This allows the intraoperative radio-  logic control and documentation of the reduced fracture and  of the position of the plates in a multiplanar view and enables  an immediate intraoperative correction when the result of the    Fig. 54.11 Endoscopic view after complete fixation of a condylar  neck fracture with two miniplates. One four-hole plate in the region of  the sigmoid notch and a second five-hole miniplate at posterior border    procedure is not satisfactory. This reduces the risk for revi-  sion surgeries considerably [15, 16].   When the result is satisfactory, the intraoral mucosa has to  be closed in the standard way like every intraoral incision.  Even when the fracture is reduced and stabilized with suc-  cess, the authors still recommend a light MMF with elastics  strained over two or four MMF screws or arch bars for  approximately 1 week for slight immobilization and guid-  ance into the proper occlusion. In case of a postoperative  insufficient occlusion, a prolonged functional treatment as in  nonsurgical treated condylar fractures with elastics or an  orthodontic device like an activator or bionator has to be  recommended.    As mentioned before, the author is recommending the usage  of two miniplates. The plate at the posterior border is respon-  sible for the stability primarily, whereas the plate in the  region of the sigmoid notch prevents flaring of the distal  fragment during function additionally.   For osteosynthesis, 1.0-mm up to 1.2-mm-thick mini-  plates can be recommended (Fig. 54.14). It can be favor-  able to use 1.2-mm-thick miniplates at the posterior border  due to stability reasons. The screws should be usually  5-6 mm long with a diameter of 2.0 mm. Locking screws    Fig. 54.12 Recommended sequencing of plate and screw positioning  to facilitate open reduction and internal fixation via an intraoral  approach using two miniplates    are not necessary and should never be used for the screw  holes which are adjacent to the facture line. These holes  should be drilled eccentric to achieve compression at the  facture line. In modern osteosynthesis systems, locking and  non-locking screws can be used with the same plates. Using  such a system, it may be advantageous to use locking  screws for the fracture-distant screw holes. Nevertheless, as  mentioned before, locking screws are not needed in this  technique.   Besides standard miniplates, there is the option for the use  of so-called 3D plates or special designed condylar neck  plates (Fig. 54.15). However, from the authors’ experience,  plating with two miniplates enables the aforementioned suc-  cessive repositioning and fixation of the facture most easily  and leads to sufficient stability.   There are new developments of anatomically preformed  3D condylar neck plates with integrated reposition wings for  the posterior border and the sigmoid notch (Fig. 54.16).  Whether these kinds of plates are beneficial or not has to be  investigated in the future.    54 Intraoral Endoscopic Approach for Treatment of Condylar Fractures of the Mandible 1121    #3 (XT; Axial) #3 (XT; Axia  Sagittal Custom View cee Coronal Custom Vie    Fig. 54.13 Intraoperative imaging with a 3D C-arm device (Ziehm, Erlangen, Germany) at the end of the procedure and multiplanar view of the  surgical result    ©Association of Oral and Maxillofacial Surgeons of India @©Association of Oral and Maxillofacial Surgeons of India    Fig. 54.14 1.0-mm and  1.2-mm-thick standard miniplates Fig. 54.15 3D miniplate (asterisk) and special condylar neck plate  (DePuySynthes, Zuchwil, Switzerland) (hash symbol) (DePuySynthes, Zuchwil, Switzerland)    Fig. 54.16 (a) Anatomically preformed 3D condylar neck plates with  integrated reposition wings for the posterior border and the sigmoid  notch (KLS Martin, Tuttlingen, Germany). (b) Displaced right condylar    There is no much difference in complications by treating  condylar factures via an intraoral approach in comparison to  all other treatment options. Postoperative infection is the  most common complication followed by malocclusion.  Dysfunctional degeneration of the injured joint can lead to  joint clicking, pain, reduced mouth opening, and mandibular  deviation during opening and closing. Even severe arthritis  or condylar resorption can occur up to the total destruction or  loss of the joint. Hardware failure in form of plate fractures  or loosening of screws can be seen occasionally as well.   In addition to the avoidance of any visible extraoral scar,  the biggest advantage in comparison to all extraoral  approaches for surgical treatment of condylar fractures is the  very low complication rate concerning facial nerve injuries,  salivary fistulas, sialoceles, Frey syndrome, or disturbance of  the great auricular nerve.    The described intraoral approach for the treatment of condy-  lar fractures is favorable for fractures of the condylar base  and the condylar process. The biggest benefit and advantage  in comparison to all extraoral approaches is the very low  complication rate concerning facial nerve injuries and the    neck fracture. (c) Condylar neck fracture after repositioning and fixa-  tion employing an intraoral approach    Table 54.1 Advantages and disadvantages of an intraoral approach for  the treatment of condylar fractures   e Very low risk for salivary fistulas, sialoceles or Frey syndrome  ¢ No risk for disturbance of the great auricular nerve  Disadvantages    avoidance of extraoral scars. A disadvantage is the need for  special equipment to facilitate this technically demanding  procedure with regular success (Table 54.1).   Clinical features: Malocclusion with lateral open bite left.  Limited and painful mouth opening. Mobile mandible  paramedian region left. Chin hematoma.    54 Intraoral Endoscopic Approach for Treatment of Condylar Fractures of the Mandible 1123    fracture right. (c) Postoperative panoramic X-ray showing well-suffi-  cient reduced and with miniplates stabilized fractures paramedian left  and at the condylar process right    Fig.54.17 (a) 3D reconstruction of the preoperative CT scan showing  the medial displaced condylar process fracture right and slightly dis-  placed paramedian fracture left. (b) Coronal view of the preoperative  CT scan showing the medial out of the fossa displaced condylar process    2. Vural E. Treatment of adult subcondylar mandibular fractures:  closed vs open vs endoscopic approach. Arch Otolaryngol Head  Neck Surg. 2004;130(10):1228-30.   3. Hall MB. Condylar fractures: surgical management. J Oral  Maxillofac Surg. 1994;52(11):1189-92.    Surgical plan: Open reduction and internal fixation of both  fractures employing an intraoral approach. The parame-  dian fracture should be fixed first with two miniplates. A    gap of the lingual cortex should be prevented by compres- 4, Bilis E 3rd, Dean J. Rigid fixation of mandibular condyle fractures.  sion of the mandible in the posterior region and overbend- Oral Surg Oral Med Oral Pathol. 1993;76(1):6-15.  ing the plates. The condylar neck fracture should be fixed 5. Haug RH, Assael LA. Outcomes of open versus closed treatment  second with two miniplates as well of mandibular subcondylar fractures. J Oral Maxillofac Surg.  ‘ : _. 2001;59(4):370-S. Discussion 375-6  Postoperative findings: Sufficient reduced and stabilized frac- —_¢, Vogt A, Roser M, Weingart D. Transparotidean approach to surgical  tures at the condylar process right and paramedian left management of condylar neck fractures. A prospective study. Mund  (Fig. 54.17c). Proper occlusion and regular mouth opening Kiefer Gesichtschir. 2005;9(4):246-50 [Article in German].  4 weeks after surgery without any deviation during ds Patil RS, Gudi SS. Management of subcondylar fracture through  ” intraoral approach with rigid internal fixation. J Maxillofac Oral  function. Surg. 2011;10(3):209-15.  8. Schén R, Gutwald R, Schramm A, Gellrich NC, Schmelzeisen  R. Endoscopy-assisted open treatment of condylar fractures of the  mandible: extraoral vs intraoral approach. Int J Oral Maxillofac  Surg. 2002;31(3):237-43.  References 9. Silverman SL. A new operation for displaced fractures at the neck  of the mandibular condyle. Dental Cosmos. 1925;67:876.  1. Rozeboom AVJ, Dubois L, Bos RRM, Spijker R, de Lange J. Open _—_10. Fritzemeier C, Bechthold H. Die Osteosynthese von Unter kiefer-    treatment of condylar fractures via extraoral approaches: A review  of complications. J Craniomaxillofac Surg. 2018;46(8):1232—40.    Mokros S, Erle A. Transoral miniplate osteosynthesis of mandibu-  lar condyle fractures—optimizing the surgical method. Fortschr  Kiefer Gesichtschir. 1996;41:136-8.   Veras RB, Kriwalsky MS, Eckert AW, Schubert J, Maurer P. Long-  term outcomes after treatment of condylar fracture by intraoral  access: a functional and radiologic assessment. J Oral Maxillofac  Surg. 2007;65:1470-6.   Jensen T, Jensen J, Ngrholt SE, Dahl M, Lenk-Hansen L, Svensson  P. Open reduction and rigid internal fixation of mandibular condy-  lar fractures by an intraoral approach: a longterm follow-up study  of 15 patients. J Oral Maxillofac Surg. 2006;64:1771-9.    Schneider M, Lauer G, Eckelt U. Surgical treatment of fractures of  the mandibular condyle: a comparison of long-term results follow-  ing different approaches—functional, axiographical, and radiologi-  cal findings. J Craniomaxillofac Surg. 2007;35:15 1-60.   Schramm A, Wilde F. Computer-assisted reconstruction of the  facial skeleton. HNO. 2011;59(8):800-6.   Wilde F, Schramm A. Intraoperative imaging in orbital and midface  reconstruction. Facial Plast Surg. 2014;30(5):545-53.    Open Access This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.  org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropri-  ate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.   The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in  a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.   Complex midface trauma has challenged the diagnostic and  operative skills of surgeons through the decades. Robert  Marciani in his fifty year review article dated 1993, vividly  described the challenges faced by early surgeons regarding  the clinical and radiological diagnosis of mid face fractures  and the compromised surgical results that may ensue [1].    In an area so anatomically complicated as the midface, the  lines of fracture produced in the middle third are classified  based upon the experimental studies of René Le Fort in 1901  [2]. The earliest known writings of maxillofacial fractures  were recorded in the Edwin Smith papyrus in 1650  BC. Hippocrates who is often portrayed as the “Father of  Medicine” described a myriad of facial injuries around 400  BC and his insight provided the basis for bandages and sin-  gle jaw interdental wiring as methods of fixation and stabili-  zation of facial fractures. Over the subsequent centuries,  there appeared many techniques which in essence were vari-    O. A. Jacob (x)  Department of Oral and Maxillofacial Surgery,  Ananthapuri Hospitals and Research Institute,  Trivandrum, Kerala, India    © The Association of Oral and Maxillofacial Surgeons of India 2021    1822 Charles Fredrick First treatise on maxillary fractures  Reiche  1823 Carl van Graefe    Paper on midfacial fracture patterns  Used a Halo frame which was secured  directly to the skull using pins    ations of what Hippocrates had described. In the nineteenth  century, Charles Fredrick Reiche provided the first detailed  treatise on maxillary fractures [3]. It was also in the same  century that Garretson and Blair advocated mandibular-  maxillary fixation with the aid of splints to primarily treat  maxillary fractures.   In 1901, a French surgeon René Le Fort published his  classic paper on midfacial fracture patterns. He inflicted  blunt facial trauma on cadavers, then subsequently removed  the soft tissue and examined fracture patterns of the facial  skeleton. This study has ever since been the basis for the  description of maxillary fractures.    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1-15-1346-6_55    The middle third of the facial skeleton is made up of the following bones (Fig. 55.1)   3. Two zygomatic processes of the temporal bones  4. Two palatine bones    The middle third of the face is made up of a number of  bones which rarely fractures in isolation. The complex  nature of the midface is such that it will withstand the  forces of mastication from below and provide protection in  certain areas for vital structures. The middle third of the  facial skeleton consists of a series of bone struts (but-  tresses) passing upwards from the upper teeth to the bones  of the skull [4] (Fig. 55.2).    The relative fragility of the midface skeleton makes it act as  a cushion for trauma directed towards the cranium from an  anterior or anterolateral direction. The facial skeleton can be  designated by this famous figure, where the skull is similar to a  helmet, the midface is similar to a matchbox (crumble zone)  and the mandible is similar to a hockey stick (Fig. 55.3). The  most common causes of facial fractures in the adult population  are assaults and motor vehicle accidents [5].    Fig. 55.2 Vertical and horizontal buttresses of the facial skeleton (Also refer Fig. 60.9 and Table 60.2)    The midface is composed of the nasal, zygoma, maxilla, eth-  moid and its conchae, palatine, inferior concha and vomer  which are collectively referred to as the middle third of the  facial skeleton. The facial bones in isolation are compara-  tively fragile but gain strength and support as they articulate  with each other. It is this strength that has often been  described as the facial buttresses which Manson alluded to  when describing the vertical and horizontal struts that sup-  port the facial skeleton [6]. The horizontal pillars are formed  by the frontal bar (composed of the supraorbital rims and  nasal process of the frontal bone), the zygomatic arch, the  infraorbital rims and the nasal bridge and finally the alveolar  process of the maxilla. The vertical pillars are the medial pil-  lar formed by the piriform rims which continues superiorly  as the frontal process of the maxilla. The zygomatic but-  tresses which continue superiorly with the lateral orbital    rims form the lateral pillars, and the most caudal pillars are  the pterygoid plates.   The maxilla consists of a central body and four processes,  namely, the frontal, zygomatic, alveolar and palatine pro-  cess. The body is hollowed out and contains the maxillary  sinus. It is pyramidal shaped with the base being the medial  surface facing the nasal cavity and the apex being elongated  into the zygomatic process. It has an orbital or superior sur-  face which forms the floor and rim of the orbit, a malar or  anterolateral surface which forms part of the cheek and a  posterolateral or infratemporal surface which contributes to  the infratemporal fossa. The base is rimmed inferiorly by the  alveolar process. The alveolar process houses the dental arch  with the sockets varying in size according to the teeth. The  palatine process is a horizontal process from the body to the  alveolar process and medially articulates with the palatine  process of the opposite maxilla, while posteriorly it articu-    Fig. 55.3 Helmet, matchbox  and hockey stick to illustrate  relative bone strength (the  matchbox is the crumble zone)    lates with the horizontal plate of the palatine bone. The zygo-  matic process is an extension of the anterolateral surface of  the body which contributes to the zygomaticomaxillary  suture. The frontal process projects upwards to articulate  with the maxillary process of the frontal bone as well as the  nasal bone anteriorly and the lacrimal bone posteriorly.   The blood supply to the maxilla and the palatine bones is  through the periosteum, the incisive artery and the greater  and lesser palatine arteries. The internal maxillary artery lies  posterior to the maxillae and the palatine bones and anterior  to the pterygoid plates of sphenoid.   The maxillary nerve enters the caudal maxilla ventral to  the orbit via the maxillary foramen and runs through the  maxilla in the infraorbital canal giving off branches to supply  the maxillary cheek and teeth. The nerve then exits the max-  illa at the infraorbital foramen.    Maxillary fractures were classified by René Le Fort based on  his experiments on cadavers with low velocity unidirectional  frontal trauma. Although the present-day maxillary fractures  are caused due to high velocity multi directional trauma, the    Le Fort classification is still widely followed due to its sim-  plicity and the levels of anatomic differentiation it offers.  Other authors have attempted classifications based on the  anatomical sites and based on the involvement of the occlu-  sion. Marciani modified the basic Le Fort classification by  adding frontal bone and zygomatic fractures.   The fracture line extends backwards from the lateral margin of the  anterior nasal aperture below the zygomatic buttress to cross the  lower third of the pterygoid laminae. The fracture also passes  along the lateral wall of the nose and the lower third of the septum  to join the lateral fracture behind the tuberosity (Fig. 55.4a-c).   This fracture runs from the thin middle area of the nasal  bones down either side, crossing the frontal processes of  maxillae into the medial wall of each orbit; the fracture line  crosses the lacrimal bone behind the lacrimal sac before  turning forwards to cross the infraorbital margins slightly  medial to or through the infraorbital foramen. The fracture  now extends downwards and backwards across the lateral  wall of the antrum below the zygomaticomaxillary suture  and divides the pterygoid laminae about half way up.    Fig. 55.4 (a, b) Le Fort I fracture lines. (ec) CT of Le Fort I fracture    Separation of the block from the base of the skull is com-  pleted via the nasal septum and may involve the floor of the  anterior cranial fossa (Fig. 55.5a—d).   The fracture runs from near the frontonasal suture trans-  versely backwards and parallel with the base of the skull and  involves the full depth of the ethmoid bone including the  cribriform plate. Within the orbit the fracture passes below  the optic foramen into the posterior limit of the inferior  orbital fissure. From the base of the inferior orbital fissure,    the fracture line extends in two directions: backwards across  the pterygomaxillary fissure to fracture the roots of the ptery-  goid laminae and laterally across the lateral wall of the orbit  separating the zygomatic bone from the frontal bone. In this  way the entire middle third of the facial skeleton gets sepa-  rated from the cranial base (Fig. 55.6a-c).    Le Fort classification does not take into consideration:  ¢ Dentoalveolar fractures  e Palatal fractures  ¢ Bone loss    Fig. 55.5 (a, b) Le Fort II fracture lines. (¢) CT of Le Fort II fracture showing the midface segment impacted (red arrows). (d) Clinical image of  case in ¢, showing the impacted area right side Le Fort II (yellow arrow)    Fig. 55.6 (a, b) Le Fort II fracture. (c) CT of Le Fort III fracture (the fracture lines shown with red arrows)    55.2.2 Killey’s Classification (1965) [2] Addenda  (Table 55.2) (i) These fractures may occur unilaterally or be associated  independently with a fracture of the zygomatic  ; oe complex.  epee es ietley Scleneson (ii) There may be a midline separation of the maxillae and/  1. Dentoalveolar fractures or extension of the fracture pattern into the frontal or   55.2.3 Rowe and Williams's Classification Fractures involving the cranial base and other midface frac-  (1985) [2] (Table 55.3) ture configurations, including severely comminuted seg-    Fractures of type A and type B  which extend into ethmoid  bone (naso ethmoid) (C)    Fractures NOT  involving Fractures of type A, B, C which  the occlusion extend into the frontal bone.  (fronto orbito  nasal dislocation)    Fractures involving the zygomatic  bone, arch and maxilla (zygomatic  Classification based complex) excluding the    Le Fort  II—Pyramidal  55.2.5 Palatal Fractures Classification: fractures  Hendrickson’s Classification (1998) [7]  (Figs. 55.7, 55.8, and 55.9; Table 55.5) Heo ee   IV a—supraorbital rim fracture  IV b—anterior cranial fossa  and supraorbital rim fracture  IV c—anterior cranial fossa  and orbital wall fracture    Fig. 55.7 Hendrickson’s classification of palatal fractures. (a) Type Ia, (b) Type Ib, (c) Type IL, (d) Type III ,(e) Type IV, (f) Type V, (g) Type VI    Fig. 55.8 (a) CT of Hendrickson’s type C fracture. (b) Clinical image of case of a, showing the midline diastema    Fig. 55.9 CT of midline palatal fracture with splayed segments, note  the posterior displaced fragment, temporary bridle wire has been placed  between upper central incisors    Gross facial swelling or facial disfigurement is generally  not a feature of Le Fort I fractures, but oedema around the  upper lip may occur. Soft tissue injury along the upper lip  along with tearing of gingivae may occur due to the caus-  ative impact. There can be mobility of the upper dento-  alveolus when digital pressure is applied. Mobility of the  maxilla at the Le Fort I level must be differentiated from  extended maxillary dentoalveolar fracture. Malocclusion    may occur if the fracture is displaced or impacted. Dorsal  and caudal pull of the medial pterygoid muscles can con-  tribute to the posterior displacement of the maxilla and the  resultant anterior open bite (Fig. 55.10a, b). Bilateral epi-  staxis is rare although emphysema may occur if the patient  blows his nose. Ecchymosis in the upper buccal sulcus is a  frequent finding. Percussion of the maxillary teeth pro-  duces a dull cracked cup sound. In case of inferiorly dis-  placed Le Fort I fractures, the patient may have to keep the  mouth open to accommodate the increased vertical dimen-  sion. Due to the extreme downward displacement of the  maxilla, the nasal base is lost, leading to stretching of the  soft tissues of that area, which makes it possible to see  directly into the nares.   The posteriorly impacted Le Fort I fracture may result in  an anterior open bite and in these cases the maxilla may be  immobile. Usually the impacted maxilla can be mobilized by  grasping the maxillary teeth and applying a firm anterior  pull. A grate may be felt due to the movement between the  fractured segments. In posteriorly impacted fractures, there  may be damage to the cusps of maxillary teeth usually in the  premolar region, caused by the upward impact of the man-  dibular teeth at the time of the trauma. The complete Le Fort  I fracture may be associated with a split along the median  palatal suture. Sometimes more than one fracture line may  be present in the palate, so that either one or both fragments  may be mobile (Fig. 55.1 1a—c).    Marked facial disfigurement resulting from circumorbital  ecchymosis and gross oedema can be a feature of Le Fort  II fractures. Frequently the patient will not be able to open    Type la: anterior alveolus, contains only  incisor teeth and associated  alveolus    palatal midline; typically occurs in  second or third decade because of a  lack of ossification of the midline  palatal suture.    Type Ill: parasagittal fracture; most  common fracture pattern in adults,  pattern differs from type la by inclusion  of maxillary canine.    Type IV: para alveolar fracture, occurs  palatal to the maxillary alveolus and  incisors    Type VI: transverse fracture, rare,  involves a division in the coronal  plane.    Clinical features Le Fort I Le Fort II Le Fort II  Intraoral ¢ Floating maxilla ¢ Deranged occlusion ¢ Deranged occlusion  ¢ Impacted or telescopic fracture ¢ Posterior gagging of occlusion —* Posterior gagging of occlusion  ¢ Anterior open bite ¢ Possible airway obstruction ¢ Possible airway obstruction  ¢ Deranged occlusion  ¢ Guerin’s sign  ¢ Palatal fracture in some cases  Extraoral ¢ Mild swelling and oedema of midface * Moon face appearance ¢ Separation at FZ suture    Fig. 55.10 (a, b) A posteriorly telescoped Le Fort I fracture maxilla clinically manifesting as anterior open bite    Fig. 55.11 CT images (a, b) showing a right zygomatic complex fracture associated with a Hendrickson’s type B fracture where the right poste-  rior alveolar and palatal segment was displaced palatally and extruded, causing the occlusal discrepancy (crossbite) as seen in ¢    his eyelids to allow an ocular examination. Subconjunctival  haemorrhage may be present, the posterior limit of which  cannot be identified. Bilateral peri-orbital oedema and cir-  cumorbital ecchymosis (described as circumorbital as it  follows the shape of the orbicularis oculi muscle) are  described as racoon eyes or panda facies. There can be  severe oedema of the face which is sometimes described  as moon facies. Enophthalmos in case of orbital floor  fractures may go undetected due to oedema. Considerable  lengthening of face with posterior gagging of teeth can  also occur. Bilateral epistaxis is common, and CSF leak  may be present. The loss of maxillary prominence may  result in a dish face appearance. If the fracture line passes  through the infraorbital canal there can be associated par-  esthesia in the infraorbital nerve region. While clinically  mobilizing the maxilla in a Le Fort IJ fracture, transmitted  mobility may be felt at the infraorbital rim and the fronto-  nasal suture. Figure 55.12 shows a CT image where Le  Fort II and II] lines are seen    This fracture is clinically similar to the Le Fort II fracture but  can demonstrate a more serious condition. Bilateral ecchy-    Fig. 55.12 CT image showing Le Fort I and II fractures. Note that  maxilla is rotated to the right side with canting on the left side.    mosis with circumorbital oedema may close the eyes com-  pletely. As in Le Fort II, the posterior limit of the  subconjunctival haemorrhage cannot be seen. The lengthen-  ing of the face occurs due to the loss of bony fixation to the  base of the skull. The flattening of the face from the dis-  rupted zygomatic bones is usually masked by the gross  oedema. The fracture passes above the Whitnall’s tubercle  and so the support by Lockwoods, suspensory ligament is  lost. This results in hooding of upper eyelid which becomes  obvious when the oedema subsides. Gagging of occlusion  and shift of the maxillary midline may occur. Gross posterior  displacement of the maxilla can result in the soft palate  touching the posterior part of the tongue causing airway and  speech impairment. As with other maxillary fractures, per-  cussion of teeth might produce a cracked cup sound. .   The clinical differentiation between Le Fort II and Le Fort  III fractures can be assessed by palpating for step deformity  in the infraorbital rim in the former.    The Le Fort fractures may manifest without the classic frac-  ture patterns as described above. An unilateral fracture at Le  Fort I level may occur (identified through imaging) which  warrants no intervention unless accompanied by a palatal  fracture causing occlusal derangement and/or mobility. Such  a unilateral fracture pattern can cause unilateral gagging  causing open bite on the contralateral side   The clinician must be aware of the two types of Le Fort I  fractures, the mobile and impacted variants; lack of mobility  should not be presumed as absence of fracture.    It is difficult to diagnose fractures of the middle third of the  face with plain films and CT scans have now largely replaced  radiographs.   The commonly used radiographs for identifying maxil-  lary fractures are occipitomental view (OMV) 10° and 30°  and paranasal sinus view 37° (PNS -Waters view).   While assessing maxillary fractures with these radio-  graphs, Mcgregor-Campbell and Trapnell’s lines and Dolan’s  lines (elephant of Rogers) may be kept in mind [8].   These lines were described by McGregor and Campbell  for ease of searching on an occipitomental view 10-degree  frontal projection.    1. First line across the zygomaticofrontal, the superior mar-  gin of the orbit and the frontal sinus   2. Second line across the zygomatic arch, zygomatic body,  inferior orbital margin and nasal bone    3. Third line across the condyles, coronoid process and the  maxillary sinus / Zygomatic buttress region   5. Fifth line (Trapnell’s line, added later) across the inferior  border of the mandible from angle to angle (Fig. 55.13)  The four S’s described by Delbalso, Hall and    Dolan’s lines are the collective name given to three lines  described by Dolan and Jacoby that aid in evaluating for max-  illofacial fractures on an occipitomental skull radiograph.  They are usually used as an adjunct to McGregor-Campbell  lines.    ¢ Orbital line (line 1) traces the inner margins of the  lateral, inferior and medial orbital walls and the nasal  arch.    ¢ Zygomatic line (line 2) traces the superior margin of the  zygomatic arch and body extending along the frontal pro-  cess of the zygoma to the zygomaticofrontal suture.   ¢ Maxillary line (line 3) traces the inferior margin of the  zygomatic arch, body, and buttress and the lateral wall of  the maxillary sinus.    Lee Rogers pointed out that the second and third lines of  Dolan give the outline of the head of an elephant.    CT scans are now the gold standard for a definitive diagnosis in  fractures of the maxilla. A CT scan in all three planes (axial,  sagittal and coronal) along with a 3D reconstruction will aid the  surgeon in accurate assessment of fracture patterns and also will  aid in preoperative planning. The surgeon must never rely on the  3D CT alone but should correlate the images with those obtained  in axial sagittal and coronal planes, as there could be  reconstruction-related errors which appear as fracture lines or  bone defects. CT scan-based fracture patterns may be classified  as low, middle or high energy, defined solely by the pattern of  segmentation and displacement in the CT scan [9].    The primary aim of treatment of maxillary fractures is to re-  establish the dental occlusion and masticatory efficiency.  The contribution of the maxilla to the projection and contour  of the midface has also to be considered in the management  of maxillary fractures and requires a clear understanding of  the facial buttress system, subunit anatomy and _inter-  relationships of the various bones [10]. This aesthetic aspect  is often compromised by associated injuries of the zygomatic  complex, nose and orbits.    The basic principles of the treatment of maxillary frac-  tures are:   2. Reconstitution of the bony buttresses of the mid-  face so as to prevent elongation of the face and/or  antero-posterior collapse of the maxilla   4. Replacement of missing/grossly comminuted bone  at the buttresses with autogenous bone grafts [5]   4. Anatomic repositioning and stable fixation of frac-  ture segments in all planes of space [11]    Proper reduction of maxillary fractures is the key to achiev-  ing good dental occlusion and needs proper clinical exami-  nation of the fracture pattern after all the accessible fracture  sites are exposed. A repeat study of the CT scans (axial,  coronal and 3D) and correlation with the exposed maxilla  will aid the surgeon in planning adequate reduction and  rigid fixation. It should be kept in mind that the fractured  maxilla is usually displaced backwards and downwards and  hence the reduction should in the forward and upward direc-  tion. To obtain reproducibly good results, even with the  most extensive facial dislocations, the surgeon should  restore the facial architecture at the Le Fort I Level [12]. In    rare occasions, lateral en bloc displacement of the maxilla is  seen, and this requires transverse reduction to achieve the  correct dental occlusion. A depressed zygomatic fracture  can physically prevent reduction of the maxilla. Hence the  fractured zygomatic bone should be reduced prior to manip-  ulating the maxilla.   The most useful instruments for reduction of the maxilla  are the Rowe’s disimpaction forceps. Even in cases where  the fractured maxilla appears to be minimally displaced, it is  prudent to mobilize the bone with the disimpaction forceps  so as to overcome any bony interferences and thus freeing  the maxilla completely. When using this paired forceps, care  should be taken to avoid injury to the anterior teeth and also  to the palatal mucosa. Mobile, extruded and proclined ante-  rior teeth are at particular risk, and an assistant should closely  observe the anterior teeth, while the surgeon is manipulating  the fractured maxilla. It would also be advisable to obtain  informed consent regarding mobility or loss of these teeth.  Trauma to the nasal floor is inevitable when mobilizing the  maxilla using the reducing forceps, and some nasal bleeding  is usually observed, but this rarely requires a nasal pack.   2. Alignment of the paranasal, zygomatic and fronto-  zygomatic bony buttresses    Problems arise when the patient has few or no teeth and  when there is gross comminution of maxilla. In these situa-  tions the surgeon has to make do with whatever landmarks  are available, and in such cases compromised functional and  cosmetic results are not uncommon.   Direct manipulation at the fracture lines is sometimes  required especially when the fractured maxilla is telescoped  into the superior normal bone. Care must be taken to prevent  additional fractures at the bony margins during direct manipu-  lation as this would make fixation more demanding. Using tie  wires at the zygomatic buttresses, around the second maxillary  premolars/first molars bilaterally and through anterior nasal  spine is often useful to physically disimpact and pull the max-  illa forwards and upwards thus ensuring good reduction.   When the maxilla is fractured in multiple levels (e.g. Le  Fort I and III levels), reduction using the disimpaction for-  ceps alone may not be adequate. The dental occlusion can be  achieved, but the midface projection may be compromised.  Here also a combination of reduction with disimpaction for-  ceps, direct manipulation at the fracture site and the use of  the above mentioned tie wires is often indicated.    Once adequate reduction of the fractured maxilla is  obtained, it is mandatory that rigid maxillomandibular fixa-  tion (MMF) is applied. In almost all cases, well-adapted max-  illary and mandibular arch bars are required as this ensures  multiple points for the MMF. Failure to obtain rigid MMF or  manually maintaining the dental occlusion during fixation  can result in post-operative occlusal discrepancies. If surgical  reduction and fixation of the maxilla has to be delayed, elastic  traction will be helpful in obtaining a functional occlusion.  The use of MMF screws definitely saves operating time but  can be problematic if elastic traction is required later.   If the mandibular condylar fracture exists, this should be  reduced and fixed prior to the MMF. Failure to do so may  result in an open bite due to loss of posterior mandibular  height.    Internal wire suspension involves sandwiching the fractured  portion of the maxilla between the mandible and the superior  part of the facial skeleton/skull that is not fractured. The use  of internal suspension wires is more or less obsolete unless  there is severe comminution which precludes rigid internal  fixation. Suspension wiring may also be the surgeon’s choice    when there is presence of severe infection at the site of sur-  gery (Fig. 55.15).    Although many wiring techniques were practised in the past,  rigid internal fixation with titanium bone plates and screws  of sufficient rigidity is now the standard of care. For internal  fixation of the maxilla, titanium bone plates and screws of  sufficient rigidity are used. For providing rigidity, screws  with an outer diameter of 1.5 mm is commonly used.    When treating a very high Le Fort I fracture and in Le Fort II  and III fractures, it may be necessary to use one or more of  the following incisions, which are described in chapter 56  and 57 of this book:    1. Skin incisions for exposure of the infraorbital rim.  Extension of this incision medially ensures access to the  lateral nasal area, while a lateral extension would give  access to the upper portion of the zygomatic body.   2. Upper eyelid or lateral eyebrow incision (blepharoplasty)  to expose the fronto-zygomatic suture.   The maxilla can be approached through a variety of inci-  sions, the most common being the maxillary vestibular  approach. In addition to providing access to the lower part  of the entire midfacial skeleton, this approach results in a  hidden intraoral scar. This approach may result in disrup-  tion of the attachments of the facial muscles of the nasola-  bial region; hence careful repositioning during closure is  recommended to avoid unaesthetic changes to the face. The  muscles of importance are the nasalis group, the levator  labii superioris alaeque nasi, the levator labii superioris, the  levator anguli oris and the orbicularis oris. The vestibular  incision and subsequent dissection causes stripping of ori-  gin/insertion of most muscles originating in the maxilla.  These muscles tend to get reattached in a shortened manner  due to the action of the zygomaticus muscle. Deepening of  the alar groove and splaying of the alar bases, nostrils and  nasal tip may occur following lateral displacement of the  nasal modiolus. Soft tissue fullness loss in the naso-alveo-  lar region may result in thinning and retraction of upper lip,  reduced vermillion exposure and a obtuse nasolabial angle.  Detachment of the levators of the upper lip may cause down  turning of the corner of the mouth (Fig. 55.16).    e Sharp elevation of the superior flap will ensure a  subperiosteal plane of dissection, but this may not  always be possible due to adherent tissue at the  fracture sites and the presence of bony fragments in  comminuted fractures. As far as possible, sizable  fragments of loose bone with soft tissue attach-  ments should be retained to avoid large gaps at the  fracture site which might delay healing. Even com-  pletely denuded bone can be replaced as free autog-  enous grafts and fixed in place with tissue glue or  fine stainless steel wires.   e As the superior dissection proceeds, care should be  taken to identify and protect the infraorbital nerve  which may be involved in the fracture. It is also pru-  dent to palpate the infraorbital margin to ensure that   Yellow arrows denoted the Le Fort I fracture lines when comminution of the infraorbital rim and floor  is present.   e Once the flap has been adequately raised, long  Langenbeck retractors placed superiorly and cheek    Clinical Tips for approaching the Le Fort fracture via retractors at the corners of the mouth will ensure good   maxillary vestibular incision surgical exposure and adequate lighting and thus aid in  reduction and fixation of the fracture (Fig. 55.17).    the lips and corners of the mouth especially in  patients with a small oral aperture.   It is important to place a high vestibular incision to  ensure a wide gingival cuff of tissue which will aid  in closure of the incision.   “Counter” elevation of the gingival cuff would aid in  closure and also expose the root prominences, and  this would be helpful during adaptation of the mini-  plates and the subsequent screw fixation.   It is also recommended that the opening of the  Stenson’s duct be identified so that injury to this  structure is avoided when the buccal sulcus is  stretched while making the incision.   Some surgeons mark the midline to ensure proper  reapproximation of the tissues during closure. This  is important in cases where one is forced to use an  oral endotracheal tube exiting from one corner of the  mouth which may distort the oral tissues.   Extension of the posterior end of the incision  beyond the first molars may cause buccal fat hernia-  tion into the surgical site. This is of minimal con-  cern but can be annoying to the surgeon during  plate fixation.    rate vestibular incisions bilaterally without incising  the midline frenal attachment. This variation will  not disturb the mid line lip anatomy in cases where  exposure of the anterior nasal spine region is not  required.    Fig. 55.17 A clinical situation where the separate vestibular  maxillary incisions were given to approach anterior maxilla, due  to deep through and through lip laceration upper lip extending  down to the frenum region    Early intervention (7-10 days) with open reduction  and fixation is the treatment of choice for maxillary Le  Fort I fractures. Restoration of normal facial contour and  occlusion is considered as optimal outcome of treatment.  Bone reconstruction should be completed as early as pos-  sible to minimize shrinkage, stiffness and scarring of soft  tissues [12].   In complex panfacial fracture management, many  authors have stressed the importance of managing the  Le-Fort fracture while reconstituting the facial architec-  ture [13, 14].    Adequate fixation of the fractured bone depends on two fac-  tors, namely, the rigidity of the plate and the friction between  the bone fragments (buttressing of the bony segments).  When a gap exists between the bone ends, the latter factor is  missing. In these cases, non/fibrous union can result if the  masticatory forces are greater than the rigidity of the plate.  As a general principle, the paranasal and zygomatic but-  tresses must be rigidly fixed. The plates should be well  adapted especially where the bone stock is poor. At least two  screws must be present on either side of the fracture and  more the number of screws, better the, load sharing, between  the plate and the subjacent bone. Opposed to this is when  there is no bone buttressing and the plate has to be ‘load  bearing’. Also a minimum of two threads of the screw  should engage the cortical bone. This may be a problem in  thin areas as the anterior wall of the maxillary sinus and the  alveolus where roots are present. In the edentulous maxilla,  the bone quality is often compromised, and the lower end of  the plate may need to be placed on the alveolus. This may  necessitate removal of the plate prior to prosthodontic  rehabilitation.   Obtaining rigid fixation becomes difficult when the but-  tresses are comminuted. If only one buttress is amenable for  plating the reduction at this fracture interface along with  reconstitution of the occlusion must be used as the template  for repositioning the maxilla. When all the buttresses are  comminuted, the surgeon has to “eye ball” the maxilla into  the reduced position. In these situations, a long-span plate  extending from the body of the zygomatic bone to the rela-  tively thick bone in the area of the anterior nasal spine with  or without a bone graft is often the only option available to  maintain the vertical position of the floating maxilla. It has  been stated that the lip-tooth relationship is helpful in decid-  ing the position of the reduced maxilla, but in practice this is  of limited use.   Loss of bone at the buttresses may require the use of pri-  mary bone grafts [10]. Though it has been suggested that a   . Loss of a large part of the anterior wall of the max-  illary sinus (Fig. 55.18) (causing the overlying soft  tissue to fall into the sinus causing a contour defect)    gap of more than 5 mm at the buttresses requires a graft, rigid  plate fixation followed by MMF is often enough to ensure  bony healing.   Primary bone grafting can be done using iliac bone  (Fig. 55.26), split calvarium or split ribs. The calvarium is  the preferred source because of the following reasons:    1. Large amount of graft available  2. Proximity to the operative field  3. Minimal donor site morbidity    The disadvantage is that these grafts are brittle and cannot  be contoured. The bone graft has to be mortised to fit the  defect and must be fixed rigidly to the plate or lag screwed.    Fig. 55.18 A clinical situation where the defect in the anterior wall  maxilla due to comminution of the wall was partly covered by fixing the  free segment (red arrow). The long-span plate from the buttress to the  anterior maxilla region can also be seen    Incisions for open reduction can be placed from first  molar to first molar regions through a vestibular approach for    Fig. 55.19 The surgeon stands behind the patient and applies the dis-  impaction force, while the head is stabilized by the assistant surgeon    wide exposure of the fracture sites. Rowe’s disimpaction for-  ceps and/or Hayton-Williams forceps can be used for mobi-  lizing and reducing the fracture into position. The impacted  type of Le Fort I fracture manipulation has to be done by  grasping the maxilla with two pairs of Rowe’s disimpaction  forceps. Osteotomizing the maxilla should be considered if  there is significant interval between the time of trauma and  surgery. Whenever possible a passive reduction of the max-  illa with condyles firmly seated in their correct position  should be ensured to avoid post-operative anterior open bite  (Figs. 55.19, 55.20, and 55.21).    Use of Rowe’s Rowe’s disimpaction forceps are available as  disimpaction paired (right and left) instruments  forceps Each instrument has two blades, one for    engaging the palate (to be padded before use to  avoid injury to the palatal mucosa) and one to be  inserted through the nostril   The instrument has an outward bend at the  handle which aids in the use of two forceps  simultaneously   After engaging the forceps, the maxilla has to be  moved in all planes to ensure adequate  mobilisation    The Hayton-Williams forceps is used to hold  the fractured maxilla together   The instrument is inserted after vestibular  incision and is engaged at the pterygoid region  This is the instrument of choice especially in  cases with palatal bone fracture    After reduction the maxilla should be placed into maxillo-  mandibular fixation. The fixation of the fracture sites (four-  point fixation) is done at the vertical pillars of nasomaxillary  and zygomaticomaxillary (lateral piriform rim and zygo-  matic buttress regions) for which the preferred plates and  screws used are 1.5-mm thickness with 6-mm long screws.  In the zygomatic buttress regions, 2.0-mm profile plates also  can be used. The mini-plates are fixed as close as possible to  the lateral pyriform rim as the bone is thickest there. Usually  stabilization of the fracture is achievable even if any three of  the four buttresses are fixed. Apparently, gross communition  at one of the buttress regions will not cause a significant risk  of inadequate stabilization. The associated anterior wall of  the maxillary sinuses is generally not fixed due to the relative  thin nature of bone in this region. The larger free bone frag-  ments can be repositioned and immobilized using wires or be  used for reconstruction of orbital floor defects. The circum-  vestibular incision is closed with running resorbable sutures  after ensuring that the midline of upper lip coincides with the  facial midline (Fig. 55.22).   Maxillomandibular fixation of up to 6 weeks also can be  considered as alternative for treatment though the results  may be less satisfactory with added morbidity to the recover-  ing patient. The readers are advised to refer chapter 50 to  read about closed reduction / wiring and intermaxillary fixa-  tion techniques.    The pyramidal fracture has the apex of the fracture located at  the nasofrontal suture region or at the midnasal bone level.  The Le Fort II fractures are ideally fixed at the frontonasal  suture region, bilateral infraorbital rims and also both zygo-  maticomaxillary buttresses. However in majority of the clini-  cal situations fixation at the infra orbital rims and the  zygomatic buttress regions gives reasonably good results.  Most Nasal bone fractures associated with Le Fort II fractures  can be adequately managed by closed reduction techniques.  This may require the anaesthetist to change nasal intubation  to oral intubation. A submental intubation may also be con-  sidered at the beginning of the procedure. If the nasofrontal  segment is unstable, fixation of the area can be done through  various approaches (existing laceration, Gull wing approach,  etc.). A maxillary vestibular incision can frequently provide  access to infraorbital fracture alignment and fixation in some  cases. The lower eyelid approaches are not always mandatory    Fig. 55.22 The zygomatic buttress and paranasal buttress fixed in a  classical Le Fort I fracture maxilla    Fig. 55.23 Le Fort II fracture lines at the infraorbital rim area may  have to be accessed directly, if required, especially with associated  zygomatic/orbit fractures. In this case the lateral orbital rim reconstruc-  tion is done via combined access from left sub ciliary incision and left  supra tarsal incision    for fixation unless simultaneous exploration and reconstruc-  tion of orbital floors are also planned.   In Le Fort II fractures that are complicated by an associ-  ated palatal fracture, surgical splints may be helpful in  obtaining adequate reduction. Placement of maxilla man-  dibular fixation will ensure accurate alignment of midface  structures (Fig. 55.23).    These are complex fractures which rarely occur in isolation  and results in a dysjunction of the facial skeleton from the  base of the cranium. The ideal repair time should be within  10-14 days following the injury but may get delayed due to  neurosurgical issues and other comorbidities.    Incision design for Le Fort III fractures should facilitate  adequate access for reduction as well as fixation of the naso-  frontal, frontozygomatc and in some cases the zygomatic  arches. Using existing lacerations for access avoids need of a  coronal incision, as this allows for complete visualization,  reduction and fixation of the frontal area and zygomatic  arches. A lateral brow or upper blepharoplasty (supra-tarsal  fold) incision may be used to approach the lateral orbital  rims. Also in such cases, a thicker plate (2.0) placement at  the lateral orbital rim may be beneficial. A coronal approach  may have to be considered if bilateral fronto-zygomatic and  nasofrontal fracture fixation is planned.   The occlusion is a reliable indicator of adequate reduction  in cases where direct visualization of the fractured segment  is not possible.   In Le Fort III fractures associated with other fractures  (open facial/condyle fractures), various surgical sequences  can be followed, which is discussed in chapter 60 on  Panfacial fractures.   Rarely, Le Fort fractures may present without mobility,  but show occlusal disturbances like crossbite, open bite or  loss of intercuspation. These can be managed by using trac-  tion elastics but at times warrant mobilization and subse-  quent rigid fixation [15].    Unlike many other areas of the midface, the palatal bone is  relatively thick, and hence palatal fractures are not common. A  palatal split makes reduction and fixation of maxillary frac-  tures more difficult mainly due to the transverse instability  which can cause medial collapse or outward splaying of the  maxilla. The use of the Hayton-Williams forceps along with  the disimpaction forceps will control outward splaying of the  maxilla but at the risk of medially displacement of the dentate  segment of the maxilla. Moreover, the use of all the three for-  ceps effectively requires some amount of surgical expertise.   Moss et al. [16] have proposed a classification for palatal  fractures. There is no consensus regarding the management  of palatal fractures, but various options have been  suggested.   . Direct exposure of the fracture through an existing  palatal laceration or an incision and rigid plate  fixation.   3. External fixation by fixing a screw on either side of  the fracture and immobilization with a wire con-  necting the screws. Alternatively a palatal splint  can be fabricated after sectioning a plaster model of  the palate.    Transpalatal wires are simple to apply and do not have the  problems of soft tissue dehiscence and infection seen in the  more invasive methods [17]. However, the reduction of the  palatal fracture cannot be ensured, and the wires can be cum-  bersome to the patient as it affects speech and swallowing. If  the palatal wires are passed through an infant feeding tube or  a small gauge urinary catheter, injury to the dorsum of the  tongue can be minimized. It is also noticed that palatal wires  tend to become slack after a few days, and then their value in  reduction and fixation of the fracture is questionable.  Moreover, these wires are not an option in the edentulous  maxilla.   Direct exposure and plate fixation are surgically demand-  ing, but the fracture can be reduced and fixed under direct  vision. Ceinfuegos et al. have described the technique of fix-  ing the plate over the palatal mucosa, but this plate would  have to be removed at a later date [18]. An alternative would  be to use a resorbable plate and screws.   Ma et al. has documented the use of self-drilling screws  on either side of the palatal fracture with wires to fix the  fracture [19].    Fig. 55.25 Oronasal fistula in a patient who had sustained palate  fracture    Palatal fractures of the sagittal or parasagittal variety can  be stabilized by placing a mini-plate across the fracture line  on the labial side. Occasionally the prominence of the ante-  rior nasal spine has to be reduced to facilitate mini-plate  placement.   The transpalatal reduction should be supplemented by fixa-  tion at the zygomaticomaxillary and nasomaxillary buttresses  and the use of an arch bar [20].   Palatal fractures accompanied by soft tissue lacerations  often cause a serious challenge to the surgeon regarding its  management. The healing of the palatal soft tissue laceration  is dependent on the exact reduction of the palatal vault and  stabilization. Overzealous attempts at closure of the lacera-  tion without accurate reduction may compromise wound  healing. A tension-free closure of the palatal mucosa is  imperative for wound healing. In some cases, the ensuing  oronasal communication will have to addressed secondarily  (Fig. 55.25).    Concomitant fractures of the palate present additional chal-  lenges to the treatment of Le Fort fractures. They complicate  the re-establishment of proper width and height of the max-  illa. Depending on the fracture type, patient comorbidities  and associated injuries, either closed reduction and wiring or  rigid fixation may have to be performed. Dental impressions  can be obtained and occlusion assessed prior to surgery.    Fabrication of an acrylic splint may help in re-establishing  the transverse width of the palate.   In cases of gross comminution with partial dentition, pal-  atal splints are helpful. Splints are fabricated on casts on  which model surgery has been performed. They are designed  such that they cover the occlusal surfaces and heights of con-  tour, and care should be taken as to not disturb the soft tis-  sues. Holes placed in the occlusal surfaces in the splint aid in  separately ligating it to the arch bar [21]. In case of edentu-  lous patients, Gunning splints are usually used.    Advanced age and compromised medical fitness may  increase the morbidity associated with surgical management  of maxillary fractures. Loss of teeth leading to reduced alve-  olar bone, reduced vascularity of maxilla and greater pneu-  matisation of the maxillary sinuses, should be taken into  consideration before attempting an open reduction and inter-  nal fixation. Modification of existing dentures or Gunning  splints are viable options in this population.    The long-term effects of maxillary fractures on skeletal  growth are inconclusive at present. Mobile-displaced max-  illary fractures in paediatric patients warrant open reduc-  tion and fixation. Removal of hardware in growing patients  may be considered to overcome complications of plate  translocation (shifting of the position of metal plate due to  appositional bone growth), extrusion and possible growth  restriction. Resorbable plating systems may offer a solution  to overcome such complications.    Branches of the internal maxillary artery provide much of  the vascular supply to the midface. In patients with epistaxis    or bleeding, ligation of this artery may be necessary. Due to  anastomoses from other branches of the internal and external  carotid circulation, vascular insufficiency of the maxilla is  unlikely even after ligature of maxillary artery. In certain  conditions of intractable bleeding not amenable to control by  normal packing methods, embolization methods have been  used effectively.    The use of pre-surgical stereolithographic models helps in  plate contouring and precise positioning of fractured seg-  ments. Facilitation of the intraoperative three-dimensional  bone positioning is possible due to development of sophisti-  cated computed tomography, computer graphics hardware  and image processing software capable of reproducing ana-  tomic templates. Automated preoperative “mirroring” of the  contralateral uninjured orbito-zygomaticomaxillary complex  to the affected side can result in improved results. The use of  intraoperative surgical navigation systems along with mobile  cone beam CT improves intraoperative quality control.  Endoscopic midface fracture management facilitates smaller  incisions, reduced recovery time and minimal post-operative  complications. These developments are discussed in the  Chap. 41.    Maxillary fractures can sometimes occur with significant  cosmetic and functional implications. Accurate diagnosis  and early surgical intervention is essential for successful  management of these fractures. The surgeon should keep in  mind that the surgical management of maxillary fractures  primarily aims at restoration of the vertical and horizontal  support buttresses.    55.11 Case Scenario - A case of maxillary  Lefort I fracture where bone grafting  was done (Fig. 55.26a—g)    Fig. 55.26 Case scenario (fracture maxilla fixation done with grafting  in the anterior maxillary sinus wall). (a) 43-year-old man sustained  bone deep laceration on face causing Le Fort I like fracture pattern. In  the emergency department, oral intubation was required due to heavy  bleeding. Nasal packs were placed, and the wound was primarily tacked  as adjunct measures. (b) MIP view of CT scan showing the maxillary  segment displaced downwards will loss of anterior maxillary wall  height. (c) Intraoperative view showing the severely displaced maxil-  lary segment. Access for the fixation was via the existing laceration. A  maxillary vestibular incision was not placed. (d) The paranasal buttress  was maintained, but loss of bone structure seen at the anterior wall sinus    region. To attain primary healing and to avoid malunion, iliac crest bone  grafts were procured and split into separate pieces. (e) (Right side max-  illa) the green arrows point to the graft segments. Initially the graft seg-  ment was fixed with wire (blue arrow) and was attached to the titanium  plate with screws (the plate was spanned from the zygomatic body to  the displaced main fracture segment). (f) Similar technique done on left  side. (g) Immediate post-operative view after closure of the laceration.  Patient had arch bars fixed and underwent a period of intermaxillary  fixation to help in primary union. Post-operative review showed good  stability for maxilla and the occlusion was maintained    eton: an approach to the management of Le Fort fractures. Plast  Reconstr Surg. 1980;66:54-62.   . Hendrickson M, Clark N, Manson PN, Yaremchuk M, Robertson B,  Slezak S, Crawley W, Vander KC. Palatal fractures: classification,    patterns, and treatment with rigid internal fixation. Plast Reconstr  Surg. 1998;101(2):319-32.    8. Bowley NB, Brown J. Radiology for maxillofacial trauma. In Booth  PW, Schendel SA, Hausamen J-E, editors. Maxillofacial surgery.  Churchill Livingstone Elsevier; 2007. p. 278-9.  9. Manson PN, Markowitz B, Mirvis S, Dunham M, Yaremchuk  M. Toward CT-based facial fracture treatment. Plast Reconstr Surg.  1990;85(2):202-12. Discussion 213-4  10. Gruss JS, Mackinnon SE. Complex maxillary fractures: role of  buttress reconstruction and immediate bone grafts. Plast Reconstr  Surg. 1986;78(1):9-22.  11. Nastri AL, Gurney B. Current concepts in midface fracture manage-  ment. Curr Opin Otolaryngol Head Neck Surg. 2016;24(4):368-75.  12. Marciani RD, Gonty AA. Principles of management of complex  craniofacial trauma. J Oral Maxillofac Surg. 1993;51(5):535—42.  13. Kelly KJ, Manson PN, Vander Kolk CA, Markowitz BL, Dunham  CM, Rumley TO, Crawley WA. Sequencing Le Fort fracture  treatment (Organization of treatment for a panfacial fracture). J  @©Association of Oral and Maxillofacial Surgeons of India Craniofac Surg. 1990;1(4):168-78.  14. Markowitz BL, Manson PN. Panfacial fractures: organization of  Fig. 55.26 (continued) treatment. Clin Plast Surg. 1989;16(1):105-14.  15. Romano JJ, Manson PN, Mirvis SE, Dunham M, Crawley  W. Le Fort fractures without mobility. Plast Reconstr Surg.  References 1990;85(3):355-62.  16. Moss WJ, Kedarisetty S, Jafari A, Schaerer DE, Husseman JW. A   . Marciani RD. Management of midface fractures: fifty years later. J review of hard palate fracture repair techniques. J Oral Maxillofac  Oral Maxillofac Surg. 1993;51(9):960-8. Review Surg. 2016;74(2):328-36. Review   . Rowe and Williams’ maxillofacial injuries (ed 2): Williams JL 17. Chen CH, Wang TY, Tsay PK, Lai JB, Chen CT, Liao HT, Lin  (ed), with 51 contributors, New York: Churchill Livingstone; CH, Chen YR. A 162-case review of palatal fracture: manage-  1994, 1067 pages (2 volumes), illustrated. J Oral Maxillofac Surg. ment strategy from a 10-year experience. Plast Reconstr Surg.  1996;54(3):378. 2008;121(6):2065-73.   . Cunningham LL, Haug RH. Management of maxillary fractures. 18. Cienfuegos R, Sierra E, Ortiz B, Fernandez G. Treatment of palatal  In: Miloro M, Ghali GE, Larson P, Waite P, editors. Peterson’s prin- fractures by osteosynthesis with 2.0-mm locking plates as external  ciples of oral and maxillofacial surgery. BC Decker; 2004. chapter fixator. Craniomaxillofac Trauma Reconstr. 2010;3(4):223-30.  23.1, p. 434-8. 19. Ma D, Guo X, Yao H, Chen J. Transpalatal screw traction: a simple   . Gruss JS, Mackinnon SE. Complex maxillary fractures: role of technique for the management of sagittal fractures of the maxilla  buttress reconstruction and immediate bone grafts. Plast Reconstr and palate. Int J Oral Maxillofac Surg. 2014;43(12):1465-7.   Surg. 1986;78(1):9-22. 20. Manson PN, Glassman D, Vanderkolk C, Petty P, Crawley   . Louis M, Agrawal N, Kaufman M, Truong TA. Midface fractures WA. Rigid stabilization of sagittal fractures of the maxilla and pal-  I. Semin Plast Surg. 2017;31(2):85-93. ate. Plast Reconstr Surg. 1990;85(5):71 1-7.   . Manson PN, Hoopes JE, Su CT. Structural pillars of the facial skel- 21. Cohen SR, Leonard DK, Markowitz BL, Manson PN. Acrylic    splints for dental alignment in complex facial injuries. Ann Plast  Surg. 1993;31(5):406-12.    Open Access This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.  org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropri-  ate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.   The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in  a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.   The zygomaticomaxillary complex (ZMC) refers to the skel-  etal unit [1] formed by the zygomatic bone and maxilla  (Fig. 56.1). These two bones are referred to as a complex,  because of the structural and functional relationship between  them; they articulate with each other over a wider area, and  any traumatic impact on one bone generally influences the  other. This duo complex also constitutes a major part of the  orbit, spanning the infra-orbital rim, lateral wall, and floor.  Hence the ZMC is also termed orbitozygomaticomaxillary  complex [2]. Because of its multiple articulations, various  names are commonly used to describe ZMC fractures such  as “tripod, tetrapod, or pentapod” [3, 4] fractures.   Fractures of the ZMC commonly result in severe cosmetic  and functional deficits because of the prominent anatomical  position of the zygoma and its proximity to adjacent vital  structures such as the globe. Precise reduction and fixation of  these fractures is challenging due to their complex anatomic  form, multiple articulations, and deformation in multiple  planes. The scope of this chapter encompasses the biody-  namics of ZMC fractures, clinical implications, and guide-  lines for successful management.    Electronic Supplementary Material The online version of this chap-  ter (https://doi.org/10.1007/978-98 1-15-1346-6_56) contains supple-  mentary material, which is available to authorized users.    E. Panneerselvam   Department of Oral and Maxillofacial Surgery,  SRM Dental College, Ramapuram, Chennai, Tamil Nadu, India    Department of Orbit and Oculoplasty, Aravind Eye Hospital,  Chennai, Tamil Nadu, India    P. Ravi - B. Sasikala  Department of Oral and Maxillofacial Surgery, SRM Dental  College, Ramapuram, Chennai, Tamil Nadu, India    © The Association of Oral and Maxillofacial Surgeons of India 2021    The term zygoma denotes a “yoke or bar,’ in Greek. Quite aptly,  the zygoma extends as a prominent, sturdy bar across the face,  contributing to its transverse width and anteroposterior projec-  tion. The clinical significance of this bony complex is attributed  to its role in defining facial esthetics and globe function.    The zygoma articulates with four bones [5]; superiorly fron-  tal, medially maxilla, laterally temporal bone, and posteri-  orly sphenoid, through five processes [4] (Fig. 56.1), namely,  the zygomaticotemporal (ZT), zygomaticomaxillary (ZM),  infra-orbital (OR), fronto-zygomatic (FZ), and sphenozygo-  matic (SZ) or zygomaticosphenoid (ZS). These processes are  clinically significant in establishing the three-dimensional  structural integrity of the upper lateral face.   Fractures of the ZMC have been traditionally called the  “tripod or trimalar fractures” because it involved separation  at the three processes of the zygoma—the FZ, IOR, and the  ZM processes (Fig. 56.2a). The terminology was later modi-  fied to “quadripod or quadramalar fracture” to include sepa-  ration at the fourth point of articulation, the ZT process  (Fig. 56.2b). However, the importance of SZ articulation  along the lateral wall of the orbit has been recognized lately,  and, hence, ZMC fracture is currently called a pentapod frac-  ture (Fig. 56.2c), to emphasize the necessity of restoring the  five articulations during fracture management.    ¢ Zygoma and orbit: ZMC forms the lateral and inferior  part of the orbit, protecting as well as supporting the globe  and associated soft tissues. The Whitnall’s tubercle pres-  ent on the zygoma (inferior to the FZ suture) provides    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1-15-1346-6_56    attachment to the suspensory ligament of Lockwood that  maintains the horizontal axis of the globe [6] (Fig. 56.3a).  A fracture line located above the Whitnall’s tubercle leads  to inferior displacement of zygoma as well as the lateral  attachment of Lockwood ligament resulting in anti-  mongoloid slant to the eye (Fig. 56.3b). Thus ZMC frac-  tures greatly influence the structure and function of the  orbit. Further, the contents of the orbit including the  globe, extraocular muscles, and orbital fat are intimately    related to the zygoma and may be affected in fractures of  the ZMC or its surgical manipulation.   ¢ Zygoma and mandible: The zygoma and zygomatic arch  are anatomically close to the coronoid process of the  mandible. Therefore, a fractured zygoma or arch, when  retro/medially positioned, may impede mandibular move-  ments [7]. A displaced and untreated fracture of zygoma/  arch which is in close proximity to the coronoid process  can result in extra-articular ankylosis [8].   e« Zygoma and maxillary sinus: Fractures of the ZMC  (except the isolated zygomatic arch fractures) involve the  maxillary sinus and show features of hemosinus [4] or  sinusitis [3].    The muscles attached to ZMC are the zygomaticus major, zygo-  maticus minor, orbicularis oculi, and masseter [9]. Masseter is  attached to the zygomatic arch on the lateral and inferior aspect  as well as the zygomatic tuberosity (Fig. 56.4a). The downward  displacing forces of the masseter have been considered by many  as the principal cause of post-reduction instability [10].   The temporal fascia attached to the arch superiorly plays  a major role in resisting the downward displacement of frac-  tured ZMC or arch due to the inferior pull of the masseter  (Fig. 56.4b) [1].    The arch is the key parameter for re-establishing the sagittal  projection as well as transverse width of the face [11]. An  arch which is bent outward or inward gets shortened [4].  This leads to retrodisplacement of zygoma resulting in  altered facial width (Fig. 56.5b). It is important to remember    Fig. 56.2 Types of ZMC fractures. (a) Tripod fracture. (b) Tetrapod fracture. (c) Pentapod fracture    Fig.56.3 Relation of suspensory ligament to zygoma. (a) Displacement  of suspensory ligament of Lockwood leading to anti-mongoloid slant.  (b) Clinical appearance of anti-mongoloid slant    that in spite of being referred to as an arch, it does not have  an exaggerated curvature. Therefore, overzealous contouring  during reduction of zygomatic arch fractures can result in  compromised esthetics. The arch is encased by a thick peri-  osteal and fascial envelope which counteracts the displacing  forces of the masseter [1]. However, when the periosteal  envelope is damaged due to high-velocity injuries, the frac-  ture segments show more displacement.    The nerves in close proximity to the ZMC are (1) infra-  orbital nerve and (2) zygomatic nerve [12] (Fig. 56.6a). The  infra-orbital nerve runs along the ION groove and enters the    Fig. 56.4 Displacing forces acting on the zygoma and arch. (a)  Masseter exerting downward force. (b) Temporalis with a superior  vector    ION canal giving off the superior dental plexus of nerves  before exiting through the ION foramen onto the face. Here  it innervates the lower eyelid, lateral aspect of the nose, and  upper lip of the ipsilateral side. The zygomatic nerve which  enters the orbit through the inferior orbital fissure divides  into two branches, the zygomatico-facial and zygomatico-  temporal which emerge onto the face through their respec-  tive foramina. The zygomaticofacial nerve innervates the  skin over the malar area, while the zygomaticotemporal  nerve supplies the skin over the anterior temporal region.  These nerves may be injured due to trauma or during surgery.  The severity of paresthesia which arises is generally propor-  tional to the degree of displacement of a fractured zygoma  [13]. The other nerves whose function may be affected in  ZMC fractures are the optic nerve [14] and facial nerve [15].  Blood vessels of importance related to the ZMC are infra-  orbital artery and vein [16] (Fig. 56.6b) which accompany  the infra-orbital nerve. Uncontrolled forces delivered during  elevation of zygoma may injure these vessels resulting in  severe intra-op bleeding.    Numerous classifications have been proposed for ZMC frac-  tures; this chapter would discuss the most practical ones which  help in understanding the biodynamics of fracture as well as  facilitate quick decision-making regarding the treatment.    ¢ The classification proposed by Rowe and Williams [1]  (Fig. 56.7) is based on the axis of rotation of ZMC and the    > Change in facial dimension in zygomatic arch fractures. (a) Inward bowing of arch. (b) Outward bowing of arch    stability after reduction. Following trauma, the zygoma  may undergo rotation along two axes: vertical axis  extending through the FZ suture and first molar and hori-  zontal axis running across the infra-orbital foramen and  zygomatic arch. According to this classification, fractures  were considered as stable after elevation when they dem-  onstrated (1) arch only fracture with medial displacement  and (2) rotation around vertical axis (medially/laterally),  while fractures were categorized as unstable after reduc-  tion when the following features were observed: (1) arch  only fracture with inferior displacement (Fig. 56.8), (2)  ZMC fracture rotated around horizontal axis (Fig. 5  (3) dislocated en bloc (inferiorly/laterally/medially)  (Fig. a), and (4) comminuted (Fig. ).   This classification provides clinical guidance regard-  ing the stability of fracture after reduction and the neces-  sity for fixation.   e ZMC fractures have also been classified on the basis of  “severity of traumatic impact” [4] into low-, medium-,  and high-energy patterns, as demonstrated on CT; low-  energy type is associated with non-displaced/minimally  displaced “en bloc” fractures, medium-energy type is dis-  placed fractures with or without fragmentation, and high-  energy type is associated with fractures with massive  displacement, comminution, or fragmentation.   e Zing et al.’s [17] classification (Fig. ) is a simple  but practically useful method based on the anatomic site  involved; type Al refers to isolated zygomatic arch frac-    ture, and types A2 and A3 are separation at the FZ suture  and IOR, respectively. Type B is a complete monofrag-  ment type with separation at all five sites of articulation  and type C which is multifragmented.    A special and rare variant of zygoma injuries includes avul-  sion of zygoma [18] (Fig. ). These injuries result from tan-  gentially directed forces with high velocity or greater energy.  The fractured zygomatic fragment characteristically becomes a  non-vascularized-free graft whose management is complex.    The fractures involving the zygomatic arch constitute a sepa-  rate entity.   The various patterns of zygomatic arch fractures have  been described by Ozyazgan et al. [19] (Fig. ) based  on the number of fracture lines and displacement of fracture  fragments:    ¢ Type 1 constitutes the isolated zygomatic arch fractures  which are subdivided into (1) dual fracture (type I A) and  (2) more than two fractures (type I B). This is further clas-  sified into V-shaped (type I B-V) and displaced fracture  (type I B-D).   ¢ Combined zygomatic arch fractures are referred to as type  II, which can present as two variants: single (type II A)    Fig. 56.6 a, b Neurovascular structures related to ZMC fractures. OA,  ophthalmic artery; nb, nasal branch; zmb, zygomatico-malar branch;  vb, vestibular branch    and plural fracture (type II B). Plural fractures are termed  type II B-R when they are approximated or reduced and  type II B-D, when displaced.    Yamamoto et al. classification [20] (Fig. 56.13) dif-  ferentiates fractures based on displacement: type I, no dis-  placement; type II, displacement with bone contact at all  fracture lines; type III, displacement without bone contact  at one fracture line; type IV, displacement without bone  contact at two fracture lines; and type V, comminution or  displacement without bone contact at three or more frac-  ture lines. Honig Merten et al. [21] (H-M classification)  (Fig. 56.14) classified zygomatic arch fractures based on  CT findings as class I which indicated isolated tripod frac-  ture, class II as an isolated stick fracture of the arch, and    class II a combined fracture of the malar bone and the  zygomatic arch.    The clinical assessment of ZMC fractures is performed by a  thorough examination of the face and the eye. As the zygoma  forms an integral part of the orbit (floor and lateral wall), any  trauma to the ZMC may have profound impact on the integ-  rity of the globe and vision [2, 22]. This mandates a primary  ophthalmic examination prior to facial examination.    The globe is meticulously assessed for its form, position, and  function. This is performed by a comprehensive examination  protocol called “8-point eye exam” [23] provided by the  American Academy of Ophthalmology (refer to Chap. 57).    The facial examination should focus on assessment of (1)  facial symmetry and morphology and (2) functions such as  mouth opening, vision, sensory perception, and occlusion.   The clinical characteristics of ZMC fractures [1, 4, 5]  may be divided based on their cosmetic and functional impli-  cations (Box 56.1) .    ¢ Restricted mouth opening  ¢ Malocclusion  ¢ Neurological deficit  — Paresthesia  (i) Infra-orbital nerve  (ii) Zygomaticofacial    A description of clinical features with their associated  pathophysiology is provided below.    Periorbital edema and ecchymosis: The edema and  ecchymosis in ZMC fractures are more dramatic due to  the loose connective tissue in the periorbital region.  Ecchymosis is commonly seen in the circumorbital region  and maxillary buccal sulcus (Fig. 56.15).   Subconjunctival hemorrhage (SCH): Subconjunctival  hemorrhage or hyposphagma (Fig. 56.15) often occurs in  ZMC fractures due to collection of the blood into the sub-  conjunctival space, secondary to hemorrhage from the  surrounding periosteum. Characteristically, SCH in ZMC    fractures does not have a posterior limit in contrast to  SCH due to globe injuries [24]. It is important to note that  SCH without a posterior limit is also seen in skull base  fractures [25].Chemosis and hyphema are also seen in  some cases.   Epistaxis: Occasional epistaxis may be observed due to  escape of pooled blood from the maxillary sinus follow-  ing ZMC fracture. This is typically ipsilateral. Resultant  nasal congestion is a common clinical finding.   Loss of facial prominence: Displacement of zygoma due  to trauma leads to the characteristic flattening of malar  prominence (Fig. 56.16). This is well observed in bird’s  eye and worm’s view. Examination by palpation is done    from behind the patient to detect malar depression.  However, the flattening cannot be appreciated in the pres-  ence of moderate or severe edema.   e Eye signs: The eye signs are a very striking feature of  zygomatic injury especially when rotated and inferiorly  displaced. Inferior displacement of zygoma results in  hypoglobus and an anti-mongoloid slant to the eye  (Fig. 56.3b). Inferior or posterior displacement of the  infra-orbital rim also causes lowering of the lower eyelid  leading to increased scleral show (Fig. 56.17).   are exophthalmos in posteriorly/medially displaced  zygoma (Fig. 56.18a—c) and enophthalmos in laterally  and inferiorly displaced zygoma (Fig. 56.19). En/exoph-  thalmos resulting from ZMC fractures must be differenti-  ated from enophthalmos arising from blow-out fractures  involving the orbital floor. The clinical implications of the  above are explained under “preoperative planning.” Also,  it is important to remember that the traditional assessment  of en/exophthalmos by Hertel’s exophthalmometer does  not reflect the true position of the globe in displaced ZMC  fractures because it uses the orbital rim as a point of refer-  ence. Naugle’s which utilizes supraorbital rim as a refer-  ence is ideal in such cases [26]. However CT evaluation is  the most preferred modality [27] (refer Chap. 57 on  orbital fractures).  Tenderness and step deformity: When edema is severe and  inspectory findings are not conclusive, palpation gives  more details. Tenderness on digital palpation, step defor-  mity at the fronto-zygomatic, zygomatic buttress, and  IOR are good indicators of fracture.    sema in the form of subcutaneous crackling. This occurs  when there is a fracture through a sinus wall which allows  air escape into the facial soft tissues. It usually disappears  spontaneously, in 2-4 days [28]. However, this can be a  potential cause of infection [29].    can arise because of two reasons [30]: (1) mechanical  obstruction to movement of the mandible by a retrodis-  placed zygoma or a fractured zygomatic arch (Fig. 56.20a,  b) and (2) a fractured arch impinging on the temporalis  muscle causing reflex spasm/trismus. Likewise, injury to  the masseter also can lead to trismus.    Fig. 56.9 En bloc and comminuted ZMC fractures. (a) En bloc displacement of the right ZMC. (b) Comminuted ZMC of left side    Fig. 56.10 Zing’s classification of ZMC fractures. (a) arch only (Type A1), (b) separation at fronto-zygomatic suture (Type A2), (c) separation at  infra-orbital rim (Type A3), (d) complete mono-fragment (Type B) and (e) multi-fragment (Type C)    for altered occlusion is the flexing of the ipsilateral  maxillary alveolus leading to premature molar contact  [31]. Paresthesia involving the zygomaticofacial and  zy gomaticotemporal nerves may be present. In rare occur-  rences, injury to the facial nerve leading to paresis has  been observed in severely displaced or high-velocity inju-  ries of the zygoma [15].   ¢ Altered/loss of vision: Binocular diplopia is a common  finding. The diplopia that develops following trauma  can be the result of soft tissue (muscle or periorbital)  entrapment, neuromuscular injury, intra-orbital or intra-  muscular hematoma/edema, or a change in orbital  shape, with displacement of the globe [32]. A forced  duction test (FDT) (Fig. 56.21) would confirm any  physical impediment to ocular motility [4]. Diplopia  due to edema/hematoma resolves in a few days, while  that due to muscle entrapment does not, necessitating  surgical correction.   ¢ Paresthesia: Infra-orbital nerve being closely related to partial loss of vision [33].  the zygoma gets compressed or pulled in displaced or  comminuted ZMC fractures leading to paresthesia along  the lower eyelid, upper lip, and lateral aspect of the nose. 56.5 Imaging for ZMC Fractures  Occasionally, a patient may also have altered sensation  involving the maxillary teeth leading to a perception of Radiological assessment is essential for accurate diagnosis  altered dental occlusion [5]. The other theory put forward and assessment of severity of the fracture.    Plain radiographs [31]: Conventional radiographs con-  tinue to remain the mainstay of imaging at some centers.  Conventional radiographs may also be useful in the post-  operative phase, to assess fracture reduction. However  conventional radiographs are limited by superimposition  of structures.   The commonly used views include the waters view  (37° occipitomental) (Fig. 56.22) which provides good  visualization of the fractured zygoma and helps in com-  paring with the contralateral side. Tracing the McGrigor-  Campbell lines [34] (refer Chap. 55) or the Dolan’s lines    Type Ill  Displacement without bone contact Displacement without Comminution or  at 1 # line bone contact displacement without    at 3 or more # lines  @©Association of Oral and Maxillofacial Surgeons of India    Fig. 56.14 Honig Merten (HM) et al. classification of zygomatic arch fractures    ©Association of Oral and Maxillofacial Surgeons of India Association of Oral and Maxillofacial Surgeons of India    Fig. 56.18 Exophthalmos. (a) Frontal view demonstrating exophthal-  mos and hyperglobus on right side. (b) Basal view of the same patient  showing exophthalmos on right side. (c) Axial CT section demonstrat-  ing exophthalmos of the right eye    ¢ The submentovertex/jug handle view [31] (Fig. 56.23)  offers the best representation of fractures of the arch. Loss  of elephant trunk appearance which is indicative of arch  fracture is well appreciated in this view.    Fig. 56.19 Enophthalmos. (a) Frontal view showing enophthalmos on  left side. (b) Basal view of the same patient showing enophthalmos on  left side. (c) Axial CT section demonstrating enophthalmos of the left  eye    ¢ Computed tomograms: CT remains the gold standard  [31]. It enables a three-dimensional assessment of the  fracture along with demonstration of soft tissue entrap-  ment between the fracture fragments. Identification of  sphenozygomatic diastasis is best appreciated on CT  scans. They also aid in volumetric analysis of the orbital  cavity and deficits of the orbital floor. The features dem-  onstrated in different CT sections are highlighted  (Fig. 56.24a—-d). Figure 56.25 demonstrates CT scan  image with volume rendering, which is useful in assess-  ing the spatial orientation of fractured ZMC.   ¢ USG is a useful tool for diagnosis of ZMC fractures with  high degree of sensitivity for fractures of the arch and  infra-orbital rim with the significant advantage of “zero”  radiation exposure [36].    The role of intra-operative imaging is discussed in the  later segments of the chapter.    Fig. 56.20 Restricted mouth opening in ZMC fractures. (a) noid. Process, blue arrow demonstrating normal space. (b) Fractured  Retrodisplaced zygoma impinging on the coronoid. Yellow arrow dem- _arch impinging on the coronoid (Here, blue arrow demonstrates reduced  onstrating restriction of space between the body of zygoma and coro- space)    Fig. 56.22 Waters view with Dolan’s lines. (A) Orbital line, (B)  Zygomatic line and (C) Maxillary line. The yellow arrows indicate frac-  ture separations noted on the right ZMC    Surgical outcome of ZMC fractures is greatly influenced by  two important factors: (1) choosing the right indications for  intervention and (2) ideal time for surgery. Not all fractures  of the ZMC require surgical intervention. The decision to  intervene should be based on signs and symptoms and pres-  ence of functional impairment (Fig. 56.26).    1. It is not necessary to intervene surgically if the fracture is  incomplete, undisplaced, or minimally displaced with no  compromise in esthetics or function. But such patients  must be advised to follow soft, non-chewy diet for 2-6  weeks and monitored to identify displacement [38].   2. Indications for surgery include (1) presence of cosmetic  defects in the form of facial deformity, loss of lower eyelid  support, or ocular dystopia; (2) functional deficits such as  limitation of mouth opening, sensory nerve deficit, and  impaired ocular movements; and (3) ZMC fracture associ-  ated with OCR reflex in children (please refer to Chap. 57).   3. Postponement of surgical intervention is considered when  the general neurologic status of the patient is questionable.   4. Surgical intervention is relatively contraindicated when  the involved side has the only seeing eye. In a patient  willing for surgery, “potential loss of vision” has to be  included in the informed consent.    ZMC fractures are not emergencies, and treatment can be  delayed, if necessary.    ¢ When the decision is “no immediate intervention,” sur-  gery may be postponed for up to 2 weeks, following  which a reassessment may be made.   ¢ When the indications are questionable, for example, pres-  ence of severe edema or fractures with minimal displace-  ment, it is advisable to wait for the edema to subside so  that the deformity may be assessed better.   ¢ When the indications are definite, immediate intervention  provides better outcomes due to minimal soft tissue scar-  ring and easier reduction of fractures.    Management of ZMC fractures is aimed at achieving the sur-  gical objectives highlighted in Box 56.3 [37].   e Restoration of mandibular range of motion  Mouth opening of 40 mm, excursion — 4-6 mm    ZMC fractures may be categorized into three classes based on  their propensity to develop postsurgical infection: clean frac-  tures (isolated arch fractures), clean-contaminated (ZMC frac-  tures compound into the antrum), and dirty (fracture which is  open to exterior). While type three fractures require regular  antibiotic prophylaxis, types 1 and 2 show minimal rates of  infection and may either need “no” antibiotic prophylaxis [40]  or a modified single-day postsurgical regimen [41].    tions due to lack of objective intra-operative measures to  assess reduction. This may be overcome with accurate pre-    Fig. 56.24 CT scan of patient with left ZMC fracture. (a) Axial view  demonstrating overriding of fracture fragments at SZ suture. (b) Axial  section demonstrating fracture at the IOR and buckling of arch. (c)  Coronal section showing separation at the FZ and ZM sutures with    operative planning which helps in realizing surgical objec-  tives in a predictable manner.  Preoperative planning includes three vital steps:    medial displacement of the body of zygoma. (d) Sagittal section dem-  onstrating posterior displacement of IOR and large blow-out fracture of  orbital floor    Proper CT evaluation is absolutely essential for choosing  the ideal treatment; CT plays a very important role in dif-  ferentiating en/exophthalmos due to ZMC fractures from  those due to orbital fractures. This helps in arriving at a  decision regarding internal orbit reconstruction (Box 56.4).    Enophthalmos in  Enophthalmos ZMC +orbit  in ZMC fracture  Relative Absolute  Etiology Change in globe Change in globe  position due to position due to  displaced zygoma fracture of orbital  floor  Surgical Restoration of orbital Restoration of  management rims by reduction and orbital rims by  fixation of ZMC reduction of ZMC  fracture alone fracture as well as    The process begins with obtaining CT scans of the patient  with minimum slice thickness of 0.6 mm. This is followed by  two different sequences of workflow (Fig. 56.27) which are  described below.   patient. There are two methods by which this can be  done.   1. STL model with the actual deformity: This model  presents the post-traumatic deformity, as observed  clinically. A routine model surgery is then per-  formed, by which the displaced fragments are cut  and repositioned to obtain optimal anatomical form.    POSTPONE  Questionable neurologic status (GCS)  Diminished vision in the opposite eye    The repositioned fragments are stabilized temporar-  ily with wax. The fixation devices (miniplates) are  then pre-contoured over the model. Such pre-  contoured implants are used to guide intra-operative  fracture reduction as well as fixation. Figure 56.28a—d  demonstrates the sequence described.   STL model after mirroring: CT scan is used to  generate a virtual model wherein the normal side is  mirrored onto the fractured side. The virtual model is  used to print a physical model which demonstrates  the skull which is bilaterally symmetrical, mimick-  ing ideal reduction status. Similar to the earlier  method, implants for fixation are pre-contoured over  this model to help achieve optimal results intra-oper-  atively. Figure 56.29a—d demonstrates a similar clin-  ical scenario.   This method utilizes the complete spectrum of computer-  assisted surgical planning. A CT scan is obtained to create  a virtual model on which the entire surgical sequence of  reduction is performed and on which the stents for intra-  operative guidance are designed. Intra-operative stents are  printed from these virtual designs. There is no physical  “handheld” model here (Refer Chap. 41).    In the case of a unilateral ZMC fracture, the normal  side is mirrored to the fractured side to obtain bilat-  eral symmetry. CAS technology is then utilized to  design “guidance stents” on the mirrored side. These  stents can be utilized intra-operatively to (1) verify  ideal reduction position in primary trauma or (2)  design the osteotomy and repositioning, in second-  ary corrections. Another important advancement in  recent years is the design and printing of  “patient-specific implants” (PSI) using virtual plan-  ning. These customized fixation devices double up  as guidance stents also (Refer Fig. 57.54).   In bilateral ZMC fractures [43], mirroring is not an  option, and the ideal sequencing for such cases is  discussed in Sect. 56.14, of this chapter.    Fig. 56.28 Model surgery for pre-contouring of implants. (a) CT image demonstrating fractured ZMC of right side. (b) STL model demonstrating  deformity. (c) Repositioning of fracture fragments to anatomical position. (d) Pre-contouring of implants    Fig. 56.29 Use of mirrored models for pre-contouring of implants. (a) 3D CT image of fracture. (b) Mirroring of zygoma of normal side to frac-  tured side. (d) Generation of mirrored STL model and pre-contouring of implants    Li et al. [44] have described a technique for 3D simulation  and prediction of soft tissue—outcome analysis in ZMC  fractures. This process enables prediction of postoperative  soft tissue changes in patients with ZMC fractures who are  indicated for primary/secondary surgical interventions. The  planning involves utilization of CT data and 3D stereopho-  tography for the analysis. The technique may also be utilized  for evaluation of postsurgical results.   2. The surgical approach for reduction may be different  from that for fixation.    Fracture reduction may be done either by direct or indi-  rect method, and the approaches may be extraoral or intra-  oral [1].    The indirect method is a blind technique where fracture is  reduced without exposure of the fracture site (e.g., Gillies  reduction), while direct method involves reduction of the  fracture under direct visualization (e.g., coronal approach to  reduce arch fracture). The differences between the two meth-  ods are shown in Fig. 56.30. However, indirect method is  more commonly practiced. Open method is resorted to when  the ZMC fracture is (1) severely displaced, (2) complex or  comminuted, (3) when stable reduction is doubtful, and (4)  there is a need for internal orbit reconstruction. However, no  “single technique” is superior, and sometimes, a combina-  tion of techniques is more effective.    The extraoral reduction techniques may be either percutane-  ous, temporal, or endoscopic [1, 45].    Temporal approach [46], commonly called the Gillie’s  (Figs. 56.3la—f and 56.32a), is the most popular method  of ZMC reduction. This approach is favored because the  incision is placed within the hairline which does not leave  a visible scar. It also offers a very predictable force during  reduction and may be used for reduction of both the arch    as well as the zygoma. The technique is based on the ana-  tomical basis that the plane between the temporalis fascia  and the temporalis muscle offers direct access to the  zygomatic arch and zygoma. The only contraindication to  this approach is the presence of concomitant temporal  bone fracture. The incision is placed at a level 2 cm above  the helix of the ear, paralleling the anterior branch of the  superficial temporal artery, well within the hairline  (Fig. 56.33). Dissection is carried down through the skin,  subcutaneous tissue, and galea aponeurotica (temporopa-  rietal fascia—TPF) to reach the temporalis fascia.    temporal fascia exposing temporalis muscle. (e) Developing plane of  elevation with periosteal elevator. (f) Placement of Rowe’s zygomatic  elevator for elevation    Fig. 56.31 Gillies temporal approach. (a) Marking of incision parallel  to frontal branch of superficial temporal artery. (b) Placement of inci-  sion. (c) Exposure of deep temporal fascia. (d) Incision through deep    An incision is made through the temporalis fascia to  reveal the underlying temporalis muscle. A Howarth’s  elevator is inserted between the temporalis fascia and the  muscle, to create a plane for the zygomatic elevator. Two  types of zygomatic elevators, namely, the Bristow’s and  Rowe’s (Fig. 56.34a), are commonly used; the Bristow’ s  has a single flat and elongated working tip attached to a  handle and is used like a spatula for elevation, while the  Rowe’s elevator has an additional arm attached to the  working tip which serves two purposes: (1) to provide the  necessary countertraction during elevation so that it  relieves the fulcrum off the temporal bone and (2) to eval-  uate the approximate depth of insertion of the working tip  when inserted into the tissue. The zygomatic elevator is  positioned in the plane created, directed inferiorly to  reach the deeper surface of the zygoma and carefully  elevated, while an ironing motion is used to smoothen the    collapsed arch form. Care is taken not to lever the elevator  against the skull (Video 56.1).   1. It is good practice to keep a roll of gauze under the  zygomatic elevator to prevent injury to the temporal  bone.   2. Instead of extensive shaving of the temporal hair  for a Gille’s approach, a small patch (lcm by 3cm)  of shaving/close trimming of hair can be done for  better cosmesis.    Percutaneous methods make use of a minimal facial skin  incision, usually right over the zygoma or the lateral brow  (Dingman’s method) through which instruments may be  inserted to manipulate and elevate the displaced zygoma.    Fig. 56.32 Different approaches for reduction of fractured ZMC. (a) Gillie’s. (b) Poswillo. (c) Dingman. (d) Balasubramaniam. (e) Quinn    made at the point of intersection of two imaginary  lines—a horizontal from the base of the nose and a  vertical from lateral canthus (Fig. 56.35a, b). The inci-  sion is oriented along the skin crease, just enough for a  Poswillo hook [47] to be engaged underneath the body  of the zygoma (Fig. 56.32b and Fig. 56.34b). And the  impacted zygoma is pulled upward or outward. Skin  incision is closed with a single suture. Reduction  through a zygoma approach may also be performed by  using a Carroll-Girard screw [48]/universal bone  reduction screw (Fig. 56.34c).   This technique is performed through a standard lat-  eral brow approach where the fracture is visualized by  a direct approach to the bone after incising through the  skin, subcutaneous tissue, and periosteum. An elevator  is then passed laterally and posterior to the orbital rim  into the temporal fossa. The temporal aponeurosis  (attachment of the deep temporal fascia to the lateral  orbital rim) is incised, and the elevator is passed    an upward, forward, and outward fashion. The original  description by Dingman utilized trans-osseous wiring  for stabilization of the front-zygomatic suture.  However current methods incorporate the use of mini-  plate osteosynthesis through this approach.   This approach uses a vestibular incision behind the  zygomatic buttress. A Howarth’s periosteal elevator is  inserted in a supraperiosteal plane to engage the infratem-  poral surface of the zygoma. Reduction is achieved with  an upward, forward, and outwardly directed force. When  greater force is needed to elevate as in impacted zygomas    Temporoparietal fascia (SMAS  @©Association of Oral and Maxillofacial Surgeons of India    Fig. 56.33 Gillie’s correct plane for elevation. It is important to under-  stand that the deep temporal fascia divides into two, to enclose the  zygomatic arch and the fat above, approximately 2 cm above the arch.  An incision placed too low may mislead the young surgeon into the fat  plane (b, lateral to the arch) rather than the subfascial plane (a, medial  to the arch) (Also refer Fig. 85.1a)    or delayed presentation, a Bristow’s/Rowe’s zygomatic  elevator (Fig. 56.36) or the arm of an upper anterior for-  ceps may be used. The technique offers more mechanical  advantage than the extraoral method; less force is needed  to elevate, because the force is directed entirely at the cen-  ter of the zygomatic body, which is considered more  effective.   ¢ Quinn’s procedure (lateral coronoid approach) [51]  (Fig. 56.32e) employs an incision over the anterior border  of the ramus. An elevator is inserted in a supraperiosteal  plane, lateral to the coronoid process and paralleling the  temporalis tendon to reach the medial surface of the zygo-  matic arch. Elevation of the arch may be done in an iron-  ing fashion.    Elevation of the depressed arch is usually performed in an  indirect manner, using the Gillie’s technique. However  numerous techniques have been advocated in literature.  These include the “roller-coaster” lateral brow technique  [52] and methods using percutaneous towel clip [53], trac-  tion suture [54], Foley’s catheter [55], K wire [56], and  Dingman elevator [57] to restitute the arch anatomy.    Fig. 56.34 Instruments for reduction. (a) Rowe’s . (b) Poswillo hook.  (c) Universal bone reduction screw    The intra-operative assessment of reduction is a critical step  in zygoma management, especially in closed reduction. The  methods commonly used are (1) clinical assessment, (2)  imaging, and (3) use of prefabricated guides/stents.    1. Clinical assessment is usually done by eyeballing, com-  paring with the normal side or palpation of the rims for  steps. However, the adequacy of reduction may be diffi-  cult to assess intra-operatively because of edema as well  as patient position. Audible click during manipulation is  also indicative of reduction [58]. Surgical exposure of  multiple suture sites is the other method to confirm reduc-  tion [59] but is less favored because of surgical morbidity.  However, exposure at all sites of articulation is not  required; two sites are considered perfect indicators of  accurate reduction [5] (Box 56.5).   2. Intra-operative imaging [58] such as C-arm [60]  (Fig. 56.37a, b), CT [59], O arm [61], or endoscopes [45]  are valuable guides in confirming reduction of ZMC frac-  tures. However, use of intra-op imaging other than  endoscopes mandates use of lead aprons by operating  room personnel to prevent radiation exposure.   3. Prefabricated guides/ stents [62] are valid tools which  ensure accuracy of reduction, intra-operatively.    ert SNE i  ©Association of Oral and Maxillofacial Surgeons of India    Fig. 56.35 Percutaneous reduction with Poswillo’s technique. (a) Marking on skin. (b) Percutaneous insertion of bone hook    Manipulation of zygoma during reduction has been known  to cause certain complications such as bleeding from  infra-orbital vessels [16]. Use of controlled force during  indirect reduction greatly reduces such complications. It  is prudent to watch out for stimulation of Oculocardiac  reflex (OCR) [63] as described later in the text. OCR may  also be prevented by administering regional blocks before  elevation [64].   Once the reduction is completed and found satisfactory,  the fracture fragments need to be maintained in the reduced  state. A Zimmer splint [65] (preformed aluminum splint with  foam on the undersurface) may be adapted to the reduced  arch and secured with sutures. It is maintained in situ for 2—3  weeks.   Finally, it is mandatory to do a force duction test (FDT)  after elevation of zygoma [5] (Box 56.6).    During reduction of ZMC fractures, as the fractured  bones get realigned to normal anatomical position,  entrapment of surrounding soft tissue or muscles may  occur between the fragments   This may lead to port-surgical diplopia, necessitat-  ing a surgical revisit.    Fig. 56.37 Intra-operative assessment of reduction using C-arm. (a) Intra-operative positioning of C-arm. (b) Image demonstrating zygomatic    Fixation needs of ZMC fractures depend on the post-  reduction stability. Classification of fracture patterns by  Rowe and Williams [1] provides guidance on assessment  of fracture stability after reduction. Any fracture classified  as stable after reduction does not require fixation, while  those considered unstable, mandate fixation. However, a  practical method would be to apply moderate digital pres-  sure on the malar eminence after reduction. Displacement  secondary to this maneuver, requires fixation [59]. The  algorithm proposed by Rodrigo and Belini et al. is also a  practical guide to manage ZMC fractures which are not  associated with orbital component [3]. For ZMC fractures  with orbital involvement, Ellis and Perez advocate guide-  lines for orbital reconstruction based on CT evaluation.  Most of the studies indicate increase of fixation points  from | to 2, 3, and 4 points based on the status of intra-  operative stability after reduction. Involvement of orbit  leading to changes in intra-orbital volume requires orbital  reconstruction [59].    The current dictum is “any zygoma which when fractured  and displaced must be fixed” [37]. The objectives are to  achieve a 3D reconstruction (transverse width, vertical  height, and anteroposterior projection) and establish the but-  tresses. Attention needs to be given to the order of restoration  [66, 67]. The results of various biomechanical experiments  indicate that the vertical buttress needs to be fixed first, to  restore the facial height. Then, the anteroposterior projection  may be achieved by restoring the arch (Box 56.7).    Surgical approaches for ZMC fixation are chosen based on  the fracture pattern and fixation needs. A single or multiple    incision may be used for the surgical exposure of ZMC frac-  tures [30, 68, 69].    ¢ Cutaneous (upper eyelid, lateral brow, subciliary,  subtarsal, infra-orbital, preauricular, and coronal  incisions)    The list of incisions and the exposure achieved (green  shaded areas on Fig. 56.38) by each are highlighted in Box  56.8 (Fig. 56.38)   The following is a description of the various incisions  used to access the fixation points in ZMC fractures. It is  important to take adequate measures for globe protection  while placing any periorbital incisions [70]. The commonly  followed methods include either a temporary tarsorrhaphy  (Fig. 56.39) or a corneal shield (Fig. 56.40). The tarsorrha-  phy also offers the additional advantage of being used as a  retraction suture during surgery.   The lateral brow incision is otherwise called as “in the brow”  incision and offers a fast and direct access to the fronto-  zygomatic suture and lateral part of the supraorbital rim. The  extensions for the incision must be well within the eyebrow  which provides an ideal camouflage (Fig. 56.41a). However,  this incision may not be ideal in people who are cosmetically  inclined to maintain a higher eyebrow. Absence of any  important neurovascular structures in this area makes this  incision easy to perform, even by beginners.   After infiltration of LA solution containing vasoconstric-  tor, a 2 cm long incision is placed along the curve of the    Fig. 56.41 Periorbital incisions for FZ suture. (a) Lateral brow inci-  sion. (b) Lateral brow extension (shown in dotted lines). (c) Upper lid  blepharoplasty    superolateral part of the orbital rim. Care is taken to incline  the blade parallel to the hair so that the shafts are not tran-  sected. Failure to do so may cause linear alopecia along the  incision line, which may be unaesthetic. Incision is carried  through the skin, subcutaneous tissue, and the orbicularis  oculi muscle. The flap is undermined in the supraperiosteal  plane to permit ease of retraction. A periosteal incision is  then placed above the fronto-zygomatic suture for reduction  and fixation (Fig. 56.42a, b).   When additional exposure is needed on the medial aspect,  the incision is extended up to the supraorbital nerve. For  additional inferior extension, a gradual 90° turn into the    crow’s feet wrinkle which is restricted to the skin only, is  utilized to provide a much wider access [70] (Fig. 56.41b).  This extension must remain 6 mm superior to the lateral can-  thus. Inferior limit of the incision along the lateral orbital rim  should not cross the RSTL (resting skin tension lines) to  avoid unaesthetic scars.   Closure is performed in layers with approximation of the  periosteum and subcutaneous tissues (Video 56.2).   The upper lid blepharoplasty incision is otherwise called as  the supratarsal fold or upper eyelid crease incision. It offers  the most esthetically favorable approach to the fronto-  zygomatic suture region. The incision is made along the eye-  lid crease, 10 mm above the free margin of the eyelid  (Fig. 56.41c). As the incision extends laterally, it should be at  least 6 mm above the lateral canthus. When eyelid anatomy  is distorted with edema or hematoma, the contralateral lid  crease measurements are used to mark the incision.   The incision is placed through the skin and muscle and is  raised as a skin-muscle flap for good viability of the overly-  ing skin. The plane of dissection is below the orbicularis  oculi in a superior and lateral fashion to reach the periosteum  (Fig. 56.43a, b). The periosteum is sharply incised to expose  the bone underneath. Further dissection along the bony mar-  gins is strictly subperiosteal; any violation of the periosteum  may cause herniation of the lacrimal gland which is present  in the superolateral concavity of the orbit. Closure of the  incision is done in layers, starting with periosteum, followed  by the orbicularis oculi, and the skin.   An important advantage of the upper lid blepharoplasty  incision is the extensive access it offers to the entire supero-  lateral aspect of the orbit. It also permits good visualization  and access to the spheno-zygomatic suture which is the most  important indicator of reduction of ZMC fractures.    Fig. 56.43 Upper lid blepharoplasty intra-operative. (a) Marking. (b) Exposure demonstrating ORIF    56.9.3.3 Subciliary Incision [71, 72] (Figs. 56.38,  56.44a and 56.45a, b)   along with the entire orbital floor. This may be a very useful   The skin incision is placed along the entire length of the  lower eyelid, 2 mm below the level of the eye lashes to con-  ceal the future scar.   The incision must not be extended more than 2 cm lateral  to the lateral canthal ligament. This prevents any inadvertent  damage to the temporal branch of the facial nerve which is  present about 3 cm lateral to the lateral canthal ligament.   Once the skin is incised, the dissection may proceed in  three different ways [30, 70] (Fig. 56.45b) (Box 56.9):    (i) “Skin-alone” flap technique where the plane of dissec-  tion is along the subcutaneous plane between the skin of    Skin-  muscle Stepped  Skin flap flap skin-muscle flap  Skin incision 2mmbelow 2mm 2 mm below the  the cilia below the — cilia  cilia  Muscle Just below Same level 2-3 mm below  incision the infra- as skin the skin incision  orbital rim incision  Periosteum Just below Just below Just below the  incision the infra- the infra-orbital rim  orbital rim infra-  orbital rim  Plane of Between skin Between © Stepped  dissection and orbicularis °¢ Between skin  orbicularis muscle and orbicularis  muscle and muscle in  septum pre-tarsal  region  ¢ Between  orbicularis  muscle and  septum—  inferior to the  tarsal region  Preservation Preserved Incised Preserved  of pre- tarsal  fibers of  orbicularis  oculi  Complications Skin Septal Lesser incidence  buttonholing, perforation of complications  discoloration Ectropion  Lid  shortening  Scleral  show    Fig. 56.44 Lower eyelid incisions. (a) Subciliary. (b) Extended sub-  ciliary showing area of exposure shaded. (c) Subtarsal incision. (d)  Infra orbital    the eyelid and the orbicularis oculi. On reaching the  facial surface of the infra-orbital rim, the orbicularis  muscle along with the periosteum is incised to reach the  rim. The periosteal incision is generally placed at least  3-4 mm below the level of the infra-orbital rim  (Fig. 56.45a and 56.45b1).  “Skin-muscle” technique: the incision is carried down  from the skin into the pre-tarsal fibers of the orbicularis  oculi, and the flap is dissected along the plane deep to  the muscle but superficial to the tarsal plate. The dis-  section is then carried out superficial to the orbital sep-  tum till the rim is reached. Exposure of the rim is  performed after sharp dissection of the periosteum just  below the level of the rim (Fig. 56.45b2).  “Step” approach is performed in two different levels  and is considered the best approach as it prevents most  of the complications which are associated with the two  former approaches. The incision is first placed through  the skin, and the plane of dissection is carried in the  subcutaneous plane, maintaining the pre-tarsal fibers  of the orbicularis oculi. As the lower end of the tarsal  plate is reached, the orbicularis oculi muscle is divided,  and the plane is changed to include the muscle along  with the skin as a “skin-muscle” flap (Fig. 56.45b3).  The development of a skin-alone flap at the marginal  level and a “skin-muscle” flap at the subtarsal level cre-  ates a step in the plane of dissection. The dissection then  proceeds caudally toward the infra-orbital rim in a sub-  muscular plane superficial to the orbital septum. On  reaching the rim, the periosteum is incised sharply about  34 mm below the level of the rim on the facial aspect.    Fig. 56.45 Lower eyelid incisions—sagittal view. (a) Subciliary, sub tarsal and infra-orbital (b) Variants of sub-ciliary incision    The incision of the periosteum at this level not only helps  preserve the attachment of the orbital septum along the  rim margin but also lies above the level of the infra-orbital  foramen which is seen about 7-8 mm below the level of  the rim. Dissection of the periosteum can be performed  along the entire length of the infra-orbital rim, anterior  maxilla, and the zygoma to provide excellent exposure.    Advantages of the stepped approach include (1) mini-  mal chances of buttonholing or darkening of the skin  due to vascular compromise (2) lesser incidence of  ectropion and entropion (3) reduced scarring at the  eyelid margins due to preservation of the pre-tarsal  orbicularis oculi fibers.    The differences between the three variants of subciliary  incision are highlighted in Box 56.9 (Figs. 56.45b).   After placing a standard subciliary incision, supraperiosteal  dissection is performed along the lateral orbital rim in the  cephalic direction till the FZ suture or a few millimeters  beyond (Figs. 56.44b and 56.46). This releases the skin flap  and makes it amenable to easy retraction to reach the FZ  region. The periosteum is then divided in the center of the  lateral orbital rim along its length. In most cases the lateral  canthal ligament may be stripped in a subperiosteal fashion  to facilitate comfortable access to the FZ suture. This  approach may be used to avoid an additional incision for  exposure of the FZ suture.   56.44c and 56.47)  Subtarsal or mid-lid incision was also described by Converse.  The incision is marked 5—7 mm below the inferior lid margin  corresponding to the lower border of the tarsal plate, along    the subtarsal crease (Fig. 56.47). The lateral extension of the  incision may be extended up to 2 cm beyond the lateral can-  thal ligament similar to the subciliary incision, along one of  the resting skin tension lines. The incision is made through  the skin and subcutaneous tissue. The pre-septal fibers of the  orbicularis oculi are also divided at the same level, and the  plane of dissection is maintained superficial to the orbital sep-  tum. The dissection is carried out caudally to reach the infra-  orbital rim, and the periosteum is divided below the level of  the rim on the anterior surface of the maxilla and zygoma.   The subtarsal approach is favored more than the subcili-  ary [73] due to its easier technique and lesser incidence of  complications (Box 56.10).    Fig. 56.48 Figure demonstrates use of frost suture for ZMC fracture  approached by transconjunctival and upper lid blepharoplasty incision.  Technique for frost suture. A 4-0/5-0 nonabsorbable suture on a 3/8th  circle needle is passed to engage the inferior tarsal plate, at the middle  of the lower eyelid margin. The suture is taken either through the gray  line or through the pre-tarsal skin to include the skin, orbicularis, and  the tarsus. Appropriate tension is applied in superior direction by the  anchoring the suture ends, to the supraorbital skin, 5 mm above the  eyebrow using adhesive tapes    An important consideration following lower eyelid  approaches is the application of the “frost suture” [74] (tem-  porary lower eyelid suspension suture) (Fig. 56.48), to pre-  vent postoperative ectropion. Frost suture also permits  visualization of the globe in the postoperative phase, when  required (Refer Fig 11.13).   Nevertheless, lower rim incisions are often associated  with postoperative ectropion and scleral show. While scleral  show/lid traction refers to abnormal exposure of sclera  (1 mm or more) with contact between bulbar conjunctiva and  the lid, ectropion refers to eyelid eversion with no contact  between bulbar conjunctiva and lid [75]. Ectropion requires  correction for cosmetic reasons as well as functional prob-  lems arising from keratinization of exposed conjunctiva.  Treatment varies from conservative modalities to surgical  procedures [76, 77] (Box 56.11).    ¢ Conservative measures  Corneal protection measures; artificial tears, oint-  ment, temporary tarsorrhaphy   ¢ Surgical procedures  Release of cicatrization, sutures,  grafts, cartilage grafts, rotation flaps   and 56.44d)  This is performed as an incision which simultaneously  divides the skin, orbicularis muscle, and periosteum, along  infra-orbital rim. Though the infra-orbital incision offers the    most direct approach to the infra-orbital rim and orbital floor,  it is seldom preferred in contemporary surgery due to the  unsightly postoperative scar and prolonged edema of the  lower lid region due to disruption of lymphatic drainage.   (Figs. 56.38 and 56.49)  Transconjunctival incision has gained popularity because it  completely negates the unesthetic scarring associated with  skin incisions. This incision offers good access to the infra-  orbital rim and SZ regions with either a pre-septal or retro-  septal approach. Refer to the Chap. 57 for a detailed  description of the approach. The modified transconjunctival  incision with a cutaneous Y extension when combined with  lateral canthotomy offers excellent exposure to the IOR, SZ,  as well as the FZ region [80-82]. The complications of trans-  conjunctival incisions include entropion [82], in-curling of  lashes (trichiasis) [83], or growth of the eyelashes in two lay-  ers (distichiasis) [84]. Malposed lateral canthus has also  been observed following improper repositioning of the lat-  eral canthus after canthotomy [82].   The vestibular incision is the most frequently used approach  to access the ZM buttress. The popularity is due to its appli-  cation for reduction of ZMC fracture as well as fixation at the  ZM buttress. Refer to the Chap. 55 for description of the  technique. The author of this chapter (EP) uses the vestibular  approach to also fix the zygomatic arch fractures which over-  ride at the zygomaticotemporal suture, with transbuccal  instrumentation (transoral arch fixation technique) (Refer to  recent trends section 56.16).    56.9.3.9 Preauricular [86] (Figs. 56.38, 56.51,  53.17a, b and 65.6) (Refer Video on pre  auricular approach in Chap. 53)  Preauricular incision is useful for open reduction and fixa-  tion of arch fractures. After the routine skin incision, adopt-  ing the deep subfascial approach provides better protection  to the facial nerve as compared to the other commonly used  approaches, namely, the subfascial and suprafascial proce-  dures [87]. Figure 56.51 demonstrates the use of preauricular  incision with deep subfascial dissection to expose a mal-  united zygomatic arch fracture.   Tessier introduced the use of coronal incision to access the  superior and lateral orbits bilaterally along with naso-orbito-  ethmoid complex in congenital facial reconstruction. The  approach can be extended with a preauricular incision to  include the exposure of the zygomatic body and the arches  bilaterally. This incision also facilitates the temporal  approach to the SZ suture [82]. Disadvantages of the  approach include the extensive length of incision, dissection,  temporal hollowing, scar alopecia, risk of injury to the supra-  orbital nerve, and temporal branch of the facial nerve.    Three basic fixation methods are available for ZMC  fractures [1] (Table 56.1):    The trend has gradually shifted from nonrigid fixation  methods such as trans-osseous wiring, external pin fixation,  and K wires to functionally rigid fixation methods including    Fig. 56.52 Coronal approach, intra-operative. (a) Exposure of arch demonstrating fractured zygomatic arch and FZ region (yellow arrows). (b)  Arch after reduction and fixation at ZT and FZ region    miniplates and compressive screws. However, some of the  nonrigid fixation modalities are still applicable in certain  clinical situations. A brief description of all fixation methods  is provided below along with their indications and  limitations.    Trans-osseous wiring using stainless steel wires is rarely  used in current practice due to its nonrigid mode of fixa-  tion that compromises post-reduction stability. However,  it still remains a useful technique for fracture reduction by  traction, especially at the FZ and IOR. The advantages  include minimal periosteal stripping and lesser hardware  as compared to use of miniplates and screws.   relapse potential and increased possibility of infection.  Antral packing may be done either with a roller gauze   lar. The anterolateral wall of the maxilla is exposed by a   tion of the fragments. A trans-nasal antrostomy port is  created in the inferior meatus. (refer Sect. 24.10, Fig.   — The medicated ribbon gauze pack is introduced into  the antrum through trans-nasal antrostomy, and one  end of the gauze is packed tight in the antrum under  direct visualization through the vestibular incision.  The oral layer is closed, once the desired level of pack-  ing is achieved. The other end which is free is pulled  out through the nostril and taped to the cheek. This is  later used to retrieve the pack once the healing phase is  complete.   — The inflatable balloon is positioned within the sinus  cavity in a similar manner and verified through the  vestibular approach. The balloon is then inflated  with about 20cc of saline till adequate support is  obtained for the reduced fragments. The vestibular  approach is then closed meticulously without dam-  aging the balloon. The balloon is left in situ for the  fracture to heal. Removal is accomplished by deflat-  ing the balloon and pulling it out through the antros-  tomy port.    (Fig. 56.53a—c) are still popular in some units as they  serve as tools of reduction as well as fixation. But these  techniques are associated with cutaneous scars and poor  patience compliance due to the transcutaneous presence  of pins. The noteworthy advantages of external pin fixa-  tion are the reduced cost and the possibility of adjusting  the fixation in the immediate postoperative period.  K wires and Steinmann pins constitute an indirect method  of fixation whereby the fractured zygomatic bone is fixed  in a secure fashion to another stable point in the craniofa-  cial skeleton. Such indirect anchorage may be obtained by  using pins (1) to secure the fractured fragment to other  stable bones or (2) to provide anchorage for connectors of  an external fixator. The different techniques of indirect  fixation that have been advocated for management of  ZMC fractures include (Fig. 56.54):  (A) Trans-zygomatic—by this technique, the zygoma is  first reduced through an intraoral approach to    Fig. 56.53 Armamentarium  for indirect fixation. (a) K  wire. (b) Steinmann pin. (c)  Manual K-wire driver    enable adequate visualization of the entry of K  wire/pin thorough the vestibular incision. The  reduced ZMC is then stabilized by transfixing it to  the contralateral zygoma using a K wire. The K  wire is passed from the body of the reduced zygoma  in a trans-facial fashion to engage the stable cortex  of the contralateral zygoma by the use of a K-wire  driver.  Naso-zygomatic—this method involves the use of a  K wire to stabilize the reduced ZMC to the frontal  process of the maxilla on the contralateral side. The  wire is driven from the frontal process of the max-  illa in a forward and downward direction to engage  the antral surface of the zygomatic body. This must  be done with care to prevent any inadvertent dam-  age to the nasolacrimal duct which lies adjacent to  the path of pin.  Zygomatico-palatal—this procedure involves fixa-  tion of the reduced ZMC to the palatal surface of  the contralateral maxilla, by passing a K wire  through the reduced ZMC in a downward and  oblique direction.   Indirect fixation may also be performed by the  use of external fixators or a halo frame that can be    attached to pins for anchorage. This may include  the techniques described below.   Fronto-zygomatic fixation: This technique involves  the use of a Steinmann pin for anchorage onto the  reduced ZMC fragment. The pin is then anchored to  another pin which is fixed on the stable orbital pro-  cess of the frontal bone by the use of an external  fixator device.   Cranio-zygomatic fixation: This method is per-  formed in the same fashion as the fronto-zygomatic  method, except that the stable component for  anchorage is from a halo frame that is cranially  anchored, rather than a single pin on the frontal  bone.    Lag screws [91] have been found to be an effective alter-  native at the FZ region because of the additional stability  offered by interfragmentary compression. But this tech-  nique requires adequate bone stock for fixation.   Micro screws [92]: Micro screws are 2 mm screws which  are used to fix sagittal zygomatic fractures by using the  lag screw technique. These screws also reduce hardware  (Fig. 56.55a—c).   Miniplates [3, 4]: The principal method of fixation is  miniplate osteosynthesis. Miniplates are chosen based on   Shape of plates: The plates are chosen according to the  contour of the bone that needs to be fixed; L plate for the  ZM suture and a curved plate for the IOR.   Presence of bone loss: Comminuted fractures or bone  loss may result in sagging of overlying soft tissues, espe-  cially in the ZM buttress region. This may be negated by  using a broad mesh that bridges defects.   Biological considerations: Care must be taken to pro-  tect the roots, infra-orbital nerve and eye during fixation.  In regions where the skin is thin, low-profile plates are  preferred, 2 mm system for the ZM buttresses and 1.5 mm  at the FZ, IOR, arch, and SZ suture [72].   Stability requirements: For ideal stability, screws of  6 mm length with a minimum of two screws on either side  of fracture are essential. The only exception being the SZ  suture where one screw on either side of the fracture line  is adequate.   — One-point fixation [92] refers to fixation at either the  FZ or ZM suture. This has been found to be adequate  in resisting post-reduction in-stability in simple tripod  fractures while reducing hardware and_ surgical  exposure.    Comparative studies have shown that one-point  fixation at the ZM buttress has been found to more  advantageous due to many reasons: (1) absence of  external scarring; (2) ease of surgical access; (3) unlike  the FZ region, adequate soft tissue cover is present;  and there are no issues of plate palpability; (4) easier to  remove the plate, when needed; and most importantly  (5) ZM buttress is a better indicator of zygoma align-  ment than the FZ region due to the wider area of articu-  lation. However, FZ may be used in fractures with  comminuted ZM buttress.   Two-point fixation indicates fixation at ZM and FZ/  IOR [93, 94].   Three-point fixation/tripoding includes fixation at the  FZ, IOR, and the ZM. A recent meta-analysis indicates  that three-point fixation is the most effective in ensur-  ing absolute clinical stability against displacing forces  after reduction [94].   Four-point fixation/tetrapoding [95] involves fixation  at the FZ, IOR, arch, and the ZM. This may be indi-  cated in panfacial fractures requiring fixation of the  arch to restore the anteroposterior projection of the  face (case scenarios | and 2).   Five-point fixation/pentapoding [4] is used to manage  severely comminuted or dislocated ZMC fractures  wherein the SZ suture is also fixed, in addition to the  other four sites of fixation. The SZ fixation may be per-  formed either through a temporal or an intra-orbital  approach    Fig.56.55 Fixation of zygomatic arch fracture with microcompressive screws a, b, and c. (a) Preoperative CT showing diastasis at the zygomatic  root. (b) Intra-operative picture showing arch fixation with screw. (c) Postoperative CT showing adequate fracture reduction and screw fixation    Fig. 56.56 Types of fixation using miniplates. (a) One-point fixation at FZ suture; (b) one-point fixation at ZM buttress; (¢) two-point fixation;  (d) three-point fixation; (e) four-point fixation; and (f) five-point fixation (the 5th articulation (SPZ) of the right is unseen and hence is depicted on    — ZMC fractures requiring orbital reconstruction [59]:  irrespective of the type of fixation, when ZMC fracture  is associated with orbit, the orbital rims are fixed first.  This is important because it is safer and easier to gauge  the depth of orbital dissection from the restored infra-  orbital rim and also to facilitate floor reconstruction  [66] (case scenario 2). Also, the size of the orbital  defect is better assessed when the rims are aligned.   Though titanium miniplates are more commonly used  to fix ZMC fractures, substantial clinical success has been  obtained with use of bio-resorbable plates. They offer  comparable post-reduction stability along with the added  advantages of preventing thermal sensitivity and avoiding    the need for second surgery to remove plates. Limitations  associated with bio-resorbable plates are its technique  sensitivity and increased operating time.    The ORIF of arch fracture is indicated when the fragments  are unstable after closed reduction and in cases where re-  establishment of sagittal projection of face is needed.  Fixation may be performed by one of the three methods,  based on the fracture pattern (Fig. 56.57a, b, c): (1) a mini-  plate for an arch demonstrating a single fracture line  (Fig. 56.52b), (2) a spanning adaptation plate (Fig. 56.62b)    when the arch is multi-fragmented [98], and (3) a micro  screw for an outfractured root or sagittal fracture of the arch  [99] (Fig. 56.55). Kim et al. proposed plating on the superior  surface of the upper border as an alternate line of arch fixa-  tion which negated the drawbacks associated with the con-  ventional fixation [100] (Fig. 56.57).    Accurate reduction and fixation of ZMC fractures frequently  necessitates the use of multiple incisions on the midface  which deglove the entire periosteum-muscle-fat complex of  the midface and zygoma. Failure to re-approximate the dis-  sected tissues may lead to undesirable changes in the soft  tissue projection and form.    The various changes that may be a sequel to wide sub-  periosteal dissection of the midface include (1) cheek  ptosis, (2) descent of the lower eyelid skin and infra-  orbital hollowness, (3) loss of malar prominence due  to inferior displacement of the malar fat pad, and (4)  exaggeration of the nasolabial fold [101].    Over the years many authors have documented these  undesirable changes and proposed soft tissue resuspension  methods to minimize them. This can be achieved by various  methods (Fig. 56.58a): (1) re-approximating the incised peri-  osteum using absorbable sutures, (2) by suspending the peri-  osteum using heavy absorbable or nonabsorbable sutures to  a drill hole placed in a superiorly positioned bony landmark    Fig. 56.57 Different fixation options for zygomatic arch fractures. (a) Adaptation plate. (b) Miniplate. (¢) Compressive screw    Fig. 56.58 Soft tissue resuspension. (a) Graphical representation. (b) Resuspension of temporal soft tissues to deep temporal fascia (blue arrow)    such as the orbital rim [103], (3) resuspension of lateral  facial and temporal soft tissues to the deep temporal fascia in  the temporal region [104] (Fig. 56.58b), and (4) prophylactic  endoscopic midface lift [101].    Following reduction of ZMC fractures, with or without  fixation, the following measures are taken to maintain post-  surgical stability and prevent soft tissue complications  (Box 56.12):    e Soft diet: Patients managed with conservative methods  are advised soft diet for a period of 2 weeks.   e Frost suture: This temporary suspension suture is main-  tained for 3-5 days in any patient undergoing an inferior  eyelid approach for the prevention of ectropion.    Post-op sinus regimen [105]: A sinus regimen including  prophylactic antibiotics for sinus coverage and deconges-  tants is advocated by some authors.   Periodic assessment of vision [66]: Periodic ophthalmic  examination for the first 2 postoperative weeks is manda-  tory, in an awake patient. In an unconscious patient, it is  achieved by swinging flashlight test or VEP (visual  evoked potential).   Anti-edema measures: Head end elevation must be main-  tained to prevent facial edema.   Protection of eye with ophthalmic ointments.  Physiotherapy to prevent postoperative  trismus:  Postoperative trismus is a common phenomenon follow-  ing ORIF of ZMC fractures due to hematoma, reflex mus-  cle spasms, and fibrosis. Measures such as physiotherapy,  forced mouth opening using gag [107], and kinesiologic  tapes [108] may be used to improve mouth opening.   Eye movement exercises are encouraged to facilitate  resolution of edema and expedite restitution of move-  ments [66].    facial skeleton and injury to teeth. However, literature sup-  ports ORIF of zygoma fractures which are grossly dis-  placed or unstable after reduction. This is very important  in pediatric population to (1) correct the facial asymmetry  which may cause psychological impact, (2) restitute nor-  mal mouth opening to permit mastication, and (3) restitute  globe position and function to enable normal vision and  prevent development of phthisical eye or hypoplasia of  zygoma, in the future.    The preferred approaches include vestibular and lateral brow  with minimal soft tissue dissection. Literature suggests one-  point fixation at FZ region as adequate for pediatric ZMC  fractures because of the short lever arm forces between the  FZ and IOR [110]. But current studies have demonstrated  that two-point fixations provide adequate stability and are  associated with the least complication rates when compared  with one and three-point fixations. Similarly, fixation at the  zygomaticomaxillary buttress had the least complications  when compared against the fronto-zygomatic and infra-  orbital fixations [111]. In contrast, Defazio et al. proposed  that plating at the FZ and IOR may be done conveniently in  children below 6 years without any risk of damage to tooth  buds [112].    Fixation techniques prior to year 2000 advocated titanium  miniplates for pediatric midface. However they must be  removed after 2 months to prevent any growth disturbances,  plate migration, or burying of plate due to bone apposition.  Microplates and self-drilling screws are also reported to give  adequate stability and fixation in this age group without  compromising vital structures [110]. Alternatively, bio-  resorbable plates may be used which became popular after  year 2004 to negate the need for re-surgery for plate removal  [113]. Figure 56.59a—f shows a case of displaced zygoma  fracture in a 5-year-old boy managed by ORIF. The plates  were removed after 2 months.    Malunion of the zygoma may be a sequel to two clinical sce-  narios, (1) aneglected ZMC fracture which was never treated  and (2) an improperly treated fracture. The protocol for the  management of the malunited zygoma is based on the type of  deformity which may be either cosmetic or functional. The  protocol followed by the author is demonstrated in Fig. 56.60.   Deformities producing aesthetic concerns may again be  subdivided into those demonstrating facial asymmetry or  those showing altered globe positions.    Fig. 56.59 ZMC fracture management in a pediatric patient. (a)  Frontal view of patient with left-sided ZMC fracture. (b) Basal view  demonstrating loss of facial projection and enophthalmos of left side.  (c) Preoperative 3D CT image demonstrating en bloc displacement of  ZMC. (d) Preoperative coronal section demonstrating separation at FZ    suture and lateral displacement of the body of zygoma. (e) Postoperative  frontal view. (f) Postoperative basal view demonstrating restoration of  facial projection and enophthalmos correction. (g) Postoperative 3D  CT. (h) Post-operative coronal section    e The patients with asymmetries involving only the malar or  infra-orbital regions with no functional deficits can be  treated with onlay grafts which may either be autogenous  in nature (rib, iliac crest, calvarium) or alloplastic (Medpore,  PEEK (polyether ether ketone), etc.) (Fig. 56.61).   e Patients demonstrating gross facial asymmetry along with  orbital dystopia and/or anti-mongoloid slant of the palpe-  bral fissure may not be amenable to treatment with onlay  augmentations. In such cases, a conventional osteotomy  (re-fracture) and repositioning of the zygomatic complex  is advocated (case scenario 2).   ¢ When either of the deformities are associated with large  floor defects, they require concomitant orbital floor  reconstructions.    Functional deficits secondary to malunited ZMC frac-  tures essentially fall into three categories; Restricted mouth  opening, parasthesia and diplopia.    ¢ Restricted mouth opening due to retropositioned zygoma/  arch which either (1) forms a mechanical obstacle to man-  dibular translation or (2) fuses to the coronoid process of  the mandible (extra-articular ankylosis) (Fig. 56.62a, b).  The choice of treatment in these patients is dictated by the  presence or absence of fusion (bony/fibrous); ZMC oste-  otomy, and repositioning alone are indicated in the  absence of fusion, while presence of fusion mandates  additional coronoidectomy [8, 115].   e Paresthesia over the infra-orbital nerve (ION) distribu-  tion: The entrapment of the ION or constriction of the    infra-orbital foramen is not an uncommon finding. The  first line of management in these patients is to perform a  nerve release by an ostectomy around the infra-orbital  foramen or by repositioning of the ZMC when it is com-  pressing the nerve.   ¢ Diplopia: The major cause for diplopia in ZMC fractures  may either be gross displacement of the ZMC or mechan-  ical restriction due to entrapment of orbital soft tissues  (muscle, orbital septum, or fat) with resultant fibrosis or  adhesions. Correction in these instances is achieved only  by an osteotomy along with release of the entrapped tis-  sues. These patients may also require orbital floor recon-  structions if they present with floor defects that are large  (>2 cm? in area). Non-resolving diplopia may be sub-  jected to management with prism glasses and/or strabis-  mus surgery.    Bilateral fractures of the ZMC are a rare occurrence and  present more difficulty in achieving adequate reduction. In  contrast to unilateral fractures where the normal side is used  as a guide to achieve symmetry on the fractured side, bilat-  eral ZMC fractures are complex in management. Two options  exist: (1) reducing the less displaced or comminuted side  first and using it as a reference for the more displaced side  [116]. This may however result in compromised results, if  three- or four-point fixation is not achieved, and (2) meticu-  lous preoperative planning [43] by virtual surgical procedure    to achieve the ideal facial width and projection. This involves  a sequence of segmenting and virtually repositioning the  fracture fragments to the “best possible fit” position. Once  this is completed, the stents for intra-operative guidance can  be generated.    The incidence of postoperative complications increases with  certain risk factors such as severe displacement, presence of  sinus infection, and compound/comminuted ZMC fractures  [37].   The various complications specific to surgeries of the  ZMC may be categorized as intra-operative, immediate post-  operative, and delayed postoperative complications.    ¢ Intra-operative complications: Commonly encountered  intra-operative complications are bradycardia and bleeding.  Bradycardia due to  oculocardiac/trigemino-cardiac  reflex occurs typically during elevation of the ZMC [117].  Manipulation of zygoma stimulates the trigeminal nerve  which subsequently stimulates the vagus nerve, due to the  neuronal interconnections between them. Vagal stimula-  tion is cardioinhibitory and hence results in bradycardia  of varying degrees. This complication can be prevented  by identifying risk factors and administering prophylactic  vagolytic agents or minimizing nerve stimulation by  administering regional blocks. However, management of  bradycardia after its onset involves temporary cessation  of manipulation and or medical management with atro-  pine or epinephrine [64].    Fig. 56.62 Coronoidectomy for malunited ZMC fracture. (a) Pre-operative scan showing malunion of the right ZMC with fusion of the body of  zygoma and coronoid process, and (b) post-operative scan demonstrating reduction and fixation of the right zmc with ipsilateral    Brisk intra-op bleeding can occur due to the sudden rup-  ture of vessels (mainly infra-orbital artery) during  reduction.   ¢ Immediate postoperative complications: In the immedi-  ate postoperative phase, the adverse effects range from  maxillary sinusitis, meteorosensitivity [3] (discomfort  arising due to change in weather conditions) to infra-  orbital nerve paresthesia, diplopia, blindness, and SOF  syndrome. The incidence of postoperative infra-orbital  nerve paresthesia is higher with ZMC fractures which  demonstrate more rotation, displacement, and comminu-  tion [118]. Interestingly, recovery from post-trauma ION  paresthesia shows better prognosis with reduction and  fixation due to de-compression on the nerve. Blindness  following surgery may arise either due to direct injury to  optic nerve by impingement of fracture fragments or hem-  orrhage into the optic sheath/retro-bulbar hemorrhage  (Refer Fig. 56.16) producing nerve compression [119].   ¢ Delayed post-op complications commonly witnessed  include enophthalmos and hypophthalmos due to inade-  quate reduction or inadequate fixation. Oroantral fistula  [120], TMJ dysfunction [121], and ankylosis of zygoma  to coronoid process, referred to as Jacob’s disease [1,  122], are also recorded in literature.    Fractures of the ZMC are notorious for their sub-optimal  outcomes due to over or under reductions. This may be  attributed to difficulty in simultaneous visualization of its  multiple articulations without increasing surgical morbidity  due to additional exposures.   Technological advancements in the recent years have  added ease as well as predictability to the reduction and fixa-  tion of these fractures while minimizing surgical morbidity.  The most popular methods in contemporary surgical man-  agement are discussed below.    1. Intra-operative reduction and fixation templates [123]  This has been discussed earlier under the section for  preoperative planning.   2. Computer-assisted patient-specific implants (PSI) (42):  Another method for improving intra-operative accuracy  is the use of virtual surgery to plan for reduction of the  fracture and design patient-specific implants (PSI). These  PSI designs are then printed using a 3D printer which can  double up as intra-operative reduction guides also. Refer  to section 57.13.2 in Chap. 57 for additional information   3. Intra-operative navigation [124]: Intra-operative naviga-  tion is an excellent method for obtaining intra-operative  guidance for precise reduction. Refer to Chap. 41.  “Computer-assisted navigation surgery in oral and maxil-    lofacial surgery” for additional information. The margin  of error with use of intra-operative navigation is less than  1.2 mm with accurate restoration of facial symmetry. A  case of deformity secondary to ZMC fracture treated  using intra-operative navigation is illustrated in  Fig. 56.63.   4. Intra-operative imaging: Intra-operative imaging greatly  improves the accuracy of intra-operative fracture reduc-  tion. The various imaging modalities that are available  include ultrasound, conventional C-arm (videofluoros-  copy), and intra-operative CT. The quality of imaging  with videofluoroscopy is not accurate in reflecting the  complex anatomy of the cranio-facial skeleton. This  makes intra-operative CT a more accurate and reliable  tool. However, the associated radiation doses may be a  concern. This has been surmounted with the advent of the  intra-operative CBCT devices [125]. This device has the  significant advantages of portability, ease of use, increased  accuracy, and reduced radiation exposure.   5. Transbuccal Arch Fixation: A technique involving intra  oral reduction of zygomatic arch and its fixation by trans-  buccal instrumentation has been described by  Panneerselvam et al for fractures of the zygomatic arch  which are displaced at the zygomatico temporal articula-  tion. This technique minimises the potential morbidity  associated with the coronal approach which is commonly  used for ORIF of zygomatic arch [126].    The ZMC fracture is one of the most complex fractures to  reduce and fix, because of its propensity to undergo displace-  ments in all three planes of orientation, along its five articu-  lations. Accurate reduction is challenging due to the difficulty  in intra-operative assessment of reduction, inability to pre-  dict the rotation of the zygoma during reduction, and com-  plexity involved in concomitant orbital fractures.    The surgical objectives must include (1) choice of inci-  sions which provide maximal exposure with minimal  morbidity, (2) increase in number of fixation points  with increase in severity of fracture displacement, (3)  achieving three-dimensional stability of ZMC com-  plex and minimizing post-reduction complications,  and (4) resuspension of overlying soft tissues to pre-  vent sagging.    Preoperative planning and intra-operative imaging play a  great role in improving accuracy of fracture reduction while  minimizing surgical exposure and __ post-reduction  complications.    Intra-operative navigation for ZMC fracture. Multiplanar sections demonstrating superimposition of patient CT (white) and surgical.  Plan (pink) with use of intra-operative navigation to verify position during surgery (blue pointer)    Acknowledgment The authors would like to acknowledge the efforts  of the postgraduate trainees Dr. Vijitha and Dr. Logitha Sri towards the  illustrations.    ¢ Medial displacement with reduction of the transverse  dimension of the face    Surgical plan: Reduction of ZMC fracture with four-  point fixation  Surgical procedure:   ¢ Four-point fixation of fracture was performed at FZ, IOR,  ZM, and SZ (Fig. ) regions with miniplates   CT demonstrating optimal reduction of fractured ZMC  and arch. The successful surgical outcome may be appreci-  ated by the approximation and fixation at the SZ suture,  which is the most reliable indicator of accurate ZMC  reduction.    Fig. 56.64 Case scenario |. (a) Preoperative 3D CT-frontal view dem-  onstrating fractures. (b) Postoperative 3D CT-frontal view demonstrat-  ing fixation. (c) Preoperative 3D CT-basal view demonstrating arch    Case Scenario 2: Fracture of left ZMC and  orbital floor (Fig. 56.65 a—h)    Patient: 27-Year-Old Male with History of RTA  and delayed presentation after 2 months  Preoperative CT findings (Fig. 56.65a, b):    ¢ En bloc fracture of the left ZMC with diastasis at the  left infra-orbital rim, zygomatic arch, and FZ and SZ  sutures.   ¢ The fracture shows posterior, inferior, and lateral dis-  placement and comminution at the infra-orbital rim,  zygomaticomaxillary buttress, and the arch.   ¢ The CT also demonstrates a concomitant left orbital floor  fracture with resultant enophthalmos and hypo-ophthal-  mos (Fig. 56.65g).    fracture. (d) Postoperative 3D CT-basal view demonstrating arch reduc-  tion. (e) Postoperative 3D CT demonstrating fixation at SZ suture. (f)  Intra-operative fixation at SZ suture    e Virtual surgical planning to generate a mirrored STL  model for pre-contouring of implants (Fig. 56.65c, d)   e Surgical exposure of the fracture through a transconjunc-  tival (infra-orbital rim and floor), upper lid blepharoplasty  (FZ and SZ sutures), vestibular for the ZM buttress, and  preauricular approaches for the zygomatic arch.   ¢ Mobilization of the malunited ZMC after osteotomy and  ORIF with pre-contoured implants   e Fixation of the fracture performed at the FZ, infra-orbital  rim, and the zygomatic arch regions   e Orbital exploration and reconstruction with pre-contoured  left-sided anatomical titanium orbital implant   The postoperative CT demonstrates optimal reduction  and fixation of the left ZMC with reconstruction of the left  orbital floor defect with titanium implant.    Fig.56.65 Case scenario 2. (a) Preoperative 3D CT-frontal view dem- view demonstrating fixation. 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Open Access This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.  org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropri-  ate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.   The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in  a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.   Orbital fractures are unique among cranio-maxillofacial  (CMF) fractures. They have functional, cosmetic, and psy-  chological implications. Most importantly they are among  the few true emergencies in the realm of CMF trauma.  Management of orbital fractures poses a challenge to every  surgeon because of its complex anatomy, relationship to vital  structures such as the globe and the brain, and its direct influ-  ence on the most precious of senses, Vision.   The orbit is a small bony cone filled with numerous vital  and delicate structures, which require absolute precaution  while handling and immense precision in its reconstruction.  The principles of managing orbital trauma differ signifi-  cantly from rest of the CMF fractures, which mandate a thor-  ough understanding of its morphology and biodynamics.  Choosing the appropriate indication for intervention and  management protocol is critical in achieving the desired sur-    Electronic Supplementary Material The online version of this  chapter (https://doi.org/10.1007/978-98 1-15-1346-6_57) contains  supplementary material, which is available to authorized users.    A. Parameswaran   Department of Oral and Maxillofacial Surgery, Meenakshiammal  Dental College and Hospital, Chennai, India    Department of Orbit, Oculoplasty, Reconstructive and Aesthetic  Surgery, Shankara Nethralaya, Chennai, India    M. Marimuthu  Department of Oral and Maxillofacial Surgery, Saveetha Dental  College and Hospital, Chennai, India    S. Panwar  Department of Oral and Maxillofacial Surgery, Meenakshiammal  Dental College and Hospital, Chennai, India    B. Hammer  CFC Hirslanden Kopf Zentrum, Aarau, Switzerland  e-mail: Beat.Hammer @hirslanden.ch    © The Association of Oral and Maxillofacial Surgeons of India 2021    gical outcome. This chapter aims to answer the questions of  the When, Why, and How of managing orbital trauma.    The orbits are bilateral bony cavities which house the globes.  Each orbit is made up of seven bones: the maxilla, frontal  bone, zygomatic, sphenoid, ethmoid, lacrimal, and the pala-  tine bones (Fig. 57.1). The orbital cavity is a pyramidal struc-  ture with a quadrilateral base anteriorly, forming the orbital  aperture, and the apex posteriorly which ends at the optic  foramen. The apex is superomedially placed, while the base  is directed anterior and lateral. The orbit encases two fis-  sures: (1) the inferior orbital fissure also called the sphenozy-  gomatic fissure and (2) the superior orbital fissure otherwise  called as the inter-sphenoidal fissure (Fig. 57.2). The major  structures within the orbit are provided in Box 57.1.    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1-15-1346-6_57    Fig. 57.2 Structures passing  through the superior and  inferior orbital fissures    The orbits have an average height of 35 mm and a medio-  lateral width of 40 mm [1-3]. The intra-orbital volume of an  adult is approximately 30 cc, while the volume of the globe  is 7 cc [4]. Generally, the orbital and globe volumes are bilat-  erally symmetrical at any stage of growth. The medial walls  are parallel to each other and around 45-50 mm in length,  while the lateral walls are around 90° to each other and  40-45 mm long (Fig. 57.3).   The orbital skeleton may essentially be divided into walls  and rims. These include the orbital roof, floor, and medial  and lateral walls. The rims include the inferior, superior,  medial, and lateral orbital rims. A brief description of the  structure of the orbital cavity is provided below.    The roof (Fig. 57.4a) is formed by a concave broad plate of the  frontal bone which delineates the orbital contents from the cra-  nial cavity. The posterior portion of the roof has a small contribu-  tion from the lesser wing of the sphenoid. The anterolateral  portion has a shallow depression called the lacrimal fossa, while  5 mm behind the medial aspect of the supraorbital rim is the  trochlear fossa which has the cartilaginous pulley of the superior  oblique muscle. The roof is triangular in shape and ends in optic  foramen, which is the entry of the optic nerve into the orbit.   In older patients there may be spots of resorption in the  orbital roof which may cause the dura to adhere to the peri-  orbita of the roof. The junction of the medial wall and the  roof has a suture line which lies in close proximity to the  cribriform of the ethmoid and is prone for fragmentation.  This may be a major concern for CSF leak into the orbits or  the nose or at times both.    Fig. 57.3 Diagrammatic representation of the various measurements  of the orbit and the globe    The roof is separated from the lateral orbital wall by the  superior orbital fissure which serves as a passage of entry for  the cranial nerves III, IV, V1, and VI into the orbit. The other  structure coursing through the fissure is the ophthalmic vein.  On the anterior aspect of the roof, at the junction between the  medial 1/3rd and the lateral 2/3rd of the supraorbital rim is  the supraorbital foramen which transmits the supraorbital  neurovascular bundle [1-—3, 5].   The medial wall (Fig. 57.4c) is quadrangular in shape and  is constituted by the ethmoid bone in the center. The antero-  superior aspect is formed by the frontal bone, while the antero-  inferior part is formed by the lacrimal bone. The sphenoid  bone forms the posterior part of the medial wall. The infra-  orbital rim continues along the anterior aspect of the medial  wall forming the anterior lacrimal crest which is a part of the  frontal process of the maxilla, while the superomedial aspect  of the supraorbital rim continues inferiorly as the posterior lac-  rimal crest which is formed by the lacrimal bone. Between  these crests lie the fossa which houses the lacrimal sac. This is  of importance during access planning for surgery of the medial  wall and the anteromedial aspect of the infra-orbital rim.   The anterior and posterior ethmoidal foramen are located  along the fronto-ethmoidal suture which signifies the height  of the cribriform plate. The anterior ethmoidal foramen  which transmits the anterior ethmoidal artery and nerve lies  approximately 22—25 mm behind the medial orbital rim  while the posterior ethmoidal foramen which transmits the  posterior ethmoidal artery and the spheno-ethmoidal nerve is  present about 12 mm posterior [6]. The optic foramen is in  continuation of the medial wall and is approximately placed  45-50 mm behind the medial rim. The safe distances the sur-    Fig. 57.4 (a) Roof, (b) lateral wall, and (c) medial wall of the orbit    geon needs to remember are 24 mm for the anterior eth-  moidal artery, with an additional 12 mm for the posterior  ethmoidal vessel and a further 6 mm as the limit to stay away  from the optic foramen making it 24-/2-6, an easy formula  to remember. One important structure which may be involved  in medial wall trauma is the medial rectus muscle which can  get entrapped causing ocular motility disturbances.    The lateral wall (Fig. 57.4b) is the thickest wall and is  made primarily by the orbital surface of the zygomatic bone  and the greater wing of the sphenoid. A small bony projec-  tion seen on the lateral wall is the Whitnall’s tubercle which  lies 11 mm below the fronto-zygomatic suture and 4 mm  behind the rim (Fig. 57.7).   2. The lateral horn of the levator aponeurosis  3. The ligaments of the lateral rectus muscle  4. The lateral palpebral ligament    A small groove may be seen at the anterior end of the  inferior orbital fissure which transmits the zygomatico-facial  and zygomatico-temporal vessels. These course through the  zygoma and exit through independent foramina to supply the  face and the temporal regions.   The floor (Fig. 57.5a, b) follows a gentle slope from its  medial to lateral side. The highest point lies in the postero-  medial aspect of the floor forming a bulge called the  “Hammer’s key area” [7] (Fig. 57.5a), which influences the  position of the globe in the anteroposterior axis. In the sagit-  tal view, the floor follows a “lazy S” shape with the anterior  part concave and the posterior convex. The reconstruction of  this convexity is important to maintain the anterior position  of the globe (Fig. 57.5b). The floor is separated from the lat-  eral wall by the inferior orbital fissure. The fissure communi-  cates with the pterygopalatine fossa extra-orbitally. The  maxillary division of the V nerve and its branches, the infra-  orbital artery, and branches of the sphenopalatine ganglion  are transmitted through the posteromedial aspect of the fis-  sure, while the inferior ophthalmic veins pass through the  lateral aspect to communicate with the pterygoid plexus. The  floor is formed by the zygomatic bone and the maxilla with a  small contribution from the orbital process of the palatine  bone in the posteromedial aspect. A rough area at the antero-  medial angle of the floor behind the infra orbital rim forms  the attachment of the inferior oblique muscle. The infra-  orbital groove originates from the inferior orbital fissure and  transmits the infra-orbital neurovascular bundle.   The rims are superior, inferior, medial, and lateral. Three  major bones—the maxilla, zygomatic bone, and frontal  bone—make up the rims of the orbit. The width of the rims  is greater than its height making it into a rectangular form.  The presence of the maxillary sinus and the insertion of the  inferior oblique muscle make the infra-orbital rim more  prone for fracture and comminution.    e the muscles associated with the lids  e and the muscles associated with the globe.    1. The orbicularis oculi which has a palpebral portion (upper  and lower eyelids), the intervening orbital septum, and  the inner layer connecting the tarsus   2. The levator palpebrae superioris which is the elevator of  the upper eyelid  The levator palpebrae superioris along with the four recti,  and the two obliques form the seven extraocular muscles  of the human eye.    Fig.57.6 Diagram of right eye demonstrating (a) the extraocular mus-  cles and (b) the movements they cause. (ce) The fascial sheath. (SR -  Superior Rectus, /R - Inferior Rectus, MR - Medial Rectus, LR - Lateral    The origin of the superior rectus is from the common ten-  dinous ring superolateral to the optic canal, and its insertion  is into the upper part of the sclera. Its function is to produce  elevation of the eye and to move the cornea upward and  medially helping in adduction and medial rotation.   The origin of the medial rectus is from the medial aspect  of the tendinous ring and inserts into the medial surface of  the sclera. The medial rectus helps in moving the eye medi-  ally (adduction), and bilateral action of the medial rectus  helps in medial convergence of both the corneas. A suspen-  sory attachment to the lacrimal crest is also seen on the  medial orbital wall where it blends with the medial canthus  and the check ligament (Fig. 57.6c) [2, 3, 6, 8]. The origin  of the lateral rectus is from the lateral part of the common  tendinous ring, and it inserts into the lateral surface of the  sclera. Its primary function is to move the eye laterally  (abduction).The inferior rectus arises from the common ten-  dinous ring, below the optic canal, and inserts into sclera  below the cornea. It is responsible for depression and lateral  rotation of the eye.   The inferior rectus followed by the medial rectus are the most  common muscles to be entrapped secondary to orbital trauma  and may need to be explored and released surgically as indicated.  Delayed release of the recti may cause significant necrosis and  fibrosis of the muscles hampering return to normal function.   The superior oblique arises superomedial to the optic  canal. It has a pulley action at the trochlea on the anterome-  dial aspect of the orbital roof and inserts into the sclera  behind the equator of the globe. The contraction of the mus-  cle produces depression of the cornea and movement of the  eye laterally with medial rotation (intorsion).   The inferior oblique muscle arises from the orbital sur-  face of the maxilla lateral to the nasolacrimal groove and  inserts into the lateral part of the sclera behind the equator  between the inferior and lateral recti muscle. It produces    Rectus, SO - Superior Oblique, /O - Inferior Oblique, CL(MR) - Check  Ligament of Medial Rectus, CL(LR) - Check Ligament of Lateral  Rectus, SL - Suspensory Ligament    elevation of the cornea and helps in moving the eye laterally  with lateral rotation (extorsion).    The different movements of the eye are enumerated in Box  57.2. These are facilitated by the extraocular muscles  described above and are contained by the check ligaments.  The inferior oblique and inferior rectus muscles which  course the floor of the orbit serve as the inferior check liga-  ments. The fascia of the levator palpebrae superioris, which  is anchored to the Whitnall’s tubercle laterally and the troch-  lea medially, acts as the superior check ligament [8].   The contraction of the orbicularis oculi innervated by the  facial nerve dictates the closure of the upper eyelid. The move-  ments of the globe within the orbit are however dictated by the  synchronous movements of the extraocular muscles of the orbit.  The oculomotor nerve innervates all the extraocular muscles  other than the lateral rectus which is supplied by the abducent  nerve and the superior oblique supplied by the trochlear nerve.  Reflex closure of the eyelids occurs via the sympathetic pathways  traveling to the smooth muscles of the upper and lower eyelids.    The supporting framework for the eyelid is formed by a  dense fibrous tissue called the orbital septum which con-  denses at the lids as the tarsal plates. The orbital septum  which separates the orbital and lid contents attaches to the  bone and becomes the periorbita inside the orbit and perios-  teum outside the orbit. The septum of the lower eyelid  attaches to the orbital rims, while the septum of the upper  eyelid is attached intra-orbitally behind the equator of the  globe. The tarsal plates add rigidity to the lids and also serve  attachments of multiple muscles and membranes [1, 3].    The conjunctiva is the transparent mucous membrane that  covers the front surface of the globe and the inner surface of  the eyelids.    1. The bulbar conjunctiva that covers the anterior part of the  sclera (the “white” of the eye)    2. The palpebral conjunctiva otherwise known as tarsal con-  junctiva which covers the inner aspect of the eyelids    The fascial sheath of the eyeball is called the Tenon’s cap-  sule [8]. It extends from the optic foramen to the sclerocor-  neal junction enveloping the eyeball on the inferior aspect.  It attaches to the sclera on the anterior and posterior sur-  faces of the eyeball and becomes continuous with the fas-  cia of the muscles posteriorly and around the inferior  oblique muscle. The fascial sheath of all muscles blend  together and form a continuous fascial band called the sus-  pensory ligament of the eye that provides support for the  eyeball [8, 9].    The orbital fat is present both intra- and extra-conally. They  cushion the globe and muscles of the orbit. The extra-conal  fat determines and influences the position of the globe. This  may be altered either due to herniation or atrophy secondary  to fractures of the orbit resulting in enophthalmos.    (a) Pure (blow-in or blowout fractures)—fracture of the  internal walls with intact rims   (b) Impure (complex with involvement of one or more  rims)—associated fractures of the rims    Hammer [7] described four classes of orbital fractures  based on their occurrence with other fractures of the face  (Fig. 57.9):    (a) Type I: Orbito-zygomatic fractures—These involve the  fractures of the walls of the orbit along with the zygo-  matic complex.   (b) Type II: Internal orbital fractures—These involve iso-  lated fractures of any of the walls, roof, and floor.   (c) Type III: Naso-orbito-ethmoid-type fractures—These  involve fractures of the naso-orbito-ethmoid complex  which involve the orbit.   (d) Type IV: Complex fractures of the face—This type  involve fractures of the orbit with concomitant fractures  of the face other than the ones mentioned above [7].    Smith and Converse in 1960 recognized the phenomenon of  blowout fractures (Fig. 57.10a). These fractures may involve  entrapment or herniation of periorbital tissues resulting in  restricted eye movements and/or enophthalmos due to  reduction in the volume of intra-orbital contents [3, 11].    Fig. 57.8 CT scans showing Pure (a and c) and impure (b and d) blowout fractures of the orbit    “Blow-in” type of orbital fractures was described by (Fig. 57.10b). Such types of fractures are usually accompa-  Dingman and Natvig [3, 12] in 1964 wherein the intra-orbital nied with proptosis on the affected side [13].  space is reduced by an internally displaced bony fragment    Fig.57.9 CT scan images showing types of orbital fractures: (a) orbito-zygomatic, (b) internal orbital, (c) naso-orbito-ethmoid type, and (d) orbit  with complex facial fractures    Fig. 57.10 CT scans  demonstrating a blowout of  the medial orbital wall and  floor (a) and a blow-in  fracture of the orbital roof (b)    One of the first mechanisms of orbital wall fractures was  suggested by Pfeiffer [14] in 1943, called globe-to-wall  theory or hydraulic theory (Fig. 57.11a), wherein poste-  rior displacement of the globe after sustaining a direct hit    was propounded to transmit force along the walls result-  ing in fracture of the thinner walls. There are two more  widely accepted mechanisms of orbital wall fractures,  namely, the:    (i) Retropulsion theory (Fig. 57.11b)  (ii) Buckling mechanism [15] (Fig. 57.11c)    Fig.57.11 Diagrammatic representation of (a) hydraulic theory, (b) retropulsion theory, and (c) buckling mechanism    First proposed by King [16] in 1944, retropulsion theory  suggests that sudden increase in intra-orbital pressure caused  by direct hit from a large object creates stresses along the  orbital walls resulting in fractures at the areas of least thick-  ness. The buckling theory or transmission theory explains  the injury through a ripple effect created in the floor. The  ripple thus created causes compression in an anteroposterior  direction and resultant fracture at the posteromedial part of  the orbital floor commonly [17, 18].    After initial stabilization of the patient, a thorough facial  examination is performed in a way similar to any facial frac-  ture. Special consideration is given to a detailed ophthalmic  evaluation followed by eliciting signs and symptoms signifi-  cant for periorbital trauma which are discussed below. The  frontal area and supraorbital rim are examined first, with a  logical progression downward, including the lateral and  infra-orbital rims, although extensive edema in this area may  obscure any steps making the palpatory examination difficult  [3, 7, 19-22].   1. Visual acuity: Visual acuity test for each eye is recorded  using a Snellen chart (Fig. 57.12a) and includes ability to  read letters, count fingers, perceive hand movements, and    light perception. If visual acuity is extremely poor and  recording of a chart test fails, the patient is subjected to a  finger counting test or at times even assessed for primary  light perception alone.   Glaucoma, previous history of surgery, and/or injury to  ocular system may also account for anisocoria or irregu-  lar pupils. Peaked or irregular pupils may also be indica-  tive of perforation of the globe. The swinging flashlight  test is performed for relative afferent pupillary defect  (RAPD) (Fig. 57.12b).    screened for all the six cardinal gazes (Fig. 57.12c). First  checked binocularly for versions of both sides and then  checked monocular for ductions. A thorough heterotropia  check is also performed. Diplopia and restrictions in  gazes are noted. Clinically, a forced duction test under  topical anesthesia is done to elicit mechanical impedi-  ment to movement of the globe. This may also be per-  formed under general anesthesia intraoperatively  (Figs. 56.21, 57.13). A Hess chart examination is a part of  the orthoptic assessment protocol for evaluation of ocular  motility.    evaluate intraocular pressure either in a clinic setting  using a Goldmann applanation method or outside using  a mobile/portable device. This examination is skipped if  there is a suspicion of ruptured globe. The normal IOC    Fig. 57.12 Picture showing (a) the Snellen chart, (b) swinging flash light test, and (c) the six cardinal signs of gazes    Fig. 57.13 Demonstration of the method of performing intraoperative  forced duction test (a) by grasping the limbus (sclero-corneal junction)  and (b) by grasping the inferior rectus muslce    is a range between 10 and 21 mmHg with the mean  being around 15 mmHg. Low IOP may be suggestive of  a ruptured globe or detached retina, while increased IOP  may indicate hyphema, glaucoma, or an orbital com-  partment syndrome like “retrobulbar hemorrhage.” A  pressure of more than 30 mmHg is an ophthalmological  emergency.   5. Visual fields: Visual fields for each eye are checked by  asking the patient to determine movements at the periph-  ery of the examiner’s own visual field, while at a distance  of about 2 ft from each other. Loss of field may be sug-  gestive of compressive or ischemic injuries to the optic  nerve with or without damage to the visual pathway.  Goldmann visual field test can also be employed to objec-  tively chart binocular visual field loss wherein patient is  asked to look at a center of the chart and is required to  track a point source of light.    6. External examination/periorbital screening: A thorough  clinical evaluation is performed to note down all clinical  features detailed below. Orbital trauma is generally  associated with possible adnexal injuries which also need  to be assessed for intervention and management.   7. Slit-lamp examination: A formal slit lamp test is per-  formed if it may be allowed. This provides information  about the lids, lashes, lacrimal system, conjunctiva,  sclera, anterior chamber, iris, the lens, and the anterior  vitreous.   8. Fundoscopic examination: A fundoscopic examination is  performed to assess the retina, optic nerve head, and the  vessels. This is done by the use of an ophthalmoscope. It  also provides information about presence of intraocular  hemorrhages and foreign bodies.   9. Globe position: An important feature in examination of  orbital trauma from a cranio-maxillofacial perspective  includes the examination of globe positions. This is per-  formed both clinically and by using an exophthalmome-  ter. The Hertel’s exophthalmometer is used in common  settings for the evaluation of proptosis or enophthalmos.  In case of injuries involving the lateral face, like a frac-  ture of the ZMC, the Naugle’s exophthalmometer is used.    A good evaluation of the skeletal and soft tissue components of  the orbit as well its associated adnexa (eyelids, lacrimal appara-  tus, etc.) is mandated. The common clinical features that are  presented with in orbital trauma are provided in Box 57.4.    Fig. 57.14 Clinical pictures demonstrating (a) edema of the left periorbital region, (b) left-sided periorbital ecchymosis and subconjunctival  hemorrhage, and (c) soft tissue injury of the left eyelid and supraorbital region    Clinical signs and symptoms that are more exclusive to  orbital trauma are discussed further in more detail.  57.6.2.1_ Enophthalmos/Hypophthalmos  (Fig. 57.15a, b)  Any change in the orbital volume directly impacts the posi-  tion of the globe and its anteroposterior projection and  supero-inferior position [24]. Clinically enophthalmos can be  detected by an exaggerated suprapalpebral fold and reduced  projection on viewing from an inferior view or worm’s view.  Hertel’s or Naugle’s exophthalmometer can also be used to  quantify and measure the discrepancy. Other causes of enoph-  thalmos implicated are traumatic atrophy of intra-orbital fat,  infections causing cicatricial contraction of retrobulbar tis-  sues, and dislocation of trochlear attachment of superior  oblique muscle due to trauma [25, 26]. Hypophthalmos is  noted as a change in the horizontal pupillary levels.    57.6.2.2_ Retrobulbar Hemorrhage (Fig. 57.16)  Retrobulbar hemorrhage is a vision threatening emergency  which occurs due to accumulation of blood in the retrobulbar    space. This causes increased intra-orbital pressure resulting  in compression or stretching of the optic nerve and reduced  perfusion to the eye. Orbital trauma especially blunt injury  may be associated with retrobulbar hemorrhage which war-  rants immediate attention. However this may also occur as a  complication following surgery to the orbit or pathologies  like an aneurysm. Acute post-septal hemorrhage limited  anteriorly by the orbital septum and posteriorly by bone may  cause permanent loss of vision by creating a compartment  syndrome [27]. It presents as reduced ocular motility, ele-  vated intraocular pressure, proptosis, and diminishing vision.  In unconscious patients, pupillary assessment, increased  pressure, and presence of relative afferent pupillary defect or  RAPD are usually diagnostic.   Due to its close topographical location to the orbital com-  plex, nasolacrimal system especially the duct may be  involved in traumatic injuries to the orbit. Injury to the  canaliculi or the nasolacrimal ducts in naso-orbito-eth-  moidal injuries may present as epiphora [28]. Patency of    Fig. 57.15 Clinical photograph of a patient with both (a) hypophthalmos and (b) enophthalmos of the right globe    Fig. 57.16 (a) Axial, (b) coronal, and (c) sagittal section CT scan images demonstrating left-sided retrobulbar hemorrhage    the naso-lacrimal duct and sac can be verified by the Jones  tests | and 2 or by a simple lacrimal probing test with inser-  tion of a Crawford silicone intubation tubes though the  canaliculi and visualization of the same at the distal end of  the disruption. ROPLAS test or regurgitation on pressure  over lacrimal sac may be performed clinically to elicit post-  traumatic blockage of the nasolacrimal duct (Fig. 57.17c).  Confirmation however is obtained with a CT dacryocysto-  gram or CT-DCG (Fig. 57.17a, b). Reconstruction of the  lacrimal drainage system is achieved by simple intubations  or a formal dacryocystorhinostomy as indicated by the clin-  ical scenario.   First described by Dagnini and Aschner in 1908, oculocar-  diac reflex is bradycardia on manual compression of the  eyes. The most common traumatic etiology is the incarcera-  tion of inferior rectus muscle in trap-door fractures of the  orbital floor [29, 30]. Other causes that may present with  oculocardiac reflex are retrobulbar hemorrhage, white-eyed  blowout fractures and orbital surgery.   (Box 57.5)  Post-traumatic superior orbital fissure syndrome may be  attributed to pressure exerted on the contents of the superior  orbital fissure due to hemorrhage or impingement by frac-  tured fragments.    Superior orbital fissure syndrome was first described  by Hirschfield in 1858 [31, 32] and symptoms include:    (i) Ophthalmoplegia due to involvement of III,  IV, and VI cranial nerves.   (ii) Paresthesia over the forehead due to involvement  frontal nerve of first division of trigeminal nerve.   (111) Ptosis due to impeded action of levator palpe-  brae superioris and Muller’s muscle.   (iv) Pupillary dilatation due to paresis of circular  sphincter muscle and unrestricted action of  dilator pupillae.   (v) Impairment of direct pupillary reflex due to  blocked ipsilateral efferent arc, whereas con-  sensual reflex is preserved due to intact ipsilat-  eral efferent and contralateral efferent arcs.    Fig. 57.17 (a) Sagittal  section CT DCG  demonstrating patent NLD  with draining dye and (b)  blocked NLD with no  drainage of the dye. (c)  Clinical photograph of patient  with left-sided NOE fracture  demonstrating regurgitation  of contents due to blocked left  naso-lacrimal duct ROPLAS  positive    Fig. 57.18 Clinical pictures and CT scans of patient with orbital apex  syndrome. (a) Clinical picture demonstrating left-sided orbito-zygo-  matic trauma with clinically evident ptosis, (b) 3D CT demonstrating  comminuted zygomatico-orbital fracture with medial displacement of  the greater wing of sphenoid, (c) clinical picture of patient 2 weeks  post-surgery with resolution of ptosis, (d) post-operative 3D CT show-    (vi) Impaired accommodation is because of  impaired parasympathetic pathway to the  ciliary ganglion.   Loss of corneal reflex due to lack of trans-  mission via the nasociliary branch of oph-  thalmic nerve.   Proptosis either due to presence of hemor-  rhage or paresis and laxity of extraocular mus-  cles which normally aid in globe retraction.    ing ORIF, (e) pre-operative axial CT demonstrating total compression  of the left optic canal (yellow arrow), (f) pre-operative coronal CT dem-  onstrating compression of the left superior orbital fissure (yellow  arrow), (g) post-operative CT showing decompressed left optic canal  (yellow arrow) and (h) post-operative coronal CT showing decompresi-  son of the left superior orbital fissure (yellow arrow)    Management may be conservative or exploratory surgery  of the orbit including surgical decompression [33].   (Box 57.5)  In severe orbital trauma, optic nerve may also be implicated  due its close proximity to the superior orbital fissure [31,  34]. The term orbital apex syndrome was first coined by  Kjaer in 1945 [35], and the symptoms include all features    Fig. 57.19 (a, b) Axial CT  scan of patient with direct  traumatic optic neuropathy  demonstrating a skull base  fracture and bony spicule at  the entry of the optic nerve  into the canal    of superior orbital fissure syndrome along with partial or  loss of vision.   TON may be defined as an acute injury to the optic nerve with   impairment of visual function. It may occur as a result of:   (i) Direct trauma to the optic nerve (Fig. 57.19) (physical  damage or nerve sheath compression due to compart-  ment syndromes)   (ii) An indirect insult due to diffuse axonal damage second-  ary to conduction of forces from blunt head trauma  The occurrence may be unilateral or bilateral.    Management of TON is handled under the section of  orbital emergencies.    Box 57.5 Comparison of Clinical Features of Traumatic  Optic Neuropathy, Superior Orbital Fissure, and Orbital  Apex Syndromes    dard” in orbital trauma. The scans are usually ordered in  fine cuts of 0.5 mm and taken in all the three planes. The  coronal and the sagittal scans are important in the diagnosis    Fig. 57.20 CT scans showing (a) axial section with fracture of the medial wall of the right orbit, (b) coronal section showing fractures of the  medial wall and floor, and (c) sagittal section showing fracture of the floor with fibrosis of the inferior rectus to the posterior ledge (yellow arrow)    Fig. 57.21 MRI (a) coronal  and (b) sagittal sections,  demonstrating entrapment of  the medial rectus (yellow  arrows) and medial  displacement of the optic  nerve (left orbit)    of fractures of the floor and the roof, while the axial scans 57.7 Approaches to the Orbit   to study the optic canal integrity. Box 57.6 Surgical Approaches to the Orbit  Indications for an MRI (Fig. 57.21a, b) scan are limited to   and to assessing damage to the optic nerve. It is also used to   identify intra-orbital herniation of brain in the case of blow- * Transconjunctival    1. Lynch  2. Extended glabellar approach  (a). Lateral transcutaneous approaches  (i) Lateral brow incision  (ii) The upper lid blepharoplasty and the sub  brow approaches  (b). Lower eyelid approaches (Also refer Figs. 56.44,  56.45)  (i) Sub-ciliary  (ii) Sub-tarsal  (iii) Infra-orbital (Video 57.1)   This incision described by Lynch [36] in 1921 is a  semilunar-shaped incision (Fig. 57.22a) placed between  the nasal dorsum and the medial canthal ligament that pro-  vides direct access to the canthal apparatus and the medial  orbital rim and wall. The major drawbacks of this particu-  lar incision are chances of developing a web and hence an  unsightly scar. There may also be risk of damage to the  medial canthal tendon and the lacrimal apparatus that is  present infero-laterally. Recent modifications of the Lynch  incision have accommodated options to reduce the scar-  ring by the use of “Z” plasties (Fig. 57.22b, c) and other  esthetic incision designs.    Fig. 57.23 Diagram and intraoperative picture showing extended glabellar approach to the medial orbit   The extended glabellar incision or a horizontal “Y” approach  involves a small Y-shaped incision with the fork extending  over the upper and lower lid crease with the long arm across  the nasal dorsum over the glabellar region. This approach  provides excellent access to the medial canthal tendon appa-  ratus and also provides enough room for medial orbital wall  exploration cephalad to the tendon.    The trans-caruncular route provides excellent exposure to the  medial orbit without causing any esthetic concern. The car-  uncle is a papular structure seen medial to the plica semiluna-  ris which is a fold of conjunctiva in medial canthal region. An  avascular plane is located deep to the caruncle between the  medial orbital septum and the Horner’s muscle which on dis-  section exposes the medial wall of the orbit (Fig. 57.24a) [37].    Fig.57.24 (a) Diagram and (b) intraoperative pictures showing marking for trans-caruncular approach to the medial orbit and (c) exposure of the  medial orbital wall. (Courtesy: Dept of Orbit & Oculoplasty, Shankara Nethralaya, Chennai)    After placing retraction sutures on upper and lower eye-  lids, gentle medial traction is applied over the skin of the  nasal dorsum, and incision is placed lateral to the caruncle,  while avoiding injury to the lacrimal puncta or canaliculi  (Fig. 57.24b). The length of the incision is between 1.5 and  2.5 cm. Dissection through the fibers of the Muller’s muscle  exposes the medial wall just posterior to the posterior lacri-  mal crest (Fig. 57.24c). For additional exposure of associated  orbital floor fractures, a C-shaped approach can be used  including a transconjunctival incision with or without lateral  canthotomy and inferior cantholysis in conjunction with the  trans-caruncular approach.   As the lateral transcutaneous and lower lid approaches  also find use in the management of fractures of the zygo-  matic complex fractures, they are discussed in detail in chap-  ter on zygomatic complex fractures.    The infra-orbital rim and orbital floor defects can be accessed  through a transconjunctival incision (Video 57.2).  Its advantages include:  (i) Excellent cosmesis   (iii) Extensive access up to 270° including the floor and  medial and lateral walls, with the modifications to the  conventional approach    A historical perspective of the description of the transcon-  junctival approach and its evolution into the most favored  approach for access to the floor and medial wall of the orbit  along with the infra-orbital rim is provided in Box 57.7.   The incision is marked 2—3 mm posterior to the tarsal plate  along the mediolateral length of the lower palpebral conjunc-  tiva. Dissection is performed along the subconjunctival plane  and is carried down toward the inferior orbital rim. This  maintains the plane anterior to the orbital septum. Retraction  sutures may be placed on the vestibular portion of the con-  junctival flap with traction in superior direction, to provide  additional protection to the globe. On reaching the facial sur-  face of the infra-orbital rim, the periosteum is incised about    Fig. 57.25 (a) Diagram showing trans-conjunctival approach and its modifications - A. Transconjunctival, B. Trans-caruncular & C. Lateral  canthotomy. (b) Intra-operative picture of trans-conjunctival with the lateral canthotomy modification. The picture also shows an upper lid blepha-    2 mm inferior to the rim. This is followed by subperiosteal  dissection and exploration of the orbital floor by retracting  the globe and orbital contents superiorly. Approximately  2-3 mm distance must be maintained from the lower end of  the tarsal plates while making the initial conjunctival inci-  sion failing which there is vertical shortening of the lower  eyelid and entropion post-operatively.    Fig. 57.26 Diagrammatic representation of the pre-septal and retro-  septal modifications of the transconjunctival approach   In the retroseptal type, the conjunctival incision is made near  the fornix spanning mediolaterally just short of the caruncle.  Dissection is posterior to the orbital septum providing a fast  and direct access to the floor when compared to the pre-  septal type [38]. However, orbital fat is encountered before  approaching the orbital floor, which may prove bothersome  for dissection and manipulation. The periorbita is incised  immediately posterior to the rim after superior retraction of  the fat and globe with a malleable retractor. This is followed  by subperiosteal dissection and exploration of the floor  defect. Excessive manipulation of the orbital fat during  orbital reconstruction increases the risk of enophthalmos due  to fat disintegration [39, 40]. Placement of the incision too  low into the fornix may damage the inferior oblique muscle  and retractors of the lower eyelid, compromising esthetics  post-operatively due to lower lid entropion.    The trans-antral approach was attempted by Converse and  Smith [41] as early as the 1960s. Entry to the antrum is  gained through a transoral Caldwell Luc procedure and a 0°  or 30° endoscope may be used to visualize the orbital floor.    The coronal approach offers the most extensive exposure of  the entire upper and middle third of the face including the  orbit. A detailed description of the same is provided in Chap.  85 on access osteotomies.    Fig. 57.27 (a, b) Diagram of the trans-antral endoscopy assisted approach to the orbital floor    57.8 A Clinical Sequence for Treatment  Planning and Management of Orbital  Fractures    A clear understanding of the various patterns of orbital frac-  tures and their clinical implications is absolutely necessary  to design and formulate a plan for their reconstruction. The  basic management guidelines for the common variations in  orbital fractures are detailed below (see Hammer [7] classifi-  cation, Fig. 57.9).    Concomitant fractures of the zygomatic complex and the  orbit mandate ORIF of the zygomatic complex first, fol-  lowed by internal orbital reconstruction. This sequence is    Fig. 57.28 3D CT scans of  patient with orbito-zygomatic  fracture. (a and b) Pre-  operative frontal and basal  views demonstrating the  fracture, (c and d) post-  operative frontal and basal  views demonstrating fixation  of fractures    favored because the orbital rims provide the most accurate  guidance for restoration of the internal orbital architecture.    e Restoration of transverse dimension of the face,  malar prominence, and the arch anatomy    Fig. 57.29 Axial and sagittal  scans of the patient in Fig   , with orbito-zygomatic  fracture. (a and b) Sections  demonstrating fracture of the  left zygomatic complex with a  large defect of the orbital  floor. (c and d) Post-operative  sections revealing optimal  reduction of the fracture and  floor reconstruction with  anatomical orbital floor  implant    Management of type II orbital fractures, which are essen-  tially the internal fractures (both blow-in and blowout) of the  orbit including (1) the roof, (2) the floor, and (3) the medial  and (4) lateral walls are detailed below.    Box 57.9 The Management of All Internal Orbital  Fractures Can Be Handled Essentially by Answering the  Following Basic Questions (Clinical Tip)    (i) Is there a need for intervention?  (11) When is the best time to intervene?  (iii) Is there a need for reconstruction?  (iv) What to use for reconstruction?   Isolated fractures of the orbital roof are extremely rare. They  usually occur as a part of fronto-basilar fractures, fractures of  the frontal sinus, or may occur concomitant with fractures of the  supraorbital rim. Orbital roof fractures are present in approxi-  mately 5% of all orbital and cranial fractures, while incidence of  isolated orbital roof fractures may be as low as 0.7% of all  orbital and cranial fractures. The most common etiological fac-  tors include motor vehicle accidents, assaults, or falls.   Orbital roof fractures may be associated with more severe  neurological symptoms including dural tears, CSF leak, ten-  sion pneumocephalus, diffuse cerebral edema, and contu-  sions of the frontal lobe [42]. Itis imperative for a neurological  and ophthalmological consult prior to management.   In general, orbital roof fractures may be categorized into  four types (Fig. )).    Fig. 57.30 CT scan images  showing types of roof  fractures (a) blow-in fracture,  (b) blowout fracture, (c)  fracture of the supraorbital  rim, and (d) fronto-basilar  fracture    I—Blow-in fractures of the orbital roof where there is  caudal displacement of the orbital roof with or without  herniation of the brain. These may be undisplaced or dis-  placed fractures. Comminuted fractures may leave frag-  ments within the orbital cavity and may produce functional  deficits with ophthalmic signs including restriction of  extraocular muscle movement, diplopia, ptosis, and even  blindness. These are generally caused due to increase in  the intra-cranial pressure secondary to injuries.  II—Blowout fractures of the orbital roof where there is  cephalad displacement of the orbital roof into the cranial  cavity due to increased intra-orbital pressure pushing the  roof above. These injuries may be associated with neuro-  logical symptoms.   IU—Fractures involving the supraorbital rim. These may  be seen as impure fractures of the orbital roof with an  associated fracture of either a blow-in or a blowout nature.  IV—Fractures involving the frontal sinus and the fronto-  basilar complex. These fractures are more severe in nature   Less than 10% of orbital roof fractures may need any  form of surgical intervention [42]. Most are amenable to  conservative management with observation and follow-up of  neurological and ophthalmic status.    The need for management of fractures of the orbital  roof may depend on:   (i) The presence of CSF leak which may need to be  addressed   (iv) Large displacement of fragments which may  act as mechanical impediments or signifi-  cantly alter intra-orbital volume producing  enophthalmos or exophthalmos.    Interventions may be indicated immediately or late pri-  mary depending on the indications mentioned above.  Reconstruction of the roof of the orbit is not a proce-  dure routinely indicated. However in cases where there  is an absolute necessity for reconstruction like preven-  tion of brain herniation or restoration of intra orbital  volume which has been significantly altered, the choice  may vary between the use of titanium meshes  (Fig. 57.31) or porous polyethylene implants fixed with  micro-screws to split calvarial grafts.   Figure 57.32a—f demonstrates the management of a mal-  united fronto-basilar fracture along with a blow-in fracture  of the orbital roof compressing the eyeball producing restric-  tion of movement.    57.8.2.2 Fractures of the Lateral Orbital Wall  Lateral orbital walls are the strongest of all the orbital walls  [43]. The lateral wall generally shows diastasis and dis-    Fig. 57.31 Reconstruction of complex defect of the frontal bone,  orbital roof, and supraorbital rim with a titanium mesh    placement in the case of fractures involving the  zygomatico-orbital complex and is restored to its normal  anatomy when the reduction of the zygomatic complex is  achieved [44]. However this wall gets comminuted in high-  velocity injuries [45] necessitating reconstruction in the pri-  mary intervention.   The anatomy of the lateral wall plays an important role in  the internal orbital volume as demonstrated by development  of enophthalmos in unrestored lateral wall fractures [46].  Restoration of the architecture or augmentation of the same  ensures correction of enophthalmos.   (i) Alloplasts including titanium meshes, porous  polyethylene sheets, and custom-made poly-  ether ether ketone (PEEK ) implants   (ii) Bone grafts which may be harvested from either  the calvarium or ilium    Figure 57.33a, b demonstrates the management of frac-  ture of the lateral walls of the orbit in a patient with concomi-  tant fracture of the zygomatic complex.   The medial wall and the floor are the thinnest walls of the  orbit and have the propensity to fracture the most [47, 48].  Though the incidence of concomitant fractures of the medial  wall with that of the orbital floor have been reported over a  wide range of 5—71%, its occurrence in isolation is very rare.  Most fractures of the medial wall are incidental findings  when CT scans are obtained to study other cranial, facial, or  orbital fractures.   The most common type of clinical presentation would  either involve a combination of the medial wall and floor  (36%) or medial wall, floor, and zygomatic complex (28%)  [49-51].   Fractures of the medial wall were managed conserva-  tively in the past, but current literature proposes clear indica-  tions [49-51] for the exploration and reconstruction of the  medial wall fractures and defects, which include:   1. Restriction of ocular motility  2. Diplopia  3. Clinically significant enophthalmos    Fig.57.32 CT images of patient with malunited fractures of the orbital images showing recontouring of the supraorbital rim and roof using  roof. (a-c) Pre-operative images demonstrating malunited fracture of ultrasonic aspirator system, with resultant expansion of the intra-orbital  the frontal bone and orbital roof of the left side with decrease in intra- | volume    Fig. 57.33 CT scan images of lateral orbital wall with concomitant image showing reduction of the lateral wall and re-establishment of the  fracture of the zygomatic complex. (a) Pre-operative image showing sphenozygomatic suture continuity  fracture and displacement of the lateral wall and (b) post-operative    Box 57.10 A Clinically Useful Classification of Medial Wall Fractures Has Been Described by Nolasco et al. [47] in 1995  Based on CT Scan Findings   e Type II: Fracture involving the medial wall and the orbital floor   e Type III: Fractures involving the medial wall, floor, and the zygomatic complex  e Type IV: Medial wall plus complex fractures of the face (maxillary, NOE, etc.)    Fig. 57.34 CT scans showing types of medial wall fractures. (a) Isolated medial wall fracture; (b) fracture of medial wall with  floor; (c) fracture involving medial wall, floor and zygomatic complex; and (d) concomitant fractures of the medial wall, floor, and  midface at LeFort 3 level    Contrary to earlier belief the loss of medial wall integrity  also significantly contributes to development of enophthal-  mos [49]—with any defect involving an area of more than  1.9 cm? or volume expansion of excess of 0.9 ml [50, 51] pro-  ducing clinically significant enophthalmos (2 mm or more).   Approaches to the medial wall have already been  described in detail earlier. The most favored being the trans-  caruncular/retro-caruncular approaches which give excellent  exposure and access to the medial wall for both exploration  and reconstruction [37, 52].   Options for reconstruction include a multitude of materi-  als which may be autogenous or alloplastic as shown in  Table 57.1. Bioactive resorbable sheets are also found to pro-  duce good outcomes [53].   Figure 57.35a, b demonstrates reconstruction of a medial  wall fracture with a Titanium mesh.   The fractures involving the orbital floor are the most com-  mon fractures of the internal orbit either in isolation or con-  comitant with other facial fractures. A comprehensive  classification of floor fractures with clinical guidelines for  management is described by Jaquiery [54] et al. which lays  emphasis on the morphology of the defect and the role of the  infero-medial strut of the inferior orbital fissure.    The internal orbit is divided into three zones which  helps in evaluating the difficulty of approach and  exposure:    Permeability for  Stability / Biological inflammatory Donor site Radio-  Material fixation (S/F) Contouring behavior exudate morbidity opacity Availability  Titanium S4+++ ++ ++ (allows tissue + + + +  F+t+ in-growth)  Bone graft S++ = +++ = = +p +/—  By  Porous polyethylene S+/— ar ++ (allows tissue = — +P = +  F+/— (when in-growth)  thin)  Composite porous S++ ar ++ (allows tissue = — + + +  polyethylene/Ti Et in-growth)  Resorbable (PLLA) S+/— + + (inflammatory (non-perforated) + = +  Bt/> response)  Pre-formed S4+4++ +++ (minimal ++ (allows tissue + + - +  anatomical implant F++ contouring needed) in-growth)    Fig.57.35 CT images of patient with medial wall fracture. (a) Fracture of the medial orbital wall of the left orbit showing displaced medial rectus.  (b) Post-operative image demonstrating medial orbital reconstruction with titantum mesh    Table 57.2 The classification of orbital wall defects (Jaquiery et al.    Defect description  Isolated defect of  floor or medial  wall, 10-20 mm?  within zone | or 2  Defect of floor and/  or medial wall   >20 mm? within  zone | and 2  Defect of floor and/  or medial wall   >20 mm? within  zone | and 2  Defect of the entire  orbital floor with  medial wall  involving zone 3    Bony infero-medial  strut of the inferior  orbital fissure  present  Infero-medial strut  of inferior orbital  fissure absent    Infero-medial strut  of inferior orbital  fissure absent. The  posterior ledge of  the floor also may  be absent   Indications and contraindications for floor exploration and  repair are well defined.   1. Acute injury to the orbit showing evidence of immediate  clinical enophthalmos and/or hypophthalmos [55]  (Fig. 57.15), necessitating a primary surgical interven-  tion. Post-surgical outcome may get compromised with  delay due to progressive atrophy of intra-orbital fat.   2. Severe restriction of ocular motility with CT or MRI evi-  denced muscle entrapment or incarceration of periorbital  soft tissue.    Fig. 57.36 Diagrammatic representation of the different types of defects of the orbital floor which indicate the grades of difficulty to reconstruct.    (a) Type I, (b) Type II, (c) Type II and (d) Type IV    Fig. 57.37 CT scan images of a young boy with history of orbital inferior rectus muscle. (Courtesy: Dept of Orbit & Oculoplasty,  trauma. (a) Sagittal and (b) coronal sections demonstrating a “springing Shankara Nethralaya, Chennai)  trapdoor” fracture of the orbital floor on the left side with entrapped    Fig. 57.38 Clinical photographs of a boy with “White eye blowout” abnormalities. (Courtesy: Dept of Orbit & Oculoplasty, Shankara  fracture, showing restriction of ocular motility in the left eye in the | Nethralaya, Chennai)  superior (a) and inferior (e) gazes. The other gazes (b, ¢ and d) show no    3. “White eye blowout” fracture in a child or young adult  with severe restriction of ocular motility (Figs. 57.37a, b  and 57.38) and vagal symptoms.   1. Defects of the orbital floor often larger than 50% of the  orbital floor area or greater than 20 x 20 mm of defect  size especially in the zone between the floor and the  medial wall (Fig. 57.39a).   2. Diplopia which is non-resolving and persistent for more  than 2 weeks due to entrapment or fibrosis of orbital soft  tissue (Fig. 57.39b) [56, 57].    Relative Contraindications  1. Associated ophthalmic injuries like retinal tears,  hyphema, displacement of lens, ruptured globe, avulsion  injuries of the globe, etc.  2. Loss of vision in one eye with the only seeing eye involved  in a fracture  Figure 57.40a—f demonstrates the delayed management  of a patient with an isolated fracture of the floor and medial  walls. The CT scan shows fibrosis and adhesion of the infe-  rior rectus muscle to the residual posterior ledge producing  diplopia and restriction in superior gaze.   Enophthalmos is the displacement of the eyeball in a pos-  terior direction and is attributed to increase in the intra-  orbital volume. Numerous studies have shown that there is a  correlation between increase in intra-orbital volume and the  presenting enophthalmos. It is proved that an increase in  intra-orbital volume by 0.5-1 cc would produce posterior    Fig. 57.39 (a) Sagittal  section CT demonstrating  large defect of the orbital  floor. (b) Sagittal section CT  demonstrating fibrosis and  adhesion of the inferior rectus  (yellow arrow) to the  posterior ledge of the orbital  defect    displacement of the globe by 1 mm. Enophthalmos of 2 mm  or more may be clinically perceivable and warrant surgical  intervention [58, 59]. An important aspect of orbital recon-  struction lies in the fact that it is the only fracture in CMF  region where the onus is not in recreating the anatomical  form but rather in the restitution of the intra-orbital volume.  Care should be taken to reconstruct the posteromedial aspect  of the orbit (Hammer’s key area) to achieve anterior projec-  tion of the globe. It is imperative to understand that recon-  struction of the floor posterior to the equator of the globe  influences anterior projection of the globe, while reconstruc-  tion of the equatorial region of the floor influences only the  supero-inferior position of the globe (Fig. 57.41).   Figure 57.42a—d shows a case of delayed correction of  enophthalmos in a patient with an orbital floor fracture.   This is otherwise called hypoglobus and signifies the down-  ward displacement of the globe due to the interruption in the  anatomical integrity of the orbital floor. The clinical presence  of hypoglobus needs to be differentiated from orbital dysto-  pia which essentially means that the entire bony orbit with its  contents is displaced caudally, unlike hypophthalmos, where  only the globe is displaced caudally.   However decision-making for surgical intervention based  on both enophthalmos and hypophthalmos is challenging as  they may or may not present immediately following trauma.  (Refer to clinical scenario 1. Figs. 57.57, 57.58 and 57.59).   Clinically demonstrable double vision is termed diplopia.  Generally post-traumatic diplopia due to edema and hemor-  rhage is self-limiting and shows spontaneous resolution.    Fig. 57.40 CT scan images of patient with internal orbital fracture. (a—c) 3D  left orbital floor and medial wall. (d—f) post-operative images demonstrating r    Fig. 57.41 Graphical representation of the equator of the globe (E)  and the associated equatorial (A) and post-equatorial (B) zones of the  floor    , coronal, and sagittal images demonstrating isolated fracture of the  econstruction of the defect with anatomical orbital implant   Monocular (diplopia present when seeing through one  eye with the other eye closed) which is of more concern  where the pathology is generally due to an ophthalmic  problem (corneal, retinal, etc.) or neurological where the  problem may be due to the optic nerve or the optic disk  being injured.   Binocular diplopia (diplopia present only when seeing  with both eyes, while absent on seeing with one eye)  with CT proven muscle entrapment is seen as an indica-  tion for immediate intervention. However, it may also be  attributed to other reasons including (a) intra-orbital  edema or hemorrhage, physical bony spicules or frag-  ments acting as impediments following trauma, (b)  entrapment of the periorbita, and in rare cases (c) large  changes in intra-orbital volume including massive    Fig. 57.42 Clinical photographs of patient with enophthalmos. (a and b) Pre-operative pictures demonstrating significant enophthalmos of the  left globe. (¢ and d) Post-operative pictures demonstrating good surgical outcome    herniations or atrophy of periorbital fat, which do not  mandate immediate intervention. Refer to clinical sce-  nario 2.    When Is the Right Time to Intervene?  The timing for intervention for fractures of the orbital floor  can be divided into three categories—immediate, early, and  late. The indication for all three categories are well discussed  in literature [57] and are listed in Fig. 57.43.   Indications for immediate repair are of an urgent nature  and may require priority as surgical emergencies, generally  less than 6 h following trauma.   A plethora of material both autogenous and alloplastic  have been used and documented. A table is provided with  the list of the most commonly used materials and their  relative merits (Table 57.1). However, contemporary liter-  ature favors the use of stock titanium meshes and custom  patient specific implants which provide optimal correc-  tions (Fig. 57.44a, b).    Guidelines for Deep Orbital Dissection  The dissection of the deep orbit is always a challenge for the  surgeon due to the high concentration of vital structures   (a) Infra-orbital nerve: the course of the infra-orbital nerve  within the orbit is a very important landmark in floor  dissection. The point of its entry from the pterygopala-  tine fossa at the genu/bend where inferior orbital fissure  takes a turn and ascends laterally to continue as the  superior orbital fissure signifies the safe limit for the  posterior extent of floor dissection. Even in the case of  badly comminuted fractures or delayed corrections, the  nerve may be identifiable and provides a reliable clue to  the end of the pre confluence area.   (b) Inferior orbital fissure: the inferior orbital fissure forms  a pathway for an extended exposure of the lateral orbit  as the contents of the fissure can be safely divided using  bipolar cautery dissection. This facilitates easy naviga-  tion into the deep orbit behind the fissure and trace the  greater wing of sphenoid. It may be of clinical relevance  to note that the structures of the lateral orbit are much  stronger and less prone to comminution when compared  to the medial orbital structures. This makes the lateral  approach to the deep orbit more predictable. Furthermore,    the medial strut of the inferior orbital fissure is an impor-  tant entity to identify and utilize for reconstruction of the  internal orbit.   The greater wing of the sphenoid: this is a thick and  strong bony structure which forms the majority of the  lateral orbit and bridges the inferior and superior orbital  fissures. Its robust nature makes it less prone for com-  minution and hence forms a predictable landmark to find  even in severe trauma.   Orbital process of the palatine bone: the Orbital process  of the palatine bone forms the highest point of the poste-  rior-medial bulge of the orbital floor. This is an integral  part of the posterior orbit that needs to be reconstructed  to get adequate positioning of the globe in the anteropos-  terior and vertical directions.   Orbital confluence: the orbital confluence (Fig. 57.45a,  b) is formed by the convergence of two bony shelves  forming the genu of the internal orbital fissures. This  signifies the safe limits of the dissection of the orbital  floor. The confluence is formed by the perpendicular  plate of the palatine bone on the medial aspect and the  bony inferior margin of the greater wing of the sphenoid  laterally.    (f) Safe distances within the orbit: an important formula to (g) Globe protection: protection of the globe is of vital    remember safe distances within the orbit is 24-12-6, importance in orbital surgery. Adequate care should also  where 24 is the distance in mm of the anterior ethmoidal be exercised for the protection of other vital structures  foramen from the medial orbital rim; an additional like nerves and vessels also. Use of protection devices  12 mm deeper (36 mm) would indicate the posterior eth- like specific retractors (Fig. 57.46a, b, c) and corneal  moidal foramen followed by another 6 mm deep for the shields is mandatory.    Fig. 57.45 (a) Demonstration of landmarks on dry skull. (A)  (b) Intraoperative photograph demonstrating the structures of the deep  Perpendicular plate of the palatine bone. (B) Medial lip of the greater _ orbit in a patient undergoing secondary surgery for floor reconstruction  wing of the sphenoid. (C) Orbital confluence and (O) Optic foramen. _ with implant replacement    Fig.57.46 Photographs showing globe protection devices. (a) Stryker® globe retractor, (b) Synthes® globe retractor and (c) Synthes® retractor in  anatomical position demonstrating the use of calibration to aid intraoperatively    Fig.57.47 CT scans images demonstrating optimal de-herniation of orbital contents and restoration of intra-orbital volume. (a—c) Pre-operative,    Two important aspects of floor reconstruction are:  (i) De-herniation of the orbital (Fig. 57.47a—f) con-  tents to restore the internal orbital volume  (ii) Locating the posterior ledge (Fig. 57.48a—d) for  optimal implant positioning    However, locating the posterior ledge in large defects and  secondary corrections may be a significant challenge.  Absence of posterior ledge in severe orbital trauma is an  indication for cantilevered implants which are secured to the  infra-orbital rim alone.    The NOE-type fractures are the most challenging of all the  orbital fractures to manage in terms of achieving predictable  results. The management of the NOE complex reconstitutes  the facial form of the central midface: a key element in facial  esthetics. This type is also prone to have concomitant inju-  ries to the lacrimal system which should be identified and  treated.   Figure 57.49a—f demonstrates the CT images of a patient  with a residual deformity following pan-facial trauma with  a right-sided type I NOE and neglected orbital floor  fractures.    (a and b) Pre-operative coronal and sagittal section CT images demonstrating the location of the posterior ledge of the floor defect. (c  and d) Post-operative images showing the placement of the anatomical orbital floor implant in the appropriate position to bridge the defect    Fig. 57.49 CT scan images of patient with type I NOE fracture, plus  orbito-zygomatic complex on the right side. (a—c) 3D, coronal and sag-  ittal images demonstrating the fractures and the floor defect. (d—f) Post-    ¢ Management of the medial canthal tendon (MCT)  as indicated: this can be performed according to the  description of Markowitz et al. [61] with the focus  being the attachment or avulsion of the medial can-  thal tendon (MCT) to the fracture fragment   ¢ Management of the soft tissue drape after reposition  of the MCT   ¢ Restoration of the nasal dorsum projection, which  is of paramount importance   e Evaluation of injuries to the lacrimal system: cana-  liculi, sac and the nasolacrimal duct (NLD), and its  management    This type includes all the combinations of the fractures of the  face which do not fall into the types described above.  Sequencing of fractures (refer Chap. 60) such as these includ-  ing pan-facial fractures requires a thorough understanding of  the principles to obtain optimal outcomes. It is to be borne that  sequencing and fixation of all facial fractures need to be com-  pleted prior to the reconstruction of the internal orbit.    operative images demonstrating ORIF of the right NOE fracture, redo  of the orbito-zygomatic complex and floor reconstruction with anatom-  ical orbital implant    Figures 57.50a—d and 57.5la—d demonstrate a patient  with residual facial deformity following RTA. Patient had  sub-optimally treated pan-facial and orbital fractures and a  malunited mandible fracture. He was operated for a revision  surgery addressing his midface and dental occlusion.    (a) Retrobulbar hemorrhage: investigations with a CT scan  or an MRI as the clinical situation mandates help us with  a diagnosis of retrobulbar hemorrhage. 20% mannitol  2 g/kg body weight or 500 mg acetazolamide is admin-  istered to reduce the intraocular pressure in conjunction  with 100 mg hydrocortisone for management of edema.  Hourly examinations of pupils, visual acuity, and IOP  are of great significance as stable ophthalmic status with  diminishing signs of vision can be managed medically.  Deterioration of vision or changes in visual fields may  be considered an emergency [62]. Inferior cantholysis is  the most commonly employed procedure for decom-  pression of the retrobulbar space [63-65].   Traumatic optic neuropathy: the management of trau-  matic optic neuropathy includes observation, use of ste-  roids, and surgical decompression [66]. However, the  use of corticosteroids in acute brain trauma is now  debatable, and the general consensus is non-use of ste-  roids in patients having concomitant brain trauma [67].  Many clinicians now restrict the use of steroids (bolus    Fig. 57.50 3D CT images of patient with neglected pan facial injury  and associated orbital fracture. (a and b) Images demonstrating frontal  and lateral views showing malunited pan-facial fracture with facial  deformity and significant dental malocclusion. (¢ and d) Post-operative    dose of 30 mg/Kg body weight of methyl prednisolone  followed by 3 mg/Kg/h for 24 h) within the first 8 h of  injury, in cases of severe primary vision loss or progres-  sive vision loss.   (c) Compartment syndromes: this includes both superior  orbital fissure and orbital apex syndromes. The current  protocols indicate early surgical decompression where  indicated. The role of steroids is debatable as indicated  above.    Pediatric consideration in orbital trauma necessitates the dis-  cussion of four important aspects which clearly delineate the  management principles from adults.    images demonstrating ORIF of the right orbito-zygomatic complex and  a Lefort I osteotomy with restoration of skeletal form, midface projec-  tion, and restoration of functional occlusion    (a) Ratio of cranium to facial fractures in children  The face to cranium ratio of an infant is 1:8, while that  of a child who is between 4 and 6 is about 1:4. This  clearly establishes the fact that the cranium in an infant  or a child is much larger than the face and is more  exposed to potential trauma. The incidence of orbital  roof fractures is much more common in children who  are younger than 5 years, while beyond the age of 7, the  floor fracture is more commonly seen.   (b) Pediatric orbital roof fractures  Roof fractures in children occur in the growing age [68]  and cause an entity called the “growing skull fracture,”  where the fracture fragments continue to separate due to  growth, causing “leptomeningeal” herniation which  involves herniation of the meninges and part of the frontal  lobe into the orbital cavity. Management of these need to  be planned in conjunction with neurosurgical support.    Fig. 57.51 Coronal and axial CT images of the patient in Fig 57.50. (a and b) Images demonstrating comminuted fractures of the midface and  orbit. (¢ and d) Post-operative images showing optimal restoration of form of the face and orbit    Fig. 57.52 Clinical photographs of a 6-year-old child with left sided orbital trauma (a and ¢) frontal and basal views demonstrating immediate-  onset enophthalmos and hypophthalmos. (b and d) post-operative photographs showing optimal post-surgical outcome. (Courtesy: Dept of Orbit  & Oculoplasty, Shankara Nethralaya, Chennai)    Fig. 57.53 CT scan images  (a) 3D image demonstrating  fracture involving the left  infra-orbital rim and orbital  floor in a 6 year-old child, (b)  sagittal sections of both orbits  showing left sided floor  fracture. (Courtesy: Dept of  Orbit & Oculoplasty,  Shankara Nethralaya,  Chennai)    (c) White eye blowout  The presence of floor fractures with restriction in superior  gaze, with or without oculo-vagal responses and devoid of  any physical signs of hemorrhage or ecchymosis in the  eye or periorbital region [69-71]. This is a feature which  may be seen in children and young adults as a result of a  “self-reducing trapdoor” fracture which entraps the infe-  rior rectus. The white eye blowout is considered a surgical  emergency and necessitates immediate intervention.   (d) Role of resorbable implants  The cranium and upper face exhibit rapid growth in the  early years. The orbit completes almost 80% of its  growth within the first 2 years of life and another 10%  within the next 2-3 years. Choice of implants in the  growing orbit is to be taken into consideration by the  surgeon who has to plan for the residual growth of the  orbit and possible chances of migration of implants.    Secondary corrections of the internal orbit demand great  degrees of skill and are technically demanding even for the  trained surgeon due to the nature of fibrosis and contracture    that is already set in and the distortion of bony landmarks  within the orbit. This may necessitate more extensive dissec-  tion and mobilization of the orbital contents and yet yield  sub-optimal outcomes.    Complications associated with management of orbital frac-  tures may be categorized into immediate and delayed  complications.    Box 57.12 Indications for Secondary Deformity  Correction of the Internal Orbit Generally Are    (a) Restricted ocular movement, which may be either  due to muscle entrapments or adhesions of intra  orbital and/or periorbita   (b) Diplopia due to physical impediments like bony  interferences and/or soft tissue adhesion/  entrapment    The most common immediate complications that are  secondary to orbital surgery include:    Hemorrhage may be an infrequent complication which  may happen during the surgery or in the immediate post-  operative period.   Complications associated with specific ophthalmic impli-  cations like injuries to the cornea, extraocular muscles, lacri-  mal apparatus, or the optic nerve also may occur.   Blindness is a rare but grievous complication which has to  be borne in mind.   The last group includes neurosensory disturbances like par-  esthesia or dysesthesia associated with the infra-orbital nerve  and carrying grades of facial nerve palsy or weakness [72, 73].    Orbital reconstruction still remains one of the most challeng-  ing and enigmatic areas in the management of cranio-facial  trauma and most certainly attracts the latest in terms of tech-  nology and developments to refine and improve outcomes.  Significant advances in the field of orbital reconstruction  include:    1. Computer-assisted surgery  2. Intraoperative imaging and navigation (refer Chap. 41)  3. Patient-specific implants for reconstruction    Computer-assisted surgery allows virtual pre-operative  planning of the desired reconstruction using pre-operative  CT scans (Fig. 57.54a—d) [74]. This virtual plan gives real-  time guidance during surgery. Navigation helps visualize  the actual surgical outcome during surgery in relation to  the pre-operative plan (Fig. 57.55). With this technique,  sub-optimal reduction of fractures and positioning of  implants can be identified and corrected during surgery,  thereby reducing the need for secondary procedures  [75-77].    Custom implants for the reconstruction of complex defects  and deformities have become vogue now. They offer the  advantages of accurate planning and infallible positioning  intraoperatively which enormously improve post-surgical    Fig. 57.54 Photographs depicting stages in computer-assisted surgery _ the deformity; and (d) creation of patient specific implant design for the  for orbito-facial reconstruction. (a) Generation of virtual 3D model; (b) —_ fronto-zygomatic region and importing the virtual model of the ana-  segmentation and mirroring of normal side; (c) superimposition of the  tomical orbital implant for floor reconstruction   mirrored object on the affected side, enabling a better understanding of    outcomes. The defect can be mapped digitally and a con-  struct can be made after virtual surgical planning to aid in Box 57.13 Principles to Be Followed During Surgery for  intraoperative guidance. The implants may also function as Orbital Floor Reconstruction    (ii) Meticulous de-herniation of the orbital soft tis-  sues with restitution of intra-orbital volume   (iii) Identification of the posterior ledge in floor  defects which is the posterior limit for  reconstruction   (iv) Restoration of the posteromedial bulge of the  orbit (Hammer’s key area) [7]   (v) Choice for the reconstruction material should be  based on the complexity of the defect (Dubois  et al.) [55]    To conclude, all patients with orbital trauma need to be subjected  to ophthalmological examinations both pre- and post-surgery.  Globe protection, gentle retraction of tissues, and intraoperative  testing for vision are mandatory during orbital surgery.    Fig. 57.55 Screenshot images of a left-sided orbital floor with an anatomical orbital floor implant that is virtually planned and executed with the  help of intraoperative navigation    Fig. 57.56 PSI designed for reconstruction of a large floor and medial wall defect in the right orbit. (a) Frontal view of PSI on an STL model of  the patient, (b) superior view, and (c) intraoperative photograph showing placement of the PSI “in situ”    Patient with a history of facial trauma 8 months back presented with complaints of change in the position of his eye-  balls. He had a history of surgical intervention for management of his pan-facial fractures immediately following the  trauma. No intervention was performed for the orbital fractures primarily. Subsequent clinical evaluation performed 8  months later revealed enophthamos, hypophtalmos and restriction in superior gaze in the right eye. CT scans revealed  a large orbital floor defect on the right side with fibrosis and adhesion of the inferior rectus to the posterior ledge of the  floor defect. The patient was subjected to secondary surgery for correction of the above mentioned complaints. An  orbital exploration was performed on the right side to release the inferior rectus, the infra-orbtial rim was augmented  with a ramal graft and the floor defect was reconstructed with a “Stryker” anatomical orbital implant. Post-surgical  evaluation revealed optimal corrections of the enophthalmos, hypophthalmos and good repositioning of the inferior  rectus muscle (Figs. 57.57a—d, 57.58a, b and 57.59a-f).    Fig. 57.57 (a and b) Pre-operative clinical photographs of patient demonstrating right sided enophthalmos and hypophthalmos. (¢ and d)  Post-operative clinical photographs showing optimal surgical outcomes    Fig. 57.58 3D CT reconstructions of patient in Fig 57.57 demonstrat- the right orbital floor defect with an anatomical orbital implant after  ing (a) right-sided malunited zygomatic complex fracture with orbital | augmentation of the infra-orbital rim with a mandibular ramus bone  floor defect and (b) post-surgical scan image showing reconstruction of _ graft    Fig. 57.59 (a—c) Pre-operative axial, coronal, and sagittal scans of patient in Fig 57.57 with large defect of the right orbital floor. (d—f) Post-  operative sections demonstrating the correction of the floor defect with an anatomical orbital implant   A 12 year old girl presented to the surgical OPD with history of blunt injury to the left eye. On examination she had no  external signs of injury but revealed restriction in superior gaze in the left eye. CT scan revealed a springing trapdoor  fracture of the left orbital floor with entrapment of the inferior rectus muscle. A diplopia charting was performed which  revealed moderate to severe restriction of the left eye in the superior gaze. The patient was taken up for immediate  surgery for orbital exploration and release of the entrapped muscle with/without floor reconstruction. The exploration  was successful and the patient required no reconstruction of the floor. Post operatively the patient demonstrated com-  plete resolution of the symptoms with the full range of ocular movements restored. (Figs. 57.60, 57.61, 57.62a, b)  (Courtesy: Dept of Orbit & Oculoplasty, Shankara Nethralaya, Chennai)    Fig. 57.60 Pre-operative photograph demonstrating the nine gazes of a young girl with a “White eye blowout” fracture of the left orbital  floor with entrapment of the inferior rectus. (Courtesy: Dept of Orbit & Oculoplasty, Shankara Nethralaya, Chennai)    Fig. 57.61 Post-operative photograph demonstrating resolution of symptoms after 3 weeks of surgery (Courtesy: Dept of Orbit & Oculoplasty,  Shankara Nethralaya, Chennai)    Fig. 57.62 Photograph of documentation of diplopia by charting with two colors (green for left and red for right eyes). The left and right sides  are marked in the orientation that the patient sees an object in front of him/her. (a) Pre-operative and (b) post-operative (Courtesy: Dept of Orbit  & Oculoplasty, Shankara Nethralaya, Chennai)    . Ochs MW, Buckley MJ. Anatomy of the orbit. Oral Maxillofac    raphy: especially on the growth of the orbit. Jpn J Ophthalmol.  2001;45(6):600-6.    . Bron AJ, Tripathi RC. Wolff’s anatomy of the eye and orbit.    . Manson PN, Clifford CM, Su CT, Iliff NT, Morgan R. Mechanisms    of global support and posttraumatic enophthalmos: I. 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Br J Oral Maxillofac Surg. 2005;43(5):410-6.    Open Access This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.  org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropri-  ate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.   The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in  a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.   Naso-orbito-ethmoid (NOE) region is a confluence of criti-  cal structures of the face including the nose, orbit and skull  base. Hence injuries to the region have a major impact on the  function of these regions as well as aesthetics. A deformity  of the NOE region tends to catch the eye much more than a  deformity elsewhere in the face and hence affecting the indi-  vidual. The injuries to this area are about 5% of maxillofacial  injuries in adults and about 15% in children [1, 2] and mostly  occur as a result of road traffic accidents (RTA) [1] espe-  cially in the Indian subcontinent. This is especially so due to  two-wheeler injuries. Considering the proximity of the  region to the brain and globe, these injuries may need multi-  disciplinary evaluation before embarking on a definitive  treatment plan.    The NOE complex is a part of the medial vertical buttress  system of the face abutting the cranium. It is made of the  nasal bones, the ethmoid bones encompassing the sinuses  which also form the medial wall of the orbit articulating  above with the frontal bone at the anterior skull base. This  ethmoid labyrinth which separates both the orbits acts like a  shock absorber during trauma thus minimizing force dissipa-  tion into critical structures like the orbital and cranial cavi-  ties. Extensive injury or comminution can result in associated  anterior cranial base fractures causing cerebrospinal fluid  (CSF) leak as well. The frontal process of maxilla and the  lacrimal bone also is an integral part of the complex owing to  their proximity and involvement in the fracture pattern  occurring in the region.    K. Balaraman   Department of Oral and Maxillofacial Surgery, Ganga Medical  Centre and Hospitals, Coimbatore, Tamil Nadu, India    © The Association of Oral and Maxillofacial Surgeons of India 2021    Apart from the bony parts, the medial canthal ligament  (MCL) is an important soft tissue of the complex (Fig. 58.1).  The ligament not only anchors the upper and lower eyelids to  the nasal complex but also encompasses the lacrimal sac at  its anterior, posterior and superior aspect [3]. Certain authors  have found that the posterior limb is not always present or  clearly defined in certain instances [4]. The ligament being  attached to the edges of the lacrimal fossa in the lacrimal  bone in these areas helps in emptying of the lacrimal sac dur-  ing blinking thus effecting drainage of the lacrimal sac.  Hence injuries to the region affecting the attachment of the  medial canthal ligament can impact the medial eyelid attach-  ment and/or draining off tears from lacrimal sac. The skin  and soft tissues drape over the complex like a cloth over a  framework, and when the region crumples following an  injury, the soft tissue envelope collapses as well causing dis-  tinct deformity which if not treated well can result in persis-  tent deformity of the region. The collapsed soft tissue heals/  scars over the deformed bony complex and secondary cor-  rection at a later date do not help achieve the pre-injury sta-  tus. Hence optimal primary realignment and repair offer the  best chance of achieving optimal results [5].    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1-15-1346-6_58    The treatment of NOE complex injuries has evolved from the  previous century. Though nasal bone fractures have been rec-  ognized for a long time, the fracture of ethmoids was high-  lighted by Dawson and Fordyce in 1953. Converse and Smith  in 1963 identified the involvement of medial orbital wall and  termed it as naso-orbital. Stranc was the first to in modern  English literature to adopt the terminology naso-ethmoid.  Epker recognized the present-day terminology of naso-  orbito-ethmoid in 1973, whilst Gruss in 1985 preferred the  term naso-ethmoid-orbital [6].    Rowe and Williams [7] in their classic text highlighted the  complexity of the area and stressed the need for primary  management. Their classification was quite simple,  depending on side involved and association with other  fractures.    Markowitz and Manson (1991) [8] identified the impor-  tance of canthal ligament, and their classification reflected  the need for getting the position of the canthal ligament  either by manipulating the fragment or anchoring the can-  thus directly. Their classification was as follows (Box 58.1):   Type Il Comminuted fracture with intact canthal  attachment in the large fragment (positioning  this fragment helps in securing the canthus in the  right place)   ¢ Burstein type II fracture—involves half of the supe-  rior orbital wall, although it does not involve the  NOE    Markowitz classification of adult NOE fractures does not  take into account the differences in paediatric population  such as:    The most common aetiology of the fracture of NOE complex  is trauma be it road accidents in unprotected individuals,  assaults or fall from height [10].   Initial presentation can be disconcerting for the individual  and bystanders due to profuse nasal bleeding and gross  oedema around the midfacial skeleton. The signs and symp-  toms are given in Box 58.3 (symptoms) and Box 58.4 (signs).    Nasal deformity with crepitus  Epistaxis—blood or mixed with CSF  Depressed nasal bridge  Upturned nasal tip  Rounded medial canthus  Altered palpebral fissure shape  Blockage of nasolacrimal duct  — Accentuation of the nasojugal skin fold  — Formation of obtuse angle at the base of columela with  tension on upper lip  — Lip separation caused due to ruptured tip of nose  Telecanthus  (a) lose of almond shape of palpebral fissure  (b) Transverse shortening of the palpebral aperture  (c) Eyelids become lax  (d) Epicanthal fold become more prominent  (e) Flattening of the bottom of naso-orbital valley  (f) Obliteration of the caruncle  (g) Diminished tension of canthal ligament    From the point of view of the examining clinician,  Advanced Trauma Life Support (ATLS) protocols take pre-  cedence however gross the presenting scenario is (Refer  Chap. 48 of this book). Once primary survey is completed  and the patient cleared for secondary survey, definitive clini-  cal examination starts. It is also imperative to rule out under-  lying injuries to the head/brain, ophthalmologic or associated  structures prior to comprehensive maxillofacial assessment.    ¢ Depressed nasal bridge (with or without upturned nasal  tip) is a result of the loss of bony morphology (Fig. 58.3a,  b). When the medial canthal ligament attachment is lost,  the manifestations include loss of contour of palpebral fis-  sure with rounded medial canthal region. The almond  shape of the palpebral fissure is lost and becomes larger,  and Bowstring test becomes positive (Fig. 58.4).   ¢ Traumatic telecanthus is a direct indicator of the MCL  disruption or widening of the fragments. When there is an  intercanthal distance of 35 mm or more, then it may be an  indication of the fragment with MCL being displaced.  Direct physical examination is useful in identifying the  collapsed complex.    Normal values are 32-33 mm for females and 33-34 mm for  males. The rule of thirds can be applied whilst evaluating  NOE fractures. Normally ICD equals the palpebral fissure  width. However, in NOE fractures, increased ICD is found,  called telecanthus (Fig. 58.5).   Telecanthus deformity is characteristic; the lateral dis-  placement of MCT leads to rounding of the medial palpebral  fissure, widening of the NOE region and transverse shorten-  ing of the palpebral aperture.    ¢ Care should be taken to rule out CSF leak and also dam-  age to the nasolacrimal duct. However the latter is diffi-  cult to assess primarily in some of the cases and may  become apparent much later. Clear discharge from the  nose or watery bloody discharge should arouse a high  index of suspicion necessitating further biochemical  investigations to differentiate CSF from nasal discharge.  Glucose content is more in CSF, but assessment of Tau  protein (beta 2 Transferrin) is the confirmatory diagnos-  tic factor. Thorough neurologic and ophthalmologic  assessment is also essential. In the acute setting, clinical  examination is challenging due to the discomfort and    Fig. 58.3 (a, b) Depressed, widened nasal complex with upturned tip  of the nose    always may be inadequate [11, 12], and hence radiologi-  cal investigations are mandatory. The diagnosis and  understanding of the fractures has evolved over the last  century with the advent of CT imaging. CT scan imaging  in all planes is the norm in these fractures and helps in  ruling injuries to the adjacent structures as well as assess-    ing the extent and nature of displacement of NOE com-  plex injuries.   High-resolution CT scan images in all planes (axial, cor-  onal (Fig. 58.6a—d)) help to identify and assess the frac-  ture pattern accurately. Thin sections (0.6 mm) not only  help in better evaluation but also facilitate surgical plan-  ning or fabrication of models if required. The CT scans  will be mandatory anyway to assess the head injury sta-  tus in such cases, and these images can be a part of the  head injury screening imaging. Communicating with the  radiology department of the importance of such images  will ensure that the required sections being done at the  same instance of head injury assessment scans thus  avoiding repeat scans. The axial sections show if there is  disruption of the nasal complex or there is splaying of the  ethmoid complex. The coronal sections depicts the dis-  placement in the mediolateral aspect (thus the status of  the fragment with the MCL), whilst the sagittal sections    @Association of Oral and Maxillofacial Surgeons of India  Fig. 58.6 (a—d) Axial and coronal CT scan images of NOE fracture    depict the displacement in the anteroposterior (AP) Such images are good to plan the surgical management,  aspect (depression). discuss with the assistants the treatment goals and also  e 3D reconstructed images show the gross morphologic sta- explain to the patient the nature of the injury and pro-    tus and are as accurate as the thinness of the sections. posed treatment plan as part of informed consent.    NOE fracture is positive if mobility of the medial canthal  tendon is appreciated.  It is revealed by a Bowstring or a bimanual test.    ¢ Bowstring Test:  When the eyelid is pulled laterally, a lack of resistance or  detection of movement of the underlying bone at the ten-  don area is indicative of a fracture.   ¢ Bimanual Test:  An instrument is placed in the nose and pushed laterally.  Instability and crepitation felt at the tendon area suggests  NOE fracture.    The initial presentation of such patients occasionally may be  dramatic due to profuse epistaxis which may exacerbate in  someone lying down. Keeping patients sitting up with packs  in the anterior nostril might help reduce the bleed. Persistent  profuse bleed may necessitate intubation to secure the air-  way and packs in both anterior and posterior nasal passages  to help prevent aspiration.   The patient once stabilized, and fit to undergo surgery  will need a discussion with the anaesthesiologist about  options of intubation. Fractures not involving occlusion can  be managed by oral intubation, whilst if involving occlusion  then options like submental intubation or even tracheostomy  of the patient requires prolonged ventilation or due to have  further surgical procedures (as in poly trauma patients).   The presence of CSF leak might pose a tricky problem.  Instances of CSF leak are higher whenever there is  pneumocephalus. Hence in such instances, an approach  combined with neurosurgical team may be mandatory, whilst  involvement of an ophthalmologist is mandatory when there  is involvement of lacrimal drainage system or lid adnexa.  The treatment goals of NOE are shown in Box 58.5.   Restoring nasal dorsal height with adequate nasofrontal angle  Re-establishing the MCL attachment    Conventionally the nasal complex was treated with closed  reduction till Adam et al. [6] reported on the importance of  nasal wiring. The importance of involving the medial canthal  region in the treatment plan was initiated by Converse and  Smith in 1963 [6]. They emphasized the importance of manip-  ulating the segment with the MCL, forward positioning the  fragment and trans nasal wiring over a perforated plate.   The case for open reduction and internal fixation (ORIF)  was highlighted by Dingman and Natvig [13]. They reported  superior results have been achieved in the more serious inju-  ries (with minimum of effort and with the greatest degree of  comfort to the patient) by open reduction with direct fixation.  The need and feasibility of identifying MCL and anchoring it  across to the other side was described by Mustarde in 1964  [14]. The need for primarily bone grafting when there is severe  comminution of the nasal dorsum rendering primary reduction  incomplete and also help achieve single-stage reconstruction  was highlighted by Cruse [15] and Gruss [16].   Reduction of the nasal complex may be done with  Walsham’s forceps to realign the deviated/displaced com-  plex. The collapsed complex may be out-fractured, and com-  plex opened out may need to be in-fractured. The depressed  complex may be elevated into position by the septal forceps  (Ash’s). However in displaced or comminuted scenarios,  closed reduction isn’t optimal. Hence trans nasal wiring may  be needed to keep the splayed segments well reduced and  minimize telecanthus. In the absence of gross comminution,  closed reduction and trans nasal wiring has been proved  quite useful and adequate to achieve optimal results as advo-  cated by some authors especially in patients with associated  maxillary fractures [17].   2. Glabella approach—a horizontal skin incision over the  glabella region (Fig. 58.8)   4. Butterfly incision (combination of Gullwing and open sky  incision) (Fig. 58.10)    Ed Ellis et al. [11] reported on having a sequential plan to  proceed with the surgical sequence. They emphasized on  adequate exposure for identification of the bone fragment  with the MCL tendon, realigning the medial rim and cantho-  pexy if required. The nasal dorsum reconstruction is planned  at the end.    According to them pre-treatment photographs are very  important in getting good results, and deformity should be  overtreated than undertreated because secondary deformity  which occurs is difficult to treat.    Fig. 58.10 Butterfly incision (combination of Gullwing and open sky  incision)   e Step 8: Soft tissue readaptation (nasal splint, trans  nasal bolsters, silicone sheeting)    tioning and hence may need trans nasal wiring as well to  help with MCL positioning [6, 13]. Using a K wire driver  or an awl will help pass a trans nasal wire across the nasal  complex and help narrow the area by bringing the sides  together. To help achieve adequate narrowing and restore    the canthal distance, the entry area on the affected site  should be just superior and posterior to the posterior lacri-  mal crest to which the posterior limb of the ligament is  attached. The wire entry point anterior to the area can result  in widening of the telecanthus as the posterior aspect flares  laterally.   As long as a large fragment with MCL attachment is iden-  tifiable, open reduction and fixation of the fragment can help  in achieving our objectives. Using very low profile titantum  plates (1.1-1.3 mm depending on the system used) helps  achieve adequate fixation. Rigid fixation needs exposure of a  stable area to help achieve the same and may necessitate  exposing the glabella or frontal bone superior to it for ade-  quate results. Realignment of the fragments and fixation will  help in achieving better results in cases of fracture having  multiple fragments and reconstruction with bone graft wher-  ever required (Fig. 58.13 a, b).    58.5.2 Trans Nasal Canthopexy  The objectives of trans nasal canthopexy are:    ¢ To medialize the central fragment  ¢ To position the tendon posterior and superior to posterior  lacrimal crest that would give an ideal vector.    The commonly used methods are the trans nasal wiring  (Fig. 58.14) or using a canthal barb. The identified ligament  edges are either anchored with a suture (size 2—0 prolene) or  a wire (26 gauge) and guided to the opposite side. The entry  point is posterior and superior to lacrimal crest to ensure  adequate positioning. One way to help achieve this is to  adapt a plate in medial aspect extending from lateral nose  onto the medial wall extending just beyond the lacrimal crest  (Fig. 58.15).   The wire or suture anchoring the MCL is passed through  a hole of the plate just beyond the lacrimal crest brought to    Fig. 58.13 (a) Alignment and fixation of stable fragments. (b) Bone  grafting of the dorsum of nose    the opposite side and secured around a screw in the fore-  head adjacent to the midline or a plate to prevent the wire  cutting through the bone. Special barbed wires have been  advocated by certain authors to engage the MCL and anchor  it to help with medial canthopexy with small incisions  around the medial canthus. These help especially when  there is medial canthal disruption without bony disruption  [18, 19].   Figure 58.16 shows a clinical case where the MCL has be  anchored to the holes of the plate on either sides (arrows)  with SS wires.   Paediatric injuries of the naso-maxillary complex are gen-  erally under treated, but they need similar management pro-  tocols like that of an adult to achieve optimal results [20].  The use of resorbable implants will be of prudence in the  paediatric patients [3].    Fig. 58.15 Use of plate to guide MCL reattachment (note the MCL  fixed to plate with a wire, the red lines denote the fractured bones)    Post-operative aesthetic assessments of outcomes done  for the management options comparing the canthal position  and nasofrontal angle measurements have indicated that  bone grafting may result in obtunded nasofrontal angle as  compared to ORIF. Closed reduction of the complex has  resulted in under projection of the nasal bridge region [20].    A post-operative nasal bolster splint is very important after  ORIF or NOE fractures. It plays the following functions:    Fig. 58.16 shows a clinical case where the MCL has been anchored to  the holes of the plate (blue arrow) on either sides with SS wires (yellow  arrow)    Redrapes soft tissues to underlying skeletal framework  and prevents pseudo telecanthus (increase in intercanthal  distance, in spite of accurate reduction and fixation of facture  fragments. This occurs due to non-adaptation of soft tissues  to the underlying NOE complex, with resultant fibrosis of  tissues). Bolster splints may cause skin necrosis if used inap-  propriately. After reduction and fixation of NOE, nasal pack-  ing has been done with ribbon gauge soaked in paraffin/  flavine emulsion or bismuth iodoform paraffin paste (BIPP).  Over packing should be avoided. Sometimes it obstructs the  airway and a potential source of infection and required  removal after 72 h postsurgery.    The average distance between the medial canthus should  be approximately 1/3rd (33%) of the distance between lateral  canthus. The distance from the lateral canthus of the eye to  cornea and cornea to nasofrontal junction will be compared,  and they should be in 1:1 relationship. The ideal naso-orbital  angle is approximately 115—130°. All the three parameters    should be checked post-operatively to assess the surgical  results (Figs. 58.17, 58.18, and 58.19).    Inadequate assessment and treatment planning may result in  incomplete management of the NOE complex resulting in  secondary deformity which can aesthetically inadequate.  Deformities of the NOE are quite easily noticeable compared  to those in other regions, and hence appropriate management  helps achieve good results. The aesthetic issues like persis-  tent telecanthus or depressed nasal bridge are difficult to cor-  rect secondarily with suboptimal results. Hence the first time  is the best time to address the central nasal component [21,    22]. Apart from aesthetic complications, functional issues  like epiphora due to nasolacrimal duct injury or obstruction  may manifest which may need stenting [23] or dacryocysto-  rhinostomy (creating a osteum in the lateral nasal wall adja-  cent to the lacrimal sac along with stenting) to establish  patency. Involvement of the medial wall may result in diplo-  pia [24] which if not addressed adequately may persist.  Another important issue overlooked is anosmia, but if it  should occur, recovery is unpredictable, and prior discussion  with patients is better. In cases with concomitant brain inju-  ries or CSF leak, risk of associated sequelae is present, and a  multidisciplinary approach helps. Though improperly placed  trans nasal wires may occlude/impede the lacrimal drainage  apparatus, it remains a popular modality to help treat these  fractures [25, 26].    Fractures of the frontal sinus are frequently associated with  orbital, NOE, nasal and anterior cranial fossa injury. Frontal  sinus is most frequently damaged as a result of high velocity  motor vehicle accidents. 70% of frontal sinus fractures were  due to automobile accidents and 20% due to assaults.  Proximity of sinus to the brain makes untreated disease in  this area potentially fatal. Inappropriate treatment of frontal  sinus fracture can lead to mucocele formation, recurrent  sinusitis, osteomyelitis of frontal bone, brain abscess or  thrombosis of cavernous sinus, encephalitis, etc. [27].    Frontal sinuses are two asymmetric sinuses separated by a  thin bony septal plate. The average dimensions of frontal  sinus are as follows [28]:    ¢ Height: 32 mm  ¢ Width: 26 mm  ¢ Depth: 17 mm  ¢ Surface Area: 720 mm?    The frontal sinus is an air-filled cavity lined by pseu-  dostratified ciliated columnar epithelium encased in  bone. It becomes visible radiographically at the age of 6  years. The posterior table is thinner than the anterior  table. The posterior table separates the sinus from dura of  frontal lobe. Anterior table is covered by a soft tissue  layer of frontalis muscle, orbicularis oculi muscle, supra-  orbital and supratrochlear nerves, vessels and _ skin.  Posteriorly, the floor of the frontal sinus consists of  orbital plate of frontal bone. Anteriorly, the floor of the  sinus overlies the anterior ethmoidal sinus and nasal cav-  ity. The frontonasal drainage area of the sinus originates  from the posteromedial part of sinus floor. The frontal  sinus drains through the frontonasal ducts into the middle  meatus of the nasal cavity or directly through the ostia  into the nasal cavity.    The diagnosis of the frontal sinus fracture based on the  proper history and physical examination of the patient which  includes inspection and palpation of the affected area.    For an accurate diagnosis of frontal sinus fracture, a CT scan  (Fig. 58.20a, b) in different views must be examined [30].    1. Axial view: It reveals location, severity and degree of  comminution of anterior and posterior table fractures.    Fig. 58.20 (a, b) 3D CT and axial CT image with frontal sinus  fracture    2. Coronal view: It reveals frontal sinus floor and orbital  roof fractures.  . Sagittal view: It assesses frontonasal duct.  4. Submentovertex view and lateral view: It visualizes ante-  rior and posterior tables.    ¢ Type I: Anterior Table Fracture  — Isolated to anterior table  — Accompanied by supraorbital rim fracture  — Accompanied by naso-ethmoid complex fracture  ¢ Type II: Anterior and Posterior Table Fractures  — Itisa linear fracture either on transverse direction or in  vertical direction  © Type III: Comminuted Fractures  — Isolated to both tables  — Accompanied by naso-ethmoid complex fracture    ¢ Type I: Anterior Table Fracture  — Isolated to anterior table  — Accompanied by supraorbital rim fracture  — Accompanied by naso-ethmoid complex fracture  ¢ Type II: Anterior and Posterior Table Fractures  — A linear fracture either on transverse direction or in  vertical direction  — Comminuted fracture either isolated to both tables or  accompanied by naso-ethmoid complex fracture  ¢ Type III: Posterior Table Fracture  ¢ Type IV: Through and Through Frontal Sinus Fracture    2. Butterfly incision (Fig. 58.10)  3. Gullwing or eyeglass incision (Fig. 58.21)   e To separate the frontonasal duct from frontal sinus  by obstructing the duct   ¢ To eliminate a functional sinus, sinus mucosa is  removed, and sinus is obliterated    4. Bicoronal approach (Fig. 58.9): Khan et al. in 2018 [34]  suggests sterile surgical glove tourniquet intraoperatively  to get the haemorrhage control and blood less surgical  field in elevation of bicoronal flap for the surgical man-  agement of frontal sinus fracture.   2. To avoid long-term complications such as frontal sinus-  itis, meningitis and brain abscess formation    e Simple greenstick or undisplaced fracture does not require  surgical intervention.   e Indepressed anterior wall fracture, frontal sinus explored,  careful irrigation carried out, fragments reduced and sta-  bilize by internal fixation. In posterior wall fracture with-  out CSF leak or pneumoencephalus, reconstruction of  only anterior wall is done.    Other than surgical intervention, antibiotics, sinus decon-  gestants and analgesics are prescribed to keep the frontona-  sal duct patent and to prevent infection.   Rai et al. [39] suggested bone mapping/sketching in man-  agement of anterior table frontal sinus fracture with great  success. To get good post-operative contour, each fracture  fragment is to be placed at the original position after debride-  ment of the sinus. For the same purpose, numbers have to be  given to the fracture fragments on a plane paper (sterile glove  covering paper) or green sheet (Fig. 58.22a—c).    ments, they advocated use of custom made latex glove bal-  loon to be inserted into the frontal sinus then expanded and  maintained for 3 weeks. It avoid use of coronal incision is the  advantage of endoscopic reduction. It should be avoided in  severe comminuted fractures, displaced posterior table frac-  ture with evidence of dura tear, associated orbital roof blow  in fracture and extensive skull bone fractures.    Patients with displaced and comminuted posterior wall com-  bined with or without anterior wall require the support of a  neurosurgeon because of dural and intracranial lesions. To  get the good exposure, bifrontal craniotomy is indicated to  eliminate the posterior wall.   To widen the neurosurgical access to the anterior floor of  the cranium, the supraorbital bandeau will be temporarily  removed. The sinus mucosa carefully removed with bur, and  sinus is cranialized, and then repair of the dura will be car-  ried out: Calvarial bone graft used to obliterate the nasofron-  tal duct and bone powder can be used to cover the remaining  dead space. Anterior table can be stabilized with bone plates  and screws. Bone defect will be treated with calvarial bone  graft or titanium mesh. With patent duct and no concurrent  dural tears or brain injury exist, any amount of posterior  table displacement is inconsequential and managed by  observation.    The damage to the nasofrontal duct and frontal sinus obstruc-  tion increases the risk of mucocele formation and inflamma-  tory complications post-operatively. Obliteration of the duct  is indicated in such situation. The muscle, temporalis fascia,  bone chips, etc. are the materials used commonly to obstruct  the duct.    — _ a a  @©Association of Oral and Maxillofacial Surgeons of India   3. Paresthesia of supraorbital nerve 3. Late frontal sinusitis  4. Frontal sinusitis 4. Brain abscess    It is another technique to minimize the dead space in sinus. It  involves removing posterior table thus permitting brain to  expand into frontal sinus resulting in confluence between  sinus cavity and anterior cranial fossa. It is done in cases  with CSF leak and neurological injury due to displaced pos-  terior table fracture. To isolate the splanchnocranium from  the frontal sinus, a pericranial flap is used.    Actual or suspected fractures involving the frontonasal  duct are an indication to remove the outer table, so the  duct can be inspected.   If outer table is comminuted and a bony segment over  1.5 cm in missing, a bone graft should be harvested to  restore the outer table contour.   The most common treatment for outer table fracture with  injury to duct without inner table fracture is obliteration  of frontal sinus to seal the frontonasal duct to prevent  nasal infection.   Adipose tissue from abdomen is used to fill the dead  space of frontal sinus because of its resistance to infec-    tion, slow resorption rate, and it is gradually replaced by  the fibrous tissue.    The management of NOE and frontal sinus fracture is always  a challenging task .The proper handling of MCL and naso-  frontal duct is mandatory to get good post-operative results.  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Transnasal fixation of NOE fracture: mini-  mally invasive approach. J Maxillofac Oral Surg. 2012;11(1):34-7.  Timoney PJ, Sokol JA, Hauck MJ, Lee HB, Nunery  WR. Transcutaneous medial canthal tendon incision to the medial  orbit. Ophthal Plast Reconstr Surg. 2012;28:140-4.   Goldenberg DC, Bastos EO, Alonso N, Friedhofer H, Ferreira  MC. The role of micro-anchor devices in medial canthopexy. Ann  Plast Surg. 2008;61:47-51.   Pawar SS, Rhee JS. Frontal sinus and naso-orbital-ethmoid frac-  tures. JAMA Facial Plast Surg. 2014;16:284-9.   Herford AS, Ying T, Brown B. Outcomes of severely comminuted  (type III) nasoorbitoethmoid fractures. J Oral Maxillofac Surg.  2005;63:1266-77.   Potter JK, Muzaffar AR, Ellis E, Rohrich RJ, Hackney FL. Aesthetic  management of the nasal component of naso-orbital ethmoid frac-  tures. Plast Reconstr Surg. 2006;117(1):10e—8e.   Vora NM, Fedok FG. Management of the central nasal support  complex in naso-orbital ethmoid fractures. Facial Plast Surg.  2000;16(2):181-91.   Becelli R, Renzi G, Mannino G, Cerulli G, Iannetti G. Posttraumatic  obstruction of lacrimal pathways: a retrospective analysis of  58 consecutive naso-orbitoethmoid fractures. J Craniofac Surg.  2004;15:29-33.   Wei J-J, Tang Z-L, Liu L, Liao X-J, Yu Y-B, Jing W. The man-  agement of naso-orbital-ethmoid (NOE) fractures. Chinese J  Traumatol. 2015;18:296-301.   Bell RB, Dierks EJ, Homer L, Potter BE. Management of cerebro-  spinal fluid leak associated with craniomaxillofacial trauma. J Oral  Maxillofac Surg. 2004;62:676-84.   Gerbino G, Roccia F, Benech A, Caldarelli C. Analysis of 158 fron-  tal sinus fractures: current surgical management and complications.  J Craniomaxillofac Surg. 2000;28:133-139.   Haug RH, Cunningham LL. Management of fractures of the frontal  bone and frontal sinus, selected Readings. Oral and Maxillofacial  Surgery. 2002;10(6):1-32.   Wallis A, Donald PJ. Frontal sinus fractures: a review of 72 cases.  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Cole P, Kaufman Y, Momoh A, et al. Techniques in frontal sinus    fracture repair. Plast Reconstr Surg. 2009;123(5):1578-9.  Weathers WM, Wolfswinkel EM, Hatef DA, Lee EI, Brown  RH, Hollier LH Jr. Frontal sinus fractures: a conservative shift.  Craniomaxillofac Trauma Reconstr. 2013;6(3): 155-60.    Rai A, et al. “Bone mapping/sketching” in management of  anterior table frontal sinus fracture. J Maxillofac Oral Surg.  2017;16(1):127-30.   Yoo MH, et al. Endoscopic transnasal reduction of an anterior table  frontal sinus fracture: technical note. Int Journal Oral Maxfac Surg.  2008;37:573-5.   Freeman JL, Winston KR. Breach of posterior wall of frontal sinus:  management with preservation of the sinus. World Neurosurg.  2015;83(6): 1080-9.   Rohrich RJ, Hollier L. The role of the nasofrontal duct in fron-  tal sinus fracture management. J Craniomaxillofac Trauma.  1996;2:31—40.   Mickel TJ, Rohrich RJ, Robinson JB Jr. Frontal sinus oblitera-  tion: a comparison of fat, muscle, bone, and spontaneous osteo-   Scholsem M, Scholtes F, Collignon F, et al. Surgical manage-  ment of anterior cranial base fractures with cerebrospinal fluid  fistulae: a single institution experience. Neurosurgery. 2008;62:  463-71.   Pollock R, Hill J, Davenport D, et al. Cranialization in a cohort of  154 consecutive patients with frontal sinus fractures (1987-2007):  review and update of a compel- ling procedure in the selected  patient. Ann Plast Surg. 2013;71(1):54-9.   Guy WM, Brissett AE. Contemporary management of trau-  matic fractures of the frontal sinus. Otolaryngol Clin North Am.  2013;46(5):733-48.    Open Access This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.  org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropri-  ate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.   The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in  a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.    59.1 Introduction  Gunshot injuries to the maxillofacial region in particular  present a challenging situation for the facial reconstructive  surgeon. These injuries are relatively rare and hence the true  incidence is unknown [1]. Feature common to most maxil-  lofacial gunshot injuries is extensive tissue destruction. The  degree of tissue loss, depth of the injury, associated necrosis,  and concomitant central nervous system (CNS) injuries may  not be apparent at initial presentation [2]. Comprehensive  management of such wounds is often challenging because of  its heterogeneous nature, composite 3D tissue destruction,  and complex structural and functional anatomy of the face.  In contrast to blunt facial trauma, the literature on the  management of ballistic facial injury is relatively scarce [1].  The management strategies for patients with facial gunshot  wounds are almost as diverse as the case presentation itself.  While there has been a gradual shift from conservative  delayed operative repair to an early aggressive one-stage  management approach, the controversies surrounding the  timing and extent of intervention have not yet ceased to exist.  Such an ongoing debate is largely due to the fact that the  majority of treatment outcomes of gunshot facial injuries  continue to be unsatisfactory regardless of treatment meth-  odology adopted. On the other hand, new principles have  evolved including the early definitive repair of hard tissues  with precise anatomic rigid fixation using bone grafts and  definitive soft tissue management with local or vascular flaps  allowing for early rehabilitation of patients to their pre-  traumatic appearance. This paradigm shift away from  delayed to a more immediate definitive reconstruction has  been predominantly due to the widespread use of free tissue    Lt Col R. Sharma   Department of Oral and Maxillofacial Surgery,  11 Corps Dental Unit, Jalandhar Cantt, India    Maj A. Jose  Department of Oral and Maxillofacial Surgery, ADC R&R,  New Delhi, India    © The Association of Oral and Maxillofacial Surgeons of India 2021    transfer, diagnostic computed tomography (CT) scan, and  deeper understanding about zone of injury in such cases [3].    This review describes the current management strategies,  damage control surgery, and basic protocols employed in the  management of high-velocity ballistic injuries to the face.    Traditionally gunshot injuries have been classified as pene-  trating, perforated, or avulsive [7]. As the gamut of injuries  continues to evolve, the severity and magnitude of facial bal-  listic wounds demand an expanded classification and can be  appropriately classified based on the wounding effects and  terminal location of projectile as:    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1-15-1346-6_59    Penetrating injuries are caused when a low-velocity pro-  jectile pierces the tissues without making an exit wound  (Fig. 59.1).   On the other hand, perforating injuries are distinguished  by the presence of a definite exit wound in addition to the  entry wound (Figs. 59.2 and 59.3). The exit wounds are often  larger with ragged or stellate margins. Avulsive injuries are  basically penetrating injuries, characterized by an acute loss  and destruction of tissue as a consequence of the passage of  the projectile within and out of the body (Fig. 59.4). Blast    Fig. 59.2 Perforating injury caused by 7.62 x 39 mm AK-47 rifle.  Note the effects of high-energy bullet impact and explosive effects of  cavitation on soft tissues resulting in stellate wound margins at the exit    Fig. 59.3 Avulsive injury of midface caused by a short-range high-  velocity impact. The hallmark of high-velocity injuries are comminuted  fractures of the facial skeleton with avulsion of soft tissues    SS a s  ©Association of Oral and Maxillofacial Surgeons of India    injuries are the result of direct or indirect exposure to an  explosion caused by military weapons or explosive devises  (Fig. 59.5). “Chop off” injuries represent wounds with exten-  sive hard and soft tissue loss as a consequence of high-  velocity close-range gunshots [8]. In all these varieties of  injuries, the tissue damage is directly proportional to the    kinetic energy transferred by the bullet, time taken for the  energy transfer, and area over which the energy is trans-  ferred. Hence, the type and variant of injury have significant  implications in management.   Apart from this conventional nomenclature, various other  classifications have been used for categorizing penetrating    Fig. 59.5 (a, b, c) Blast injury caused by propagation of shock waves from the projectile. Soft tissue injury is minimal in such cases with severe    facial injuries; however, its application in clinical scenario is  debatable. Similarly, many authors have developed an algo-  rithm for the workup of ballistic wound based on the location  of entry wound. Despite having limited application, no sig-  nificant correlation has been found between site of entrance  wound and therapeutic outcome of gunshot wounds [9].    Initial management of gunshot wounds is based on the  advanced trauma and life support protocols (also refer Chap.  48 of this book). Gibbons and Breeze [10] have elaborated  the modified military protocols pertaining specifically to  combat-related ballistic facial injuries. These include emer-  gency management procedures that followed the CABC  (catastrophic hemorrhage, airway, breathing, circulation)  protocol proposed by Hodgetts et al. [11] which focused the  need to control catastrophic bleeding as a priority over air-  way complications in a polytrauma patient. In a parallel  manner, initial evaluation and damage control maxillofacial  surgery should commence within the golden hour for effec-  tive patient management. Damage control surgery may be  perceived as an immediate assessment of life-threatening  injuries and addressing them promptly by means of early  life-saving resuscitation and surgeries [12]. It is not regarded  as a separate entity; it is seen as an essential, initial compo-  nent in the management of any severely injured patient. In  order to clear confusion clouding this highly debated area, a  proposed set of damage control procedures that can be  applied to ballistic maxillofacial injuries involving the max-  illofacial region is given (Table 59.1).   Fortunately, the mortality rate directly attributable to  maxillofacial firearms injuries is as low as 2—3% and pre-    dominantly due to a compromised airway [10]. Airway com-  promise is a serious consequence of all gunshot injuries to  the face, and it can be due to a direct or an indirect injury to  the airway. Injury to tissues and resultant edema in the vicin-  ity of the air passages invariably handicaps the airway indi-  rectly. Additionally, loss of muscle attachments and fractures  of the anterior mandible significantly debilitates the airways.  Manual repositioning of the fractured segments of mandible  and base of tongue are the fundamental measures to be exe-  cuted to prevent posterior airway collapse. While nasopha-  ryngeal and oropharyngeal airways afford interim relief,  endotracheal intubation is the established approach in emer-  gency condition. This however presents a challenge on  account of the edema, bleeding, and avulsed soft tissues that  may possibly block the airway [13].   In the author’s experience, a vast majority of maxillofa-  cial gunshot wounds require surgical tracheostomy. The  probability of concomitant intracranial injuries with low  Glasgow Coma Scale (GCS) is also high in such patients  [14]. Since most patients in this category require prolonged  intubation and most gunshot wounds to the face require  multi-phased surgical approach, the authors view surgical  tracheostomy as having distinct advantage over other meth-  ods. Management of hemorrhage and its allied complica-  tions are well known in maxillofacial injuries as emphasized  by previous writers on war surgery, yet it needs a descrip-  tive analysis owing to the fatality it can cause. Hemorrhage  is an inevitable consequence of all gunshot injuries to the  face. Management of bleeding is an important aspect of  damage control surgery, and adequate hemodynamic resus-  citation is essential for the early physiological recovery of  the victim [15].   Bleeding from high-energy ballistic injuries is practi-  cally impossible to control by external pressure tamponade  due to the presence of bony structures and the inherently  vulnerable condition of fragile anatomic structures like the  eyes, brain, and airway seen in such injuries. In open injury  scenario, hemorrhage can be easily managed by meticu-  lous examination to recognize all the bleeding vessels fol-  lowed by their ligation. Closed injuries necessitate balloon  tamponade with Foley catheter (Fig. 59.5) to control bleed-  ing. If bleeding is not controlled by the usual techniques,  external carotid ligation or selective embolization method  is used, which is by far the most predictable method to  control bleeding from external carotid artery and its tribu-  taries [13, 16].    Table 59.1 Algorithm in the treatment of Gun Shot Wounds (GSW)    Once airway is secured and bleeding is controlled, attention  should be directed toward radiological assessment of the  injury. Depending on the severity of injury a plain X-ray, CT  scan and CT angiography can be requested [15]. The extent  of injury, degree of hard tissue fragmentation, location of  metallic splinters, damage to C-spine, and any occult brain  injuries can be easily delineated with the help of a CT scan.  Similarly, involvement of great vessels, any concealed bleed-  ing, and flow dynamics of vessels suitable for microvascular  reconstruction can be studied using CT angiogram. Apart    from the damage characteristics of the wound, another  crucial factor which needs to be assessed during radiological  examination is the status of C-spine.   Any injury of such magnitude enough to fracture the  facial skeleton can invariably cause an occult C-spine injury.  The incidence of C-spine injuries varies from 8 to 11% in all  maxillofacial traumas [17]. Hence, potential cervical spine  injury should be always considered unless proven otherwise  clinically or radiologically. It is pertinent to immobilize the  cervical spine to prevent further damage especially in uncon-  scious patient (Fig. 59.6). However, substantial evidence is  still lacking about the safety and efficacy of cervical collars    used in such injuries. Moreover, placement of rigid collars  interferes during airway management, central line place-  ment, and definitive repair of facial injuries [13].    The prime goal in the management of facial gunshot wounds  is to rehabilitate the patient to pre-injury function and aes-  thetics. However, it is not always easy to get a flawless post-  operative outcome with one particular treatment modality or  a particular surgical technique. Hence, the treatment should  be timed and tailored depending upon the type and severity  of the injury, amount of tissue loss, general health status of  the patient, surgeon’s expertise, and availability of resources.  Before initiating any treatment procedures, a thorough  assessment of the wound by a multidisciplinary team is  imperative as gunshot injury cases are seldom comparable. A  comprehensive evaluation and discussion by a diverse panel  gives the surgeon valuable perspectives which in turn has a  positive impact on the final outcome.    Modern high-velocity firearms transfer heavy cavitation  energy inside tissues causing physiological and morphologi-  cal alterations resulting in hemorrhage, thrombosis, and  necrosis [18]. The tissue response toward the high-velocity  projectile varies with the type of tissues and elastic deforma-  tion it can sustain. The dermis is viscoelastic, and injuries  will result in abrasion, traumatic tattooing, and contusion  particularly in close-range shots. Muscle tissues can with-  stand elastic deformation up to four times the size of the pro-  jectile, but at a cellular level, it may undergo significant  necrosis, devitalization, and denaturation rendering the  microenvironment favorable for bacterial multiplication  [19]. The injuries to neurovascular bundles behave similar to  muscles, thereby causing tearing, shearing, and rupture of  blood vessels. At microscopic level, all the three layers of  blood vessels get affected resulting in the formation of  thrombus, inflammation, and persistent spasm [20]. Cortical  bone on the other hand is crystalline in consistency; there-  fore, penetrating injury causes fragmentation of bone with  formation of multiple secondary projectiles. Conventional  management of firearm injuries involves initial wound  debridement, wound toilet, adequate soft tissue closure, and  administration of antibiotics followed by delayed repair of  deformities [4]. However, with the advent of vascular flaps  and new reconstruction methods, there has been a colossal  shift in the management of such injuries to a more definitive  early single-stage repair [21].    The management commences with meticulous debride-  ment of wounds to the point of active surgical bleeding. This  strategy is particularly important in case of crushed and con-  taminated wounds wherein the active surgical bleeding  encourages the formation of a healthy granulation tissue  [18]. Furthermore, it also improves adequate microcircula-  tion at wound margins, thereby promoting rapid healing and  tissue resistance to infection. A serial debridement with judi-  cious excision of the necrotic and non-contractile muscle tis-  sues is done to achieve a wound with non-contaminated  healthy margins [22].   After generous tissue excision, debridement should be  assisted with soft scrubbing brushes and copious irrigation.  Removal of deeply embedded splinters or metallic foreign bod-  ies is controversial regarding any particular clinical benefits it  offers [10]. The wound debridement should be prompt, and any  delay (6-12 h) further complicates the wound management by  progressive tissue necrosis. The development of progressive  necrosis is a salient feature of gunshot wounds, and contrary to  the popular belief, the tissue necrosis is not directly related to  energy transfer but rather to the depth of tissues destroyed by the  movement of the projectile. Animal studies have shown that  beyond that critical time period, identification of necrotic mar-  gins will be difficult and hence it complicates the debridement  and surgical control of the wound [23].   There are two main areas of conflicts pertaining to  debridement in gunshot wounds. Many authors recommend  immediate careful conservative soft tissue excision followed  by secondary debridement of all tissues with questionable  viability at a later stage [24, 25]. These researchers are of the  view that it is practically impossible to distinguish between  vital and non-vital tissues at initial intervention. On the con-  trary, a few other professionals believe in single-stage radical  debridement on initial intervention [26].   Experimental evidences have shown that the extent of tis-  sue necrosis after gunshot injury is 2 mm and 8 mm from the  wound margins in skin and muscle tissues, respectively. In  bony skeleton, it may extend up to 5 mm from the fracture  line [27]. Thus, there is no convincing evidence to preserve  fragmented bone of | cm or less during debridement even if  it is attached to soft tissues. Similarly, a serial debridement  of such wound is often required to deal with the evolving  pattern of tissue necrosis over a period of 24—36 h. This  allows for early identification of the demarcation zone  between vital and non-vital tissues before reconstructive pro-  cedures are planned. The consensus of radical wound  debridement at initial intervention aims to remove foreign  bodies, necrotic tissues, and microbial contamination as  early as possible. It also minimizes inflammation, prevents  infections, and helps in achieving favorable wound healing.  Any late wound management in our opinion eventually  increases the chances of infection, operating time, toxemia,  and subsequent surgical intervention.    Concomitant injuries to salivary gland ducts and facial  nerve are often encountered during initial debridement. The  ducts and facial nerve are usually tagged with Prolene sutures  for future repair. Most of the ductal injuries can be managed  by cannulation and primary repair or by rerouting it into oral  cavity. Non-salvageable glands should be removed without  hesitation to prevent sialocele, salivary fistula, and compli-  cated wound healing. Damage to facial nerve is mainly by  thermal, avulsion, and stretch injury caused by the cavita-  tion. Preferably the nerve should be repaired within 72 h for  predictable results. Lacerated nerve is repaired primarily by  coaptation or using nerve grafts harvested from greater  auricular nerve. The nerve damage caused by cavitation may  extend as far as 1.8 cm from the bullet track, and that should  be considered during nerve grafting procedure [19]. Any  facial nerve injury anterior to a line connecting mental fora-  men and lateral canthus is generally not repaired as sponta-  neous recovery is very likely in such cases.   Ballistic facial injuries are often compound and contami-  nated with high propensity for infection (class IV wounds).  Contrary to the popular belief, all ballistic injuries are inher-  ently contaminated, and the infection is primarily by the  inoculation of microorganisms carried by the bullet and sec-  ondarily as a result of wound contamination in transit or in  hospital environment. The actual incidence of infection rates  remains elusive and ranges from 7 to 100% of all military  facial injuries [28]. However, a general consensus is lacking  in the timing, choice, and duration of antimicrobial therapy  in combat injuries. Nonetheless the usage of broad-spectrum  antibiotics for 10-14 days which provides cover against  staphylococci, Clostridium perfringens, and Acinetobacter  baumannii is commonly used [14, 29]. The critical level of  bacteria required for initiating an infection reaches peak at  6 h of injury (10° bacteria/gm. of tissue), and studies have  shown that early administration of antibiotics is paramount  and any delay of greater than 6 h renders the treatment inef-  fective [30]. The accepted guidelines for combat-related  injuries recommend administration of short-course, broad-  spectrum antibiotics preferably within 3 h of injury [31]. The  use of antibiotics is an adjunct to scrupulous debridement for  the prevention of infection and should always be considered  in the initial management of ballistic injuries.    Gunshot wounds result in composite 3D defects with involve-  ment of the skin, musculature, facial skeleton, and mucosa.  The various reconstruction methods for wounds of these  natures are prosthetic obturation, non-vascularized grafts with  local tissue advancement, loco-regional flaps, and free flaps  for large composite defects (Also refer Chaps. 86 and 88 of  this book). Before initiating the reconstructive procedure, it  should be kept in mind that the management of such wounds  is often complicated by the ambiguity in prognosis caused by  tissue loss, progressive necrosis, and infection. Therefore most  critical facet while handling avulsive wounds lays in achieving  and maintaining a favorable intraoral wound closure to mini-  mize the chances of wound infection and wound dehiscence  due to oral contamination [32]. It is always crucial to close the  wound primarily because of the high propensity toward scar-  ing and functional debility of wounds that heal secondarily.  Most gunshot wounds can be closed primarily, and delayed  wound closure in maxillofacial region is rarely necessary.  However, two exceptions to this are (1) wounds which are not  possible to debride completely at initial operation and (2)  wounds with questionable vitality of tissues.   Sequencing of primary reconstruction of oro-facial  region should follow an inside-out principle [33]. The inju-  ries of the oropharynx are first addressed by repairing the  musculature and mucosa. This is followed by repair of oral  mucosa, floor of the mouth, and the tongue. The recon-  struction of lips, cheeks, and other extra-oral tissues is per-  formed later after oral cavity has been reconstructed.  Nonetheless if an acceptable intraoral closure is difficult to  achieve, a maxillomandibular fixation is done, and it is pru-  dent to leave the wound to heal secondarily. While select-  ing a reconstructive option, it is important to consider a  treatment plan which reduces the treatment time, patient  morbidity, number of surgical intervention, and hospital  stay [34]. The best possible function and aesthetics are  achieved when debridement and reconstruction of hard and  soft tissues are done at an early stage and the residual soft  tissue deformities are addressed at a later stage with revi-  sion surgeries and local flaps [2]. Extra-oral wounds that  cannot be closed primarily due to excessive tissue loss are  best managed by employing local, regional pedicled flaps  and microvascular flaps.   Use of local flaps and regional flaps at the initial operation  appears to be most favorable as far as aesthetics and function    are concerned (Fig. 59.6a). Motamedi [2] advised early use  of local flaps in patients with gunshot wounds of the face. He  reviewed 30 GSW patients and reported excellent cosmetic  and functional outcomes. However, the disadvantages of  local flaps are that composite defects cannot be addressed  and its availability, limited bulk, and pedicle length. Local  tissue rearrangements and local flaps with nonvascular grafts  like iliac crest, rib, or cranium can be used for small defects.  But large 3D defects and poorly vascularized surrounding  tissues caused by cavitation often preclude the use of bone  grafts with local tissue rearrangements unlike in tumor  reconstruction.   Major avulsive and chop off injuries demand vascularized  bone grafts with skin paddle for their reconstruction.  Composite free tissue transfer is predictable, provides ade-  quate bulk of well-vascularized tissue to fill the dead space,  rehabilitates the buttresses, and reinstates the soft tissue  envelope in a limited period of time [15]. The variables  affecting the selection of flap depend on the type and amount  of tissue loss, location, length of pedicle, donor site injury,  and, certainly, surgeon’s preference. The most commonly  used flaps for facial reconstruction are anterolateral thigh  flap, radial forearm, and fibula with skin paddle [5]. It is  obligatory to reconstruct both bone and soft tissues in com-  posite defects, and without osseous support, soft tissue-only  reconstruction tends to droop over time. After primary heal-  ing, the flap is contoured, subsequently unaesthetic skin  paddle is excised, and local tissue can be re-advanced for  better aesthetic outcomes. Similarly, if adequate vascular-  ized tissue is not used for reconstruction, complications like  scar contracture, bone graft resorption, fistula formation, and  ultimately collapse of facial envelope will result.   It is clear that reconstruction of avulsive facial defects  with free flap should be addressed as early as possible to  prevent soft tissue contracture. Nonetheless, how much grace  period is required before initiating a free flap reconstruction  for optimizing the reconstructive outcomes is still not clear.  High-energy cavitation in soft tissue may temporarily dam-  age the local vasculature and hemodynamics at a distance  from the margin of permanent wound. While planning a  treatment based on microvascular reconstruction, it is imper-  ative to have a conception of the zone of injury in its actual  extent. Animal studies have shown that it is safe to place an  anastomosis 3 cm away from the margin of wound track  [35]. Furthermore, experimental evidences have shown supe-  rior results in integrity and patency of facial vessels anasto-    mosed 3 days after injury than those repaired immediately  after the injury [20]. If it is so, a composite free tissue trans-  fer as a part of immediate reconstruction in avulsive ballistic  injuries should be delayed till 3-4 days. This time period  helps in adequate assessment of the extent of devitalized tis-  sues, formulating a treatment plan based on available  resources and optimizing the results by executing the treat-  ment before the onset of soft tissue fibrosis and when the  blood vessels are devoid of spasm.   Despite several arguments favoring immediate recon-  struction for excellent aesthetic outcomes, it is to be noted  that scar contracture is inevitable irrespective of the timing  of treatment and reconstruction method adopted, although  the frequency is more with delayed treatment [36]. Therefore,  a review to determine the need for secondary corrective pro-  cedures should be conducted in consultation with the inter-  disciplinary team. Scar contracture is usually managed later  by revision surgeries after the maturation of scar. The total  number of revision surgeries required for a free flap is less as  compared to local or regional flaps. The outcomes of revi-  sion surgery depend on the type of flap used, complexity of  the defect, and location of the defect with nasal, orbits, and  lips requiring the highest number of aesthetic refinements  [5]. Similarly other expected soft tissue complications like  trismus, microsomia, and other functional disabilities can be  addressed by fat grafting, coronoidectomy, commissuro-  plasty, and Botox injections [37]. Very often the reconstruc-  tive surgeries of aesthetically prominent regions of the face  like nose and orbits are always suboptimal, and in such cases,  prosthetic rehabilitation can be considered even though not  physiological and patient compliance is less.    In patients without continuity defect, infection and mini-  mal comminution open reduction and internal fixation  (ORIF) is simultaneously done along with debridement at  the initial stage.   Once initial stabilization is ensured, fixation is generally  accomplished by miniplates or reconstruction plates.  However, wounds with limited soft issue coverage require a  different strategy as the granulation tissues may fail to cover  thickness of plate resulting in subsequent plate exposure.  Thus, if adequate soft tissue cover cannot be achieved,  debridement, external pins, and maxillomandibular fixation  (MMF) are the method of choice [33]. Until the introduction  of surgical screws and plates, closed treatment was the  preferred mode of treatment. The treatment ideology was  directed to treat the whole wound as a “bag of bones” using  external fixation or MMF in order to avoid periosteal strip-  ping and devitalization of small fragments of bone. Although  this therapeutic concept is advocated by several authors, who  have reported significantly lesser rates of infection with this  technique when compared with ORIF and plates, the value  approach continues to be underestimated [38].   The advantages of external fixation are manifold. It helps  to prevent bone devascularization, allows for bone regenera-  tion, and also provides adequate support to the comminuted  fracture fragments. Additionally, it also enhances the osteo-  genic potential of the injury site by helping in spontaneous  bone regeneration. This phenomenon is more commonly  seen in young patients due to hypoxia and acidosis-induced  activation of local bone morphogenic proteins (BMPs). The  high-velocity trauma causes extensive damage to adjacent  muscles and periosteum. This damage along with the effects  of local inflammation, hypoxia, and increased carbon diox-  ide concentration activates BMPs resulting in spontaneous  bone formation. The concept and knowledge regarding facial  buttress and its implication in trauma management have  added a new dimension in the functional and aesthetic recon-  struction of the face. As a result, internal fixation using lock-  ing plates has greatly replaced external fixators over a period  of time. It is currently the most widely used technique in  management of GSWs with bone loss and is used if the frac-  ture fragments are large enough to accept screws.   Additionally, bone defects if any should be grafted with  harvested iliac crest, ribs, or cranium depending upon the  size of the defect (Fig. 59.7). However, the infection rates  associated with internal fixation are comparatively higher  as quoted by many authors. The increased rates of infection  associated with ORIF are due to loosening of hardware and  subsequent micromotion at the fracture site and possibly by    contamination by oro-nasal flora. Motammedi [2] reported  that it is almost impossible to achieve occlusion without  arch bars and MMF in majority of gunshot fractures.  Presently ORIF along with arch bars continue to be the  mainstay in the management such patients. With the advent  of new techniques of reconstruction supplemented by inno-  vative plates and screws, vascular grafts and antibiotics  have heralded a paradigm shift in the treatment philosophy.  Current principles clearly favor early definitive reconstruc-  tion of hard tissues with ORIF using rigid fixation supple-  mented by MMF and bone grafts whenever required  (Fig. 59.8).    An area of ongoing debate and controversy in the manage-  ment of gunshot wounds of the face is regarding the timing  of definitive reconstruction [6, 39]. Although previous teach-  ings and practices were in favor of delayed reconstruction,  the more recent studies demonstrate predictable functional  and aesthetic outcomes with immediate definitive recon-  struction [40-42]. Scientific studies suggest carrying out  definitive reconstruction within a time frame of 48 h would  yield the best possible outcome [2].   Advocates of delayed reconstruction believe that the  delay in treatment reduces the probability of infection,  necrosis, and postoperative wound complications exponen-  tially. Additionally delay in treatment reduces the chances of  mortality and morbidity due to infection and progressive tis-  sue necrosis [43, 44]. Any increase in postoperative tempera-  ture, raised leukocyte counts, and other local signs of  infection may invariably cause a failure in flap due to risk of  venous thrombosis. It has also been suggested that the  decreased inflammation and edema aid surgeons to have a  better assessment of the extent of injury, thereby helping in  precise and desired treatment planning which in turn could  lead to a better outcome. Therefore in their opinion, it is pru-  dent to wait before applying any principles of primary recon-  struction until a healthy tissue bed is achieved. On the other  hand, the disadvantages of delayed treatment are increased  treatment time, prolonged hospital stay, increased cost of  treatment, and patient distress caused by psychosocial impact  of disfigurement associated with gunshot injury (Tables 59.2  and 59,3).   Advocates of early primary treatment claim superior  functional and aesthetic outcomes, early restoration of facial  form, and limited hospital stay with early return to normal    Fig. 59.7 (a-d) High-velocity close-range assault rifle injury with  comminution of mandible and soft tissue loss. Managed initially by  non-vascularized graft and later by free fibula osteocutaneous flap    function [4, 14, 45]. These benefits are predominantly due to  the elimination of soft tissue contracture by proper anatomic  coverage of soft tissue at an early stage [21]. Vasconez et al.  [42] compared the infection rates of gunshot wounds that  have been managed by early and late reconstruction in a  series of 33 cases. In their observation, they could not found    reconstruction. External fixator for stabilizing fibula in place. Follow-up  after complete treatment    any significant difference in infection rates between the two  groups. However, the delayed group showed an apparent  increase in the incidence of scar contracture with significant  functional and aesthetic complications. Similarly, several  other studies have also reported excellent clinical outcomes  when immediate reconstruction is carried out [46].    Fig. 59.8 (a—d) High-velocity assault rifle injury to the face with loss of hemimaxilla and mandible along with partial loss of upper lip was done.  Reconstruction of the upper lip by hair-bearing submental island flap. Mandible reconstruction is performed by vascularized fibula    Definitive management of most maxillofacial injuries is  not a surgical emergency, and treatment is often delayed in  polytrauma patients. A standard consensus for delaying  treatment and adopting a staged approach in such cases is  due to the inability of a critically injured patient to undergo    surgical intervention. However, as soon the patient is deemed  to be medically stable, operative intervention targeted toward  managing the facial injuries should be initiated. It is impera-  tive to address the bony and soft tissue injuries soon after the  resolution of edema and before the initiation of fibrosis of   Less scar contracture,  better postoperative  function and aesthetics  Early return to function  and less hospital stay   Proper anatomical  coverage of defect so  chances of infection are  less   The margins of devitalized tissues and  its extent cannot be appreciated during  early repair   Correction of subtle deformities is  difficult and such minor correction  always requires second intervention  Surgeon’s expertise and availability of  resources    Tissue edema immediately following  the injury will hamper the judgment of  surgeon resulting in suboptimal  outcome   Number of hospital stay is  increased with more psychological  burden to the family and patient  due to disfigured face    Correction of defects after the  resolution of edema will give a  clear picture of the defect size  Correction of minor deformities  is possible which may have  been missed during immediate  reconstruction    soft tissues and malunion of fractures. This grace period will  allow the surgeon to have an accurate and swift identification  of subtle deformities for a major single-stage intervention  rather than repeated assault to soft tissues causing fibrosis  and decreased vascularity.   The essential difference in the management of routine  maxillofacial injury and gunshot wounds of the face is the  requirement of a multidisciplinary team for the management  of gunshot wounds. Therefore, a short-term delay or tempo-  rizing such wounds allows time to procure diagnostic images  and study models and lastly for a discussion on inputs from  the medical and surgical team. In general, the formulation of  treatment plan should be based on the general health status  of the patient, availability of resources, surgeon’s expertise,  and patient’s will.   In a vast majority of cases despite the primary manage-  ment approach, a significant number of gunshot injuries are  plagued with residual functional and aesthetic problems.  Hence, a good postoperative outcome is multifactorial and is  the reflection of all the above factors and not just the early  definitive repair. However, a large number of maxillofacial  gunshot wounds can be treated definitively at the time of ini-    The general physical status of the patient, timing of  surgery, extent of composite tissue damage, good sur-  gical techniques, use of appropriate hardwares, antibi-  otics, and proper rehabilitation are the factors which  determine the final outcome and aesthetic result in a  penetrating facial injury.    tial intervention if the general condition of the patient and  expertise of surgeon permit and the benefits of such an  approach are manifold.    Several recent advances have significantly improved the  morbidity and survival rates in complex maxillofacial gun-  shot injuries. More importantly they serve as a support sys-  tem to the surgeons, enabling them to appreciate and attend  to the finer aspects of complex composite injuries. This in  turn paves the way to achieve far more superior reconstruc-  tive outcomes. Contemporary techniques employ virtual sur-  gical planning, patient-specific stereolithographic models, as  well as intraoperative navigation and imaging (Refer Chap.  41 of this book). These modern-day techniques help elevate  the surgical experience to one that is more precise, faster, and  minimally invasive.   Composite tissue alloplastic transplantation or face trans-  plantation is yet another recent innovation in this field. This  treatment is rendered for patients with massive loss of hard  and soft tissues of the face or in cases where the final out-  come is suboptimal even after multiple surgeries. However,  it is not in the mainstay treatment of gunshot wound of the  face because of the difficulties in finding an appropriate  donor, lack of expertise, requirement of long-term immuno-  suppressants, absence of long-term follow-up, and associ-  ated ethical issues.    In conclusion, the management strategies of patients with  facial gunshot wounds are almost as diverse as the case pre-  sentation itself. This chapter ascertains that the blueprint for  actions in the management of facial gunshot injuries has  undergone significant change over the last decade. A new  understanding of the inherent osteogenic potential of the  human body in the face of contemporary warfare coupled  with the availability of state-of-the-art equipments and facili-  ties favors a brisk early approach. Thus, present guidelines    essentially direct surgeons to do as much as possible for the  gunshot patient with regard to hard and soft tissue recon-  struction of the face and jaws within 48 hours. The treatment  in such cases is more comprehensive with intent to simulta-  neously debride and reconstruct.    . McLean JN, Moore CE, Yellin SA. Gunshot wounds to the face—    soft tissue gunshot and shrapnel injuries. J Oral Maxillofac Surg.  2003;61:1390-8.    injuries. 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Open Access This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.  org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropri-  ate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.   The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in  a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.   Most facial fractures occur in combinations involving vari-  ous subunits of craniomaxillofacial (CMF) skeleton [1]  (Fig. 60.1). Severity of these injuries is determined by mul-  tiple factors such as its aetiology, causative factor, force of  impact, pre-existing patient factors, etc: High velocity road  traffic accidents RTA / assaults are the most common cause  of panfacial fractures. With a large number of different pat-  terns these fractures project, it is challenging to have a proper  definition of “panfacial fractures”. It is well-known that frac-  tures involving multiple bones of the face is known as panfa-  cial fracture. It could be described as “fractures involving  upper third, middle third, and lower third of face with at least  one condyle, palate and fronto-naso-orbito-ethmoidal com-  plex (FNOE) fracture” (Fig. 60.2). When there is skull base  or co-existing neurosurgical involvement, it is termed as cra-  niofacial fracture. Managing these cases is extremely com-  plicated as each of them present with unique pattern of hard  and soft tissue injury. This demands a team approach as these  injuries are commonly seen in polytrauma with multisystem  involvement. Airway compromise, severe haemorrhage,  large open wounds, severe ocular/orbital injuries and coinci-  dental surgical procedure being performed are the only indi-  cations for immediate definitive surgical intervention.  Restoration of form and function at the earliest opportunity  should be the goal of maxillofacial surgeons.    Department of Oral and Maxillofacial Surgery, Bharati Vidyapeeth  Dental College and Hospital, Pune, Maharashtra, India    B. Kumar  Department of Maxillofacial Surgery, St. Marthas’s Hospital,  Bangalore, Karnataka, India    © The Association of Oral and Maxillofacial Surgeons of India 2021    Global status report on road safety (2015) indicates that  more than 1.25 million deaths, and 15—20 million injuries  occur in road traffic accidents (RTA) costing most countries  3% of their GDP [2]. Countries with low and middle income  having 54% of vehicles account for 90% of RTA-related  fatalities, mostly of subjects aged between 15 and 44 years.  RTA is the main cause of mortality in three quarters of males  in 15-29 years age group. The true economic and public  health impact is not estimated in most developing countries  due to lack of infrastructure and resources [3].   Panfacial fractures are caused by high-energy impact,  usually generated as a result of RTA or firearm injury directed  at CMF skeleton, and it also has a contrecoup component  causing associated cranio-cerebral or cervico-spinal injuries  with a low Glasgow coma scale. These injuries can also  cause associated injuries like rib fracture/pulmonary contu-  sion, pneumothorax or intra-abdominal injuries, limb and  pelvic injuries and require immediate treatment.    Restoration of form and function is the ultimate goal in treat-  ing panfacial injuries. Proximity to important structures like  the brain, eyes, auditory apparatus and spine necessitates a  holistic approach to their management involving neurosur-  geons, ophthalmic surgeons, ENT surgeons, maxillofacial  surgeons and anaesthetists.   It is challenging to follow an established pattern of repair  as each case is unique and requires skill and expertise of the  surgeon to restore the pre-traumatic anatomy of facial func-  tion with aesthetics. Despite all the aggressive treatment,  many patients with panfacial trauma may need further cor-  rection of residual deformities.    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1-15-1346-6_60    Fig.60.2 3D CT scan image showing panfacial fracture involving the  upper, middle and lower third of face    The management of panfacial fractures has changed during  past few decades, particularly after the 1990s, when indige-  nous plating systems were more freely available.    1. Prior to the 1980s, most panfacial fractures were treated  with closed reduction using Plaster of Paris (POP) head  caps and cranial frames. A variety of trans/interosseous  wiring techniques (see Chap. 50 for details on various  wiring techniques) and internal suspension methods like  cranio-mandibular/maxillary suspension were used  (Figs. 60.3a, b and 55.15).   2. The surgeons of the 1990s generation started using com-  bination of plating at key buttresses and internal suspen-  sion techniques [4]—the approach which may be  attributed to early learning curve of internal fixation  (Fig. 60.4).   of panfacial fractures [4] (Fig. 60.5a, b), leading to faster  recovery and satisfactory outcome of these injuries. (See  Chap. 51 for details on Principles of internal fixation)  A better understanding of anatomy, pathophysiology,  anaesthesia, sterilization and asepsis with advances in intu-  bation techniques (transmylohyoid/submental, broncho-  scopic) and instrumentation (fiberoptic and endoscopic)  and instrumentation has influenced the management of  these complex injuries significantly (Chap. 7 deals with  Anesthesia and intubation techniques in maxillofacial sur-  gery). Use of engineering technology like three-dimen-  sional planning, stereolithographic models, endoscopic  and navigation techniques has simplified the accurate treat-  ment of these fractures, avoiding injury to other vital struc-  tures and saving intra-operative time (Fig. 60.6a—d).    Panfacial fractures can be disfiguring and cause significant  functional problems like difficulty in mastication, deglutition,  speech, olfaction and abnormalities of vision. Early fixation  of displaced fractures causing the above problems is war-  ranted. Undisplaced/minimally displaced fractures can be left  for a few days, buying some time to manage other grievous  injuries: It is necessary to understand that sense of urgency  for treatment should exist in treating any panfacial fracture  (within 15 days, provided other parameters are permitting).    There are no absolute contraindications but relative contrain-  dications which cause delay of treatment, are presented below.    Fig.60.3 (a) POP head cap used in traditional days. (b) Interosseous wiring (yellow arrow) with internal suspension (blue arrow)    1. Definitive treatment of panfacial injuries may be delayed  up to 2 weeks in presence of severe, compromising, con-  comitant systemic or head injury.   2. It is advisable to operate only when patients are neuro-  logically and systemically stable. This period should be  used for further surgical assessment and planning.  Reduction of facial oedema further unmasks the underly-  ing fractures and facial deformity. This gives an opportu-  nity to review the imaging and prepare necessary splints  (see Sect. 55.7.1) (Fig. 60.7a, b). These are very essential  to establish width, height and anteroposterior projection  of the facial skeleton, particularly where large dento-    alveolar segments have been lost along with the presence  of bilateral condylar fracture.   3. When a combination of avulsive injury (Chap. 49 deals  with management of Soft tissue injuries in maxillofacial  region) and panfacial fractures is present, golden hour  reconstruction should be utilised, if circumstances and  conditions permit. This is the best time as patient is in  optimal physiologic and physical condition.    The clinical findings in panfacial trauma are a combination of  signs and symptoms as seen in various subunits of facial frac-  tures with increased severity (readers are advised to refer the  respective chapters on maxillofacial trauma for signs and  symptoms and management of fractures of mandible in  Chap. 52, Fractures of the Condyle in Chaps. 53 and 54, frac-  tures of maxilla in Chap. 55, fractures of the zygomatic com-  plex in Chap. 56, fractures of the orbit in Chap. 57, fractures  of the frontal naso orbit ethmoid region in Chap. 58 and Gun  shot injuries in Chap. 59).   Facial oedema makes examination and standard radiogra-  phy difficult. Bilateral raccoon’s eyes and elongated dish-  shaped face, with presence of orbital dystopia, traumatic  telecanthus and deranged occlusion, are commonly seen.  There may be elements of severe dento-alveolar trauma and  soft tissue injury which may vary from minor contused or  lacerated wounds (CLW) to avulsive injuries.    Fig. 60.5 (a, b) Plating of panfacial fractures as seen on (a) posterior-  anterior Caldwell view of mandible and (b) posterior-anterior Water  sinus view radiographs    Presence of cervical, cranial and other concomitant inju-  ries must be assumed till proved contrary. Similarly absence  of teeth, dentures in mouth must be assumed to have been  swallowed or aspirated until proven otherwise.    The pre operative planning consists of two parts: (a) imaging  and (b) diagnostic procedures.   Standard radiographs like posterior-anterior (PA) view,  Caldwell view of mandible, Water’s view, submento-vertex  view, cervical spine radiographs have been used as a baseline  in any emergency and are easily available in most settings.    Computed tomography (CT) images with 3D reconstruction  is now considered the gold standard in complex facial trauma  patients as it provides a 1:1 information of the fracture pat-  tern. 3D planning softwares help the surgeon in meticulously  planning cases preoperatively.   CT imaging is commonly done for assessment of brain  and spinal cord in a head injury patient to exclude intracra-  nial haemorrhage and other grievous injuries. Facial skeleton  should be included in the same scan in suspected facial bone  fractures.   Coronal and sagittal sections of the CT scan could be  obscured by the endotracheal tube in intubated patients.  Axial and three-dimensional images with computer-  generated models can be used for assessing most facial frac-  tures in these cases (Fig. 60.8a, b).   Occlusion of teeth is the key to reduction and fixation of  facial bone fractures. Mock surgery using dental models help  in repositioning the teeth-bearing segments including dento-  alveolar and palatal fractures and aid in fabricating acrylic  stents and splints (Fig. 60.7). They are essential in cases  where there is gross occlusal disturbance, splaying of basal  bone or multiple fractures of dento-alveolar segment.    Complex maxillofacial trauma are mostly high impact injuries  and are usually a part of life-threatening injuries involving other  organ systems like central nervous system, chest, abdomen, pel-  vis or limbs. It is important that these injuries be assessed and  managed prior to or simultaneously as facial injuries.   Current standards of care for trauma patients, whether  polytrauma or those involving the CMF skeleton, mandate  that one must follow the Advanced Trauma Life Support  (ATLS) protocol relating to airway, breathing, circulation,  disability and exposure in that sequence. Airway and circula-  tion should have the highest priority (Table 60.1). This is fol-  lowed by an assessment of the patient’s neurological, visual  and cervical spine status. The details of primary and emer-  gency management of polytrauma patients are dealt in  Chap. 48 of this book.   Patients with polytrauma/panfacial fractures can require  immediate or late treatment depending on the mechanism  and kind of injury. Occasionally, immediate treatment can be  the definitive procedure. An immediate intervention may be  done merely for initial stabilization of the patient; proce-  dures demanding a more detailed assessment and planning  will need to be postponed. Immediate initial treatment in  patients with maxillofacial injuries is indicated in following  situations.    Fig. 60.6 (a—d) Showing few of advances from various specialities of medicine and engineering contributing to advances in management of pan-  facial fractures. ((a) Bronchoscopic intubation, (b) transmylohyoid intubation, (c) fibreoptic instruments, surgical saw, (d) stereolithographic model)    Obstructed airway is an important sequel of panfacial frac-  tures and is managed either by temporarily reducing and sta-  bilizing the fractured facial bones and attached soft tissues or  performing a surgical tracheostomy. Patients with C-spine  injury can be challenging to intubate due to inability to flex  or extend the neck, as is establishment of a surgical airway  like tracheostomy.    Reduction and stabilization of fractured segments not only  helps to correct airway but also controls severe bleeding.  Haemorrhage not amenable to the above procedure may  necessitate packing, identification of causative bleeder and  its cauterisation or ligation. Occasional ECA control may    be required, if multiple ipsilateral bleeding areas or uniden-  tified areas of bleeding are seen. In centres where the facil-  ity is available, uncontrollable bleeding from facial region  (especially after comminuted midface fractures) is con-  trolled with selective embolisation by a interventional  radiologist.    These are commonly used to fix the fractures beneath them.  In such situations initial washout and primary approximation  should be done when possible for haemostasis and maintain-  ing continuity of vascular supply, especially in cartilaginous  areas like the ears and nose. This closure is basically a pri-  mary tacking of the wound margins. Layered closure is bet-  ter done under controlled conditions along with fixation of  the fractures under anesthesia [1].    Fig. 60.7 (a, b) Showing utility and essentiality of splints in management of panfacial fractures    Fig. 60.8 (a, b) Depicting importance of high-resolution CT scan in an avulsive injury to assess nature and extent of injury and achieve predict-    Occasionally, patients with polytrauma undergo immediate  surgery to treat other grievous injuries. This provides an  opportunity to perform initial debridement, assessment and  stabilisation and make dental impressions for fabrication of a  customised splint. Considering the planning and surgical  time required for comprehensive management of panfacial  fractures, it is usually not advisable or possible to perform  fixation during emergency management of other more severe  injuries (neurological/abdomen/long bones/chest).    It is always wise to initiate assessment of a head  injury or polytrauma patient using the ATLS (Advanced  Trauma Life Support) protocol. A detailed record of all  maxillofacial injuries should be made. Diagrams and  representations of fracture patterns and soft tissue inju-  ries make it easy for the understanding and execution of  treatment. It is important to document the whereabouts,  mechanism and time of injury accurately, to minimise  medico-legal problems at a later date. Photographs are a  good medium of educating the patients with their  attenders and recording the preoperative soft tissue  injuries.    Paul Manson’s quote “‘you never get a second chance” has to  be kept in mind, i.e. the time frame [5] regarded appropriate  for primary fracture treatment is limited to 2 weeks. After 2  weeks, the treatment is regarded as delayed and may neces-  sitate secondary post-traumatic reconstruction (see Chap. 60  on residual deformities of the maxillofacial region).    Preoperative treatment planning is essential for successful  outcomes. One must gather enough information and docu-  mentation to help in formulating an accurate treatment plan.   4. Assessment of important structures like parotid and  submandibular glands, nasolacrimal duct, trigemi-  nal nerve, facial nerve, muscles of eye and most  importantly vision    A proper evaluation by ophthalmologist, ENT surgeon  and Neuro Surgeon is mandatory before proceeding with  panfacial fracture fixation, and these allied specialities may  be part of the surgical team for comprehensive management  of the panfacial injuries.   Large bony defects with loss of soft tissue are best treated  immediately or secondarily with local, pedicled non-    vascularised or vascularised-free flaps provided the wound is  clean and non-infected. Tissue shrinkage should be avoided  as much as possible in these special situations by using tech-  niques of maxillomandibular fixation (MMF) and internal or  external fixation devices or splints. Immediate reconstruc-  tion can be planned in clean wounds. Need for transmylohy-  oid/submental endotracheal intubation as an alternative to  tracheostomy should be explored in discussion with the  anaesthesia team [6], especially in panfacial trauma involv-  ing nasal bones and skull base fractures needing fixation of  maxilla and mandible.   The essential in treating panfacial fractures is obtaining  adequate fixation at key buttresses (Fig. 60.9a, b, Fig 55.2).  Its description was first given by Cryer in 1916 [7]. This  helps in creating the outer framework for fixation of other  fractures.    These are the regions of thick bones which neutralise the  forces applied onto them.   Outcome of maxillofacial reconstruction in terms of res-  toration of facial height, width and projection in addition to  restoring the occlusion depends on proper reduction and  fixation of these buttresses [8, 9] (Table 60.2).   3. Protection of skull base and structures above like  brain and eye with their adjoining structures from  masticatory forces    ¢ Central facial width: fronto-naso-orbital-ethmoid (FNOE)  complex, palate and the mandibular arch   ¢ Lateral facial width: Frontal bar, zygomatic arches, malar  eminences and mandibular angles   ¢ Projection: frontal bone, frontonasomaxillary buttresses,  zygomatic arches and mandible from angle to symphysis   ¢ Facial height: frontal bone, midface buttresses, mandibu-  lar angles and condyles    Fig. 60.9 (a, b) Schematic  markings of facial buttresses  (Correlate with Table 60.2)  (Also see Fig. 55.2)    Nasomaxillary (red) Frontal (orange)  Zygomaticomaxillary (purple) Zygomatic (orange)  Pterygomaxillary Maxillary (blue)    Approaches to individual facial bones are discussed in the  respective sections of the book. They are enumerated here  for quick reference and revision.   Facial lacerations overlying fractures should be used for  access when possible (Fig. 60.10a—d). In situations without  any such lacerations, appropriate incisions for respective  fractures should be used as described in other sections of this  book.   Subciliary or transconjunctival incisions are commonly used  to provide access to infraorbital rim and orbital floor; lateral  brow or upper blepharoplasty incisions provide access to fron-  tozygomatic suture and lateral wall of orbit; intraoral vestibular  incision provides access to maxilla and zygomatic buttress; and  coronal incision provides access to frontal, fronto-naso-ethmoid  complex, zygomatic arches and roof of orbit.   Mandible symphysis, parasymphysis, can be approached  through intraoral vestibular or crevicular incisions.  Mandibular angle is approached intraorally through an  extended 3rd molar incision alone or in combination with    a transbuccal approach using a trochar and cannula. The  condylar head will need to be approached through preau-  ricular or bicoronal incision, whereas the mandibular sub-  condyle and ramus can be approached through  retromandibular or peri-angular incision. Endoscopic  approach to the mandibular condyle is been popularised in  a few units (see Chap. 54 for details on endoscopic  approach to condylar fractures).   Sequencing of fixation in panfacial fractures is a chal-  lenging task. The sequencing will alter slightly depending on  clinical and radiological evaluation.    1. Bottom to top [10, 11]: This involves restoring the maxil-  lomandibular unit using occlusion as guide and fixing  maxilla and mandible using semi-rigid or rigid fixation  techniques. Thereon reduction and fixation proceeds in  caudal direction starting from calvarium. The other frac-  tures are then restored in a build-out fashion with maxilla  and mandible being a stable base   2. Top to bottom: This involves starting with the reduction  and fixation at the level of the calvarium. Then the opera-  tor proceeds in a caudal direction with reduction and fixa-  tion. In this top to bottom sequencing technique,  establishing proper occlusion with MMF is no less    1. When using this approach one is committed to using the  mandible as guide for establishing the height, width and  projection of face. Hence after occlusion is established,  the mandible is rigidly fixed from one condyle to the  other. This makes it necessary to plate minimum one con-    dyle in case bilateral condylar fracture. It is necessary to  ensure proper seating of mandibular condyle into the gle-  noid fossa.    of palatal fracture and its nature (comminuted or not). In  any case it is very important to establish width of midface  correctly so as to achieve optimal functional and aesthetic  results.    . Use of splints made on dental models after model surgery    serves an ideal and desirable method to establish correct  width of middle and lower face particularly when there is  comminution of maxilla and mandible. Use of conven-  tional acrylic splints is the easiest and least time consum-  ing. 3D splint has led to more accurate and predictable  results but adds on to the time and cost.    4. The next step is to begin the reduction and fixation of the  remainder of the midface starting from the calvarium and  working in a caudal direction similar to “top to down”  sequencing.    1. The reconstruction sequence to re-establish midfacial pil-  lars (buttresses) and dimensions starts with the most reli-  able and stable point on calvarium and on the side with  the least comminution.   2. The calvarial, frontal sinus and orbital roof fractures are  addressed first using stable point/region on calvarium as  reference point for reconstruction of midface.   3. The zygoma is positioned into its proper three-  dimensional position, almost as a flat structure and con-  firming that lateral wall of orbit is in alignment with the  greater wing of sphenoid. This helps proper establish-  ment of width and anterior-posterior projection of face.  Approximation of the sphenozygomatic suture in the lat-  eral wall of the orbit should be a guide to reduction in  cases of comminuted zygomatic fractures [12]    Fixing the zygomatic arch increases the accuracy of mul-  tidimensional reconstruction (frontozygomatic suture,  infraorbital rim, zygomaticomaxillary buttress, zygomatic  arch) of fractured and comminuted zygoma [13, 14].    essary, it can be addressed towards the end of the  procedure.    the Le-Fort I and II level. Maxillomandibular fixation  may be done at this stage. If everything has been perfectly  aligned, these fractures should also align adequately.  Splints play a significant role in determining the facial  width at Le-fort I level. Malalignment at this level signi-  fies need for reassessment and realignment of previously  fixed fractures.   The midface, because of weak bone structure and com-  minuted fracture pattern, must be considered a dependent  and less stable structure.   From an aesthetic standpoint, a minimal malalignment at  the Le-Fort I level is not as noticeable as a malalignment  of the orbits.   Fractures of the inferior orbital rim and orbital floor can  be now addressed as the true volume of the orbital defect  can be seen once other fractures are aligned.   The mandibular fractures are then fixed. Condyle frac-  tures may be addressed with separate incisions or man-  aged conservatively depending on the displacement and  influence on the vertical height of the mandible, as dis-  cussed previously.   Tulio etal advocated fixation of condylar fractures as the  first step in fixation of pan facial fractures. In their study  there was no evidence of dental or skeletal alterations and  measurement of the mandibular ramus and radiographic  examination show that posterior facial height as well as  projection and width of the inferior lower third of the  face, was restored. The correct timing of surgical inter-  vention and the use of rigid fixation allows the restoration  of the morphological and functional nature of the face  after pan facial fractures [15].   The occlusion should be rechecked, and rigid or elastic  maxillomandibular fixation may be considered as neces-  sary for 4-6 weeks. The occlusal splints may be fixed  using wires for the period of MMF as a guide to main-  taining the occlusion.   The sequencing for pan-facial fractures depends more on  the clinical situation, than on predefined algorithms as the  patterns of clinical presentation may be diverse. However,  the general consensus in current literature emphasizes  that the the dental units are given priority for providing  guidance. The dental arches are first stabilised to form a    Table 60.3 Bottom-up inside-out and top-down outside-in, compari-  son of sequencing    Bottom-up  Maxillomandibular fixation  (MMP), splints for palate and  mandibular lingual in case of  gross comminution    Fix zygomaticomaxillary complex  (including arch) fractures, with  proper alignment of infraorbital  rims   Fix naso-orbito-ethmoid complex,  and nasal fractures  Maxillomandibular fixation  (MMP), splints for palate and  mandibular lingual in case of  gross comminution    Fix condylar fractures, at least  one when fracture is bilateral  Fix maxilla at LeFort I level   Fix zygomaticomaxillary  complex (including arch)  fractures, with proper alignment  of infraorbital rims    cohesive unit, followed by the mandible in its horizontal  and vertical dimensions (10, 19) (also see Manson 2012  in additional reading). The mid face is then managed  using a top-down or a bottom-up method depending on  the presence or absence of bony defects in the calvarium.    1. Soft tissue repair and closure of wounds/incisions of  intraoral and pharyngeal areas should be done prior to  maxillomandibular fixation. In some cases it might be  essential to temporarily release MMF to close lacerations  and redo MMF later.   4. Extraoral incisions and lacerations communicating with  the oral cavity should be closed from deep (mucosal) to  superficial (skin) in multiple layers.    The sequence of the above approaches are compared in  Table 60.3.   It is author’s preference to use initial wire osteosynthesis  stainless steel (SS) for better alignment and anatomical  reduction at multiple sites before plating. This technique also  does away with the requirement of holding fragments  together, and with less of instrumentation in the surgical    Fig.60.12 Three concentric circles used as a guide to the reduction of  panfacial fractures (Adapted from: H.C Killey. Fractures of Middle-  third of facial Skeleton, Issue 3 of Dental Practitioners Handbook,  No.3)    field, there is an obvious ease of plating more precisely. Wire  osteosynthesis should be removed following fixation of the  fractures to avoid or prevent reaction between dissimilar  metals, namely, SS (stainless steel) and Ti (titanium).   There are other sequencing methodologies and philoso-  phies as suggested by other authors.   Manson et al. put forward a highly conceptualised treat-  ment protocol where face is divided into groups, units and  sections, and each section is assembled in three dimensions.  Soft tissue is considered the “fourth dimension” of facial  reconstruction. They advised bone reconstruction to be com-  pleted as early as possible to minimise soft tissue shrinkage,  stiffness and scarring of soft tissues in non-anatomic position  [1, 16].   Killey and Kay demonstrated the fixation of panfacial  fractures first in the outer ring followed by the middle ring  and lastly the nasal complex in the inner ring (Fig. 60.12).   Inside-out sequence was also found to show good results  by Kim et al. [17].    The occlusion first approach, with initial reduction of  larger segments, enables effective reconstruction of multiple  segments. Smaller segments can then be oriented to fixation  of these fractures [18].   Role of bone grafts in very comminuted fractures or miss-  ing bone demands immediate bone grafting to produce a  stable outcome. Commonly used areas of bone and cartilage  grafts are rib, calvarium, iliac crest and conchal cartilage  [19]. Recipient site requirements determine the ideal donor  site for replacing bone. Revascularisation potential and  mechanical needs of the donor site are two factors known to  influence this [20].    They are rare and different as the cranium to face ratio is  8:1, and also differential growth in eyes, brain and face  makes a difference in pattern and incidence of fractures.  Children should not be treated as small adults as its not only  important to restore them to normal form and function, but  the growth potential also should be taken into consideration.  One must remember that both injury and treatment can lead  to growth disturbances, and hence many times conservative  management is preferred. Splints are the mainstay in treat-  ment of paediatric fractures (Figs. 52.50 and 52.51).  Panfacial fractures are preferably treated with resorbable  plates to prevent growth disturbances and damage to tooth  buds. This also avoids second surgery for plate removal.  Furher, it must be kept in mind that minor occlusal discrep-  ancies are self-corrective during transitional dentition phase  or can be treated easily with orthodontics at later date. Major  emphasis should be on preventing deformities in central  midface. Paediatric patients have to be followed up till  growth has completed. In developing countries wire/resorb-  able suture osteosynthesis can be utilised for economic rea-  sons and availability [21].    Complications associated with panfacial injuries include  those associated with individual fractures of frontal sinus,  nasal and fronto-naso-ethmoid, zygomatic, maxillary and  mandibular fractures.    ¢ Motor and sensory deficits of motor and sensory nerves  like anaesthesia, paresthesia and weakness    Increase in facial width secondary to reduction of anterior-  posterior facial projection    of surgery. Use of patient photographs prior to injury  may act as a guide for the surgeon to establish treatment  goals. This may be challenging to assess with the oedema  and disfigurement following trauma. Making a record of  intra-operative and post-operative photographs is a good  practice for comparison and documentation.    ally displaced mandibular condyles, it is important to fix  at least one condyle anatomically by open method in  order to obtain adequate mandibular positioning and  posterior facial height.   In either approaches to panfacial fractures seating of  condyle into glenoid fossa is absolutely mandatory.   Vertical and horizontal buttresses should be established  and fixed (to attain correct facial width and height)  before orbital walls and rim correction.    . Special attention should be paid to soft tissue repair and    calvarial bone graft for bony augmentation and recon-  struction like in blow-out orbital fractures.   Establish zygomatic arch as linear structure to get per-  fect facial projection and width.   Inadequate and delayed FNOE complex fractures treat-  ment is usually a disaster and at most times is only par-  tially correctable by secondary surgeries.    Preoperative arch impressions and splints fabrication  have a major role to play in preventing oro-nasal com-  munication and establishing facial width.   MMF is mandatory for proper occlusion  operatively. Elastics may be needed during follow-up.  Most common residual deformity associated with panfa-  cial fractures is lack of projection, increased facial width,  malocclusion, enophthalmos and lacrimal dysfunction.  Complete removal of all mucosa and blockage/sealing  of fronto-nasal duct should be done before cranialisation  or obliteration of frontal sinus.   Documentation of details of injury is essential of  medico-legal reasons, more so of the mechanism and  time of injury; these details if necessary can be noted  from other observers. Photographs can serve as legal  documentation. These should be taken following a valid  patient consent.   Close soft tissues from deep to superficial and from  intraoral to extraoral. Complete intraoral closure prior to   Forced duction test is essential before and during sur-  gery in fractures involving orbital walls (Fig. 56.21).  Caution: removal of throat pack is a joint responsibility  of the anaesthetist and surgeon.    Case 1:  (Figs. 60.13a—d, 60.14a-f, and 60.15a—c) Shows  Management of a Case of Pan Facial Fracture    Figure 60.13 shows the pre operative CT scans, Fig. 60.14  show the various surgical approaches used for internal fixa-    tion and Fig. 60.14 shows the post operative radiographs  showing the fixation.    (a—d) Panfacial trauma preoperative CT scan. (a) Right condylar fracture. (b) Naso-ethmoid complex fracture, left zygomatic buttress  and infraorbital rim fracture. (c) Mandibular symphysis fracture. (d) Left condylar fracture    Fig.60.14 (a—f) Panfacial trauma intra-operative images of case shown in Fig. 60.14. (a) Left retromandibular approach (b) Right retromandibu-  lar approach. (c) Right condyle plating. (d) Symphysis exposure. (e) Right frontozygomatic fracture. (f) Naso-ethmoid fracture exposure    Fig.60.15 (a—c) Panfacial  trauma post-operative  radiographs of case shown in  Fig. 6 . (a) OPG. (b) PA  cephalogram. (c) Lateral  cephalogram   (a) Frontal view showing  asymmetrical face, alar bases,  lip and deepened supra tarsal  fold (yellow arrow).   (b) Lateral view showing  upturned lip, increased  vertical dimension, scar on  left body of mandible.   (c) Malocclusion with anterior  open bite. (d) Pre-operative  P.A. Waters view showing  inadequate fixation of  midfacial fractures and  foreign body within right  orbit (Red arrow)   This case was treated in 1997 by the first author, when CT  scan was a novelty rather than necessity. Plating system used  was stainless steel.   A 43 years male with no comorbidities was referred by  dental surgeon for correction of malocclusion and asymmet-  rical face. Patient had a history of RTA with panfacial frac-  tures, and head injury, cerebral oedema 3 months prior. He  was treated conservatively for head injury and had no resid-  ual neurological deficit. He was treated by other specialist  for panfacial fractures by ORIF and then referred to dentist  for prosthetic correction of occlusion. Patient insisted upon  simultaneous correction of occlusion and asymmetric face.   Inability to masticate, changed pattern of upper and lower  teeth meeting , crooked nose with asymmetric nasal bases,  sunken left eyeball, diplopia on superior gaze, and changed  facial appearance compared to preinjury status.    Significant change in facial appearance as com-  pared to pre-trauma, pre-treatment appearance    . Elongated face  . Upturned upper lip and acute nasolabial angle  . Deviated and depressed nose, with dissimilar alar    . Increased width of face more so on left side  . Malocclusion, with anterior open bite, increased    vertical dimension of face due to posterior and  inferior displacement of maxilla with gagging.   Left mandibular body fracture fixed adequately  but patient had left marginal mandibular nerve  paresis/ injury.   Total mobility of middle third of facial skeleton  suggestive of non-union/malunion.    Fig. 60.17 (a—d) Intra-operative representative photos. (a) Fixation at FZ suture. (b) Fixation at inferior orbital rim. (¢) Entrapment of inferior  rectus, left orbital floor (yellow arrow). (d) Fixation of LeFort I fracture. (e) Fixation of bone graft to augment nasal bridge    Patient was counselled and asked to undergo X-rays  to have 3 dimensional orientation. 1. PA Caldwell.  PA Water sinus (full face),   Base of skull for zygomatic arches and mandible.  Upper and lower occlusal topographic. CT scan of  face with 3D reconstruction was not done for finan-  cial reasons. Remember CT scans were relatively  expensive then.   Inadequate fixation seen at bilateral Fronto Zygomatic  (FZ) suture, LeFort LJIII level, and FNOE complex.  A Foreign body (broken drill) was seen in Right orbit  near FZ suture ( red arrow). Mandible was fixed ade-  quately both radiologically and clinically.    Transmylohyoid intubation.  Mandible fracture being adequately fixed during  previous surgery was not addressed    at FZ suture, and left infraorbital region, subcili-  ary approach to right infraorbital region.    Fig. 60.18 (a—d) Ten years Post-operative photographs. (a) Frontal  view showing restored symmetry. (b) Lateral view showing correct lip  positioning, corrected vertical dimension, scar on left body of mandible.    10. Avoid MMF. Post-op X-ray (Fig. 60.18d) shows  plating with wires, they were not removed as hard-  ware used then was stainless steel so there was no  issue of Eddy’s current due to dissimilar metals.    The increasing number of RTA and related CMF injuries sug-  gests the need for immediate attention from the concerned  authorities, to enforce strict laws like mandatory use of seat  belts and total head and face guard (that suit climatic condi-  tions) rather than the conventional helmets. Restricting the  use of mobile phones and head phones while driving may    (ce) Corrected occlusion. (d) Post-operative P.A. Waters view (Full face)  showing adequate fixation of midfacial fractures at all the struts    lead to decrease in the incidence of RTA. If RTA is considered  an epidemic of modern times, then prevention is its vaccine.  Increasing public awareness towards voluntary use of safety  measures for their own safety rather than merely obeying the  rules can reduce most of the cranio-maxillofacial injuries.   Panfacial trauma can appear complex and challenging to  treat but is actually the conglomeration of treating individ-  ual fractures that are a common place in maxillofacial inju-  ries (it would be wise to “simplify” the fracture in the  minds’ eye view and formulating a treatment plan).  Adhering to a treatment protocol and treating each fracture  as a unit, with adequate fixation, enable the surgeon to  obtain good results. Development of a sequential and  methodical treatment plan prior to surgery and adherence  to the basic principles of maxillofacial trauma is vital in  treatment of these patients.    . Kelly KJ, Manson PN, Vander Kolk CA, Markowitz BL, Dunham    CM, Rumley TO, Crawley WA. Sequencing LeFort fracture  treatment (Organization of treatment for a panfacial fracture). J  Craniofac Surg. 1990;1(4):168-78.    . Gadre KS, et al. Incidence and pattern of cranio-maxillofacial inju-    ries: a 22 year retrospective analysis of cases operated at major  trauma hospitals/centres in Pune, India. J Maxillofac Oral Surg.  2013;12(4):372-8.    . Gruss JS, Phillips JH. Complex facial trauma: the evolving role of    rigid fixation and immediate bone graft reconstruction. Clin Plast  Surg. 1989;16:93-104.    . Manson PN, Crawley WA, Yaremchuk M, et al. Midface fractures:    advantages of immediate extended open reduction and bone graft-  ing. Plast Reconstr Surg. 1985;76:1-12.   PP. Transmylohyoid/submental intuba-  tion: review, analysis, and refinements. J Craniofac Surg.  2010;21:516-9.    . Cryer MH. The maxillae. In: The internal anatomy of the face.    eton: an approach to the management of Le Fort fractures. Plast  Reconstr Surg. 1980;66:54-62.    . Manson PN, Clark N, Robertson B, Slezak S, Wheatly M,    Vander Kolk C, Iliff N. Subunit principles in midface fractures:  the importance of sagittal buttresses,soft-tissue reductions, and  sequencing treatment of segmental fractures. Plast Reconstr Surg.  1999; 103(4):1287—306.   Curtis W, Horswell BB. Panfacial fractures: an approach to man-  agement. Oral Maxillofac Surg Clin North Am. 2013;25(4):649-60.  Yang R, Zhang C, Liu Y, Li Z, Li Z. Why should we start from  mandibular fractures in the treatment of panfacial fractures? J Oral  Maxillofac Surg. 2012;70(6): 1386-92.   Rohner D, Tay A, Meny CS, et al. The sphenozygomatic suture  as a key site for osteosynthesis of the orbitozygomatic com-  plex in panfacial fractures: a biomechanical study in human   Stanley RB Jr. The zygomatic arch as a guide to reconstruction of  comminuted malar fractures. Arch Otolaryngol Head Neck Surg.  1989;1150:1459-62.   Gruss JS, Van Wyck L, Phillips JH, Antonyshyn O. The impor-  tance of the zygomatic arch in complex midfacial fracture repair  and correction of posttraumatic orbitozygomatic deformities. Plast  Reconstr Surg. 1990;85(6):878—90.   Tullio A, Sesenna E. Role of surgical reduction of condylar frac-  tures in the management of panfacial fractures. Br J Oral Maxillofac  Surg. 2000;38(5):472-6.   Markowitz BL, Manson PN. Panfacial fractures: organization of  treatment. Clin Plast Surg. 1989;16:105—14.   Kim J, Choi JH, Chung YK, Kim SW. Panfacial bone fracture and  medial to lateral approach. Arch Craniofac Surg. 2016;17(4):181-5.  Choi JW, Kim MJ. Treatment of panfacial fractures and three-  dimensional outcome analysis: the occlusion first approach. J  Craniofac Surg. 2019;30(4): 1255-8.   Gruss JS, Mackinnon SE, Kassel EE, et al. The role of primary bone  grafting in complex craniomaxillofacial trauma. Plast Reconstr  Surg. 1985;75:17-24.   Phillips JH, Forrest CR, Gruss JS. Current concepts in the use of  bone grafts in facial fractures. Basic science considerations. Clin  Plast Surg. 1992;19:41-58.   Iatrou I, et al. Surgical protocols and outcome for the treatment  of maxillofacial fractures in children: 9 years’ experience. J  Craniomaxillofac Surg. 2010;38:511-6.    J, editors. Principles of Internal Fixation of the Craniomaxillofacial  Skeleton, Trauma and Orthognathic Surgery. Thieme; 2012. p  292-305.    Open Access This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.  org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropri-  ate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.    The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in    a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.    61.1 Introduction  A maxillofacial surgeon plays a vital role in not only restor-  ing the structural form of the maxillofacial unit but also aims  to restore the pre-traumatic functional status of the patient.  Diagnosis, clinical evaluation with enhanced treatment plan-  ning and restoration of aesthetics and function is the key for  any maxillofacial surgery. However, it is not always possible  to achieve the most appropriate results in all cases. It is not  uncommon to see failure or mediocre outcomes following  maxillofacial trauma surgery. The outcome of the primary  treatment may depend on factors such as the extent of the  injury/defect, delay in diagnosis/management, improper  treatment plan, lack of utilizing modern diagnostic/treatment  planning utilities, poor execution of treatment plan and inex-  perience of the surgeon. These may lead to not expecting the  eventful deformities and not coordinating with other special-  ists to yield the most standard and deserving treatment for  the patient with restoration of both form and function [1-3].  Residual deformities are seen following primary treat-  ment of trauma due to one more reason mentioned earlier.  Correction of such residual deformities may be challenging  to the surgeon but very often a life-changing experience for  patients. It is the experience of the surgeon that helps to  recognise the challenges ahead in restoring the form and  function. Residual deformities are often evaluated by the  extent of deformities following primary management.  Apart from reasons that may pertain to the experience of  the operating surgeon, pathobiology of the healing zone  may also contribute to the residual deformities. A variety of  such reasons contributes to both soft tissue and hard tissue  defects in the maxillofacial unit. This chapter aims to dis-  cuss in detail the clinical evaluation, diagnosis, protocols,    S. Jimson   Department of Oral and Maxillofacial Surgery, Tagore Dental  College and hospital, Chennai, India    © The Association of Oral and Maxillofacial Surgeons of India 2021    management and post-operative care of hard tissue  deformities in oral and maxillofacial surgery with emphasis  on current trends and future propositions.    Wound management begins right after the soft tissue injury  in the primary or acute stage.   e Wound care management by the use of agents that  promote healing    Soft tissue injuries/scar revision/soft tissue and hard tissue  reconstruction related to management of residual deformities  have been dealt in detail in respective chapters of this book  (refer Chaps. 36, 49, 86 and 88). Wound care and management  begin with preventive measures.    This section briefly discusses management of volume defects  using tissue expanders. Volume issues are to be considered  with all excision techniques. Loss of tissue volume due to  trauma or contraction of the scar may lead to depression and    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1 -15-1346-6_61    distortions that are more obvious than the original scar. Such  loss of tissue may require volume replacement that can be  achieved by other techniques. Surgical flaps may be com-  monly used to fill the tissues. Likewise, biological fillers can  also be taken into consideration in managing depressed or  irregular areas. Tissue debulking can be done whenever there  is an excess of tissue volume.   Two methods of tissue transfer can be opted whenever  there is loss of tissue: a free skin graft and a skin flap. A free  skin graft of limited thickness involves the complete removal  from the donor site and then placement on the recipient site  for survival. This type of graft will not survive in avascular  recipient sites. A skin flap with underlying subcutaneous tis-  sue will carry its blood supply necessary for the survival of  the flap. These skin flaps are further divided into local flaps  or distant flaps (from distant sites). Single-stage transfer of  flaps may be done with microvascular surgical techniques  (Chart 61.1 shows types of soft tissue deformities with rela-  tion to the volume defects).   ¢ Local flaps should always be considered in case of minor  loss of tissue. Facial tissue is naturally the first choice due to  the colour and texture for replacement of tissue defects that  are not too extensive. In such cases of local flaps, skin bor-  dering the deformity should be raised and rotated into the  defect, approximating the scar in a favourable position.   e Small scar defects may not yield a good result with split  skin grafts, but full-thickness grafts can potentially give  good aesthetic results in the repair of small defects.   ¢ Lower eyelid scarring due to ectropion may be corrected  using full-thickness graft (Wolfe’s graft) that results in  predictable function and aesthetics.   e Traumatic or gunshot injuries may result in a substantial  loss of tissues. Majorly these injuries are associated with  loss of soft tissue and skeletal structure.   e The replacement of tissue should involve necessary cov-  ering, lining and support to the bone or cartilage.   ¢ Flaps used in all anatomical structures like the antrum,  orbit, mouth and nose should have necessary lining epi-  thelium; otherwise it will result in contraction of the tis-  sues and exposure of underlying tissues.   ¢ Complications like nasal airway stenosis, oral stenosis,  microsomia and obliterated buccal/labial sulcus may  occur.   e A split skin graft may be used in case of nasal or buccal  defect.   ¢ Double flap with both inner and outer aspects composed of  full-thickness skin or subcutaneous tissue may help to  increase the flexibility in case of a cheek flap. In such cases,  the extent of fibrosis is decreased and thereby helps in  increasing flexibility due to the underlying vascularity.   e Nasal lining may be provided by approximating the adja-  cent in-turned flaps of skin around the surrounding  defects. A split skin graft should be preferred whenever  such approximation is not possible. Hard tissue nasal  deformities are discussed elsewhere.   ¢ Lip defects may result in loss of larger tissue. Contraction  due to lip re-suture may result in the loss of one-third of  the available tissue. Local tissue flaps as full-thickness  flaps should be considered ahead of tube pedicle flaps.  Whenever permissible, it is better to take a full-thickness  flap of the cheek or buccal mucosa, rotate it and form a lip  and fill the subsequent secondary defect with tube  pedicle.    e Scar adhesions of the sulcus or obliteration of sulci due to  deficient tissues may predispose the difficulty in the con-  struction of a functional and stable prosthesis. The fibrous  scar tissue may be excised, or the sulci may be created  with dissection followed by insertion of a free split skin  graft.   ¢ Palate: Substantial loss of tissue may involve the hard  palate, soft palate or both areas. Generally, loss of tissue  in the hard palate may be closed with an obturator. Scar  tissue associated with the hard tissue defect may be man-  aged by dividing the fibrous scar bands and restoring the  residual tissues. Rotational flaps may also be used to close  the defects. Tissues from additional sources may be used  in the closure by using full-thickness flaps. Two-staged  full-thickness flaps from the lateral third of the tongue are  used, the base of which is divided after 3 weeks. In case  of larger defects, myofascial temporalis flaps may be used  with downward rotation, and following osteotomy of the  zygomatic arch, it may be passed through a mucosal tun-  nel to reach the oral cavity. Both the flaps provide better  results, but the advantage of the latter is being a single-  staged technique [3].    Tissue expanders are the advised treatment technique when  the loss of tissue or the scar surface areas are larger. It is  indicated in revision or excision of scar where local or  regional flaps may not be feasible to be used in the immedi-  ate reconstruction. Although commonly employed for tissue  expansion in forehead and scalp, it may be beneficial for any  areas with larger defects. Tissue expansion becomes an ideal  choice in the scalp due to its inelasticity. It allows replace-  ment of defects with adjacent surrounding tissue which is  similar in colour, texture, adnexal structures and innervation  (Fig. 61.1)    61.1.3.1 Properties of Tissue Expanders  4, 2 7-9]  Silastic balloons with self-sealing valves which are used as    e These tissue expanders are available in different shapes  and sizes and can also be custom-made to fit an irregu-  larly bordered defect.   e It is important to choose an expander of sufficient size to  provide the necessary expansive force required for the  need in tissue gain for reconstruction.   e The expander has to be 2.5 times that of the scar to be cor-  rected while using a rectangular or crescent-shaped  expander. On the other hand, the diameter of the base of  the circular expander should be 2.5 times that of the scar  to be replaced.   ¢ The expanders must be implanted in a position where ide-  ally a simple advancement, rotation or transposition flaps  may be developed later.   ¢ The goal is to have the adjacent healthy tissue expanded  and not the scar itself. Hence, the proper placement of the  tissue expander is vital.   ¢ Scarred, atrophic areas or sites that have undergone prior  radiation therapy are contraindicated.   During the period of tissue expansion, a capsule is formed,  and the epidermis is thickened and expanded. Increased  mitotic activity is seen evidently using the microscope during  the expansion. The dermal thickness, which decreases during  the expansion phase, returns to normalcy in 2-3 years.  Expanders may also result in decreased adjacent muscle  thickness, but without any loss of function. The adipose cells  may decrease in number, and subcutaneous thinning may also  be seen. Viability of expander is maintained with increased  angiogenesis. Bone remodelling may also take place beneath    the expander. The morphology and number of hair follicles  are usually not affected, and hence this is a key in scalp  expansion. Treatment duration can be reduced in areas where  more than one expander can be placed. The gradual stretching  of the tissue over the expanding subcutaneous tissue is called  biological creep. Placement of the balloons and allowing a  series of inflations and deflations to result in the stretching of  the skin are the principles behind tissue expanders. This  inherent nature of the skin to expand beyond its natural exten-  sibility is referred to mechanical creep [4, 10].   Expanders are implanted by making incisions at the junction of  the scar and the healthy tissue. A pocket is made in an avascular  fascial plane. Wound closure is done with layers over the  expander. 10% volume of expander may be added at the time of  surgery to minimise chances of hematoma formation around the  expander. Necrosis of the overlying tissues may occur if any  wrinkles are present over the surface of the expanders. If the site  allows area for placement for more than one expander, it may  reduce the overall treatment duration. Two weeks after place-  ment, the expanders are inflated once or twice in a week. Patient  discomfort or blanching over the surface of expander should be  observed. Overexpansion of tissue is necessary as there will be  a degree of contraction after removal of the expander. Likewise,  bony contour changes usually regress without any intervention.  The capsule of the expander is released along its margins but is  left intact (Fig. 61.2). Generally, a waiting period of 2 weeks  should be observed before proceeding to the next stage of the  surgery/procedure. This allows the skin tension to reduce before  the next stage of the surgery [4, 5].   Local usage of tissue by expansion helps in the preservation  of the sensation, vascularity and the adnexal structures. This  aids well in both aesthetic and functional aspects.   e A temporarily visible deformity when the expander reaches  its full inflation may not be socially acceptable by the patient.   ¢ Necrosis and tissue breakdown leading to exposure of the  expander   ¢ Decreased patient compliance and psychological stress  for the patient as the expander increases in size creating a  transient compromise in aesthetics    Fig. 61.2 Conventional method of tissue expander in management of  scar tissue. (a) Expander placed near scar tissue and tissue expansion  seen. (b) Adjacent scar tissue removed before closure. (c) Over-  expanded tissue closed with adjacent scar tissue removed and the cap-  sule is left intact with release along its margin    This chapter further discusses the use of grafts in residual  deformities, management of hard tissue residual deformities  and recent advances.    Soft tissue and hard tissue defects are best managed by the  use of grafts. Secondary or residual use of grafts and flaps  is essential in restoring the hard tissue and soft tissue  defects. The scope of this chapter briefly describes grafts  used in residual deformities. This section also outlines the    biology behind bone grafting and types of bone grafts  (Chart 61.2).    Biology of bone grafting includes the following rationale  [12-17] (Table 61.1):    Osteoconduction Mechanism in which the graft substance serves as  a scaffold for new bone growth aided by native  bone. Osteoblasts from the source utilize the bone  graft as a structural scaffold on which new bone  generation takes place. A bone graft should be  ideally osteoconductive. Ex: Calcium sulphate,  calcium phosphate cements, ceramics, collagen,  synthetic polymers   Mechanism involves stimulation of  osteoprogenitor cells — differentiation into  osteoblasts > formation of new bone. Ex: Bone  morphogenic proteins. It is ideal to have grafts that  are osteoconductive and osteoinductive in nature  Ex: DBM (Demineralised Bone Graft), BMPs,  growth factors, genetic therapy   Enhancing osteoconduction without  osteoinductive properties. It promotes action and  can’t grow bone independently. Ex: Enamel  matrix derivative enhances the osteoinductive  property of demineralised freeze-dried bone  allograft   Formation of new bone with the help of  osteoblasts originating from the bone graft  material. Ex: Bone marrow aspirate (BMA)    e It should be easily and readily available and should  not require additional surgical intervention in a sec-  ond donor site.    Grafts play a major role in primary or secondary/residual  management, eventually playing plays a vital role in  reconstruction. Bone grafts in residual deformities are  ideal to fill volume defects and also aid in reconstruction.  Various types and sources of grafts have already been  listed (Chart 61.3).    Type Highlights Deformities  Autografts ¢ Bone grafting from the same individual  : ed ele tes from nonessential sites 61.2.3.1 Nasal Deformities [19]  ° t t 5 : :  See Ge ee. prdloceoeenic ¢ Bone grafts for nasal deformities can be readily obtained  * Requires an additional surgical site and risk of from cranial bone or iliac bone crest. Costochondral and  infection, pain and complications in the donor tibial bone grafts have also been used earlier. Cartilage  ue ; : may be harvested from nasal septum. It may also be har-  ¢ Gold standard and available in many forms é  : —— vested from conchal bowl of the ear in case of septal bone  Allografts ¢ Bone grafting from another individual (Human ae ; :  donors). Bone is taken from cadavers. Although it loss. Osteocartilaginous grafts are discussed in nasal  can be from living donors, it is more likely to reconstruction in detail.  come from dead individuals ¢ Alloplastic materials used in nasal surgeries are silicone,  : eee Bee led Sue ton eeparalowand Mersilene mesh, porous polyethylene, proplast, alloderm,  * Preparation removes risk of antigenicity etc. The usage depends on the type and size of defects and  ¢ Limited risk of disease transmission can be used alone or along with autogenous grafts.  ¢ Osteoinductive  ° cel standard Zl eNO SED) sone 61.2.3.2 Orbital Deformities [19]  Synthetic Artificial bone substitutes. Constitutes mineral to Aruteseaous bone sate ware catliae considered te beideal  variants organic matrix ratio close to that of normal human °  bone. Grafts not taken from living donors for treatment of orbital floor deformities, but are currently  Xenografts Grafts from species other than humans replaced by alloplastic materials. Silastics are currently  Alloplastic * Strictly a synthetic bone substitute not considered due to reports of post-operative infection.  grafts ¢ Osteoconductive in nature   Produced by recombinant DNA technology.  Consists of human growth factors or morphogenic  proteins    Most commonly used alloplastic materials in orbital  reconstruction:  ¢ Titanium mesh.  e High-density porous  Medpore).    INTRA ORAL:  ¢ CHIN  MANDIBULAR RAMUS  * MAXILLARY TUBEROSITY  * EXOSTOSIS  ¢ BIOLOGICAL DRILLING    ¢ CALCIUM SULPHATE  * CALCIUM PHOSPHATE  * BETA-CALCIUM  TRIPHOSPHATE  * CORAL  HYDROXYAPATITE    * CERAMICS  ¢ BIOACTIVE CRYSTALS  ¢ SYNTHETIC POLYMERS  * COLLAGEN MATRICES  * COMPOSITES  ¢ POLYMER BASED GRAFT  SUBSTITUTES    * BMP-BONE MORPHOGENIC  PROTEINS  ¢ TGF-TRANSFORMING  GROWTH FACTOR  ¢ VEGF-VASCULAR  ENDOTHELIAL  GROWTH FACTOR  ¢ PDF-PLATELET  DERIVED FACTOR    ¢ Orbital floor implants are used by manual adaptation of  implants according to the contour of the damaged site.  However, custom designed implants with computer-  guided surgical planning is best utilised in management  of late deformities as there is time to assess, plan, design  and custom manufacture the precise implants. Orbital  titanium implants can also be manufactured by this  method.    Alloplastic materials have been used in surgeries since  1930s, and newer materials are available since then.  Prime advantages of alloplastic materials are reduced  donor site morbidity, easily usable, good patient compli-  ance and shorter working time compared to autogenous  grafts. Sources and types of graft materials are listed in  Chart 61.3.    Their role in maxillofacial reconstruction is still contro-  versial. These porous alloplastic materials are high-density  polyethylene implants that are very stable and flexible in  nature and also help in new vascular and tissue growth  within. This makes alloplasts an essential commodity in  management of maxillofacial defects and also in  reconstruction.   Alloplastic materials used in the region of defects for  reconstruction are available in various forms like titanium  mesh, porous polyethylene (Medpor) and PEEK (poly ether  ether ketone) which can be customised as needed. Medpore  (stock) can be manipulated and adapted in situ according to  the defect. It is also possible to make custom-made Medpore,  silicone and PEEK with the computer-aided designing. Even  though they are known to produce good clinical outcomes, it  may be predisposed to infection. Careful handling, under-  standing patient’s history and surgical placement are essen-  tial to avoid any complications or to manage any failures.  Medpore along with fat grafting may serve to restore the  contour as well as the volume. These custom-made implants  are widely used in management of defects and deformities as  part of maxillofacial reconstruction. Applications of  MEDPORE are chin augmentation procedures, correcting  congenital deformities and improving aesthetic outcome in    nasal, subnasal, paranasal, malar, orbital, and mandibular  (angle and body) areas. It is essentially suited for midfacial  contouring in patients treated for cleft. The use of these allo-  plastic materials ideally helps to establish three-dimensional  anatomical harmony in correcting defects. Polyether ether  ketone (PEEK) is another valuable alloplastic material that  precedes with advantages similar to that of Medpore Custom-  made patient-specific PEEK implants have proven to offer  excellent facial rehabilitation. The durability and malleable  property of PEEK make it a biomaterial of choice for maxil-  lofacial surgeons with which complex maxillofacial defects  following trauma or neoplastic can be corrected. Often, the  use of alloplastic materials may be an adjunct or combined  with prosthesis to further complete the facial rehabilitation  process.    Traumatic or iatrogenic reasons causing structural or resid-  ual damages are areas of concern during maxillofacial sur-  gery. Important structural damages involving nerve tissues,  salivary gland apparatus and nasolacrimal system should be  identified and best managed during the primary surgery. If  left untreated, secondary or delayed management leads to  further complications. It is the skill of the surgeon to care-  fully carry out the surgery with no or minimal trauma to  adjoining structures, and it is experience that will help to  predict any relative functional damages and manage it  accordingly.    Nerve Injuries: Injuries to the peripheral branches of the tri-  geminal nerve following maxillofacial trauma or surgery  often result in sensory and functional problems. Spontaneous  recovery of inferior alveolar nerve and infraorbital nerve  after facial fractures depends on a number of factors like age,  gender, fracture displacement, site, type of management and  time interval between injury and management. Localisation  and determination of the pattern of injury of trigeminal nerve  are done by careful examination of the neurosensory dys-  function (NSD) of sensory dermatome of trigeminal nerve. It  may be very difficult in establishing the exact cause in sec-  ondary NSD damages. Such residual defects due to injuries  can be from nerve compression due to displaced old fracture  segments, laceration due to fracture components, dislocated  nerve from a displaced fracture, and compression due to soft  tissue oedema or secondary ischemia. Injuries may also be  related to crushing, avulsion and partial or total nerve tran-  section [25-28].    Determining the exact aetiology of post-operative resid-  ual or secondary NSD damage is difficult, and the best way    to manage is assessing the damage during the primary sur-  gery. Accessing and operating the site for correction second-  arily may itself cause further damage if not handled properly.  Nerve grafts can be used in the management of such dam-  ages. It involves microsurgical repair of nerve that requires  reconstruction of any continuity defect using an autogenous  nerve graft (donor site—sural or great auricular nerve).  Microsurgical repair helps in improving the clinical outcome  in such conditions. Nerve allografts have proven to be suc-  cessful in improving the neurosensory recovery. Allografts  are further beneficial as it alleviates the donor site morbidity.  Ichihara et al. suggest the use of alloplastic tubes in short  span nerve defects as artificial nerve guides. However, stud-  ies need to ascertain their use in long span trigeminal nerve  defects. Similar use of autogenous and allogenic grafts is  applicable for facial nerve injury as well. The successful out-  come of grafts depends on the length/size of the defect and  patient factors like age/gender/nutritional status, and it is  also important to address factors like previously irradiated  sites [29-32].    Salivary Gland/Duct Injuries: Trauma, lacerations, deep  injuries and iatrogenic injuries in the parotid region can  result in injuries to the important related structures like the  buccal branches of facial nerve, Stenson’s duct and trans-  verse facial artery and vein. Surgical and non-surgical man-  agement of injuries to the salivary gland or its duct is done to  improve the clinical outcomes. Non-surgical management  includes the use of anti-sialagogues, elastic bandages and  reduced oral intake until the defect heals. Microsurgical  repair may be done to preserve remaining ductal structures  using autologous vein grafts. Reconstruction of the duct is  done using autologous vein grafts like saphenous vein, ante-  brachial vein, facial vein, etc. Alloplastic Gore-Tex has been  used, and the outcome was found to be similar to anastomo-  sis in autologous vein grafts in parotid duct reconstruction.  Gore-Tex tube carries advantages like decreased graft mor-  bidity and shorter operation time. Timely correction of sali-  vary ducts is important to avoid complications like sialocele,  salivary fistula, etc. [33-38].    Nasolacrimal Duct Injury: It is important to reconstruct the  nasolacrimal system if damage is seen following orbital or  midface trauma. It is similar to other ductal and nerve man-  agement. The nasolacrimal duct system can be reconstructed  with autogenous and allogenic grafts. Greater saphenous vein  can be used as autogenic grafts in such cases. Buccal mucous  membrane grafting also shows improved outcomes in remov-  ing obstructions in the ducts. Silicone stent intubation is also  used in the repair of damaged nasolacrimal duct. Primary  management is essential in this condition since delayed man-  agement may be difficult to carry out [39-41].   Future in grafting promises advances in gene therapy, tissue-  engineering, and 3D scaffold. It has created greater perspec-  tive with the inclusion of growth factors, stem cells and  biological scaffolds that will help in production of laboratory-  engineered tissue substitutes in oral and maxillofacial  surgery.    Three-dimensional (3D) computed tomography (CT)  has brought major changes to visualisation, planning  and treatment of maxillofacial defects ever since its  introduction. The scanning and surgical planning soft-  ware have advanced in such a way that a surgeon can  meticulously plan a patient-specific protocol to carry  out procedures effectively. Preformed and custom  printed alloplastic has more accuracy, reduced opera-  tive time and a predictable outcome in management.  However, conventional implants require intraoperative  adaptations and longer duration of operation. All these  have been possible with the advances in reconstructive  surgeries with CAD-CAM (computer-aided design-  computer-aided modelling) software. Such major  advances will lead to further improvement in patient-  specific implants (PSI) in the three-dimensional  management of defects in reconstructive procedures  [23, 24, 42, 43].    Deformities in the maxillofacial bones are due to a variety of  causes like pathology, trauma, infection and congenital dis-  abilities. Residual deformities are such defects that are  observed even after the primary surgical management and  need further cosmetic and functional intervention for an out-  come. The size of the defects in the maxillofacial region may  vary from small alveolar clefts and nasal deformities to  maxilla-mandibulectomy-type defects. Restoration of the  deformities to its closest healthy anatomical structure and  their essential functioning are the primary goals of any re-  intervention procedure.   Any defect (size, shape, position or amount) of the osse-  ous structure can be replaced by reconstructive surgery. The  aim is to replace it with the missing structure, i.e. the bone.  Various types of bone grafts may be used for this purpose.  Correction of soft tissue defects needs a complete under-  standing of the wound healing biology. Likewise, in hard tis-  sue deformities, it is essential to know the bone physiology,  immunology and surgical principles to make the reconstruc-  tion a successful procedure.    Although general rule implies to replace or reconstruct the  lost osseous defect, it is important to evaluate every patient  thoroughly before proceeding with any intervention. Analysis  should include evaluation of hard tissue and associated soft  tissues. When accompanied by soft tissue deformities, it is  important to treat with caution considering the soft tissue  changes over time as well [44].   e Site and size of the defect to be taken into detailed evalu-  ation. Such evaluation is of utmost importance in man-  dibular osseous defects.   ¢ Causes like trauma, gunshot wounds and infection may  result in loss of a portion of the mandible.   ¢ Loss of tissues results in functional and aesthetic con-  cerns. Small deformities may often go unnoticed.   ¢ Loss of a portion of the alveolar process leading to loss of  teeth is a less serious complication.   e Malunion of mandibular fractures can often result in  serious consequences in occlusion among adults and  children. More serious changes may affect the man-  dibular growth in children following condylar  fractures.   ¢ Loss of anterior attachment of the tongue due to tissue  loss causes an airway hazard that needs to be corrected  primarily.   No treatment is often required if the occlusion is satisfac-  tory. Complete fusion of the bony segments to the temporo-    the developing mandibular condyle after trauma or second-  ary infection. In this case, the destruction of the articular  disc allows the contact between the bony fragments of  ascending ramus and the glenoid fossa, finally resulting in  ankylosis. When this occurs in children bilaterally, it shows  reduction in lower third dimension resulting in appearance  called “Bird Face deformity”. This usually results in aes-  thetic and airway concerns, and psychological distur-  bances. Airway disturbances should be viewed with greater  importance. Ankylosis in adults will result in occlusal  abnormalities and difficulty in enunciation of speech and  communication. Sometimes pseudo-ankyloses may also be  observed.   They are fractures with arrested healing that requires fur-  ther surgical treatment for correction. It is considered to  be non-union when a fractured segment is mobile for 4  weeks without treatment or 8 weeks after surgical  treatment.   ¢ Malunion in closed reduction techniques may be identi-  fied after release of maxillo-mandibular fixation.   e Extra-oral approach is the best option as it allows good  visualisation. Transoral approaches may be considered in  indicated cases.   ¢ It is followed by the debridement for removal of any  fibrous tissue, necrotic bone or failed hardware.   ¢ Following this, adequate occlusion and maxillo-  mandibular fixation is achieved. The fracture is reduced,    and then reconstruction plates are fixed with the help of  screws away from the fracture.   ¢ Considering less mineral (even though appearing normal)  content in the site near the fracture, it is recommended to  place screws no closer than 7—10mm.   e Autogenous bone grafting may be used to re-establish  continuity of mandible in areas where the bone contact is  inadequate.   ¢ In younger patients and well-vascularised areas, union of  small gaps is successful.   It can occur in any type of mandibular fracture when  segments heal in improper alignment. Malunion is often  due to inadequately established occlusion, inadequate    Fig. 61.3 Malocclusion following trauma surgery with multiple loss  of teeth in mandible and associated osteonecrosis. Patient managed  with iliac grafting of mandibular osteonecrosis site, followed by implant  rehabilitation and _ vestibuloplasty. Preoperative radiograph. (a)  Panoramic radiograph (b) Cone beam computed tomography scan.   Figs. 61.3, 61.4, 61.5, and 61.6 depicts malocclusion  related management of deformities.   It is often diagnosed with malocclusion and more associated  with rigid internal fixation. Dental models are used to study  and plan the occlusion.   ¢ Revisit of the surgical site may be necessary to correct the  errors due to rigidity.    (Reference for Figs. 61.3, 61.4, 61.5, and 61.6) (http://creativecom-  mons.org/licenses/by/4.0/), Kim SY, Choi YH, Kim YK. Maxillofac  Plast Reconstr Surg. 2018;40(1):27. Published 2018 Oct 15.  doi: 10.1186/s40902-018-0167-z (springer open)    Fig. 61.4 Clinical intra-oral photograph showing. (a) Iliac bone harvesting. (b) Grafting of the harvest iliac bone into the mandible defect   e Study models are used to study the occlusion and plan a  mock surgery.   ¢ Mandible is re-fractured > occlusion is achieved with the  help of a surgical splint > maxillo-mandibular fixation is  obtained — new rigid fixation > occlusion is verified  after the release of maxillo-mandibular fixation.   e Bone grafts may be used to close gaps whenever  necessary.    61.3.2.7. Malunions/Malocclusion and Condylar  Fractures [53-56]  e Majority of condylar fractures when treated “closed” may  develop malunion. However, condylar malunion may not  always cause malocclusion.    ¢ Quality of the functional rehabilitation of the mandible is  an more important factor than the type of treatment  (closed or open).   e No treatment or previous unsuccessful treatment is a  main reason for malocclusion following condylar  fractures.   e Degree of mandibular ramus deformity is essential to  determine the necessity for a re-surgery to correct maloc-  clusion following condylar fracture.   ¢ Minor occlusal discrepancies may be treated with ortho-  dontics, prosthetic rehabilitation, reconstruction and  occlusal adjustments if indicated.   ¢ TMJ reconstruction may be indicated—when the remain-  ing ramus is short with multiple fragments and large  movements are required to correct occlusion.   ¢ Functional therapy can be done up to 3 months for man-  agement of malocclusion.   ¢ Usually as a sequel to malunion, non-union and inade-  quate fixation.   ¢ Incases where the defect is diagnosed early, the mandible  can be approached through the initial surgical wound, the  hardware may be removed, mal union corrected and new  fixation can be placed.   ¢ Orthognathic surgeries in cases of established facial  asymmetries. Surgical splints and model surgeries help in    surgical planning. Asymmetry is corrected, and new  occlusion is verified with new fixation. The procedure  similar to principle treatment. Additional osteotomy may  be required depending on the type of original injury.   Marx and Saunders listed the goals of mandibular recon-  struction in order to consider a grafting procedure successful.  ¢ Restoration of continuity is the key since the mandible is   need to be realigned not only to improve facial aesthetics  but also to restore essential function movements.   ¢ Restoration of alveolar bone is another essential aspect to  aid in the functional rehabilitation of the patient. The pro-  cess of mastication and the efficiency to masticate are  possible only once the necessary alveolar bone height has  been obtained. In patients with osseous defects, this helps  in the placement of a prosthesis.   e Restoration of osseous bulk is vital to provide the required  amount of osseous tissue to withstand forces and perform  normal function. Fracture of the graft area may occur  when the area is too thin, lacking the bulk to withstand  functional forces directed towards the bone.    The midface is a critical zone of the maxillofacial region  concerning both aesthetics and function. Midface includes  structures like the maxilla, palate, orbit, cheek, upper lips,  eyelid and nose. It is often an area that poses a significant  challenge to a maxillofacial surgeon for reconstruction.  Orbit is usually challenging to reconstruct in secondary  setting mainly due to chances of scarring. Due to the dif-  ficulty in obtaining good results in primary surgery, the  nose and auricle are best considered for correction in a  secondary setting. Figure 61.7 shows areas of the  midface.    Along with the reconstruction of the hard tissue, it is  important to correct associated soft tissue defects as well.  Failure to correct the primary deformities may result in  sequelae of defects of the associated soft tissues and end  up in affecting the functional quality of life of the  patients.   ¢ Poor result following primary reconstruction (partial or  complete loss of flap, non-union of bone, oro-cutaneous  fistula)   Treatment planning for midface changes requires careful  planning and knowledge of previous treatments to achieve  the best result.    e Evaluate general status of the patient (age, history of  tobacco, alcohol abuse, nutritional status, and presence of  co-morbidity)    e Accurate assessment of anatomic defects  e Assessment of quality of tissue involved, surrounding tis-  sues and status of scar  e Availability of healthy surrounding tissue  During the workup, it is necessary to eliminate cases of  unresectable conditions like distant metastasis or recurrence  in oncology or non-traumatic cases.   Assessment requires evaluation of surface or volume of  missing tissues. Assessment should include evaluating  defects in the bone, skin, musculature, innervation and  mucosa (Chart 61.4).   Surgical correction in this region varies from prosthetic  replacement to complex microvascular reconstructive  surgeries.   e Secondary free flaps: iliac crest flaps, fibula flaps, sub-  scapular free flaps.   e Microvascular flaps provide adequate and necessary  amount of well-vascularised bone and/or soft tissue aug-  mentation, thereby enabling a better 3D fitting flap and  closure.    ¢ Critical evaluation is to be done in previously irradiated or  operated midfacial defects.   Current methods under development include tissue engi-  neering for ideal regeneration of the tissues in head and neck  defects. Facial transplantation has also paved newer paths  in this field, but indications are restricted.   ¢ Complex defects affecting structures like the nose, orbit  and those which cannot be restored with flap reconstruc-  tion may be managed by maxillofacial prosthesis. Recent  advancements include supporting the prosthesis with den-  tal implants.   e Additional supportive techniques may help to improve the  outcome of a correction in midface re-operative  procedures.   ¢ CT images are useful in designing adequate fronto-orbital  facial contours.   e Free bone grafts for facial contouring are indicated for  upper midface defects. The bone grafts can be obtained  from  calvaria and _ synthetic implants—porous  polyethylene, methyl methacrylate and titanium mesh.  However, it is contraindicated in a previously irradiated  area and in cases of oral cavity communication.   ¢ Combination of titanium mesh and soft tissue may be  helpful to provide support for the globe.   ¢ Liposuction is an excellent alternative technique to fill  certain residual defects following midface reconstruc-  tion. Microvascular flaps may help fill residual flattened  areas.   ¢ Distraction osteogenesis: Mainly indicated in mandibular  repair, it is also used in the repair of minor maxillary bone  defects which cannot be treated with bone flap recon-  struction (refer Chap. 87).   e Implant-supported prosthesis with good osseointegration  is often considered as the best option in oral rehabilita-  tion. Peri-implant hygiene and osteointegration are  important for the success of dental/zygomatic implants in  oral rehabilitation procedures.   e Dental implants are most helpful for oral rehabilitation.  Implants may be placed during the primary reconstructive  procedure or preferably as a secondary procedure.   e Zygomatic implants may also be used when regular alve-  olar bone reconstruction is not possible.   e Implant placement in previously irradiated areas may not  give the best results, and hence it is a contraindication.   e Preoperative photographs (full face, profiles pictures,  frontal and lateral views of occlusion, palate, floor of the  mouth and other required projections).   ¢ Detailed clinical assessment and treatment of other exist-  ing carious and inflammatory conditions of the oral cavity.   ¢ Current imaging and planning techniques: CBCT helps in  3D virtual planning to design flaps and to create 3D mod-  els for planning and mock surgery (61.5).    Open Surgical Immediate Mobilisation Treatment: This is  indicated in conditions where total mobilisation is not pos-  sible. These are cases that are treated after 6 weeks or more  after trauma, or even years later, usually cases where partial  or complete consolidation has already taken place. The  principle of surgical treatment is often the same as in the  treatment of primary maxillary and midface treatments.    Old Fracture Segments: Old fracture segments in the anterior  maxilla can be corrected by techniques described by Wassmund  (1935) and Wunderer (1962) in cases of protruded maxilla. It  is key to observe any scars in the labial vestibule as that may  affect the vasculature to the alveolar process. Wassmund’s  method should be preferred when a scar is present; otherwise,  Wunderer’s method may be followed in which maintenance of  labial blood supply is essential. In contrast, Schuchardt K sug-  gested a single-stage technique which involved an osteotomy  of the lateral alveolar process and relocation to its original  alveolar location [62-64].    Untreated Le Fort I Fractures: An incision may be made at  a point horizontally through lateral and anterior maxillary  sinus walls. Osteotomy is done to ensure that the plates are  placed on both sides of the stable bone region. Line of oste-  otomy does not precisely follow the line of fracture.    Old Le Fort II Fractures [3]: If there’s no cosmetic signifi-  cance or less damage to the nasal region—similar procedure  may be followed. Le Fort II osteotomy is indicated when the  nose has sunken, and the midface is shortened.   In the above scenarios, Le Fort I and II osteotomies may  be done when either occlusion needs to be restored or there  is an aesthetic concern. Bone grafts may be used in the region  of the bridge of the nose below the buttress and also between  pterygoids and the maxillary tuberosity if possible (Figs. 61.8  and 61.9).   ¢ Minor displacements may be corrected with osteotomies,  only if the disturbance along the intermaxillary relation-  ship in the sagittal plane is minimal. Otherwise, it is justi-  fiable to treat with a prosthesis.   ¢ Incase of severe displacements of maxilla which results  in the appearance of a skeletal Class III, the maxilla has to  be surgically replaced to its original place with the help of  bone grafts.   Le Fort HI osteotomy is indicated in old Le Fort III frac-  tures when the deformities may be seen in the entire mid-  face region with dislocations in orbital margins and  zygoma. Unilateral osteotomy may be indicated when  only one side of the face is affected. Occasionally in cases  of comminuted fractures of the midface, a Le Fort I oste-  otomy may be needed to be done along with Le Fort III  osteotomy procedure. This is essential to correct the  occlusion in untreated midface fractures. It may be chal-  lenging to carry out a re-treatment for comminuted mid-  face fractures. Segments may be stabilised separately  considering the complex nature of the fracture. The proce-  dure can be simplified by first mobilising the entire mid-  face complex with Le Fort III osteotomy and then followed  by Le Fort I osteotomy (Figs. 61.12, 61.13, 61.14, 61.15,  and 61.16 shows surgical management of a mid face  deformity by onlay grafting; All images 61.12—61.16 are  from the same patient) (Figs. 61.17, 61.18, and 61.19  shows clinical images of management of post operative  malocclusion; all images 61.17-61.19 are from the same  patient).    Maxillary mobilisation can classified into gradual and immediate repositioning. Gradual repositioning of maxilla & midface complex were opted in cases where  cicatricial fixation had already taken place. Gradual repositioning of midface/maxilla fractures using elastic traction, headframe, roll extension method,  orthopaedic apparatus are mentioned here with respect to the historical perspective of therapeutic options. However, those methods are not current in usage.    * Intermaxillary elastic traction repositioning of untreated  * Elastic traction - Wassmund maxillary fractures  method (Active mobilisation)  * Elastic traction - with headcap  and headframe * Surgical: Open Immediate  * Roll extension with traction reposition of untreated  * Orthopedic apparatus maxillary fractures.    @Association of Oral and Maxillofacial Surgeons of India  Chart 61.5 Historical perspectives of therapeutic options for maxilla and midface correction [3]  Fig.61.8 Schematic diagram   61.3.5 Post-traumatic Hypertelorism cedure may follow as suggested by Tessier et al. (1967).  [3, 44, 65-71] Stereolithographic models are best used for treatment plan-   It is a complication that may arise in fractures of midface approach to correct the deformity, it was further refined  complex when there is a dislocation of one or both orbits. later by Tessier, Converse, Van der Meulen et al., Monasterio    et al. and Marchac et al. They were able to visualise the  bony orbit in two parts with the outer square box containing  the globe and the inner cone housing the optic nerve. It was  established that if these two parts could be separated, the  outer box can be moved without affecting the vision.   ¢ Correction of associated soft tissue defects over the  nose, nasal clefts or even displaced eyebrows    Periorbital area is often a zone of interest in the midface  region from a functional and aesthetic point of view. An  imbalance in this region could result in aesthetic concern and  altered vision. This can be due to malunion of the fracture of  the zygomatic complex. Any untreated fracture for longer  than /0 weeks is considered to be an old fracture and results    in malunion—a stage at which a procedure needs to be done  to correct any deformity.    Soft tissue damage like a torn lateral canthal ligament,  malpositioned zygomatic bone, zygomatic arch or fragments  of the orbital arm may result in an asymmetry of the lateral  midface. Corrective surgeries may be required in case of a  destroyed orbital bone as well. More often, patients visit the  surgeon for aesthetic reasons. It may be often difficult to cor-  rect aesthetics when it involves post-traumatic deformities in  the malar prominences (Table 61.3).    ¢ Dislocated eyeball: Usually occurs as a sequel to zygo-  matic fractures, and slight dislocation may be seen after  primary treatment. Displaced orbital floor due to enlarge-  ment of the socket or the loss of the orbital content due to    Fig.61.11 Schematic diagram showing post-operative following combined Le Fort I and Le fort III. Defects as a result of repositioning shaded  as brown are area to be filled with bone graft    Fig. 61.12 Midface deformities showing residual deformities. (a) pre-  operative extra-oral photograph showing facial asymmetry, depressed  malar prominence (right side), and incompetent lips. (b) Post-operative  extra-oral photograph. (Reference for Figs. 61.12, 61.13, 61.14, 61.15,    Fig.61.13 (a) Preoperative  intra-oral photograph showed  deranged occlusion with right  anterolateral open bite. (b)  Post-operative intra-oral  photograph    and 61.16: Ranganath K, Hemanth Kumar HR. The correction of post-  traumatic pan facial residual deformity. J Maxillofac Oral Surg.  2011;10(1):20-24. https://doi.org/10.1007/s12663-010-0088-6) springer  publishers    Fig.61.16 (a) Onlay graft positioned on the patient. (b) Onlay graft plated to the maxilla    Fig. 61.17 Patient complains of open bite, malocclusion, deviation of occlusion after maxillofacial fracture management: a retrospective case  maxilla and TMJ tenderness after trauma surgery. Preoperative OPG _ study.” Maxillofacial plastic and reconstructive surgery vol. 40,1 27. 15  showing malunion in maxilla and malocclusion. (Reference for Oct. 2018, https://doi.org/10.1186/s40902-018-0167-z. (http://creative-  Figs. 61.17, 61.18, and 61.19: Kim, Sang-Yun et al. “Post-operative mal- | commons.org/licenses/by/4.0/), springer open    Fig.61.18 Photograph during the operation. (a) Shows severe malocclusion before second operation. Arch bar placed for intermaxillary fixation.  (b) Fracture site exposed, malunion segments detected    Fig.61.19 Le fort I osteotomy done under general anaesthesia to resolve malunion and malocclusion. TMJ pain resolved following the treatment.  (a) Post-operative (1 month) photograph showing resolution of malocclusion. (b) OPG after | month. (¢) OPG 1| year after operation    soft tissue displacement or necrosis may result in enoph-  thalmos and/or downward displacement of the globe.   ¢ Diplopia: Usually due to severe dislocation of the eyeball,  but severe diplopia may more likely occur as a conse-  quence to trauma to the cranial nerves, scarring of the  extraocular muscles or prolapse and entrapment of orbital  soft tissue. Waiting period before re-treatment of diplopia  neural and muscle damage is at least 12 months and 15  months, respectively, to observe if the diplopia subsides.  Diplopia is differentiated into heterotropia and heteropho-  ria. While sometimes heterophoria may not even need a  correction, in certain cases of severe heterotropia, the  patient is advised to maintain a titled head position to  avoid any double vision. Sometimes double vision may  persist even after the fracture has been corrected.   ¢ Paraesthesia of the distributing area due to crushing or tear-  ing of the nerve within the infraorbital canal or foramen.  Recovery of the nerve by itself may take at least 1 year.   ¢ Limited mandibular movements are caused due to a  depressed zygoma impinging on the coronoid process of  the mandible, restricting the free excursion of the coronoid  process. Patient complains of difficulty to open the mouth,  and some cases of difficulty to close the mouth may be due  to an open mouth during the blow to the zygomatic  complex.   ¢ Pseudoarthrosis between the coronoid process and tem-  poral process of the zygomatic bone may occur rarely in  old untreated cases [72].   ¢ Aesthetically unacceptable asymmetry of the orbital rims.  Pathological difference between the two malar promi-  nences more than 5mm.   ¢ Diplopia caused due to downward displacement (more  than 3mm) of the eyeball due to orbital floor displacement  and not primarily due to neural or muscle damage.   Tomograms To examine orbital floor, space between coronoid  process and zygomatic arch   ¢ Paraesthesia of the orbital nerve after at least 12 months  of post-surgical repositioning of bone fragments.   ¢ Depression of zygomatic arch impinging the coronoid  process that is radiographically evident in causing limited  mandibular movement.  Surgical correction of traumatic zygomatic complex frac-   Surgical approach is decided once the operative procedure  has been finalised. Common approaches include [3]:   e Failed surgery due to insufficient fixation of the re-  fractured site or failure due to the implanted materials.   ¢ Untreated pre-existing chronic sinusitis may result in an  orbital abscess or phlegmon.    Rotated and displaced zygomatic bone leads to separation  of the structures from its normal articulation with the greater  wing of the sphenoid and maxilla. A substantial increase in  the volume of the orbital cavity is accompanied by fissures  along the floor and lateral wall of the orbit. Also, naso-  ethmoidal fractures can result in canthal distortion and mal-    position. Telecanthus and canthal height distortion can be menting the sub-periosteum of the anterior orbital wall,   difficult to correct if there is a significant loss of soft and hard anterior to the axis of the globe. This technique helps to pro-   tissue. duce superior movement of the eyeball but does not correct  Any excess or deficiency in the horizontal position of the enophthalmos even with the overall decrease in orbital vol-   globe is called dystopia and is easier to correct. Inferior dis- ume [5].    Onlays placed through Osteotomies done through  Intra-oral incision extra oral incision.    rim During this, the orbital floor needs to be observed for any adhesions  Paraesthesia ¢ Persistent paraesthesia is an Infra orbital foramen is widened to free the nerve  indication for surgery When only paraesthesia is present—can be accessed through an intra oral approach  When additional exploration of the infra orbital canal is required—tlower eyelid  incision is indicated  Depressed ¢ Hindering the coronoid process’ _—_Refracture, reposition and wire fixation  Zygomatic arch free excursion Surgical Approach: Curvilinear, pre-auricular and/or lateral eyebrow incision  Older surgical approach: Removal of coronoid process  Complete Zygoma ¢ Depressed malar prominence, ¢ Treated with osteotomy  Dislocation caudally displaced eyeball and * Camouflage surgery as a second option  diplopia ¢ Lateral eyebrow incision and infra-orbital incision to explore the zygomatic    complex and detach from the frontozygomatic suture at the inferior orbital  margin, inferior and lateral walls of the orbit, and the zygomatic arch (if  necessary)  Reposition the segments  Fixation of the fragment is further assured by placing bone graft in the gap in  lateral or inferior orbital rim  ¢ Orbital Floor is finally covered with lyophilised dura. Procedure is done to ensure  good support to the malar bone and orbital floor  To prevent post-operative relapse | Over compensate the pre-operative displacement to a certain extent  after above surgery  If downward displacement of Free transplant of lyophilized dura could be an option  globe is not completely resolved  after the surgery.    Enophthalmos: [5]  Managing post-traumatic secondary enophthalmos involves  reducing the volume of orbital cavity posterior to the globe  axis. The three-dimensional anatomy of both external and  internal structures of the bony orbit should be restored effi-  ciently by refracturing and rearticulating the skeletal frame-  work (including zygomatic bone).   e The zygomatic bone may be accessed by complete expo-  sure using surgical techniques to free the bone and also to  establish the correct alignment.   e The zygomaticofrontal suture and the zygomatic arch are  exposed through the coronal flap, and facial and muscular  connections including the masseter muscle are released.   ¢ Inferior orbital rim and orbital floor are exposed through a  lower eyelid incision. Upper lip gingivobuccal incision is  done to uncover the zygomatico-maxillary articulation.   e Bony cuts mimicking zygomatic complex fracture are  made with a reciprocating bone saw.   e The zygomatic bone is freed and then replaced into the  new position with rigid fixation. Necessary bone grafting  needs to be done to close the gaps and also to augment the  orbital volume.   ¢ The globe should be left slightly exophthalmic (1-2 mm).  If an autologous bone is used in augmenting the orbital  volume, this exophthalmos is left behind expecting  resorption over the next few months. However, this may  be difficult to achieve in cases of excessive scarring.   e Placement of the graft plays a very important role as  improper placement of grafts, or displacement into the  intramuscular cone can result in dysfunction of the extra-  ocular muscles or damage/injure the optic nerve.   e Management of complication: Creating safe pockets for  the graft by carefully dissecting off the periorbita from the  underlying bone. The grafts may be placed external to the  extraocular muscles if the periorbita had been disrupted  from previous trauma.   ¢ Enophthalmos and diplopia may worsen further due to  scarring or displacement of the implant. However, post-  operatively globe position may moderately improve and  is often long-lasting [5, 72—74].   e Pressure from grafts posterior to the globe may result in  retinal folds and ischemia.   ¢ Corrected using medial orbital osteotomy by positioning  the tendon and the overlying soft tissue medially.   ¢ Bone cuts that are made along the fracture lines (typical  as in nasoethmoid complex fractures) help to free bone  segment that inserts into the point of the tendon, followed  by medially relocating the bone to its normal anatomical  location.   ¢ Rigid fixation of the bone is done to the surrounding bone  over the maxilla and inferomedial forehead. Autologous  bone grafts may be used to replace missing bone segments.    Residual nasal deformities occur as a consequence of the dis-  placement of bony and cartilaginous components of the nasal  skeleton. The basic anatomy of the nasal skeleton includes the  nasal bone and the cartilaginous part of the nasal septum. The  frontal process forms the lateral walls, and the vomer forms  the osseous part of the nasal septum. The nose is the most  commonly traumatised area due to its prominent central loca-  tion and its elevation from the frontal facial plane. However,  secondary deformities to nasal trauma are not rare [3].   The patient needs to be aware and educated on the options  for a secondary rhinoplasty to correct the residual nasal  deformities as the pathology may concern the functional and    e The intensity of the trauma is relative to the type of  deformity that may follow.   ¢ Initial low intensity trauma — nasal tip may become  malpositioned. There is an evident inward rotation  of the lower portion and an upward-outward rota-  tion of the upper portion. This results in a depressed  supra tip and a small cephalic hump.   e Degree of angulation and contour of frontal and the nasal  margins at nasofrontal angle   It is important to evaluate the injury as it may be related   e Superior fronto-ethmoidal complex  Residual deformities may fall in the following groups and   ¢ Fractures of > nasal bone, frontal process of the maxilla,  septal cartilage — untreated and/or inadequately treated  fractures, displaced fragment — resorption associated  with fibrous union/malunion with excess callus  formation.   e Malunion depends on the direction and point of contact of  the blow of the original injury.   ¢ Residual callus and subsequent deformity will be evident  following fracture of bony or cartilaginous structures or  both tissues.   e Force directed from the lateral aspect > deviation of the  bridge and lateral wall to the opposite side.   e Nose deviated towards one side or crushed inwards or  both deformities together.   e When seen from the front, the bridge and the dorsum of  the nose may appear to be in a straight line, but the tip and  the base of the septum are deviated, also leading to defor-  mation of the nasal orifice.   e Tip of nose may often be straight but is angulated when  the cartilaginous dorsum is displaced.   e Dissection is done by Separating or freeing the external  investing tissues > elevation of mucous membrane that  lines the nasal fossae.   e Dissection includes separation of underlying soft tissues  and separation of mucosa.   ¢ Bony and cartilaginous structures freed from the external  and internal harvesting tissues.   e Osteotomies are done to reduce the displacement of the  nasal bridge and dorsum — lateral and median osteotomy.   ¢ Immobilisation aids in maintaining the fragments in posi-  tion during the union. Careful immobilisation is done  internally and externally.   e This deformity is best treated with placement of a bone  graft in the region of depression of the bone.   e Vertical columella incision: Gives good exposure but may  leave scars.   e¢ Accombined incision with both internal and external inci-  sion gives best exposure and leaves a less obvious trans-  nasal scar in the anterior one-third of columella. This is  almost invisible in the upright position due to its presence  in a “dead angle”.    ¢ Surgical steps involve preparation of bony bed at receptor  site and preparation of bone graft for placement.   e Stabilisation of bone graft by firm fixation in median, ver-  tical and sagittal planes. Ensure the maintenance of  columnar support.   ¢ Reduce false or relative prominence by resection of upper  half of the nasal crest. Nasal profile is converted to being  straight. This might increase the width of the upper half of  the nasal crest for which osteotomy of lateral walls may  be essential. This concept is to be applied when adequate  nasal bone is available to produce a healthy and aesthetic  profile.   ¢ The other concept involves the placement of a cartilagi-  nous graft to cover the depression. Fixation may however  be difficult in this scenario.    61.3.8.5 Naso-Orbital Deformities [3]  Deformities not only involving the nasal pyramid but also  affecting the ethmoid and maxillary components.   ¢ Deformities may extend into the frontal process of the  maxilla and the two orbital plates of ethmoid bone (which  support the nasal bones).   ¢ Due to the complex anatomy of this region, various com-  binations in deformities, fracture pattern, injury and  pathology may be seen.   e Serves as a point of insertion for the medial palpebral  ligament in the anterior crest  Ethmoid bone—   ¢ Continues posteriorly as the orbital plate which forms the  medial wall of the orbit.   ¢ Contributes to the formation of the posterior part of the  nasal septum.   Due to displacement of frontal processes of the maxillae  outwards and backwards   Due to malunion of a comminuted type of fracture.  Displacement of medial canthus—   External displacement may produce telecanthus.  Anterior displacement will further increase in obliteration  of the orbito-nasal angle.   Dystopias are due to the bony fragments impinging on the  tissues and causing rupture of the medial canthal ligament,  avulsion of the ligament and displacement of frontal pro-  cess of maxilla which houses the medial canthal ligament.  Lacrimal passages—   The lacrimal canal is blocked due to discontinuity in  nasolacrimal apparatus. Bony fragments of comminuted  fractures may cause tearing of the lacrimal sac. This may  result in epiphora.   Blockage caused by nasal septum may further be accentu-  ated by displacement of anterior cartilaginous part of the  nasal septum.   e Nasal reconstruction must be carried out while cor-  recting the above mentioned during the same  procedure.    Reconstitution of the nasal base is the basic procedure in  reconstruction of the nasal pyramid. It has to be supported  by a solid base.   Base has to be aesthetically appealing, smooth, regular  and well proportioned.   Reconstitution of the naso-orbital angle is essential.  Symmetrical placement of the two medial canthi is neces-  sary. Any asymmetry can affect the appearance of the nose.  Approach to the lacrimal passages may be obtained by  dividing the medial canthal ligament that can be reat-  tached later.   e Any deviation of the nasal septum negatively influences  nasal reconstruction.   Deformities due to secondary post-traumatic lesions involv-  ing not only the nasal pyramid but also the nasal base and  area of the frontal bone. Concentration of injuries at the  nasofrontal angle is proportionate to the degree of violence  encountered, thereby resulting in fractures and displacement  of tissues.   ¢ Injury in this zone affects the brain and the meninges.   ¢ Deformity in the continuity of bone > herniation of the  brain and meninges.   ¢ Greater degree of depression is relative to the retru-  sion or displacement of middle frontal segment poste-  riorly, extending above the orbits as far as the bridge  of nose.   ¢ Morphological and functional defects should be corrected  to avoid any vital injury in the future.   ¢ Incase of depression of the nasal crest and deformities  involving only the anterior wall of sinus, onlay bone graft  is essential to augment the defect.   ¢ Grossly deranged sinus must be treated first and then fol-  lowed by nasal reconstruction.   ¢ Grafting is not enough when deformities involve the infe-  rior wall/floor and/or posterior wall as it carries the risk of  damaging the sinus, brain and meninges.    The principles of the management of nasofrontal  deformities in delayed conditions are similar to man-  aging post-traumatic nasofrontal deformities but  should be done with caution and must address associ-  ated complications seen at the stage of delayed man-  agement. In case of nasofrontal deformities, it is  important to address post-traumatic dehiscence of  frontal sinus wall in delayed management cases.  Certain degree of bone loss due to resorption is seen  during the post-traumatic phase, and this may  increase when the management is delayed. Hence, in  such cases it is important to be cautious in resection  of minimal tissue of the posterior wall, and it needs to  be carefully performed. Reconstruction of the ante-  rior wall with bone grafts may be done, also includ-  ing the orbital roof and the ethmoidal region if  necessary [3].   Deformities involving the nasal bony mass are caused due to  greater degree of force. The impact may extend as far as the eth-  moid bone which forms the upper wall/roof in the posterior part.   ¢ Fractures lines extending from the front, passing behind  and across the nasal spine and extending into the cribri-  form plate   ¢ Clinically, it may be similar to the deformities involving  nasofrontal fractures. A mere extension into the cribriform  plate does not increase the severity of the deformity. Features  may differ based on the involvement of anterior wall.   ¢ The meningeal tear is always predisposed with long-term  risk of leak (even after the leakage has dried) due to lack  in quality of scar tissue and increased permeability of the  malunited callus.   e Surgery may be carried out by combined neurosurgical  and maxillofacial teams.   ¢ Meningeal tear repair can be managed by trans-ethmoidal  (low level) approach. However, trans-frontal approach is  considered to be safer and effective.   e Sinus-associated lesions should be managed along with  nasal reconstruction procedure.   ¢ The principles of the management of naso-fronto-  ethmoidal deformities in delayed conditions are similar to  managing post-traumatic naso-fronto-ethmoidal deformi-  ties or naso-orbito-ethomoidal complex fractures but  should be done with caution, addressing associated com-  plications seen at the stage of delayed management.    61.3.8.9 Delayed Management of Orbital  Hypertelorism and Naso-Orbito-  Ethmoidal (NOE) Fractures [73, 75-77]  Acute trauma in the naso-orbito-ethomoidal region could  result in chronic orbital and naso-orbital deformities. It is  important to be aware of the acute injury to correct the defor-    mity that will be established later. Secondary late corrections  in cases of severe orbital hypertelorism may be very difficult  to correct. The severity of orbital hypertelorism can be  assessed with the help of Tessier score.    Traumatic orbital hypertelorism due to NOE complex  fractures  Goals of management:   ¢ Coronal approach gives the most predictable access and  visualisation for the surgeon.   ¢ Frontal sinus should also be evaluated and operated at this  stage.   ¢ Reconstruction should be considered in the following  order starting first with cranial base, frontal region  and outer orbital zone, followed by fixation of the  orbital rim and frontonasal buttress. Grafts and plates  may be used to restore the nasal dorsum and nasal  projection.   e Itis then followed by repositioning and fixation of the  mini-plate in the medial orbital wall and medial can-  thal tendon. Mesh and trans-nasal wiring may be  used for repositioning the displaced medial canthal  tendon.   e Jt is important to establish a good frontonasal angle and  nasal projection to have good aesthetic outcome.  Deformity could result in poor aesthetics when there is  poor frontonasal angle and poor nasal projection along  with orbital hypertelorism.    61.3.8.10 Secondary or Delayed Management  of Orbital Hypertelorism Associated  with NOE Complex Fractures [75-77]   e Acute management of chronic long-standing deformities  is essential. It is very difficult to correct severe orbital  hypertelorism, especially in cases which includes intra-  cranial osteotomies. Such cases are associated with    increased post-operative morbidities. Subcranial osteoto-  mies may be opted in milder cases.   e Aesthetic and functional outcomes in late correction  may not be satisfying, and hence the best strategy is  to repair the deformities as early as possible follow-    ¢ Repair and reconstruction of nasal deformities are often  challenging and technique sensitive for the surgical team  (maxillofacial and neurosurgical). It is emotionally and  psychologically challenging for the patients as well.  Hence, it is essential to identify the pitfalls and carefully  carry out the surgical treatment plan. Sometimes, further  revision may be necessary even with the best planned sur-  gical procedures. Therefore, it is important for the sur-  geon and the patient to understand the limitations of the  available surgical techniques.    Management of Post-oncological Deformities:  Post-oncological deformities here refer to the soft tissue and  hard tissue defects that may be encountered following a pri-  mary treatment. Unlike a primary cosmetic therapy, predict-  ing the result of an oncological treatment is often more  technique sensitive and should be considerate in establishing  the overall physical and mental well-being of the patient.  Management of deformities should also aim at a comprehen-  sive functional, aesthetic and social well-being of the patient.   Reconstruction of soft tissue and hard tissue structures fol-  lowing trauma or oncological surgical therapy is primarily essen-  tial. Correction of the residual deformities should be carried out  along with the principles of reconstructive management.    We have already discussed in detail the use of above  methods in management of traumatic residual deformities in  this chapter.   Recurrences, untreated tumours and metastasis which are  considered to be residual in nature after primary manage-  ment are not considered under management of post-  oncological deformities. It is important for the surgeons to be  more accurate with the surgical margins when surgically  operating malignancies. Any re-surgical procedure for recur-  rence or deformities is often challenging due to factors like  previously irradiated areas, previously operated surgical  field, under nourished status due to the pre-existing malig-  nant condition and also due minimal surgical options for  such patients.   Residual deformities associated with post-oncosurgery  results in external facial disfigurement/defects, intra-oral  defects and also changes that may affect certain functions.  These deformities are often relative to structures which were  primarily involved and their corresponding functional defor-  mities. Deformities occurring following surgical treatment  of head and neck oncology usually require reconstruction  procedures as the complete removal of tumours with margins  may involve increased loss of soft or hard tissues.    Post-oncosurgical defects of the lip are often seen with loss  of tissues. Management of such defects is usually considered  according to the size of the defects. Secondary deformities of  the lower lip after reconstruction are described in (Table 61.5),  and they need to be treated accordingly with cosmetic sur-  geries. Lip reconstruction is discussed in soft Tissue recon-  struction chap. 86.    61.4.2 Management of Intra-oral Defects  Involving Floor of the Mouth  and Alveolar Ridge Tumours    Defects in these regions are relative to the size of tissues lost  and may be corrected with augmentation and reconstruction  procedures.   ¢ Correction of small intra-oral defects is best done with  primary closure in the buccal and tongue region, but  scar contracture is seen with grafting. Closure by sec-  ondary intention can be done in alveolar and hard pal-  ate defects where the scar contracture is insignificant  [84].   ¢ Correction of large intra-oral defects using free flaps is  considered ideal in reconstruction procedures [84-86].   e Advanced large defects may be seen in cases which  require large resection of tissues, as in cases of advanced  tumours which may include cortical or segmental man-  dibulectomy, composite resections, and glossectomy  (total/sub-total) procedure. These defects may also  involve the lip or skin of the lower third of the face when  tumour extends anteriorly [86]. Hemi- or partial loss of  mandible may result in severe functional or psychologi-  cal morbidity for the patients. The loss of anterior man-  dible results in a defect called as “Andy-Gump”  deformity [87]. En bloc resection is best reconstructed  with regional free tissue transfer or free flaps. Bony  defects are managed with osteocutaneous free flap or  with free tissue transfer.   e Soft palate defects cause velopharyngeal incompetency  resulting in inability to seal the oropharyngeal and naso-  pharyngeal cavity during speech and deglutition.   ¢ Rhinolalia aperta is caused due to small soft palate  defects leading to change in resonance of voice as a result  of air escape due to incompetent velum.   ¢ Smaller defects are best closed primarily or along with a  split-thickness skin graft.   ¢ Radial forearm flaps are used in cases following surgical  ablation of soft palate and tonsillar defects.    ¢ Large or extensive palatomaxillary defects are managed  with obturator prosthesis or with vascularised osteocuta-  neous free flaps.   ¢ Large defects are treated with myocutaneous flaps (rectus  or pectoral major flaps and fasciocutaneous flaps)    e Primary closure with/without split thickness skin graft is  used for closure of small defects. Free flap reconstruction  is necessary for large defects.    The primary goal in surgical management of oral tumours is  to gain surgical access for assessment and visualisation of  margins and anatomic relations for resecting the tumours.  Surgical margins are vital in establishing a tumour-free zone.  Although it is important to have a follow-up on recurrence of  tumours and metastasis, it is the complex nature of the oral  cavity and head and neck anatomy that requires careful yet  skilful management of the adjacent normal tissues by proper  closure and post-operative management.   The goal earlier was to achieve access to the tumours, but  now it also involves incisions that will facilitate an aesthetic  access to the pathology. Increased incidence of dehiscence and  unaesthetic scar formation are common in neck incisions (with  trifurcation extensions) that do not lie along the natural skin  creases. Irradiated areas may cause worsening of scar appear-  ance, or even superficial necrosis may occur. Inadequate,  delayed and infected tracheostomy may also result in an  unaesthetic tracheostomy scar formation. Prevention of unaes-  thetic scars can be done by careful tissue handling. It is also  essential to protect the skin from additional trauma due to trac-  tion, tension or electrocautery. Flaps with adequate vascularity  further help to minimise the chances of unaesthetic scars.  Following access through the lip to certain tumours in the oral  cavity, the site requires to be exactly oriented and aligned with  the vermilion lip border, as well as interdigitating orbicularis  oris muscle, re-orienting lip skin and oral mucosa to replicate  lip competence, aesthetics and function [92-97].    Even though reconstruction of maxillectomy defects is an  option, maxillary defects can also be corrected with pros-  thetic obturators. Maxillary obturator provides adequate  structural support to preserve speech, swallowing and essen-  tial mastication. Clinically, a good obturator can be fabri-  cated only by the skills of a good prosthodontist [98].   It is important to evaluate any history that may contribute  to poor wound healing and also lead to post-operative wound  dehiscence and compromised flap vascularity resulting in  improper scarring.    Surgical procedure involving the upper aerodigestive tract  through neck incision may lead to fistula formation as a  result of salivary leakage.  The formation of fistulas is contributed majorly due to:  ¢ Incision design  ¢ Tumour type  ¢ Tumour stage  ¢ Improper surgical site management  ¢ History of operative site  ¢ Physical and nutritional status of patient   e Effect of radiation on surgical wound closure: Radiation  dose and timing play an important role in delayed wound  healing, formation of fistula and dehiscence.   ¢ Occurs post-surgery as early as 1 week and somewhere  between 3 and 4weeks in late cases of fistula formation.  Persistent fistulas are present for more than | month.   ¢ Inflamed and indurated areas of skin that facilitate the  drainage.   ¢ Early assessment of fistula can help to explore the surgical  wound and aid in directing saliva from vital structures.   e Site may be explored, irrigated and closed. This is fol-  lowed by antimicrobial therapy and _ nutritional  support.   ¢ Persistent fistulas are managed with excision of the fistu-  lous tract with closure of oral mucosa and/or skin.    e Hardware failure due to infection can be managed with  local debridement, removal/replacement of existing failed  hardware and closure with local and regional flaps.   ¢ Management can be combined with anti-cholinergic med-  ications to decrease salivary flow if necessary and only if  indicated.   Iatrogenic injury may cause “shoulder syndrome’, for which  physical therapy may help to improve the functional out-  come. Pain, weakness of muscles, restrained shoulder move-  ment, deformity of the upper extremity and inability to  abduct upper extremity above 90degress occur due to dener-  vation of trapezius muscle [91, 92, 102, 103].   Iatrogenic damage causes paralysis of ipsilateral diaphragm.  It may even result in long-term pulmonary complications.  Such damage can be prevented by limiting surgical dissec-  tion to the layer superficial to pre-vertebral fascia and thereby  prevent injury to nerve [92, 101, 104].   e Jatrogenic damage to both the nerves is possible during  head and neck dissection. This is aggravated with damage  to lingual nerve during excision of tongue and floor of the  mouth. Hypoglossal and lingual nerves are often preserved  unless there is extensive neural invasion of the tumour.   ¢ Hypoglossal nerve dysfunction/damage causes deviation  of tongue to ipsilateral side of injury, tongue biting, dys-  arthria and difficulty in mastication and deglutition.  Bilateral nerve injury may result in upper airway obstruc-  tion when the patient is in supine position. Atrophy of  tongue muscles may also be observed.   ¢ Damage to lingual nerve may cause ipsilateral loss of sen-  sation, further impacting mastication, speech and swal-  lowing. Injury to tongue during speech and mastication  may also be observed.    ¢ Rehabilitation by physical therapy is often useful for  improving the speech and swallowing.    61.4.6.4 Vagus Nerve, Recurrent  Laryngeal Nerve and Superior  Laryngeal Nerve [91]   ¢ Injury to these nerves may occur during dissection around  the carotid sheath.   e Injury to recurrent laryngeal nerve causes unilateral vocal  cord paralysis. The damage is usually compensated by the  intact contralateral vocal cord. Mild hoarseness is experi-  enced by the patient. Upper airway obstruction is seen  with bilateral injury.   ¢ Injury to branches of superior laryngeal nerve occurs due to  dissection around the superior thyroid branch of external  carotid artery. The following changes may be associated:   Damage or disruption to the sympathetic trunk can result in  ipsilateral Horner’s syndrome. Careful evaluation is neces-  sary to diagnose Horner’s syndrome due to damage of nerve  fibres, and it involves the following:   e Altered mobility of corner of the mouth as a result of dis-  ruption in innervation to orbicular oris and depressor  anguli oris.    Management:  Careful design and incision considering the anatomic  location of the nerve during flap elevation help to prevent    iatrogenic injuries and resultant deformities. It may take  several months for neurosensory recovery when the neu-  rologic injury is due to traction and not due to  severance.    Recent trend in oral surgery includes the use of an endo-  scope to facilitate oral and maxillofacial procedures.  Endoscopy techniques can be used in diagnosis and for  treatment with minimal complications in many oral and  maxillofacial surgical procedures like TMJ disorders,  pathologies of jaw, nasal deformities, trauma and aesthetic  procedures. The techniques and applications of endoscopy  in oral and maxillofacial surgery are explained in detail  elsewhere in this book. The advantages and applications of  endoscopy-assisted maxillofacial surgical procedures make  its usage a favourite option for maxillofacial surgeons.  Minimal complications, good success rates and its effi-  ciency make endoscopy-assisted procedures a _ viable  option.   The following are the best-known applications of endos-  copy currently in oral and maxillofacial surgery:  e Trauma  ¢ Orthognathic deformities  ¢ Obstructive salivary gland pathology  e Maxillary sinus surgery  e Trigeminal nerve injury  ¢ Temporomandibular disorders  e Nasal deformities  e Trauma    Endoscopy-assisted minimally invasive technique is used  in traumatic deformities like the following:    Orbital Floor Fracture: Requires trans antral approach. Care  should be taken to protect the intraorbital contents like mus-  culature, periorbita and optic nerve. Intraoperative condi-  tions may necessitate the need for an additional periorbital  approach during the surgery.    Mandibular Angle Fracture: Here, endoscopy can be used to  fix the mandible with the superior and inferior plate with the  best approximation possible. Endoscopic reduction helps in  complete visualisation of the entire fracture line with inclu-  sion of the inferior border. Management with endoscopy-  assisted surgery also reduces the risk of facial nerve injury. A  single transbuccal trocar technique is used for positioning    and fixation of the plates with easy visualisation of the frac-  ture line. Some surgeons prefer a locking cannula for the pre-  cise placement of the fixation hardware. Endoscope is then  used to confirm proper fixation and reduction, and it is then  closed. Endoscope also aids in appropriate documentation of  the procedure.    Sub-condylar Fractures: (Refer Chap. 54 on endoscopic  approach for treatment of condylar fractures of mandible)  Endoscopy can be applied in management of sub-condylar  fractures by open technique, reducing risks of scars, fistula  formation and facial nerve injury. Extra-oral and transoral  approach may also be used. Although the procedure is tech-  nique sensitive, it is proposed with advantages of improved  visualisation, magnified field of view, less trauma to tissues,  less bleeding, better patient compliance, good reduction and  decreased post-operative complications.    Frontal Sinus Fractures: Endoscopy in the management of  frontal sinus fractures helps to avoid large incisions and its  associated complications like alopecia, paraesthesia, scar-  ring, nerve injury, etc. It helps in better visualisation of sinus  wall fractures, nasofrontal duct and the posterior wall of  sinus.    ¢ The use of endoscopy in orthognathic surgery helps to  visualise aspects of the osteotomy so as to improve the  efficiency of the surgical outcome.   ¢ Best application of endoscopy in salivary gland patholo-  gies is the usage of sialoendoscopy in the diagnosis and  treatment of salivary gland/ductal pathologies in a non-  invasive manner.   ¢ TMJ arthroscopy is another area that has gained greater  attention.   ¢ Endoscopy is also best utilised in removal of foreign bod-  ies from the cranio-maxillofacial region as it allows visu-  alisation of anatomical structures without extensive  incisions.    Endoscopy in nasal deformities: is a developing concept,  and there has been an increase in its extensive usage in sinus  endoscopic surgeries. The use of endoscope in correction of  septal deformities like deviation, aids in better visualisation  of the target site and reduced time of the procedure. The pri-  mary advantages are improved field of view, reduced mor-  bidity, decreased post-operative swelling and more accuracy  in surgical procedure. Endoscopy in nasal corrections is very  essential in cases that have gone for prior septal cartilage  resection, reducing the need for repeated incisions or extent  of dissection. Studies also suggest lesser post-operative  symptoms in endoscopic-assisted nasal septal corrective sur-  geries [107].    Careful planning, eminent skills and excellent knowledge of  the clinical anatomy are of utmost importance in carrying out  secondary corrective procedures in treating residual defor-  mities following trauma or oncological procedures. It is the  skill of the surgeon to predict the functional and aesthetic  outcome of the treatment so as to facilitate a proper treat-  ment planning. It is also the role of the surgeon to educate the  patient about the condition and options available for the cor-  rection, to provide the best possible outcome. It is recom-  mended that surgeons use available imaging techniques  (routine X-rays, CT scans, CBCT, etc.) in their treatment  plans and also make best usage of the current trends in 3D  models and visual planning software in treatment planning.  The use of CAD/CAM-designed patient-specific alloplastic  (e.g. Medpore, PEEK) implants should be considered in sur-  gical management. Treatment plan should often accommo-  date recommendations from other specialities that may be a  part of the surgical team.   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If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.   There is an accepted concept of triple complex involving  both joints and intact dentition forming an integrated system  which is carefully monitored by an arthrokinetic reflex mus-  cular activity to ensure a controlled and stable pattern of  painless mandibular movement. A disturbance in the co-  ordinated activity of this musculature arising from malocclu-  sion often accentuated by psychological factors inducing  neuromuscular tension forms the basis for majority of prob-  lems involving temporomandibular joint (TMJ)  dysfunction.   There is a large pool of evidence that clearly shows that  mind and body are not independently functioning entities but  closely interrelated in all aspects of pain direction, detection  and perception. TMJ disorders is an umbrella term referring  to a classification of musculoskeletal disorders impacting the  masticatory muscles and/or the TMJ and is usually subdi-  vided into three main categories. Box 62.1 enumerates the  three categories of musculoskeletal disorders, often clubbed  as TMJ disorders.    Box 62.1 Subcategories of TMJ Disorders (TMDs)  1. Myofascial pain disorder    M. F. Baig (2)  Department of Oral and Maxillofacial Surgery, Saveetha Dental  College, Chennai, India    Y. Ashok  Department of Oral and Maxillofacial Surgery, Meenakshi Ammal  Dental College and Hospitals, Chennai, India    © The Association of Oral and Maxillofacial Surgeons of India 2021    It has always been a challenging job for the clinician to  manage temporomandibular disorder (TMD) as it is a conun-  drum wrapped in enigma.   Management of TMD is controversial because science  takes a back seat. We need scientific studies especially ran-  domised clinical trials to overcome this problem. Matching  the diagnosis to the treatment is still the most problematic  aspect of TMD practice. The solution lies in making an accu-  rate diagnosis to match an appropriate method of treatment.    The definitions for TMJ pain are not universally used. Three  currently accepted definitions of TMJ pain are:    1. Temporomandibular pain and dysfunction syndrome  (International Association for the Study of Pain: Merskey  and Bogduk [1])   (a) Aching in the muscles of mastication often associated  with restricted jaw movements and popping sounds   (a) Chronic or intermittent pain of TMJ and of its associ-  ated musculature    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1-15-1346-6_62    Over many years, functional disorders of the masticatory  system have been referred by many terms contributing to the  confusion regarding aetiologic mechanisms and manifesta-  tions in this area.   In 1934 James Costen [4], an otolaryngologist, described  a set of symptoms focused around the ear and temporoman-  dibular joint (TMJ) leading to the earliest nomenclature of  Costen syndrome. Costen believed these symptoms were due  to the backward displacement of condyle after overclosure of  the bite. Auriculotemporal nerve is found behind the tym-  panic bone which prevents nerve compression. Hence this  theory was rejected.   Schwartz [5] (1959) described myofascial pain dysfunc-  tion syndrome (MPDS) characterised by clicking, muscle  tenderness, pain in the TMJ region and restricted mouth  opening. Following this, much later the term TMJ distur-  bances became popular, and then, in 1959, Shore [6] intro-  duced the term TMJ dysfunction syndrome. Later Ramfjord  and Ash [7] brought forth the term functional TMJ distur-  bances. To establish a connect with the aetiology, terms such  as occluso-mandibular disturbance and myoarthropathy of  the TMJ [8] were introduced. When pain and associated  muscle involvement became the focus, terminologies such as  pain-dysfunction syndrome [9], myofascial pain-dysfunction  syndrome [10] and TM pain-dysfunction syndrome [11]  arose.   Currently it has been established that these terms attempt  to describe conditions with symptoms not always isolated to  the TMJ, and for the need of a broader, umbrella term to clas-  sify these conditions, some authors believe that the title cra-    Myofascial pain dysfunction syndrome (MPDS) is a well-  known term that is used in many other branches of medical  science [14-16]. But in the last few decades, this term has  been employed to describe orofacial chronic pain [17-19]  often abbreviated in the literature as MPDS.   Presently, myofascial pain can be defined as “a regional  myogenous pain condition characterised by local areas of  firm, hypersensitive bands of muscle tissue known as trigger  points” [20] alternatively called myofascial trigger point  pain. The presence of central excitatory effects is a defining  characteristic of this myalgic disorder. The presence of  referred pain is common, often resembling a tension-type  headache.    A number of mechanisms have been put forth to explain  myofascial pain, even though currently a holistic understand-  ing of aetiologies remains elusive (Fig. 62.1):    1. Continuous source of input leading to deep pain [21, 22]  2. Heightened emotional stress [21, 23]  3. Sleep disturbances [21, 24]    4. Local factors that govern muscle health, namely, habits,  posture and muscle strains   5. Systemic factors like nutritional deficiencies [21], poor  physical status, chronic fatigue and viral infections [21]    The patient’s main complaint is often directed towards the  site of referred pain and rarely the exact source of pain (the  trigger points). The clinician may accidentally direct treat-  ment towards the secondary sites of pain resulting in failure  to treat the actual cause of the pain, thereby leading to unsuc-  cessful treatment. History taking must specifically include  incidences of repetitive muscle trauma, improper postural  habits, presence of occlusal parafunction and mental and  emotional stress.   On clinical examination, the patient will display decreased  range and speed of mandibular movement which usually cor-  relates to the location and intensity of trigger point pain. The  pain is commonly described as a dull ache or pressure which  can be throbbing and severe. The masticatory muscles are  tender on palpation with identifiable trigger points on palpa-  tion [25].    Trigger points are described as firm knots within muscles  which are more tender on palpation than the surrounding  muscle tissue. The pain that is generated is usually within  and beyond the muscle and may occasionally elicit referred  pain to a distant site and even an autonomic response.   Temporary inactivation can be tried through a trigger  point anaesthetic injection, vapocoolant sprays, transcutane-  ous electrical nerve stimulation (TENS), etc. [26] which are  used by certain practitioners to temporarily inactivate trigger  points.   From a clinical standpoint, if the muscle is tender to pal-  pation and none of the other masticatory muscle disorders  better describe the patient’s condition, the suggested diagno-  sis is myofascial pain.    ¢ Questions concerning pain and restricted mandibular  movements and TMJ sounds  — Visual examination of the head and neck.  — Palpation of the head and neck—This includes palpa-  tion of the individual masticatory muscles for tender-  ness (Figs. 62.2a, b and 62.3).  — Listening to TMJ sounds and joint palpation (Fig. 62.4).   — Radiographs and other imaging techniques—An OPG  (Fig. 62.5) may be easily available in most clinical set-  ups. Dental cone beam CTs (Fig. 62.6) offer the advan-  tage of lowered radiation dose with reasonable hard  tissue detailing, articular surface erosions and joint  space dimensions. MRIs are useful for imaging soft  tissues such as the articular disc and joint ligaments  (Fig. 62.7a, b).    Pain in relation to the TM joint and masticatory muscles are  among the commonest complaints of patients with  TMD. MPDS is unique in that the contributing factors are  neurogenic, psychogenic and musculoskeletal in nature. This  greatly limits the role of conventional imaging modalities in  clinching the diagnosis of MPDS.   OPG and CT are useful in imaging bony articular surfaces  for erosions and changes in the joint spaces. MRI is excellent  for imaging the disc, capsule and TM joint ligaments.  However the usefulness of these imaging techniques appears  restricted to ruling out other contributing factors to the  patients’ pain such as internal derangement and osteo-  degenerative disorders. These features may often overlap  with myofascial pain, often adding to confusion in diagnosis.    A thorough clinical examination is the most reliable way to  arrive at a diagnosis of MPDS with imaging investigations  assisting in ruling out other causative factors. Figures 62.5,  62.6 and 62.7 demonstrate some of the conventional meth-  ods of imaging the TM joint and associated structures with  relevant findings.    It is mandatory to do psychological assessment or screening  of the patient for history of anxiety, depression and pain-  related disability.    Pain An unpleasant sensory and emotional experience  associated with actual or potential tissue damage, or  described in terms of such damage [27] (nternational  Association for the Study of Pain 1979).    Inflammatory Pain (ntra-articular tissue damage in associa-  tion with disc displacement results in local TMJ pain. In  addition, it can elicit reflex spasm of masticatory muscles  resulting in pain from regions other than TMJ.    Arthrogenous Pain The patient can point to the worst spot  with one finger in the TMJ region. The pain is relieved by  giving auriculotemporal nerve (ATN) block.    Myogenous Pain Not relieved by block and diffuse in nature  over the muscle.    Fig.62.6 CBCT shows erosions and craters in the head of the condyle and increased joint space    Fig.62.7 (a,b) MRI  showing disc displacement  without reduction in open and  closed positions    Bruxism is defined as an oral habit of involuntary rhyth-  mic non-functional gnashing or clenching of teeth outside  of masticatory movements of the mandible [28]—‘tooth  grinding neurosis”.   Associated with REM, commonly seen in patients with  high trait anxiety or increased depressive symptoms.  This sustained muscle contraction leads to non-serous  inflammatory reaction in masticatory muscles, subse-  quent fatigue and pain.    to highlight the problematic causative factors. These may  include central and peripheral causes as shown in Table 62.1.    e Deviation of mandibular midline to the affected side on  mouth opening before clicking   e Restricted laterotrusive jaw movements to the contralat-  eral side (Fig. 62.9a)   ¢ Unrestricted laterotrusive jaw movements to the affected  side (Fig. 62.9b, Table 62.2)   e Patient is instructed to open the mouth until jaw clicking  occurs indicating that the disc/condyle relationship is now  reduced into normal position.   ¢ No clicking sound is heard after placing the spacer  (Fig. 62.10a, b).    62.10 Principles of Management  62.10.1 Role of Evidence-Based Management  The varying manifestation of myofascial pain (MFP) can    range from single muscle involvement to complex cases  involving multiple sites of pain and numerous contributing    Fig. 62.8 (a) Attrition of  teeth from bruxism. (b)  Scalloping of tongue margins  (c) Linea alba    factors. The challenge in management consists of educating  patients about the lifestyle factors that contribute to MFP, the  persistence of which tends to result in treatment failure.  Studies by Fricton and Aronoff [29, 30] et al. indicate that  patients with MFP visit multiple practitioners in their quest  for relief and are often treated with multiple modalities in a  disorganised manner without experiencing improvement  other than on a temporary basis.    Patient must be encouraged to adopt therapeutic lifestyle  changes such as diet modification, exercise, proper sleep  habits, social support and coping mechanisms which may  contribute to more holistic and long-lasting positive  outcomes.    Patients exhibiting multiple and often overlapping risk fac-  tors are best approached via an interdisciplinary involvement  that uses a team of specialists to address the varied nuances    Fig.62.9 (a) Restricted laterotrusive jaw movements—contralateral side (b) Unrestricted laterotrusive jaw movements—affected side   3. Loose intra-articular bodies like arthroliths, intra-articular fracture  fragments of the articular surface [29]   4. Thickening of the soft tissue on the slope of articular eminence    of the problem in an organised manner. In both simple and  complex cases, the clinician needs to isolate the individual  problem area and arrive at a customised solution best suited  to the patient.    62.10.4 The Role of Occlusal Splint:  Termination of the Cycle of Habitual  Pain    Chronic pain is a learnt pattern that arises from repetition  and is generated by the CNS. This habitual pattern must be  arrested before attempting to treat MPDS. Treatment of  MPDS is dependent on breaking the repetitive pattern gener-  ated by the central nervous system. Nociceptive responses  are carried from peripheries into the central nervous system  (CNS) through myelinated (type A-delta) or unmyelinated  (type C) nerve fibres [31]. Dental malocclusion as a caus-  ative factor for MPDS has been found in literature since most  treatment modalities hint at occlusal alteration one way or  another. In a study by Laskin et al. [32], the authors remarked    that many aspects of MPDS are yet to be explored; many  have agreed that rapid improvement of symptoms is noticed  with splint therapy. Splint therapy is an effective method of  isolating occlusion as the causative factor as the interposition  of a splint can immediately and dramatically break the pain  pattern generated by the CNS. It is however necessary that  splint therapy be initiated by skilled practitioners.   Soft splints are constructed of polyvinyl worn at night. It  may act as a habit breaker.   The anterior bite plane or Lucia Jig is recommended for  short-term use and is to be worn at night. Stabilisation splints  help to disocclude the jaws, thereby restoring normal joint  space with prolonged wear. These are also used to correct  disc dislocations in internal derangement. The anterior repo-  sitioning splint allows the patient to close the mandible in a  forward direction; however, this has not yielded successful  results in many circumstances.   The gnathological splint was designed based on Roth’s  philosophy of correction of centric relation-centric occlusion  discrepancies. It is a permissive type of hard splint made of  heat cure clear acrylic fabricated using a semi-adjustable  articulator (SAM 3, AD2, PANADENT articulators). It is  usually worn full time in maxillary or mandibular arch. The  splint is designed on the concepts of gnathology to correct the  centric relation-centric occlusion (CR-CO) discrepancies,  which are a sequence of progressive disc derangements.   A few important factors to be considered prior to splint  fabrication include diagnosis and institution of therapy by  skilled clinicians, and alteration of occlusion results in    Fig.62.10 Diagnosis of  clicking sound in the TMJ. (a) a  Patient in closed mouth  position, with anterior disc  displacement (shown by TMJ  superimposition) and (b)  Condyle translating over the  displaced disc (TMJ  superimposition), to produce  clicking sound    changes in masticatory behaviour which in turn alters neuro-  muscular activity and learnt patterns of pain generation.  Regular follow-up is essential after splint usage. This helps  to identify any complications as a result of splint therapy  which might mandate stoppage of splint therapy altogether  [33, 34]. The specific type of splint and duration of treatment  must be carefully titrated for individual patients. Overuse of  the right splint can also result in worsening of the condition  by creating open bites, intrusion of teeth and loss of occlusal  contact and worsening of MPDS symptoms [35-37].    Wang et al. advocated elimination of premature contacts  using occlusal adjustment as one of the most crucial methods  for breaking the neuromuscular cycle in MPDS [38]. A thor-  ough occlusal analysis has consistently been an instrumental  diagnostic criterion to resolve MPDS symptoms.    Because of the prolonged and occasionally varied treatment  phases in the management of myofascial pain, the healthcare  provider must develop a long-term association with the  patient and direct the goals towards fostering a positive atti-  tude towards therapy and commitment to long-term change  [39, 40].    Muscle exercises are the most effective for muscle rehabilita-  tion. Active muscle stretching combined with passive exercises  diminishes the sensitivity of trigger points. Postural exercises  reduce trigger point reactivation, while strengthening exercises  serve to enhance circulation and suppleness of the muscles.  Determination of the muscular range of motion is the prelimi-  nary requirement prior to prescribing physiotherapy.   Postural exercises function to teach the patient to adopt a  more neutral and relaxed body position, thereby ameliorat-  ing fatigue from undue stress on a set of muscles. Inter-  incisal mouth opening is an effective indicator of muscle  range of motion, and limited mouth opening is indicative of  tender points in the masticatory muscles. Adverse postures  such as jaw thrust and forward head position must also be  discouraged.    1. Placement of the tip of the tongue on the roof of the  mouth with the teeth parted.   2. Instruction in proper posture for daily activities like sit-  ting, standing and lifting of objects.   3. Encourage sleeping on the side or back. This is effective  for patients who complain of muscle stiffness upon  awakening.   4. Incorporate a form of aerobic exercise into the daily rou-  tine to improve mood, circulation, strength and muscle  endurance [41].    There are various techniques for muscle stimulation.  Non-invasive methods of trigger point (TrPs) inactivation  include   e and ultrasound application which act as non-invasive  mechanisms of disruption.    Methods of chemical and mechanical alteration of TrPs are  achieved by:    Spray and stretch technique: Local muscle vapocoolant  spray application alongside passive stretching renders instant  pain relief [21, 42]. Failure of this technique has been attrib-  uted to:    (a) Inadequate achievement of full muscle dimension due to  bone or joint abnormalities, muscular contractures or the  patient’s inability to voluntarily relax    Pain reduction, improvement in range of motion, better exer-  cise tolerance and generalised enhancement of circulation in  muscles are some of the positive effects of trigger point  injections as documented by Cifala et al. [43] and Jaeger and  colleagues [44].   Trigger point injections act by physical disruption of the  trigger point from needle entry, and the pain relief may be    seen to last from the anaesthetic duration to several months.  Saline injections and “dry needling” have also been reported  with varying degrees of success. Dry needling, frequently  known as myofascial trigger point dry needling, is an alter-  native medicine practice comparable to acupuncture. It is  carried out by physical therapists where permissible by state  laws. The use of a combination of sub-anaesthetic doses of  local anaesthetic agents has also been found to be successful.  The results of a double-blind controlled trial by Simons et al.  [45] suggested 3% chloroprocaine and 5% procaine (without  vasoconstrictors) to be effective.   Corticosteroid in combination with a local anaesthetic  administered as a local intramuscular injection was first prac-  tised in the early 1950s. Though there haven’t been randomised  trials to prove the efficacy of the same, Gray and colleagues  suggested that locally delivered corticosteroids mitigate pain  and improve function in patients with MPDS [46].    These are areas of taut, inflamed muscle bands that elicit  pain on palpation. Pain of this origin is usually referred to  other sites in the local region. Figure 62.1 1a—e demonstrates  the various muscles of the head and neck and the related trig-  ger points elicited in MPDS.    Despite many MPDS cases being treated from an occlusion-  related standpoint, literature has shown dental occlusion or  partial and total edentulism to be weakly correlated as caus-  ative or maintenance factors of TMPDS [47, 48].   Therapies ranging from occlusal adjustments on natural  teeth to extensive prosthetic dental rehabilitation have been  reported. Other treatments include oral appliances and ortho-  dontics. Marbach [49] et al. demonstrated that missing teeth,  malocclusion and night-time bruxism in control group  patients did not correlate with facial pain and vice versa.    62.12 Intraoral Appliance Therapy (Refer to  suggested reading at the end of the  chapter)    Stabilisation appliances are well accepted, but the clinician  must ensure that they are not ill-fitting, bulky, etc., so it is  imperative to adjust them for patient comfort and better com-  pliance. Regular reviews and inspection for soft tissue ulcer-  ation, dental pain, oral malodours, speech impairment, caries,  tooth mobility and occlusal alterations must be carried out.  Splints: Box 62.2 enumerates the broad classification of  splints conventionally used in the management of MPDS.    Fig.62.11 Trigger points  (blue) in chewing muscles,  neck muscles and reflex pain  zone (yellow-orange): (a)  Masseter and temporalis. (b)  Lateral pterygoid. (c)  Posterior belly of digastric.  (d) Sternocleidomastoid (e)  Trapezius    Soft Bite Guard: Splint is constructed of polyvinyl worn  at night. It may act as a habit breaker and also serves to pro-  tect the occlusal surfaces of the teeth (Fig. 2).   The Anterior Bite Plane or Lucia Jig (Fig. €  short-term use to be worn at night.   Stabilisation Splint: It is a hard splint made of acrylic for  the restoration of occlusion (Fig. ). It minimises abnor-  mal muscle activity and restores neuromuscular balance.   Gnathological Splint: A specialised splint based on Roth’s  philosophy: To correct centric occlusal-centric relation dis-  crepancies (Fig. 62 ).   In the case of TMPDS, few controlled trials exist that indi-  cate daily use of NSAIDs offers little benefit when compared    Box 62.2 Splints Used in the Management of MPDS  (Refer to suggested reading at the end of the chapter)    to the well-known occurrence of side effects as reported by  Dionne et al. [50]. Singer and colleagues concluded that a  4-week trial of ibuprofen 1500 mg per day was no more  effective than a placebo [51]. Patients report short-term relief  with high doses of NSAIDs; however, long-term therapy  with NSAIDs is not encouraged.    62.12.1.2 Opioids and Narcotic Analgesics  With the use of opioid and narcotic analgesics comes the  problems of physical dependence, addiction and drug toler-  ance. There is a lack of controlled studies in literature to guide  the clinician regarding the same which restricts the use of  these drugs specifically to recalcitrant cases. Patient selection  is critical when instituting opioid therapy, and success of ther-  apy is usually measured by reports of reduction in pain inten-  sity, return to quality of life and achievement of a stable dose.  Oral opioids are, namely, sustained release morphine,  meperidine and butalbital in combination with aspirin and  caffeine. Transdermal fentanyl is effective in some cases.   Antidepressant drugs are frequently used in the management  of a number of pain conditions, including MPDS. Studies  indicate that these drugs behave independent to their role as  antidepressants since they are effective at low doses (on  average 23.6 mg for pain relief as opposed to a mean of  129 mg for depression) [52].   Amitriptyline and imipramine have been widely  researched for their antidepressant and pain control proper-  ties. Dosage is initiated at 10 mg during bedtime and, if  needed, is raised in 10 mg increments up to 30-40 mg.  Analgesic effects are noted to occur within a few days. Side  effects include sedation, constipation and dry mouth.  TMPDS case reports have shown anecdotal evidence sugges-  tive of agitation arising from selective serotonin reuptake  inhibitors. Citalopram, a Selective Serotonin Reuptake  Inhibitor (SSRI), had comparable effects to a placebo in the  treatment of fibromyalgia [53]. Earlier sources of literature  have also highlighted the efficacy of monoamine oxidase  inhibitor drugs (phenelzine, tranylcypromine) in the treat-  ment of orofacial pain conditions [54].   In the short term, diazepam and related muscle relaxants  bring about relief from painful muscle spasms but are effec-  tive only for a short-term basis.    Benzodiazepines are associated with development of tol-  erance when used for a long period of time among other side  effects. Varying degrees of relief have been reported with  relatively low (diazepam, 5 mg bid; clonazepam, 0.5 mg bid  or tid) doses, and usually an increase in dosage is not  mandated.    62.12.2 Supportive Therapy  62.12.2.1 Ultrasound and Electrogalvanic  Stimulation  Painful trigger points have been demonstrated to be managed  effectively with therapeutic modalities such as ultrasound  application and electrogalvanic stimulation (EG) [55].  Ultrasound causes localised muscle relaxation by producing  heat deep within the fibres corresponding to the trigger points  [56]. Low-voltage EG stimulation is used to stimulate mus-  cles in a phased and rhythmic manner. This results in muscle  relaxation and reduced muscle hyperactivity [57, 58]. These  techniques are generally considered conservative and are  extremely useful in mild to moderate cases of MPDS.   Box 62.3 outlines the prognosis and some of the impor-  tant pearls to be borne in mind by the clinician attempting to  treat MPDS.   e Accurate diagnosis—lIt is essential to isolate MPDS  from a host of conditions that may mimic symp-  toms such as internal derangement, migraines and  cluster headaches.   e Appropriate case selection—This necessitates the  correct identification of the disease phase and insti-  tution of appropriate treatment measures.    The management of MPDS can be summarised as follows  (Table 62.3). (Refer also to Chap. 63 - Internal Derangements  of the Temporomandibular Joint)    Newer management methods that have emerged in the recent  years for treatment of MPDS include botulinum toxin injec-  tions as well as cold and soft laser therapy.    Botulinum toxin injection enhances vascularity by augment-  ing the blood flow to the affected muscles and releases the  taut muscle fibres caused by abnormally contracting muscles  [59]. It has also been reported to increase endogenous endor-  phin secretion by way of needle insertion into trigger points  [60, 61]. However, studies reveal that 3-10% of patients  develop neutralising antibodies with long-term adverse  effects that include muscular atrophy [62].   The injection solution is prepared by dissolving 100 IU of  botulinum toxin into 1.0 mL of sterile saline solution (0.9%)  at room temperature to be done immediately before injec-  tion. An insulin syringe with a hypodermic needle may be  used for administering the injection. Small increments of this   ¢ Splints (bite appliances) are introduced  to prevent muscle overuse, including  bruxism    Cold laser therapy or low-level laser therapy (LLLT) has  been shown to play a substantial role in the treatment of gen-  eralised musculofascial disorders and facial pain relief [63-  66]. After a thorough clinical examination of the patient that  must reveal clearly the affected muscles, a treatment cycle is  formulated which usually consists of low-level laser applica-  tion like Ga-Al-As (Endolaser) of wavelength 780 mm for  4-6 weeks.   Theories put forth to explain pain reduction via low-level  laser therapy include hyperpolarisation of neuronal cell  membranes and resultant elevation of pain threshold along-  side an increase in the secretion of morphine-like substances  such as encephalin and endorphin which have an analgesic  and anti-inflammatory effect [11].   Since trigger points are known to be of inflammatory  nature [6], it can be concluded that laser application allevi-  ates oedema, inflammation and pain by inhibiting inflamma-  tory components such as prostaglandin (PGE2), prostacyclins,  histamine and kinin.    It would be appropriate to conclude that successful outcomes  and prognosis of MPDS are dependent on accurate diagno-  sis, appropriate case selection and above all an interdisciplin-  ary involvement that uses a team of specialists to address the  various nuances of the problems in an organised manner.    The clinician needs to isolate the individual problem  area and arrive at a customised solution best suited for the  patient.   The following salient points must be borne in mind by the  reader on completion of the chapter on MPDS as shown in  Box 62.4.    e Myofascial pain dysfunction syndrome is mainly a  pain disorder related to muscles and fasciae, dis-  tinct from TMJ disc interference disorders and tem-  poromandibular degenerative diseases.   e Myofascial pain can be defined as “A myogenous  pain condition characterised by Local areas of firm,  hypersensitive bands of muscle tissue known as  trigger points”.   e Bruxism and other parafunctional habits lead to  sustained muscle contraction and eventually non-  serous inflammatory reaction in masticatory mus-  cles, muscle fatigue and pain.   e Splint therapy as interposition can dramatically  break the pain pattern. “Lucia Jig” or anterior bite  plane recommended for short-term use helps to dis-  occlude the posterior teeth, thereby relieving mus-  cle fatigue and pain caused by sustained muscle  contraction due to clenching.   ¢ Non-invasive method of muscle treatment includes  inactivation massage, ice packs and Fluori-Methane  sprays.   ¢ Trigger point (TrP) injections with local anaes-  thetic, saline and steroids mitigate pain and improve  function.   e Anti-depressants like amitriptyline in small doses  (10 mg) at bedtime along with “Lucia Jig” for short-  term use give good pain control results.    A 29-year-old female patient complained of pain in the head  and jaw for the past 2 years and underwent medical treatment  for the same with little relief. On examination, muscles of  mastication were sore and there was difficulty in manipula-  tion of the jaw, and the patient showed a deep bite  (Fig. 62.16a). CBCT showed increased joint space and MRI  showed normal imaging. Having diagnosed with MPDS, the  patient was advised gnathological splint (Fig. 62.16b) for  full-time wear. The symptoms improved over 6-8 months.  Post splint therapy, the bite was considerably opened  (Fig. 62.16c), relieving pressure on the joint structures, and  the patient was forwarded for orthodontic settling.    A 48-year-old female patient complained of pain in the head  and neck for the past 1 year. All the symptoms started with  dental procedures which lasted long. On examination there  was severe muscle spasm with tenderness in muscles of mas-  tication and difficulty in opening mouth due to muscle spasm,  and deviation on mouth opening was also seen. Intraorally,  she had a deep anterior bite which was almost closed in rela-  tion to 11, 21, 31, 41 (Fig. 62.17a). CBCT and MRI showed  normal imaging, and hence she was advised a gnathological  splint (Fig. 62.17b) for her myofascial pain and to open the  bite. The symptoms improved over 3-5 months of full-time  wear, the bite was significantly opened and the patient was  referred for orthodontic settling of the bite.    A 21-year-old female patient who was a dental student  reported with clicking sounds and pain on both sides of the  lower jaw and severe teeth grinding at night for the past 6    Fig.62.16 (a) Anterior deep bite with spacing in the lower anteriors. (b) Gnathological splint in place. (c) Post splint therapy correction of deep    Fig.62.17 (a) Pretreatment occlusion showing anterior deep bite. (b) Gnathological splint in place. (c) Post splint therapy    Fig.62.18 (a) Palpation of  tender points on the  temporalis and masseter  muscles. (b) The Lucia Jig.  (c) Patient wearing the Lucia  Jig    months. The patient was clinically examined, severe tender-  ness was elicited on palpating the masseters and temporalis  bilaterally (Fig. 62.18a), and intraoral signs of enamel wear  from attrition were apparent. Imaging of the TMJ via MRI  showed a normal study. She was advised to wear a Lucia Jig  (Fig. 62.18b, c) for 3 months in order to disocclude the pos-  terior teeth. In addition, she was prescribed amitriptyline (10  mg) once a day at night which she took for the same period.  On follow-up after 3 months, she had complete relief from  the pain and reported complete cessation of the parafunc-  tional habit.    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Open Access This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.  org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropri-  ate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.    The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in    a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.   The term “internal derangement” has been used for more  than a century in surgical and orthopedic literature to describe  conditions that interfere with normal joint function [1, 2]. In  the knee, the term internal derangement is broadly used to  describe a torn, ruptured, or deranged meniscus of the knee,  a partial or complete cruciate rupture, with or without injury  to the capsular ligament of the knee, resulting in ongoing or  intermittent signs and symptoms such as pain, instability, or  abnormal mobility. Alterations in the disc, condyle-fossa  relationships in the temporomandibular joint (TMJ) were  suspected as early as 1887 by Sir Astley Cooper and pub-  lished by Annandale in the Lancet “on displacement of the  inter-articular cartilage of the lower jaw, and its treatment by  operation” [3]. The term internal derangement was adopted  and used to describe disturbances between the articulating  components of the TMJ, alluding to the damage to the inter-  nal structures and dysfunction of the joint associated with  changes in the position of the disc [4, 5].   In the TMJ literature, the term has evolved to be synony-  mous with disc displacement. In the 1970s and 1980s, TMJ  internal derangement was perceived as a mechanical prob-  lem and resulted in attempts to reposition or replace the disc.  In 1979, McCarty and Farrar stressed on the relevance of  disc displacement as a major disorder of the TMJ [5]. It was  believed that a displaced or abnormal disc was a progressive  problem that led to degenerative joint disease and as a result  importance was given to repositioning the displaced disc.  Conservative therapy was done by mandibular manipulations  and oral appliances, and surgical repositioning was per-    Electronic Supplementary Material The online version of this chap-  ter (https://doi.org/10.1007/978-98 1-15-1346-6_63) contains supple-  mentary material, which is available to authorized users.    G. Warburton (  Department of Oral and Maxillofacial Surgery, University of  Maryland School of Dentistry, Baltimore, MD, USA    © The Association of Oral and Maxillofacial Surgeons of India 2021    formed for patients who had persistent symptoms. A com-  monly performed surgical procedure was repositioning of  the disc, and if the disc was perforated or beyond repair, even  discectomy was performed. Various materials and tissues  were used for disc replacement (cartilage, dermis, muscle  fascia, fat, silastic, and Proplast-Teflon). However, the use of  Proplast-Teflon resulted in severe destruction of the articular  surfaces due to foreign body giant cell reactions [6-8].   Over the past few decades, there has been a conceptual  shift from internal derangement and disc displacement being  a primary diagnosis toward our current understanding that  disc displacement/internal derangement is an endpoint and a  manifestation of a process in which there is damage to artic-  ular tissues and biomechanical failure from a specific cause  that must be identified if treatment is to be successful.   Clinical and basic science research has led us to the con-  clusion that internal derangement represents a variety of  stages of biomechanical failure of the joint tissues, resulting  from different causes.Wilkes staging system (Table 63.1)  categorizes the extent of joint damage in internal derange-  ment without being specific for the underlying cause that is  responsible for the failure of the joint tissues. With this limi-  tation in mind, Wilkes classification [9] is still useful today  in communicating severity and guiding treatment.   The realization in the 1990s that arthroplasty with disc  repositioning or discectomy often leads to degenerative joint  disease and fibrosis, coupled with the fact that the disc reposi-  tioning was not reliably maintained, caused a major change in  surgical management. Arthroscopic surgery of the TMJ was  shown to be an effective alternative to arthroplasty. Arthroscopy  was a reliable procedure to reduce the pain and to improve the  maximal incisal opening without causing a change in position  of the disc [10-15]. The role of disc displacement and disc  position in symptomatic patients has been further questioned  due to the fact that MRI studies have documented disc dis-  placement in 32-38% of asymptomatic patients and volun-  teers [16, 17]. We now know that the abnormally positioned  disc is not the primary cause on pain and dysfunction for many    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1-15-1346-6_63    1362  Table 63.1 Wilkes classification  Stage I Painless clicking  Early Anterior disc displacement with reduction  Stage II Clicking with intermittent pain and locking  Early Anterior disc displacement with reduction  intermediate  Stage III Pain, joint tenderness, frequent and prolonged  Intermediate locking, restricted motion,  No degenerative changes  Anterior disc displacement with or without  reduction  Stage IV Chronic pain, restricted motion, no clicking,  Intermediate- degenerative bony changes  late Adhesions  Anterior disc displacement without reduction  Stage V Variable pain, painful function, reduced function,  Late crepitus, advanced    patients as the majority of patients with displaced discs are  asymptomatic through the process of adaptation.   Arthrocentesis was subsequently introduced as another  effective yet minimally invasive means of treating patients  with symptomatic internal derangement [18-22].  Arthroscopy and arthrocentesis allowed sampling synovial  fluid and has been of tremendous value in our understanding  of the biochemical mediators and cytokines responsible for  inflammation, cartilage degeneration, and destruction of  joint tissue leading to internal derangement [23-26].    Diagnostic criteria for temporomandibular disorders  (TMD) for research and clinical purposes were recently  updated in 2014 [27] and include internal derangement  or disc displacement which is presented as:    Normal disc position, displacement with reduction, and  displacement without reduction are depicted in Fig. 63.1.    Internal derangement of the TMJ is a relatively common  problem. Farrar estimated that up to 25% of the population  has TMJ internal derangement [28]. Epidemiologic studies  have shown that TMJ clicking is detectable in up to 31% of    the population, and crepitus is detectable in up to 40% of the  population on auscultation, with a higher prevalence among  women.   MRI studies have documented disc displacement in  32-38% of asymptomatic patients and volunteers [15, 16].  The mean age for TMJ disorders is 34 with 90% of patients  falling within 15-45 years of age range. Agerberg et al.  studied 637 people aged 18-65 and found an incidence of  21% clicking in men and 28% in women, while crepitus  was noted in 26% of men and 40% of women [29]. Disc  displacement occurs most commonly in the anterior or  anteromedial direction, which is the most common direc-  tion of displacement followed by lateral and rarely poste-  rior displacement accounting for only 0.7% of  displacements [30].    Internal derangement is an endpoint and a manifestation of a  process in which there is damage to articular tissues and bio-  mechanical failure from a specific cause that must be identi-  fied if treatment is to be successful. The broad etiologic  categories resulting in internal derangement are:   e An abnormal joint subjected to normal load (rheumatoid,  SLE or psoriatic arthritis, osteochondroma,  chondromatosis)    The majority of patients fall into the normal joint sub-  jected to overload etiologic category and in particular due to  parafunctional habits of clenching or bruxism during the day  or at night.   Historically occlusion has been considered a primary eti-  ologic factor, but this has now been refuted in current  evidence-based literature [31, 32].    The TMJ is a hinging and sliding synovial joint (ginglymo-  arthrodial joint) and forms the articulation between the man-  dibular condyle and the temporal bone. The articular surfaces    Fig. 63.1 Normal and displaced disc positions, with and without reduction (modified with the permission of Dr. Robert Talley)    are covered with fibrocartilage, while most other synovial  joints are composed of hyaline cartilage. Fibrocartilage is  composed of fibrochondrocytes, fibroblast-like cells, type I  collagen, and proteoglycans. Fibrocartilage is less suscepti-  ble to degeneration and also has a greater repair capacity  compared to hyaline cartilage [33]. The articular disc or  meniscus that is interposed between the mandibular condyle  and articular eminence of the temporal bone is also a fibro-  cartilaginous structure in the shape of a biconcave elliptical  disc. It has a thicker posterior and anterior band with a thin-  ner intermediate zone in between (Fig. 63.2). From a lateral  viewpoint in the closed mouth position when the condyle is  seated in the glenoid fossa, the posterior band is normally  positioned at the 12 o’clock position from a point in the cen-    ter of the condyle. As the condyle rotates and translates for-  ward beneath the disc during mouth opening, the disc comes  to lie above the condyle (this has been termed “roofing”).  The disc itself is an avascular structure and that has no inner-  vation. The metabolic and nutritional requirements of the  avascular disc are provided by the surrounding synovial fluid  through a process known as weeping lubrication (whereby a  small amount of synovial fluid is forced into and out of the  disc during the compressive forces generated by joint func-  tion and loading of the disc). The disc is anchored to the  medial and lateral poles of the condyle by the collateral (dis-  cal) ligaments (Fig. 63.3).   Figure 63.4 shows the attachments of the disc in a sagittal  view. The posterior attachment of the disc is the retrodiscal    Fig. 63.2 Articular disc or meniscus (normal position) (Also see normal disc position in open mouth and closed position in Fig. 63.1)    Fig. 63.3 Coronal view of the medial and lateral collateral (discal)  ligaments    Fig. 63.4 Attachments of the disc in a sagittal view (modified with the  permission of Dr. Robert Talley)    tissue. The retrodiscal tissue is a bilaminar structure with a  superior lamina, inferior lamina, and intervening loose con-  nective tissue that is very vascular and well-innervated. The  retrodiscal attachment connects the disc to the tympanic  plate of the temporal bone by the superior lamina, which is  composed of connective tissue and elastic fibers. These elas-  tic fibers condense to form a prominence recognized  arthroscopically as the posterior oblique protuberance/band.  The inferior lamina is composed of collagen fibers and  inserts into the condylar neck. The disc and retrodiscal tissue  together divide the TMJ into upper and lower joint spaces  which are filled with synovial fluid. The anterior attachment  of the disc is to the temporal bone, the anterior condylar  neck, and the upper head of the lateral pterygoid muscle,  while the medial and lateral attachments are to the capsular  ligaments as well as the collateral ligaments. All the joint  surfaces are covered with synovial lining except the disc  itself, glenoid fossa, articular eminence, and condylar head.   It is the collateral (discal) ligaments along with the supe-  rior and inferior lamina of the retrodiscal tissue that are dis-  rupted and elongated when the disc is displaced anteriorly in  internal derangement.   The glenoid fossa of the temporal bone lies immediately  beneath the middle cranial fossa (Fig. 63.5a, b). From both  arthroscopic and open surgical standpoints, one must recog-  nize that the bony roof of the fossa is extremely thin. An  autopsy study revealed that the glenoid fossa was only 0.2—  1.5 mm thick in normal joints and 0.5—2.0 mm thick in joints  with disc displacement [34]. Care must be taken not to per-  forate the thin roof of the fossa during arthroscopic and open  TMJ surgical procedures.   The TMJ is innervated by the trigeminal nerve, predomi-  nantly through the auriculotemporal branch of the mandibu-  lar division which passes behind the condylar neck and  penetrates the capsule to enter the joint. However, some  innervation also comes from the deep temporal and masse-  teric branches.    Fig.63.5 (a) Sagittal section through TMJ and glenoid fossa. (b) Cadaveric specimen viewed from the middle cranial fossa (brain removed) with  an arthroscope in the left TMJ. Both demonstrate the thin roof of the glenoid fossa    The most common presenting complaints in patients  with TMJ internal derangement include:    The loss of function may be due to limited mouth opening  (closed lock in anterior disc displacement without reduc-  tion), a mechanically obstructive click, or dietary compro-  mise secondary to pain.    A good clinical history is essential for accurate diagnosis of  any TMJ disorder including internal derangement. Questions  including onset and evolution of the problem may reveal a  classical story of a clicking or “popping” joint, indicating a  disc displacement with reduction, or a story in which a  patient with a history of a clicking joint notices that the click  suddenly disappears and at the same time develops limited  mouth opening and pain indicative of progression to disc dis-  placement without reduction. Questions regarding initiating  factors are helpful in identifying the underlying etiology  (trauma or parafunction). Patient reports of pain increasing  with stress or pain present on waking from sleep are strongly  suggestive of parafunctional habits.   The answers to these pain questions may suggest pain  originating from the joint when the pain is localized over the  preauricular area, compared to muscular pain when it is more    Other questions should include details of prior treat-  ment attempts and specific questions regarding pain:    widespread, a critical differentiation in determining appro-  priate management. Problems with other joints such as pain  or laxity may suggest systemic arthritis or even conditions  such as Ehlers-Danlos syndrome.    Should include examination of the muscles of mastication,  TMJ, range of mandibular motion, and intraoral examination  to evaluate occlusion and signs of parafunction (buccal  mucosal ridging at the level of the occlusal plane, scalloping  of the lateral border of the tongue, tooth wear, and fractured  teeth or restorations).   When examining each pair of muscles, one should evalu-  ate for tenderness, trigger points, muscle mass, and tone. If  the patient reports pain on palpation (indicating myalgia), it  is helpful to determine if the pain is localized to the point of  palpation (local myalgia), spreading beyond the point of pal-  pation but within the muscle boundary (myofascial pain), or  radiates outside the muscle boundary (myofascial pain with  referral).    Fig. 63.7 Anterior disc  displacement and retrodiscitis  (as seen in the inset  arthroscopic image) with a  positive direct pressure  loading test of the right   TMJ = biting on tongue  blades between left canines  loads the right TMJ, and pain  is reported in the right TMJ    When examining the joint, one should evaluate for tender-  ness, swelling, range of motion (hinge and translation), sym-  metry of motion or deviations, subluxation/dislocation,  clicks, and crepitation. Joint noises may be audible or pal-  pable, but some may only be detected by auscultation.  Timing of any opening click provides clinical information on  the extent of disc displacement before reduction. A very  early click on condylar translation suggests minimal anterior  disc displacement before reduction, while a late click sug-  gests greater anterior displacement of the disc. If the disc is    anteriorly displaced, there may be significant retrodiscitis  due to the condyle functioning on the retrodiscal tissue rather  than the disc itself (Fig. 63.7). If the patient is asked to bite  on two wooden tongue blades between the canine teeth and  they report pain localized to the contralateral TMJ that is  now being loaded, this is pathognomonic for retrodiscitis  and is known as a positive direct pressure loading test.  Crepitations often indicate perforation, usually in the retro-  discal tissues, and may occur due to long-term function on  the retrodiscal tissue or trauma.    While plain radiographs and CT scans are useful for evaluat-  ing bony changes, MRI scans are best suited for evaluating  disc position and displacement and have a diagnostic accu-  racy of at least 90% [35]. MRI should be ordered with both  T1 and T2 images in the open and closed mouth positions    (Fig. 6 ); often additional imaging sequences are help-  ful such as fat suppressed or STIR sequences which help to  show edema in tissues that contain fat. This can be helpful in  evaluating edema in the cancellous bone of the condylar  head. Using MRI, one can assess the bone of the condyle,  fossa, and eminence (looking for sclerosis, erosions, flatten-  ing, osteophytes, and breaks in cortical continuity), the disc    Fig.63.8 (a—c) MRI scan—T1 and T2 images in closed and open mouth positions. (a) Normal disc position. (b) Anterior disc displacement with    reduction. (c) Anterior disc displacement without reduction and superior joint space effusion    (ooking at its position, density, shape, size, and continuity in  cases of perforation), effusions which are easily seen on T2  sequences, and finally for collapse of the joint space. The  sagittal closed and open mouth images determine if the disc  is displaced and whether or not it reduces on opening.    Is helpful in the diagnosis of primary inflammatory arthritis  (Table 63.2). Rheumatoid factors (RFs) occur in 60-80% of  patients with rheumatoid arthritis (RA) [36]. While they are  sensitive, their diagnostic utility is limited by their relatively  poor specificity, since they are also found in 5-10% of  healthy individuals, 20-30% of people with SLE, virtually  all patients with mixed cryoglobulinemia (usually caused by  hepatitis C virus infections), and those with many other  inflammatory conditions. Higher titers of RFs (at least three  times the upper limit of normal) have somewhat greater  specificity for RA. The prevalence of RF positivity in healthy  individuals rises with age. More recently, other antibody  markers have been utilized. Anti-cyclic citrullinated peptide  (anti-CCP) antibodies have a similar sensitivity to RF for RA  but have a much higher specificity (95-98%). Anti-CCP anti-  bodies are also present early in the disease, and their pres-  ence often correlates with more severe forms of RA, making  them better prognostic indicators [37]. HLA-B27 is associ-  ated with seronegative spondyloarthropathies, psoriatic and  reactive arthritis [38].    Serology ¢ Rheumatoid factor > Rheumatoid arthritis  ¢ HLA B-27 = Reactive arthritis, ankylosing spondylitis,  juvenile reactive arthritis  e ANA > Autoimmune D/O (e.g. rheumatoid arthritis,  systemic lupus erythematosus)  ¢ Anti-citrullinated protein antibody ACCP — Aid in dx of  RA and its prognosis    In complex cases where history and examination fail to  clearly confirm pain originating from the joint itself, or in  cases that have undergone previous surgeries on the TMJ, or  in chronic pain patients, an auriculotemporal nerve block  and injection of local anesthetic into the superior joint space  is very helpful and can demonstrate the amount of pain origi-  nating from the joint. The author uses 3% mepivacaine  injected using a dental syringe (Fig. 63.9a—c). With the  patient in occlusion, the needle is inserted and advanced to  contact the posterior condylar neck where half the carpule is  injected as an auriculotemporal nerve block. The patient then  opens their mouth, and the needle is advanced superiorly to  contact the posterior slope of the articular eminence, and the  remaining anesthetic is deposited into the superior joint  space. The patients pain score before is compared to the pain  score 10-15 min after injection. Any portion of pain that has  resolved is most likely originating from the joint. This is  helpful in determining if surgery is indicated and also in pro-  viding realistic postoperative pain expectations for the surgi-  cal patient.    Treatment for internal derangement can be divided  into nonsurgical and surgical options, but the general  treatment goals are the same:    Clinical research [39-41] into the natural progression of * About 25-33% of patients do not improve.    TMJ internal derangement has shown: e Older patients and those with MRI evidence of more    ¢ Onan average, about | year is required for the resolution  of symptoms , but this time is variable.   Patient education is of great value. A simple explanation  of the mechanics causing a clicking joint with internal  derangement with the information that around 30% of the  population have internal derangement can be very reassuring  and put a patient’s mind at ease. Furthermore, educating the  patient in habit awareness to avoid daytime clenching is a  key element in the long-term success of any nonsurgical or  surgical treatment (Table 63.3).   Orthotic devices or occlusal appliances may help to  reduce nighttime parafunctional habits. However, our under-  standing of orthotic devices has changed significantly over  time. In the late 1930s and 1940s, temporomandibular joint  disorders (TMD) used to be seen as problems related to  occlusal or skeletal disharmony. Costen was an otolaryngol-    ogist who in 1934 first suggested the link between occlusion,  TMJ disorders, and ear symptoms based on his observations  in 11 patients [42]. This evolved into orthotics and occlusal  therapies being used for the treatment of TMJ disorders in  the 1940s and 1950s. However, a significant paradigm shift  has occurred as the classic dental and skeletal etiologic theo-  ries have been challenged and refuted by studies conducted  around the world, and a biopsychosocial medical model of  orthopedics, pain phenomenology, and behavioral factors  has gradually replaced them. As a result, the conceptual basis  for occlusal appliances/orthotic use has significantly changed  over the years. Occlusal appliances/orthotics were initially  conceived and used based on these old dental and skeletal  etiologies and were thought to produce occlusal disengage-  ment, relax jaw musculature, restore vertical dimension of  occlusion, unload the joint(s), or reposition the condyle and  or disc. Even today, these are often described as deprogram-  mers or jaw-repositioning devices that can establish ideal  craniomandibular relationships wile relieving pain and  restoring function. Until the 1960s, there were no well-  controlled, well-designed, systematic studies evaluating the  treatment of TMD. Instead, there were a number of anec-  dotal reports claiming success with various mechano-dental  treatments, including various designs of oral appliance or  orthotic [43, 44]. As the evidence-based literature has  evolved, these reports have been refuted. Lundh [45] divided  patients with symptomatic TMJ disc displacement into two  treatment groups: one group with no treatment and one group  with an occlusal appliance/orthotic and compared outcomes.  After 12 months, pain had resolved in around 33% of patients  in both groups. 40% of patients reported increased pain in  the occlusal appliance/orthotic group compared to 16% in  the no treatment group. Truelove [46] evaluated 200 patients  with anterior disc displacement with reduction, arthralgia,  and myalgia who were randomly assigned into three treat-  ment groups: group | had basic nonsurgical treatment (edu-  cation, self-care, hot/cold packs, and passive stretching),  group 2 had hard flat plane occlusal appliance/orthotic, and  group 3 had soft splint. Outcomes were evaluated after 3 and  12 months, and there were no significant differences in suc-  cess among the three groups. Greene [47] and Laskin [48]  studied the placebo effect using mock/sham occlusal appli-  ances and sham occlusal adjustments. They found that non-  occluding appliances/orthotics helped over 40% of patients  and mock/sham occlusal adjustments helped almost two-  thirds of patients. Furthermore, the use of occlusal appli-  ances/orthotics may increase the parafunctional habit in  some resulting in a patient complaining of increased pain  and/or stiffness after use. In addition, partial coverage  devices may result in occlusal changes if used for more than  a few months due to eruption of teeth. Therefore, our percep-  tion of occlusal appliances/orthotics must take into consider-  ation the current evidence-based literature.    In review of evidence-based literature on occlusal  appliance/orthotics [45—47, 49, 50], we can conclude:    e Symptoms of myalgia and arthralgia may be  decreased by occlusal appliances.   e Wear on the dentition caused by parafunctional  habits may be reduced.   e Over time, many patients show improvement in  signs and symptoms.   e There is no appreciable significant difference  between the nontreatment and treatment group.   e Palliative care (NSAIDs, education, diet modifica-  tion, exercises) seem to be as effective as more  expensive appliance therapy.    In Klasser’s review [50] of occlusal appliances/orthotics,  he concludes that rather than trying to establish new horizon-  tal or vertical jaw relationships, occlusal appliance/orthotics  today should be viewed as “oromandibular crutches,” which  are analogous to back braces or ankle support orthotics  because they support the joint and provide symptomatic  relief while the joints are recovering. Table 63.4 outlines  Klasser’s conclusions on occlusal appliance use and  limitations.   Most often, painful internal derangement causes a reac-  tive muscle response. This muscle response and myalgia can  be treated by soft diet, heat, and massage to the affected  muscles, limiting the range of motion to within the pain-free  range, NSAIDs, muscle relaxants, physical therapy, and even  botulinum toxin injections (e.g., Botox).   ¢ Protect teeth/restorations from ¢ Unload the disc by pivoting  fracture due to bruxism/clenching the mandible on the molars   ¢ Reduce headaches related to bruxism/clenching  bruxism/clenching ¢ Relieve headaches that are    ¢ Reduce internal derangement  symptoms related to bruxism/  clenching upon awakening    The vast majority (approximately 90%) of TMD patients will  experience symptom resolution either spontaneously or with  nonsurgical treatment [51]. This resolution of symptoms  occurs due to the underlying adaptive capacity of the  TMJ. Given that internal derangement is a common MRI  finding in 32-38% of asymptomatic patients and volunteers  [16, 17] and that arthrocentesis or arthroscopy without disc  repositioning is so successful, it is evident that the TMJ has  the ability to adapt to the disc displacement in the vast major-  ity of patients. Those patients with internal derangement and  disc displacement that do not adapt are potential surgical can-  didates. It is the authors’ preference to follow a surgical pyra-  mid algorithm with most patients beginning with arthroscopy  unless there are specific indications otherwise (e.g., ankylo-  sis). Since no single surgical procedure carries a 100% suc-  cess rate, patients who fail one level (phase 1) on the algorithm  progress further up the pyramid to a second (phase 2) surgical  procedure with phase 2 procedure being determined by the  arthroscopic findings of phase 1.    This minimally invasive procedure was introduced after the  success of simple arthroscopy was recognized. Arthrocentesis  in the TMJ was first described in 1987 by Murakami using a  single needle pumping technique to create a hydraulic dis-  tention of the upper joint space [52]. Nitzan and Dolwick  [18] subsequently modified the technique and used two  needles. It provides lysis and lavage of the upper joint space    Fig. 63.11 Arthrocentesis—using the Holmlund-Hellsing markings  measured along the trago-canthal line (10 mm forward from mid-tragus  and 2 mm down correspond to the glenoid fossa entry site)    using an inflow needle, an outflow needle, and at least 300 ml  Lactated Ringer’s irrigation solution (Fig. 63.11). The lysis  is accomplished by the hydraulic distention of the superior  joint space, while the lavage removes inflammatory media-  tors, cytokines, and debris (Fig. 63.12). It is through the lysis  and lavage that the adhesions are separated and the inflam-  matory mediators and debris are removed. Several authors  have since reported success rates of arthrocentesis in the  management of internal derangement ranging from 70 to  95% [18-22].    Minimally invasive arthroscopic surgery for the TMJ was  first performed by Ohnishi in 1974 and subsequently devel-  oped in the 1980s by several surgeons (Murakami, Holmlund,  McCain, Saunders, and others). TMJ arthroscopy has proven  to be an effective and reliable alternative to open joint sur-  gery for many patients, resulting in reduced pain and  improved maximum incisal opening [10-15] with success  rates as high as 91% [12]. TMJ arthroscopy can be as simple  as a visually assisted lysis and lavage or as complex as per-  forming disc repositioning and fixation. The author uses  McCain’s terminology to categorize different levels of  arthroscopy according to complexity and number of portals  of entry (Table 63.5).   The authors preferred surgical sequence for performing a  level 1 arthroscopy as outlined in Table 63.6 (Video 63.1). All  arthroscopy should begin with an examination under anesthe-    Level I Arthroscopy  ¢ Single puncture & outflow needle  ¢ Lysis& lavage  ¢ Diagnostic sweep  ¢ Needle/scope adhesiolysis  Level II Arthroscopy  ¢ Double puncture & outflow needle  ¢ Level I  ¢ Instrumentation port (laser, coblation, grasper, probe etc.)  Level III Arthroscopy  ¢ Triple puncture & outflow needle  ¢ Level II  ¢ Discopexy(suture/screw)    sia of the TMJ. The EUA allows the surgeon to anticipate what  might be encountered upon entering the joint arthroscopically.  The range of condylar translation is noted, and whether trans-  lation is onto the peak of the articular eminence stops short of  the peak or beyond the peak of the eminence as in subluxation  and even dislocation. In addition, if there is very limited trans-  lation or just hinging, the surgeon might expect a tight joint  space filled with adhesions and a fibrous arthrosis potentially  making the arthroscopic puncture, joint access, and visualiza-  tion difficult. Joint noises (clicking and crepitation) should be  noted, and bone-on-bone crepitations are indicative of a perfo-  ration in the retrodiscal tissue.    In addition to the lysis and lavage as in arthrocentesis  (Table 63.6), a level | arthroscopy provides a diagnosis and  identifies intra-articular pathology (Fig. 63.13a—f). A sys-  tematic diagnostic sweep through the entire superior joint  space is performed to obtain the diagnostic information.  Level | arthroscopy can be accomplished using a standard  operative arthroscope (usually 1.9-2.7 mm) or the more  recently available disposable scopes (1.2 mm). While the  image quality from a disposable scope is currently not as  good as the traditional operative arthroscopes, it does allow  for adequate visualization and a diagnosis.   Level 2 arthroscopy includes a second puncture with an  operative cannula and allows for additional procedures such  as disc mobilization, biopsy, laser ablation, or coblation to be  performed. Video 63.2 shows the second cannula being  inserted, disc mobilization with a probe, and laser ablation of  hyperplastic polypoid synovitis.   Level 3 arthroscopy with multiple cannulas allows for more  advanced techniques and disc repositioning with fixation, using  sutures, wires, pins, or screws. The author uses a suture tech-    nique to anchor the repositioned disc as shown in the  Video 63.3. Figure 63.14a, b shows the suture placed through  the posterior band of the disc anchoring it into the reduced  position. The arthroscopic suture video clearly shows how  tightening the suture reduces the anteriorly displaced disc.   Several surgeons have described and published tech-  niques to reposition and fixate the displaced disc [53-59].  Success in the early reports of arthroscopic disc reposition-  ing was not high. Yang reported better success rates with par-  tial and later complete anterior release of the disc from its  anterior attachment and suggested that relapse rates without  complete anterior release are high [55]. While more recent  success rates of disc repositioning as high as 95.3% [60]  have been reported, many of these studies have relatively  short-term follow-up and/or no MRI confirmation of long-  term stability of the disc repositioning.   It is the authors’ opinion that level 3 arthroscopy should be  performed primarily for functional reasons, e.g., a mechani-  cally obstructive click, closed lock, or subluxation. In  McCain’s publication on arthroscopic discopexy [59], the    Fig.63.13 (af) Arthroscopic pathology. (a) Retrodiscitis (b) Adhesions (c) Small disc tear/perforation (d) Large perforation with condyle visible    Fig. 63.14 (a, b)  Arthroscopic suture  discopexy—suture placed  through the posterior band of  the disc anchoring it into the  correct reduced position    success rate in 42 joints was 86.7% in Wilkes II and III but  only 25% in Wilkes IV and V which emphasizes that case  selection is a key element to success. For disc repositioning to  be indicated and have good outcomes, the disc must be sal-  vageable, and there must be sufficient posterior joint space  height in which to reposition the disc. In other words, the disc  must be intact, and MRI evaluation must confirm normal disc  morphology with adequate posterior joint space height in  which to reposition the disc. If the joint space has collapsed as  is often the case in longer-standing/chronic disc displace-  ment, the load placed during function on the repositioned disc  will be excessive, and the fixation will likely fail, leading to  displacement again. Postoperatively, all patients will notice a  malocclusion with slight mandibular deviation to the contra-  lateral side. However, the majority of these malocclusions  will resolve within 3 weeks. Additional factors to success are  the postoperative physical therapy and dietary instructions.  The author instructs his patients to perform “limited range of  motion” exercises for the first 3 weeks to minimize the risk of  the fixation failing or tearing through the disc. This is achieved  by instructing the patient to keep the tongue on the roof of the  mouth while performing opening exercises. The diet should  be soft with minimal chewing and as for all surgical cases and  any parafunctional habits should be well controlled. After 3  weeks, the patients gradually increase their mouth opening  with daily stretching exercises. Associated myalgias may  improve once the joint pain and function improve following  arthroscopy, but often concomitant nonsurgical treatment of  the muscle disorder is also required.   At the end of the arthroscopic procedure, the surgeon has  the option of injecting medications including steroid, hyal-  uronic acid (HA), and platelet-rich plasma (PRP).    63.6.4.1 Viscosupplementation with Hyaluronic  Acid  Hyaluronic acid is a glycosaminoglycan polysaccharide nat-  urally found in synovial fluid. It is produced by the chondro-  cytes and synoviocytes and plays an important role in joint  function and nutrition. HA is the main contributor to the vis-  cosity of synovial fluid and provides protection under joint  loading. Inflammatory disorders of the TMJ including inter-  nal derangement are associated with reduced quantity and  quality of HA through a process of destruction and also the  production of HA that is lower in molecular weight [61, 62].  The short half-life of injected HA makes it unlikely that its  effectiveness is due to restoration of the viscosity of the  synovial fluid [63]. It is suggested that supplementation with  injectable HA could have anti-inflammatory and analgesic  effects [64]. Altman suggested that injection of HA could  lead to repair of the articular cartilage/fibrocartilage and nor-  malize the synthesis of endogenous HA [65].  Viscosupplementation has been described in orthopedic  literature for many years, but there are discrepancies in the  evidence to support the widespread use of intra-articular  hyaluronic acid to treat knee osteoarthritis. However, several  recent studies have shown hyaluronic acid to be a viable  treatment option showing longer-term improvement in both  knee pain and function. Unfortunately, similar uncertainty  exists regarding the effectiveness of viscosupplementation  using hyaluronic acid in the TMJ [66-68]. Beyond visco-  supplementation, there are some additional benefits to using  HA in TMJ arthroscopy. If the surgeon is having difficulty  maneuvering the scope because of a tight joint space, the  lubricant properties of HA may be helpful in minimizing iat-  rogenic damage to the joint surfaces and disc. It is also help-    ful at the end of the procedure in reducing the bleeding from  a hyperemic joint.   Is a concentration of platelets and growth factors taken  from autologous blood. It has reported beneficial effects  in joint degeneration and tendinopathy [69-72], and there  is both literature supporting its effectiveness in TMJ  arthroscopy [73-75] and conflicting literature reporting  no benefit [76, 77]. Therefore, the use of PRP after TMJ  arthroscopy remains controversial, and further studies are  needed [78].    63.6.4.3 Open Joint Surgery and Arthroplasty  The effectiveness of minimally invasive procedures such as  arthrocentesis and arthroscopy has significantly reduced the  frequency and volume of open joint surgery (disc reposition-  ing or discectomy). However, currently there are very few  surgeons trained in the advanced technique of arthroscopic  discopexy, and so for patients who fail level | or 2 arthros-  copy and require disc repositioning surgery, open joint sur-  gery with disc repositioning may be the next surgical step in  moving up the surgical pyramid. Annandale first published  “On displacement of the inter-articular cartilage of the lower  jaw and its treatment by operation” in 1887 [3], but it wasn’t  until later that surgery for internal derangement became pop-  ular. Surgical interest in disc displacement began with reports  from McCarty and Farrar [5] claiming disc repositioning  success rates of 94% using a wedge resection and suture pli-  cation technique. However, other surgeons were not as suc-  cessful, and the long-term stability of suture plication  techniques was low, leading to multiple variations of open  surgical disc repositioning and methods of fixation [79-82].  In 2001, Wolford reported a more rigid fixation technique  using a Mitek mini-bone anchor to fixate the repositioned  disc [83]. In this technique, the anterior and lateral disc  attachments are released allowing passive disc repositioning.  The disc is separated at its junction with the retrodiscal tis-  sue, and Mitek anchor is inserted into a 2-mm hole drilled  into the posterior condyle 8—10mm below articulating sur-  face. Two O-Ethibond braided sutures are inserted through  the posterior band of the disc in a mattress suture fashion  fixing the disc to the Mitek anchor (Fig. 63.15a—c). Although  radiographs at the longest follow-up showed no condylar  resorption and stable position of the metal anchor, the stabil-  ity of the disc repositioning was not evaluated by  MRI. Despite this, Wolford reported that there was a statisti-  cally significant reduction in TMJ pain, facial pain, head-  aches, TMJ noises, and disability and improvement in jaw  function and diet.    Alternative fixation and anchoring devices are avail-  able on the market today. He et al. use a self-drilling mini-  screw and have modified the technique to include a  complete anterior release and overcorrection of the disc  position for better stability of the repositioning. They  report stable short-term (mean 10 months) disc position  on MRI in 98.6% of patients [84]. Zhou et al. evaluated  the same technique in 149 joints and the long-term stabil-  ity of the repositioned disc on MRI at a mean longest  follow-up of 23.4 months (range 12-84 months) and  reported that 95.3% of discs were still in position, whereas  4.7% had relapsed anteriorly [85]. They also reported new  condylar bone formation in 74.5% of joints and even  greater in young patients (under the age of 20), 90% of  whom had new bone formation, suggesting that adoles-  cents may have growth ability after disc repositioning  which might reduce facial asymmetry. Mandibular asym-  metry in unilateral disc displacement has been reported in  the literature. Xie et al. [86] reported mandibular asym-  metry in 72% of 165 patients with anterior disc displace-  ment and the severity of the asymmetry correlated with  the degree of disc displacement, disc deformity, and con-  dylar shortening. Therefore, disc repositioning may allow  for condylar bone formation and reduce mandibular asym-  metry that may develop as a result of the displaced disc.  The overall clinical outcomes of disc repositioning sur-  gery are good with reduced pain, improved diet, and  improved range of motion with 94% of patients reporting  improved quality of life [87].   For those patients with discs that are not salvageable, dis-  cectomy is the next step in the surgical pyramid. This  involves removal of the disc and the area surrounding any  perforation in the retrodiscal tissue, and possible replace-  ment of the disc is an option. There are several long-term  studies demonstrating greater than 80% success rates follow-  ing discectomy [88-91] with a few following patients for  more than 20 years [92—94] with almost complete resolution  of pain and restoration of normal diet. A 5-year follow-up  study of discectomy without any disc replacement reported  87% of patients fulfilling the criteria for success with reduced  pain on function and increased mouth opening, although  pain at rest was unchanged [95]. Following discectomy,  radiographs will show altered condylar morphology in the  operated joint, and this is thought to be an adaptive process  of remodeling because the reduced symptoms do not corre-  late with the radiographic changes [96, 97]. While the litera-  ture demonstrates the long-term success of discectomy  without replacement [89, 90], disc replacement options have  been explored in attempts to reduce the crepitation these  patients experience and also with the intent to reduce the    remodeling. Many autogenous, allogeneic, and alloplastic  disc replacements have been tried with varying degrees of  success (Table 63.7), and some such as Proplast have caused  joint destruction necessitating joint reconstruction and  replacement [99]. At the current time, there is a lack of evi-  dence to support the routine use of any disc replacement after  discectomy.   The use of tissue engineering is emerging as a promis-  ing option to repair or potentially replace the diseased tis-  sues of the TMJ and may provide additional treatment  options in the future. Progress has already been made  toward the development of appropriate tools for TMJ tis-  sue engineering. The goal is to develop an approach to pro-  duce new tissues de novo (neotissues) with qualities  similar to the native TMJ. This may be accomplished by  (1) in situ tissue engineering, which involves an acellular  scaffold matrix attracting local cells (cell homing) guiding  the process of regeneration, and (2) ex vivo cell seeding on    the scaffold, which provides enough competent cells to  orchestrate the regenerative process. The second strategy  appears better suited for TMJ regeneration because of its  limited capacities of self-repair and the rapid regeneration  expected [100].    If there are functional problems (mechanically obstructive click, closed lock or subluxation)  Is the disc salvageable with normal morphology?  AND is the posterior joint space sufficient for disc repositioning?    Internal derangement of the TMJ is a common problem  resulting in pain and limited function for some patients.  While the vast majority of patients adapt to the internal  derangement over time or with nonsurgical treatment, sur-  gery may be indicated for those with ongoing problems.  There are no surgical procedures for the TMJ that have a  100% success rate; it therefore makes sense to undertake the  least invasive procedures first. The surgical pyramid pre-  sented in this chapter provides a stepwise progression for  TMJ surgical patients. In the authors’ clinical practice, most  surgical patients begin with a level 1 or 2 arthroscopic sur-  gery and only step up the pyramid if this fails. If the diagno-  sis after arthroscopy is Wilkes II, III, or early IV, phase 2  procedure would be disc repositioning and discopexy if the  disc is intact and has normal morphology and there is suffi-  cient posterior joint space in which to reposition it. In Wilkes  IV and V, phase 2 procedure would be joint debridement and  discectomy (Table 63.8).    Finally, Table 63.9 presents an algorithm and decision  framework that guides the progression through the various  surgical procedures discussed in this chapter.   2. Annandale T. 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Open Access _ This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.  org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropri-  ate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.   The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in  a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.    Hypermobility disorders of the temporomandibular joint  (TMJ) present in two major forms:    ; . ; : e Anterior  The differences between dislocation and subluxation have Me pacenar  been highlighted in Box 64.1. Neda  The condyle may be displaced either anteriorly, posteri- ee  orly, medially, or laterally of which anterior dislocation is the :  e Superior    most common [1]. The incidence of TMJ dislocation consti-  tutes about 3% of the dislocations occurring in other joints of  the body with female predilection. The reported incidence of  TMJ dislocation is 7% with a preponderance in people in the  second and third decades [2].   front of the articular eminence. In contrast, sublux- Dislocation recurring more than once is termed as chronic  ation is the condition in which the dislocated condyle recurrent dislocation. The term chronic protracted disloca-  can be reduced back into the normal position by patient tion is used to describe dislocation persisting for more than |  themselves, without any professional assistance. month, while dislocation present for more than 6 months is    called extra-long-standing dislocation [4].  Based on the direction of displacement [2], dislocation  may be categorized as:  64.2 Classification (Box 64.2)  e Anterior  Dislocation has been classified by numerous methods. Rowe Posterior  and Killey [3] based it on the duration of the dislocation epi-  ° Lateral  sode as: ¢ Superior    Anterior dislocation is the most common type of disloca-  V. B. Krishnakumar Raja (™)) tion due the weakness of the capsule in the anterior region.  Department of Oral and Maxillofacial Surgery, SRM Dental    © The Association of Oral and Maxillofacial Surgeons of India 2021 1381  K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1-15-1346-6_64    Fig. 64.1 Lateral dislocation of condyle, Post trauma, on the right side. (a) Frontal view showing lateral dislocation on right side (b) Posterior    Posterior dislocation occurs following fracture of the  external auditory canal and skull base. Allen and Young  classified lateral dislocation into Type I and Type I. This  type of dislocation occurs in mandibular trauma  (Fig. 64.1a, b):   e Type I refers to lateral subluxation.  ¢ Type II indicated lateral and superior dislocation into the   Superior dislocation results when condyle is pushed into  the middle cranial fossa accompanied by glenoid fossa frac-  ture. Small and round-shaped condyle is predisposed to this  type of dislocation [2].    A multitude of causes have been described in the etio-  pathogenesis of TMJ dislocation including congenital,  iatrogenic, anatomical aberrations, spontaneous, pharma-  cological, neurological, neuromuscular, etc. Proper diag-  nosis of the etiology is important to institute problem-  specific treatment.   Poorly grooved glenoid fossa, shallow/steep  articular eminence, laxity of ligaments and  capsule for more prone for dislocation  Ehlers-Danlos disease    Daily activities which involve wide mouth opening such as  laughing, yawning, and biting may induce TMJ dislocation. It  may also occur spontaneously during epileptic seizures, vom-  iting, yawning, and singing. Trauma is another cause which  might cause posterior, superior, and lateral dislocation in addi-  tion to anterior dislocation [5]. Iatrogenic causes include den-  tal procedures which require wide mouth opening for  prolonged time, intubation procedures, gastrointestinal endos-  copy, and laryngoscopy/bronchoscopy. Anatomical aberra-  tions such as small condyle, underdeveloped glenoid fossa,  shallow/steep articular eminence and laxity of ligaments and  capsule are more prone for dislocation.   Predisposing risk factors include connective tissue disor-  ders such as Ehlers-Danlos disease and Marfan’s syndrome  which predispose to laxity of the joint and hypermobility.  Muscle spasms occur in neurodegenerative or neurodysfunc-  tional diseases, namely, Huntington disease, Parkinson dis-  ease, multiple sclerosis, muscle dystrophies, or dystonias.   Medications which induce dislocation are antipsychiatric  (phenothiazines) and antiemetic (metoclopramide) drugs which  produce unwanted extrapyramidal reactions which eventually  lead to muscular imbalance attributed to dislocation.   Reduced vertical dimension due to loss of posterior teeth  in advanced age may also predispose an individual to dislo-  cation [5].   Though various theories of pathogenesis have been  described in literature, the most accepted was muscular inco-    ordination during mandibular movements. In the initial  stages of mouth closure, elevators are activated prior to the  relaxation of depressors mainly lateral pterygoid which pulls  the condyle forward. This initial dislocation facilitates the  further dislocation [5].    64.4 Clinical Features (Mentioned in Box  64.3; Figs. 64.2a, b, 64.3, 64.4a, b,  and 64.5a, b)   . Tense masticatory muscles are also a characteristic  feature [6]  Unilateral dislocation is associated with deviation    Fig. 64.2 (a, b) Bilateral TMJ dislocation. (a) Before reduction (b) After reduction    64.5 Investigations * TMJ tomogram  Open and closed mouth TMJ images can be obtained in  ¢ Orthopantomogram (OPG) (open and closed) (Fig. 64.6) different slices.  This is the commonly used screening modality for the * Computed tomography(CT)    examination of TMJ. Morphology of condyle, articular Evaluation of the morphology of osseous TMJ compo-  eminence, and joint space can be evaluated. Open mouth nents—condyle, articular eminence and the glenoid  OPG shows the position of the condyle in relation to the fossa—are better assessed with CT.    CBCT facilitates accurate measurement of condylar  height, width, and length as well as inclination of articular  eminence.   ¢ Magnetic resonance imaging (MRI)  MRI demonstrates the soft tissue morphology, particu-  larly disc shape, displacement, and effusion of the joint  frequently associated with dislocation.   ¢ Electromyography (EMG)  EMG evaluates the activity of the muscles which may be  hypoactive, normoactive, or hyperactive.   ¢ Ultrasonography (USG)  Thickness and length of the muscles can be evaluated  both at rest and clenching by USG.    Fig. 64.4 (a, b) Preauricular depression. (a) Before reduction. x—Preauricular depression. (b) After reduction    Fig.64.5 (a, b) Unilateral TMJ dislocation on the right side. (a) Before reduction (b) After reduction    cle spasm persisting for longer duration. In difficult situa-  tions, reduction can be facilitated with the help of local  anesthesia, conscious sedation, and general anesthesia.  Following reduction, a Barton’s bandage, chin strap, or inter-  maxillary fixation is advised for 3-6 weeks to prevent further  dislocation. Several reduction techniques have been  employed with varying rates of success.    Reducing the dislocated condyle poses a great challenge.  Reduction is more complicated with the accompanied mus-   This is the conventional method of reduction of acute dislo-  cation in which physician stands in front of the patient, with  the thumb placed either on the external oblique ridge or on  the lower molars and other fingers positioned along the lower  border of the mandible. A steady downward, backward, and  superior force should be given to reduce the dislocated  condyle. The thumb should be protected either with a plastic  splint or gauze wrapped around it to prevent injury to the  thumb while reducing dislocation.   Gag reflex is induced by probing the soft palate using mouth  mirror. In alert individuals, this reflex relaxes the lateral pter-  ygoid muscle through coordinated neuromuscular activities  which reduces dislocation in natural way.   This method utilizes existing myospasm of the elevators for  reduction. The thumb is placed under the chin, while other  fingers are placed over the occlusal surfaces of lower teeth.    Fig.64.7 Nelaton’s method. A: Thumb intraorally on the occlusal sur-  face lower teeth. B: Other fingers at the inferior border of body and  angle of the mandible    Then upward movement is applied by the thumb, and con-  comitant inferior force is given by other fingers with pivoting  the wrist. The advantage of this technique is that it utilizes  the force created by the muscles of mastication rather than  overcoming this force as in Nelaton’s technique.    64.6.1.4 Extraoral Method [8] (Fig. 64.9a, b)  Intraoral methods described previously have the risk of  human bite in which there are chances of infection transmis-  sion. To overcome this, extraoral method has been described.  In the dislocated mandible, coronoid process comes forward  which is easy to palpate. On one side, the thumb is posi-  tioned over the coronoid process which pushes the mandible  backward, while the other fingers are located over the mas-  toid process to deliver counteracting force (Fig. 64.9a). On  the other side, the mandible is pulled further forward with  the thumb on the malar eminence and rest of the fingers on  the mandibular angle (Fig. 64.9b). Pulling the mandible on  one side with simultaneous pushing of the mandible on the  other side reduces the dislocation on one side first and then  subsequently on the other side. This technique is applicable  in unilateral dislocation as one side is reduced first and then  the other is reduced thereafter.    Fig. 64.9 (a, b) Extraoral method for reduction of dislocation. (a) A: Thumb on coronoid process. B: Other fingers on mastoid process. (b) A:  Thumb on malar eminence. B: Other fingers on angle of the mandible    Dislocation/Subluxation (Box 64.5 and Box 64.6 Management of Chronic Recurrent Dislocation/  64.6) Subluxation  Surgical procedures  1. Capsular tightening procedure  Box 64.5 Management of Chronic Recurrent Dislocation/ (a) Capsulorrhaphy  Subluxation 2. Creation of mechanical obstacle  Conservative (a) Dautrey’s procedure  1. Physiotherapy (b) Glenotemporal osteotomy  2. Intermaxillary fixation 3. Removal of mechanical obstacle  3. Chin straps (a) Eminectomy  4. Barton’s bandage (b) Condylectomy  5. Kinesio taping 4. Creation of new muscular balance  Minimally invasive (a) Temporalis scarification  1. Injection of sclerosing agents (b) Lateral pterygoid myotomy  2. Autologous blood injection (c) Pterygoid dysjunction    Numerous treatment modalities have been described for  TMJ dislocation, as it has multifactorial etiology. Miller and  Murphy [9] proposed a comprehensive list of treatment  options which targeted specific anatomical sites of the joint  that exhibited abnormality: the capsule, eminence, and con-  dylar head.   For practical purposes, the types of management may be  broadly classified based on the degree of invasiveness as:    64.6.2.1 Conservative Methods  Conservative methods may be used following reduction of  dislocation to prevent further dislocation, such as:    Intermaxillary fixation, chin strap, and Barton’s bandage  are done for 4 weeks to induce fibrosis of soft tissues around  the joint so that further dislocation is prevented. Physiotherapy  including ultrasound and infrared therapy are advised to  reduce pain. Isotonic and isometric exercise are advised to  strength the muscle involved in TMJ function [9].   In the year 1970, Dr. Kenzo Kase, a Japanese chiropractor,  first described the techniques of Kinesio taping. The thin  elastic tape acts by lifting the skin which increases the blood  and lymphatic flow, thereby reducing inflammation and  accumulation of pain mediators. It also helps in better mus-  cle function and joint realignment which is utilized in reduc-  tion of TMJ dislocation.   This procedure involves repeated injection of sclerosing  solution into the capsule aimed at fibrosis of the capsule  which would eventually limit the mouth opening. The solu-  tions commonly used to perform the procedure are:    These injections are usually given intra-articularly and in  pericapsular region and can be repeated every 2—3 weeks till  the fibrosis occurs. However, the outcome of this technique  is not satisfactory and is also associated with complications  such as TMJ ankylosis and facial nerve injury [9].   OK-432 which is a streptococcal derivative inactivated by  penicillin G is used as sclerosing agent for the treatment of  TMJ dislocation. A 21-gauge needle is used to inject 1.25  KE/ml concentration of OK-432 into the superior joint space  and pericapsular region. 2 ml of the solution is injected in  each region. This produces fibrosis in and around the joint by  inducing local inflammation and formation of granulation  tissue. Mouth opening is restricted for 4 days following  injection by elastic bandage.   This procedure works by producing fibrosis which restricts  the opening of the mouth wide. It involves injection of  patient’s own blood into the superior joint space and pericap-  sular region following two puncture arthrocentesis. Prior to  the injection of blood into the joint, lavage should be done  using two needles in the superior joint space, and then one  needle is removed. Blood is injected through the other needle  into the joint and around the joint. It may be injected either  unilaterally or bilaterally. It can be given as a single or mul-  tiple injections with intervals.   Platelet rich plasma is a yet another minimally invasive tech-  nique used to treat various Temporomandibular joint disor-  ders. It is prepared from 10 ml of patient’s own blood which  was centrifuged at 3200 rpm for 12 minutes. The 2ml solu-  tion was then injected it to the superior joint space which was  located 10 mm forward and 2 mm downward on the can-  thotragal line. Another Iml of the solution was injected into  the pericapsular tissues. Patients were advised for various  mandibular movements for a minute following injection for  the equal distribution of PRP in the joint. Elastic bandage is  given for a week followed by mandibular exercise advised.  PRP has 3-8 folds concentration of platelets and various  growth factors such as platelet derived growth factor, trans-  forming growth factor beta and vascular endothelial growth  factor which helps in healing of the tissues. In a comparative  study between autologous blood injection and PRP for TMJ  dislocation demonstrated both groups were equally effective  in decreasing mouth opening in TMJ dislocation.   It is also called as regenerative injection therapy. This  involves injection of solutions into the joint to stimulate  regeneration potential. Various prolotherapy solutions are  available such as psyllium oil, glycerin, phenol, etc. of which    Fig.64.12 Injection sites for prolotherapy. A: Posterior joint space. B:  Anterior attachment of disc to lateral pterygoid muscle. C: Most tender  point of masseter muscle    dextrose is the most commonly used solution. 2 ml of  10-50% dextrose can be injected in and around the joint  space. Either single or multiple injections are needed based  on severity of dislocation. This technique is indicated in lax-  ity of the ligaments and capsule. It induces low-grade inflam-  mation which releases growth factors. These growth factors  stimulate fibroblasts which deposit new collagen fibers that  strengthen ligaments and tendons.   The first reported use of botulinum toxin for TMJ dislocation  was described by Daelen et al. in the year 1995. Botulinum  toxin type A weakens the skeletal muscle when injected by  preventing the release of acetylcholine at the neuromuscular  junction. It can be injected into any of the masticatory mus-  cle, but injection into lateral pterygoid muscle is effective  because forward movement of condyle is prevented. The  dosage used is 25-50 units of botulinum toxin. It can be  injected either by extraoral or intraoral route with or without  EMG guidance (Refer Chap. 33 on Botox injections).   A 30-gauge needle is inserted into the skin | cm below the  central zygomatic arch to the depth of 3-4 cm based on the  measurements obtained from computed tomogram of the  patient. The 25-50 units of toxin is deposited into the lateral  pterygoid muscle following aspiration.   Hypodermic needle electrode is inserted in the mucobuccal  fold of distal root of upper second molar directed superiorly  and posteriorly to the depth of 25-30 mm; the position of the  needle in the lateral pterygoid muscle is confirmed by EMG  reading. After aspiration, 25-50 units of toxin is deposited  into the muscle.   The injection should be repeated every 3—6 months as the  action of this toxin lasts within 6 months. Complications of  this technique included dysphagia, dysarthria, and  hemorrhage.   Arthroscopic capsulorrhaphy is done by using either laser or  cautery which produces contractions. Sclerosing solutions  may be injected into the joint and capsule under direct visu-  alization using arthroscopy.   A 1.7mm TMJ arthroscope is introduced into the fossa portal  following the double puncture technique described by McCain.  Once the arthroscope reached the anterior recess, the second  puncture is done using triangulation technique. Deep lesional  burns are created in the oblique protuberance, laterally and the  posterior wall using either bipolar cautery or holmium laser  which causes shortening of the capsule.   The arthroscope is introduced into the joint through infero-  lateral approach, and then the articular eminence is reduced  by electronic shaver which is introduced by triangulation  technique.   The following is a brief description of surgical procedures  which are commonly employed for treating TMJ  dislocation.   Temporomandibular joint is completely covered by capsule  which is attached superiorly from all around the rim of the  glenoid fossa and inferiorly till the neck of the condyle. This  capsule holds the joint components in position, which is later-    Fig.64.13 (a—b) Capsulorrhaphy. Excised margin of the capsule. (A) Capsule is tightened by suturing it to the adjacent soft tissues (B)    ally strengthened by lateral ligament. Lax capsule is consid-  ered as one of the reasons for TMJ dislocation. So, capsular  tightening procedures are done to address this problem.   This procedure was first implemented in the year 1907 by  Perthes who excised a portion of the lateral capsule and  sutured it together to increase the tautness of the capsule and  thus restrain condyle. Later on, many modifications had been  proposed including suturing of the capsule to zygomatic arch  and overlapping of the capsule after making vertical incision  on the capsule [9].   Excessive translation of the condyle which is observed in  dislocation is prohibited by creating impediment in the path  of the condyle. Konjetzny (1921) had used articular disc as a  mechanical impediment by bringing it forward and suturing  it anteriorly. Lindemann and Mayer used articular tubercle to  prevent condylar dislocation by either bending it down or  placing a graft obtained from zygoma [9].    Dautrey’s Procedure [10] (Fig. 64.14, b)  Mayer (1933) created a mechanical obstacle by dislocating a  part of the zygomatic arch down, in front of the articular emi-  nence. Vertical osteotomy of the zygomatic arch and reposi-  tioning the osteotomized arch downward as a mechanical  impediment has been described by LeClerc and Girard in the  year 1943.   In 1967 Gosserez and Dautrey made an oblique osteot-  omy of the arch in front of the articular eminence extending    from posterior-superior to the anterior-inferior direction.  With gentle pressure towards inferior direction, a greenstick  fracture was created at the zygomatico-temporal suture. The  segment was then pushed downwards to create obstruction  for the condylar movement. If this downfractured segment is  unstable, plating can be done to prevent displacement  (Fig. 64.15).    Fig.64.14 (a, b) Dautrey’s procedure. (a) A: Osteotomy of zygomatic arch (b) A: Proximal segment of zygomatic arch. B: Downfractured distal    1. Not suitable for elderly individual as it may cause fractur-  ing of the arch instead of greenstick fracture at the  zy gomatico-temporal suture.   3. Medial escape of the condyle as the width of the zygo-  matic arch is narrow.   Norman [10] described glenotemporal osteotomy as a  definitive technique for dislocation. TMJ is exposed  through any of the open surgical approaches described for  TMJ, without violating the capsule. An oblique osteotomy    on the articular eminence is made, following which the  fragment is gently moved downwards to create a wedge-  shaped defect which is grafted using bone taken from ilium,  calvarium, symphysis, etc. Usually it is not necessary to fix  these grafts as they stay in that wedge-shaped space created  by osteotomy. Miniplates or screws can be placed on the  eminence so that excessive condylar translation is pre-  vented. Long-term results of this technique showed screw  loosening and fracture of the plate.   Sharma et al. [11] added two modifications to the conven-  tional glenotemporal osteotomy. Temporalis fascial flap was  used to strengthen the capsule, and pterygoid dysjunction  was performed to address the TMJ pain due to internal  derangement which coexists with dislocation.    Fig. 64.16 (a, b, c) Glenotemporal osteotomy. (a) A: Articular eminence. (b) A: Osteotomy of articular eminence. (c) A: Chin graft in position.    Eminectomy (Fig. 64.17a, b)  The first reported evidence of eminectomy for the treatment  of TMJ dislocation was performed by Hilmar Myrhaug in  the year 1951. This procedure is generally accomplished  under general anesthesia or local anesthesia, or conscious  sedation has also been used for patients with systemic condi-  tions that prohibit general anesthesia. Though there are many  techniques available to address this condition, this particular  technique may be considered for those patients with neuro-  logical disorder, epilepsy, and advanced age [12].   Hall et al. [13] had studied the eminence configuration  using 38 cadavers. The observations included the following:    Articular eminence thicknesses in anterior and posterior  regions were also mentioned [6]. These measurements pro-  vide guidelines while performing eminectomy procedure to  avoid complications.   According to this technique, the joint may be approached  through any of the incisions indicated for TMJ surgeries.  Following exposure of the eminence, rotary instruments,  osteotome, chisel, or piezo surgery device can be used to  reduce the height of the eminence. Either total eminectomy  or partial eminectomy may be done. Irregular bony surfaces  and edges should be smoothened well. Segami et al. [14]  described arthroscopic eminectomy where double puncture    technique has been used. Motorized shaver was used to  reduce the eminence.   Navigation system has also been used for accurate reduc-  tion of eminence especially on the medial side and superior  surface to avoid intracranial exposure [6].   Eminectomy works by allowing free movement of the  condyle over the eminence so that locking of the condyle is  prevented. There are observations of reduced mouth opening  following eminectomy that might be due to adhesions formed  in and around the joint. This can be performed unilaterally or  bilaterally [6].   The major problem associated with this technique is the  excessive forward movement of the condyle than what is  actually needed which leads to stretching of muscles and  ligaments which is potentially injurious to the articular struc-  tures [11].    Condylotomy and Condylectomy (Fig. 64.18a, b)  Closed condylotomy is a blind procedure in which Gigli saw  is used to cut the condyle as described by Kostecka [2].   Part of the condyle is removed to prevent the obstruction;  at the same time, it allows the free translation of the condyle  along the articular eminence.   Preauricular incision is used to approach the condyle, and  then the condyle is sectioned at the inferior level of the artic-  ular eminence.    ¢ Temporalis Scarification [1]  A portion of the temporalis muscle is removed by this  technique so that the scarring and fibrosis induced by sur-  gery restrict the mouth opening.    Fig.64.19 (a—b) Lateral pterygoid myotomy. (A) Lateral pterygoid muscle (B) Part of the lateral pterygoid muscle excised (C) Barrier is placed    This technique was described by Bowman in 1949. This  procedure may be performed through either intraoral by  making incision along the anterior border of the ramus from  coronoid to the third molar region or extraoral route through  preauricular approach. Dissection is carried out to visualize  the attachment of lateral pterygoid to condyle and capsule,  and the attachment is then severed and then silastic sheet    fixed to the anterior surface of the condyle. This results in  restriction of mouth opening for short period of time.   It is an intraoral procedure done to reduce the activity of the  lateral pterygoid on the condyle so that forward movement of  the condyle is reduced [11].    Intraoral vestibular incision is made in relation to the  upper molars, and dissection is done to expose the postero-  lateral wall of the maxilla and pterygomaxillary suture.  Pterygoid chisel is used to separate the pterygoid plates from  maxilla, so that lateral pterygoid muscle along with ptery-  goid plate is detached.    Box 64.7 Management of Long Standing Dislocation  Conservative  1. Manual reduction  2. Continuous elastic traction using bite block  3. Indirect reduction  (a) Using a wire passing in the mandibular angle  region  (b) Using a hook in the sigmoid notch  Surgical procedures  1. Joint procedures  (a) Condylotomy, condylectomy  (b) Myotomy  (c) Joint prostheses  2. Procedures not involving the joint  (a) Sagittal split osteotomy  (b) Vertical ramus osteotomy  (c) Inverted L osteotomy  (d) Midline mandibulotomy    Initially conservative method is employed to reduce disloca-  tion. Manual reduction is attempted either using local anes-  thesia, sedation, or general anesthesia. Continuous elastic  traction may also be applied with the bite block in the poste-  rior region which might reduce the dislocation [15].   Indirect reduction can be performed by inserting wire into  the mandibular angle region, or bone hook is passed into the  sigmoid notch through a small incision made on the angle  region (Rowe and Killey 1968) [4]. Lewis in 1981 used  Bristow’s elevator for the reduction by giving downward and  posterior force.   In long-standing persistent dislocation, patient might  have functional movement due to pseudo joint formation in  front of the articular eminence. In this scenario, the goal is to  establish the occlusion by osteotomy procedures such as sag-  ittal split osteotomy or vertical ramus osteotomy.   Adekeye (1976) [4] suggested inverted L osteotomy  instead of vertical and horizontal osteotomies due to the coro-  noid hindrance. Lateral and medial surface of the ramus is    exposed either through submandibular incision or intraoral  incision extending from the coronoid process along the ante-  rior border of the ramus to the vestibule of second molar  region. Medial osteotomy (horizontal cut) is performed  4—5 mm above and posterior to the lingula and parallel to the  occlusal plane. Vertical cut is performed from the distal aspect  of the horizontal cut to the mandibular angle. Then the den-  tate segment is manipulated to get the desired occlusion.  Proximal and distal segments are fixed with miniplates.   Other methods such as condylectomy, condylotomy, and  myotomy (as described in previous sections) and TMJ pros-  theses are proposed to treat this condition [4].   Ratten et al. described midline mandibulotomy to reduce  the dislocation [16].   Through the intraoral approach, the mandible is sectioned  in the midline, and then each hemimandible is manipulated  to reduce the dislocation on each side separately. Following  reduction, mandibular midline is fixed with miniplates.    This is a new technique performed for the management of  TMJ dislocation. Intraoral vertical incision extending from  the coronoid process to the molar region is made, and the  coronoid and anterior border of ramus is exposed, and then  coronoid is osteotomized and inferiorly pulled along with  temporalis muscle and fixed with miniplates on the lateral  surface of the ramus. The advantage of this technique is that  the temporalis is stretched to give new muscle balance and  restricts the excessive opening of the mouth.    This technique prevents the dislocation by using two Mitek  screw with attached suture material. One screw is attached to  the zygomatic arch and another to the posterolateral surface  of the condyle, and the sutures are tied together to get the  desired mouth opening. These suture materials act as artifi-  cial ligaments that control condylar movement.    Acknowledgment I would like to acknowledge Dr. Vijitha and Dr.  Logitha for illustrations.    64.8 Case Scenarios Preoperative open mouth OPG revealed bilateral TMJ  dislocation (Fig. 64.20a)  Case 1 (Fig. 64.20a-—d) OPG demonstrates:  e Displacement of condyle out of the glenoid fossa  bilaterally  Patient A 24-year-old male, with complaints of locking of =» Condylar head is antero-superior to articular eminence on  the jaw after wide mouth opening both sides    Fig. 64.20 Case scenario | (a) Pre op “open mouth “OPG showing bilateral dislocation of TMJ. (b) Osteotomy of articular eminence (yellow  arrow). (c) Chin graft sandwiched between segments (yellow arrow). (d) Post op OPG showing increase in the height of articular eminence on right  side    Surgical plan Augmentation of articular eminence by gle-  notemporal osteotomy on the right side. The right side was  chosen for intervention as the symptoms were pronounced  on that side    ¢ Right TMJ was approached through preauricular incision  with temporal extension    OPG demonstrating increase in the height of articular emi-  nence on the right side of TMJ (Fig. 64.20d)    Patient A 54-year-old female, with pain in front of the ear  and difficulty in closing the mouth following yawning   ¢ Displacement of condyle out of the glenoid fossa on both  sides    Surgical plan Inferior repositioning of the coronoid on the  right side. The right side was chosen for surgery as the patient  complained of more pain on that side    ¢ Right coronoid was exposed through vestibular incision  extending from lower second molar to anterior border of  the ramus.   ¢ Osteotomy cut was made from sigmoid notch to anterior  border of the ramus (Fig. 64.21b).   ¢ Trough was created on the lateral surface of the ramus just  below the osteotomy cut.   ¢ Coronoid was pulled down over the trough and fixed with  miniplate (Fig. 64.21c).   Open mouth OPG demonstrating the condyle within the gle-  noid fossa on both the sides and coronoid fixed inferiorly on  the right side    bilateral dislocation of TMJ. (b) Osteotomy of coronoid. (¢) Inferiorly | ular eminence  positioned coronoid fixed with 2 mm miniplate. (d) Post -op “open    . Shakya S, Ongole R, Sumanth KN, Denny CE. Chronic bilateral    dislocation of Temporomandibular joint. Kathmandu Univ Med J  (KUM5J). 2010;8(30):25 1-6.    . Awang MN. A new approach to the reduction of acute dislocation    of the Temporomandibular Joint: a report of three cases. Br J Oral  Maxillofac Surg. 1987;25:244-9.   M, Puche-Torres M, _ Iglesias-Gimilio  ME. Temporomandibular chronic dislocation: the long-standing  condition. Med Oral Patol Oral Cir Bucal. 2016;21:e776-83.    The treatment of temporomandibular joint dislocation—a system-  atic review. Dtsch Arztebl Int. 2018;115:59-64.   eminectomy for recur-  rent dislocation. Atlas Oral Maxillofac Surg Clin North Am.  2011;19(2):189-206.    . Lowery LE, Beeson MS, Lum KK. The wrist pivot method, a novel    . Chen YC, Chen CT, Lin CH, Chen YR. A safe and effective way for    mandibular dislocation: review of the literature and report of a case.  Oral Surg. 1976;42:705.   Norman J, Ede B, Bramley P. A textbook and colour atlas of the tem-  poromandibular joint. London: Wolfe Medical; 1990. p. 136-50.  Sharma R. Modifications to Norman’s procedure for hypermobility  of the TMJ. Med J Armed Forces India. 2012;68(3):231-5.    Iwanaga J, Nakamura Y, Kusukawa J, Tubbs RS. Eminectomy for  habitual luxation of the temporomandibular joint with sedation and  local anesthesia: a case series. Case Rep Dent. 2016;2016:2505864.  Hall MB, Randall WB, Sclar AG. Anatomy of the TMJ articular  eminence before and after surgical reduction. J Craniomandibular  Pract. 1984;2:135—40.   Segami N, Kaneyama K, Tsurusako S, et al. Arthroscopic emino-  plasty for habitual dislocation of the temporomandibular joint: pre-  liminary study. J Craniomaxillofac Surg. 1999;27(6):390-7.  Pradhan L, Jaisani MR, Sagtani A, Win A. Conservative man-  agement of chronic TMJ dislocation: an old technique revived. J  Maxillofac Oral Surg. 2015;14(Suppl 1):S267—70.   Lee SH, Son SI, Park JH, Park IS, Nam JH. Reduction of prolonged  bilateral temporomandibular joint dislocation by midline mandibu-  lotomy. Int J Oral Maxillofac Surg. 2006;35:1054—6.  Krishnakumar Raja VB, Balasubramanian S, Sridharan G, Tarun S,  Panneerselvam E. Inferior Repositioning of Coronoid Process for the  Treatment of Temporomandibular Joint Subluxation/Dislocation.  Ann Maxillofac Surg. 2019;9(2):397-399. doi:10.4103/ams.  ams_137_19   Wolford LM, Pitta MC, Mehra P. Mitek anchors for treatment of  chronic mandibular dislocation. Oral Surg Oral Med Oral Pathol  Oral Radiol Endod. 2001;92(5):495-8.    Autologous Blood and Platelet Rich Plasma in Treatment of  Recurrent Temporomandibular Joint Dislocation. Alex Dent J.  2018;43:101-107.    Open Access This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.  org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropri-  ate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.   The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in  a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.    65.1 Introduction and Etiopathogenesis  Temporomandibular joint (TMJ) ankylosis is defined as  bony or fibrous adhesion of the anatomic joint components  accompanied by limitation of mouth opening, causing dif-  ficulty in mastication, speech, and oral hygiene. This may  also influence symmetry of the facial skeleton, especially  in cases which occur when patient is still in the growth  phase [1].   According to Kaban [2], trauma is the most common  cause (31-98%), followed by local or systemic infection  (10-49%), and lastly any systemic disease (10%). Infection  occurring in the joint commonly occurs due to spread from  otitis media or mastoiditis or from the hematogenous route—  tuberculosis, gonorrhea, scarlet fever, etc. Systemic etiology  may include ankylosing spondylitis, rheumatoid arthritis, or  psoriasis.   Classically, hemarthrosis following trauma is the patho-  genic factor for bone formation in TMJ ankylosis [3].  Condylar trauma may lead to hemarthrosis due to injury to  the periosteum and capsular ligament. When this intracapsu-  lar hematoma organizes, hypertrophic bone is formed from  the disrupted periosteum or metaplasia of non-osteogenic  connective tissue. This may lead to hypomobility, and bony  ankylosis may eventually develop.   Yan et al. in 2014 [4] put forth the hypotheses of hypertro-  phic nonunion. He described the sagittal fracture of condyle  along with displacement of the disc. Herein, trauma also  occurs in the glenoid fossa, thereby establishing the microen-  vironment in the articular surfaces for bone healing.    Electronic Supplementary Material The online version of this chap-  ter (https://doi.org/10.1007/978-98 1-15-1346-6_65) contains supple-  mentary material, which is available to authorized users.    S. Anchlia   Department of Oral and Maxillofacial Surgery, Government Dental  College and Hospital, Ahmedabad, Gujarat, India    © The Association of Oral and Maxillofacial Surgeons of India 2021    When the condylar trauma is recent, mouth opening will  exert a dual effect on new bone formation. This is explained  in Fig. 65.1. Restricted jaw movement is not a determinant  but rather a promoting agent for ankylosis. Injuries to both  the articular disc and the articular surfaces are prerequisites  to TMJ ankylosis.    In ankylosis, TMJ movements may be partially or completely  restricted in opening, protrusion, and lateral excursions.  Palpation of joint movements is better in fibrous than bony  ankylosis. In children even in bony ankylosis, joint move-  ments can be palpated because of stretching in the cranial  sutures.   Ankylosis results in issues with mastication, digestion,  speech, and oral hygiene. This may lead to caries, periodon-  titis, encumbered eruption of mandibular molars, crowding  of teeth, and anterior open bite. Mandibular incisors often  show supra-eruption and labial tipping as nature’s compen-  sation since the mandible is placed much posterior to the  maxilla, thereby reducing lip competence. In severe cases,  the lower lip may be trapped under the maxillary incisors.   As the vertical growth of the ramus is restricted, the lower  face is significantly shortened. The digastric and mylohyoid  muscles produce marked antegonial notching at the inferior  part of the mandible just anterior to the insertion of the mas-  seter and medial pterygoid. Failure of condylar growth  impedes the forward and downward movement of mandible  resulting in localized thickening of the bone at the angle due  to subperiosteal apposition which accentuates the antego-  nion. The mandibular warping is caused due to this, as well  as the obtuse angle between the inferior border of the man-  dible and the base of the skull [5]. The long-standing con-  tractions of the masticatory muscles also give rise to  elongation and thickening of the coronoid process, ramal  shortening, and chin recession.    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1-15-1346-6_65    Fig.65.2 (a) Unilateral ankylosis of the right side, (b) bilateral ankylosis    In unilateral cases, the chin deviates to the affected side  due to restricted mandibular growth on the affected side and  normal growth on the unaffected side. In growing patients,  this may also restrict ipsilateral growth of the maxilla,  although there is normal growth on the unaffected side. In  some cases, the growth of the maxilla on the affected side  may be normal but that on the unaffected side may be excess,  due to uninhibited growth of the normal side. Both these  phenomena result in a maxillary cant, though on opposite  sides.   In bilateral cases, the mandible is visibly retruded, lacks a  chin and the patient presents with an obtuse cervicomental  angle. The posterior maxillary height is shortened, giving  rise to steep occlusal planes. This convex facial profile or the  bird face deformity is also described as the “Andy Gump  deformity.” Andy Gump was a cartoon character with a very  insignificant chin, who first appeared in the Chicago Tribune  in 1917, created by cartoonist Sidney Smith [6].   Worsened aesthetics of their appearance often becomes a  reason for depressive disorders, psychological problems  such as stubbornness, low self-esteem, and an inferiority  complex.   The longer the duration of hypomobility, the more severe  is the muscle atrophy and facial asymmetry. The prognosis  for a favorable outcome with treatment is inversely related to  the number of years of ankylosis.    The presence of retruded mandible and micrognathia in patients  with TMJ ankylosis creates narrowing of the pharyngeal air-  way space (PAS) with mechanical obstruction to respiration,  more so in the supine position and during sleep. This process  forms a complex syndrome of apneic episodes with significant  reduction in the mean oxygen saturation levels and secondary  cardiac and respiratory problems, known as OSAHS [7].  Therefore, for patients in whom the release of TMJ ankylosis is  carried out without the advancement of the mandible for the  correction of OSA, there is worsening of an already compro-  mised airway. In such cases wide mouth opening during post-  operative jaw exercises can lead to upper airway collapse—a  sense of choking, bradycardia, and restlessness or apnea-like  episodes, hence increasing chances of ankylosis [8].    According to Yan et al. [4], the deformed TMJ is character-  ized by an enlarged condyle, thickened temporal bone,  excessive bone formation, and a radiolucent zone in the bony    fusion area. No scattered calcified dots are found in the  radiolucent zone, showing that ossification occurs only in the  existing bones.   Bony fusion is located in the lateral part of the joint with  decreased/absent bone marrow cavity and osteosclerosis.  The medial non-bony fusion area shows the atrophic condy-  lar head and rudimentary joint space. Here, the morphology  of the bone marrow cavity and bone mineral density is simi-  lar to that of normal bone.   Wt et al. [9] demonstrated that in fibrous ankylosis, there  is fibrous tissue intruding into the bone marrow of the con-  dyle as well as degeneration of the condylar cartilage. In  bony ankylosis, there occurs new bone formation on the  rough ankylotic surface of the condyle and slight bone  degeneration.   Ankylosis has been classified by various authors according  to its extent, site, development, heterotrophic bone forma-  tion, symptoms, and most recently, the extent of ankylosis  guiding the treatment plan (Table 65.1).    1. Detailed history, complete clinical examination, profes-  sional photographs, for documenting the:  (a) Age of onset of ankylosis  (b) Type, duration, and extent of ankylosis  (c) Type of joint injury or infection  (d) Maximal interincisal opening  (e) Dental characteristics and occlusion  (f) Type of facial deformity  (g) Previous surgery  2. Routine hemogram and pre-op major investigations  3. Radiological examinations for evaluation of extent of  ankylotic mass, discrepancy of jaws, and treatment plan-  ning (Fig. 65.4)  (a) Orthopantomogram:  (i) Decreased joint space  (ii) Absence/presence of normal condylar and coro-  noid anatomy  (iii) Prominent antegonial notch  (iv) Markings for osteotomy cuts (for distraction)  (b) PA cephalogram:  (i) Chin deviation—Cg-ANS-Me (Crista Galli -  Anterior Nasal Spine - Menton)  (ii) Occlusal cant  (iii) Grummon’s analysis    Fig.65.3 The computerized tomographic features of TMJ bony anky-  losis. The blue circle refers to the bony fusion area located in the lateral  part of the joint; in this area, a radiolucent zone can be observed. The  red circle refers to the atrophic condylar head and rudimentary joint  space located in the medial part of the joint. The green arrow indicates  that bone mineral density and morphology of the bone marrow cavity in  the non-bony fusion area were normal. The white arrows indicate  excessive bone formation around the joint    (c) Lateral cephalogram:  (i) Ramal length: Ar-Go (Articulare-Gonion)  (11) Corpus length: Go-Pog (Gonion-Pogonion)  (iii) Pharyngeal airway space (PAS)  (iv) N perpendicular to Pog (Nasion perpendicular  to Pogonion)   (ii) Any anatomical measurements as and when  required, e.g., size of ankylotic mass, location of  ligula, airway space volume, etc.   (e) CT Angiography may be required to assess the rela-  tionship of internal maxillary artery to the ankylotic  mass. There are chances of the vessel being inside the  bone, especially in re-ankylosis cases.   4. Assessment of OSA may be done using Epworth sleepi-  ness scale, Pittsburgh sleep quality index, and polysom-  nography (PSG) for:    (a) Apneic-hypopneic index (AHI)  (b) Nocturnal desaturation episodes  (c) Average respiratory disturbance index  (d) Average lowest arterial oxygen saturation   5. 3D stereolithographic models printed, with the help of  CT scan, may be used in treatment planning. Patient-  specific surgical guides aid planning, precise control dur-  ing operation, and thus more foreseeable treatment  results.   McNamara’s airway analysis on lateral cephalogram helps to  assess the PAS, CT provides volumetric assessment of the  same, whereas PSG helps to assess the AHI. Moderate to  severe AHI may require delayed extubation/tracheostomy.   Blind nasal intubation was done historically, but it was trau-  matic, unpredictable, and unsafe. Tracheostomy is a trau-  matic experience, but nowadays, awake intubation is  performed using midazolam and fentanyl [10]. Fiberoptic-  assisted nasotracheal intubation has become the gold stan-  dard for such patients.    (a) Bilateral ankylosis release is performed, but RCU recon-  struction for ramal height rehabilitation has not been done.  (b) OSA is severe and release precedes mandibular  advancement.  In these two situations, the mandible may fall back as  there is no posterosuperior stop for the ramus and may  impinge on the airway, causing further increase in OSA.   The main trunk of the facial nerve exits from the skull at the  stylomastoid foramen. Approximately 1.3 cm of the facial  nerve is visible until it divides into temporofacial and cervi-  cofacial branches.   According to Al-Kayat and Bramley (1979) [12], the dis-  tance from the lowest point of the bony external auditory  canal (EAC) to this bifurcation measures 1.5—2.8 cm (mean  2.3 cm). The postglenoid tubercle to the bifurcation mea-  sures 2.4—3.5 cm (mean 3.0 cm). However, the point at which  the upper trunk crosses the zygomatic arch is the most vari-   ¢ Type 1: Minimal bony fusion but extensive fibrous adhesions around the joint   ¢ Type 2: Bony fusion at the outer edge of the articular surface but no fusion on medial area of the joint  ¢ Type 3: Bridge of bone between the mandible and temporal bone   Grades 1, 2, and 3 are further classified as symptomatic (S) and asymptomatic (A)  IV. Recent advances: Dongmei He and Colleagues (2011)    Type of Ankylosis Suggested Treatment Plan  ¢ Type Al: Fibrous ankylosis without bony fusion of joint e Ankylosis release temporalis muscle flap, costochondral graft  ¢ Type A2: Bony fusion on lateral side of joint, residual condyle bigger ¢ Lateral arthroplasty   Based on its development, ankylosis can be classified into three phases:   ¢ Chondral-calcified cartilage phase manifesting abundant chondrocytes, cartilage matrix, and neo-formative endochondral ossification in the  joint space   ¢ Bone-cartilage phase showing compacted bone bridge in the lateral joint gap and cartilage in the medial joint gap    able in terms of distance. It may be anywhere from 8 to  35 mm anterior to the most anterior portion of the bony EAC  (mean 2.0 cm). If the superficial layer of the temporalis fas-  cia and the periosteum over the arch is incised within 8 mm,  one can prevent injury to the upper trunk branches.   However, Miloro et al. [13] showed that the average dis-  tance anterior to bony EAC was 2.12 cm. (1.68-2.49 cm).  His was an MRI-based study as compared to cadaveric dis-  section-based work of Al-Kayat and Bramley.   The temporal branch of the facial nerve emerges from the  parotid gland and crosses the zygoma under the temporopa-  rietal fascia to innervate the frontalis muscle in the forehead.    Postsurgical palsy manifests as an inability to raise the eye-  brow and ptosis of the brow. Damage to the zygomatic  branch results in paralysis to the orbicularis oculi. Nerve  damage may necessitate either tarsorrhaphy or gold weight  implants into the upper eyelid for gravity-assisted closure.  Transcutaneous nerve stimulation may be helpful in cases of  neuropraxia.   The auriculotemporal nerve courses from the medial side of  the posterior neck of the condyle and turns superiorly, run-  ning over the zygomatic root of the temporal bone.    4 (a) Lateral cephalogram, (b) PA cephalogram, (c) orthopantomogram, (d) facial CT scan, (e) facial cone beam CT, (f) volumetric    Preauricular exposure of the TMJ area invariably injures the  nerve. Damage is minimized by incision and dissection in  close apposition to the cartilaginous portion of the external  auditory meatus.    The superficial temporal artery and internal maxillary artery  are the terminal branches of the external carotid artery. In the  preauricular approach, the internal maxillary artery runs  about 3 mm medial to the mid-sigmoid notch.   The most commonly injured artery during temporoman-  dibular procedures is the middle meningeal branch of the  internal maxillary artery. Pogrel [14] in a cadaver study of  structures medial to the temporomandibular joint found the  middle meningeal artery to be a mean of 31 mm (21-43 mm)  medial to the zygomatic arch and a mean of 2.4 mm (2—8 mm)  anterior from the height of the glenoid fossa.   It is the most commonly used incision with many variations.  Classically, the incision begins along the course of the helix,  just in front of the tragus till the attachment of the ear lobule.  Going through the skin and superficial fascia, about 2 cm  above the zygomatic arch, an oblique incision is made  through the superficial layer of temporal fascia. Just above  the arch, the periosteum of the zygomatic arch is incised and  turned forward as one flap with the outer layer of the tempo-  ral fascia, superficial fascia containing nerves, and skin. The  ankylotic mass now stands exposed.    65.5.3.2 Blair (1914)  It is like the Dingman’s incision in preauricular fold, but  unlike the former it bends in the region of the zygomatic arch    External carotid artery Masseteric artery  @©Association of Oral and Maxillofacial Surgeons of India    Fig. 65.5 (a) Surgical landmarks for identifying the location of main  trunk of the facial nerve and the temporal-facial division during tem-  poromandibular arthroplastic dissection. (b) Coronal diagram of the  fascial layers and facial nerve at the level of the temporoparietal fascia.  (c) View from medial aspect of the mandible. Note proximity of middle    meningeal, external maxillary, and masseteric arteries. Care should be  taken to protect these structures at the level of the condylar neck and  sigmoid notch during osteotomies. (d) Relative position of the superfi-  cial temporal artery and vein and the temporal branch of the facial nerve    Fig.65.6 (a) Dingman, (b) Blair’s inverted hockey stick, (¢) Thoma’s, (d) Al-Kayat and Bramley. (e) Popowich’s modification, (f) endaural, (g)  postauricular, (h) rhytidectomy, (i) retro-auricular limb of rhytidectomy incision    like a hockey stick. The disadvantages include an unsightly  scar and possible damage to the frontal branch of the facial  nerve.   The vertical limb is in the preauricular fold but angulated at  45° in the hairline near the bifurcation of the superficial tem-  poral vessels.    65.5.3.4 Al-Kayat and Bramley (1979) (refer  video on Al Kayat Bramley approach in  Chap. 53)  This reverse question mark cosmetically acceptable incision  gives excellent access to the TMJ without causing any damage  to important anatomical structures. It starts superiorly through  the scalp in the temporal region and extends to the inferior  tragus. The superficial layer of the temporalis fascia is identi-  fied and incised at the root of the arch at 45° anterosuperiorly  to avoid branches of the facial nerve. A vertical incision may  be used if the temporalis fascia or muscle is to be used.   This approach to the zygomatic arch and joint gives excellent  visibility with safety. It is longer and wider than the conven-  tional and question mark shaped and begins about a pinna’s  length away from the ear, anteroposterior just within the hair  line, curves backward and downward well posterior to the  main branches of the temporal vessels, till it meets the upper  attachment of the ear.   This was first described by Rongetti in 1954, with the inci-  sion carried in the external ear. The advantages are good aes-  thetics and excellent access to the TMJ. However, the  disadvantages include perichondritis, infection, paresthesia  of the pinna, and deformity of the ear.   The endaural incision is extended in a curvilinear fashion  around the mastoid tip, with an S-shaped extension ending in  a submandibular incision. This allows access to the entire  posterior border of the mandible and allows for identification  of the main trunk of the facial nerve.   First described by Alexander [15] in 1975, its biggest  advantage is that it avoids facial nerve injury and salivary  fistula. However, possible complications include stenosis    Kaban [2] and colleagues described an approach for the  treatment of TMJ ankylosis to minimize the incidence of  re-ankylosis and produce satisfactory movement of the  joint. Their study in 1990 became a landmark management  protocol for the management of TMJ ankylosis (Table 65.2).   Yet again in 2009, Kaban [16] considered the potential  effect of time and growth (i.e., the fourth dimension) on the  outcome of TMJ ankylosis in children and presented another  protocol (Table 65.2).    History Ankylosis release surgeries, 1.e., various ways of sep-  aration of the ramus from the skull have undergone great evolu-  tion during the nineteenth century. Esmarch [17] osteotomized  the angle to release TMJ ankylosis in 1851. The first interposi-  tional material was the pterygomasseteric sling, also developed  by Esmarch. Condylectomy was first advocated by Humphrey  in 1854. Abbe performed the first gap arthroplasty in 1880. But  it was Topazian in the 1960s [18, 19] who signified the impor-  tance of interpositional grafts for reducing re-ankylosis.    65.6.1.1 Gap Arthroplasty  The conventional surgical treatment of TMJ ankylosis by gap  arthroplasty includes complete resection of the ankylotic    1. Kaban’s protocol for management of temporomandibular  joint ankylosis (1990) [2]  (a) Aggressive resection of the ankylotic segment  (b) Ipsilateral coronoidectomy  (c) Contralateral coronoidectomy when necessary  (d) Lining the joint with temporalis fascia or cartilage  (e) Reconstruction of the ramus with a costochondral graft  (f) Rigid fixation of the graft  (g) Early mobilization and aggressive physiotherapy  2. Kaban’s modified protocol for management of TMJ ankylosis  in children (2009) [16]  (a) Aggressive excision of fibrous and/or bony mass  (b) Coronoidectomy on affected side  (c) Coronoidectomy on opposite side if steps 1 and 2 do not  result in MIO of 35 mm or to point of dislocation of opposite  side  (d) Lining of joint with temporalis fascia or the native disk, if it  can be salvaged  (e) Reconstruction of RCU with either DO or CCG and rigid  fixation  (f) Early mobilization of jaw; if DO used to reconstruct RCU,  mobilize day of surgery; if CCG used, early mobilization  with minimal intermaxillary fixation (not > 10 days)  (g) Aggressive physiotherapy    Fig.65.7 (a) Gap arthroplasty, (b) Lateral arthroplasty (LAP), (¢) Esmarch’s procedure    mass with no soft tissue as an interposition between two cut  ends. When a soft tissue is placed between the cut ends, it is  known as interpositional arthroplasty. Gap arthroplasty is a  relatively simple procedure requiring less operative time;  however, it may cause ramal shortening, malocclusion, OSA,  and, most distressingly, re-ankylosis. But it may still be used  in certain adult patients, where the removal of a small anky-  lotic mass would not decrease the ramal height significantly.  Patients are operated under general anesthesia using a  preauricular approach. After the ankylotic mass is exposed,  the upper cut is marked, and the lower cut is placed 1.5 cm  below it. In cases where normal architecture of the joint is  maintained, the lower osteotomy cut is placed from the ante-  rior to the posterior border of ramus just below the sigmoid  notch. In cases where normal architecture is not clear, a cut    is placed 1.5 cm below the lower border of zygomatic arch.  Then the upper cut is completed, and the ankylotic mass is  removed. The osteotomy is directed at 45° to prevent fracture  of middle cranial fossa. The venous plexus if encountered  medially needs only be packed to control bleeding.   A condylar retractor is kept below the ankylotic mass to  prevent injury to the internal maxillary artery. Bone is cut  initially using a bur/saw/piezoelectric unit through two thirds  of its thickness. The remaining one thirds may be removed  with an osteotome. A Piezoelectric unit if used, may cut bone  till its very end. In case of a larger mass, it may also be  removed in pieces. The ipsilateral coronoid process is always  resected. Care is always taken to stop the application of  Heister’s mouth gag intraoperatively just before the opposite  condyle dislocates.    In some patients with longstanding ankylosis, the coro-  noid process of the opposite site becomes hyperplastic. There  may also occur fibrosis of the masseter, which would restrict  jaw movements further. Thus, not only would the contralat-  eral coronoidectomy be required, but the masseter attachment  would also need to be completely dissected off the zygomatic  arch. A coronoidotomy may not be adequate, as it may re  form and attach again to the temporalis and subsequently  cause decrease in mouth opening. An intact disc may not  require another soft tissue interpositional graft but may itself  be mobilized and repositioned into the new glenoid fossa.   R. F. Elgazzar [20] reviewed 101 patients (109 joints)  and, on follow-up, reported that in comparison with other  techniques of ankylosis release, gap arthroplasty had the  least amount of mouth opening. Interpositional arthroplasty  with temporalis gives better results in comparison.   Surgical navigation systems are useful in TMJ ankylosis  surgery as they improve both the safety and accuracy of the  surgery. The distance from the top of the glenoid fossa to the  middle cranial fossa and that from the posterior margin of the  fossa to the anterior border of the bony external auditory  canal can be monitored via the navigation system. A safety  distance of at least 3 mm from the middle cranial fossa and  bony external auditory canal should be maintained to avoid  injury. It reduces the risks of bleeding and CSF leak [21].   This is of historical significance only. Esmarch [22] made a  small incision posterior to the angle of the mandible and dis-  sected the masseter and medial pterygoid muscles off the  bone. A 2.5 cm wide wedge of bone, at the angle of the man-  dible with apex at upper border and base at the posteroinfe-  rior border, was removed. The muscles were then sutured  back.   The disadvantage is that since the osteotomy is in the  ramus, no ramal osteotomy or distraction can be done for  correction of facial deformity. Hence, it is no longer used for  ankylosis release.   Nitzan hypothesized that in Sawhney’s [3] Type II TMJ  ankylosis or He’s Type A2 [23], if the integrity and location  of the displaced condyle and disc can be determined (despite  morphological and positional alterations), both could be pre-  served to fulfill their roles in mandibular growth and func-  tion. Only the lateral part of the ankylosed mass was resected.  Eight young patients were kept under observation for a  period ranging from 6 to 60 months after surgery. She found  significant improvement in facial symmetry and thereby con-  cluded that the residual condyle retained its own growth  potential and helped maintain normal mandibular movement  function and occlusion [24].    Yang and Dongmei He evaluated long-term results after  LAP in nine growing children and concluded that the  residual condyle continues to grow after LAP. This then  decreases the amount of further facial asymmetry [25].    Interpositional arthroplasty with RCU reconstruction is the  procedure of choice in recent times. The procedure consists  of:   (11) Reconstruction of the RCU may be considered from  amongst any of the following in costochondral graft,  coronoid process graft, distraction osteogenesis (DO),  total alloplastic joint replacement.   Early postoperative exercises and appropriate physio-  therapy are essential to prevent re-ankylosis, adhesions, and  soft tissue contracture and to regain normal function of the  muscles. Dynamic mouth opening exercise initiated in the  immediate postop period by achieving pain control using  local infiltration of bupivacaine. Dynamic mouth exercises  would have to be continued for at least 6 months after  surgery.    Historically, it has been the most commonly used material  for interpositional arthroplasty as it is simple in technique  and in the vicinity of the original area of surgery. An inferi-  orly based pedicled composite (fascia and muscle), tempora-  lis myofascial flap is raised supraperiosteally which is finger  shaped and about 5 x 2 cm. The flap is taken either over/  under the zygomatic arch and sutured medially and posteri-  orly. However, its potential disadvantages include an  extended incision, temporal hollowing, increased chances of  facial nerve injury, inability to be used again in cases of re-  ankylosis, and myofascial pain secondary to muscle flap  compression.   Albert and Merril described the use of a posterior tempo-  ralis myofascial flap to prevent a visible anterior flap hollow-  ing [26]. Pogrel and Kaban used an axial patterned temporalis  myofascial flap, based on a branch of the middle temporal  artery [27].    65 Temporomandibular Joint Ankylosis  65.7.2 Dermal Fat Graft (Fig. 65.8a, b, c)    The abdominal dermal fat graft is harvested from the suprapu-  bic area used an elliptical incision of around 7 x 3 cm. The fat  is then de-epithelized to procure a volume of 6-20 ml. About  20-30% excess is taken than the actual requirement. The graft  is folded onto itself with the dermis surfaces apposed.   It can be procured quickly and easily with a hidden scar.  It is easy to sculpt into the gap after ankylosis release.    Minimal heterotopic calcification is the advantage of dermal  fat graft. However, since this is a non-vascularized graft, it  may be prone to resorption.   Dimitroulis presented his study on dermal fat grafts. After  a mean follow-up of 41.5 months, only 1 out of the 13 joints  reported recurrence of ankylosis [28]. Thangavelu presented  a review of eight ankylosed joints treated using full-thick-  ness skin subcutaneous fat grafts and concluded that they  were safe and effective [29].    Fig.65.8 (a) Abdominal fat graft donor site and (b) harvested graft, (¢c) abdominal fat graft in place, (d) harvested temporalis flap, (e) temporalis  flap in place, (f) maneuver for harvesting buccal fat pad, (g) harvested buccal fat pad    After the coronoid process is removed, dissection maybe per-  formed along the anterior border of ramus. The main part and  temporal extension of buccal fat pad are in close approximation  to the coronoid process and tendon of the temporalis. Thus, incis-  ing through the periosteum and fascial envelope of BFP at the  anterior most edge of the coronoid stump/superior most stump of  anterior border of ramus exposes the yellowish buccal pad of fat.   Further blunt dissection is performed to herniate the BFP  into the defect with a little teasing and simultaneous milking  of maxillary buccal sulcus intraorally near second and third  molar region. The main advantage is that its vascularity  would maintain the volume of fat for a longer duration with  minimal resorption.    Gaba et al. prospectively assessed the fate of BFP follow-  ing interpositional arthroplasty in 23 joints. In 18 cases, BFP  was viable even after | year [30]. Refer Chap. 24 for detailed  anatomy of the Buccal fat pad.    The amniotic membrane, being a natural biologic entity, pre-  vents inflammation, reduces scarring, and promotes healing and  re-epithelialization. It also has pluripotent, non-antigenic prop-  erties. Akhter M. et al. used gamma radiation sterilized and  freeze-dried amniotic membranes in 13 patients of TMJ ankylo-  sis and showed that it prevented recurrence of ankylosis [31].    Parko in 1973 first published the use of aural cartilage to  replace the meniscus. The biggest advantage of auricular car-  tilage graft is that it can be harvested from the same surgical  field, remains viable and inert and takes the shape of the gle-  noid fossa.   However, there are studies that have reported adhesions  between the auricular cartilage graft and the condyle, leading  to re-ankylosis.    The goal of RCU reconstruction in TMJ ankylosis includes  restoration of ramal height. This not only avoids occlusal  discrepancies and deviation on mouth opening in unilateral  cases but also anterior open bite in bilateral ankylosis. It also  provides enough bone stock for future jaw corrective surger-  ies. The RCU may not contribute as much to facial aesthetics  but impacts function greatly. In cases where RCU has not  been reconstructed, the jaw deviates laterally when opening  the mouth. When closing the mouth, tangential rather than  vertical striking occurs on the occlusal surfaces, making  mastication difficult.   Most importantly, in bilateral TMJ ankylosis after gap  arthroplasty without RCU reconstruction, there are increased  chances of OSA because the ramus falls back due to lack of  posterosuperior stop. Also, it may be possible that restoring  normal jaw movement and a symmetric mandible will allow  future soft and hard tissue development. This would proba-  bly lead to decrease in facial asymmetry by giving as near  normal anatomy as possible by restoration of growth spurts  (Moss’s functional matrix theory).   The ankylotic mass is recontoured and utilized to reconstruct  the RCU and thereby restore the mandibular ramal height.  All neocondyles after RCU reconstruction are fixed into  position with miniplates/screws in the new glenoid fossa just  2 mm short of the soft tissue interpositional material after  placing the patient into intermaxillary fixation (IMF).   R. Gunaseelan excised the ankylotic mass, recontoured  and reimplanted it, and used it successfully for three cases of  condylar reconstruction [32]. However, only if the ankylotic  mass is resected as a whole (which poses greater risk to mid-    dle meningeal artery) can it be recontoured in an adequate  size to reconstruct the RCU, hence the difficulty in routine  use.   Khadka and Hu first reconstructed RCU using the coronoid  process [33]. Reshaped, the coronoid process provides good  bone of adequate quality and quantity to reconstruct the  RCU. Its membranous origin leads to lesser resorption. Also,  a secondary donor site is not utilized. However, as the coro-  noid is a nonvascular graft, there does exist a very real pos-  sibility of its resorption.   Gagan Mehta and Shadab Mohammad conducted a study  on 20 cases and reported that there did occur resorption of  the coronoid in most of the cases. However, that did not  change mandibular function and occlusion [34].   Another method of using the coronoid process is to use it  as RCU with its attachment to the temporalis kept intact.  Most of the attachment may be stripped of, and only the  anterior part of temporalis may be kept attached to the tip of  the coronoid. It may cause less resorption as it would be a  pedicled graft. Yiming Liu studied 48 patients and compared  free vs. pedicled coronoid process grafts and proved that  pedicled grafts showed less resorption on prolonged follow-  up [35].    65.8.2.3 Costochondral Graft (CCG) (Fig. 65.9c)  Poswillo popularized the procedure for using CCG for TMJ  ankylosis in 1987. In unilateral cases, CCG may be taken  from the fifth rib using a submammary incision. If required  on both the sides, alternate ribs, i.e., fifth and seventh, are  used [36].   CCG has various benefits including its growth potential,  its biological compatibility and the fact that it can remodel to  form a new condyle. However, donor site morbidity, resorp-  tion or excessive growth on the treated side, and inability to  catch up with the speed of growth on the normal side are its  potential demerits. Perrott and Kaban [16] described two  types of overgrowth—(a) linear overgrowth causing an    To maximize the chances of survival rate of CCG, the  following techniques may be followed: meticulous dis-  section of periosteum and perichondrium, harvesting  alternate ribs to prevent pain and pleural tear, retaining  intact periosteum and perichondrium at costochondral  junction, sectioning the chondral before the osseous  part to reduce fracture at the costochondral junction,  and only 2-3 mm chondral portion to prevent  overgrowth.    Fig. 65.9 (a) Ankylotic mass, (b) coronoid graft, (¢) costocondral graft    asymmetric or bilateral prognathism and (b) tumor-like over-  growth causing re-ankylosis.   There are various controversies regarding which ribs and  how much cartilaginous cap should be taken, how to fix,  whether post-op IMF is required or not, and resorption vs.  hypertrophy of the graft. Jean Salash reported that out of 72  cases, excessive growth occurred in 54% and equal growth  occurred in 38% [37].   Hence, CCG may be used for RCU reconstruction in  children less than 8 years of age with facial asymme-    try. The justification is that it may help in growth.  However, if it overgrows, the overgrowth may be  treated like condylar hypertrophy, and the superior  2-3 mm may be cut off.   Children less than 8 years but without facial asymmetry  would probably not need a growth impetus, in which cases, a  coronoid graft would be sufficient. In children more than  8 years of age, vertical ramus osteotomies may be used to  recreate the RCU.   (Fig. 65.10a, b)  Y. Liu [38] used the method of total (Vertical ramus osteot-  omy—VRO) and partial (L- ramus osteotomy—LRO) sliding  osteotomy on the posterior border of the ramus for recon-  structing the mandibular condyle in TMJ ankylosis.   The chances of bony resorption and graft failure of the  newly reconstructed RCU are greatly reduced as this seg-  ment is a pedicled graft with attachment to the medial ptery-  goid muscle and periosteum and is not a free graft. Hence the  height of the ramus is maintained. This also leads to adequate  bone stock for further corrective surgeries if and when so  required.   For the VRO, the cut is made in a vertical direction start-  ing from the sigmoid notch to the inferior border of the  mandible just lateral to the lingula and parallel to the poste-  rior border of the ramus. While retaining an adequate    amount of medial pterygoid, the proximal segment is pushed  upward to recreate the RCU and plated in the new position.  A small triangular chunk of bone just anterior to the osteot-  omy cut is resected to reshape the lower border and man-  dibular angle.   For the LRO, an L-shaped cut is made from sigmoid notch  parallel to the posterior border of the mandibular ramus, just  lateral to the lingula, till 10 mm above the angle of the man-  dible. The osteotomized segment is shifted upward and fixed  with a mini plate creating a gap between the osteotomized  segment and remaining mandibular angle. The coronoid pro-  cess on the affected side is resected, recontoured, and fixed  in that gap with another mini plate. The upper part of the  ramus is then reshaped like a condyle.   LRO and VRO differ in the residual height of the ramus  left after ramal osteotomy. In LRO it is retained, and in VRO  it decreases due to the removal of the step at the inferior bor-    der. Thus, VRO may be performed in cases where a pro-  nounced antegonial notch is present.   However, these osteotomies cannot be performed in  patients less than 8 years because as observed on CBCT, the  amount of bone behind the lingula is generally not enough to  osteotomize the posterior border of the ramus.   (Fig. 65.1 1a, b) (Refer Chap. 87)  In multiple operated patients, scar tissue forms with each  surgery, which may affect angiogenesis due to limited diffu-  sion. Thus, free autogenous tissue grafts, such as costochon-  dral and coronoid grafts often fail in such cases. Hence,  transport distraction osteogenesis is considered as an option    for RCU reconstruction, especially in re-ankylosis cases in  children. The same L osteotomy cut may be used to fix the  distractor.   When RCU reconstruction is performed by transport  distraction, it forms a fibrous/pseudo-disc by compressing  the connective tissue between the transport segment and  the glenoid fossa. This disk decreases the chances of re-  ankylosis [39]. Sharma et al. in 2019 carried out neocon-  dyle distraction in five patients and reported adequate  mouth opening and functional movements in all patients.  None of them reported re-ankylosis [40]. But a long-term  follow-up study found that the height of these condyles  was unstable. Also, these mandibles exhibited some degree  of asymmetry [41].    Fig. 65.11 (a) Transport distraction osteogenesis, (b) shows woven bone formation in place of callus in distracted gap, (c) alloplastic TMJ  replacement with simultaneous release and OGS   (TJR) (Fig. 65.1 1c) method to treat recurrent TMJ ankylosis. It may be accompa-  The alloplastic joint consists of a fossa component and a __ nied by bimaxillary osteotomies for simultaneous correction  ramal component, as a stock or a custom-made prosthesis. of secondary ankylotic deformity as well. Its distinct disad-  Re-ankylotic scar tissue in an adult is best treated by total vantage is the fact that if used in children, it would need to be  alloplastic TM joint replacement. Dongmei He and Yi Hui __ replaced [42].    Mercuri et al. [43] specified the indications of TJR  (Box 65.2).   Based on all the above RCU reconstruction options,  guidelines are proposed for technique of RCU reconstruction  in various clinical situations (Table 65.3).   1. Recurrent fibrous or bony ankylosis not responsive  to the modalities of treatment which have been  hitherto applied   3. Loss of vertical mandibular height and occlusal  relationship due to bone resorption, trauma,  developmental abnormalities, or pathological  lesions   4. Severe inflammation of TMJ involving damage to  its structures and lack of response to other treat-  ment methods.    Situations Technique Justification  1. <8 years (a) With facial Costochondral ¢ Potential for  asymmetry Graft + eventual growth  high ¢ Treat  condylectomy overgrowth  like condylar  hypertrophy  (b) Without  Coronoid graft ¢ Potential for  facial growth not  asymmetry required  ¢ Cannot do  ramus  osteotomy  because of  inadequate  ramal width  2. >8 years (a) With Vertical ramus ¢ Reduces  prominent osteotomy antegonial  antegonial notch  notch  (b) Without L-shapedramus  ¢ Maintains  prominent osteotomy height of ramus  antegonial ¢ Adequate  notch ramal size  3. Re-ankylosis (a) Child Ramal distraction ° Free graft  will not take  in scar tissue  ¢ Alloplastic  joint will not  grow  (b) Adult Total alloplastic ° Best option  TMJ replacement for scarred  tissue    Type I (presence of occlusal cant): treatment planning for both  maxilla and mandible  1. Involved side is normal and other side is excess (<6 mm  deficiency)  (a) Differential maxillary impaction  (b) Mandibular ramus osteotomy  (i) Sagittal split osteotomy  (ii) Inverted L ramus osteotomy  (c) + Genioplasty  2. Involved side is deficient and other side is normal (<6 mm  deficiency)  (a) Differential down fracture and bone grafting of maxilla  (b) Mandibular ramus osteotomy  (i) Sagittal split osteotomy  (ii) Inverted L ramus osteotomy  (c) + Genioplasty  3. 6-8 mm discrepancy in maxilla (6-8 mm in mandible)  (a) Simultaneous maxillomandibular distraction  4. 6-8 mm discrepancy in maxilla (>8 mm discrepancy in  mandible)  (a) Cant correction in maxilla  (b) Mandibular distraction as per type II-4, 5, 6  (c) Simultaneous OGS with TJR  Type II: (with minimal occlusal cant) treatment planning for  mandible alone  . Mandibular ramus osteotomy  . Genioplasty  . Orthomorphic osteotomy  . Orthomorphic distraction  . Unidirectional distraction  . Bidirectional distraction  . Simultaneous OGS with TJR    TMJ ankylosis leads to mandibular deformity of varying  magnitude and morphology in the form of decreased ramus  and/or body length, deviation of chin, retrognathic/microge-  nia, bird face deformity, and narrow PAS leading to OSA  (refer Fig. 68.18). Hence, establishing a single set treatment  protocol for all clinical situations is not possible. Table 65.4  is an attempt to classify and thereby establish treatment  guidelines for different types of ankylotic deformities.    They are indicated for movements of about 6—8 mm. For max-  illa, Le Fort osteotomies and, for mandible, sagittal split oste-  otomy or inverted L ramus osteotomy may be performed.    65.9.1.1 Le Fort | Osteotomy (Refer Chap. 69)  It allows correction in three dimensions including roll, pitch,  and yaw. For vertical maxillary excess, differential maxillary    Fig.65.12 (a) Le Fort I osteotomy, (b) sagittal split osteotomy (SSO), (c) inverted L ramus osteotomy (ILRO)    impaction may be performed, while for vertical maxillary  deficiency, maxillary down fracture may be done along with  bone grafting. Posterior maxillary height adjustments may  also be required.    65.9.1.2 Sagittal Split Osteotomy (SSO) (Refer  Chap. 68)  SSO is useful to differentially settle the occlusion according  to the movement of the maxilla, as well as bring the retrog-  nathic mandible forward. The procedure involves three corti-  cotomies—the lingual horizontal, the buccal vertical, and the  intermediate cuts. This osteotomy is generally done on the  normal side in case of unilateral ankylosis. On the affected  side, ramal contour and condylar anatomy distortions,  reduced height of the ramus and steep mandibular plane  angle make SSO difficult to perform.  65.9.1.3 Inverted L Ramus Osteotomy (ILRO)  (Fig. 68.6)  ILRO can be better utilized for increasing the ramal height.  This technique is advocated in cases which require signifi-  cant counterclockwise movement to increase projection of  the lower third of the face when the ramal anatomy is altered.  The cuts are placed using a submandibular and/or an  intraoral approach, posterior and superior to the inferior  alveolar canal. A horizontal cut is made above and behind the  lingula and then joined to the vertical cut from the inferior  border of the mandible.   and 68.34)  Patients indicated for genioplasty have normal ramal height,  functional occlusion, deficient or normal pharyngeal airway  space, and chin deviation or retrusion up to a maximum of 10  mm, hence minimally deformed cases.   An extended genioplasty is performed with the osteotomy  cuts extending up to the first molar on both sides.  Advancement and translational movements in coronal and  sagittal planes are carried out. Interpositional or onlay bone  grafting may be done so as to achieve further symmetry  wherever required.   Alloplastic chin implants made of PTFE, silicon, PEEK,  or customized titanium are alternatives to the traditional  genioplasty.   Patients who may undergo orthomorphic osteotomies are  the ones having normal ramal height, functional occlusion,  deficient or normal posterior airway space, and chin devia-  tion or retrusion up to a maximum of 10 mm, but this can be    done only in cases of unilateral ankylosis. Most importantly,  the primary indication for this surgery is the presence of soft  tissue depression over the mandibular ramus on the unaf-  fected side resulting in a contour defect. The osteotomy cuts  are placed on the unaffected side.   Paul Salins [44] designed the osteotomy as an eccentric  genioplasty extending from the body to the buccal cortex of  the mandible. The cut changes from full thickness from the  body to the sagittal buccal cortical cut in the ramus. The seg-  ment is then repositioned in such a way that it corrects the  midline, the anteroposterior deficit, as well as the lateral  morphological contour defects Fig. 65.13a.    Traditional bone grafting and orthognathic surgery have dis-  advantages—bony resorption, necrosis, donor site morbidity,  limited advancement, relapse, etc.   Advancement of the mandible using SSO generally is  restricted to a maximum of 10-12 mm. In ankylotic patients,  the mandible requires much greater movements. Kohn et al.  have reported high relapse after SSO [45], especially when  used for advancement of mandible. Patients with ankylosis  may report higher relapse rate than others. All the above  issues may be dealt with DO.   Mandible lengthening with distraction leads to increase in  bone stock of the mandible as well as proportionate and har-  monious growth of the surrounding soft tissues. This bony  regeneration is principally dependent on intramembranous  ossification. Also healing and mineralization need adequate  vascularity. Therefore, the incision to perform the surgery  may be kept as limited as possible.   Early distraction may have beneficial effects, on the facial  harmony as well as on the TMJ. If the anatomy and thereby  function of the soft and hard tissues of craniofacial skeleton  is established early in life, it may be possible to regain as  near normal growth of the face.   Distraction in TMJ ankylosis patients with obstructive  sleep apnea has led to decrease in snoring, daytime somno-  lence, Apnoea Hypopnoea Index (AHI), and oxygen desatu-  ration episodes. The disadvantage however is that the device  may be costly and needs to remain in situ for several months.   This technique was first described by Molina and Monasterio  in 1997 [46]. The first stage of surgery comprises of a Le  Fort I osteotomy and a unilateral mandibular osteotomy. The  distraction device is fixed to the mandible on the affected  site. Under IMF, as the mandible moves forward, the maxilla  comes downward, thereby correcting the cant and, simulta-  neously, the anteroposterior deficiency of the mandible. As  this whole procedure is done under IMF, occlusion is main-    tained. The second stage comprises of removal distraction  device and an additional genioplasty if required.   This is indicated when the occlusal cant is such that there  is vertical maxillary deficiency but with presence of func-  tional occlusion. If the mandible alone is distracted, it may  lead to occlusal disasters, hence the need to keep the patient  under IMF while the distraction is being performed.   As laid down by Manikandan et al. [47] , the concept of  orthomorphic distraction of the mandible is a modification of  Paul Salin’s morphometric osteotomy. It involves the distrac-  tion of mandibular basal bone to correct the asymmetry in all  dimensions, despite a deficient soft tissue capsule. It also  provides more movement than that attainable via  osteotomy.   The osteotomy design is similar to the one used in con-  ventional orthomorphic surgery. Once the osteotomized seg-  ment is mobilized, an internal/external distractor may be  placed. Maintenance of the periosteal attachment at the pter-  ygomassetric sling region brings about a pivotal movement  at the gonion facilitating the lateralization and advancement  of the osteotomized segment. The mechanics of the mandib-  ular asymmetry correction is based on the law of parallelo-  gram of vectors.   Distraction of the chin may be performed either in isolation  or simultaneously with ankylosis release. A case report on  the latter has been published by Gunaseelan et al. [48] in  2007 wherein an extended genioplasty osteotomy was per-  formed and external distractors placed and activated. They  suggested that simultaneous genial distraction and arthro-  plasty may be performed in adults, as the mandible is no lon-  ger growing.   This is advocated in adults because they have functional  stable occlusion. Therefore, distraction of the basal bone of  the mandible without distracting the occlusion bearing seg-  ment will only correct the mandibular deformity and the  OSAS, but not interfere with the occlusion. However, in chil-  dren, dental relationships due to mandibular hypoplasia may  be very severe and therefore this may not be the treatment of  choice. Also, the eruption of the permanent teeth may inter-  fere in osteotomy used in this technique.   Genial distraction is an option to gain larger advance-  ments, although may be limited by an unsightly labiomental  fold as advancement increases.    65.9.2.4 Unidirectional DO (Fig. 65.14a-i)  This procedure is indicated in patients with near normal  ramal height but deficient corpus length, chin retrusion and    deviation greater than 10 mm, and presence of mild to mod-  erate OSA.   For deficient corpus length, osteotomy cut is placed in the  body region, generally between second premolar and first  molar or between first and second molars. If the patient has  not undergone presurgical orthodontics or if distraction is  being performed pre-ankylosis release, the cut depends on  the distance between the roots of the teeth and presence of  impacted teeth. Maria B. Papageorge [49] advised that the  cut should be placed in such a manner that the integrity of  mandibular angle is maintained as it forms a very important  aesthetic component of the face.   According to Samchukoy, the vector of distraction should  always be parallel to the occlusal plane, regardless of the  direction of the osteotomy, to prevent anterior open bite  deformity. Kunz et al. [50] has stated it to be a well-known  complication of mandibular distraction. Unidirectional dis-  traction is contraindicated in patients exhibiting vertical  growth pattern. This is because unidirectional distraction in  patients with a steep mandibular plane angle and substantially  deficient ramal height may again lead to anterior open bite.   Internal distraction has a definite edge over external dis-  traction in terms of aesthetics and patient compliance.  However, chances of postoperative infection are greater with  internal distractors. Also, they have limitations in terms of  the amount of distraction possible.   Unidirectional distractors may be placed through either  intraoral or extraoral approach. Surgical splints may be pre-  pared on 3D-printed models preoperatively. Upon exposure  of the bone, these premarked splints are positioned. Using  them as guides, corticotomy sites and sites for distractor  pins/screws are marked. Buccal corticotomy and lower bor-  der full-thickness cuts are placed. Distractor is fixed and the  osteotomy cuts are completed. In case impacted teeth are in  the way of the osteotomy cuts, they may be removed intraop-  eratively itself.   The distractors are activated to check completeness of the  cuts and then brought back. Latency period is of 5—7 days,  depending on the patient’s age. Larger movements require  larger periods of consolidation to prevent relapse.   After distracting for around 8—10 days, shape of the regen-  erate may be changed (callus molding) during the distraction  process. Complications may include infection, tooth fracture,  change of vector, loosening of pin, anterior open bite, and  parotid fistula, but all can be managed conservatively. Callous  molding can take care of occlusal discrepancies to a large  extent, except that if there is absolutely no overjet. However,  with some amount of overjet present, differential distraction  may be done on the superior and inferior borders of the man-  dible. Herein, with the help of callous molding using IMF  screws/eyelets and elastics, the inferior border may be dis-  tracted more than the superior border.    Fig. 65.14 (a) Uniplanar distractor fixed on the 3D stereolithographic view, (e) post-distraction, frontal view (f) preoperative lateral view, (g)  model with osteotomy cut marked, (b) preoperative lateral cephalo- _ post-distraction lateral view, (h) six-month follow-up lateral, (i) six  gram, (c) post-distraction lateral cephalogram, (d) preoperative frontal month follow-up frontal    Sometimes there may be occlusal locking thereby pre-  venting the distracted regenerate from moving in the direc-  tion that is required. A composite block may be prepared on  the tooth to first disocclude it and thereby get distraction in  the favorable direction. Later occlusion may be regained by  callous molding. The molding of the regenerate substantially  reduces the time required for post operative orthodontics.    65.9.2.5 Bidirectional DO (Fig. 65.15a—g)  Bidirectional distractors are indicated for patients with  severely shortened ramal height as well as corpal (body)  length, requiring vertical as well as horizontal components  of distraction. They are also indicated in cases with increased  mandibular plane angle as well as for patients with moderate  to severe OSA.   Surgical splints are prepared on 3D-printed models. Upon  exposure of bone through a submandibular incision, two  osteotomy cuts are placed on either side. One osteotomy cut  is placed on the ramus and the other in the body region on  either side of the angle, keeping the intermediate segment  between 2.5 and 3 cm to avoid avascular necrosis. The device    is secured to the mandible with six percutaneous pins  (Schantz’ pins)—one pair each at the ramus, angle, and cor-  pus. The same procedure may be used for internal distractors  as well.   The osteotomy site depends on position of teeth, lingula,  mental foramen, and size of the intermediate segment. Vector  of horizontal distraction should be parallel to occlusal plane,  and vector of vertical distraction should be parallel to poste-  rior border of ramus. In bilateral cases, horizontal and verti-  cal components of either side should be parallel to each  other. A 2-3 mm overcorrection is generally advisable.  Callous molding may be used for occlusal adjustments. A  single osteotomy cut may however be used for 3D or multi-  vector distractors, thereby considerably reducing the surgical  difficulty as well as the intraoperative time. Their main draw-  back is their prohibitive cost.   The ankylotic retruded mandible has an inefficient genial  muscular apparatus as well, thereby causing retroglossal air-  way obstruction, therefore, OSAS. Mandibular advancement    Fig. 65.15 (a) Biplanar distractor fixed on the 3D stereolithographic  model with osteotomy cuts marked, (b) preoperative lateral cephalo-  gram, (c) post-distraction lateral cephalogram (marked increase in PAS    can be appreciated) (d) preoperative frontal view, (e) post-distraction  frontal view, (f) preoperative lateral view, (g) post-distraction lateral  view    in such cases has shown 97% success in pediatric and 100%  success in adult patients. Decrease in OSAS may be evalu-  ated by an AHI less than 50% decrease in the AHI with a near  normal peripheral oxygen saturation.    OSA, in terms of AHI and PAS, is the principal factor that  determines the sequence of release and deformity correction,  i.e., whether to release first or distract first (refer Chap. 71  on OSAS and Figs. 71.8, 71.9, 71.10, 71.11, 71.12, 71.13  and 71.14).    Treatment protocols can generally be categorized into single-  stage or multistage treatments. Single-stage treatments insti-  tute ankylosis release and correction of secondary deformities  (in the form of maxillary and mandibular osteotomies or dis-  traction) all together. In the multistage protocol, ankylosis is  released, and deformities are corrected in different stages.    Severe secondary deformities are candidates for multistage  procedures as a single-stage surgery may cause severe mal-  occlusion. Correction of the same would require unrealistic  amount of tooth movement.    Advantages: The multistage protocol is generally better for  patients with significant medical comorbidity. This is so  because a single-stage procedure obviously demands greater  surgical time, thereby increasing the intraoperative risks.  Multistage procedures facilitate early postoperative physio-  therapy and, thus, a more stable postsurgical outcome. Also,  the relapse monitoring is easier.   According to Lépez et al. [51], mandibular distraction should  be performed after ankylosis release, as only then would be  complete growth potential of the mandible be known.  Releasing the ankylosis first would ensure adequate food  intake, preparing the patients for subsequent, more complex  surgeries. Also, surgeons could then formulate customized  treatment plans based on individual clinical requirements and   Some surgeons recommend that distraction may be first used  to restore the length and projection of the mandible. Later  arthroplasty may be followed by orthognathic surgery to  obtain mouth opening and settle the occlusion.   Advantages: The mandibular bone deficiency and the air-  way volume are both increased simultaneously. The subse-  quent intubation is much safer. Secondly, for patients with  OSA, this treatment sequence reduces the incidence of post-  operative airway issues—if ankylosis is released first, as the  mandible falls back specially in bilateral cases, the already  reduced airway space then gets further reduced, requiring  reintubation or emergency tracheostomy. This incident can  be avoided if distraction proceeds release.    Patients with mild to moderate dental and skeletal deformi-  ties are ideal candidates for single-stage procedures. The  minimal malocclusion may be treated by orthodontics alone.  In these such cases, ankylosis release along with facial aes-  thetic surgeries which do not involve the occlusion may be  performed, e.g., genioplasty, mandibular recontouring, and  alloplastic implants.    Advantages: This corrects the restricted mouth opening as  well as the secondary deformity simultaneously and avoids  further surgeries. It provides low cost, immediate satisfac-  tion, particularly in patients with psychological issues, and  mild OSA.    Disadvantages: Maxillomandibular fixation often required  after orthognathic surgery interferes with postoperative  mouth opening exercises and therefore increases the chances  of re-ankylosis. In case of internal distraction devices, there  still arises the need for a second surgery to remove it. Also,  the effect of distraction may be unsatisfactory because of  the unstable condyle—if the osteotomy is placed in the  ramus, the proximal segment may go up into the gap created  after ankylotic mass removal, cause loss of vector and  thereby re-ankylosis. Thus, to prevent this complication,  while performing concomitant release and distraction, oste-  otomy cut may be placed only anterior to the angle, in the  body region.    Another potential complication is the interference between  physical exercises and distraction. A pseudo-joint may be  formed in the callus area when the patient exercises, with the  mouth opening force being directed toward the callus instead  of the newly released joint. To prevent this complication,  intensive active mouth opening exercise with wooden sticks/  heisters may be started from postoperative day 1 itself. Mouth    opening exercise from day 7 onward, i.e., once distraction is  started, should exclude the use of the above.   As mentioned earlier, in patients that exhibit mild dental and  skeletal deformities, aesthetic surgeries not involving the  tooth-bearing segments may be performed.   For the patients with moderate skeletal deformities, SSO  along with ILRO and bone grafts may be used to lengthen  the affected ramus. If necessary, Le Fort I osteotomy may be  used to correct the occlusal cant in unilateral cases or bring  the posterior maxilla down in bilateral cases.   Songsong Zhu [52] performed a study on 27 adult patients  who underwent simultaneous ankylosis release and correc-  tion of secondary deformity as a single surgery. No relapse  occurred.   Yi Hui Hu [42] studied 11 patients where CAD/CAM  technique was utilized as a guide to determine level of  removal of ankylotic mass and placement of TMJ prosthesis.  Simultaneous Le Fort I osteotomy was performed in two  patients guided by digital templates. Results showed that  alloplastic TMJ prosthesis is a reliable treatment for recur-  rent ankylosis. The CAD/CAM technique produces accurate  therefore stable results.   Many cases would require a custom-made prosthesis,  typically fabricated with a stereolithographic model. Ryu  et al. in 2016 reported a case where bilateral TM joints were  replaced with a custom-made TMJ prosthesis. Virtual surgi-  cal planning (VSP) and STL model simulation helped in  placing the mandible in a new improved occlusal and aes-  thetic profile [53]. This has become a routine procedure now  in adult patients, i.e., custom-made joints based on VSP  along with simultaneous OGS.    65.10.2.2 Single-Stage Release with DO  Simultaneous interpositional arthroplasty with DO for TMJ  ankylosis, apart from increasing the length of the mandible,  leads to the correction of gross facial asymmetry and mid-  line shift and provides space for eruption of hitherto  unerupted teeth. It helps reduce treatment time and need for  an additional surgery and also alleviates the need for sec-  ond tracheostomy, if the fiberoptic intubation is not  possible.   Only unidirectional distraction in the mandibular body (in  patients with AHI 15-30) may be performed along with  release. If bidirectional distraction is performed, after plac-  ing the arthroplasty cuts, if two more cuts are placed in the  body and the ramus, there are increased chances of avascular  necrosis of the segments. Thus, bidirectional distraction may    not be performed along with release; it may be performed  either pre- or post-release, unless a 3D distractor is being  used.   Krishna Rao et al. [54] performed a study on six patients  and concluded that simultaneous release with DO should be  used to correct ankylosis with facial asymmetry and reported  satisfactory cosmetic correction of deformities. Girish B  Giraddi et al. [55] performed a similar study with nine cases  and concluded that it not only corrects the facial deformity  but also saves the trauma of a second difficult intubation.   Lopez and Dogliotti [51] in 2004 asked a pertinent  question—“Is it reasonable to perform ankylosis release  and mandibular distraction simultaneously without know-  ing which patients will be able to experience growth with  time? In that case it would be necessary to predict growth  to apply the exact amount of mandibular distraction for  obtaining stable results.” This question can now be  answered—in children, the only indications for simultane-  ous release with distraction would be moderate to severe  OSA, with AHI 15-30 (however with normal ramal height)  and extreme facial deformity causing issues with the  child’s psyche.   Most literature till date has either been looking at ankylosis in  isolation from facial asymmetry and has been dealing with  only ankylosis release or facial deformity as staged events or  has been looking at correcting one of the biggest facial defor-  mities, all at one go. There is no middle path mentioned in lit-  erature wherein ankylosis and a substantial part of its related  deformities can be corrected without the following problems—  a supra-major surgery under general anesthesia, extremely  expensive 3D-printed splints and alloplastic joint replacements,  expensive and protracted orthodontics requiring multiple hos-  pital visits from the underprivileged, undernourished patients  living in far-flung areas, and long-term patient noncompliance  for distraction. Also, if osteotomies are performed before the  TMJ attains stability, surgical outcome may be less than satis-  factory as related to aesthetics and occlusion.   A suggested solution for the above problem in adults with  mild to moderate OSA is a single-stage surgery—ankylosis  release by interpositional arthroplasty simultaneously with  genioplasty. It would provide a one-step solution to restora-  tion of function and reasonable aesthetics within a reason-  able amount of general anesthesia time, no occlusal  discrepancies, no compliance for distraction, and no need for  orthodontics. Most importantly, it would not interfere with  any other secondary corrective procedure later, if the patient  so desires.    The author has conducted a study on 43 ankylosed  joints & set forth single-staged treatment guidelines—  ankylosis release, RCU reconstruction, and extended  advancement centering genioplasty for increase in mouth  opening, restoration of ramal height, and improvement in  facial asymmetry as well as OSA. Average mouth opening  at maximum follow-up of 20 months was 34.36 mm with  no reported recurrence. Average increase in N perpendicu-  lar to Pog was 7.16 mm, average decrease in neck-chin  angle and labiomental angle was 31.6° and 35.4°; respec-  tively, average increase in PAS was 2.92 mm. Average 50%  improvement of AHI was seen in all 18 patients who had  OSA [56].    PAS (mm) AHI Rating  >8 <5 Normal  8 5-10 Mild sleep apnea  5-7 15-30 Moderate sleep apnea  <4 >30 Severe sleep apnea    1. Issues in primary surgery  (a) Incomplete appreciation of the extent of the deformity  (i) Unilateral or bilateral  (ii) Length of the coronoid process  (b) Anaesthesia-related issues  (i) Excessive bleeding during fibreoptic intubation  (ii) Emergency tracheostomy  (c) Intra- and immediate postoperative issues  (i) Surgical mishaps  1. Nerve traction  2. Inadequate exposure of the bony block  3. Bleeding from pterygoid venous plexus  4. Injury to the internal maxillary artery  (ii) Failure to achieve adequate mouth opening  1. Ipsilateral joint release — ipsilateral coronoidectomy  — contralateral intraoral coronoidotomy  (iii) Severe bradycardia on mouth opening  (iv) Postoperatively open bite after bilateral arthroplasty/  coronoidectomy  (d) Intermediate and long-term issues following primary  surgery  (i) Re-ankylosis—reasons  1. Incomplete or inadequate primary release  2. Inadequate mouth opening exercises  Gi) Growth alterations of costochondral graft  2. Issues related to secondary surgery of deformities  (a) No control of movement of proximal segment  (b) Careful calculation of the vector    ¢ Traditionally, TMJ ankylosis and its associated microgna-  thia have been treated in multiple stages. Rehabilitation of  mandibular function, prevention of re-ankylosis, and pro-  motion of mandibular growth have been the main aims of  treatment. The treatment has now advanced from only    ankylosis release to total joint replacement as well as  facial deformity correction, all simultaneously as far as  possible.   ¢ The patient at the time of presentation itself is looked at  holistically. A more nuanced decision tree for treatment  planning is formulated, be it for release, new joint recon-  struction, distraction, osteotomies, or the sequencing of  release vs. facial deformity correction. The most critical  deciding factor in the treatment planning is obstructive  sleep apnea, and the key for successful treatment is appro-  priate planning at each stage.   ¢ Therefore, just because in the past, we were releasing all  ankylosis first and doing corrective surgeries later, we  cannot continue doing the same; albeit neither can we dis-  tract all patients first because that is the latest fad. An  extensive review of literature as well as the vast experi-  ence of the author has helped lay down guidelines for  most clinical scenarios of varying magnitude of deformi-  ties in TMJ ankylosis.   e Ina few patients, some degree of facial imbalance may  continue to persist even after surgical interventions.  Additional aesthetic surgery, such as malarplasty reshap-  ing of the chin, angle and lower border of the mandible,  may be required to achieve the best results [57].   e Since TMJ ankylosis is generally a disease of the  underprivileged and socioeconomically backward  strata of society, it should be noted that the deformity  cannot be the only criteria to select the surgical pro-  cedure. Patient’s preference, the treatment cost, and  compliance also need to be taken into consideration.  Some patients are more concerned about their mouth  opening and aesthetics rather than their occlusal  disharmony.    Acknowledgment I wish to convey my deepest thanks and sincerest  gratitude to my resident Dr. Hrushikesh Gosai, without whose observa-  tions, comments, and technical expertise this manuscript would have  not been possible. A mere word of thanks is not sufficient to express the  unflinching support and inestimable aid of my staff Dr. Jigar, Dr. Utsav,  and Dr. Bipin and my residents Dr. Hiral, Dr. Philip and Dr. Nisha dur-  ing the preparation of this chapter. I would be failing in my duty if I did  not recognize the contribution of my biggest teacher in TMJ ankylosis,  my Ex-Hod Dr. Babu Parmar.    A 23-year-old male patient presented with unilateral right-  sided bony ankylosis with retruded and deviated chin with  body and ramal length near normal. So, the patient was  planned for advancement centering genioplasty and onlay  bone graft along with TMJ ankylosis release.    A 14-year-old male patient presented with facial asymmetry  secondary to TMJ ankylosis with moderate OSA.  Cephalometric analysis revealed deficiencies in the length of  the mandibular ramus and corpus of the right side and the  corpus alone on the left side. So, he was planned for biplanar  distraction on right side and uniplanar distraction on left side.    Fig. 65.16 (a-h) Case 1 Right side TMJ ankylosis (a) Preoperative postoperative mouth opening, (g) preoperative orthopantomogram, (h)  frontal view, (b) preoperative lateral view, (c) preoperative mouth open- _ postoperative orthopantomogram (note the genioplasty and onlay bone  ing, (d) postoperative frontal view, (e) postoperative lateral view, (f) graft fixations)    Fig. 65.17 Case 2 (a) Preoperative frontal view, (b) preoperative lat-  eral view, (c) postoperative frontal view, (d) postoperative lateral view,  (e) Pre-distraction PA cephalogram, showing implant on the right side    1. Sporniak-Tutak K, Janiszewska-Olszowska J, Kowalczyk  R. 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Open Access This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.  org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropri-  ate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.   The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in  a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.    66.1 Introduction  Over the last four decades, the scientific foundations for the  art of changing facial appearance and improving orofacial  function through orthognathic surgery were laid, and the  value of treatment to improve lives is undisputed. The main  treatment objective is currently not limited to achieving  short-term improved occlusal function but also enhanced  facial aesthetics and an open airway. Orthognathic surgery  requires the combined skills of the specialities of orthodon-  tics and oral and maxillofacial surgery; however, there  remain major limitations relating to the uneven geographical  distribution of experienced dedicated clinicians and financial  barriers to the correction of dentofacial deformities. The  treatment of some malocclusions combined with mild skel-  etal disharmony is possible by orthodontic compensation of  the dentition with compromised facial aesthetics. Borderline  cases therefore require meticulous assessment before finally  deciding on orthodontic treatment alone or a combination of  orthodontics and surgery as treatment approach.    J. P. Reyneke (4)  Director of The Center for Orthognathic Surgery, Mediclinic, Cape  Town, South Africa    Department of Oral and Maxillofacial Surgery, Faculty of Health  Sciences, University of the Western Cape, Cape Town,  South Africa    Department of Oral and Maxillofacial Surgery, University of  Oklahoma, Oklahoma City, OK, USA  e-mail: johanrey @ worldonline.co.za    C. Ferretti  Department of Maxillofacial and Oral Surgery,  University of Pretoria, Pretoria, South Africa    © The Association of Oral and Maxillofacial Surgeons of India 2021    Which treatment plan to adopt should be discussed with the  patient (and perhaps the parents or spouse) and all the advan-  tages and disadvantages of each approach explained. The deci-  sion may also be influenced by factors such as the orthodontist’s  experience, financial insurance cover, available surgical exper-  tise, and the patient’s attitude and preferences [1].   1. Function. Apart from establishing normal mastica-  tory function, the clinicians should also consider  other problems caused by an abnormal jaw rela-  tionship such as speech defects, sleep apnea, attri-  tion of the teeth, periodontal problems, and  temporomandibular joint problems.   2. Stability of results. Definitive orthognathic treatment  is a change for life, and it is important to achieve  dental and skeletal stability following treatment.   3. Aesthetics. Facial appearance is often the patient’s  main concern, but patients are often reticent to  voice these concerns. However, the surgeon should  resist the temptation to determine unilaterally what  a patient’s aesthetic concerns are but should encour-  age the patient to express these.   4. Airway. The impact of jaw malalignment (and its  correction) on the patency of the upper airways is a  relatively recent addition to the treatment consider-  ations in patients with dentoskeletal malocclusion.  The support of the retropharyngeal soft tissues is  determined to a large degree by the position of the  anterior osseous attachments. Inadequate support for    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1-15-1346-6_66    these soft tissues will contribute greatly to the devel-  opment of sleep apnea especially as soft tissue laxity  develops with aging. This consideration may influ-  ence treatment decisions particularly in Class II  malocclusion. For example, we may be loath to  unduly setback a mandible in a young adult due the  future potential for sleep apnea development. Thus,  in double jaw surgery, a treatment plan that favors  greater maxillary advancement or in a single jaw sur-  gery case a maxillary advancement may be prefera-  ble to a mandibular setback. These considerations  add a further layer of complexity to the treatment  algorithm as airway considerations may mean a  compromise of aesthetics and vice versa [2, 3].    The clinical assessment of the face is the most valuable of all  diagnostic procedures and should be performed in a system-  atic fashion. The facial examination should start at the first  instant a clinician meets the patient and continues during the  initial informal discussion. During this period the patient is  not self-aware, and facial function and features will be at  their most natural. The focused facial examination follows  and should be done while the patient is seated comfortably in  natural head posture, the teeth in centric occlusion and the  lips relaxed. The goal of the facial examination is to deter-  mine what components of the face are detracting from facial  harmony and what functional problems may accompany the  malocclusion and to make a tentative diagnosis.   It is helpful to structure the facial examination into frontal  and profile views [4].    Facial appearance when viewed from the front is, not sur-  prisingly, what a patient will value most.  A helpful first step is to assess the facial form.    ¢ Facial form (Fig. 66.la—h)—The relationship between the  facial width and height has a strong influence on facial har-  mony. The ratio of facial width to facial height is more  important than absolute values in establishing the overall  facial type. Attractive faces tend to have proportions that   relationship) should be considered (i.e., short and stocky  versus long and thin). The height-to-width proportion   imately 30% less than the bizygomatic dimension, and the  width and shape of the chin should form a harmonious part  of the overall facial contour. Leptoprosopic faces (long and  narrow) are often associated with vertical maxillary excess,  a narrow nose, mandibular anteroposterior deficiency, nar-  row gonial angles, microgenia, a high palatal vault, and an  anterior open bite (Fig. 66.la—c), while dolichoprosopic  faces (short and square) are often associated with vertical  maxillary deficiency, masseter hyperplasia, wide gonial  angles, macrogenia, and Class III deep bite malocclusions   terms the rule of fifths is a convenient method used to   evaluate the transverse proportions of the face. The face is  sagittally divided into five equal parts, each the approxi-  mate width of the eye, from helix of the outer ears.   — Outer fifths: Is measured from the lateral helix of the  ear to the lateral canthus and is an indication of the  width of the ears. Bat ears can be camouflaged by an  appropriate hairstyle; however, otoplastic surgical pro-  cedures are relatively atraumatic and can improve the  facial appearance dramatically. Otoplasty can be per-  formed at the same time as orthognathic procedures.   — Medial fifths: Are measured from the outer to the inner  canthus of the eyes. The outer border should coincide  with the gonial angles of the mandible. In patients with  long and narrow faces, the gonial angles will fall  medial to this line, while in patients with broad and  square faces, the gonial angles will fall lateral to these  lines. Within these fifths it should be noted that the dis-  tance between the inner margins of the irides of the  eyes should be equal to the width of the mouth.  Abnormal interpupillary and intercanthal distance are  often observed in syndromic patients and can only be  altered by means of craniofacial surgery.   — Middle fifth: Is demarcated by the lines through the  inner canthus of the eyes. In patients with hyper-  telorism, this fifth would be relatively larger than the  others. The ala of the nose (alar base width) should  coincide with these lines, while the nasal dorsum    Fig. 66.1 The relationship between the facial height and width influences facial harmony. The variations of facial form: (a) narrow, (b) long, (c)  tapered, (d) square, (e) round, (f) oval, (g) sharp, and (h) pointed, are demonstrated    should be approximately half of the intercanthal dis-  tance. For patients in whom maxillary advancement  and/or superior repositioning is planned, this measure-  ment should be considered and surgical control of the  alar base may be indicated.    it is important to record deformities in this area as they  may indicate craniofacial syndromes.    below the iris in a relaxed eyelid position. Individuals  with midface deficiency tend to show sclera under the    e Vertical evaluation (Fig. 66.3)—By convention the face is  divided into three parts by horizontal lines adjacent to the  hairline (trichion) to the soft tissue glabella, the nasal base  (subnasale), and the lower border of the chin (menton).  An aesthetically pleasing face should have approximate  equivalence of the three parts.   — Upper third: Deformities in this third can fortunately  often be masked by an appropriate hairstyle; however,    iris of the eye and will tend to have a long narrow nose.  The cheekbone-nasal base-upper lip-lower lip contour  line is a convenient indicator of the harmony of the  structures of the midface (zygoma, maxilla, and nasal  base) with the paranasal area and upper lip. This imag-  inary line starts just anterior to the ear, extends anteri-  orly across the cheekbone, and then curves  antero-inferior over the maxilla adjacent to the alar    base of the nose, ending lateral and slightly below the  commissure of the mouth. The line should form a  smooth, continuous curve (Fig. 66.4a, c). A skeletal  deformity will cause an interruption of the curve, and    the area of interruption in the line is often an indication  of a specific underlying deformity (Fig. 66.4b).    vertical height of the face should have a 5:6 ratio. In    the well-balanced lower third of the face, the upper  lip makes up one third, while the lower lip and chin  composes the lower two thirds. Normal upper lip  length is 20 + 2 mm for females and 22 + 2 mm for  males and measured from subnasale to upper lip sto-    @Association of Oral and Maxillofacial Surgeons of India Association of Oral and Maxillofacial Surgeons of India    Fig. 66.4 (a) Cheekbone-nasal base-lip contour. (b) The interruption of the curve at MxP (maxillary plane) indicates maxillary anteroposterior  deficiency. (c) Correction of the malocclusion establishes a smooth contour line    mion (stomion superius). When the upper lip is rela-  tively short, there will be a tendency to an increased  interlabial gap and excessive upper incisor exposure  with normal facial height. This should not be con-  fused with the same observations in patients with ver-  tical maxillary excess (Fig. 66.8). Normal lower lip  length is 40 + 2 mm for females and 44 + 2 mm for  males. The lower lip may give the false impression of  being short due to a deep bite. It is mandatory that the  interlabial gap and tooth exposure be evaluated with  the teeth in occlusion and the lips in repose  (Fig. 66.8b). A gummy smile is not a definite indica-  tion of vertical maxillary excess as some patients  may have a normal maxillary height but hyperactive  upper lip when smiling. An increased interlabial gap  (more than 3 mm), excessive upper incisor exposure  (more than 4mm), and a gummy smile are typical  characteristics of vertical maxillary excess (Fig. 66.9).  For patients in whom the upper incisors are not visi-  ble under the upper lip, the tooth lip relationship  should be evaluated with the mandible rotated open  until the lips just separate (Fig. 66.8a). Lack of upper  incisor exposure is indicative of vertical maxillary  deficiency and usually occurs in combination with  decreased lower facial height. The height of the lower  face can also be influenced by the height of the man-  dible, and the height of the chin should be noted in  any discrepancy in vertical facial height.    The arbitrary subdivision of the face into vertical thirds  has a critical flaw. The effects of a deformity of one jaw and  the correction thereof may stretch across two conventional  facial thirds.    It is for this reason that the authors believe a more prag-  matic approach to facial aesthetic assessment is to divide  the face into zones of influence, i.e., zones which can be  modified by orthodontics and orthognathic surgery.    The Ferretti-Reyneke analysis (Fig. 66.5) divides the face  into five zones of influence, 1.e., zones of soft tissue facial  integument that are under the influence of the corresponding  underlying skeleton:    ¢ The fore-head zone (i). Extending from trichion (hairline)  to a line connecting the eyebrows across glabella.   ¢ The oculonasal zone (ii). Extending inferiorly from the  eyebrow line to a line extending from the lower border of  the zygomatic arch curving upward to the infraorbital  foramen onto the nose above the supra tip break and con-  tinuing to the opposite side.    ¢ The gnathic complex. This subunit is subdivided into an  upper maxillary component (iii) which extends from the  lower aspect of the oculonasal complex to a curved line  extending along the lower margin of the upper lip (or the  incisal edge of exposed maxillary teeth) to the angle of  the mouth and proceeding in a curvilinear fashion to the  lower attachment of the auricle and a lower mandibular  component (iv) which extends to the lower border of the  mandible and contains in its anterior aspect the oval men-  tal subunit (v) which delimits the soft tissue chin.    It is critical to remember that facial evaluation is not the  search for deviation from the norm of a single subunit but the  search for proportion. For example, a facial form diagnosed  as vertically excessive means it is excessive in relation to its  transverse dimension, not that it is longer than the norm. By  increasing only the transverse or only the vertical dimension,  facial harmony will be lost; however, harmony is re-  established by increasing both the transverse and vertical  dimensions.    The facial midline is the reference line to evaluate the fore-  head (glabella), nasal dorsum, nasal tip, maxillary dental  midline, columella of the nose, philtrum of the upper lip,  mandibular dental midline, lower lip, and the chin (Figs. 66.2  and 66.6). In the initial overall assessment of facial asym-  metry, we should establish whether the asymmetry involves    the chin, the mandible or the maxilla, or a combination of the  structures. Careful assessment of an occlusal cant of the  maxilla is mandatory as it will play an important role in the  correction of the asymmetry. Soft tissue asymmetry, either  primary or secondary to skeletal asymmetry, should be noted.  Finally, symmetry of the nose, orbits, and forehead should be  evaluated (Figs. 66.2 and 66.6).   The face is a three-dimensional structure, and the symme-  try of the face will be influenced by deformities in the verti-  cal, anteroposterior, and transverse planes. Clinical frontal  assessment of the face is however the most critical, and dis-  crepancies should be correlated with posterior facial asym-  metry by noting any transverse, anteroposterior, and/or  sagittal cants in the occlusal plane. The occlusal plane should  be parallel to the interpupillary line, provided there is no  orbital dystopia. Surgical correction of an occlusal plane cant  often corrects facial asymmetry, and the severity of the cant  should correlate with the dental and facial asymmetry. During  treatment planning the clinicians should assess if orthodontic    or surgical correction of dental midlines is required. With  skeletal asymmetry the dental midline should not be orthodon-  tically coordinated but rather aligned in the center of each jaw  to allow surgical correction of the skeletal asymmetry. Keep  in mind that no face is perfectly symmetric.    The lips play an extremely important role in the overall facial  aesthetics, and careful assessment is required. Lip symmetry  should be evaluated in the rest position as well as when the  patient is smiling. Lip symmetry may be influenced by facial  nerve dysfunction, underlying dentoskeletal deformities,  scarring due to previous trauma, congenital clefting, micro-  stomia, macrostomia, or hyperplasia. The lower lip generally  exhibits 25% more vermillion than the upper lip. With the  presence of an accentuated Cupid’s bow, only the upper inci-  sor may be visible under the upper lip and very little or even  no lateral incisor (Fig. 66.7). An interlabial gap of 0 to 4mm  and 1 to 4mm of upper incisor tooth exposure under the  upper lip with the lips in repose are considered pleasing  while the full crown of the incisor exposed when smiling.    Fig. 66.7 An increased interlabial gap with excessive amount of upper  incisor exposure under the upper lip (a). A poorly shaped upper lip (dis-  torted Cupid’s bow) and excessive amount of vermillion excessive  exposure (b)    Note any asymmetry of the lips when smiling (Fig. 66.10).  When vertical skeletal or dental corrections are contem-  plated, the vertical relationship of all four incisors to the  upper lip should be clinically considered. Only the upper  central incisors are visible on a lateral cephalometric radio-  graph and should not be used to plan vertical maxillary  changes (c in Fig. 66.13).    Although it is emphasized that the clinical assessment of the  face is mandatory, the cephalometric analysis of the lateral  cephalometric radiograph has been the predominant method  of profile evaluation. Many orthodontists are accustomed to  using the quantitative data obtained from the lateral cephalo-  metric analysis as the main diagnostic tool. The contempo-    rary orthodontist and facial surgeon rely on facial  proportionality and more subjective aesthetic evaluation cri-  teria than linear and angular measurements. Treatment deci-  sions should rather be made by what is most aesthetically  appealing rather than by what the cephalometric norms indi-  cate. The plethora of cephalometric values available can lead  to confusion and unnecessary complexity. The undermen-  tioned cephalometric measurements are the most useful indi-  cators to confirm a clinical diagnosis.    The angle is measured between the columella of the nose  and the upper lip and should be between 85° and 105°. It is  influenced by the position and angle of the upper incisor  teeth and the anatomy of the nasal columella. Excessive  orthodontic retraction of the upper incisor teeth (i.e., com-    Fig. 66.8 No upper incisor exposure under the upper lip leads to a “toothless” look (a). An increased interlabial gap with excessive upper incisor  exposure suggests vertical maxillary excess (b). The assessment should always be done with the lips in repose    Fig. 66.9 A patient with vertical maxillary excess. Note the increased interlabial gap with the lips in repose (a) and gummy smile (b)    promised treatment for a Class II occlusion) will lead to  poor upper lip support and an increased nasolabial angle.  This will often lead to early wrinkling and an aging appear-  ance of the lip. An over-closed bite will cause an acute  angle, while a hanging columella of the nose will increase  the angle.    This angle is formed by the intersection of the lower lip and  chin measured at the soft tissue of the chin. The angle is a  gentle curve and should be 120° + 10°. The lower lip, the  depth of the labiomental fold, and chin button should form a  smooth and harmonious S-shaped curve with the labiomen-    tal fold dividing the chin into an upper third and lower two  thirds. The angle is acute in patients with Class II dentoskel-  etal deformities due to the everted lower lip or patients with  macrogenia. Individuals with Class III dentoskeletal defor-  mities and the lower incisors retroclined (compensated) or  patients with microgenia will exhibit an obtuse labiomental  angle.    The angle is formed between the lower border of the chin  and a line connecting the lower lip and soft tissue pogonion.  The chin and submental area are considered attractive with  an angle between 100° and 120°.    It is measured from the angle of the throat to the soft tissue  menton. It is only meaningful when this angle is measured  with the patient’s head in natural posture. A length of between  38 and 48mm is considered to be normal and is significant  when assessing mandibular length. This measurement is  helpful for differentiating between mandibular anteroposte-  rior excess and maxillary anteroposterior deficiency. For a  patient with a Class III malocclusion and normal chin-throat  length, maxillary deficiency should be suspected.    Fig. 66.11 (a) The nasolabial angle, measured between the inclination  of the columella of the nose and the upper lip, should be 85°—105°. (b)  Labiomental fold. The lower lip-chin angle should be 130°. However  the general shape of the chin should be considered    The length of the upper lip is measured from subnasale to the  lower border of the upper lip (stomion superius) and should  be 18-22 mm in females and 20—24 mm in males. This mea-  surement should be performed with the lips in repose. During  the planning of tooth-lip relationship, it should be kept in  mind that the upper lip will increase in length with age.    The interlabial gap should be assessed with the lips in repose  and the teeth in occlusion. It is measured between stomion  superius and stomion inferius (0-4 mm). If the lips touch  when the teeth are in occlusion, the upper incisor-lip rela-  tionship should be evaluated with the lower jaw rotated open  until the lips are slightly apart.    This measurement will give the clinician an indication of  facial convexity or concavity and is influenced by the antero-  posterior relationship between glabella, subnasale, and men-  ton. The angle is formed between the upper facial plane  (glabella-subnasale) and lower facial plane (subnasale-pogo-  nion). The angle is recorded above subnasale and expressed  as negative when the angle is ahead of the upper facial plane  (in convex profiles) and as positive when the angle is behind  the upper facial plane (usually in concave profiles). A pleas-  ing facial profile for females will have a facial contour angle  of —13° + 4° and for males —11° + 4°. This measurement will  also be influenced by the height of the maxilla. The mandible  will rotate counterclockwise (upward and forward) with ver-  tical maxillary deficiency leading to a more concave profile,  while it will rotate clockwise (downward and backward) with  vertical maxillary excess leading to a more convex profile.    This important anatomic structure is situated in the middle of  the face, and its important influence on facial aesthetics has  often been neglected by orthodontists and maxillofacial sur-  geons in the past. More focus is placed on the aesthetic eval-  uation of the nose by the fact that the relative nasal aesthetics  can be influenced by orthodontic treatment and certainly by  orthognathic surgery. The fact that rhinoplasty is now con-  sidered to be part of the field of treatment for many orthog-  nathic surgeons has certainly made the careful aesthetic  evaluation of the nose an important consideration. In many  cases nasal reconstruction will form part of the orthognathic  treatment plan, and in some cases, reconstruction can be per-  formed concurrently with orthognathic surgery. The authors  prefer to defer most nasal reconstructions to 6 months after  orthognathic surgery due to the substantial relative effects  orthognathic surgery has on nasal aesthetic.   The amount of nostril show in profile view may be  affected by either a hanging columella or retracted alae  (Fig. 66.14a). The shape of the dorsum should be noted as  normal, convex, or concave. It is important to distinguish  between a large dorsum and a turned-down nasal tip as the  treatment would be entirely different. The relationship  between the lengths of the nasal dorsum and the projection    1.  ©Association of Oral and Maxillofacial Surgeons of India  Fig. 66.12 The lip-chin-throat angle (i). Chin-throat length (ii)  S  ae: \  ew a)  a'  Cc]    Fig. 66.13 Midface height (a’), lower facial height (a”), upper lip  length (b), upper lip vermillion (c), interlabial gap (d), and facial con-  tour angle (e)    of the nose can be evaluated by the method of Goode. assessed from a “worm’s eye” view (Fig. 66.14d). The nasal  According to Goode the length of the nose should be about _ bridge should project about 5—8 mm in front of the globes of  55-60% greater than the projection of the nose (Fig. 66.14b). the eyes. The nasal tip should be noted as narrow, bulbous,  From nasal base to the tip, the ratio of projection should be asymmetric, or normal. The width of the nasal base, the  1-2 (Fig. 66.14c). The nostrils and columella should be acuteness of the supra tip break, the visibility of the nostrils,    Fig. 66.14 Assessment of  nostril show (a). Nasal  projection (CB) to nasal  length (AB), according to  Goode’s ratio:   CB:AB = 0.55:0.6 is normal  (b). Horizontal assessment of  nasal projection: from nasal  base (Nb), the Pn-Sn to  Sn-Nb should be 2:1 (ce).  Nasal base (“worm’s eye’’)  view assessment of the nose.  The general shape of the alar  base should resemble an  isosceles triangle (d)    and symmetry of the columella are important factors to con-  sider when maxillary surgery (especially superior reposition-  ing or advancement) is contemplated. Fortunately, adverse  aesthetic effects as a result of maxillary surgery can be con-  trolled during surgery [4].    As in the frontal evaluation, the cheekbone-nasal base-upper  lip-lower lip curve contour line is also very helpful in the  profile analysis. The line starts just in front of the ear, extend-  ing forward over the cheekbone, downward over the maxilla  adjacent the ala of the nose, and ending lateral to the com-  missure of the mouth. The line should form a smooth con-  tinuous curve, and any interruption may indicate an  underlying skeletal deformity (Fig. 66.15). The variations in  interruptions in the curve and the possible underlying skele-  tal deformities responsible for the soft tissue deformities are  demonstrated in Fig. 66.15b, c [5].    Orbit  The globes of the eye generally project 0-2 mm ahead of the    infraorbital rims, while the lateral orbital rims lie 8-12 mm  behind the most anterior projection of the globes. The bridge    of the nose should be about 7 mm ahead of the globes  although there is a significant ethnic difference in this mea-  surement (Fig. 66.14) [6].    The flatness or fullness of the paranasal areas is an impor-  tant indicator to distinguish between middle third deficiency  and mandibular anteroposterior excess. Another useful indi-  cator of midface deficiency is the ratio of the linear distance  from the nasal tip to subnasale and from subnasale to the  alar base crease. The ratio should be 2:1 (Fig. 66.14). A ratio  closer to 1:1 will indicate maxillary anteroposterior defi-  ciency, while an increased ratio will indicate decreased  nasal projection.    The lips play an important part in the overall aesthetics of the  face and should be carefully assessed before treatment. The  effects of treatment as well as the aesthetic changes that may  take place during the aging process should be considered.  The upper lip usually projects slightly anterior to the lower  lip, and the E-line and S-line are helpful guides to assess the  projection of the lips (Fig. 66.16) [7].    Fig.66.15 (a) The cheekbone-nasal base-lip curve contour. The curve  should be unerupted and smooth in an individual with good facial pro-  portions. (b) The cheekbone-nasal base-lip curve contour. The interrup-  tion of the curve (arrows) indicates maxillary as well as mandibulae    anteroposterior deficiency. (¢) The cheekbone-nasal base-lip curve con-  tour. Following maxillary and mandibular advancement, the curve is  uninterrupted and smooth (arrows)    Fig 66.16 Lip prominence. Li should be 2 + 2mm behind the E-line  (Pn-Pog’). Li — Labrae inferioris and Ls — Labrae superioris should just  touch the S-line (S-line follows Pog’ to the point between Sn and Pn)    The chin is one of the most noticeable structures in the face  and demands special evaluation. The shape of the chin is  more important than the position of pogonion. Chin surgery  should not be considered for patients requiring mandibular  surgery. Performing an advancement genioplasty for a  patient as compromise treatment for mandibular advance-  ment may achieve correct chin projection; however, the bal-  ance and harmony of the chin will be poor. The authors use  seven criteria for the aesthetic profile evaluation of the chin  which also serve as a guide to surgical treatment planning  (Figs. 66.11, 66.12, and 66.13) [8].    1. Height of the chin. The chin height is measured from  lower lip stomion to soft tissue menton and should be  equivalent to two thirds of the lower facial height. The  linear height should be 40 + 2 mm for females and  44 + 2 mm for males. For individuals with deep bites, the  measurement should be performed with the teeth apart  and the lip separated (i in Fig. 66.12).   2. Vermillion exposure. The lower lip vermillion exposure  should be 25% more than the upper lip. The lower lip will  be everted with increased vermillion exposure when the    lower incisors are proclined or in individuals with an  increased overjet (Fig. 66.13).   3. The labiomental fold. The depth of the fold should divide  the chin into an upper third and lower two thirds  (Fig. 66.11).   4. Chin throat length. Patients with mandibular anteroposte-  rior deficiency will have short chin-throat lengths and  vice versa for individuals with mandibular anteroposte-  rior excess. Normal length is considered to be 42 + 6 mm.  This measurement is important when considering setback  or advancement of the chin (11 in Fig. 66.12).   5. Lower lip-chin-throat angle. The angle is considered pleas-  ing at 110° + 8° and tends to be acute in mandibular prog-  nathism and obtuse in mandibular deficiency (Fig. 66.12).   6. S-shaped curvature. The profile of the chin should form a  well-proportioned, harmonious and smooth curve  (Fig. 66.12).   7. The lower lip position. A helpful guide to the lower lip  position is the E-line (aesthetic line). The E-line is drawn  from the nasal tip (pronasale) to pogonion. The lower lip  should be 2 + 2 mm behind the line. The measurement  will be influenced by the projection of the nose and the  anteroposterior position of the chin which should be kept  in mind during this evaluation (Fig. 66.13).    Most of the aforementioned aesthetics parameters can  also be assessed on a lateral cephalometric radiograph; how-  ever, there is no substitute for clinical evaluation of facial  harmony. It is hoped that the short overview of the clinical  assessment of facial aesthetics will increase the reader’s acu-  ity in the treatment of his/her patients. In most instances the  orthodontist is the first professional to see patients with mal-  occlusions. Some of these patients may require skeletal and/  or soft tissue modification incorporated into the treatment  plan, and the responsibility lies with the orthodontist to rec-  ognize the dental, skeletal, and soft tissue problems and then  to appropriately inform the patient. The aesthetic outcome  following orthodontic (and surgical) treatment should be a  priority for the contemporary orthodontist.    The clinical assessment of the face is probably the most valu-  able of all diagnostic procedures. While an astute clinical  diagnosis can be made at the chair side, photographs are  essential for accurate assessment and record purposes. The  face is systematically assessed from a frontal view, profile  view, and three-quarter view. Figures 66.1, 66.2, 66.3, 66.4,  66.5, 66.6, 66.7, 66.8, 66.9, 66.10, 66.11, 66.12, and 66.13  illustrate some angular and linear parameters used during the  clinical assessment of the face.    Cephalometric and panoramic radiographs and dental casts  are essential; however, temporomandibular joint investiga-  tions, Technetium bone scans, hand wrist radiographs, CT  scans, etc. may be required. The lateral cephalometric radio-  graph taken in centric occlusion and the lips in repose allows  the clinician to analyze and evaluate the soft tissue, skeletal,  and dental relations of a dentofacial deformity.    A diagnosis is made following the clinical evaluation of the  patient, a radiographic evaluation and cephalometric analy-  sis, model analysis, and other indicated evaluations. The data  base is used to compile a problem list.    Clear orthodontic and surgical treatment objectives regard-  ing soft tissue, skeletal, and dental structures should be iden-  tified and noted.    Development of a Visual Orthodontic and Surgical  Cephalometric Treatment Objective The lateral cephalo-  metric radiograph tracing is used to develop an orthodontic  visual treatment objective to predict orthodontic tooth move-  ments. This is followed by the development of a surgical  visual treatment objective predicting the required jaw reposi-  tioning and expected soft tissue changes [10].    All the factors identified in the diagnosis and problem list as  well as patient concerns and reasons for considering orthog-  nathic surgery are considered to formulate a final treatment    plan (Flowchart 1). The sequence of treatment and the treat-  ment to be performed by all healthcare professionals con-  cerned are outlined. When defining the treatment plan, a  thorough knowledge of the many types of dentofacial defor-  mities and the treatment modalities available to correct them  is essential.   The flowchart (Fig. 66.17) summarizes the systematic  gathering of data leading to diagnosis and, finally, the devel-  opment of a treatment plan [9-11].   1. Alignment of both dental arches (with or without  tooth extractions)   2. Levelling of both dental arches (in segments or one  piece)   2. Single jaw  surgery—maxillary repositioning  (advancement or setback or superior repositioning  or downgraft and/or segmental surgery or a  combination)    For each of the above surgical treatment categories, the  orthodontist and the surgeon will have specific responsibili-  ties to make the treatment efforts occur smoothly and suc-  cessfully. In most surgeries, conventional treatment planning  using lateral cephalometric and PA cephalometric radio-  graphs and cast model surgery with surgical splint fabrica-  tion is indicated. However the authors use 3D virtual  treatment planning for more challenging surgeries such as  facial asymmetries, rotation of the maxillomandibular com-  plex, etc. [12, 13].    Although the orthodontist and the oral and maxillofacial sur-  geon are the main role players, comprehensive correction of  dentofacial deformities may involve several members of the  healthcare team. The surgeon should understand the orth-  odontic decision-making process, while the orthodontist  must understand the pre- and postsurgical orthodontic  requirements. It is mandatory that the therapeutic manage-  ment is carried out as planned and any problem or change in    treatment plan should be communicated to the treatment  team. Successful and knowledgeable practitioners always  maintain good interprofessional communication and mutual  respect to achieve the best treatment results.    Successful orthognathic surgery relies on understanding and  interpreting a patient’s desires, correlating these with the  diagnosis, and finally developing a treatment plan and exe-  cuting it accurately. While virtual 3D planning has provided    another tool to aid in diagnosis and surgical planning, it  behooves surgeons to continue to develop proficiency in tra-  ditional cephalometry-based treatment planning.    Case 1: A female patient suffering from hemifacial microso-  mia on the left (Figs. 66.18, 66.19, 66.20, 66.21, 66.22, 66.23  and 66.24).   Case 2: A male patient suffering from skeletal Class 3 maloc-  clusion (Figs. 66.25, 66.26 and 66.27)    Fig. 66.18 (a) Frontal view; (b) note the occlusal cant; (c) the mandible swing to the affected side; (d) right side profile view; (e) left side three-  quarter view, note the microtia; and (f) the left side profile view, note the microtia    Fig.66.19 (a—c) Presurgical occlusion, (d) the occlusion swings to the left on mouth opening, and (e) the lower dental midline is displaced to the  left (arrows) and bilateral cross bites (circles)    3D images of the skeletal deformities. Note the absence of the left condyle and mandibular ramus (Kaban type III) (i) absence of  glenoid fossa, (ii) absence of mandibular condyle, (iii) deficient mandibular ramus on the left side, basal view)    Fig. 66.21 The 3D orthognathic virtual surgical plan: Total joint advancement genioplasty. (i) Pre-surgical, (ii) intermediate position  reconstruction on the left, Le Fort I osteotomy correcting of the maxil- after mandibular surgery, (iii) Final position after maxillary surgery and  lary cant, unilateral sagittal split ramus osteotomy on the right, and an _—_genioplasty    Fig.66.22 The 3D surgical plan for patient-matched left alloplastic condyle, mandibular ramus and angle    Fig. 66.23 (a) Presurgical frontal view, (b) postsurgical fontal view. Note the correction of the occlusal cant    Fig. 66.25 (a-e) Frontal, profile, and intraoral views of patient with Class III malocclusion. Patient has paranasal flattening, mandible deviated  to right, and flat facial profile. Negative overjet, Class III dental occlusion, and mandibular midline to the right    Fig.66.26 2D cephalometric analysis and 2D surgical treatment planning. Surgical plan is Le Fort I downslide, mandibular setback, and advance-  ment genioplasty   gery, vol. 1. Philadelphia: Saunders; 1992. oral and maxillofacial surgery. London: Wiley-Blackwell; 2014.  . Hart PS, McIntyre BP, Kadioglu O, Currier GF, Sullivan SM, p. 315-30.   orthognathic surgery patients. Am J Orthod Dentofacial Orthop. ence of the sliding genioplasty. Gainesville: REAeducation. 2018.   2015;147:536—-46. 9. Sarver DM. Esthetic orthodontic and orthognathic surgery. St  . Hernandez-Alfaro F, Guijarro-Martinez R, Marque-Bueno J. Effect Louis: Mosby; 1998.   Maxillofac Surg. 2011;69:E395—400. 11. Arnett GW, McLaughlin RP. Facial and dental planning for ortho-  . Naini FB. Facial aesthetics, concepts & clinical diagnosis, Ch. 14. dontists and oral surgeons. St Louis: Mosby; 2004.   In: The nose. London: Wiley-Blackwell. 2007. p. 214-36. 12. Reyneke JP. Esthetic facial evaluation in: essentials of orthognathic  . Naini FB, Gill DS. Patient evaluation and clinical diagnosis, Ch. surgery. 2nd ed. Chicago: Quintessence; 2011.   12. In: Naini FB, Gill DS, editors. Orthognathic surgery, principles, 13 Swennen GR, Mollemans W, Schutyser F. Three-dimensional treat-    planning and practice. London: Wiley-Blackwell; 2017. p. 199-206.  . Reyneke JP, Ferretti C. Diagnosis and treatment planning for  orthognathic surgery. In: Anderson L, Khanberg K-E, Pogrrel MA,    ment planning of orthognathic surgery in the era of virtual imaging.  J Oral Maxillofac Surg. 2009;67:2080-92.    Open Access This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.  org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropri-  ate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.   The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in  a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.   Treatment philosophies for the management of dentofacial  deformities are varied. Milder forms of dentofacial defor-  mity not manifesting as a significant skeletal discrepancy can  be corrected by orthodontic treatment alone called “orth-  odontic camouflage”, but those presenting with significant  skeletal discrepancy need the skills of both the orthodontist  and the maxillofacial surgeon. Hence, correction of dentofa-  cial deformities has come to be a confederate work between  both specialties. The dentition and maxillomandibular skel-  etal complex (MMSC) are intertwined, and changes to one  will invariably affect the other, especially more so when the  MMSC positional and spatial relationships change. Over the  years many new concepts have evolved in orthognathic sur-  gery, and the odyssey between the surgical and orthodontic  teams is only getting more inseparable and interesting.    Looking back to 1960s when techniques of mandibular and  maxillary orthognathic surgeries were still evolving from the  works of Obwegeser and Trauner, surgeons often performed  the procedures either before orthodontic treatment or well  after the completion of orthodontic treatment, and rarely any  surgeon depended on an orthodontist to move the teeth into  certain relationship before undertaking surgery [1]. With  time it was realized that the natural dental compensations  became a hindrance to the optimal movement of MMSC,  thus compromising the results and final outcome.   Poulton et al. [1] in 1963 reported few cases of excessive  mandibular growth (mandibular prognathism) which were  treated surgically without any pre-surgical orthodontics. In    N. V. V. Reddy (4) - A. Potturi  SVS Institute of Dental Sciences, Mahabubnagar, Telangana, India    © The Association of Oral and Maxillofacial Surgeons of India 2021    the process, the authors observed that the overjet relationship  between the upper and lower anterior teeth limited the  amount of mandibular setback, thereby compromising the  overall treatment outcome. They concluded that proper  alignment of teeth in upper and lower arches is a prerequisite  to get adequate mandibular setback. This proposal had  almost paved the way for the “orthodontics-first” concept for  correcting dentofacial deformities. Worms et al. [2] in the  1970s popularized the concept of “orthodontics first” for all  orthognathic surgeries which led to the split of orthodontic  treatment into two phases: the pre-surgical orthodontics  phase and post-surgical orthodontics phase with an interven-  ing surgical phase.   The pre-surgical orthodontics phase, which essentially  antecedes the orthognathic surgical phase, brings out the  accurate skeletal discordance by decompensating the natu-  ral compensations which have occurred, thereby helping the  surgeon to perform a more precise spatial relocation of the  MMSC during surgery [3]. However, the pre-surgical phase  of orthodontic treatment, also called reverse orthodontics, is  a long-drawn process lasting anywhere between | and  2 years depending on the complexity of the discrepancy [4].  To add to the woes, during this phase there is gradual dete-  rioration of facial form and dental function [5—7]. Worsening  of the facial profile has become a great deterrent for the  patients seeking orthognathic surgery because the very rea-  son for seeking the orthognathic surgery for improving  facial aesthetics stands defeated and therefore fails to  address the patients’ chief complaint. Also, the long preop-  erative preparatory phase can aggravate or initiate other  dental problems like dental caries or periodontal problems.  For all these reasons, the “orthodontics-first” concept can  produce a negative influence on the patient’s compliance [8]  (Table 67.1).    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1-15-1346-6_67   5. Other complications like dental decay, gum recession and root  resorption or root damage    In order to overcome the shortcoming of conventional  orthognathic surgery, a new approach has been conceptual-  ized called “surgery-first orthognathic approach (SFOA)”.   Even though some surgeons expressed the necessity to  reposition the MMSC before performing any orthodontics in  the past, it did not gain much popularity. With the advent of  skeletal anchorage system in orthodontics and rigid fixation  system in orthognathic surgery, the problem of skeletal  relapse due to unstable bony segments during post-surgical  orthodontics has been significantly reduced, paving the way  for popularization of SFOA [8, 9].   Correction of various skeletal deformities like Class II  [10] and Class II [11] and facial asymmetry [12] using SFOA  technique has been reported in the past, and all of them  claimed shortening of the total treatment time as a significant  and greatest advantage over the conventional technique.  William Bell, the “godfather” of orthognathic surgery, dur-  ing one of his clinical rounds with his residents, highlighted  the changing trends in orthognathic surgery by contending  that the present orthognathic surgical procedures remain too  complicated, too invasive, too time-consuming, too expen-  sive, and too unpredictable, and he literally set the tone for  discussing “paradigm shifts in orthognathic surgery” [13].  After the clinical applications of advanced three-dimensional  imaging and office-based surgery, the 2011 symposium on  SFOA created a broader interest in complete elimination of  time-consuming pre-surgical reverse orthodontics and paved  the way for worldwide acceptance of this paradigm shift in  orthognathic surgery [14, 15].   SFOA technique is fundamentally a “‘face-first” approach  wherein the patient’s chief complaint is taken care immedi-  ately by improving the facial soft tissue profile and thereby  increasing the patient’s compliance to overall treatment  (Fig. 67.1). In SFOA, greater part of the dentition remains at  the same position with respect to their respective arches as  there is no pre-surgical orthodontic phase involved.  Following the orthognathic surgery, MMSC will be in a  Class I relationship, yet the upper and lower dentition may  not fit perfectly into occlusion. A treatable malocclusion,  called transitional occlusion, is set at the end of surgery  which can be corrected by the orthodontists. Hence, the    Fig. 67.1 The flow diagram demonstrating fundamental differences  and the order of priority between the SFOA and conventional approach    orthodontist must actively participate in the treatment plan-  ning in SFOA so as to achieve a treatable transitional occlu-  sion at the end of surgery. The orthodontist must be able to  foresee the resulting occlusion even before the surgery, and  this ability to plan and foresee the resultant transitional  occlusion accurately is the linchpin of the entire SFOA tech-  nique. Therefore, in SFOA technique the orthodontic princi-  ples and guidelines must be established in advance so as to  ensure that treatable malocclusions are attained.   Kim JH et al. [8] in their treatise called “Guidelines for  “surgery first” orthodontic treatment” have emphasized cau-  tion when embarking on SFOA technique. The entire plan-  ning process (Fig. 67.2) is laborious since the skeletal  changes should be preconceived and the casts should be  mounted accordingly to determine the anticipated post-  operative orthodontic teeth movements, and, even for the  highly accomplished orthodontic and surgical team, it is    challenging to pinpoint accurately the occlusal relationship  that will balance ideal aesthetic and functional results. It  should be remembered during planning that surgical move-  ment should be adequate enough such that dental decompen-  sation is possible after the surgery. Customarily, the dentition  is bonded/banded and a passive arch wire is placed before  surgery. Active orthodontic tooth movement begins within a  relatively short period of time after the jaw(s) are reposi-  tioned to take advantage on the inherent phenomena called  accelerated tooth movement [8].    It is observed that the orthodontic tooth movement following  orthognathic surgery is rapid and it is significantly rapid dur-  ing initial 4—5 post-operative months. This rapid tooth move-  ment post-surgery is attributed to RAP, and it is observed  with all the three planes, sagittal, vertical and transverse.   It is an established fact that orthodontic tooth movement  is a metabolic event of alveolar bone resorption in the areas  of pressure and bone formation in the areas of tension [16,  17]. In order to analyse post-surgical changes in bone metab-  olism after orthognathic surgery and the corresponding  response in the dento-alveolus, Liou et al. conducted a pro-  spective clinical pilot study in 2011. All 22 adult patients  who participated in their study underwent both maxillary  LeFort I osteotomy and mandibular bilateral sagittal split  osteotomy for repositioning of their jaws. Each of these  patients was evaluated for serum alkaline phosphatase (ALP)  and C-terminal telopeptide of type I collagen (ICTP) before  and after surgery at sequential intervals for up to 4 months  post-operatively [14].   ALP and ICTP are two bone markers which are indicative  of bone turnover rate. ICTP is a bone resorption metabolite  of type I collagen in bone and has been associated with the  activities of osteoclasts [18]. ALP is an enzyme for bone for-  mation and has been found to associate with osteoblasts  function [19]. The results of Liou et al.’s study [14] showed  transient increase in the levels of both ICTP and ALP in the  immediate post-surgical period indicating burst in the activ-  ity of bone remodelling and turnover activity. It was observed  from Liou et al.’s [14] study that the ICTP levels peaked  from 1 week to 3 months and the ALP levels from | to 4  months post orthognathic surgery. This increase in bone  turnover markers in the initial post-operative period is a clear  indicator of high metabolic activity in the bone and therefore  can be used to advantage in shortening the total treatment  time in SFOA.   The RAP is not isolated to SFOA. Even in conventional,  orthodontics-first approach, this phenomenon plays its role  in post-surgical orthodontics. The only difference is that in    conventional technique the surgery is done after the decom-  pensation is achieved. The SFOA technique utilizes the  golden opportunity of RAP by speeding up the decompensa-  tion process which occurs after the orthognathic surgery con-  trary to that in conventional technique. Therefore, in SFOA,  the surgical procedure increases the bone metabolic rate of  dento-alveolus in the first 4 post-operative months, which in  turn accelerates the orthodontic tooth movement. Hence to  make complete use of RAP in SFOA, the post-surgical orth-  odontic tooth movements have to be begun as early as Ist  week and completed by the 4th month.   Though SFOA technique can be employed in any kind of  maxillomandibular skeletal discrepancy, Liou et al. proposed  the following indications in 2011 (Box 67.1) which could  help in easy case selection and will act as a guide for the  beginners.    ¢ The upper and lower dentition are bonded and banded  before the surgery without placing any arch wire in order  to keep the dentition undisturbed and solid during and  after the surgery.   e When planning for SFOA, multiple treatment options  must be taken into account. It is very important for the  orthodontist to plan the resulting occlusion on the preop-  erative model set-up in order to achieve relatively stable  occlusion on the table during surgery.   ¢ The decompensation of the teeth to normal positions and  angulations will be done after surgery, and hence transi-  tional occlusion should allow any orthodontic teeth move-  ment after the surgery. Since the incisors cannot be used  as a guide to foresee the final form of occlusion in SFOA,  the molar relationship can be utilized as a starting point to  come up with a temporary occlusion.   e Cases in which decompensation is not required or  minimal decompensation is required    e For the model surgery, the maxillary and mandibular casts  are positioned in a proper molar relationship and with a  positive overbite. The molar relation could be set up in  Class I in cases of non-extraction or bimaxillary first pre-  molar extraction, Class II] in cases of lower first premolar  extraction and Class II in cases of maxillary first premolar  extraction. Once the molar relationship has been estab-  lished, the overjet should also have been determined.   e The inclination and angulations of upper incisors deter-  mine the pattern of extractions. If upper incisors are  excessively inclined, then premolar extraction needs to be  planned in order to allow post-operative retraction of  upper incisors. As a rule of thumb, if the upper incisor to  occlusal plane angulation is less than 53—55°, extraction  must be considered [20].   ¢ The transverse dimension often creates a special chal-  lenge when performing model surgery in surgery-first  cases. The upper and lower midlines must be coincident  or close to it post-surgery, and proper buccal overjet must  be established bilaterally.   ¢ Once surgery is completed, the post-operative orthodontic  treatment can begin anytime between | week and 1 month  post-operatively in order to take the advantage of RAP.    Envisioning the final dental occlusion based on the pres-  ent occlusion is the key factor in success of SFOA. The  interim transitional occlusion achieved on preoperative  model set-up must be stable enough to allow predictable  splint preparation and skeletal movement. It is highly recom-  mended that at least three point contacts are achieved  between upper and lower teeth when planning for interim  transitional occlusion. In situations where such transient  occlusion cannot be established, it is advisable to commence  some orthodontic movement in order to assuage some of the  interferences and allow for a more stable transitional maloc-  clusion to be established.    e The sagittal decompensation for proclined upper incisors  in a Class III case could be achieved by an anterior seg-  mental osteotomy with removal of the maxillary first  bicuspids or by clockwise rotation of the maxilla by LeFort  I osteotomy to upright the maxillary incisor inclination.   e The anteroposterior decompensation for moderately ret-  roclined and crowded lower incisors in a Class III case  could be achieved by setting up the molars in a Class I  relationship with an excessive incisor overjet, and then  the mandibular incisors could be aligned after the surgery  to obtain the desired overjet.    ¢ The sagittal decompensation for severely retroclined and  crowded lower incisors in a Class III situation could be  achieved by extraction of the lower first bicuspid and  anterior segmental osteotomy, setting up the molars in a  Class III relationship with an excessive incisor overjet,  and then the lower incisors could be aligned after the sur-  gery to obtain a desired overjet.   ¢« A moderate to deep mandibular curve of Spee in a Class III  case is better levelled preoperatively or surgically by ante-  rior segmental osteotomy to avoid the upward and forward  rotation of the mandible post-operatively. Alternatively, the  lower incisors could be intruded, and the upper incisors at  the same time could be extruded post-operatively.    ¢ Fora moderate to deep mandibular curve of Spee and pro-  clined mandibular incisors in Class II mandibular retrog-  nathism, the anterior segment of the lower jaw could be  levelled and intruded surgically through anterior segmen-  tal osteotomy so that the mandible could be advanced  accurately.   e Alternatively, the mandible could be surgically advanced  to an edge-to-edge incisor relationship and without occlu-  sal contact in the posterior teeth, and then post-surgically,  the lower anterior teeth could be orthodontically intruded  so that the mandible rotates upwards and forwards for  posterior occlusal contact and a better chin projection.    The protocol variations between the conventional orthogna-  thic surgery and SFOA can be clearly appreciated in the  Table 67.2 highlighted in Bold fonts. A simulation of pre-    treatment orthodontic treatment  Model mounting and model setup  4. Simulation of orthognathic  surgery  4. Surgical arch wire 5. Surgical arch wire  5. Fabrication of splints 6. Fabrication of splints    surgical orthodontic treatment using model mounting and  set-up will compensate the pre-surgical orthodontic  treatment.    Although the sequence of treatment is similar, different pro-  tocols are being used to prepare the patient for surgery, per-  form the operative procedure, and commence the orthodontic  treatment.   e Sugawara and Nagasaka [10, 11]; E Liou et al. [15]—Just  before surgery    Placement of passive stainless steel arch wires bent and  adapted to each tooth before surgery will preclude any  untoward tooth movement during or immediately after the  surgery. The authors wishing to capitalize on the RAP con-  cept immediately after surgery prefer to place active nickel-  titanium arch wires prior to surgery. Nonetheless, in doing  so, the orthodontist loses an opportunity to observe the sta-  bility of the surgical correction prior to beginning of the  tooth movement. The rapid acceleratory phenomenon not  just influences the tooth movement but also can disturb the  alveolar bone [8].   There are also protocol variations regarding the usage of  surgical splints after the surgery among the various authors.  While some authors suggested the use of the surgical splints  only intraoperatively, others have advocated its use anywhere  between | and 4 post-operative weeks. Nagasaka et al. have  used removable Gelb-type splints post-surgery [10]. Kim’s    preference is to leave the splint in for about | month to | and  a half months post-operatively and if an open bite is observed  to use elastics between the splint and the mini-screws placed  into the bone or to leave the splint for an even longer time  period [8].    ¢ Once the treatment planning and diagnosis is completed,  impressions are made and customary model mounting is  performed with bite registration to scrutinize the present  state of the occlusion.   ¢ In the model set-up, teeth that have adapted by natural  compensation to the existing skeletal discrepancy are  simulated and reorganized into anticipated occlusion sim-  ilar to the preoperative orthodontic treatment plan. All the  teeth on the set-up model are rearranged as if orthodontic  treatment is done in the real patient in conventional  orthognathic surgery technique into the desired preopera-  tive occlusal relationship.   ¢ Once the desired dental occlusion is set on the models, the  amount of the skeletal movement required in the maxilla,  mandible or both will become evident. Subsequently, a  simulation of the actual orthognathic surgery is performed  on the mounted models as in conventional technique. This  will indicate the possible occlusal outcome of the stan-  dard approach.   e Intermediate and final splint can then be made on these  mounted models as they are set up into the planned skel-  etal movements.   e With the advent of virtual planning and three-dimen-  sional simulation softwares, the same set-up model sur-  gery can be performed by scanning the physical models  and bite registration details into the software, and the  three-dimensional intermediate and final splints can be  printed.    The surgical procedures in the maxilla, mandible or chin are  themselves performed using described standard techniques,  whether it is the conventional technique or the SFOA  technique.    Fig. 67.3 (a) Standard model mounting. (b) Before the procedure, the  teeth that have adapted to the skeletal discrepancy are simulated and  reorganized into their predicted location, similar to real pre-surgical    Fig. 67.4 Flow diagram showing various surgical procedures in  each of the jaws    orthodontic treatment. (c) Simulation of actual orthognathic surgery is  then performed. (d) Surgical splints fabricated to aid in real-time  surgery    Systematic review published by Peir6-Guijarro et al. [21] in  2006 reviewed 179 publications and finally selected 11 arti-  cles for final reporting. They found that the SFOA technique  was most commonly reported in Class II skeletal malocclu-  sion than in skeletal Class II malocclusion with prevalence of  about 84.7%. The single largest advantage described was  shortened treatment duration time owing to the RAP con-  cept, and the disadvantage was potential error in predicting  the post-operative occlusal outcome resulting in greater or  lesser surgical movements of the jaws.    The future of SFOA technique lies in using augmented  skull models, virtual orthodontic set-up to replace the  mounted study model set-up and the computer-aided  design and computer-aided manufacturing fabrication of  intraoperative splints (Fig. 67.5). The 3D virtual orth-  odontic set-up will help the orthodontist to predict the  eventual (at the end of orthodontic treatment) position and  the axial inclination of each tooth scrupulously. This is a  compelling step before the surgeon’s skeletal base correc-  tion simulation, since the patient’s prevailing occlusion    2. The facial profile is improved from the commencement of treatment as a result of skeletal base correction  3. Patient and orthodontist satisfaction rates are high. High patient satisfaction is associated with improved cooperation during post-operative    4. Orthodontic decompensation is efficient and effectual in response to the establishment of a proper maxillomandibular relationship and the regional    5. Surgical movements may not be curbed due to orthodontic constraints. There is more freedom to choose the surgical movement in accordance with    the clinical requirement for individual patients  6. Patient recovery takes place expeditiously    7. When sleep-disordered breathing is the main indication for treatment, early maxillomandibular advancement increases the dimensions of the upper    1. Case selection is critical because the baseline occlusion cannot guide treatment objectives. Therefore, high clinical expertise, meticulous prediction of  post-operative tooth movement and precise assessment of skeletal discrepancy are imperative    2. The bending procedure for a passive surgical wire is tedious and complex    3. Bonding and removal of the surgical wire are taxing; there is a relatively high bonding failure rate before and during surgery  4. The extent of surgical movements is necessarily greater, because surgical correction needs to make up for dental compensation    6. ost-surgical fluidity during bone healing could cause skeletal instability, and its impact on relapse has not yet been fully investigated  7. Orthodontic appointments should be scheduled more often than in a traditional approach. This could be stressful for the orthodontist  8. Constant correspondence between the surgeon and the orthodontist is indispensable    Fig.67.5 The workflow demonstrating the pre-surgical orthodontic movement set-up (a), the surgical procedure on the maxilla (b), the procedure  on the mandible (c), the post-operative ensuing dental occlusion with splint in situ (d, e) and the design of the final splint (f)    cannot serve as a guide for skeletal repositioning as it lies  in a compensated state.   Usability of temporary anchorage devices (TAD) and  interdental corticotomies is a factor which can add to the  future of SFOA. The TAD permits a wider range of orth-  odontic vectors and avoids premature bracket loading with  secondary troublesome dental extrusion. Interdental corti-  cotomies can augment the RAP and further enhance the orth-  odontic treatment duration.    Performing orthognathic surgery even before any orthodontic  tooth movement (SFOA) offers a unique advantage of address-  ing the patient’s chief complaint at the very beginning, thereby  improving the acceptance and compliance of the patient to  overall treatment. It also offers the big advantage of significant  decrease in total duration time by making use of the RAP. The  final outcomes, in the way of facial aesthetics, dental occlu-  sion and stability, are similar when using orthodontics-first  and surgery-first approaches. However, it must be remem-    bered that both the surgeon and the orthodontist must trend  with care as there is a premium on patient selection and both  should be involved as a team during every stage of the treat-  ment, starting from diagnosis to debonding. Surgeon-  orthodontist team should know the orthodontic principles and  understand the limits of orthodontic teeth movement and must  accommodate dental decompensation in their initial treatment  planning. The surgeon should be capable of carrying out des-  ignated osteotomy and intermaxillary fixation with occlusion  bite plate on misaligned dental arches and providing the stabil-  ity after skeletal reposition. The future of orthognathic surgery  is geared towards reducing the overall treatment duration  without compromising the final outcome.DisclosureAuthors  have no financial conflicts to disclose.    Fig. 67.6 Case Scenario 1. A 19-year-old male presenting with for-  wardly place upper front teeth. (a—c) Preoperative pics showing frontal,  profile and right lateral views. (d, e) Preoperative occlusion showing  end on molar relation and compensated dental occlusion with anterior  deep bite and excessive overjet. (f, g) Post-surgical orthodontic treat-    ment in progress. Excessive nature of curve of Spee can be noted, and  the change in overjet and overbite post-surgery can be appreciated. (h—  j) Post-treatment facial pics: frontal, smiling and lateral views. (k, 1)  Post-treatment intraoral pics. (m, n) Comparison of pre-operative and  post-operative lateral cephalograms    Fig.67.7 Case Scenario 2. A 26-year-old male presenting with promi-  nent lower facial appearance and mobile lower front teeth. (a, b)  Clinical pics showing lateral and frontal views: Concave facial profile  can be appreciated with acute nasolabial angle. (c) Lateral cephalogram  showing skeletal Class III jaw bases with normodivergence. (d, e)  Intraoral picture showing reverse overjet, Class HI molar relationship    and spacing in lower anteriors. (f, g) Post-surgical orthodontics in prog-  ress. Reversal of overjet can be noticed. (h—J) Post-treatment facial pics  in profile and frontal. (k) Intraoral post-treatment pic showing occlusal  relationship with normal overjet and Class I molar relationship. (1) Post-  operative cephalogram   References nathics: who does what, when? In: Proffit WR, White RP, Sarver  DM, editors. Contemporary treatment of dentofacial deformity. Ist  ed. St Louis, MO: Mosby; 2003. p. 245-67.   8. Kim JH, Mahdavie NN, Evans CA. Guidelines for “surgery first”  orthodontic treatment. In: Bourzgui F, editor. Orthodontics—  basic aspects and clinical considerations. Ist ed. Casablanca:  University Hassan II of Casablanca: IntechOpen; 2012.  p. 265-300.   9. Huang CS, Chen YR. Orthodontic principles and guidelines for the  surgery-first approach to orthognathic surgery. Int J Oral Maxillofac  Surg. 2015;44(12):1457-62.   10. Nagasaka H, Sugawara J, Kawamura H, Nanda R. “Surgery first”  skeletal class III correction using the skeletal anchorage system. J  Clin Orthod. 2009;43(2):97-105.   11. 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Jacobs JD, Sinclair PM. Principles of orthodontic mechanics in  orthognathic surgery cases. Am J Orthod. 1983;84(5):399-407.    Villegas C, Uribe F, Sugawara J, Nanda R. Expedited correction of  significant dentofacial asymmetry using a “surgery first” approach.  J Clin Orthod. 2010;44(2):97-103.   Assael LA. The biggest movement: orthognathic surgery  undergoes another paradigm shift. J Oral Maxillofac Surg.  2008;66(3):419-20.   Liou EJ, Chen PH, Wang YC, Yu CC, Huang CS, Chen  YR. Surgery-first accelerated orthognathic surgery: postopera-  tive rapid orthodontic tooth movement. J Oral Maxillofac Surg.  2011;69(3):781-S.   Liou EJ, Chen PH, Wang YC, Yu CC, Huang CS, Chen  YR. Surgery-first accelerated orthognathic surgery: orthodontic  guidelines and setup for model surgery. J Oral Maxillofac Surg.  2011;69(3):771-80.   Storey E. The nature of tooth movement. Am J Orthod.  1973;63(3):292-3 14.   Pellegrini GG, Gonzales CM, Somoza JC, Friedman SM, Zeni  SN. Correlation between salivary and serum markers of bone turn-  over in osteopenic rats. J Periodontol. 2008;79(1):158-65.   Binder T, Goodson J, Socransky S. Gingival fluid levels of acid and  alkaline phosphatase. J Periodontal Res. 1987;22(1):14-9.   Liao YF, Chiu YT, Huang CS, Ko EW, Chen YR. Presurgical ortho-  dontics versus no presurgical orthodontics: treatment outcome of  surgical-orthodontic correction for skeletal class III open bite. Plast  Reconstr Surg. 2010;126(6):2074-83.   Peiré-Guijarro MA, Guijarro-Martinez R, Hernandez-  Alfaro F. Surgery first in orthognathic surgery: a system-  atic review of the literature. Am J Orthod Dentofac Orthop.  2016;149(4):448-62.    Open Access This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.  org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropri-  ate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.    The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in    a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.   Proper balance and harmony between the different parts of  the face—forehead, eyebrows, eyes, nose, ears, cheeks, lips,  mouth, jaws, chin, etc.—are the main factors deciding aes-  thetics. Aesthetic evaluation is mandatory to understand the  problems systematically. During the primate evolution, jaws  lost many functions, and the size suffered a gradual reduc-  tion, which resulted in an orthomorphic face. The facial mus-  cles gained fine expression and smile, the exceptional  features of Homo sapiens.   Mandible forms the movable lower part of the head.  Mandible is attached to the upper part of the head by liga-  ments and musculature. It articulates with the glenoid fossa  of temporal bone through temporomandibular joint, a syno-  vial joint having translator and rotator movements (gingly-  moarthrodial). These movements facilitate chewing and  grinding functions. In our prehuman ancestors, the body of  the mandible was parallel. In humans, since the brain case  has expanded, the temporal bones were pushed apart, TMJ  followed suit giving the lower jaw a parabolic contour. The  Simian shelf reduced to genial tubercles to facilitate speech  and to compensate and strengthen the jaw and the chin devel-  oped in humans. Metaphorically it is often stated that “the  brain case has expanded at the expense of the jaws”.   In some people, surgical repositioning of the mandible  may be required to achieve an ideal facial form and restore  functions such as mastication and breathing.    Electronic Supplementary Material The online version of this chap-  ter (https://doi.org/10.1007/978-98 1-15-1346-6_68) contains supple-  mentary material, which is available to authorized users.    V. Mani (D+!)  Department of Oral and Maxillofacial Surgery, Mar Baselios  Dental College, Kothamangalam, Kerala, India    © The Association of Oral and Maxillofacial Surgeons of India 2021    Mandible is the sturdiest bone of the face with strong basal  bone and the alveolar part housing the dentition. The near  round protuberances seen bilaterally at the cephalic end of  the mandible are called condyles, and they form its articula-  tion with the TMJ. The mandibular condyles articulate with  the temporal bone and help in the rotatory and translatory  movements of the mandible as well as to transmit forces  from the mandible to the skull base. A good understanding of  the gross anatomy of the mandible is essential to understand  its surgical implications. This needs to include the TMJ, the  dentition, the supporting ligaments, and the muscles of mas-  tication (Fig. 68.2a, b) and facial expression.   On the medial aspect of the vertical ramus is the man-  dibular foramen just posterior to halfway between the  anterio-posterior width of the vertical ramus almost in line  with the most concave part of the anterior border of the  ramus. Just above is the lingula, a triangular prominence to  which the sphenomandibular ligament is attached.  Mandibular neurovascular bundle enters the mandibular  foramen on the lingual side of the mandible and runs below  the tooth roots in the body of the jaw, in the inferior alveo-  lar canal. It curves upward and backward by about 2 mm  and gives out the main branch, mental nerve, below the sec-  ond premolar area, and gives sensory supply to the lower  lip and chin [1].    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1-15-1346-6_68    Fig. 68.1 (a) Gross anatomy of mandible, (b) ligaments attached to mandible    Fig. 68.2 Muscles attached to mandible. (a) Buccal aspect and (b) lingual aspect. (GG) Genioglossus and (GH) Geniohyoid    Deformities of the jaws can be associated with the ties it will be appropriate to assess the relationship of the lower  dento-alveolar complex, the skeletal base or both. jaw to the rest of the face. Certain parameters are used to assess  the deformity objectively. Clinical evaluation is the most impor-   They may be either an excess or a deficiency. tant of them all. Face has to be assessed frontally and laterally.  Profile analysis of the face is the most important of them  These problems can occur in three different vectors: all—it could be convex, straight, or concave. Convexity can  Antero-posterior, Transverse and Vertical be due to protruded maxilla or retruded mandible/chin.    Concave face can be due to retruded maxilla or prognathic  mandible/chin (Fig. 68.3a, b, c).    Fig. 68.3 On profile analysis face can be convex (a), straight (b), or concave (c)    Subnasale perpendicular is another important tool for  assessing the profile. A line is drawn perpendicular to the  Frankfort horizontal plane through the point Subnasale. This  line is expected to go through the upper vermilion border,  2 mm anterior to the lower vermilion border and 4 mm ante-  rior to the soft tissue (Fig. 68.4) Pogonion. +/—2 mm is con-  sidered to be within normal limits. This is an important  assessment tool for understanding the sagittal relationship of  both the maxilla, mandible and dentition.   Likewise another perpendicular line is drawn from  Nasion. (N. Perpendicular). This line is ahead by  5.3 + 6.7 mm in males and 6.9 + 4.3 mm in females. This  indicates the position of mandible. Regarding the bony pogo-  nion this line is ahead by 4.3 + 8.5 mm in males and  6.5 + 5.1 mm in females. This indicates the position of the  chin. Angle SNB is 80 + 2 normally. Less indicates retruded  mandible and more indicates protrusion of mandible. All  these measurements are in relation to the cranial base, the  portion that is not changed in routine orthognathic surgery.  (Fig. 68.5) (Refer Chap. 66 for further details).    e Mandibular prognathism  (a) Skeletal  (b) Dento- alveolar  e Mandibular retrusion  (a) Skeletal  (b) Dento- alveolar  e Mandibular Transverse Deformity  (a) Broad  (b) Narrow  ¢ Chin Deformity-Excess  (a) Vertical  (b) Transverse  (c) Antero posterior  ¢ Chin deformity deficient  (a) Vertical  (b) Transverse  (c) Antero posterior  ¢ Deep bite deformity  ¢ Open bite deformity(Apertognathia)  e Asymmetry    Specific conditions like presence of deep bites and open  bites can occur with these clinical situations and may help us  understand the dentoalveolar compensations that occur with  them. Assessment of patients is done with facial analysis and  cephalometrics.    Common cause for mandibular excess is either developmen-  tal or genetic. Very large mandible may be associated with  acromegaly.   . Lower lip and chin are more anteriorly placed than  normal (SN perpendicular)    It is often due to genetical or developmental reasons.  Ankylosis of temporomandibular joint, trauma to mandibu-  lar condyle and aplasia of condyle can also cause deficiency  in mandibular growth.    Clinical features associated with mandibular defi-  ciency are the following:  1. Bird face appearance.  2. Severe over jet.  3. Class II relationship of dentition.  4. Crowding of lower anterior teeth.  5. Flaring compensation of lower anterior teeth.  6. Face appears small.  7. Lower third of the face is short.  8. Stomion-menton is proportionately short.  9. Labiomental fold is usually absent.  10. Chin neck angle is obtuse.  11. Angle SNB—less than 78°.  12. Angle FHP N P—less than 82°.   Vertical and anterio-posterior excess of chin are usually  associated with mandibular prognathism. Though in progna-  thic mandible, chin appears prominent, it need not be so in  objective analysis. Hence it is essential that the chin be  assessed independently in relation to the other structures. To  assess the vertical discrepancy, the best technique is to mea-  sure the length from stomion of the lower lip to the menton  and compare this to the length obtained from measuring the  subnasale to stomion of the upper lip, in rest position. The  former should be double the latter normally.   2. Unilateral cleft lip and palate, and other unilateral  clefting syndromes    Asymmetry could be pan facial or limited to certain areas.  Frontal analysis is the ideal method to assess asymmetries.  Drawing vertical and horizontal parallel lines on the face will  help to locate the area of asymmetry. This can also be done  using a grid. PA cephalogram and frontal photographs are  helpful in analyzing facial symmetry.   Orthognathic surgery to the mandible involves numerous pro-  cedures that facilitate the correction of deformities of the man-  dible and its dentoalveolar complex in all planes of space. This  encompasses a wide array of techniques which may be classified  based on the anatomical location they are applicable to.    1. Dentoalveolar complex  (a) Anterior subapical  (b) Total subapical  2. Midline symphyseal osteotomy  . Body osteotomy  4. Ramus Osteotomy  (a) Vertical sub-sigmoid osteotomy—intra- and  extraoral  (b) Sagittal split ramus osteotomy (BSSO)  5. Subcondylar osteotomy    The discussion of all the techniques is beyond the scope of  this chapter, and hence, detailed description of the vertical ramus  osteotomy, the sagittal split ramus osteotomy, and theUnterior  subapical osteotomy are provided here.    Movement of the mandible in the antero-posterior direction is  usually achieved by ramus osteotomy. Limberg in 1925  reported subcondylar oblique osteotomy [2]. Thomas,  Robinson, Shira, and others described buccal osteotomy which  involved the ramus. Later, Caldwell and Letterman (1954)  described vertical subcondylar osteotomy by extraoral  approach, which became very popular [3]. This technique min-  imized trauma of the inferior alveolar neurovascular bundle.   In 1927 Wassmund described the inverted “L” osteotomy.  Though the primary indication was mandibular prognathism,  many surgeons advocated vertical osteotomy and certain  modifications like inverted “L” osteotomy [4] and “C” oste-  otomy for advancement of the mandible [5]. Bone grafting  has to be done to fill the gap created (Fig. 68.6).   In 1937 Lane described a sagittal osteotomy. Obwegeser  modified the Lane’s technique in 1955, and the technique of  sagittal split osteotomy is credited to him. Sagittal split is a  versatile technique and has the following superiority over  others [6]. It gives great flexibility in repositioning the distal  tooth-bearing segment. There is better cancellous bone con-  tact, which enhances healing. The alterations in the position  of the condyles and muscles of mastication are minimal.  There is no extraoral scar. Injury to the marginal mandibular  nerve is avoided. However, chance of injury to the inferior  alveolar neurovascular bundle is high [7].   Dal Pont made the modification to sagittal split by a verti-  cal cut through the lateral cortex [8]. Hunsuck extended the  medial cut only to a point above the lingula. This minimized  trauma to overlying tissue [9].    This was one of the most popular procedures for correcting  mandibular prognathism. Rigid internal fixation techniques  and certain modifications like “C” osteotomy and inverted “L”  osteotomy have been used for advancement of the mandible.  After “C” or “L” osteotomy, the gap created while advancing  or rotating the distal segment is filled with bone graft [10].  The major disadvantages are the external scar and the  possible inadvertent damage to the marginal mandibular  nerve. With judicious care, these problems can be mini-  mized. Better visibility is the major advantage (Fig. 68.7).   Submandibular skin incision is placed, about 1.5 cm below  the angle of the mandible. The incision is taken down to the  platysma, which is then divided. Marginal mandibular nerve  lies below the platysma running parallel to and often below  the lower border of the mandible, crossing the facial vessels  superficially as it passes upward. Attempt should be made to  identify this structure and preserve it.   After identification and protection of the marginal mandibu-  lar nerve, dissection is carried down to the bone. The perios-  teum is incised over the angle. The periosteum is reflected  superiorly to the level of the sigmoid notch on the lateral aspect  of the ramus. Coronoid process may be cut in cases when more  than | cm of posterior movement is required (Fig. 68.8).   Lateral aspect of the ramus is inspected for a small bulge cor-  responding to the lingula. This helps to identify the mandibular  foramen. Osteotomy is performed posterior to the anti-mandibu-  lar foramen bulge so that the mandibular nerve is not injured.  (The position of the bulge is arbitrary and not definite.) A vertical  bony cut is made starting at the sigmoid notch and progressing to  the lower border near the angle of the mandible. Condylar seg-  ment is separated from the distal part of the mandible and is  detached from the medial pterygoid muscle. The condylar part is    Fig. 68.7 Subsigmoid vertical osteotomy was the most popular tech-  nique before the introduction of sagittal split osteotomy. This technique  is used for correcting mandibular prognathism    Fig. 68.8 When the push back required in subsigmoid vertical  osteotomy is more than | cm, sectioning of the coronoid process helps  in better stability    laterally placed on the distal segment. After packing the wound,  the same steps are followed on the contralateral side.   The mandible is repositioned into the desired position  with the help of the splint, and intermaxillary fixation is  done. The site of surgery is again approached. Some sur-  geons prefer to leave the condyle as such on the lateral aspect  without any transosseous wiring. There is no consensus  regarding the decortication of the opposing surfaces.   Removal of bone or decortication may be done if it helps  the condyle to achieve a proper position within the glenoid  fossa with minimal displacement. Decortication helps better  contact of the cancellous bone enhancing healing. Stabilization  of the fragments by transosseous wires or screws and plates  can be done. Rigid internal fixation eliminates intermaxillary  fixation. Except in rigid internal fixation, intermaxillary fixa-  tion for a period of 4-6 weeks is mandatory. After the fixation  is removed, elastics may be used to guide the movements.   Wound closure is done in layers. Skin may be closed by  monofilament 6-0 or smaller sutures. A pressure dressing is  applied for the first 24-48 h. Drain is usually not necessary  and, if done, has to be done through a separate stab incision  below the main incision. Sutures are removed after 5—7 days,  and the wound is supported by dressing for a period of  another | week, if required.   Complications are usually rare. Bleeding may occur due  to injury to the retromandibular vein or masseteric artery  where it crosses laterally through the sigmoid notch. Bleeding  can be controlled by routine methods like pressure packs,  ligation, etc. Injury to the marginal mandibular nerve is  another possibility. A transitory deficiency in the function of  the lower lip may be anticipated due to traction on the nerve.  This often recovers completely. In case of sectioning of the  nerve, micro-surgical repositioning is advised.   If care is taken in closure, and infection is avoided, scar  formation is minimal. If scar is formed, revision may be done  subsequently (Fig 68.9a—d).    Sagittal split osteotomy (SSO) can be employed for correct-  ing both retrognathism and prognathism. Modifications by  Dal Pont, Hunsuck, and Epker have made the procedure sim-  pler and more acceptable biologically. Schuchardt and Lane  described sagittal split osteotomy of the vertical ramus [11].  It was Obwegeser who popularized it. His medial cut was  above the mandibular foramen, and his lateral cut was below  that of Schuchardt’s and extended to a part just above the  angle, at least 25 mm below the lingual cortical cut.  Obwegeser and Trauner in 1955 described the bilateral sagit-  tal split osteotomy [6].   Dal Pont in 1961 made a major modification by extending  the cut anteriorly and making the vertical cut just below the  second molar [8]. Hunsuck in 1968 modified the cut in the  medial cortex of the vertical ramus, limiting the cut to just  behind the mandibular foramen. Postoperative complications  got reduced [9] (Fig. 68.10a, b).   Bell and Schendel and Epker extended the vertical cut on  the buccal side to the lower border of the mandible reducing  the incidence of wrong splits [12, 13]. A reciprocating oste-  otomy saw, which is specifically meant for the inferior bor-  der (right and left) may be used to perform inferior border  osteotomy [14].   Performing an inferior border osteotomy results in much  lower incidence of persisting inferior border defects. Hence,  during advancement of the mandible, it is advisable to exclude  the lingual cortex in the split. Piezosurgery has been compared  with conventional surgical drills/saws by several authors for  BSSO. They have reported substantially longer surgery time  for piezosurgery. Image-guided surgery has also become pop-  ular in the recent years, and this allows the surgeon to track the  position of the instruments and segments during the operation  in real time. Modern intraoperative navigation systems are  being used in orthognathic surgery also [15].   Incision is placed over the region of the ramus to the mid  ramus. It is carried over the external oblique ridge, extends  up to the first molar region, and curves down to the buccal  vestibule.   Initially only the mucosa is incised over the ramus region.  Retracting the tissue buccally, before incision, prevents the  exposure of the buccal pad of fat, a troublesome interference,  during surgery. Sharp dissection at the ramus is continued to  the periosteum, using scissors, knife, and periosteal  elevators.   Periosteal elevation of the lateral aspect of the mandible  at the molar region is performed down to the inferior border.  On the ramus, lateral dissection may be kept minimal but  enough to achieve proper visibility and access.   Medial dissection is done very carefully on the medial  side of the ramus. The level of the lingula and the entry of the  inferior alveolar nerve into mandibular foramen are visual-  ized. This is usually in level with the deepest concavity along    Fig. 68.9 Mandibular  prognathism corrected by  subsigmoid vertical  osteotomy of the ramus on  both sides to set back the  mandible. (a, b) Preop  pictures, (c, d) postop pictures    the anterior border of the coronoid and ramus. With a small  flexible Freer Elevator, the tissue is dissected taking care not  to perforate the periosteum on the medial aspect. Dissection  should be above the level of the mandibular foramen. Using  a bigger elevator, the medial aspect of the mandible above  the lingula is exposed subperiosteally. (Perforation of the  periosteum not only induces bleeding but may injure the  mandibular nerve.) Sigmoid notch is identified for better ori-  entation. Subperiosteal dissection should be minimal, but  enough to retract the tissues medially without much traction  on the mandibular neurovascular bundle [16].  B. Osteotomy (Videos 68.1 and 68.2):   Osteotomy is initiated by cutting the cortical bone above  the lingula on the medial side. This cut should extend behind    the mandibular foramen but need not be up to the posterior  border of the ramus (about half to two-thirds of the antero-  posterior dimension of the ramus). The cut is taken down-  ward along the external oblique ridge to the second or first  molar region. The depth of the cut should be minimal, just  enough to reach the cancellous bone (Figs. 68.11 and 68.12).   Conventionally the vertical cut is made at the second molar  region as the bone is thicker there. The CT analysis conducted  by Y Tsuji et al. on prognathic mandible demonstrated that  the mandibular thickness of the mandible increased along the  mandibular foramen toward the mandibular body. The man-  dibular canal was located relatively lingually at all sites. They  also observed that marrow space, located on the buccal side,  was thicker at the region of mandibular body [17].    Fig.68.10 Bilateral Sagittal Split Ramus Osteotomy (BSSO/BSSRO).  (a) Obwegeser split: Initially the medial cut in sagittal split osteotomy  extended up to the posterior border, and when the distal segment was  pushed back, the margin used to jut out, which had disadvantages like    Fig. 68.11 The medial cut is taken above and behind the mandibular  formen and deepened to the cancellous bone    relapse tendency and injury to the retromandibular tissues. (b) Hunsuck  split: At present the medial cut is taken above the mandibular foramen  much short of the posterior border but behind the foramen. The compli-  cations are much less (also see Fig. 65.12b)    Fig. 68.12 The cut is extended obliquely through the anterior border  of the mandible to the buccal plate and taken downward at the level of  the first or second molar region, up to the inferior border. Only the cor-  tex need be cut. Deeper cuts could injure the inferior alveolar nerve and  may cause wrong splits (also see Figs. 69.31 a—c and 70.24 c, d)    A study on cadaveric mandible by Promma et al. reported  that the thickness of buccal cortex to the mandibular canal is  about 6.5 and 5 mm at the second molar and first molar  regions, respectively [18].   Some surgeons prefer to take the cut more forward to the first  molar region. This gives better accessibility for intraoral plating.  When the vertical cut is made, it is mandatory to protect the soft  tissue over the inferior border by using a channel retractor. If the  vertical cut includes the inferior border, the direction of the split  is controlled. A rotary instrument or a reciprocating saw is used  for cutting. Once the cortical cut is completed, a small spatula  osteotome is malleted to the site beginning from the medial cut  to the vertical cut. Osteotome should be directed laterally just  beneath the cortical plate so that the neurovascular bundle is not  injured. Larger osteotomes are used, and slowly the fragments  are pried apart using a smith spreader (Fig. 68.13).   As the splitting takes place, the neurovascular bundle is  visualized, and care is taken to maintain it to the medial frag-  ment. If it is attached to the proximal segment, the NV bun-  dle is freed with a periosteal elevator. Next the fragments are  pried apart using the spreader. The procedure is repeated on  the opposite side.   Sagittal split osteotomy can be used for either mandibular  advancement or setting back. If mandibular advancement is  to be done, the medial pterygoid muscle is separated from  the inferior border of the distal segment with a periosteal  elevator. When the mandible is set back, medial pterygoid  and masseter may have to be stripped, if needed, to prevent  the displacement of the condylar segment posteriorly.  Posterior stripping of the pterygomasseteric sling in SSO  should be minimized to the antegonial notch. In excessive  stripping, possibility for avascular necrosis increases [19].    Fig. 68.13 A spreader is used to split the mandible at the ramus region    When the tooth bearing segment (distal segment) is  pushed back, the buccal plate of the condylar segment (prox-  imal segment) overlaps the distal. This overlapping part is  excised, and the proximal segment is allowed to rest on the  cancellous part without any tension (Fig. 68.14).   Pushing the mandible backward reduces the space in the  oral cavity. The tongue may not have enough space, and  sometimes this induces tongue thrusting, snoring, etc. Some  authors advocate reduction glossectomy to improve function  related to airway speech and mastication. They also opine  that reduction glossectomy improves aesthetics and controls  unfavorable mandibular growth [20].   Mommaerts reported that mandibular lengthening done  through endoscopic surgery, with transoral osteosynthesis,  reduced stripping of the periosteum and therefore conse-  quent edema [21]. In certain clinical situations Unilateral  sagittal osteotomy is performed. Refer case scenario in Fig.  69.31 (Maxillary orthognathic surgery Chap. 69) where an  unilateral sagittal osteotomy was combined with maxillary  osteotomy to correct canting of the maxilla.   Rigid internal fixation (RIF) using plates and screws or  lag screws is the preferred way of fixation. Prior to RIF, the  position of the jaw is adjusted, and intermaxillary fixation  is done with splint in position. Both fragments are allowed  to be in passive position before RIF is performed.  Intermaxillary fixation (IMF) is removed after rigid fixa-  tion. However, some surgeons prefer to keep the IMF for 1  week. For rigid fixation 2.5 mm four-hole mini plate with  gap is used for push back (Fig. 68.15). Longer plates are  used for advancement. Multiple lag screws can also be  used. Skeletal rigid fixation has been shown to reduce  relapse following mandibular advancement [22-24] (Figs.  68.16a, b, c, and 68.17a, b, c).    Fig. 68.14 Excess of the buccal plate is cut off when the intention is to  push the mandible backward    Rachmiel et al. in their study found improved stability  with four-hole plate and monocortical screws, with a relapse  rate of about 18% only [25].   Based on a 10-year experience of using bioresorbable  plates in orthognathic surgery, Laine P et al. opine that these  devices are safe to be used. Relapse rate with bioresorbable  screws is the same as with metal in SSO [26]. Another method  of fixation is wiring. If resorting to wiring, intermaxillary fixa-  tion has to be kept for 5-6 weeks. Maturation of soft and bony    Fig.68.15 Rigid fixation after sagittal split osteotomy of the mandible  using mini plate    tissues continues at the surgical site and approximates that of  non-surgical sites at 12 weeks postoperatively [27-29].   The inferior alveolar nerve is less likely to get damaged  when monocortical screws are used. These screws also allow  for readjustment if there is any inadvertent malposition dur-  ing surgery can be readjusted more easily [30]. An in vitro  study on sheep mandibles found that both mini plates and  bicortical screws resulted in a similar level of stability [31].  (Figs. 68.18a, b, c, d, 68.19a, b, c, and 68.20a, b, c).   Wounds are irrigated well and bleeding is controlled by  routine methods. If there is continued bleeding drain is indi-  cated. Wounds are closed by 3-0 Vicryl sutures.   Edema is expected after sagittal split osteotomy. It  resolves within 2 weeks. Edema at the angle is the last to  resolve. Suction drainage minimizes tissue edema following  mandibular surgeries. Betamethasone administration signifi-  cantly reduces postoperative edema. Widar H. et al. has also  observed less bleeding intraoperatively, but no difference in  neurosurgery disturbances [32].   Diminished sensation over the lip is experienced by most  of the patients and is mainly due to traction on the neurovas-  cular bundle. If there is no injury to the neurovascular bun-  dle, sensation returns within a few weeks. More than  two-thirds of the patients experience some sensory deficit  even after | year. However, most of the patients get adjusted  to this altered sensation and are satisfied with the overall  result. Limitation of movements of jaw in all direction after  osteotomy is often experienced. Sagittal split advancements  often cause significant limitation of range of motion [33].    Fig.68.16 Bilateral sagittal split osteotomy to set back the mandible, with rigid fixation. (a1, b1) Preoperative photographs. (a2, b2) Postoperative  photographs. (c1, c2) Pre and post operative lateral cephalograms with superimposed tracings   A systematic review of fracture patterns in sagittal split  was analyzed by Steenen and Becking and reported 2.3%  bad splits in sagittal splits. The most common was buccal  plate fracture of the proximal segment and lingual plate frac-  ture of the distal segment. Coronoid and condylar neck frac-  tures were seldom [35].   Wrong split usually occurs in cases where the last molar  is removed at the time of surgery. Hence it is advised to  have the third molar removed (if needed) about 6 months    Fig. 68.17 Case of mandibular prognathism with maxillary deficiency, managed by maxillary advancement and mandibular set back by BSSO.  (al, b1) Preop pictures. (a2, b2) Postop pictures. (c1) Preop cephalogram. (c2) Postop cephalogram    prior to the osteotomy. If the lingual cortical plate is bro-  ken, soft tissue separation from the lingual plate should be  kept to the minimum, so that the blood supply is not jeop-  ardized. Patients with a shorter ramus and buccolingually  thin mandible are more susceptible to wrong split during  SSO [36]. Advanced age can increase the risk of a bad  split. Use of a spreader helps to reduce the incidence of  wrong splits.   Care should be taken to maintain the continuity of the  neurovascular bundle. If it is transected, ideally the cut ends  are micro-anastomosed. However, in common practice,  where a micro-surgeon may be unavailable, it is advisable to  perform direct suturing to attain epineural approximation.  With a repositioned and repaired neurovascular bundle, the  sensation is recovered though the period it takes is longer.    Long-lasting neurosensory deficiency (NSD) was underesti-  mated by the surgeons as compared to the patient’s subjec-  tive symptoms. Long-lasting NSD was reported as 7.5%  (Questionnaire) and 3.8% (Record), after intraoral vertical  ramus osteotomy, and as 11.6% (Questionnaire) and 8.1%  (Record) after sagittal split osteotomy [37]. Vertical subsig-  moid osteotomy with rigid fixation may be considered as a  viable alternative if it is important to avoid alterations in sen-  sation, whereas BSSO maybe preferred if retromandibular  scar is of concern. Neurosensory disturbance, after SSO with  additional genioplasty, is more than after SSO alone [38].   Care should be taken while plating the segments. Improper  plating can pull or push the condyle to an untoward position.  Postoperative X-rays are taken to assess the situation. If  needed, the displacement has to be corrected by returning the  patient to surgery. Displacement of the condyle from the  fossa is one of the main reasons for relapse [24, 39]  (Fig. ).    Beukes J. et al. in 2016 studied condylar rotational toler-  ance in BSSO treatments and reported a range of 10°-15°  after orthognathic surgery.   Unilateral SSO is a safe procedure in lateral prognathism  of mandible due to unilateral condylar hyperplasia or trau-  matic malocclusions [40]. The condyle that was not operated  on, only rotated 3—4° within the glenoid cavity, and it was  established that this is within the range of functional articular  adaptation [41]. Mendez-Manjon R. et al. observed that  mandibular advancement by BSSO can positively displace  the condyle especially on the posterior aspect [42].   In their study Borstlap et al. observed that in sagittal split  advancement postoperatively, 8% of patients showed postop-  erative condylar resorption. Patients of relatively low age are  at risk of condylar alterations or resorption. Occurrence of  pain and TMJ sounds in the first few months postoperatively  are highly indicative of condylar changes to occur in the pre-  ceding months [43]. Predisposition in females for condylar  resorption after sagittal split osteotomy may be attributed to    Fig. 68.18 A case of left unilateral ankylosis of the TMJ resulting in _ sliding genioplasty. (a) Pre operative picture before ankylosis correc-  trismus and facial deformity. Treated by release of ankylosis by gap tion (b) frontal view with facial asymmetry (c) after release of ankylo-  arthroplasty, temporal myofacial flap interposing, and extended lateral __ sis, (d) after correcting facial asymmetry    the modulation of biologic response, by estrogen and prolac-  tin [44]. Mobarak compared the skeletal stability of postop-  erative changes in low angle and high angle Cl II patients  following mandibular advancement. High angle had more  horizontal skeletal relapse due to condylar movement in a  superior direction. Changes in intercondylar angle and width  after BSSO advancement or set back may influence TMJ  function [45-48].  4. Excessive Bleeding:   Bleeding can be from inferior alveolar neurovascular bun-  dle, medullary bed, and facial vessels or rarely from retro-  mandibular vein. Bleeding from the former two can be    controlled by local measures; but the facial vessels will have  to be clamped and tied, for which an extraoral incision may  be required. Using the channel retractor with a cup to hold  the inferior border and cutting with a Steiger-type carbide  bur (this has side cutting and rounded cutting end and cuts  bone with minimal injury to the soft tissue) prevents injury to  the facial vessels.   Injury to the retromandibular vein is very rare and is due  to inadvertent injury to the soft tissues behind the mandible.  Bleeding can be controlled by absorbable gelatin sponge.  Excessive oozing can cause significant edema, and if oozing  is present, a drain may be placed.    Fig.68.19 Facial asymmetry and vertical and sagittal excess of maxilla corrected by LeFort1, anterior maxillary osteotomy, bilateral sagittal split  osteotomy and advancement genioplasty. (al, b1) Preoperative pictures. (a2, b2) Postoperative pictures. (c1) Preoperative lateral cephalogram.    It was Caldwell and Letterman who developed the intraoral  vertical ramus osteotomy in 1954 [3]. Later in 1964, this was  described by Moose [49] and Winstanley in 1968 [50], and  modifications have been suggested by many others. Intraoral  approaches medially and laterally to ramus were described  [49, 50]. Herbert and associates in 1970 described the use of  special oscillating saw and popularized the intraoral tech-  nique to reach the ramus (Fig. 68.22).   The procedure overcomes the disadvantages of extraoral  vertical ramus osteotomy. The advantages are the follow-  ing: (1) external scar is avoided and (2) there is no injury to  the marginal mandibular nerve. The advantages over sagit-  tal split osteotomy are that injury to the mandibular neuro-  vascular bundle is avoided. The main disadvantage is the  difficulty in access and visualization of the area. However,  there is a delay in healing and possibility of projection of  antegonial notch [51]. Mandibular nerve hypoesthesia can  be expected to improve faster in young patients than the  older ones. So [VRO may be a better option for elder  patients [52].   A mucosal incision is made along the anterior border of the  mandibular ramus. This is extended to the coronoid process  and extended laterally up to the first molar area and subperi-  osteally dissected to expose the sigmoid notch, inferior bor-  der, and the posterior border of the ramus. Two fibro-optic lit  Bauer retractors (left and right) are used—one on the sig-  moid notch and the other at the angle area to get excellent  exposure of the ramus. An oscillating saw angled at 105° is  used to do the osteotomy. The cut is made posterior to the  ante lingula prominence and directed superiorly to the sig-  moid notch and inferiorly to the mandibular angle.   If circummandibular wiring fixation is planned, the  medial aspect of the ramus above the lingula is dissected  subperiosteally to the posterior border. The width need only  be enough to pass the wires.   Osteotomy, as in the extraoral approach, extends from the  sigmoid notch to the inferior border behind the entry of the  mandibular nerve. The intraoral vertical cut should be made  no more than 5—7 mm anterior into the posterior border. This  will be behind the mandibular foramen [53]. According to  some, ante lingual prominence as a landmark is unpredict-  able [54].    Fig.68.20 Case of open bite managed by BSSO. (al, b1) Preoperative pictures. (a2, b2) Postoperative pictures. (cl) Preoperative lateral cepha-  logram. (c2) Postoperative lateral cephalogram    Fig. 68.21 Displacement of the condyle due to torquing as demon-  strated here in a vertical ramus osteotomy, is the most common reason  for TMJ problems    For better access, as well as visibility and mobility of the  fragments, the coronoid process can be separated using a  reciprocating saw. The coronoid process is allowed to retract  with the temporal muscle.   An appropriate retractor with a cup at the end can be held  hooked to the posterior border, and the soft tissue is held  retracted laterally. Care should be taken to orient the cut and  also to prevent injury to the soft tissues.   After the osteotomy, the condylar segment is overlapped  laterally over the mandible. Medial pterygoid attached to the  medial aspect may be stripped in the anterior region of the  segment to facilitate tension-free positioning of the condylar  segment. The same osteotomy is performed on the opposite  side, and intermaxillary fixation is maintained for 6 weeks.  Extraoral approach for vertical subsigmoid osteotomy is  advocated for large mandibular set back of greater than  10 mm [55, 56].   Over correcting the mandibular set back by 2 mm to pro-  vide compensation for relapse is also recommended [57].  The use of skeletal wire fixation seems to stabilize the initial  movement, but does not influence long-term relapse [58].   Ghali and Sikes have reported that IVRO improves  TMJ functions and relieves TMJ symptoms more effec-  tively when compared with SSRO, due to the final posi-  tion of the condyle more anteriorly and inferiorly which    results in an increased joint space and better disk-condyle  relationship [59].   Ratil Gonzadlez-Garcfa described endoscopically assisted  intraoral vertical ramus (IVRO) and subcondylar (ISCO)  osteotomies for the treatment of symmetric mandibular  prognathism. He claimed the use of saw and bone chisel  under the continuous control of the endoscope provides a  safer approach since the osteotomy is controlled during the  whole process and provides complete visualization of the  osteotomy site [60].    Stabilization, Fixation, and Wound Closure  Most surgeons use circummandibular or transosseous wires.  Rigid internal fixation using plates is rather difficult to place  and carries greater risk of injury to the mandibular nerve.  Lag screws or mini plates are sometimes used.  Intermaxillary fixation for a period of 6 weeks is advised,  if rigid fixation is not used. Wound closure is done as in sag-  ittal split, adhering to the basic principles.    TMJ Considerations  Radiographically there is an anterior downward and forward  movement of the condyle after ramus osteotomy. However,    there is a tendency to return to its preoperative position [61-  63]. Double contouring of the condyle after 6 months was  reported which is attributed to condylar remodeling [64].  Remodeling of the glenoid fossa also has been documented  [65]. Complications and their management are very much  similar to those of sagittal split.    This was one of the earlier procedures used for mandibular  prognathism. Blair reported a body osteotomy at the premo-  lar level for mandibular prognathism in 1906 [19]. Since the  advent of the ramus procedures, body osteotomy has lost its  popularity. However, in certain conditions, body osteotomy  may have to be resorted to.   Depending on the site of osteotomy, soft tissue dissection  varies. The basic principle is to reflect the buccal mucoperi-  osteum down to the inferior border taking care not to injure  the mental nerve, but at the same time, exposing it.   The next step is to remove the buccal cortical plate from  the mental foramen region backward to behind the osteot-  omy/ostectomy site for release of the neurovascular bundle.  The tooth at the osteotomy site is extracted.   Using a fissure bur, the outer cortical plate is marked and  a window is cut. Using curettes and chisels, the cancellous  bone around the neurovascular bundle is removed. The nerve  is released using a nerve hook. Anterior continuation of the  inferior alveolar nerve (the incisal branch) is severed. This  helps in better retraction of the nerve. Continuation of the  mental nerve is preserved. Mucoperiosteum on the lingual  aspect is elevated and protected by a periosteal elevator.  Osteotomy is completed adhering to the basic principles.  The same procedure is repeated on the contralateral side.  Body osteotomy at the molar level is almost outdated since  the advent of sagittal split osteotomy.   Body osteotomy anterior to the mental foramen can be  resorted to in certain specific cases. The main indication of  this procedure is lower dentoalveolar protrusion with ante-  rior open bite. “V” osteotomy is done at the first premolar  region. This will not reduce the total mandibular length but  rotates the anterior segment upward and_ backward.  Maintenance of the arch and occlusion is important. Rigid  fixation is mandatory as tendency for relapse is very high due  to the pull exerted by the genioglossus and geniohyoid mus-  cles (Fig. 68.23).   Stabilization is achieved by arch bars or by orthodontic  means. Fixation using two plates (each plate having a mini-  mum of 4 holes) on each side is advised.    Fig. 68.23 Body osteotomy at the level of the premolar region.  Diagrammatic representation    Midline osteotomy is used either to narrow or to expand the  mandible. Expansion is more difficult than narrowing, due to  tissue resistance. Before narrowing the mandible, a space  must be created at the symphysis by extracting an anterior  tooth (Fig. 68.24). Parasymphyseal step osteotomy approach  with a hybrid mode of force application might be the most  viable option for true mandibular arch expansion.    Hullihen performed the first ever anterior subapical osteot-  omy and published it in 1849 [66]. This procedure was done  for a girl who had sustained burns and had the anterior seg-  ment of the mandible got distracted anteriorly by the traction  of the scar resulting in everted lip, protrusion of teeth, and  open bite.   Hofer used anterior subapical osteotomy to advance ante-  rior teeth for correction of mandibular dentoalveolar retru-  sion [67]. Kole used this technique to correct an anterior  open bite.   1. To retrude the lower anterior dentoalveolar seg-  ment; often used in conjunction with subapical  osteotomy in bimaxillary protrusion   Sulcus incision is made and the mucoperiosteal flap is  reflected. Subperiosteal tunneling is done at the lingual  aspect of the planned osteotomy site. Extraction of tooth  (usually the first premolar) is done, if the intention is to  retrude the dentoalveolar segment (Figs. 68.25a, b, c  and 68.26a, b, c).   Osteotomy or ostectomy is done as planned. Stabilization  and fixation are done in the preplanned position using  prefabricated occlusal wafer splint or arch wires. Stabilization  is done by using lag screws, position screws, or wires. Semi  rigid bone plates are considered superior.   In cases where the anterior segment of the mandible is  repositioned superiorly, a gap is created at the osteotomy site  (subapically). Autogenous bone grafting is advised to fill this  gap.   When the osteotomy is planned behind the mental fora-  men, the neurovascular bundle may be released from the  mandibular canal and protected.    Mcintosh in 1974 described total mandibular alveolar oste-  otomy. In 1942 Hofer [67] described horizontal osteotomy of  mandible for horizontal deficiency or excess and  asymmetry.    Fig. 68.25 Lower anterior subapical osteotomy. (a) Diagrammatic representation. (b) Photograph demonstrating the vertical interdental and the  horizontal connecting osteotomies. (c) Lower subapical osteotomy can also be combined with genioplasty    Total subapical osteotomy of the mandible is used Surgery (Fig. 68.27a, b, c)    mailly for the following indications: Mucoperiosteal flap is reflected. The neurovascular bundle is  1. For repositioning the entire dentoalveolar segment. released as described earlier (under “Body Osteotomy of  2. When the mandibular length and chin position are Mandible’). Osteotomy is started behind the most posterior  compatible with the maxilla and its position, but the teeth. The cut is made using reciprocating saw or bur. Care  deformity is mainly in the dentoalveolar part. should be taken not to damage the lingual tissues. Osteotomy   vascular bundle. About 4 mm of bone should be left below   Adequate bone should be present below the apices of the _ the apices of the teeth to ensure proper blood supply. The  roots. dentoalveolar segment is freed and mobilized. Preplanned    g » Protrusion anterior dentoalveolar segment of mandible treated by lower anterior subapical osteotomy. (al, b1) Preoperative pictures.  (a2, b2) Postoperative pictures. (cl) Preoperative lateral cephalogram. (c2) Postoperative lateral cephalogram    occlusion is established. Maxillomandibular fixation is aided  by wafer splint. The neurovascular bundle is repositioned  and secured in position using struts of bone [68].   Stabilization is done using rigid internal fixation.  Postoperative sequelae are usually marked by edema which  gets resolved in about 2 weeks. Sensory disturbances, though  present, usually recover with time. Injury to the neurovascu-  lar bundle may cause permanent anesthesia.   Complications are usually rare. The importance of proper  blood supply through the lingual pedicle is of utmost  importance. This is mainly through the mylohyoid, genio-  glossus, and geniohyoid muscle attachments.    The basic plan of the surgery is not very different from that  of total subapical osteotomy. The incision is limited to the  posterior area. The decompression of the neurovascular bun-  dle is done, and the osteotomy is performed as described  earlier.   The main indications are to shift the dentoalveolar seg-  ment in question to the required direction in all three  dimensions of space, i.e., antero-posterior, vertical, or  horizontal.    Genioplasty is used for the correction of deformities of the  chin. It is possible to reposition the chin in all the three  dimensions of space. Hofer in 1942 introduced horizontal  osteotomy of the symphysis [67]. By repositioning the infe-  rior mandibular symphysis, a more stable and natural appear-  ance can be attained [69].   Incision is made on the labial mucosa on the lower lip. It is  extended from the premolar region to the opposite symmetri-  cal site. The incision is taken to the periosteum, which is  reflected to expose the bone. Subperiosteal dissection is done  to expose the inferior border of the mandible. Mental nerve  is identified and protected.   Bony cut is made on the chin about 4.5 mm below the apices  of the teeth. The posterior end of the cut should taper to the  inferior border, behind and below the mental foramen. (This  prevents step defects at the site which may be manifested in  the soft tissue also.) The segmented portion is freed from the  rest of the mandible but remains pedicled to the digastric and  geniohyoid. If the inferior segment is stripped off the perios-  teum, making it a free graft, intense inflammatory reaction    Fig. 68.27 Total subapical osteotomy. (a) Neurovascular bundle is released. (b) Osteotomy is done using bur or saw. (c) The dentoalveolar seg-    and necrosis may occur [70, 71]. The degree of bone resorp-  tion and necrosis is indirectly proportional to the amount of  pedicle attached to the segment [72].   For vertical reduction, another horizontal cut is made  below the original cut, and the measured segment of bone  between the two cuts is removed. It is not advisable to cut off    the bone from the inferior border as this can imperil the nor-  mal contour of the chin. Unilateral vertical reduction/aug-  mentation can be done for correction of asymmetry, since the  chin can be moved in all three dimensions (Fig. 68.3 1a, b).  Increase in the height of the chin can be achieved by bone  grafting (preferably autogenous) and rigid internal fixation    using plates. Unilateral height increase can be done in asym-  metry. However, high morbidity is associated with bone graft  and alloplastic materials, such as recurrence, infection, and  resorption [73]. Chin can be augmented (augmentation geni-  oplasty) (Fig. 68.30a—c) by bringing the cut inferior segment  anteriorly and fixing it by rigid fixation. For major advance-  ment, stepwise augmentation, slicing the inferior border into  more than one horizontal segment is advocated (Figs. 68.32  and 68.33a, b, c) (Also refer Fig. 78.42).   Retropositioning of the chin can also be done, but the soft  tissue adaptation following posterior positioning of the chin is    not 100%. While positioning the inferior border posteriorly,  the labiomental fold may get compromised (Fig. 68.34a, b).   Genioplasty can be used for widening and narrowing the  chin in the horizontal direction. In mild mandibular asym-  metry, the midpoint of the chin may be off the facial midline.  By horizontal repositioning of the inferior border, the mid-  point of the chin can be brought to the midline of the face,  and the mandibular asymmetry can be camouflaged  (Fig. 68.35).   Following surgery, the wound is closed adhering to the  basic principles. Like in other osteotomies, 3—6 months are  necessary for the lip to adapt to the new position and resume  normal function. Complications are rare with this procedure.  Wound dehiscence occurs in some cases. Meticulous irriga-  tion and aseptic measures can reduce the chances of infec-  tion. Sensory loss for a period may be noticed due to traction  on the mental nerve. Often sensation is regained within 3-6  months. Rigid fixation technique has reduced the chances  shifting of position of the moved segment. Though the  reported relapse rates vary in genioplasty, most authors agree  that relapse occurs within the first year [38, 70].    Mandibular basal osteotomy is an innovative predictable  technique for correction of deficiency, excess, and/or asym-  metry of the inferior mandibular border, decreasing morbid-  ity, and many other complications of traditional bone grafts  and alloplastic techniques [74].    Fig. 68.29 (a) Osteotomized chin can be moved in all the three dimensions. (b) Advancement genioplasty    Fig. 68.30 Case of augmentation genioplasty.  (al, bl) Preoperative pictures. (a2, b2)  Postoperative pictures. (c1) Preop lateral cepha-  logram. (¢2) Post op lateral cephalogram    Fig. 68.31 Mild facial asymmetry can be corrected by bone grafting on one side, after osteotomy. (a) Pre-operative assessment and (b) treatment    Fig. 68.32 Major advancement of the chin can be effected by a double  sliding genioplasty, which is a step osteotomy of the lower border    In extended genioplasty dissection and exposure of the  chin, mental nerve and body of the mandible is recom-  mended by a degloving incision. With complete dissection  and mobilization of nerves, an extended osteotomy to the  antegonial angle may be carried out (Fig. 68.36a, b). The  basal osteotomy below the inferior alveolar canal ensures  proper proportionality between the advanced segment and  the posterior mandible [75]. By laterally sliding the lower  border (extended lateral sliding genioplasty), facial asymme-  try can be corrected. This procedure can be used for minimal  to moderate hemifacial microsomia and facial deformity    resulting from unilateral ankylosis of the temporomandibu-  lar joint [76] (Fig. 68.37a, b).    Distraction osteogenesis is a recent introduction into the  field of orthognathic surgery. This technique has revolution-  ized the possibilities of orthognathic surgery. It was Ilizarov,  a Russian orthopedic surgeon, who popularized this tech-  nique. The first team to report gradual distraction of human  mandible was McCarthy et al. in 1992 [77]. As bone has got  regenerative capabilities, it is possible to create new bone  and lengthen the bone in a cut segment by slowly distracting  it. The technique is very useful in the management of defi-  ciency of bone in the maxillofacial region as this is an excel-  lent method to increase bone quantity. The spectrum of  indications for distraction is widening and innovations are  coming up in the field rapidly. During distraction certain  important principles are to be followed.   It is advisable to complete the osteotomy and mobilize the  segment as far as possible and then put back the segment to  its original position and distract it gradually. During distrac-  tion directional stability should be ensured, in order to coun-  teract the pull of the soft tissue and the muscles [78]. A new  terminology “distraction histogenesis” has come into vogue  as not only the bone but the surrounding tissues also get  lengthened. Geniohyoid muscle can be lengthened to a maxi-  mum of 20% of its resting length [79]. It is possible to dis-  tract the inferior alveolar nerve as well [80]. It is important  that the distracted tissue is attached to vital tissue to maintain    Fig. 68.33 Case of retruded chin corrected by double sliding advancement genioplasty. (a1, b1) Preoperative pictures. (a2, b2) Postoperative  pictures. (c1) Preoperative lateral cephalogram. (c2) Postoperative lateral cephalogram    perfusion. Periosteum is rich in osteogenitor cells, and for  callus distraction and bone lengthening, the periosteum  should be intact, and hence it should be preserved [48].  After osteotomy a latency period of 4—7 days is advised to  provide time for the soft tissue to heal. However other factors  like age, stability of fixation, type of operative procedure that  affects the formation process during the initial stages of distrac-  tion, etc. are to be considered before deciding on the latency    period [81]. Certain other studies did not show any difference  between no latency period and a latency period [82, 83].   Four stages are recognized in distraction osteogenesis—  (a) fibrovascular hematoma formation, (b) formation of col-  lagen fibers parallel to distraction vector, (c) bone formation  and remodeling of new bone, and (d) formation of solid com-  pact bone. In fast distraction collagen, fibers may lose con-  tact, and bone formation may not take place. In slow    Fig. 68.34 Reduction of the chin can also be achieved. However, sharp margins are to be trimmed off. (a) Pre-operative planning and (b) treat-  ment (osteotomy design)    distraction, consolidation of bone may occur earlier [84].  Karp et al. demonstrated that intramembranous ossification  is what occurs predominantly [85]. Distraction of 1 mm per  day is the widely accepted rate [86]. Direct current electrical  stimulation may be useful in activation and consolidation    period [87-89]. Insufficient distraction and defective vectors  can compromise the final result. These complications can be,  to some extent, managed by manipulating the regenerate  bone by the application of orthodontic traction [79, 90-92].  OW and Cheung reported a lower incidence of persistent  IAN disturbance (3%) after MDO compared with BSSO, of  which the incidence was 28% [93]. In terms of skeletal sta-  bility in small to moderate advancements, there is no signifi-  cant difference between BSSO and DO. DO requires a  second surgery for removal of the distractor, which goes in  favor of BSSO [94].   Distraction osteogenesis has got an important role in  managing sleep apnea, in cases like micrognathia, Pierre  Robin syndrome, hemifacial microsomia, Treacher Collins  syndrome, etc. [4, 95]. Due to its complex nature, it is rather  difficult to treat unilateral craniofacial microsomia, in grow-  ing children. Maxilla, zygoma, mandible, external and mid-  dle ear, facial and trigeminal nerves, muscles of mastication,  and overlying soft tissues are the structures of the first and  second arch which are involved [96] (Refer Chap. 78 on  Hemifacial microsomia and Treacher Collins syndrome).   In severe cases, in neonatals, tracheostomy may become  necessary. Mandibular distraction is an effective method in  resolving upper airway obstruction and decannulation of trache-  ostomy [97-99]. Rachmiel A. et al. have reported an increase of  mandibular volume by 28.4%, increase of upper airway volume    Fig. 68.36 After making a degloving incision an extended genioplasty may be done. it is possible to preserve the mental nerve. (a) Oblique view    Fig.68.37 Major asymmetry of the mandible can be corrected to a great extent by extended lateral sliding genioplasty. (a) Pre-operative plan and    by 71.92%, and increase in oxygen saturation. This study was  conducted in children between 13 months and 7 years of age  [25] (refer Chap. 87 on distraction osteogenesis).   In severely hypoplastic mandible multi-stage correction  starting from young age may be considered for functional  and psychological reasons. Less severe cases may be taken  up for single stage correction after the permanent dentition is  erupted [100].    Mandible is a horse shoe-shaped bone hinged to the skull  and performs the major function, chewing, and forms the  lower part of the mouth which houses the tongue and other  musculature. All the muscles of mastication and many other  muscles of facial expression are attached to the mandible.  Hence mandible is an important structure in both function  and aesthetics. Different osteotomies of mandible can move  the jaw in almost all the three directions and change the size  and shape of the jaw and face to achieve better function and  aesthetics. This chapter is intended to elucidate various oste-  otomy techniques on the mandible.    Patient aged 22 years, female, reported with complaint of  facial deformity with a history of fall when she was about 8    years old. No deformity was noticed, and no treatment was  taken at that time, and as she grew up, she started developing  deviation of the face.   On examination she had facial asymmetry with deviation  of the jaw to left side. She had class II occlusion and defi-  cient chin. Radiographs revealed under developed and  deformed condyle on the left side. The mandible was shifted  to the left side due to underdevelopment of the mandible on  left side (Fig. 68.38a1, bl, cl).   Treatment: Pre-surgical orthodontic treatment with sagit-  tal split osteotomy and extended lateral sliding genioplasty  with rib bone grafting on right side.    Patient aged 19 years reported with complaint of protruded  teeth and facial deviation with no relevant history.   On examination, she had vertical maxillary excess with  mandibular prognathism. Other clinical findings included  incompetent lips, convex facial profile, acute nasolabial  angle, and facial asymmetry with deviation of chin toward  right side. Radiographs revealed vertical and anterio-  posterior maxillary excess with mandibular prognathism and  deficient chin.   Surgery: LeFort 1, anterior maxillary osteotomy, bilateral  sagittal split osteotomy, and genioplasty were done for the  patient under general anesthesia.    Fig. 68.38 Mandibular asymmetry corrected by extended lateral sliding genioplasty. (a1) pre operative frontal view. (a2) post operative frontal  view. (b1, b2) pre and post operative Frontal cephalogram. (c1, ¢2) pre and post operative lateral cephalogram    of the facial nerve: an anatomical study. Indian J Plast Surg.  2010;43(1):60-4.    osteotomy of the ascending rami of the mandible. Dent Cosmos.  1925;67:1191-7.    retrognathia by vertical L osteotomy: a new technique. J Oral  Surg. 1968;26:259-64.    progenieund anderen unterkieferanomalien [The surgical cor-  rection of mandibular prognathism and retrognathia with  consideration of genioplasty]. Dtsch Zahn Mund Kieferheilk.  1955;23(1):1-26.    tion of mandibular prognathism. J Oral Surg. 1968;26:250-3.  Reitzik M, Barer PG, Wainwright WM, Lim B. The surgical treat-  ment of skeletal anterior open-bite deformities with rigid inter-  nal fixation in the mandible. Am J Orthod Denthofac Orthop.  1990;97(1):52-7.   Hensel GC. The surgical correction of mandibular protection,  retraction, and fractures of the ascending rami. Int J Orthodont  Oral Surg. 1937;23:184.   Bell WH, Schendel SA. Biological basis for the modification of  the sagittal ramus split operation. J Oral Surg. 1977;35:362-9.  Epker BN, Wolford LM, Fish LC. Mandibular deficiency syn-  drome: surgical considerations for mandibular advancement. 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Open Access _ This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.  org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropri-  ate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.   The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in  a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.    Maxillary Osteotomies  One does not know a science completely without knowing its  history.   The development of modern maxillary orthognathic surgical  procedures had diverse historical origins and contributions.  The removal of nasal and nasopharyngeal polyps via hemi  maxillary osteotomy was being undertaken in Europe in the  mid-nineteenth century, notably by the German surgeon  Bernhard Rudolf Konrad von Langenbeck (1810-1887) in  Berlin [2]. The first maxillary procedure that would today be  described as a total Le Fort I-type osteotomy appears to have  been undertaken in 1868 by the American surgeon, David  Williams Cheever (1831-1915) in Boston City Hospital to  provide surgical access for removal of a large nasopharyn-  geal polyp [3]. One year prior to this, in 1867, Cheever had  undertaken a down-fracture of the right hemimaxilla for  similar surgical access in another patient, who had made a  complete recovery [4]. The total down-fracture of the max-  illa at the Le Fort I level performed in 1868, described as  Cheever’s “double operation,” though technically successful,  had an unfortunate postoperative outcome in that the patient    Electronic Supplementary Material The online version of this chap-  ter (https://doi.org/10.1007/978-98 1-15-1346-6_69) contains supple-  mentary material, which is available to authorized users.    A. Dabir (4)  D. Y. Patil University School of Dentistry, Nerul, Navi Mumbai,  India    J. Vahanwala (5<))  Department of Oral Surgery, Vaidik Dental College and Research  Centre, Nani Daman, Daman, India    © The Association of Oral and Maxillofacial Surgeons of India 2021    subsequently died 5 days later, though probably not as a  direct result of the maxillary procedure [5, 6].   In 1901, a French surgeon from Lille named René Le Fort  (1869-1951) conducted experiments using blunt trauma to  intact cadaveric faces, from different directions and varying  magnitudes, and thereby described the natural planes of  maxillary and facial fractures [7, 8] now known as the Le  Fort classification of facial fractures. The names of the Le  Fort I-, II-, and III-type osteotomies are due to their similar-  ity to the Le Fort fractures.   In 1927, Wassmund carried out a maxillary osteotomy at the  Le Fort I level, without pterygoid plate disjunction or mobiliza-  tion at the time of surgery [9]. He used elastics to close an ante-  rior open bite, without placing a bone graft, which subsequently  relapsed. In 1934, Axhausen in Berlin described advancement  of the maxilla at the Le Fort I level, which was incompletely  mobilized, again with postoperative elastic traction [10].   Wassmund was the first to apply osteotomies at the Le Fort I  level for correction of midfacial deformities [11]. The technique  was subsequently modified by several surgeons including  Axhausen [12], Schuchardt [13], and Willmar [14]. In 1965,  Obwegeser improved the precision of the Le Fort I osteotomy by  suggesting complete mobilization of the maxilla so that reposi-  tioning was achieved without tension [15, 16]. The operation was  slow to gain popularity until 1973, till Bell’s description of the  remarkably resilient maxillary blood supply [17]. With advance-  ment in technique and the introduction of safe hypotensive anes-  thesia, the Le Fort I osteotomy has been increasingly utilized  over the last four decades. Over the years, various modifications  of the osteotomies, ORIF methods and bone grafting to the  mobilized maxilla, have continued to evolve and progress.    tions: frontal, zygomatic, palatine, and the alveolar process.  The maxilla forms the inferior and medial borders of the    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1-15-1346-6_69    orbits. The infraorbital foramen is located at an average dis-  tance of 7.8 mm, positioned inferiorly to the infraorbital rim  in women and 8.5 mm in men [18]. The vascular and sensory  supplies to the cheek, lateral aspect of the nose, and upper lip  exit the bone from this foramen.   The anterior alveolar processes surround the piriform aper-  tures and join to form the anterior nasal spine in the midline.  The anterior nasal spine is the most anterior inferior attach-  ment for the cartilaginous nasal septum, which extends poste-  riorly along the nasal crest and articulates with the vomer.   The maxillary sinuses are housed in body of maxilla.  Anteriorly, palatine process of each maxilla and posteriorly,  horizontal lamina of palatine bone form the hard palate. The  greater palatine foramen is located on each side approxi-  mately 10 mm posteromedial to the second molar.   The nasolacrimal duct travels within the bony wall  between the nasal cavity and the maxillary sinus before ter-  minating below the inferior turbinate. It can be injured dur-  ing the Le Fort I osteotomy or during an inferior turbinectomy  performed to allow superior repositioning of the maxilla  (Fig. 69.1) [19, 20].   Posterolaterally, the maxilla articulates with the pyrami-  dal processes of the palatine bones and the pterygoid plates  of the sphenoid bone. This pterygomaxillary junction extends  superiorly as a fissure, which ends at the pterygopalatine  fossa. The terminal portion of the internal maxillary artery  traverses the pterygopalatine fossa and gives off several  branches that can be encountered during a Le Fort I osteot-  omy (Fig. 69.2a, b). The average distance between the infe-    Fig. 69.1 Relationship of the nasolacrimal duct to the Le Fort I oste-  otomy cut. The meatus of the nasolacrimal duct is unlikely to be injured  if the osteotomy is made just beneath the infraorbital foramen and into  the piriform rim at the level of the inferior turbinate (IT). MT middle  turbinate    Fig. 69.2 (a) Branches of external carotid artery, (b) terminal branches of internal maxillary artery    69 Orthognathic Surgery for the Maxilla-LeFort | and Anterior Maxillary Osteotomy    rior extent of the pterygomaxillary junction and the posterior  superior alveolar artery is 15 mm, the infraorbital artery is  32 mm, and the descending palatine artery is 25 mm. The  descending palatine arteries travel through the perpendicular  plate of the palatine bones and are located approximately  34 mm posterior to the piriform rims and within 10 mm  medial to the pterygomaxillary fissures [21].   Osteotomies of the lateral nasal walls and at the pterygo-  maxillary fissures must be completed carefully to avoid  injuring these vessels. The internal maxillary artery is  23-25 mm above the base of the junction of the maxilla  with the pterygoid plates, with an average diameter of  2.5 mm. In addition to the direct vascular supply of the  maxilla by the descending palatine arteries, there is a rich  collateral vascular network from the soft palate supplied by  the ascending pharyngeal arteries and the ascending pala-  tine branches of the facial arteries (Fig. 69.3). The risk of  damaging the artery can be minimized by ensuring the pter-  ygoid osteotome is directed downward toward the palate  and is less than 1.5 cm above the inferior part of the fissure  [22, 23):   Bell’s work revealed that ligation of the bilateral descending  palatine arteries does not compromise the vascularity of the  maxilla as long as the soft palate pedicle is preserved [24, 25].   The pterygoid plexus of veins is located between the tem-  poralis and lateral pterygoid muscles and between the medial  and lateral pterygoid muscles. It receives tributaries corre-  sponding to the branches of the maxillary artery and drains    Fig.69.3 The vascular  supply of the osteotomised  LeFort I segment. The  ascending pharyngeal arteries  and the ascending palatine  branches of the facial artery    into the maxillary vein. Venous bleeding from this plexus  may be encountered during the posterolateral maxillary dis-  section and pterygomaxillary disjunction.   The risk of damaging the artery can be minimized by  ensuring the pterygoid osteotome is directed downwards  towards the palate and is less than 1.5 cm above the inferior  part of the fissure [22, 23].   Bell’s work revealed that ligation of the bilateral descending  palatine arteries does not compromise the vascularity of the  maxilla as long as the soft palate pedicle is preserved [24, 25].   S. Bruneder et al. studied a special type of arterial varia-  tion of the Le Fort I segment’s blood supply. Individuals with  this special arterial anatomy may clinically be at high risk for  hypoperfusion and avascular segment necrosis after surgery.  Individualized operation planning that takes the patient’s  arterial anatomy into consideration may help to prevent isch-  emic vascular complications of the Le Fort I segment and  improve operative outcomes in at-risk patients [26].   S. Salmanet et al. studied Dynamic analysis of maxillary  perfusion during Le Fort I osteotomy using indocyanine  green and concluded that there was a statistically signifi-  cant decrease in perfusion, as assessed by intraoperative  dynamic angiography, to the anterior maxilla following  maxillary down-fracture. Patient age, conventional versus  segmental Le Fort I osteotomy, changes in mean arterial  pressure and/or heart rate, and preservation of the descend-  ing palatine vessels had no statistically significant effect on  perfusion [27].    The patient’s sex and aspects of the skeletal and craniofa-  cial pattern have an influence on the pterygomaxillary area  and descending palatine canal anatomy. A preoperative com-  puted tomography analysis involving this evaluation could  reduce the risk of surgical complications. A preoperative CT  analysis should be performed on an individual basis and  should identify the differences between the two sides in the  same patient to allow a safer surgical procedure during Le  Fort I osteotomy [28].    The first anterior segmental maxillary osteotomy (ASMO)  was reported at the beginning of the twentieth century by  Giinther Cohn-Stock [29], wherein he tried to surgically  “correct a marked overjet and overbite of the central maxil-  lary teeth.” In his pioneering article in 1921, he described the  evolution of his idea to perform an osteotomy of the anterior  segment of the maxilla while preserving the vestibular pedi-  cle and, in a later design, also the palatal artery [29].   After Cohn-Stock’s original report, three variations of the  procedure were developed by Wassmund [9], Wunderer [30],  and Cupar [31]. These variations were designed to maintain  sufficient blood supply to the maxilla while giving adequate  access for instrumentation [32, 33].   In 1927 Wassmund [9] improved Cohn-Stock’s design by  creating a direct approach to the labial premaxillary cortex  using three vertical incisions and subperiosteal tunnelling for  completion of the labial osteotomy without reflection of  labial or palatal flaps. Both the labial and palatal blood sup-  ply are maintained; however, the osteotomy is made in a rela-  tively blind fashion. This method may be indicated for  closure of multiple interdental spaces [33] and for anteropos-  terior repositioning of the premaxilla [34]. It was found to  maintain the best vascularity of the repositioned segment in  comparison to all other ASMO methods [35].   In 1954 Cupar [31] described a different approach for  down-fracture of the anterior maxilla: exposure of the labial  aspect of the maxillary bone by a vestibular circumferential  cut and labial flap to facilitate the labial osteotomy under  direct vision. A palatal osteotomy was performed through a  tunnel, maintaining the palatal blood supply. This technique  is indicated for superior repositioning of the anterior maxilla  in cases of vertical maxillary excess.   In 1963 Wunderer [30] advocated reflection of a palatal  flap without fracturing of the anterior maxilla and mainte-  nance of the labial blood supply. Direct access for the palatal  osteotomy is the main advantage of this technique, especially  if posterior segments of the premaxilla must be removed.    Therefore, this technique may be indicated for setback of  the anterior part of the maxilla. Blood flow studies have dem-  onstrated that the transpalatal approach causes the greatest  decrease in blood supply to the anterior maxilla [36].  However, transpalatal soft tissue incision and labial osteoto-  mies impair vascular supply to the anterior maxilla from the  greater palatine vessels and the superior alveolar vessels,  respectively, leaving the labial collaterals as the sole blood  supply to the anterior maxilla [37].   In 1977 Epker modified the Cupar technique for down-  fracture of the anterior maxilla. He used only labial flaps and  vertical tunnels labial to the teeth to be extracted, which were  usually premolars on both sides [38]. Epker’s modification  enables repositioning of the anterior maxilla superiorly, pos-  teriorly, and inferiorly. The main advantages of the Epker  modification include preservation of the palatal pedicle, ease  of placement of internal fixation, provide access to the nasal  septal structures to prevent buckling of the nasal septum with  superior repositioning of the maxilla, and a direct approach  for removal of palatal bone. When required, bone grafting  for stabilization of an inferiorly positioned anterior maxilla  may also be done using this method.   The segmental Le Fort I osteotomy should not be excluded  from the technical armamentarium in orthognathic surgery.  On the contrary, the literature consulted suggests it to be a  useful tool for the three-dimensional surgical correction of  maxillary malposition [39].    Anaesthetic and Positioning Considerations: Controlled  hypotensive anesthesia has been shown to reduce bleeding  from mucosal and bone edges that contain a rich network of  small vessels, which cannot easily be identified and con-  trolled with surgical techniques. In healthy patients, a reduc-  tion in mean arterial pressure (MAP) of 30% below the  patient’s baseline with a minimum MAP of 50 mmHg is safe  [40]. In bimaxillary surgery, postoperative blood transfu-  sions are necessary in 13-48% of patients who do not have  controlled hypotension during the operation [41, 42]. The  need for transfusion has been nearly eliminated by using this  technique. Placement of an indwelling bladder catheter for  intraoperative monitoring of urine output as a marker of  renal perfusion should be considered when using controlled  hypotension. After induction of general anesthesia, the  patient is nasally intubated. Because intraoperative maxillo-  mandibular fixation is essential to establish the postoperative  position of the anterior maxilla, oral intubation is less desir-  able and should be avoided. The endotracheal tube must be  sufficiently below the level of the vocal cords to prevent    69 Orthognathic Surgery for the Maxilla-LeFort | and Anterior Maxillary Osteotomy    unintended dislodgement during premaxillary manipulation.  A shoulder roll is inserted to extend the neck without creat-  ing hyperextension. A sterile preparation and draping is per-  formed, leaving the orbits and nasion exposed. After the  planned mucosal incision is marked, local anaesthetic with  vasoconstrictor (lidocaine with 1:100,000 epinephrine) is  infiltrated in the labial sulcus. Palatal injection should be  avoided so as not to induce vasoconstriction in the palatal  pedicle.    A horizontal buccal sulcus incision is made by diathermy or  a #15 scalpel blade in one strike to the bone in the deepest  section of the buccal vestibule, circumferentially from right  to left second premolar. Next, the periosteum is reflected  superiorly to expose the entire canine fossa and piriform  aperture bilaterally. Inferiorly, minimum mucoperiosteal  stripping should be done, to maximize blood supply to the  osteotomized maxilla. The alveolar mucoperiosteum should  be undermined to the crestal bone only at preplanned oste-  otomy or ostectomy sites. The nasal mucoperiosteum should  be carefully separated from the nasal cavity floor to prevent  intraoperative bleeding, postoperative oronasal communica-  tion, and fistula formation. The cartilaginous nasal septum is  separated from the nasal groove of the maxilla to facilitate its  manipulation later.    As per surgical plan, maxillary premolars are extracted on  each side. Then, a reciprocating saw or piezo-surgical saw is  used to perform horizontal osteotomies. These bone cuts  should run posteriorly from each side of the piriform rim,  including the lateral maxillary walls and the lateral nasal  cavity walls. The nasal mucosa is protected with a curved  periosteal elevator. Due care should be taken to avoid injury  to the infraorbital nerve during retraction of the upper muco-  periosteal flap. The posterior limit for these osteotomies is  the planned vertical osteotomy/ostectomy, usually the first or  second premolar (Fig. 69.4a—d).   Figure 69.4b and Fig. 69.5 indicates the horizontal and  vertical osteotomies/ostectomies that are performed using a  #701 bur, mini-saw, or piezo. Precise bone removal should  be done to ensure an accurate postoperative position and suf-  ficient intersegmental bony contacts.   Meticulous tissue handling is of paramount importance at  this stage. Failure to preserve buccal mucosa may lead to an  impaired blood supply to the down-fractured maxilla or    establishment of an oroantral fistula, in addition to periodon-  tal compromise of the adjacent teeth.    After completion of the planned osteotomies and ostecto-  mies under direct visualization, the final osteotomy is done  using an osteotome. Neither a palatal incision nor a mucosal  undermining is done at this stage. A palpating finger is posi-  tioned on the palatal mucosa, and the transpalatal osteotomy  is completed with an osteotome. Down-fracture of the pre-  maxilla is accomplished with a bone hook. Additional  transpalatal and nasal ostectomies may be necessary at this  stage and should be finalized under direct access gained to  the nasal aspect of the down-fractured premaxilla. Careful  separation of the mucoperiosteum from the posterior seg-  ment of the palate facilitates setback of the anterior segment  and prevents it from becoming detached from the anterior  segment, compromising the blood supply (Fig. 69.6a, b).    If indicated for transverse widening or narrowing of the pre-  maxilla or closure of a diastema, a midpalatal osteotomy is  performed with an osteotome or piezo-surgical saw  (Fig. 69.7a, b).    After completion of the ostectomies, maxillary teeth are  placed into a preformed acrylic occlusal wafer, which is  wired to the maxillary dentition. Temporary maxillomandib-  ular fixation then is done, and a standard 1.5 or 2.0 maxillary  plating system is used at the maxillary buttresses to fixate the  bone segments in their planned postoperative position  (Fig. 69.8a—c).    After thorough irrigation of the surgical site with saline, the  mucosal incisions are closed with 3-0/4-0 vicryl suture. If  indicated, alar cinch and V-Y closure of the buccal incision  are performed at this stage. Maxillomandibular fixation is  removed at the end of the procedure. The maxillary surgical  wafer may be kept in place for 6 weeks for additional stabil-  ity of the maxillary segments and occlusal guidance  (Fig. 69.9a, b).    Fig. 69.4 (a—d) Epker’s modificaiton of Cupar’s down-fracture ante-  rior maxillary osteotomy. (a) Anterior maxillary excess with first pre-  molar to be extracted, not bonded othodontically, (b) vestibular incision  (5 mm superior to mucogingival junction). Osteotomy marked, which  includes a horizontal cut beginning at the pyriform rim, going lateral    above the apices of the anterior teeth and vertical cuts to complete the  bone removal at the site of the extraacted premolar, (c, d) Osteotomy  marking with autoclaved pencil and cuts for anterior maxillary segmen-  tal osteotomy. (see Fig. 69.10a2 for clinical profile view)    69 Orthognathic Surgery for the Maxilla-LeFort | and Anterior Maxillary Osteotomy    There are many acceptable modifications to the Le Fort I  osteotomy, and the sequence of steps may vary from surgeon  to surgeon. Figures 69.10a, b and 69.11a, b demonstrate a  patient who has undergone a Lefort | with anterior maxillary  osteotomy and mandibular subapical osteotomy for address-  ing her Vertical Maxillary Excess and dento-alveolar protru-  sion. The following is a description of the authors’ preferred  approach.    Fig. 69.5 Horizontal and Vertical Osteotomy Cuts (5 mm superior to  mucogingival junction) Osteotomy marked, Horizontal cut 5 mm above  the canine root tip, Vertical osteotomy marked approximate mesiodistal  width of premolar   Anaesthetic and positioning considerations must be followed  as previously discussed in the anterior segmental maxillary  osteotomy technique.    An external reference marker is placed at the nasion to facili-  tate proper positioning of the maxilla in the vertical plane  (Fig. 69.12a). Common techniques include insertion of a  Kirschner wire or a bone fixation screw. Less invasive meth-  ods include marking with a skin scribe, a suture or tape, but  these may be less reproducible due to skin mobility at the  site. Occasionally a soft tissue landmark such as the medial  canthus can also be used as a guide to measure from the inci-  sal edge of the anterior teeth (Fig. 69.12b)   External reference points have been shown to be superior  to internal references (lines or burr holes placed on the max-  illa above and below the osteotomy), which are prone to  inaccuracy due to the complex three-dimensional movement  of the maxilla [43, 44]. Preoperative measurements are then  obtained from the reference site to reproducible midline and  lateral maxillary landmarks, typically the maxillary dental  midline and the bilateral canine cusp tips or orthodontic  brackets.    and buccally from the pterygoid plate region, forward to the  midline bilaterally. A full-thickness mucosal and periosteal    Fig. 69.6 (a, b) Final palatal bone cut with osteotome, palatal mucosa protected with non-dominant hand for tactile sensation    Fig. 69.7 (a) Down-fracture anterior segment of maxilla and maintaining palatal mucosa. (b) Midline or paramidline osteotomy for horizontal  movement    Fig. 69.8 (a—c) Maxillary plating system used at the maxillary buttresses and pyriform region to fixate the bone segments in their planned post-  operative position in case of Le Fort I with AMO, (b) right side (c) left side    69 Orthognathic Surgery for the Maxilla-LeFort | and Anterior Maxillary Osteotomy 1521    Fig. 69.9 (a, b) (a) Alar cinch placement to control alar base, (b) V-Y closure of mucosa to maintain upper lip length    Fig. 69.10 (a, b) (al, a2, a3) Pre-surgical images of the patient. (b1, b2, b3) Post Le Fort I and anterior maxillary osteotomy images of the patient    Fig.69.11 (a, b) Intra oral photos of the same patient as in Fig. 69.10. (a1, a2, a3) Pre-surgical images of the occlusion. (b1, b2, b3) Post anterior  maxillary osteotomy images of the occlusion. A mandibular sub-apical osteotomy was also done for this patient (b2, b3)    incision is made in the soft tissue extending from the buttress  of the zygoma on the either side, 3-4 m above the mucogin-  gival junction with attention in the midline to a V-shaped  incision to allow for aesthetic closure [45, 46] (Fig. 69.13).  The incision can be made with a scalpel or electrocautery  Colorado needle. While layered incisions serve no advantage  for the dissection, electrocautery seems to control some  hemorrhage at the time of the incision.    Retraction is maintained with down-turned Obwegeser  retractors, and the superior mucoperiosteal flap is elevated  with a #9 Molt periosteal elevator. The anterior nasal spine,  piriform rim, infraorbital foramen, lateral maxillary wall,  and zygomaticomaxillary junction are exposed. Exposure of  the posterior maxillary wall and pterygomaxillary junction is  next performed with a Molt periosteal elevator, placed paral-  lel to the maxillary teeth and advanced posteriorly below    69 Orthognathic Surgery for the Maxilla-LeFort | and Anterior Maxillary Osteotomy    Fig. 69.12 (a, b) (a) External reference marker (skeletal landmark). A  stable extraoral reference point is established with a 0.035-inch K-wire  placed in the nasion. A caliper is used to measure the vertical distance  from the K-wire to the brackets of the central incisor teeth, and these    Fig. 69.13 Maintain a small inverted “V” shape over the midline fre-  num, with the lateral extension of the incision being Smm above the  muco-gingival junction, from first molar one side to the other    periosteum until the pterygomaxillary junction is encoun-  tered. The periosteal elevator on the bone and in a subperios-  teal plane is maintained with angulation as it proceeds  posteriorly to incline inferiorly or toward the hamular pro-  cess of the sphenoid bone. This alleviates the potential prob-  lem of entering the pterygomaxillary fissure and concomitant  increased hemorrhage [23, 47].   The nasal/septal mucosal dissection is performed after the  bilateral maxillary osteotomies have been completed and  involves elevation of the nasal mucosa with a curved freer  elevator to the posterior palatine bone (Fig. 69.14).    measurements are recorded. (b) A extraoral reference point at medial  canthal (soft tissue landmark). A caliper is used to measure the vertical  distance from medial canthal to the brackets of the central incisor teeth    Fig. 69.14 Exposure of the maxilla is achieved with a full horizontal  vestibular incision superior to the mucogingival junction. With appro-  priate retraction, the infraorbital nerves, piriform rims, posterior max-  illa, and anterior nasal spine will be identified    As may be preferred by some surgeons, reference marks  are placed vertically in the lateral wall of the maxilla, or  bone reference holes are placed a standardized distance  apart (15 mm seems to be a reasonable distance) vertically  in the buttress and in the pyriform rim region (Fig. 69.15)  [48-50].    Alternatively, a non-threaded Kirschner wire or Steinmann  pin is placed in the nasal dorsum, and a reference measure-  ment is taken from that Kirschner wire to the anterior denti-  tion to allow for determination of the amount of superior  repositioning of the anterior maxilla [51, 52].   With the use of a Tessier caliper, the vertical distance  (height) between the medial canthus and the mid-maxillary  incisor crown is measured on the left and right sides and  recorded; this generally measures between 55 and 70 mm    Fig. 69.15 Marking of osteotomy cuts, horizontal cut minimum of  5 mm above the apices of the teeth, step or sloping downward and back-  ward toward to maxillary pterygoid plates or Le Fort I level with step-  ladder cut    (Fig. 69.12). This is a reproducible relative measure of the  anterior vertical maxillary height [53].   A 701 straight fissure bur or reciprocating saw creates the  lateral maxillary osteotomy from the lateral nasal rim to the  zygomaticomaxillary junction. The osteotomy starts 3-4 m  above the nasal floor and is carried to the depth of the maxil-  lary sinus, back to the pterygomaxillary junction, approxi-  mately 30-35 mm above the bracket on the first molar tooth.  Cuts are made at least 5 mm above the roots of the teeth and  can be made higher as needed. A vertical step at the first  molar is carried inferiorly for 5-10 mm (step osteotomy per-  mits grafting in the zygomaticomaxillary buttress area sub-  sequently, if required) [54], and then it is continued in a  horizontal plane to the posterior maxilla ending in front of  the pterygomaxillary junction (Fig. 69.16a, b).   A 6- to 8-mm-wide, curved osteotome is placed in the ptery-  gomaxillary junction, with the leading edge angled inferior,  medial, and anterior. It is positioned in the junction with the  horizontal osteotomy centered over the middle of the  osteotome.   A finger can be placed palatally at the junction of the  hamulus with the tuberosity, and the mallet is used to  drive the chisel through the junction. The end of the osteo-  tome should be palpated on the palatal side as it comes  through the junction, but it should not penetrate through    Fig. 69.16 (a, b) (a) The lateral maxillary wall osteotomy is carried posteriorly from the piriform rim to the pterygomaxillary junction, (b) with  a vertical step ladder cut in the first molar region. The osteotomy is placed at least 5 mm superior to the root apices    69 Orthognathic Surgery for the Maxilla-LeFort | and Anterior Maxillary Osteotomy    Fig.69.17 A curved osteotome is placed in the pterygomaxillary junc-  tion, with the superior edge of the osteotome just above the horizontal  osteotomy. A finger is placed on the palatal side of the junction, and the  osteotome is gently tapped through the junction until palpated on the  palatal side, without perforating the soft tissue    the palatal tissue. There should be minimal resistance to  separation, and if significant resistance is encountered,  the osteotome position should be evaluated and reposi-  tioned (Fig. 69.17).   The scientific literature cites examples of damage to  the cranial nerves during the Le Fort I osteotomy  [55-58].   A small safe-sided osteotome initiates the lateral nasal  osteotomy at the piriform rim in the anterior extension of  the lateral maxillary osteotomy. A mallet drives the osteo-  tome posterior, parallel to the nasal floor, below the infe-  rior turbinate. One must take care not to go beyond 25 and  30 mm in depth during osteotomy. The lateral nasal wall  diverges (widens) posteriorly, and the osteotome must fol-  low that divergence. Minimal resistance will be encoun-  tered until the pyramidal process of the palatine bone is  encountered. At this resistance point, the osteotome can be  driven another few millimeters to influence the fracture  plane through this structure during down-fracture  (Fig. 69.18). The nasal septum osteotomy is next per-  formed with a guarded U-shaped osteotome. The osteo-  tome is introduced at the top of the nasal spine and is  driven inferiorly and posteriorly along the nasal floor to  separate the maxilla and palatine bone from the septum  (Fig. 69.19).    Fig. 69.18 The lateral nasal wall osteotomy is completed from the  inferior piriform rim to the anterior portion of the pyramidal process of  the palatine bone. Care is taken to avoid a complete osteotomy through  the pyramidal process in order to prevent injury to the greater palatine  artery and nerve. The right maxilla has been removed to show the  desired cross-section clearly    Fig. 69.19 The septal osteotomy is completed from the anterior nasal  spine through the vomer bone posteriorly, with the guarded prongs on  the septal osteotome angled inferiorly. Care is taken to retract the nasal  mucosa to minimize injury and bleeding to the soft tissue. The right  maxilla has been removed to show the desired cross-section clearly    Once the osteotomy cuts have been completed, some mobil-  ity should be readily evident, and down-fracturing be easily    Fig. 69.20 (a, b) (a) Once the maxilla is mobilized, the nasal mucosa  can be completely freed from the maxilla in the piriform rim region, (b)  The greater palatine nerve and artery can be visualized and protected    done with either bilateral manual digital pressure in the  canine fossa or with instrumentation support at the piriform  rim. Slowly separate the maxilla by pulling the anterior por-  tion inferiorly while observing the nasal mucosa to avoid  tears. If significant resistance is encountered, revise the oste-  otomy cuts thoroughly to ensure complete separation. To  avoid complications related to pterygomaxillary disjunction,  we prefer to extract maxillary third molar and make a verti-  cal osteotomy cut through the socket connecting the horizon-  tal cut on the posterolateral surface of maxilla.   Precious et al. (1991) did a study of 138 consecutive Le  Fort I osteotomies with successful down-fracture of the max-  illa by digital pressure alone (with no serious complications  except transient epistaxis that responded to local packing)  [59, 60].   Once the down-fracture is completed, place a Seldin ele-  vator or tongue depressor behind the tuberosity, and pull the  posterior maxilla forward. This will fully mobilize the max-  illa from its attachments. For large advancements, freeing the  tissue from the nasal side of the posterior maxilla in the soft  palate area will provide significantly more forward mobility.  In addition, in repeat maxillary surgery, mobilizing the max-  illa will most likely be more difficult, and time must be spent  freeing hard and soft tissue attachments to ensure passive  movements and surgical stability.    Removal of posterior interferences should be done immedi-  ately after down-fracture which will make it easier to set the  maxillary position later. The maxillary bony septum is  reduced most easily with a bur. The lateral nasal wall can be    during posterior bone removal from the lateral nasal wall area (yellow  arrows) (also see Fig. 65.12a)    reduced with a rongeur, bur, or reciprocating saw. While pro-  tecting the descending palatine nerve and artery with a curved  freer (Fig. 69.20a, b), the pyramidal process of palatine bone  is most safely reduced with the reciprocating saw or bone file.  Sometimes a thin spatula osteotome can be used. Finally, the  posterior tuberosity, anterior pterygoid plate, and posterior  lateral maxillary wall can be reduced with a bur or reciprocat-  ing saw (Fig. 69.21). If the superior movement of the maxil-  lary is more that 6 or 7 mm, a partial inferior turbinectomy  may be indicated to allow a passive impaction. The nasal  mucosa is incised with a scalpel blade along its inferior sur-  face in an anterior-posterior direction. The inferior half of the  turbinate is grasped with a large curved hemostat, and a dean  scissor is used to excise this portion. Complete removal of the  inferior turbinate is rarely necessary and can result in unpleas-  ant clinical side effects. Electrocautery is used to coagulate  the incised edge of the turbinate to minimize bleeding. The  nasal mucosa is then sutured with a running 4-0 vicry] suture.    A prepared surgical guide is necessary to ensure accurate  positioning of the maxilla. The guide is generally ligated to  the upper teeth with 26-28 gauge wire. The upper and lower  teeth are then wired together with 26-28 gauge wire, elas-  tics, or power chain (Fig. 69.22).    With the maxilla now fixed to the mandible, it is rotated into  position by applying posterior and superior pressure on the    69 Orthognathic Surgery for the Maxilla-LeFort | and Anterior Maxillary Osteotomy    Fig. 69.21 Posterior interferences are initially removed from the pos-  terior septum, lateral nasal walls, pyramidal processes of the palatine  bones, and lateral maxillary walls. This allows for passive seating of the  maxilla without posterior pivoting    mandible. To properly rotate the mandible, the surgeon places  two fingers at the gonial notch regions of the mandible and the  thumb of the same hand at the chin. Upward pressure is exerted  with the two fingers at the gonial notches, and the thumb exerts  a posterior and downward pressure. This “triangular” finger  formation ensures full seating of the condyles during mandi-  ble rotation and maxillary positioning. The surgeon then  rotates the mandible and maxilla upward, keeping pressure on  the two fingers and thumb (Fig. 69.38a—c). Upward rotation is    Fig. 69.23 The maxilla is rotated into place and anterior interferences  are removed to ensure full seating of the condyles at the desired vertical  position. Seating of the condyles of the mandible is achieved with supe-  rior pressure at the gonial notches and posterior pressure at the chin.  Once the correct vertical maxillary positioning is achieved, the  mandibular-maxillary complex can be reproducibly rotated with the  condyles in the fossa without any bone or soft tissue pre maturities  (Also see Fig. 69.12a, b)    stopped as soon as the first contact is detected, and this inter-  ference is reduced accordingly. Anterior interferences can be  easily reduced with a bur. The caliper is used to check the  vertical distance from the anterior brackets to the K-wire and  interferences are reduced accordingly. Closely observe the  nasal septum for early inferences and deviation. When all the  bony interferences have been completely removed, utilizing  the “triangular” finger formation, the mandible and maxilla  can be easily rotated up into a stable reproducible position,  with the condyles fully seated (Fig. 69.23).    With the maxilla positioned, four miniplates are accurately  bent to passively fit across the osteotomy in the piriform and  anterior buttress areas of the maxilla. Typically, there are two  fixation holes above and below the osteotomy in each bone  plate, for placement of four screws. Thin bone or large bone  gaps may require more fixation screws in each plate or even  require additional plates. Bone grafts can be adapted into the    Fig. 69.24 (a, b) (a) Rigid fixation with four plates provides vertical  and horizontal stability to the maxilla. The nasal septum should be free  of deviation, and the occlusion should be reproducible once interdental  fixation is released. Bone plates are used to stabilize the osteotomy  bilaterally at the nasomaxillary and zygomaticomaxillary buttress    osteotomy gaps, and press-fit into position, or rigidly fixed if  necessary [61]. Once the fixation has been competed, final  measurements with calipers are made to confirm proper ver-  tical placement (Fig. 69.24a, b).    69.4.10 Checks to Be Made Before Plate  Fixation of the Maxilla   2. Check that the teeth are occluding into the splint cor-  rectly (particularly posteriorly, ensure the tongue is  out of the way) and the condyles are seated correctly.   groove into anterior nasal spine). Ensure that tears  in the nasal mucosa if any are sutured.    Once the maxillary fixation is completed, the intermax-  illary fixation is released. The mandible is hinged with the  condyles fully seated using the “triangular” finger forma-  tion. Retractors should be used to hold the cheeks away  from the posterior teeth, and the mandible is rotated upward  such that the teeth fit into the maxillary splint. The tongue    areas. (b) Autogenous bone grafts have been adapted and fixated in the  osseous gaps to optimize bone healing and minimize postsurgical  relapse. Grafting may be indicated in complex movements, especially  large advancements and down grafting cases (yellow arrow)    is also manipulated out of the way if it is interfering with  closure. There should be a smooth closure into the splint  without any shifting or deviation of the occlusion. Contact  should occur simultaneously in the anterior and posterior  areas.   With the dissection and exposure of the paranasal muscu-  lature during Le Fort I osteotomy, the nasal cinch suture  provides appropriate repositioning of the soft tissue to  minimize postoperative nasal base widening. A slowly  resorbing suture (e.g., 2-0 polyglycolic acid) is placed  from an intraoral approach into the alar base bilaterally,  pulling the alar bases toward each other when tightened  (Fig. 69.25a, b). If properly done, tightening should result  in an equal or shorter alar base width when compared to  the preoperative width. This will frequently result in an  immediate upturned appearance of the nose, a protruded  positioning of the upper lip, and edema. These immediate  changes are transient and will disappear within a few  weeks. Following healing, the procedure results in mini-  mal widening of alar base from the preoperative measure-  ment (Fig. 69.26a, b).    69.4.11.2 V-Y Closure [63]  Typical movements of the maxilla and normal healing of  the circumvestibular incision can result in lip shortening,    69 Orthognathic Surgery for the Maxilla-LeFort | and Anterior Maxillary Osteotomy    Fig. 69.25 (a, b) Analar base cinch suture controls the alar base width  and counteracts postsurgical widening of the alar base. Care is taken to  correctly place the suture in the fibro adipose tissue and transverse nasa-    lis muscle at the lateral nasal base, allowing medial positioning of the  alar base during suture tying (yellow arrow)    Fig. 69.26 (a, b) Measuring the alar base pre-surgically (a) and post-surgically (after edema subsides and soft-tissue settles) (b) and confirming    lip thinning, and decreased vermillion show. The Le fort I  incision transects various components of the midface mus-  culature, including the transverse part of the nasalis mus-  cle, the myrtiformis muscle), and the levator anguli oris  muscle.   It is important to correctly suture the deep muscular lay-  ers in proper anatomic orientation, so that the facial contour  may be maintained [64].   The V-Y closure is performed to combat these undesir-  able changes. With the use of a skin hook, the tissue of the  midline vestibular incision is grasped and pulled superiorly.  Using a resorbable suture (e.g., 4-0 vicryl), the incision is  closed vertically by grasping the tissue 1 cm away from the  midline on either side of the skin hook and advancing these  edges together by tightening the suture. This provides for a  1 cm V-Y closure. The remaining closure is completed with  either a continuous suture or interrupted sutures. The closure  generally requires four or five throws of the suture (Fig. 69.27,  Fig. 69.9b).    Fig. 69.27 Vestibular soft tissue closure is performed with a running  resorbable suture. A midline V-Y closure provides support to the upper  lip and rolls the vermillion upward and outward, gives fullness to the  lip, and makes a prominent white-roll. Closure is started posteriorly and  moved anterior to bring the labial side mucosa forward, which is then,  closed in the midline in the form of an inverted “Y” (yellow arrow)    69.28 (a,b) A case of vertical maxillary excess treated with supe-  rior positioning of the maxilla showing frontal, right lateral and left  lateral views. (al, a2, a3) Pre-surgical photos of the patient; (b1, b2,   The remaining vestibular closure continues from the poste-  rior portion of the incision. A running resorbable suture (e.g.,  4-0 vicryl) is passed in a simple running fashion. Figures   depict the results achieved by the technique described above  for different clinical indications. Figure 6 demonstrates  steps involved in peforming a Lefort I osteotomy in a bi-  maxillary setting.    This high-level osteotomy is a variant of the Le fort I oste-  otomy and extends up to the lower part of the zygoma, to a  point just below the infraorbital nerve bilaterally.   The indications for this osteotomy are midface retrusion,  including excessive scleral exposure.    69 Orthognathic Surgery for the Maxilla-LeFort | and Anterior Maxillary Osteotomy    Fig. 69.29 (a, b) (al, a2, a3) Pre-surgical occlusion of the same patient as in Fig. 69.28, treated with LeFort I superior repostioning. (b1, b2, b3)    The benefits of the quadrangular osteotomy are that it  improves the appearance of midfacial retrusion and flatten-  ing and improves zygomatic prominence and support for the  lower eyelid. This osteotomy has minimal surgical morbidity  and has acceptable outcomes. This may therefore be consid-  ered, especially in Asian patients, as a viable treatment alter-  native for midfacial advancement without augmentation of  the malar region [65].   If the cuts are made from high to low a significant inferior  movement of the maxilla can be achieved thus reducing the  necessity for an interpositional bone graft (which would be    required following a maxillary set down) and alloplastic  onlay grafts for the zygomatic regions. It is more stable than  conventional inferior positioning of the maxilla as there is  good bone contact with native bone and no bone graft. This  osteotomy also produces less rotation of the nasal tip than the  conventional Le Fort I osteotomy. However, it is important to  recognize that if there is a mild facial asymmetry in the max-  illary region, this asymmetry can be emphasized with this  high-level cut as the maxilla is advanced. The surgical tech-  nique is the same as for the conventional Le Fort I osteotomy,  but significant sharp dissection of the masseter muscle from    Fig.69.30 (a, b) Patient with maxillary occlusion cant and asymmetry (also see Figs. 69.31,    the zygoma is required to expose the prominence of the zygo-  matic bone. The bony cuts are demonstrated in Fig.  The cuts are made just below the infraorbhital nerves.   The bone over the zygomatic prominence is thick, and  control over the shape of the cuts is easier using a burr and a  saw. This ensures that the bony cut does not propagate  upward to the cranial base but instead is directed downward  to the normal pterygomaxillary disjunction level. The other  steps to complete the bony cuts and down-fracture the Le  Fort I cut are made as above. Fixation is with miniplates.  However, care must be taken to ensure the plates are not pal-  pable in the infraorbital regions.    SARPE is a combination of orthodontic and surgical tech-  niques to expand the maxillary arch. This is ideal in patients  with of transverse maxillary deficiency, where the palatal    suture has completely fused. This concept initially was met  with skepticism but later was repopularized through the  works of several clinicians, including Issacson and Ingram  [66] and Haas [67], as a viable method of treating maxillary  transverse deficiency. SARPE is indicated in cases where  skeletal maturity has been achieved, transverse maxillary  deficiency is present, excessive display of buccal corridors  when smiling, and presence of anterior dental crowding. It  has been shown that the midpalatal suture undergoes ossifi-  cation at a wide range of ages [68]. In general, SARPE is  recommended for patients who are over 16 years of age [69].  Nonsurgical expansions can be a reasonable consideration  for patients younger than 12 years of age.   Before starting the surgery, it is important to confirm the  secure placement of the appliance and also the presence of  the device key to activate the appliance.   The maxilla is not down-fractured. Relieving of the oste-  otomies present at the zygomaticomaxillary buttresses is  done, as this allows clearance during separation. The midline    69 Orthognathic Surgery for the Maxilla-LeFort | and Anterior Maxillary Osteotomy    Fi (a-m) Surgical procedure for correcting the maxillary  occlusion cant (also see Figs. 30, and ). (a—c) Sagittal  split osteotomy cuts. (d) Incision marking for le fort Osteotomy. (e, f)  Osteotomy cuts marked and made for asymmetric superior reposition-  ing of maxilla. (g) Down-fracture of maxilla. (h) Superior repositioning    of maxilla. (i) Fixation of maxilla with mini plates and screws. (j) Open  bite on right side of occlusion because of asymmetric superior reposi-  tioning. (k) Unilateral sagittal split osteotomy of mandible split and  fixed with mini plates and screws. (I) New Occlusion achieved.  (m) Closure of wound done   otomy is carried out using a sagittal or piezo saw from the   piriform rim of the nose, to the alveolus. The mid-palatal 1. SARPE is usually performed on arches that are V shaped.  suture osteotomy is completed with chisels. The zygomati- 2. The scope of orthodontics is limited in masking a skeletal    comaxillary buttresses clearance is confirmed intraopera- transverse discrepancy that is greater than 5 mm. A seg-  tively by activating the palatal appliance (Fig. 69.34a-c). mental Le Fort expansion cannot be carried out for move-  The remainder of the procedure is according to Le Fort 1 ments greater than 7 mm. If a significant amount of    69 Orthognathic Surgery for the Maxilla-LeFort | and Anterior Maxillary Osteotomy 1535    Fig. 69.32 (a, b) (al, a2, a3) Pre-surgical pictures of patient with cant; (b1, b2, b3) postoperative asymmetric superior repositioning of maxilla  and unilateral sagittal split osteotomy of the mandible to close the open bite created (Also see Figs. 69.30, 69.31 and 69.40)    more stability. of maxilla.  3. An IOPA X-ray is taken to ensure that sufficient space 6. The zygomaticomaxillary buttresses offer greatest resis-  exists for an interdental osteotomy. tance to maxillary expansion. Activation of the palatal  4. Osteotomies performed during a Le Fort I are replicated appliance must be done within the operating room. This  for the SARPE procedure, without down-fracturing the will ensure that the maxilla is able to expand bilaterally,    Fig. 69.33 It is important to continue the saw or cut with a fissure  bur through the inferior part of the zygomatic arch and extend it  inferiorly and posteriorly to enable the important back cut to the  pterygoid plates. This reduces the possibility of unwanted  propagation of fractures to the cranial base    Fig. 69.34 (a) Maxilla down-fracture, paramedial osteotomy, palatal expansion device in situ, and checking for the horizontal segmental move-  ment. (b) Midline palatal osteotomy, device for palatal expansion, (c) Tooth- borne Haas & Hyrax Appliance    69 Orthognathic Surgery for the Maxilla-LeFort | and Anterior Maxillary Osteotomy    7. Overcorrection is recommended to allow for relapse. This  is because maximum instability is associated with trans-  verse maxillary expansion.   8. Either a tooth-borne appliance (Haas and Hyrax appli-  ance) or a bone-borne palatal appliance may be used. The  tooth-borne appliances may be more acceptable for  patients, as they are less invasive and more hygienic. The  disadvantage of these appliances is that they can create an  occlusal tipping effect at the level of the alveolar bone  and teeth. This may be minimized by engaging at least  three posterior teeth. On the other hand, a bone-borne  appliance offers better control over orthopedic move-  ments at the level of the palate, but it requires a steep  palatal vault for anchorage and is more invasive [71, 72].    A single surgical procedure can be employed to correct skel-  etal deformities of the mandible and the maxilla as well. The  surgeon generally determines the preferred sequence. The  authors personal preference is provided below.   1. The mandibular bony cuts are usually performed first,  without splitting the mandible. This is followed by com-  pletion of the maxillary osteotomy, repositioning and  fixation. In the past, fixation was only by trans-osseous    wiring. Hence, when the mandible was performed first, its  position was arbitrary as it incorporated the mobile proxi-  mal fragment (due to the TMJ) based on which the final  maxillary position was determined. To avoid this the  maxilla was completed first.   2. The mandible is exposed, and the bony osteotomy cuts  are completed. However the formal split is not  completed.   3. The maxilla is exposed, osteotomy completed and fixed  in its final position.   4. The split for the mandible is completed, followed by the  reposition of the mandible to the desired position. The  mandible is then stabilised and fixed in its final position.  This eliminates the possibility of any undesired maxillary  movement as the movement of the maxilla is completed  based on a stable intact mandible.   6. The same order must be considered during model surgery  and when fabricating the intermediate and final splints for  guidance.    The authors personal preference has been detailed above.  Alternatively, mandibular splitting may be performed first,  and an intermediate splint may be used to to fix the mandible  to the unoperated maxilla. The maxilla may then be stabi-  lized to the operated and repositioned mandible. However, it  must be noted that stabilization and fixation of the mandible  are more challenging than for the maxilla. Rigid fixation  may be more challenging if an improper or misdirected split  occurs. The procedure may even need to be aborted alto-  gether. However, by stabilizing the maxilla first, the mandi-  ble can use appropriately positioned maxilla for stabilization.  Therefore, we have always preferred to complete the maxil-  lary surgery before mandibular surgery.   Having listed a general guide above, we reiterate that no  dogma should be given regarding the sequence of maxillary  or mandibular surgery. Proper planning and preparation will  in turn logically dictate the sequence, which must be kept  flexible [73].    Changes in the jaw position in turn lead to changes in the  position of soft tissues such as the lips, cheeks, and nose  [74]. The lips may show thinning, reduced vermillion show,  and may lack adequate lip support [46]. The nasal tip may be  upturned, the alar base width may increase, and the nasolabial  angle may widen [75] (Fig. 69.35a—c). Soft tissue swelling    Fig. 69.35 (a-—c) (a) reduction of a strip along the caudal septum will shorten the nose; (b) reduction involving the nasal tip as shown will increase  the nasolabial angle; (¢) wedge reduction predominantly at the septal base will reduce the nasolabial angle    may take up to a year to resolve, so these changes may not be  apparent immediately [76]. In some regions, such as the sub-  nasale, and the lips, greater than 10% change has been docu-  mented over 5 years [4]. Nasal changes are quite complex  and are therefore unpredictable. Both the structure of the  nose (including nasal cartilage connective tissue, anterior  nasal spine, and the other nasal cartilages) and the degree of  movement of the maxilla play a role in nasal changes. Other  patient-related factors, including thickness and morphology  of the soft tissue, postoperative healing, age, and ethnicity,  can also affect nasal changes, which may either be favorable  or unfavorable or beneficial. The nasal width alone increases  predictably in Le Fort I osteotomies, and the increase in  width depends on the extent of maxillary movement.  Adjunctive procedures to limit widening of the nasal width  may be performed intraoperatively. These include alar cinch  suture and piriform aperture sculpting. Alternatively, the  changes may be accepted and later procedures can be per-  formed if necessary. The disadvantage of this is the need for  an additional surgical procedure, e.g., alar wedge resection  rhinoplasty. The alar cinch suture and V-Y closure (ACVY)  is efficient and less invasive in controlling nasolabial  changes. Its long-term results need to be evaluated. One  study showed that the alar base cinch suture reduced the  inter-alar width to its preoperative width following a Le Fort  I osteotomy. The suture was stable when evaluated at 12  months and 3 years postoperatively [77]. There have been    studies comparing nasal and maxillary vermilion morphol-  ogy after Lefort osteotomies by simple primary closure,  Single VY closure and Double VY closure. The results indi-  cated that better aesthetics are seen in double VY closure  cases (See Hackney et al. 1989, Ledezma et al. 2014, in  Additional reading provided). However a systematic review  in 2014 couldn’t reach a conclusion regarding the efficacy of  various methods of closure in Lefort Osteotomies.    1. Attempts to study the nasal changes resulting from maxil-  lary movements have demonstrated very variable results.  The general consensus is that nasal changes are unpre-  dictable after Le Fort I osteotomy [78].   2. The ascending pharyngeal artery and ascending palatine  artery maintain blood perfusion to the down-fractured  maxilla.   3. Impacted, unerupted, or erupted wisdom teeth may be  removed during the Le Fort I surgery. The curved pterygoid  osteotome must be placed posterior to the impacted teeth or  through the socket. The technique of pterygoid separation  through the socket of the third molar was described by  Trimble et al in 1983 (Refer additonal reading).   4. If posterior bony interferences are present, they may  cause condylar displacement, condylar distraction, asym-    69 Orthognathic Surgery for the Maxilla-LeFort | and Anterior Maxillary Osteotomy   5. If the maxilla is not mobilized sufficiently prior to fixa-  tion, this may hinder optimal advancements.   6. The zygomaticomaxillary and nasomaxillary buttresses  consist of thick struts of bone and are ideal for securing  fixation [79].   7. Blood loss is variable but rarely warrants transfusion. A  review of over 500 osteotomies concluded an average loss  of just under 300 mL, greater for bimaxillary osteotomies  and less for single jaw surgery [80].    Mommaerts et al. reported that the anterior nasal spine is a  significant component of nasal tip projection and may be  reduced to limit the degree of nasal tip rotation [81]. Betts  et al. also stated that changes in the lateral part of the piri-  form aperture significantly affected the soft tissue of the  nasal base and nasal tip projection [82].   It is important not to remove too much of the septum as  this can produce a retracted columella, which is a potentially  unattractive feature.   Osseous recontouring of the nasal crest of the maxilla  and/or resection of a portion of the caudal extent of the carti-  laginous septum is recommended to keep interference at bay.  Placement of a suture through the anterior nasal spine and    cartilaginous septum to prevent its displacement upon  removal of the nasoendotracheal tube is beneficial.    69.9.2 Effect of Changing the Inclination  (Slope) of the Osteotomy Cut    If the osteotomy cut is made in a parallel direction to the  occlusal plane and the maxilla is advanced, the maxillary  incisor exposure will increase but the face height will not  change. However, if the osteotomy cut starts high posteri-  orly and slopes downwards toward the piriform aperture,  the maxilla will move down the slope as it is advanced, thus  increasing the maxillary incisor exposure. The mandible  will subsequently rotate in a clockwise direction and the  lower anterior face height will increase (Fig. 69.36a, b).  The opposite is true for the osteotomy cuts that start low  posteriorly and slopes upward toward the piriform aperture  (Fig. 69.37a, b).    Tf an impacted maxillary wisdom tooth is indicated for removal,  this is done through the sinus floor. Using a rotary drill with a  rosette bur, the bone from the sinus floor, which lies above the  impacted tooth, is removed. Next, a tapered fissure bur is used,  and the bone just adjacent to the impacted tooth is removed.  The impacted wisdom teeth may also be sectioned if necessary    Fig. 69.36 (a, b) Diagram showing effects of the inclination (high to  low postero-anteriorly) of the osteotomy cut when advancing the max-  illa—(a) osteotomy inclination to increase incisor exposure and poten-    tially increase lower face height, (b) advancement of maxilla producing  increase of lower facial height due to downward ramp effect    Fig. 69.37 (a, b) Diagram showing effects of the inclination (low to  high postero-anteriorly) of the osteotomy cut when advancing the max-  illa—(a) osteotomy inclination to reduce incisor exposure and poten-    to aid in removal; this usually depends on the developmental  stage. The tooth is delivered using a dental elevator. Rarely,  perforation through the palatal mucosa may occur.    If the maxillary wisdom tooth is completely erupted, this  may be extracted prior to down-fracture. This will allow the  operator to have a stable “workbench” during extraction. In  order to maintain the blood supply to the down-fractured  maxilla, the adjacent palatal and labial mucosa must be pre-  served carefully at the time of extraction.    The pre-surgical workup and planning of patients who require  corrective jaw surgery required detailed analysis of clinical  features, study models, and plane radiographs. Radiographic  analysis includes comprehensive assessment of lateral cepha-  lograms, postero-anterior cephalograms, and orthopantomo-  grams. The need for multiple individual planar views has  been replaced by the advent of cone beam technology.    Horizontal osteotomy of the maxilla should result in a clean  pterygomaxillary separation to subsequently allow for    tially reduce lower face height, (b) advancement of maxilla producing  reduction of lower facial height due to upward ramp effect    down-fracture and mobilization. At this step, the pterygoid  plates should ideally remain intact and attached to the skull  base. However, in some exceptional cases, such as patients  with cleft maxilla, the pterygoid plates are unusually thick  and well buttressed. On the other hand, some patients have  thin and almost translucent pterygoid plates [83].  Pterygomaxillary synostosis (fusion) may be seen in up to  12% of all patients [21].   If the pterygoid plates fracture at a lower level, this may  cause difficulties in down-fracture and mobilization, because  of the attachment of the pterygoid musculature. On the other  hand, if the plates fracture at a higher level, the fracture may  propagate into and along the skull base, which can poten-  tially cause neuro-ophthalmic complications.   On postoperative CT scans, the incidence of pterygoid  plate fracture after a Le Fort I osteotomy was found to range  from 58 to 75% [84, 85]. However, despite this high inci-  dence, the incidence of fractures propagating to the skull  base/orbit is low [83].   These authors stated that if a difficult down-fracture was  encountered after a routine Le Fort I osteotomy, then the pos-  terior walls of the maxilla must be sectioned completely using  an osteotome. Alternatively, sectioning through the tuberosity  could be performed, using a micro-oscillating saw or straight  osteotome, as this would avoid the thick posterior walls and  aid in pterygomaxillary separation. However, these authors  have stated that it would not be possible to totally prevent    69 Orthognathic Surgery for the Maxilla-LeFort | and Anterior Maxillary Osteotomy    untoward fractures that could occur during pterygomaxillary  disjunction and down-fracture. We emphasize that thorough  CBCT imaging should be undertaken preoperatively, as this  would familiarize the surgeon with the maxillary  morphology.   The following maneuvers may help if the surgeon finds dif-  ficulty in down-fracture following osteotomy and disjunction:    1. Revise the osteotomy cuts at all accessible sites, includ-  ing anteromedial antral, lateral antral, and superior-nasal  crest.   2. The maxilla may be “hinged down” to directly visual-  ize the posterior maxilla, after which the cuts in this  region may be completed, using a straight 4 mm  osteotome.    O’Regan and Bharadwaj stated that an osteotome or saw  must never be used blindly in these situations [86].    Fig. 69.38 (a-—c) (a) The  proper method for condylar  seating at the time of  maxillary positioning prior to  fixation. Posterior  prematurities are best  appreciated with this method.  (b) Pressure on the chin to  push the anterior aspect of the  maxillary osteotomy together  may rotate the condyles  inferiorly and posteriorly  while maxillary fixation is  applied. (c) Upon release of  intermaxillary fixation, the  condyles may return to the  fosse, and an open bite may  appear. Unfortunately, this  open bite may not appear  immediately, especially if  postoperative elastics are used  to “guide” the occlusion    e Proper positioning can be difficult in isolated maxillary  surgery, usually due to unrecognized posterior bony  interferences.   ¢ With an unrecognized posterior interference and inadequate  effort or improper seating of the condyles, the maxilla can  rotate around this interference, resulting in an anterior open  bite after release of intermaxillary fixation. The maxillo-  mandibular complex should be rotated with pressure seating  the condyles in the glenoid fossa (Fig. 69.38a, b, c).   ¢ Looking for the posterior interferences and eliminating  them will result in the intended postoperative occlusion.  Prior to any attempt to position the maxilla, effort is  devoted to removing bone in the most likely areas of  potential posterior interference, that being the area poste-  rior to the second molar and along the perpendicular pro-  cess of the palatine bone.   ¢ Whether or not there is a potential for interference in the  region of the pterygoid plates, per se, depends upon the    surgical move. This is much less likely with advancement  than it is with other moves such as impaction.   e It is often easiest to adapt the plates for fixation with Le  Fort osteotomy and initially secure them only to the infe-  rior fragment. Once all the plates are properly bent and  secured to the inferior fragment, the maxillomandibular  complex and condyles can be positioned with great care,  and the shape and bending of the plates critically evalu-  ated and secured to the superior fragment in succession,  while the maxillomandibular complex is held in position.    Orthognathic surgery throws up many physiological chal-  lenges. These include postoperative facial swelling and  catabolism which increase the nitrogen requirements. If  these are not met, wound healing may be compromised. A  diet fortified with macro- and micronutrients and adequate  hydration is therefore essential [87].   Mandibular movements may be restricted in the postop-  erative period, owing to facial swelling and pain. Meeting  the daily nutritional needs and hydration requirements  (Table 69.1) may therefore be difficult. Studies have shown  that in 6 weeks following surgery, patients can lose between  3.1 and 6.8 kg of weight [88].   It is important to adapt the diet to suit these needs, to pro-  mote wound healing, and to minimize postoperative compli-  cations. Another important factor in patient recovery is the  patient’s mood. Adequate nutrition and hydration will serve  to improve the patient’s mood, thereby diminishing postop-  erative irritability or depression [89]. Dietician assessment  of nutritional status is essential to ensure that the above goals  are achieved.   The modification of the diet is a sequential process. This  aims at reducing the masticatory forces on the underlying  healing bone, which in turn optimizes the conditions for  healing.    1. The first 7 days following surgery should consist of a diet  rich in energy and protein. This must be in a liquid form,  and foods may be completely blended in a food processor  to a smooth liquid consistency.   2. After the first week, patients can start consuming food  with a small spoon or fork. It is still advised to minimize    Table 69.1 Recommended postoperative nutrition requirements for  patients above 16 years, undergoing orthognathic surgery [87]    Energy (kcls) Protein (g) Fluid (ml)  Male 2500 1 g/kg/day 35 mL/kg/day  Female 2000 1 g/kg/day 35 mL/kg/day    chewing, and foods may be mashed. The high-energy-  high-protein diet must be continued.   3. After the second week, light chewing may be done, and a  soft diet is recommended. The jaw muscles may fatigue  easily at first, but gradually the muscles adapt to the new  position. The soft diet is continued for two months, after  which regular diet may be resumed [87, 90-98].    1. Hardware failure: Unstable orthoappliance, splints/wafer,  must be tried separately on each arch pre-operatively.  Hardware exposure or fracture, palpable hardware, and  loosening of screws are certain complications in hardware  failure. Management involves removal of hardware with  or without replacement, depending on the amount of bone  union and time duration after surgery.   2. Unanticipated fracture of maxilla: A occlusal splint with  a palatal vault extension is essential to counter this  complication.   3. Hemorrhage: Bleeding commonly occurs from the  descending palatine artery and pterygoid plexus. Injury  to pterygoid plexus may happen while performing ptery-  gomaxillary disjunction. This may lead to arteriovenous  malformations which may cause life-threatening bleed-  ing 2-4 weeks post-surgery. It needs to be managed with  selective embolization. Hemorrhage may occur in  patients with undiagnosed bleeding disorders.   4. Deviated nasal septum: This can occur when inferior  septoplasty is inadequate during superior repositioning  of the maxilla. It is managed postoperatively with  adjunctive septoplasty.   5. Damage to apices of teeth: The horizontal osteotomy  should be placed at least 5 mm above the apices of the  maxillary teeth to avoid damage to the apices.   6. Malunion and nonunion: This can occur if fixation is  inadequate fixation or has failed.   Rigid fixation with plates provides the initial stabil-  ity until bone has united. Bone first unites in the ptery-  goid region [99]. The most stable maxillary movement  is superior repositioning, followed by advancement,  and the least stable is inferior repositioning. However,  the studies looking at the inferior positioning of the  maxilla have been based on the need for bone grafting.  Studies have reported relapse rates for maxillary supe-  rior repositioning of the maxilla ranges from a mean of  0-18% for the anterior maxilla and 6—7% for the pos-  terior maxilla. Relapse rates for maxillary advance-  ment range from 5 to 15%. As with most orthognathic  surgery, relapse is greater with increase in the maxil-  lary advancement. With inferior maxillary reposition-    69 Orthognathic Surgery for the Maxilla-LeFort | and Anterior Maxillary Osteotomy    ing (using bone grafts), there may be 28% anterior  relapse and up to 70% posterior relapse [100].  Nonunion is rare and probably associated with failure  of the initial plate fixation and poor bony contact. If  this persists for greater than 6 months, further surgery  with rigid fixation and autogenous bone grafting is rec-  ommended [101]. Maxillary advancement and poste-  rior and superior movements are shown to be stable,  whereas inferior and transverse movements are unsta-  ble [99-110]. The use of autogenous bone grafts and/or  hydroxyapatite has been proposed to improve the sta-  bility of inferior repositioning of the maxilla [101,  111-117].   7. Unfavorable aesthetic result: This results from poor  treatment planning or unrealistic patient expectations.   8. Infection: Infection may occur in rare cases and is man-  aged with systemic antibiotics with or without place-  ment of a drain and the causative hardware removal.  Septic complications have been recorded in 1.1% of  osteotomy operations [55].   9. Dental problems: As a result of the osteotomy cut, the  maxillary teeth lose their nerve supply. Generally, the  nerve supply is re-established after 18 months to 2 years  [118]. The teeth maintain their viability from the collat-  eral blood supply. Patients should be warned that their  teeth and gingivae may be numb for up to 2 years [119].  Osteotomy cuts should be a minimum of 5 mm above  the root apices to avoid complications.   10. Trigeminocardiac reflex (TCR): The stimulation of tri-  geminal nerve branches during Le Fort I osteotomy can  be a possible cause of the TCR, and transient cessation  of the procedure is adequate to allow the heart rate and  blood pressure to normalize and dysrhythmia to stop  [120].    (a) Virtual planning in Orthognathic Surgery: the last  decade has seen a tremendous evolution in the field  of surgical planning. Computer Assited Virtual  Surgical Planning and the use of CAD-CAM designed  splints have significantly improved intra-operative  accuracy of maxillary repositioning in orthognathic  surgery [121].   (b) Waferless Orthognathic Surgery: Another technique  which has created a paradigm change is the design of  custom-fabricated cuttiing stents and patient specific  implant for fixation, which help not only perform the  osteotomy but also fix the segment in the desired posi-  tion without the use of occlusal wafers [122].    The development of modern maxillary orthognathic surgical  procedures had diverse historical origins and contributions.  With advancement in technique and the introduction of safe  hypotensive anesthesia, the Le Fort I osteotomy has been  increasingly utilized over the last four decades. Over the years,  various modifications of the osteotomies, ORIF methods and  bone grafting to the mobilized maxilla, have continued to  evolve and progress. The Le Fort I osteotomy of the maxilla is  one of the core procedures in orthognathic surgery for the  management of facial skeletal deformities. The surgery, often  used in conjunction with the bilateral sagittal split osteotomy,  is used to correct functional and cosmetic irregularities in all  three planes of space and can be utilized in the treatment of a  wide range of malocclusions. Traditionally, the surgery has  been known for its low technical difficulty and dependable  results. Changes in the soft tissue of the nose, lips, and cheeks  due to this surgical procedure need due consideration.   The risk of complications is higher in patients with seg-  mental Le Fort 1 osteotomies or anterior movements greater  than 9 mm. Efforts to minimize maxillary movement (e.g.,  with two-jaw surgery) are recommended to reduce complica-  tions. An emphasis should be placed on proper pre-surgical  orthodontics and solid pre-surgical planning to ensure predict-  able and stable results. It is also imperative to plan and provide  for optimal nutrition as Orthognathic surgery throws up many  physiological challenges that may compromise the nutritional  status including catabolism, postoperative facial swelling, and  increased nitrogen requirements to promote wound healing.  The premise of maxillary orthognathic surgery is therefore a  multidimensional approach through planning, execution, and  postoperative management.   Disclosure Authors have no financial conflicts to disclose.  Authors have written consent and reconfirmation from the  patients for the use of clinical pictures.    (A) Chief Complaints  Gummy smile  Long face  Deficient chin  Protruding upper front teeth    Fig. 69.39 (a—h) Vertical maxillary excess with mandibular defi-  ciency. Treatment: Le fort I with superior repositioning of maxilla;  bilateral sagittal split ramus osteotomy advancement; advancement  genioplasty. (a) Pre-operative profile picture; (b) pre-operative frontal    Fig. 69.40 (a-—i) Facial asymmetry with maxillary occlusal cant, devi-  ation of chin (surgery for left TMJ ankylosis and genioplasty done pre-  viously elsewhere). Treatment: Le fort I osteotomy for correction of  maxillary occlusal cant; right unilateral sagittal split ramus osteotomy  to close the open bite. (a) Pre-operative profile picture; (b) pre-opera-    view; (Cc) pre-operative lateral cephalogram. (d) Pre-operative OPG; (e)  postoperative lateral profile; (f) postoperative frontal view; (g) postop-  erative lateral cephalogram; (h) postoperative OPG showing the  implants and the osteotomy cuts in mandible. (Also see Fig. 69.28)    tive frontal view; (c) pre-operative PA skull; (d) pre-operative OPG; (e)  pre-operative lateral cephalogram; (f) postoperative profile picture; (g)  postoperative frontal view; (h) postoperative PA skull; (i) Post-operative  OPG (Also see Figs. 69.30, 69.31 and 69.32)    69 Orthognathic Surgery for the Maxilla-LeFort | and Anterior Maxillary Osteotomy    Surgical Procedure  Le fort I osteotomy for superior repositioning of maxilla  Bilateral Sagittal Split Ramus osteotomy for advance-  ment of mandible  Advancement genioplasty  Later rhinoplasty was done.   Facial asymmetry was secondary to ankylosis of left  TMJ. Left side treated with costochondral graft when patient  was younger.   The patient presented with occlusal canting visible at the  anterior region. This needed to be addressed as it is clinically  evident and may affect visual cosmesis.   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Esthetic evaluation of fron-  tal labial morphology after double V-Y closure following Le Fort I  osteotomy. J Oral Maxillofac Surg. 1989;47(12):1277-80; discus-  sion 1281.   Khamashta-Ledezma L, Naini FB. Systematic review of changes in  maxillary incisor exposure and upper lip position with Le Fort I  type osteotomies with or without cinch sutures and/or VY closures.  Int J Oral Maxillofac Surg. 2014;43(1):46-61.    Open Access _ This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.  org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropri-  ate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.   The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in  a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.   Physical appearance is of much significance to the humans,  as the human mind perceives the slightest form of deviation  from normal form, function, and symmetry of the body and  especially of the face as it is easily discernible [1]. Facial  asymmetry could be defined as a clinically perceptible and  significant difference between the two halves of the face.  Every individual has some degree of asymmetry which may  provide a uniqueness to the face. However, the magnitude  and acceptability of the same depend on the location of the  asymmetry and the patient’s perception of disproportion.  Facial asymmetry may also adversely affect the patient’s  nutritional and psychosocial development [2].   Any abnormality of the soft or hard tissues can lead to  asymmetry. This could be a consequence of a congenital  anomaly, a developmental, or an acquired defect. Asymmetry  can be progressive in nature, while those acquired due to  trauma or ablative surgeries are non-progressive [2, 3]. It is  prudent for the clinician to consider the aetiology of the  asymmetry, the extent, and its severity in all three dimen-  sions in order to provide an optimal treatment plan. Besides,  it is important to take into consideration factors such as  growth, timing of treatment, and psychological aspirations  of the patients when deciding the treatment plan [3, 4].   The present chapter will discuss the etiopathogenesis and  classifications, clinical considerations, and diagnosis, evalu-  ation, and treatment planning of facial asymmetries. Few  interesting case scenarios will also be discussed for a better  understanding of clinical presentations and __ their  management.    N. N. Andrade  - P. Mathai - N. Aggarwal  Department of OMFS, Nair Hospital Dental College, Mumbai  Central, Mumbai, India    © The Association of Oral and Maxillofacial Surgeons of India 2021    Understanding the etiopathogenesis and classification of  facial asymmetry allows for accurate diagnosis, optimal  treatment planning, and improved surgical outcomes. Facial  asymmetries are most commonly classified according to  aetiology or morphology. Other classifications are based on  time of onset, structures involved, and surgical planning out-  comes and may even be restricted to the mandible alone.  Table 70.1 is a summary of the various classification systems  available to us today [5-19].   We have identified three classifications that are essential  for the evaluation and treatment planning of facial asymme-  tries [Table 70.2 by Cheong et al. (2011) [13], Table 70.3 by  Wolford et al. in (2009) [11], Table 70.4 by Wolford et al.  (2014) [2, 19-21]].    Facial asymmetry is usually the least at the cranial base level  and increases toward the lower levels of the face, with the  mandible and chin commonly exhibiting the greatest asym-  metry. Hence, the cranial base is used as a reference plane for  assessing the type and severity of the asymmetry in the mid-  dle and lower thirds of the face. Conditions where the cranial  base is also involved like syndromic or non-syndromic cra-  niosynostosis, tumors of the cranium, and midface and  Tessier’s craniofacial clefts cannot be assessed in a routine  manner. The presence of orbital dystopia, unequal pupillary  heights, and/or unequal ear heights will make the assessment  more challenging [2, 20, 22, 23].   Every clinical examination begins with identifying the  chief complaint of the patient followed by a detailed physical  and medical evaluation of the patient. In order to better  understand the facial asymmetry, it is studied in the sagittal,  coronal, and vertical dimensions with the cranial base as the  reference plane. Common facial planes that represent the    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1-15-1346-6_70    Author  Pirttiniemi,  1994 [5]  Bishara, 1994  [6]  Lundstrom,  1961 [7]  Plint, 1974  [8]   Pre-natal [further divided into  embryonal and fetal] and post-natal  Dental, skeletal, muscular,  functional, and combination  Genetic, non-genetic, and  combination   Laterocclusion [apparent  asymmetry due to occlusal  disharmony] and laterognathism  [true facial asymmetry |  Pathological, functional, traumatic,  and developmental   Hereditary factors of pre-natal  origin and acquired factors of  post-natal origin  Pseudo-asymmetry, normal facial  asymmetry [non-pathologic],  unilateral overdevelopment, and  unilateral underdevelopment  Congenital, developmental,  post-traumatic, and  pathology-related   Congenital [pre-natal origin],  acquired [injury or disease], and  developmental [unknown origin]  Congenital [malformation,  deformities, and disruptions],  developmental [primary and  secondary growth deformities],  acquired [trauma and pathology],  and idiopathic    Hemi-hyperplasia [hemifacial  hypertrophy], Hemi-hypoplasia  [hemifacial microsomia], Hemi-  atrophy [Parry Romberg  syndrome], and miscellaneous  entities [hemi-maxillofacial  dysplasia]   TML system for optimal surgical  planning in mandibular  prognathism cases only: menton  deviation with transverse  asymmetry [T], maxillary cant [M],  and lip cant [L]   Based on deviation of the chin and  bilateral difference between  mandibular rami length   Restricted to condylar hyperplasia  [CH] only: Type 1 CH [prolonged  accelerated growth], Type 2 CH  [osteochondroma], Type 3 CH  [benign tumors other than  osteochondroma], and Type 4 CH  [malignant tumors]    Table 70.2 Major etiological factors of facial asymmetry, according  to Cheong et al. (2011) [13]    cranial base are the pupillary plane, the ear plane, and the  clinical Frankfort horizontal plane. It is also important to  note that patients may hold the head in an abnormal position  or use hairstyles and mannerisms to mask the extent of the  asymmetry [e.g., a patient with a deficient mandible may tip  his head upward in order to improve chin projection]. It is  important to identify these compensatory mechanisms dur-  ing the treatment planning process. Similarly, it can be ben-  eficial to study the lower or middle third individually in  comparison with the unaffected upper third [cranial base] by  blocking out the part not being studied with an opaque sheet  [e.g., card board] [20, 23].   The patient’s head is positioned such that the interpupillary  plane or ear plane [passing through the bottom of the ear  lobes or tragi of the ears] is parallel to the floor. The pupillary  plane can also be used for assessing bilateral vertical dis-  crepancies by measuring height differences from the plane to  the mandibular angles, chin, nose, and commissures  (Fig. 70.1). The facial midline is represented by a vertical  plane passing through the nasion or glabella, perpendicular  to the pupillary plane and ear plane (Fig. 70.2). It allows to  compare the degree of left-to-right asymmetry and trans-  verse facial width discrepancies of various facial structures  [e.g., orbits, pupils, malar eminences, nose, commissures,  and mandibular angles]. In case of some imbalance in the  frontonasal region [e.g., past naso-orbito-ethmoidal trauma],  other landmarks can also be used as a reference to identify  the facial midline, e.g., half the interpupillary or inter-canthal  distance, the subnasal point, or the philtrum [20, 22].    Occlusal interferences Genetics Condylar hyperplasia / Mandibular  hyperplasia/Deviant prognathism  Neuromuscular Intrauterine | Osteochondroma/osteoma  dysfunction moulding  Habitual posturing Natural Unilateral muscle hyperplasia [masseteric  growth muscle hypertrophy]  variance   Acquired: trauma, infection, TMJ ankylosis, and  iatrogenicities [due to tumor resection, radiation,  unstable orthognathic procedures and adverse surgical  events], failed TMJ alloplastic implants, and failed  autogenous tissue grafts    Congenital deformities [unilateral cleft lip and palate,  hemifacial microsomia, and Treacher Collins  syndrome]    Adolescent idiopathic condylar resorption  TMJ reactive [inflammatory] arthritis  Connective tissue and autoimmune diseases    Age at  CH type onset Clinical findings Imaging  CH Type 1 [similar Puberty Type 1A Bilateral [BL]  to hemi-mandibular or Type 1B Unilateral  elongation]: Type [UL] accelerated growth; head shape  1A and Type 1B self-limiting; Class 3  occlusion; prognathic  mandible  CH Type 2 [similar Two-thirds UL vertical elongation of  to hemi-mandibular of cases face and jaws; non-self-  hyperplasia]: Type —_ begin in limiting; ipsilateral  2A and Type 2B 2nd decade posterior open bite;  occlusal cant  occasionally  CH Type 3 No specific UL facial enlargement  age  CH Type 4 No specific UL facial enlargement  age    The patient should be reminded to relax the peri-oral  musculature for assessing the tooth to upper lip relation at  rest [e.g., patients with vertical maxillary excess will con-  stantly purse their lips to reduce excessive gum and teeth  show]. The smile needs to be assessed for the amount of  gingival show on either side, tooth to upper lip relation, com-  parison of dental midline with facial midline and symmetry  by comparing parallelism of commissural and pupillary  lines. Finally, a tongue blade or thin ruler can be placed  between the maxillary and mandibular canines and premo-    Unilateral vertical enlarged condylar  head, neck, ramus and body; Type  2A: Enlargement without horizontal  exophytic growth of the condyle;  Type 2B: enlargement with  exophytic growth of the condyle  Varies from normal anatomy of  condyle; usually presenting as  condylar enlargement    Varies from normal anatomy of  condyle; usually presenting as  condylar enlargement with lytic   Normally growing condyle; may show  chondrocyte proliferation during initial  and active phases, with normal bone  after growth ceases    Osteochondroma; cartilaginous cap  similar to that seen in a normal growth  cartilage; endochondral ossification;  cartilaginous islands in the sub- cortical  bone; thickened irregular bony  trabeculae    Benign tumors, e.g., osteoma,  neurofibroma, giant cell tumor, fibrous  dysplasia, chondroma,  chondroblastoma, and arterio-venous  malformation   Malignant tumors, e.g.,  chondrosarcoma, multiple myeloma,  osteosarcoma, metastatic lesion, and  Ewing’s sarcoma    lars to assess the presence of a cant in relation to the pupil-  lary plane (Fig. 70.2). Comparing the vertical heights from  the pupillary plane to the canine tips on either side can help  quantify the cant. An occlusal plane inclination of greater  than 4° is said to cause significant perceptible asymmetry.  Assessment of midline structures such as nasal bridge,  nasal tip, philtrum, and the chin point should also be carried  out. Submental [worm’s-eye] (Fig. 70.3) and superior [bird’s-  eye] views (Fig. 70.4) are very useful in assessing deviation of  the abovementioned structures. We can also assess symmetry    Fig. 70.1 Various facial planes A horizontal plane (interpupillary  plane) B horizontal plane (inter tragal plane) C horizontal plane (plane  marked through ear lobes) D vertical plane (mid-sagittal plane)    and projection of the anterior cranial vault, orbital areas, nose,  cheeks, malar eminences, and mandibular body contours.    Profile View  In order to avoid underestimating the severity of the facial  asymmetry due to compensatory head postures, it is    Fig. 70.2 Occlusal cant in relation to the pupillary plane and asym-    essential to position the head so that the clinical Frankfort  horizontal plane (a line from the tragus of the ear through  the palpable bony infraorbital rim) is parallel to the floor  (Fig. 70.5). The patient should also be reminded to relax  the peri-oral musculature to better assess the tooth to  upper lip relation at rest. Evaluating the left and right    sides from the profile view will allow assessment of dis-  crepancies in the antero-posterior and vertical dimensions  [e.g., maxilla, mandible, and chin] rather than asymmetry  evaluation.    Orthodontic study models mounted in centric relation by  face-bow transfer onto a semi-adjustable anatomic articu-  lator help in dento-alveolar and occlusal assessment with  a further advantage of studying the occlusion from the lin-  gual aspect. The dental arches are evaluated for overde-  velopment, underdevelopment, presence of yaw, and  asymmetry in the antero-posterior, transverse, and verti-  cal planes. The dental examination should include the  presence or absence of missing, deformed, carious,  impacted, or ankylosed teeth; dental midline shift; dental  crowding or spacing; congenital deformity [e.g., cleft  alveolus in a case of cleft lip and palate]; habitual pattern  [e.g., tongue thrusting or thumb sucking]; pathology; and  size of tongue and trauma (Figs. 70.6, 70.7, and 70.8).  These findings can be incorporated into the treatment  planning.    Fig. 70.7 Crowding in both arches along with a reverse overjet    Fig. 70.8 Nonco-incident dental midlines (blue-upper dental mid line,  yellow-lower dental midline)    A dedicated photography room where extra-oral and intra-  oral photographs are taken under standardized settings [e.g.,  lighting, background, focal length, and distance-to-subject]  is ideal. Extra-oral photographs of the frontal [with and with-  out smile, occlusal and mandibular inferior border cant],  three-quarter, submental, and superior views are essential for  the assessment of facial asymmetry. Intra-oral frontal, lat-  eral, superior [45° to the occlusal plane from above], and  inferior [45° to the occlusal plane from below] views with  the teeth in occlusion are essential for dento-alveolar assess-  ment [11, 23-26].    The three primary radiographic examinations performed in  the assessment of facial asymmetry are lateral cephalometry,  postero-anterior cephalometry, and orthopantomography.  They have been described briefly below. As a rule, serial  cephalometric assessment every 6 months for a minimum  duration of 1 year may be helpful in determining if the asym-  metry is static and stable or if it is progressive [24, 25].    1. Lateral Cephalometry:  It is used to assess hard tissue and soft tissue relationships  in 2D, i.e., antero-posterior and vertical dimensions. This  tool is less commonly used to assess facial asymmetry.  The head is placed into a reproducible position within the  cephalostat with the help of the nasal bridge indicator and  ear roads which closely approximates the clinical  Frankfort horizontal plane. The patient keep should also  be instructed to keep the jaws in centric relation with the  teeth lightly touching and the lips slightly parted or  relaxed. The ability of the cephalostat to reproduce the  near about the same position every time allows for com-  parative cephalometric analysis and super-imposition of  tracings. Bilateral vertical discrepancies [e.g., increased  vertical dimension of the body and ramus-condyle unit of  the mandible in unilateral condylar hyperplasia type 2]  can usually be assessed in a lateral cephalogram. The  right and left sides are presented as two separate non-  super-imposing lines, and this can be measured as a  discrepancy between the two images of the occlusal plane  and inferior borders of the mandible (Fig. 70.9).  2. Orthopantomograph [OPG]:   The OPG is an excellent tool to evaluate mandibular  asymmetry and dental status. The anatomy of the con-  dyle—ramus unit, body, and inferior border of the man-  dible is readily discernible. Increase or decrease in  dimensions or changes in mandibular morphology can be  studied. In cases of unilateral asymmetry, the affected side    can be compared to the normal side. The course of the  inferior alveolar nerve can also be assessed and is of vital  importance if an inferior border osteotomy is being per-  formed [e.g., inferior border osteotomy in cases of unilat-  eral condylar hyperplasia type 2 where the inferior alveolar  nerve might be coursing near the lower border of the man-  dible] (Fig. 70.10). The OPG is also an excellent tool for  the screening of maxillofacial pathology that may cause  facial asymmetry, e.g., tumors and fibro-osseous lesions.    Fig. 70.9 Lateral cephalogram showing double images of the inferior  border of the mandible (blue arrows) along with displaced IAN canal  (yellow arrow) in a case of type 2 condylar hyperplasia    Fig. 70.10 OPG demonstrating the difference in height of the man-  dibular body (blue arrows), displacement of the IAN canal toward the  inferior border (yellow arrows)    The PA cephalogram allows a comparative study of the  symmetry between the structures of the right and left  sides. Projections can be obtained in both open mouth  position and centric occlusion with head oriented in natu-  ral head position to identify the full extent of static and  dynamic [functional] asymmetry. The horizontal refer-  ence plane is represented by a line passing through the  bilateral zygomatico-frontal sutures. The vertical refer-  ence plane is a line perpendicular to the horizontal plane  passing through crista galli. Transverse and vertical dis-  tances of various facial structures are measured by draw-  ing perpendicular lines drawn from the structures in  question to the vertical and horizontal reference planes.  By comparing the distances measured bilaterally, the type  and extent of the underlying asymmetry can be assessed.  Additionally, a shift in the dental midlines can be assessed  by comparing them to the skeletal midline. The Grummons  and Ricketts analyses are commonly used PA cephalo-  metric analyses for the evaluation of facial asymmetry  (Fig. 70.11).   The main advantage of the 3D CT scan is that it helps in  visualization and treatment planning of complex facial  asymmetry in cases like craniosynostosis, Treacher  Collins syndrome, hemifacial microsomia (Figs. 78.4,  78.5 and 78.6), TMJ ankylosis, and unilateral condylar  hyperplasia (Fig. 70.12a, b). Unlike cephalometric and  panoramic radiographs, there is no superimposition of  structures, the absolute position of anatomical landmarks    Fig. 70.12 (a, b) 3DCT face analysis for assessing the facial asym-  metry. Various parameters include, Arbitrary horizontal reference plane  assuming orbits are normal (black); FH plane (purple); mandibular  height [canine to mandibular plane (orange)]; maxillary height (first    can be defined, and viewing is possible from any angle. It  is also an excellent tool for patient education. The CT  scan data can be used for fabrication of stereolithographic    Fig. 70.11 Grummons and Ricketts analysis using PA Cephalogram  for evaluating the facial asymmetry. Horizontal reference plane (red);  vertical reference plane (yellow); ramal height (blue); intercuspid width  (green); intermolar width (purple). Refer to additional reading    molar to FH) (red); ramal length (Co superior to Go inferior) (green);  occlusal plane (yellow); lateral ramal inclination (Co superior to Go  posterior to FH) (brown); midsagittal plane (light blue)    medical models which help make surgical planning even  easier. The disadvantage of the CT scan is the exposure to  a high radiation dose; with the introduction of the CBCT,  the amount of radiation exposure has been greatly  reduced. 3D reconstruction, stereolithographic model  printing and integration with 3D stereo photogrammetry  data allows for treatment planning, treatment simulation,  and assessment customized according to the patient [e.g.,  Dolphin 3D, IPS by KLS Martin]. Lastly, both CT and  CBCT provide valuable information regarding the hard  tissue status of the TMJ and aid in the diagnosis of reac-  tive [inflammatory] arthritis of the TMJ, osteoarthritis of  the TMJ, idiopathic condylar resorption, avascular necro-  sis, and degenerative remodeling of hard tissues of the  TMJ in dentofacial asymmetries [24, 25].  5. Magnetic Resonance Imaging:   MRI is primarily used to study the soft tissues of the TMJ  [e.g., disc, capsule, ligaments] and combined with the  CT/CBCT scan data is able to accurately diagnose  reactive [inflammatory arthritis] of the TMJ, internal  derangements, condylar resorption, and degenerative  remodeling of soft tissue of the TMJ in dentofacial asym-  metries (Fig. 70.13a, b) [e.g., thinning and displacement  of the disc of the contralateral unaffected TMJ in cases of  unilateral condylar hyperplasia] [24, 25].    70.3.5 Stereophotogrammetry  It is the construction of a three-dimensional model based    on the positions of recognizable points or landmarks in  several different photographs. It utilizes two or more cam-    eras configured to capture a pair of stereo images of the  surface of patient’s face which are then used to generate a  3D image of the face by triangulation performed through  sophisticated stereo algorithms. The technique is mini-  mally invasive and has an expanded coverage of close to  360° of the structure being studied with quick capture  speeds (often under | second). These advantages make it is  particularly useful when working with young children  [with craniofacial deformities] for whom quantification of  facial features can be challenging [25, 26]. The ability to  store images for subsequent use, accurate reproduction of  the surface geometry of the face, and ability to map realis-  tic color and texture data onto the recorded geometric  shape make this technique the preferred facial surface  imaging modality over older conventional imaging modal-  ities like laser scanning [26].    Medical modelling involves first acquiring a CT, CBCT, or  MRI. This data consists of a series of cross-sectional images  of the region being studied. The selected part is now created  in a layer-by-layer fashion using photopolymerization ulti-  mately forming a three-dimensional solid. The use of such  models in maxillofacial surgery has significantly improved  predictability of clinical outcomes in facial asymmetry cases  when compared to similar treatments without its use. The  models facilitate direct visualization of complex 3D facial  asymmetry, decrease operating time due to better treatment  planning, and can also be used as an educational tool for  patients (Fig. 70.14) [27].    Fig. 70.13 (a, b) MRI of TMJ showing anteromedial disc displacement (yellow arrows)    Fig. 70.14 Facial asymmetry demonstrated on STL model involving  both the midface and mandible with hyperplasia involving the right side    Virtual treatment planning — web meeting/video conferencing (for sequence of treatment planning)   Figure 70.15 shows the sequence involved in VSP/  CASS. The advantages are an increased dental relationship  accuracy, reduced OR time, increased patient satisfaction,  and decreased costs. Simulating surgery preoperatively  allows measurements to the 1/100th of a millimeter, and  when combined with 3D-printed splints and customized pre-  bent plates, the reconstructive and aesthetic outcome is supe-    Fig. 70.15 Flow chart outlining the steps involved in virtual surgical planning has been reproduced after permission from the article “Farrell BB,  Franco PB, Tucker MR. Virtual surgical planning in orthognathic surgery. Oral Maxillofac Surg Clin North Am. 2014; 26(4):459-73” [28]    TMJs must be healthy for predictable orthognathic surgery  outcomes. The TMJ must be assessed before and after  orthognathic surgery for joint noises (clicking and popping),  localized tenderness, radiating facial [e.g., headaches] and  neck pain, and limitation of mouth opening and jaw locking.  The literature reports a higher incidence of TMD in patients  with retrognathic mandibles and in those with steep occlusal  planes [29, 30].   There is no conclusive evidence regarding the effect of  orthognathic surgery on TMD with opinions split between  improvement, no change, or worsening of signs and symp-  toms. However, high-angle, class II patients with pre-existing  TMD undergoing counterclockwise rotation or large man-  dibular advancement procedures are known to experience  worsening of symptoms. Figure 70.16 is the Boston  University Protocol for the management of facial asymmetry  requiring orthognathic surgery with pre-existing TMD [29].    A bone scan is a nuclear imaging test that involves injecting  a small amount radiotracer that into the bloodstream. The  radiotracer travels through the area being examined and  gives off radiation in the form of gamma rays which are  detected by a special gamma camera and a computer to cre-  ate images of your bones. Thus, skeletal scintigraphy offers  the potential to identify disease in its earliest stages as it is  able to identify any abnormal increases in metabolic activ-  ity [31].   Cisneros first used bone scintigraphy to study mandibular  asymmetry in patients [31]. There are two types of bone scan  techniques commonly used: skeletal scintigraphy [subtypes:  planar bone scanning and single-photon emission-computed  tomography] using technetium-99m methylene diphosphate  and positron emission tomography [subtypes: with and with-  out CT, full ring and half ring] using radiolabeled 18F-2-  fluoro-2-deoxyglucose [glucose analog].   Planar [regular] scintigraphy is not very accurate as it is  only a two-dimensional assessment of three-dimensional  anatomy. On the other hand, SPECT [single-photon emis-  sion computed tomography] allows three-dimensional  assessment as the isotope is dispersed in the subject’s body  thus allowing spatial localization of the pathology in the  mapped body organ.    Dedicated/full-ring PET [as compared to half-ring PET]  provides better spatial resolution than a planar bone scanning  and SPECT (Refer Fig. 78.13) because of its narrower elec-  tronic collimation [full width half maximum (FWHM) cen-  tral resolution for PET being 6 mm compared with 11 mm  for SPECT] [21, 32, 33]. As the condylar growth plate is  thin, PET gives an advantage to identify pathologies like  condylar hyperplasia.   Important factors to be taken into account when assessing  a bone scan:  ¢ The efficacy of bone scan is reduced during the growing   ¢ The efficacy of bone scan is increased after the growth  phase is completed as only the affected condyles will  show increased metabolic activity.   ¢ The efficacy of bone scan is increased in unilateral cases  and reduced in bilateral cases.   — The growth in type 1 condylar hyperplasia is only  slightly faster than the normal condylar growth rate.  Therefore, the difference in intensity of radiotracer  uptake between a normal and affected condyle is  negligible.   — The cellular growth activity is confined to a narrow  band at the normal growth center resulting in low  uptake of the radiotracer.   — Condylar hyperplasia type 1A cases: It is difficult to  differentiate CH type 1A from normal growth as it a  bilateral condition with both joints involved.   — Condylar hyperplasia type 1B cases: As this is a unilat-  eral condition, it is easy to identify clinically. There  has to be a difference in activity of at least 10%  between the affected side and the normal side for a  diagnosis of asymmetric growth activity/unilateral  condylar involvement to be made.   — Itis easy to diagnose on the bone scan as it is usually a  unilateral condition with a tumorous rate.   — There is diffuse cellular activity throughout the tumor  in the condylar head which makes it easier to diagnose  on the bone scan.    Asymmetries with congenital and developmental etiology are  commonly associated with dental compensations in all three  dimensions as growth ensues. Rotations and crowding are    Fig. 70.16 The flow chart outlines the Boston University Protocol for  the management of temporomandibular disorders in patients who pres-  ent for orthognathic surgery and has been reproduced from the article    seen in hypoplasia cases such as hemifacial microsomia, and  spacing and cross bites can be encountered in case of overde-  velopment such as condylar hyperplasia. Transverse growth  discrepancies also result in different arch shapes and Bolton  discrepancy. Also, the extent of maxillary asymmetry should  be accounted for, as maxilla tends to be ignored in obvious  mandibular asymmetry. Thus, pitch, yaw, and roll need to be    “Nadershah M, Mehra P. Orthognathic Surgery in the Presence of  Temporomandibular Dysfunction. What Happens Next? Oral   (a) The presence of a dental and facial midline mismatch  indicates a discrepancy in the yaw of the affected jaw[s].  Midline correction at the time of orthognathic surgery  provides the best results.    (b) Any occlusal cant correction should not be attempted  orthodontically. Cant is evidently skeletal in nature and  should be corrected surgically.   (c) Levelling and alignment of the dental arches should be  done.   (d) Post-operative position of the upper incisor and the  upper lip-maxillary incisor relationship is the most  important factor determining surgical result. This should  be checked intra-operatively before fixation of the  maxilla.  Position of the symphysis similarly is another important  determinant of a satisfactory postsurgical correction in  cases of asymmetry; thus the anatomical position and  surgical limits of symphysis correction should be deter-  mined pre-surgically.  (f) The facial midline reference should be taken from the  unaffected jaw.  In cases of hemifacial microsomia and temporomandib-  ular joint ankylosis, a unilateral open bite is created after  increasing the ramus height. This is done to correct the  skeletal cant by allowing the vertical alveolar growth of  maxilla.  Cephalometric analyses are essential but seldom defini-  tive in determining the amount of advancement in  antero-posterior and vertical movements. Prediction  tracings are helpful but not mandatory in planning post-  surgical outcome. Specific norms available are not  always applicable especially in asymmetry cases as the  etiology is variable. The etiology and duration of asym-  metry influence the extent and severity of the case.   extraction [minimal decompensation] or upper first  bicuspid extraction [greater decompensation] is  indicated.    Importance of understanding growth of the maxillofacial  skeleton in an individual presenting with asymmetry cannot  be emphasized enough. Almost half of the asymmetries are  either due to an underdevelopment or an overdevelopment of  the TMJ resulting in a deviated mandible in the vertical or  antero-posterior direction or both of the involved side or the  contralateral side. If this development takes place in the  growing period, the maxilla follows the deviation of the  mandible. Interceptive orthodontics can be applied in grow-  ing areas to arrest or limit the extent of asymmetry of the  maxilla and mandible [35]. However, surgical intervention is    generally needed after completion of growth period for the  final skeletal and dental correction. Surgical treatment per-  formed before growth completion is unpredictable on  account of the continual growth that the patient experiences  till skeletal maturity and as such is reserved only for those  cases suffering from extreme functional, aesthetic, and psy-  chological problems. Additional surgery may be needed to  correct the recurrent asymmetry. Thus, timing of surgery  relies very much on the growth completion.   Serial cephalometric radiographs, scintigraphy, and  SPECT scans are useful to assess growth potential. The  absence of activity in the TMJ and other areas helps the sur-  geon to proceed for corrective orthognathic surgery. The sec-  ond factor for determining the timing of treatment is the  progression of the asymmetry. If the asymmetry is progres-  sive like condylar hyperplasia, it is better to wait or perform  high condylectomy to check any further asymmetric growth.  On the contrary, non-progressive asymmetries such as hemi-  facial microsomia, treatment can be initiated in early years  [36]. Comparably, early surgery has usually been performed  for individuals with marked malformations such as plagio-  cephaly, cleft lip and palate, and/or severe functional burden  (e.g., increased intracranial pressure, severe obstructive sleep  apnea, etc.). Lastly, in few cases of acquired asymmetry such  as tumor resection, “wait-and-watch” policy needs to be  adopted to eliminate chances of recurrence before a defini-  tive reconstruction can be planned.    Functional orthopedics play a substantial role in congenital  asymmetries, the greatest example being nasoalveolar molding  in cleft lip and palate cases to bring the maxillary segments into  amore desirable position prior to surgery. Growth modification  with the use of functional appliances is directed toward erup-  tion of the dentition in a more favorable position and prevents  worsening of the skeletal asymmetry exacerbated during  growth period. Functional therapy is also aimed at maintaining  the condyle in a more anatomical position to allow further  growth in a symmetrical pattern. Studies have shown that an  asymmetric lateral force during the growth period results in  growth modification by influencing the morphology of the  mandibular bone and the overlying masseter muscle. Occlusal  splints can be fabricated to allow for mandibular shifts toward  midline, and open bite can be created to eliminate canting. This  is especially helpful in hemifacial microsomia and TMJ anky-  losis cases. Patient compliance is a prerequisite in functional  therapy cases. Also, keeping in view the growth potential, long-  term follow-up is always warranted.    TMJ is the driving force in the development of an asymme-  try. Although the role of condylar cartilage has been proved  to be secondary in mandibular growth and development, any  pathological change leading to under- or overdevelopment  can cause severe progressive asymmetry. As mentioned,  TMJ-related asymmetries can be categorized as underdevel-  opment or overdevelopment of the condyle and in some  cases both. Pseudo-asymmetry occurs due to lateral shifts on  account of dental pre-maturities. Kaban and Pruzanksy have  also graded hemifacial microsomia (Refer Chap. 78) based  on the anatomy of the ramus condyle unit [RCU] and the  glenoid fossa which make up the TMJ [36, 37]. Management  of the TMJ pathology should be performed initially follow-  ing which any skeletal correction should be attempted.  Failure to do so has led to relapse due to the unpredictability  of TMJ behavior and growth. Clinical and diagnostic imag-  ing should be performed prior to any asymmetry correction  to assess the status of TMJ. CT scans are a must for assess-  ment in all three axes, as TMJ tumors like osteochondroma  may not be discernible on 2D imaging. High or low condy-  lectomy, ankylosis release, and RCU reconstruction should  be done prior or simultaneously with orthognathic surgery.  Distraction osteogenesis has also been used for neo-condyle  formation. Alloplastic reconstruction of the TMJ is the most  recent advancement with stable long-term results. The ratio-  nale for TMJ reconstruction is to provide a functional stable  and reproducible movement which is harmonious with the  stomatognathic system. Asymmetrical patients have also  been found to have a higher incidence of condylar morpho-  logical changes and temporomandibular disorders on the  affected side. Over time, due to the imbalance of masticatory  loads and poor jaw function, the TMJ of the unaffected side  also displays similar pathological changes [38].    Following issues need to be considered before planning  orthognathic surgery (Box 70.2):    Box 70.2 Issues that need to be considered before  planning orthognathic surgery    Facial asymmetries are rarely corrected by single jaw surgery.  When the amount of discrepancy is excessive, it is best treated  by dividing the overjet as well as the cant between the two jaws  to achieve optimal results. During growth in congenital and  developmental cases, maxilla follows and is equally involved  as the mandible. Thus, it is prudent to do a bi-jaw surgery. Also,  in cleft maxillary hypoplasia cases, differential maxillary  advancement with simultaneous setback is the treatment of  choice. We have presented a case where simultaneous maxil-  lary distraction was done with mandibular setback. Owing to  the presence of a cleft, maxilla has severely deviated midline  with an extreme reverse overjet. In such cases, maxillary dis-  traction allows slowly advancing the maxilla and simultane-  ously correcting the midline by distracting more on the deficient  side [39] (Fig. 70.17a—c). Segmental osteotomies or differen-  tial surgically assisted rapid palatal expansion (SARPE) might  also be needed in some cases to correct transverse asymmetry  (Fig. 70.18a—c). Additionally, bone contouring of the mandible  and zygoma may be needed to reduce the hyperostotic bone to  achieve a harmonious facial contour. This is true in case of  hemifacial hypertrophy and hemi mandibular hyperplasia.  Similarly, additional augmentation of paranasal areas, malar  prominence, and angle of mandible augmentation are fre-  quently indicated in hypoplasia cases.    Either of the surgical sequences can produce similar out-  comes when properly planned and executed in the vast  majority of bimaxillary cases. Mandible first approach is  specially mentioned here as it is important in Class 3 asym-  metries. Firstly, in cases where maxilla may be hypoplastic,  especially in the syndromic cases of mandibular hyperplasia,  rigid fixation of maxilla and down-grafting may not give  stable results. Thus mandible should be fixed first, then max-  illa. Secondly, because of differential load on the TMJ,  CO-CR discrepancy exists, and it is difficult to achieve a  stable centric. In such cases fixing the mandible first is ben-  eficial [40]. Lastly, Class 3 asymmetries are associated with  concomitant TMJ pathologies, hence TMJ surgeries such as  high condylectomy may be needed to be performed simulta-  neously, in such cases, and mandible first approach is gener-  ally the preferred choice.    The surgery first approach [SFA] came about as there was a  need for immediate aesthetic improvement with shortening    of the overall duration of treatment. However, it should be  known that not all cases fulfil the criteria for SFA [e.g., flat  curve of Spee and minimal crowding and rotations]. The  total treatment duration can be shorter than the conventional  three-staged surgical orthodontic treatment owing to the lack  of need of pre-operative orthodontics and the subsequent  post-surgical “regional acceleratory phenomenon.” However,  reliability of SFA is still questionable, especially in more  complex dentofacial deformities, like facial asymmetry.  Park et al. reported no significant differences in postop-  erative stability between SFA and OFA after bimaxillary sur-  gery in skeletal class III malocclusion patients [41]. In SFA,  vertical dimension in surgical occlusion can increase due to  occlusal interference and lead to postoperative counter    clockwise rotation of the mandible as occlusal settling pro-  gresses during the postoperative orthodontic period. This  may contribute toward greater postoperative mandibular for-  ward movement.    The bilateral sagittal split osteotomy is the commonly used  technique in asymmetry cases. It is highly flexible and adapt-  able in all movements. The three-dimensional anatomy of  the mandible must be retained when planning a  BSSO. According to Schwartz, three types of surgical move-    Fig. 70.17 Case of cleft maxillary hypoplasia who underwent maxillary distraction using internal device. (a) Pre-operative profile photo showing  retruded midface, (b) post-operative profile photo showing good midface fullness, (c) post-distraction lateral cephalogram showing distractor    Fig. 70.18 (a) View of the maxillary study model. (b) Osteotomy cut marked for SARPE. (c) Fixation done using miniplate only on left side. This  is done to ensure expansion of the only the right side on activation of appliance    Fig. 70.19 (a) When an asymmetric case is viewed along the vertical  axis, areas that require immediate bone removal become obvious.  Heavy interferences will take place anteriorly on the long side and pos-  teriorly on the short side; (b) After the condyle is seated, premature  bone contact is noted posteriorly. The area proposed for additional bone    ments can be planned with BSSO in asymmetry cases: in  case of a normal overjet and overbite, differential movements  will be made that is setback on the long side and advance-  ment on the short side. In Class II asymmetry, in order to  achieve symmetrical advancement, there will be a longer  advancement on the short side than on the long side and  lastly in Class III cases, there will be a larger setback on the  long side than on the short side. During surgery, the distal  segment rotates from the short side to the long side as the  midline is corrected (Fig. 70.19a). Selective bone removal  from the area of interferences should be done before the dis-  tal segment has been passively repositioned. Bone is removed  from the anterior and medial aspects of the proximal seg-  ment until there is broad contact along segments. On the  short side, first contact will occur posteriorly [42]. Bone is  removed from the medial aspect of the proximal segment  posteriorly (Fig. 70.19b, c). This is done to reduce condylar  torque during rigid internal fixation to ensure stability of the  movement. Figures 70.20a—d and 70.21a, b show a case of  unilateral condylar elongation treated with differential  BSSO.    removal is indicated by the dotted line; (¢) Good bone contact has been  achieved. Image Source: Schwartz HC. Efficient surgical management  of mandibular asymmetry. J Oral Maxillofac Surg. 2011 Mar;69(3):645—  54. doi: 10.1016/j.joms.2009.03.009. Epub 2010 Oct 8. PubMed PMID:  20934795 [42]    The asymmetrical growth of soft tissues may lead to residual  soft tissue asymmetry even after correction of the underlying  bony deformity. Furthermore, some asymmetrical craniofacial  regions cannot be corrected by means of conventional surgical  techniques. Adjunctive soft tissue procedures [e.g., dermis fat  transplant, autologous fat transfer, microvascular adipose free  flaps] might be indicated to achieve bulk in deficient soft tissue  deformities such as Parry Romberg syndrome, TMJ ankylosis,  etc. Alloplasts such as Medpore, silicone, nanogels, tissue  expander, etc. have also been used with varying degrees of  success (Sect. 70.7 “Case Scenarios”).    Distraction osteogenesis is the process of native bone for-  mation via traction of osteotomized segments. On account  of distraction histogenesis, simultaneous soft tissue and    Fig. 70.20 (a—d) Clinical and radiographic images showing a case of image showing severe facial asymmetry with unilateral condylar elongation  on the right side. (a) frontal photo, (b) profile photo, (c, d) lateral and frontal views on volume rendered 3D CT scan    hard tissue augmentation can be achieved. Adequate  amounts of advancements can be achieved without any  soft tissue limitations. Various cases have been treated suc-  cessfully with DO that are presented in this chapter. DO  has various advantages over conventional osteotomies in  complex facial asymmetries. Pre-arthroplastic distraction  in ankylosis-related asymmetries has been reported to have  excellent results [43]. This is because simultaneous dis-  traction of skin, muscle, and tissue takes place with bone  regeneration. Thus, better esthetics are achieved without  any need for additional soft tissue procedures. Distraction    is often the only procedure of choice in large advance-  ments, rate of relapse is significantly lower, and results are  much stable. Figures 70.22a—e, 70.23a, b, 70.24a—d and  70.25a—g show a case of facial asymmetry secondary cos-  tochondral graft resorption in a case of TMJ ankylosis,  treated with stage one distraction osteogenesis followed by  definitive correction with BSSO.   (Also refer Figs. 78.43, 78.44, 78.45, 78.46, 78.47, 78.48,  78.49, 78.50, 78.51, 78.52, and 78.53 for management of  facial asymmetry cases due to Hemifacial microsomia and  Traecher Collins syndrome).    Fig. 70.21 Same patient as  in Fig. 70.20 demonstrating  corrected facial midline and  mandibular prognathism  postoperatively (a) frontal  view, (b) profile view    Facial asymmetry is a three-dimensional facial deformity hav-  ing multiple etiologies. Complete and thorough knowledge of  the etiological factors, the progressive nature of the asymme-  try plays a crucial role in formulating a treatment plan. Growth  and development of the individual and timing of intervention  is the single most important factor affecting the stability of  results in any form of asymmetry. Severe relapses could occur  if the exact cause of asymmetry is overlooked and treatment is  attempted before completion of growth [44, 45].    Acknowledgment Gratitude and acknowledgments to Dr. Harsh Desai  and Dr. Shibani Nerurkar for their sincere efforts in collection of data  and editing of the contents.    Case 1: Condylar Hyperplasia with  Concomitant Masseteric Hypertrophy (Figs.  70.26a, b, c, 70.27a, b, 70. 28a, b and 70. 29a, b)    A 27-year-old female patient reported with a complaint of a  progressive facial asymmetry and an appearance of fullness  over the left angle of the mandible.    On examination, the patient had a tapered, triangular  shape of the face with an obvious facial asymmetry which  was evident along with elongation of the right side of the  face and fullness over the left angle region (Fig. 70.26a).  The mandible revealed bowing on the right side with a mild  symphysis kink. TMJ on palpation revealed mild clicking  on the right side and otherwise equal movements along  with unrestricted mouth opening was noted. On assessing  the left angle region, an outward projection was noted due  to the underlying hyper functioning of the masseter muscle.  On clenching, significant enlargement of the involved mus-  cle was seen as compared to the contralateral side  (Fig. 70.26b).   Intraoral examination did not reveal any occlusal cant  (Fig. 70.26c). There was an absence of cross bite/open bite,  on either side, along with a stable occlusal relationship. The  dental midlines were coincident with the skeletal midline  and with each other too. No other dental abnormalities were  evident on examination.   Imaging studies revealed mild degree of deflection of the  chin and mandible toward the left side (Fig. 70.27a, b).  Transverse mandibular asymmetry was reported. The condy-  lar head appeared to be irregularly deformed, while the neck  on the right side appeared broader as compared to the left  side. The ascending ramus appeared elongated with a  rounded gonial angle. The mandibular lower border was  bowed downward and positioned lower on the right side as  compared to the left side. The distance between the tooth    Fig.70.22 (a-e) Case of facial asymmetry post-TMJ ankylosis treat- skull view showing asymmetry on the left side with screw from earlier  ment, due to resorption of costochondral graft. Note the exposed screw _costo-chondral graft fixation, (d) photograph showing trans-oral expo-  intraorally. Left side of mandibular arch fully telescoped inside the sure of screw and (e) malocclusion with midline shift to the right, dental  maxilla. (a) basal view showing gross asymmetry, (b) patient retaining | crowding and left sided lingual cross-bite    Fig. 70.23 (a, b) Stage | treatment in the same patient as in Fig. , left side vertical ramus distraction to establish equal ramal height. (a)  Initial height of ramus prior to beginning distraction, (b) vertical lenghtening of ramus after completion of distraction    Fig. 70.24 (a—d) Second stage treatment in same patient as in Fig.  70.22: distractor removal with differential BSSO. (a) intra-operative  photo from stage | surgery, showing osteotomy line for distraction (yel-    roots and mandibular canal was increased with displacement  of the latter towards the lower border of the mandible on the  right side. The right side vertical ramus appeared relatively  increased height as compared to the left. Thickened trabecu-  lar pattern was also evident on the right side.   Following preparation for the administration of GA and a  scintigraphy report which did not reveal an active mandibu-  lar hyperplastic condyle on the right side, the patient was    low arrow), (b) intra-operative photo during distractor removal demon-  strating new bone formation(yellow arrow), (c, d) intra-operative  photos showing osteotomy cuts for BSSO    prepared to be taken up for the procedure of an intraoral  inferior border osteotomy. An intraoral vestibular incision  was taken from 33 regions up to the external oblique ridge  on the right side. Complete degloving was done to expose  the inferior border in the anterior, body, and angle region of  the mandible on the right side. Care was taken to identify  the mental foramen and salvage the nerve. Methylene blue  ink was used to mark the osteotomy line extending from the  right central incisor posteriorly up to the angle region  (Fig. 70.28a). It was correlated with the position of the neu-    Fig. 70.25 (a—g) Pre- and postoperative photographs of the same  patient as in Fig. 70.22, showing restoration of symmetry and midline  (a, b) pre and post-operative frontal photographs showing correction of  asymmetery, (c, d) pre and post-operative profile photographs demon-  strating increased vertical height of ramus, (e) pre-treatment intra oral    rovascular bundle, so as to prevent any damage to the same.  The cut was initiated with a fine fissure bur under copious  saline irrigation extending from buccal cortical plate to lin-  gual cortical plate. With the help of an osteotome, the ante-  rior cut was completed, and the lower inferior hyperplastic  border was removed in one piece (Fig. 70.28b). The raw  surface was smoothened with a vulcanite bur, and contour-  ing was done to match the normal left side. The wound was  closed in two layers with interrupted sutures using 3-0 vic-  ryl. The surgical site was flushed with 2% povidone iodine  solution.    occlusion demosntrating severe shift in the dental midline with lingual  crossbite on the left side, (f) orthodontic strap-up for dental and arch  alignment, (g) post-treatment occlusion showing good dental  rehabilitation    For the masseteric hypertrophy on the left side, Botox  [botulinum toxin Type A, Allergan™] powder was reconsti-  tuted with normal saline solution, pushed within the vial, and  30 units of it were administered using an insulin syringe and  30 gauge needle within the substance of the muscle, divided  equally at three sites in a triangular fashion (Refer Chap. 33  and Fig. 33.10 for details on Botox injection to treat masse-  teric hypertrophy).   Complete correction of facial asymmetry with left side mas-  seteric hypertrophy and right side condylar hyperplasia fea-  tures was achieved with this surgical method (Fig. 70.29a, b).    Fig. 70.26 (a, b) Frontal and profile views showing facial asymmetry due to condylar hyperplasia of the right side. (c) Occlusal view showing    Case 2: Parry Romberg Syndrome (Figs. 70.30a,  b, 70.31a, b, 70.32a, b, c, 70.33a—-h and 70.34a-f)    An 18-year-old female patient reported with gradual disfig-  urement and shrinkage of the right side her face since last  8-9 years.   Clinical examination revealed an asymmetry of the  face on the right side with a marked atrophy of facial soft  tissue (Fig. 70.30a). Significant orbital dystopia along  with a hypoplastic soft tissues in the right, evident on  worm’s view (Fig. 70.30b). Clinically, a deformed and    hypoplastic upper lip was seen with an increased vermil-  lion show of the lower lip, resulting in a slanting rima  oris. The right commissure, right ala of the nose, and  the right supraorbital ridge region revealed obvious  depression.   Intraoral examination revealed a missing upper right per-  manent canine along with crowding in the premolar region.  Alveolar height in the maxillary right premolar region was  reduced which was a pathognomonic sign of Parry Romberg  (Fig. 70.31a, b). The occlusion was deranged, with a shift of  the dental midline to the right.    Fig. 70.27 (a) PA mandible showing inferior border bowing on the right side and kink in chin region (yellow arrows) which stops at the midline.  (b) 3D CT shows mild degree of tilting of chin and mandible toward the left side    Fig. 70.28 (a, b) Inferior border osteotomy to remove the excessive contour below the mental nerve    Fig. 70.29 (a) Pre- and (b) post-op correction in facial asymmetry. Reduction of fullness on left side and centralization of chin    Imaging studies revealed some degree of hypoplasia of  mandible, zygoma, and maxilla on the right side. Presence of  impacted permanent right maxillary canine was evident. The  body-angle ramus, coronoid, and condylar process however  appeared normal. Alveolar height was reduced in the right  maxillary premolar region (Fig. 70.32a, b, c).   The patient was prepared for GA administration for correction  of facial asymmetry. A camouflage technique was planned  wherein multiple Medpore© implants were used to fill up the  deficient areas on the right side of her face in the right supra-  orbital, right maxillary alveolar region in the canine, and pre-  molar areas right parasymphysis region of the body of  mandible and right side chin along with autologous lipo trans-  fer to increase the volume of the upper lip. Two separate small  incisions were taken in the submandibular region anteriorly  and posteriorly keeping the intervening skin and tissues intact.  Layerwise dissection was done to reach the angle, body, and  the anterior regions of the mandible. Tunnelling was done  between the two incisions so as to receive the pre-shaped  Medpore© implant, which was inserted from the anterior site  and was pushed posteriorly to sit on the body, angle, and a por-  tion of the ramus. The implant was notched in the superior  aspect, in the region of the mental nerve to prevent impinge-  ment of the same. Four long titanium screws were used to fix    the Medpore© implant on the body of the mandible on the  right side (Fig. 70.33a). An additional half chin implant was  placed to augment the deficient chin on the right side for  achieving symmetry and was fixed with 2 long titanium screws  (Fig. 70.33b). The incision sites were closed in two layers.   Another lateral eyebrow incision was taken on the right  side (Fig. 70.33e). Dissection was done to expose the supra-  orbital rim. Supraorbital foramen and nerve were identified.  An infra-orbital rim Medpore© implant for the right side  was inverted and placed on the right supraorbital region to  augment this deficient area. Two long titanium screws were  used to stabilize the Medpore© implants.   Intra-orally a vestibular incision was taken in the right  premolar and canine region. A full-thickness mucoperiosteal  flap was raised. The infra-orbital nerve was identified and  protected. A paranasal Medpore© implant was fixed with 1  long titanium screw to give fullness in this region. The  wound was sutured in two layers with 3-0 vicryl.   Periumbilical and medial thigh regions were prepared to  harvest fat cells. Manual aspiration of the fat cells was done.  Following the simple method of sedimentation, the fat cells  were separated from the blood components (Fig. 70.33f). 2 mm  incisions were taken on either side of the oral commissure. A  large 16 gauge epidural needle attached to 10cc syringe was  used to push the fat within the substance of the upper lip from  either side (more on right side than on the left) increasing the    Fig. 70.30 (a) Frontal view—right side reveals marked atrophy in the distribution of all three branches of trigeminal nerve. (b) Asymmetry of the  inferior border evident on worm’s-view involving soft and hard tissue    Fig. 70.31 (a, b) Intraoral examination of the same patient as in Fig. 70.30, reveals reduced alveolar height (blue arrow) in the right premolar  region (a), as compared to the left side (b). Alveolar height reduction is an important clinical finding in Romberg’s disease    Fig. 70.32 (a,b) 3D CT of the patient in Fig. 70.30 reveals skeletal deficiency of alveolar height on right side (blue arrow), and reduction in verti-  cal height of the ramus and body of the mandible on right side, (c) left side shows normal anatomy    Fig. 70.33 (a) Extra-oral incisions—submandibular incisions made  anteriorly and posteriorly. Medpore implant in ramus and body fixed  with four titanium screws. (b) Additional half chin implant fixed with  two titanium screws on right side of chin region. (c) Paranasal and alve-  olar Medpore implant fixed through intra-oral approach with titanium  screws. Infraorbital nerve protected. (d, e) Use of Medpore implant for    volume of upper lip (Fig. 70.33g). A stitch on either side of the  commissure was taken to prevent escape of fat cells  (Fig. 70.33h). Overcorrection was done on_ table.  Postoperatively, good facial symmetry was achieved with full-  ness at the deficient site using fat and implant (Fig. 70.34a-—f).    right side supra orbital rim. Notch placed superiorly to protect the  supraorbital nerve. (f) Sedimentation to separate fat cells from blood  components. Harvesting autologous fat grafts. (g) Introduction of fat  cells into the upper lip through needle prick in right commissure. (h)  Overcorrection achieved on table    For further case scenarios on management of facial  asymmetry refer Figs. 68.19 and 68.38, in Chap. 68 on  mandibular orthognathic procedures and Figs. 69.30, 69.31,  69.32 and 69.40 in Chap. 69 on maxillary orthognathic  procedures.    Fig. 70.34 (a—f) Comparison  of pre and post op results after  4 years. Satisfactory  correction in facial  asymmetry achieved. 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Am J  Orthod Dentofac Orthop. 2001;119(2):95-101.   45. Wolford LM, Karras SC, Mehra P. Considerations for orthognathic  surgery during growth, part 2: maxillary deformities. Am J Orthod  Dentofac Orthop. 2001;119(2):102-5.    Grummons DC, Kappeyne van de Coppello MA. A frontal asym-  metry analysis. Journal of Clinical Orthodontics: JCO.  1987;21(7):448-465.    Open Access This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.  org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropri-  ate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.   The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in  a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.   Obstructive sleep apnea (OSA) is a condition that affects  2-4% of the adult population. This disease has reached a  proportion of increasing importance due to its neurological  and cardiological consequences. Abnormal pharyngeal anat-  omy and altered activity of the upper airway musculature  dilator physiology are primarily responsible for the collapse  of the pharyngeal walls during sleep.    OSA is defined by the occurrence of daytime sleepiness,  loud snoring, witnessed breathing interruptions, or awaken-  ings due to gasping or choking in the presence of at least five  obstructive respiratory events (apneas, hypopneas, or respi-  ratory effort-related arousals) per hour of sleep [1].   When OSA is accompanied by excessive daytime sleepi-  ness, it is termed Obstructive Sleep Apnea Syndorme.   The common terms that are used in OSA are apnea,  hypopnea, apnea hypopnea index (AHI), and respiratory dis-  tress index (RDJ) [2].   2. A hypopnea is reduced airflow exceeding 10 seconds  accompanied by a desaturation of 3% or more of oxygen  and/or electroencephalographic evidence of arousal.   3. The apnea hypopnea index (AHI) is the number of apneas  and hypopneas per hour of sleep. A value of 5—15 repre-  sents mild sleep apnea, 15-30 moderate, and greater than  30, severe.   4. Respiratory distress index (RDI) includes other parame-  ters in addition to apnea and hypopnea like respiratory  effort-related arousals (RERAs). This is characterized by    S. Menon (4)  Department of Oral and Maxillofacial Surgery, Vydehi Institute of  Dental Sciences and Research Centre, Bangalore, India    © The Association of Oral and Maxillofacial Surgeons of India 2021    increasing respiratory effort for 10 or more seconds lead-  ing to an arousal from sleep but not meeting the criteria of  an apnea or hypopnea [3].    The upper airway is a flexible structure consisting of muscle  and fat tissue and is usually only passively supported by  bones. Therefore, it can be easily influenced by soft tissue  factors like fat deposition in the parapharyngeal structures,  edema/inflammation of the parapharyngeal region, hypertro-  phy of adenotonsillar tissues, or enlarged tongue.   The primary actor in the pathophysiology of OSA is the  narrow, floppy upper airway. There is increased resistance of  the upper airway due to anatomic factors that creates a nega-  tive airway pressure. This results in impaired function of  airway-dilating muscles, thus increasing collapsibility.  During sleep, the loss of skeletal muscle tone narrows the  upper airway, making it floppier, especially during rapid eye  movement (REM) sleep when muscle relaxation is intense.  This results in two significant actions:    ¢ The turbulent flow patterns that occur lead to vibration of  structures causing snoring.   e The pharynx collapses due to the Bernoulli effect. This  causes an obstruction which could be partial or complete.  This tends to persist until sleep is interrupted and muscle  tone is restored. These interruptions usually last less than  15 seconds, and the individual is unaware of them.  Sometimes, the obstruction results in an awakening, and  the individual complains of suddenly waking with a snort  or a snore. Breathing is reestablished on arousal, and after  a few breaths deeper sleep resumes with repetition of the  cycle during muscle relaxation.    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1-15-1346-6_71    Additional factors that can increase the severity of upper  airway resistance during sleep are mouth opening or a supine  posture which allows the gravitational forces to push the  tongue and soft palate back. Upper airway resistance can  occur anywhere from the nasopharynx to the hypopharynx  but primarily involves the oropharynx (Fig. 71.1).    The disease prevalence increases steadily with age and  reaches a stable level after the age of 60 years. The probable  explanations for the age-related increase in prevalence  include increased fat deposition in the parapharyngeal area,  soft palate lengthening, etc.    Body weight is an important risk factor for OSA, and studies  have endorsed the positive effects of dieting and surgical  weight loss on reducing OSA. Body weight increase can  affect normal upper airway mechanics during sleep through:    It is an established fact that men are more vulnerable than  women toward developing OSA. The differences exist not  only in prevalence but also in polysomnographic characteris-  tics of sleep and breathing patterns. Women were seen to  have a lower AHI in non-rapid eye movement (non-REM)  sleep. Disordered breathing events in women have a shorter  duration and are associated with less oxyhemoglobin desatu-  ration than in men.    The mechanical properties of the upper airway and the ten-  dency to collapse during sleep can be influenced by both  hard and soft tissues in the region. Findings in the craniofa-  cial region like large tongue or soft palate, reduced mandibu-  lar size, or tonsillar hypertrophy in addition to inferiorly  placed hyoid, maxillary, and mandibular retropositioning  can narrow upper airway dimensions and leading to episodes  of apneas and hypopneas during sleep.    Inheritance and familial factors also play a major role in  OSA. First-degree relatives of OSA patients seem to be at  risk more likely than others. The familial susceptibility tends  to increase directly with the number of affected relatives.  Heredity and genetic factors also have been found to have  arole in determining the volume of the lateral parapharyngeal    walls, tongue, and total soft tissue structures. A detailed fam-  ily history can help in identifying those that have the disorder  but remain undiagnosed.    Cigarette smoking and alcohol are also possible risk factors  for obstructive sleep apnea. Airway inflammation can occur  due to cigarette smoke that could modify the properties of  upper airway and increase its collapsibility during sleep.  Alcohol consumption before sleep increases upper airway  collapsibility and the precipitate apneic and hypopneic epi-  sodes during sleep. Another effect of alcohol is to inhibit  respiratory motor output to the upper airway, causing hypo-  tonia of the oropharyngeal muscles.    There is enough evidence to suggest that OSA can be a factor  in the development of hypertension, coronary artery disease,  congestive heart failure, and stroke [4].   OSA is also associated with diabetes mellitus, Therefore,  diagnosing the condition and intervening early could directly  or indirectly enhance glycemic control [5]. The role of posi-  tive airway pressure (PAP) therapy could result in reduced  day time fatigue, better physical activity, resulting in  improved metabolic control.    The central effects of sleep fragmentation and hypoxemia  have been seen to induce a reversible neuroendocrine defect in  growth hormone and testosterone secretion. This may explain  impaired growth seen in children with upper airway obstruc-  tion which seems to get better after adenotonsillectomy.    The classic feature of OSA prevalent as excessive daytime  sleepiness may lead to both impaired work performance and  driving. OSA patients seem to perform poorly on psycho-  metric tests, and improvement has been seen after nasal  CPAP therapy.    There are two serious consequences of OSA involving the  cardiovascular system. Initially acute cardiovascular changes  occur during an apnea. This is followed by more chronic car-  diovascular conditions like hypertension, myocardial infarc-  tion, stroke, and death.    OSA has no specific age predilections, but a study by Young  et al. estimated the prevalence in middle age to be 4% for  men and 2% for women. Their study estimated that 1 of  every 5 adults has at least mild OSA and | of every 15 has at  least moderate OSA.    A detailed study of clinical signs and symptoms established  during a comprehensive sleep evaluation and findings identi-  fied by sleep testing lead to the diagnosis of OSA.    The diagnosis of OSA begins with a sleep history in one of  three settings:   3. Part of the comprehensive evaluation of patients at high  risk for OSA.    Of the available, the Epworth sleepiness scale (ESS)  (Table 71.1) is a popular subjective-based self-assessment of  sleepiness that determines the degrees of sleepiness [9].  When scores are greater than 10, further investigations are  recommended. However as about 10% of the population  have a score of 11 or more, this score should be comple-  mented by a narrative confirmation of intrusive somnolence.    This is an overnight sleep study monitored by a sleep  technologist and is considered the “gold standard” in  sleep medicine (Fig. 71.2). The physiologic parameters  measured during PSG include simultaneous monitoring of    Name: Date:  Age: Sex:  How likely are you to doze off or fall asleep in the following  situations, in contrast to feeling just tired?  Use the following scale to choose the most appropriate number for  each situation:  0—Would never doze  1—Slight chance of dozing  2—Moderate chance of dozing  3—High chance of dozing  Situation Chance of  dozing (0-3)  1.Sittngandreading, 2 wenn ==   4. As a passenger in a car for an hour without  break.   5. Lying down to rest in the afternoon when  circumstances permit.   8. In a car, while stopped for a few minutes in  traffic.    brain wave activity continuously, eye movements, muscle  activity of the legs and mandible, body position, heart rate  and rhythm, blood pressure, snoring, and respiratory  activity including breathing patterns and oxygen satura-  tion. A detailed analysis of these can reveal apneic, hypop-  neic activities, etc.   Presence of obesity or signs of upper airway narrowing  should also be documented.    Patients at High Risk for OSA and Who all should be  evaluated for OSA Symptoms [1]    OSA Symptoms That Should Be Evaluated During a  Comprehensive Sleep Evaluation   There is a plethora of imaging aids to help diagnose and plan  the management of OSA. Cephalometrics has been the old-  est imaging modality in the diagnosis of OSA. However, its  role in quantification of the pharyngeal volume is controver-  sial as the image that is two-dimensional is used to evaluate  a three-dimensional structure [3].   It is a known fact that the lateral pharyngeal wall collapse  has a bigger influence on severe sleep apnea than retropalatal  and retrolingual collapse as studied with dynamic MRI, and  this would not appear evident on a lateral cephalogram [10].  Another shortcoming of lateral cephalograms is that they are  taken with the patient upright and awake and therefore do not  characterize the asleep or supine airway.   Cephalometric images however have other advantages  that can be used to predict OSA. It can be used to measure  the upper airway length (UAL) (Fig. 71.3). UAL is signifi-  cantly longer in OSA patients due to the relation between  UAL and airflow resistance. Since the part of the airway is  primarily composed of the soft tissues compared to the more  rigid, cartilaginous, subglottic airway, this region may pre-  dispose to collapse. Studies have proved that male patients  with UAL > 72 mm have an eightfold increase in the proba-  bility of OSA while females with UAL > 62 mm have a five-  fold increase in OSA probability [11].    Fig. 71.2 Polysomnography leads and parameters. EEG Electroencephalogram, EOG Electrooculography, EMG Electromyography, ECG    Cephalometrics can also be used to predict the success in  multilevel phase I therapy for patients. Skeletal class II  patients with a more retrognathic mandible are poor respond-  ers. Other patients who could be poor responders include  those with hyperdivergent vertical pattern with a larger man-  dibular plane angle, longer lower facial height, and steeper  occlusal plane [9].   Dynamically assessment of the level of upper airway obstruc-  tion in OSA patients will allow targeted intervention and  allow planning a specific surgical procedure by allowing a  delineation of the site and specifying degree and pattern of  obstruction. It can also be used to exclude pathology like    tumors. Dynamic sleep MRI and drug-induced sleep CT  scan characterize the airway in OSA with the advantage of  ability to evaluate the airway in a multiplane fashion in the  sleeping state or a simulated sleep state.   Drug-induced sleep endoscopy (DISE) is an alternative to  conventional endoscopy with the goal of more accurately  representing patterns of collapse during the sleeping state.   In this test, sound waves are projected into the airway and are  reflected into the tube to a computer which creates an image  that determines the location of obstruction. This can also pre-  dict the effect of mandibular advancement and protrusion on  upper airway.    OSA is a chronic condition that would require multidisci-  plinary management over a long period of time. There is a  myriad of options to treat the condition ranging from behav-  ioral to medical to surgical options. The success of treatment  would have to ensure the voluntary active participation of the  patient.    Continuous positive airway pressure (CPAP) is usually the  first line of treatment for OSA. It works on the principle of  binding the upper airway in an open position to improve  patency during sleep (Fig. 71.4).   This was first described by Sullivan [14] in 1981. The  pneumatic splinting action is effective in reducing the  AHI. PAP may be delivered in either continuous (CPAP),  bilevel (BPAP), or auto titrating (APAP) modes. CPAP is the  first line of treatment for moderate to severe OSA and may  be used occasionally in mild OSA. CPAP has also found to  be effective as an adjunctive therapy to alter blood pressure  in OSA patients having hypertension.   Some of these patients may elicit intolerance for CPAP  therapy. In these cases, BPAP, pressure relief, or APAP can  be considered as an alternative. In addition to its splinting    Delirium Frequent coughs/colds  Gastroesophageal reflux  Mood/personality changes  Nocturnal sweating  Restlessness during sleep  Nocturia    action, CPAP increases vagal tone, cardiac output, and stroke  volume and decreases systemic vascular resistance, and there  is reduced risk of cardiovascular mortality.   89% [15]. Reasons for noncompliance are usually due to tol-  erance problems like dry mouth, conjunctivitis, rhinorrhea,  skin irritation, pressure sores, nasal congestion, and epi-  staxis. Other less common causes of noncompliance include  aerophagia, chest discomfort, and bed partner intolerance or  psychological problems arising from lack of motivation,  claustrophobia, and anxiety.  Though there is no established known lower limit of nightly  use below which nCPAP therapy is ineffective, it is sug-  gested that 3.4 h per night of nCPAP use may be adequate to  improve cognitive function and quality of life.    Behavioral strategies have also been used as treatment meth-  ods in OSA. These include weight loss, regular exercise,  positional therapy, and sleep hygiene which involves alcohol  abstinence and consumption of sedatives before sleep.   Sleep position while supine can decrease the lateral upper  airway dimensions, particularly while in the supine position.    Therefore, in positional therapy, the patient is kept in a non-  supine position.    The primary role of oral appliances (OAs) is to enlarge the  posterior oropharyngeal airway space, leading to reduction  of chances of the upper airway collapsing during sleep. They  are ideally indicated in mild and moderate cases of OSA who  are noncompliant/poorly compliant to nasal CPAP. Oral  appliances are of two types: tongue retaining or mandibular  repositioning.    ¢ Tongue retaining devices [18]: These appliances position  the tongue anteriorly by means of negative pressure and  are indicated for patients who have few teeth or are eden-  tulous, have macroglossia, or who are unable to ade-  quately advance their mandible. The result is increase of  the volume of the upper airway.   ¢ Mandibular repositioning devices (MRD) [19]: As the  name suggests, they reposition the mandible and struc-  tures attached to it like the tongue and hyoid bone anteri-  orly, thus increasing the upper airway dimensions in both  sagittal and transverse planes, especially at the level of the  velopharynx (Fig. 71.5). The appliances completely cover  the maxillary and mandibular dentition and hold the man-  dible forward with respect to the resting position. The  amount of advancement is titrated depending on the  symptoms not exceeding 80% of the patient’s maximum    protrusive capacity. This is followed by polysomnogra-  phy to check the efficacy.    It is mandatory for patients using MRD to have adequate  number of teeth to seat the appliance. There should not be  any deleterious TMJ disorder, and the patients should have  an adequate range of jaw motion and adequate manual dex-  terity and should be motivated to use the appliance.   flexible polyamide.  In general, OAs are either titratable or non-titratable.  Titratable OAs permit varying amounts of mandibular pro-  trusion. Non-titratable OAs hold the mandible in a single  protrusive position without any possibility to change the  position during treatment. Some of the non-titratable devices  are a simple splint, bionator, Karwatsky activator, or Herbst  appliance [20].    Surgical procedures to correct or treat OSA essentially pro-  vide site-specific treatment to increase airway size and  decrease airway resistance, thus reducing the effort required  in breathing. The site of obstruction is specific to each patient  and is as unique as fingerprints. Therefore, one needs to  know which the most appropriate procedure is to guarantee  success. Since no single factor is predictive of OSA, the sig-  nificance of a thorough physical examination and imaging to    During sleep there is restricted  airway space  @©Association of Oral and Maxillofacial Surgeons of India   Nasal polypectomy  Endoscopic procedures  uvulopalatopharyngoplasty  Palatal advancement  pharyngoplasty  Tonsillectomy/adenoidectomy  Tori mandibularis excision  Tongue reduction    identify the target site of airway resistance cannot be over  emphasized.   Tracheostomy has been used to bypasses the upper airway  and is thus a successful modality in treatment, but the mor-  bidity associated with it limits its application.   Factors in the nasal cavity may also play a role in influ-  encing the pharyngeal stability through abnormalities like  septal deviation and inferior turbinate. Nasal surgery to  remove these abnormalities can improve nasal airflow, thus  having a positive effect on OSA.   Multiple surgical procedures of the palate like uvulopala-  topharyngoplasty (UPPP), which involves removal of the  tonsils, uvula, and posterior velum in patients with large ton-  sils and relatively normal palatal position, are also good  adjunctive procedures.   UPPP can also be done assisted by lasers allowing more  precise incision and excision than conventional surgery. It  also has the advantages of avoiding the need for general  anesthesia and with minimal bleeding.   Tonsillectomy with adenoidectomy is the usually first line  of surgery for children with OSA without significant cranio-  facial anomalies.    Tongue reduction is also a part of the surgical option in  enlarges tongue cases where partial glossectomy can reduce  the tongue volume.   Surgical procedures of the genial segment of the mandi-  ble like Genioglossal advancement moves the genial tuber-  cles forward along with the genioglossus muscle, resulting in  a more forwardly positioned base of tongue. In addition, it  also causes the forward movement of the hyoid bone. This  shift increases the posterior airway space and avoids the col-  lapse of its walls during the REM phase of sleep. There are a  lot of modifications of the genial advancement procedures.   The standard procedure moves the whole genial segment  including the chin. A modified technique allows the surgeon to  advance the genial tubercle without altering the normal ana-  tomic position or shape of a patient’s chin by only moving the  rectangular bony component involving the tubercle (Fig. 71.6).   Hyoid myotomy involves the detachment of infrahyoid  muscles and moving the hyoid forward and upward and fix-  ing it with sutures. Another procedure moves the hyoid for-  ward and downward with excision of the lesser cornu and  fixing the hyoid anterior to the thyroid cartilage by sutures.   Surgical procedures can also be performed at different  levels either concomitantly or in a staged manner. This is  done when patients have more than one site of obstruction.   Hypoglossal nerve stimulators (HGNS) are a new addi-  tion to the armamentarium for treatment of OSA. It was  approved by the FDA for treatment of moderate to severe  OSA in 2014 [22].    The device which acts like a pacemaker monitors the  breathing patterns and gets activated during sleep to stimu-  late the hypoglossal nerve, thus controlling upper airway  muscles.   Maxillomandibular advancement (MMA) is undoubtedly  the most successful surgical technique in OSA. This advan-  tage of this procedure is the effect in correcting airway  obstruction at multiple levels. The surgical advancement of  the maxillomandibular skeletal framework corrects the air-  way collapsibility at the nasopharyngeal and oropharyngeal  levels and is ideal in patients with moderate and severe OSA  who exhibit multilevel obstruction.   The Le Fort I osteotomy of the maxilla along with mandibu-  lar sagittal split osteotomy is performed for advancing maxilla  and mandible, thus increasing the airway space as it draws the  base of the tongue and soft palate forwards (Fig. 71.7).   technique, especially in cases of TMJ ankylosis (Figs. 71.8  and 71.9) where a deficient mandible in the sagittal plane is  primarily responsible for the obstructed airway.  The dimensions of maxilla and mandible can also be  increased in the transverse plane by distraction resulting in  increase in the dimensions of nasopharynx, oropharynx, and  the nasal cavity along with movement of tonsillar pillars and  the musculature of the velum. Maxillomandibular transverse  distraction osteogenesis can be concomitantly be performed  with their sagittal advancement for a more effective form of  treatment MMA alone.    Weight loss procedures through bariatric surgery is indicated  in patients with a body mass index (BMI) > 40 kg/m? or  those with a BMI > 35 kg/m? with important comorbidities  especially when dietary attempts are ineffective.    Pharmacologic agents can on occasion be used with some  degree of success in treating OSA by increasing glossopha-  ryngeal neurologic activity or decreasing REM sleep.   Protriptyline, a tricyclic antidepressant reduces the fre-  quency of apnea and desaturation in non-REM sleep and  suppressing REM activity. It also increases the tone of the  upper airway muscles. The anticholinergic activity of the  drug however limits its use.    Fig. 71.9 Improved airway after mandibular distraction in a TMJ  ankylosis case    Theophylline reduces the episodes of apneas and hypop-  neas, but the quality of sleep deteriorates.   Modafinil is a wake-promoting medication that can  improve residual daytime sleepiness in OSA patients despite  regular use of CPAP. It is however avoided in patients who  are noncompliant with CPAP. The adverse effects of these  drugs are headache and nervousness.   Topical nasal corticosteroids have also been recom-  mended in patients suffering from concurrent rhinitis.    Obstructive sleep apnea is a multi-factorial and multi-level  condition whose management needs to be customized for  every patient after a correct diagnosis. Treatment is regulated  starting with the non-surgical options and moving to specific  site surgical procedures depending on the area of  involvement.    A 12-year-old female patient with history of sleeping diffi-  culty due to airway obstruction.   Clinical features: Retruded chin, incompetent lips, dry  mouth, short chin throat distance (Fig. 71.10).   Preoperative radiographic findings: Deficient mandible,  posteriorly placed menton, narrowed oropharynx (Fig. 71.11).    PSG report: Episodes of 33 apneas and 76 hypopneas  confirming OSA (Box 71.1).   Treatment plan: Mandibular advancement of 10 mm by  distraction (Fig. 71.12).   Post op findings: Improved profile, no episodes of apneas  hypopneas (Figs. 71.13, 71.14 and Box 71.2).    Epstein LJ, Kristo D, Strollo PJ, Friedman N, Malhotra A, Patil SP,  et al. Clinical guideline for the evaluation, management and long-  term care of obstructive sleep apnea in adults. J Clin Sleep Med.  2009 Jun 15;5(3):263-76.    . Susarla SM, Thomas RJ, Abramson ZR, Kaban LB. Biomechanics of    the upper airway: changing concepts in the pathogenesis of obstruc-  tive sleep apnea. Int J Oral Maxillofac Surg. 2010;39:1149-S9.    . Carolyn C, Brookes D, Boyd SB. Controversies in obstructive sleep    R, Javaheri S, et al. Sleep apnea types, mechanisms, and clini-  cal cardiovascular consequences. J Am Coll Cardiol. 2017;69(7):  841-58.    olism: it’s all about CPAP adherence! J Clin Sleep Med. 2017 Mar  15;13(3):365-7.    . Yee B, Liu P, Phillips C, Grunstein R. Neuroendocrine changes in    . 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Dicus Brookes, Scott B. Boyd: Controversies in Obstructive  Sleep Apnea Surgery. Oral Maxillofacial Surg Clin N Am 29 (2017)  503-513.   Kasey K Li: Maxillomandibular advancement for Obstructive Sleep  Apnea. J Oral Maxillofac Surg 69:687-694, 2011.   Lawrence J. Epstein, David Kristo, Patrick J. Strollo, Norman Friedman,  Atul Malhotra, Susheel P. Patil et al. Clinical Guideline for the  Evaluation, Management and Long-term Care of Obstructive Sleep  Apnea in Adults. J Clin Sleep Med. 2009 Jun 15; 5(3): 263-276.    Open Access This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.  org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropri-  ate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.   The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in  a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.    Pritham N. Shetty, Jaideep Singh Chauhan,  Mamatha Patil, Neha Aggarwal, and Dipesh Rao   A cleft lip [CL] is defined as a congenital defect in lip conti-  nuity due to an embryological malformation. Cleft lip and  palate [CLP] have an overall incidence of 1 in 1000 live  births [1]. For different ethnicities, the incidence varies. Like  other facial deformities, cleft lip and palate produce a con-  siderable degree of disfigurement and functional impair-  ment. A comprehensive treatment involving a cleft surgeon,  otolaryngologist, geneticist, speech pathologist, orthodontist  and others are required at multiple stages right from infancy  to adulthood. A successful lip repair requires careful consid-  eration of presentation of the cleft, the availability of tissues  or the lack thereof and effect of intervention on growth and  function. We have tried to simplify this concept, keeping cer-  tain key points in mind necessary for comprehension of the  subject. In this chapter, we have discussed embryology, anat-  omy and clinical presentation of cleft as an integrated phe-  nomenon for better understanding of cleft lip. The author’s  technique of cleft lip is discussed in a stepwise manner.    Electronic Supplementary Material The online version of this chap-  ter (https://doi.org/10.1007/978-98 1-15-1346-6_72) contains supple-  mentary material, which is available to authorized users.    P.N. Shetty (2x!)  OMFS, Bangalore Institute of Dental Science, Bangalore, India    J. S. Chauhan  Department of Maxillofacial Surgery and the Smile Train, CHL  Hospital, Indore, India    N. Aggarwal  Cleft and Craniofacial Surgery, Meenakshi Cleft and Craniofacial  Centre, Chennai, India    © The Association of Oral and Maxillofacial Surgeons of India 2021    The enigma of cleft lip and the historic journey to repair the  defect has been well described in the narrative book by Millard  [2].The excerpts from it illustrates the documentation of the first  cleft lip repair in the year 390 AD where an unidentified Chinese  physician cut the edges of the cleft and stitched it together with  a postoperative order of limited lip movements for the next  100 days. The need to identify an ideal technique was derived  on the basis of the anatomical outcome of the repair and also the  postoperative scarring. The concepts of cleft lip repair have  evolved from straight line repairs to a variety of techniques  using various cutbacks, triangles, z-plasties and other flaps.    The techniques for cleft lip can be broadly classi-  fied into:    We will discuss certain techniques to explain the evolu-  tion from a historical point of view. The rotation-advancement  technique with its modifications will be discussed later in  this chapter.    The face is derived from two sources: the frontonasal process  that covers the forebrain (neural crest origin) and the tissues of  first pharyngeal arch (mixed mesoderm and neural crest ori-  gin). These tissues surround the oropharyngeal membrane.  From the frontonasal process, two medial nasal processes and  lateral nasal processes arise [3]. The first pharyngeal arch gives    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1-15-1346-6_72    rise to a pair of mandibular processes and a pair of maxillary  processes from which palatal processes arise [3]. The maxillary  prominences continue to grow medially, compressing the  medial nasal prominences towards the midline, subsequently  meeting the lateral nasal processes and then the lower part of  the medial nasal processes (Figs. 72.1, 77.1). This lower part is  known as the globular or premaxillary process. The compo-  nents derived from various parts are given in Table 72.1.   Abnormalities throughout this complicated developmental  process occur in the most severe congenital forms if they  develop early in facial embryogenesis (4-8 weeks) to the rela-  tively minor problems developing later (8-12 weeks). Cleft lip  varies from a notch in lips red border to extending into the  floor of nostril and the alveolar ridge. It may be unilateral or  bilateral (Fig. 72.2). Some other forms of facial clefts have  also been described in a pictorial form as a result of failure of  fusion of the same processes but in a different trajectory and  various permutations and combinations (Fig. 72.3).    c  Lateral nasal prominence  Nasolacrimal groove  Eye  Maxillary prominence  Medial nasal prominence  Mandibular prominence    Fig. 72.1 (a—d) Development of the face. (a) Lateral nasal and medial  nasal swellings that surround the nasal placodes appear on the frontona-  sal process (b) Paired maxillary processes grow medially, compressing    1. Unilateral cleft lip—due to the failure of the maxillary  prominence to join with the merged median nasal promi-  nences which results in a cleft.   2. Bilateral cleft lip—due to failure of fusion of the maxil-  lary prominences with merged nasal prominences bilater-  ally. The extent of clefting may or may not be similar on  both sides.   Frontonasal The forehead, the bridge of nose,  median and lateral nasal processes    tip of the nose  Alae of the nose  Lateral portion of the upper lip    the medial nasal prominences towards the midline. (c) Medial nasal  processes fuse with each other, lateral nasal processes and the maxillary  processes. (d) Complete development of the nose and upper lip    Fig. 72.2 Relation of embryological derivative to the anatomical and clinical description of cleft lip    Failure of fusion of  maxillary process and  lateral nasal process  with medial nasal  process [ Tessier 1/2]    Failure of fusion in  midline of the  medial nasal  process [Tessier 0  & 1)    Failure of fusion of  medial nasal, lateral  nasal and = maxillary  process [ Tessier 3]    Failure of fusion of  maxillary process with  lateral nasal process  and medial nasal  process. There _ is  fusion of medial nasal  and __ateral __—inasal  process [ Tessier 4]    Failure of fusion of lateral  nasal and maxillary process  [ Tessier5]    Median cleft lip—a very rare condition. Occurs due to the  partial or complete failure of fusion of the two medial  nasal prominences to form the intermaxillary segment. It  is the characteristic feature of Mohr’s syndrome.    Mesodermal Migration: There are various theories to  describe how a cleft occurs. These theories explain that  cleft rises as a result of failure of fusion of the five pro-  cesses. These processes are formed as a result of mesoder-  mal migration resulting in heaping under the ectodermal  layer. Insufficient or late migration of mesoderm leads to  partial or total cleft as a result of epithelial breakdown.   Mesoderm gives rise to the fibromuscular layer of the  lip. The importance of mesodermal migration carries in  itself an important principle of cleft repair, i.e. muscle  approximation. The author’s technique presented later in  this chapter describes this step as an important step in  functional cleft repair. Also the mesoderm has chondro-  genic potential which explains the accompanying deficit  in the development of nasal capsule [4].    Fig. 72.4 (a, b) As the philtrum and premaxilla are derived from the  frontonasal process, their blood supply is from the posterior septal  artery and terminal branches of the ethmoidal artery (a). As the prola-    minal branches of the ethmoidal artery (Fig. 72.4).  Knowledge of this embryological vascular supply is  important while designing the incision on the prolabium  in a bilateral cleft lip repair. As the prolabium derives its  blood supply solely from the frontonasal process, no back  cuts are given during dissection of prolabial flap  (Fig. 72.4). This is discussed again in surgical technique.    artery fails to unite with its counterpart on the other side.  In addition the arcade made by anastomosis of the poste-  rior septal branch with the greater palatine artery through  the incisive foramen is absent. Thus the blood supply of  the premaxilla is derived from three sources: periosteal  supply from the vomer, branches of the sphenopalatine  and ethmoidal artery. This principle is used in anterior  palate repair with concomitant lip repair in bilateral clefts.  It is postulated that anterior palate repair using the vomer-  ine flap can lead to premaxillary necrosis due to cutoff of  blood supply from the posterior septal arteries. However,  in author’s opinion and experience, the premaxilla has a  robust blood supply even after using vomerine flaps for  anterior palate repair [5].    labial artery which supplies the orbicularis oris muscle.  During muscle dissection, the artery is encountered  within the muscle going upward. This vessel should be  identified throughout the length of incision and muscle  dissection and should be carefully cauterised.    bium derives its blood supply solely from the frontonasal process, no  back cuts are given during dissection of prolabial flap (b)    Cleft lip can be diagnosed in the intrauterine stage with the  help of routine ultrasound scanning at different intervals of  gestation. The prenatal diagnosis is usually established dur-  ing the second and third trimester [6]. Recent data suggests  that during the 11-13 gestational weeks, a midsagittal view  of the fetal head, face and brain, in addition to certain mea-  surable abnormalities, such as a smaller palatino-maxillary  diameter, can make grounds for an underlying CLP. 3D  sonography can construct a computerized volumetric render-  ing of the foetus, similar to 3D CT volumetric reconstruc-  tions. Detection rates of up to 75% have been described by  specialist maternal-fetal medicine [MFM] physicians and  radiologists. Thus, prenatal counselling continues to be  important with evolving diagnostic procedures. Although  there is currently no intrauterine treatment of cleft lip and  palate, research has indicated that both mother and child  benefit from early diagnosis and counselling. Prenatal coun-  selling has positive psychological implications on the par-  ents of a child with cleft as they are better prepared and  motivated for treatment.    Anatomy of the cleft lip patient includes two major compo-  nents: the lip and the nose. Both the structures vary greatly in  a unilateral and bilateral cleft lip deformity and are discussed  individually here.   The upper lip is attached above to the nose and blends  laterally into the cheek, curving into the lower lip at the com-  missures. It is formed of muscles and glands covered super-  ficially with skin and lined internally with mucous membrane.  These layers are tightly adherent to the muscles and are  sealed along the free margin (Box 72.1).   2. Muscles: orbicularis oris insertion is displaced in  unilateral and bilateral cleft patients.   3. Vascular supply: superior labial artery, inferior  labial artery and septal arteries are the major blood  supplies of the lips and the nose.    The following anatomical surface components of the upper  lip are to be kept in mind when assessing a patient with cleft  lip (Fig. 72.5). Anatomical equal repositioning of these fea-  tures is essential for an aesthetic and functional outcome  (Box 72.2).   Philtral columns: They are paired bilateral vertical lip  bulges created by the dermal insertion of orbicularis  oris fibres into the skin of the upper lip.   White roll: The white roll is a prominent ridge just  above cutaneous-vermillion border. It appears very  distinct and white/light in colour due to reflection of  light off the skin. This is due to insertion of pars magi-  nalis of orbicularis muscle and absence of hair in this  region.   Vermillion: It’s the red mucosal portion of lip  divided into dry (keratinized) and wet (nonkeratinized)  mucosa.   Cupid’s bow: A curvature of central white roll,  formed by the two lateral peaks as the philtral columns  extend inferiorly.    In the normal lip, the columella is a central straight col-  umn reaching up to the nasal tip. At its base the columella  blends into the nostril sill in front of the nasal floors later-  ally towards the alar bases. The arches of the alae are sym-  metrical with equal bulges of the alar cartilages. The  eversion of the upper lip places it slightly out in front of the  lower lip at the mucocutaneous junction of the upper lip.  There is a continuous 1—2 mm rounded roll from commis-  sure to commissure which tops the vermilion and picks up  white light it coincides in its curves with the peaks of the  Cupid’s bow of the vermilion which has central tubercle  flanked by, each arch of the bow. The abundance of eleidin  in the epithelial cell layers increases the translucency, and  the numerous rich capillaries of the papillae create the red  colour of this area [5].    The orbicularis oris consists of numerous layers of muscle  fibres surrounding the rima oris traversing in different direc-  tions. It is partly derived from muscle fibres of the other  facial muscles which are inserted into the lips and partly  fibres of its own inserted into the skin near the midline. The  main fibres of the lips are oblique and pass from the skin to  the mucous membrane, throughout the lip thickness. In the  upper lip, these fibres group into two bands bilaterally, lat-  eral and medial [total of four bands]: the lateral band origi-  nating from the alveolus of the lateral incisor tooth and the  medial band connecting the upper lip to the septum of the  nose. The area between the two medial bands forms the phil-  trum, below the septum of the nose. The additional fibres for  the lower lip arise on either side of the midline lateral to the  mentalis and merge with the other muscles at the commis-  sure [7].   Orbicularis oris derives from eight muscle components  with their origins in the modiolus at each angle of the mouth.  Orbicularis fibres of one side end by decussating in the  median line with fibres from the opposite side. The orbicu-  laris is composed of four pars peripheralis extending from  the rima oris on the right and left side. Intimately associated  with the pars peripheralis is the pars marginalis with its two  right and left components lying in a plane superficial to the  pars peripheralis and confined to the area beneath the vermil-    lion. Pars marginalis is responsible for fine movement  (speech) and pars peripheralis for gross movement of the lips  (Fig. 72.6a—c). In the presence of cleft, the orbicularis oris  muscle fibres do not decussate transversely across the mid-  line but tend to go parallel to the cleft edges towards the base  of the nose with their integrity divided. In addition, the trans-  verse nasalis muscle, levator labii superioris and depressor  septi do not insert and are prolapsed laterally. They often  contract abnormally which has a ripple effect of the lip and  the nose. Muscles make the most of their advantage exerting  unnatural lateral lifting and distortion of the lip elements in  both incomplete and complete clefts. They play a role in dis-  placement of alar base to the side of cleft and the nasal sep-  tum on non-cleft healthy side.    The major vascular supply to the lip and nose area is derived  from the facial artery, branch of the external carotid artery.  Other additional sources are from the ophthalmic and the  infraorbital arteries. The facial artery gives off inferior and  superior labial branches which arise near the corner of the  mouth and course as the coronary vessels beneath the free  border of the lips deep to the muscle and close to the mucous  membrane. The right and left labial arteries freely anasto-  mose to form a circle surrounding the oral aperture. The  facial artery then proceeds upwards along the nasolabial fold  and gives off the lateral nasal branch and then becomes the  angular artery proceeding up to anastomose with the dorsal  nasal branch of the ophthalmic artery. The posterior septal  artery arising from the sphenopalatine artery in the roof of  the nasal cavity courses down the vomerine groove to the  incisive foramen anastomosing with the major palatine and  ascending septal branches of the superior labial arteries  (Fig. 72.7a, b).   Near the inferior lateral attachment of the ala, the lateral  nasal artery divides to run one branch along the lower border  and another along the superior margin of the lower lateral  cartilage. These branches anastomose in the midline with the  terminal branches of the anterior ethmoidal artery. It enters  the nose and passes along the undersurface of the nasal bone  continuing distally over the upper lateral cartilages to the tip  of the nose. It joins the lateral nasal branches to continue into  the columella anastomosing with the ascending septal  branches of the superior labial artery [5].   Vascular anatomy in a cleft lip has been described picto-  graphically in Fig. 72.8. There is an interruption in the usual  arcade in the upper lip in unilateral clefts. However, there is  sufficient blood supply to both lip elements and the nose to  ensure adequate healing.    Fig. 72.6 (a-c) Concentric band of orbicularis oris forming oral attach to the dermis of the overlying skin at the philtrum. Deeper fibres  sphincter. Upper and lower fibres arise from each modiolus and decus- _ attach to the anterior nasal spine [left]. Note the abnormal attachments  sate in the midline. Superficial fibres upper lip criss-cross at midline to in unilateral and bilateral clefts [middle and right]    Fig. 72.7 (a, b) Vascular  anatomy of a complete lip (a)  and a unilateral cleft lip (b)    The sensory nerve supply to the involved areas of the lips  and nose comes from branches of the fifth cranial nerve, tri-  geminal nerve surfacing through the infraorbital foramen as  the infraorbital nerve and through the mental foramen as the  mental nerve The motor nerve supply to the muscles of the  lips and nose comes from the seventh or facial nerve through  its zygomatic, buccal and mandibular branches.    A thorough knowledge of the normal lip anatomy can help us  understand the abnormal anatomy in cleft. Displacement of  muscle insertions and deformation and functional hypotro-  phy leading to paucity of tissues result in a distorted anatomy  of labial clefts (Fig. 72.9). The following are the characteris-  tics of the cleft lip and nose deformity (Table 72.2):    Fig. 72.8 Embryological basis of vascular anatomy in unilateral and bilateral cleft lip    Normal Bilateral cleft  anatomy —_ Unilateral cleft anatomy anatomy  Labial skin Non-fusion of the lip, the skin One prolabium and  on both sides of the lip is less ___ bilateral lip elements.  projected or drawn out The prolabium is the  central lip element  that has severe  paucity of tissues   White roll __ Lateral side, the white roll The white roll on the    less clear  Mucosa Absence of a labial glandular = Absence of a labial  bed, paucity of compressor glandular bed, paucity  muscles, thinner and finer of compressor  mucosa muscles, thinner and  ©Association of Oral and Maxillofacial Surgeons of India finer mucosa  Orbicularis No muscle decussating inthe Muscle runs  Fig. 72.9 Presentation of a unilateral cleft lip. Note the abnormal anat- 1S midline. Abnormal attachment _ bilaterally up into the  omy of the lip and nose compared to the non-cleft side at alar base alar bases, no muscle    1. Labial skin: Apart from the non-fusion of the lip, the skin    on both sides of the lip is less projected or drawn out. This  leads to a hypoplastic or decreased cutaneous length of  the skin. However, the skin is thicker than in normal indi-  viduals. The lip consists of the skin, orbicularis oris mus-  cle, minor salivary glands and the labial mucosa. These  anatomical planes are important to identify while dissect-  ing the muscle layer. Only 1-2 mm of subdermal  dissection should be done, whereas on the mucosal side,  the plane of dissection is between the muscle on one side  and minor salivary glands and mucosa as a single layer.  . Unequal philtral columns: The philtral columns are on the  non-cleft side, with an obliquity due to discrepancy in  their length leaning towards the contralateral sides.  Matching of the philtral columns of both sides is cen-  tral to a successful lip repair. The philtral columns are the  paired elevated soft tissue structures of the face which  make an important aesthetic subunit. Various surgical  manoeuvres have been used to achieve symmetry of the  philtral columns. The surgical design of rotation-  advancement technique is also based on making the phil-  tral columns of the same height.  . White roll abnormality: From the lateral side, the white  roll gradually diminishes to about 2-3 mm before it dis-  appears. On the medial side, the demarcation of the white  roll is less clear. Identifying the white roll is pivotal in  making incision markings during surgery. A practical tip  is to identify maximum width of the dark/dry mucosa; it  is generally the most pertinent area to mark the point  where the white roll starts diminishing. This is discussed  again in the surgical technique.  . Mucosa: In cleft lip, due to absence of a labial glandular  bed and the paucity of compressor muscles, the mucosa  of the cleft side is thinner and finer. Also, the mucosa  merges with the skin closer to the nose and rolls inward.  This mucosa of the cleft region is considered redundant  and excised frequently. However, in author’s clinical  judgement, this tissue can be converted into a flap to close  the nasal floor, thus precluding the need for any vestibular  releasing incision.  . Nostril skin on the lip: The skin of the lateral alar part, the  columella and part of nasal vestibule intrudes onto the lip  in the upper part. Distinction can be made between nostril  skin and labial skin as the former is finely stippled while  the latter is finely striated and has hair.    rotated outwards, whereas the lateral maxillary segment  is retropositioned. Consequently, there is nasal asymme-  try at the base.    2. Septum: Lower border of the septum is dislocated out  from the vomerine grove, thus twisting the nasal tip and  columella.   3. Columella: Unilateral shortness in vertical dimension is  seen with deflection towards the non-cleft side.   4. Nasal floor: Has a defect in the skin, muscle and bone.   5. Lower lateral cartilage: The cleft alar cartilage is flattened  and more horizontal in its long axis and stretched at an  obtuse angle.   6. Alar crease: Due to the absence of alar cartilage bulge,  alar crease continues across the tip to produce a disjointed  effect.   8. Alar rim: There is a skin curtain of ala that is without  cartilage further reducing the apparent length of the colu-  mella on the cleft side (Fig. 72.9).    The following are the salient anatomical features of a bilat-  eral cleft:    ¢ Prolabium and premaxilla: The prolabium and premaxilla  isolated from lateral segments (lip and maxilla). The pre-  maxilla is not found in the alveolar arch and either pro-  truded or deviated or rotated. This is probably because of  the excessive forward growth of the premaxillary-  vomerine suture and uninhibited forward growth of the  cartilaginous nasal septum (Fig. 72.10).   ¢ The prolabium is the central lip element that has paucity  of tissues. The prolabium has no muscle, is non-mobile  and has a limited blood supply. The white roll on the pro-  labium is rounded and indistinct.   ¢ Nasal deformity depends on the premaxilla and size and  position of the prolabium. The columella is very short or  absent. The base of the ala is positioned laterally and pos-  teroinferiorly. There is a wide nasal base. The deformity  in LLC is presented by the elongated lateral crus and  shorter medial crus. The nasal tip is flat with increased  distance between alar domes. Only in cases of asymmet-  ric bilateral clefts, the septum is deviated.   ¢ The orbicularis oris muscle runs bilaterally up into the  alar bases. There is no muscle on the median lip element  (Fig. 72.4).   ¢ In complete bilateral cleft lips, the labial artery fails to  unite with its counterpart on the other side. In addition the  arcade made by anastomosis of the posterior septal branch  with the greater palatine artery through the incisive fora-  men is absent. The philtrum and premaxilla therefore  derive their blood supply from the posterior septal artery  and terminal branches of the ethmoidal artery.    . ny A  @©Association of Oral and Maxillofacial Surgeons of India    As we discussed in embryology, insufficient or late migration  of mesoderm leads to epithelial breakdown resulting in a cleft.  Thus, a cleft lip presents in various forms, and the management  differs slightly for all forms of cleft. The basic classification is  based on the side of presentation, i.e. left and right and com-  plete and incomplete (Figs. 72.11 and 72.12). The incomplete  cleft lip can be further classified into various types (Box 72.3).   Incomplete clefts can be further divided on the basis of  extent of involvement of the mucosa, skin and nasal  floor.    1. Incomplete cleft lip with mucosal notch not extend-  ing into the skin.   3. Incomplete cleft lip involving the mucosa and skin  extending upwards but not up to the nasal floor.   4. Incomplete cleft lip with Simonart’s band.  Simonart’s band is a bridge of tissue between the  premaxilla and the lateral lip element. Its preva-  lence is approximately 20%.    Similarly, bilateral cleft lip can be divided into complete  and incomplete clefts. Complete clefts can be further divided  on the basis of status of the premaxilla. The premaxilla can  be severely, moderately or mildly protruded. However, this is  a clinical classification and helps in deciding treatment of a  bilateral cleft lip.    Throughout history, many surgeons have attempted to clas-  sify cleft lip and palate in their own ways. Classifications  made have been on three bases: laterality, severity and mor-  phology of the cleft. At the least any classification system  should be able to specify the laterality, extent and severity of    Fig. 72.12 Incomplete cleft  lip with mucosal notch not  extending into the skin. (a)  Incomplete cleft lip with  mucosal and skin notching.  (b) Incomplete cleft lip  involving the mucosa and skin  extending upwards but not up  to the nasal floor. (c)  Incomplete cleft lip with  Simonart’s band    the labial cleft and the palatal cleft necessary for treatment  planning or outcome assessment (Tables 72.3 and 72.4).   Apart from the above-mentioned classifications, there are  various reports of individual classifications by many interna-  tional and Indian surgeons based on their experience and per-  spective. An ideal classification should be simple, clear and  universally acceptable for purpose of communication and  documentation.    Cleft lip repair constitutes the first surgical step in cleft lip  and palate. Each cleft protocol team advocates different tim-  ings for lip reconstruction, with slight variations from the  neonatal period to 6 months and later. Timing of intervention  can be broadly categorised based on chronological age of the  cleft patient or based on certain dental age milestones and  status of dentition (Tables 72.5 and 72.6). There are a num-  ber of protocols adopted by various centres around the world.  Proponents of traditional repair at the chronological age of  10-12 weeks argue that it poses a decreased risk of  anaesthesia-related complications and provides improved  aesthetic outcomes and positive psychological assurance to  the parents. Surgery was traditionally delayed for several  weeks based on the “rule of tens”, i.e. infant weighing a min-    imum of 10 pounds, having a haemoglobin level of 10 g/mL  and reaching an age of 10 weeks. This rule was based on the  fact that the musculature of the lip is more evolved by this  age and thus allows for proper reconstruction [23]. Another  important milestone is the neck holding capacity of the baby.  It is generally present at 3-4 months of age. It is prudent to  wait till this milestone is achieved. This is crucial in cautious  transfer of the infant as he/she is transferred to the operating  room, recovery or intensive care unit and is handled by vari-  ous healthcare personnel.    We have devised a basic treatment algorithm for unilateral and  bilateral cleft lip repair that we follow at our centre. Due to  lack of awareness, prenatal and postnatal counselling and the  social taboo, many patients in India do not report at the correct  age for surgery. As a result, the treatment methods have been  modified based on the age of presentation of the cleft patient  to provide the optimal outcome (Figs. 72.13 and 72.14).    72.5.3 Presurgical Nasoalveolar Moulding  Wider, extensive clefts and bilateral clefts are associated with    significant deformities of nasolabial complex, presenting a  greater surgical challenge in approximating anatomic struc-   (ajered Arepuodsas dISO[OAIQUID OY} JO IJ9]O) aJeTed OY) JO SIO °Z  (SISTYDSO[OoAeOTIOYS) ayeyed Arewurtd pue snpoaaye “diy yaID (2)  (SISTYDSOTOSATB) SNTOSATL IJOID (q)  (ststyosopiayo) dt] YoID (®)    Table 72.4 Incomplete cleft lip can be further divided into minor-form, microform and mini-microform [22]    1. Notched vermilion-cutaneous junction 1. Medial vermilion-cutaneous point less than 3 mm above  the normal Cupid’s bow peak   normal Cupid’s bow peak 2. Deficient vermilion on the medial cleft side  2. Deficient vermilion on the medial cleft 3. Lower cutaneous lip shows a variable glabrous strip    Timing Procedure  After 16 weeks of Cleft lip diagnosis by USG images  pregnancy  Prenatal Discussion with surgeon  Consultation with a geneticist  Neonatal Presurgical orthopaedics  Feeding instructions  12 weeks of age Cleft lip surgery    6-12 months of age Cleft palate repair with intravelar  veloplasty  Orthognathic surgery   Presurgical orthopaedics [NAM]  Orthodontic maxillary expansion  Orthodontic maxillary expansion and  protraction   Secondary alveolar bone graft using  iliac crest particulate cancellous bone  marrow    Orthodontic treatment for dental arch  alignment  Dental arch alignment and levelling    After full eruption of  permanent dentition  Orthognathic surgery for  maxillary advancement  Postsurgical orthodontics    tures, thus obtaining an optimum functional and aesthetic  result. The basic goal of any surgical technique is to restore  normal anatomy and function. Thus in such cases, where it is  difficult to achieve goals of primary repair due to wide discrep-  ancies, presurgical maxillofacial orthopaedic appliances mould  the nasolabial structures through specifically directed forces,  thus reducing the deformity before surgery for an easy repair.  Currently, presurgical nasal alveolar moulding (PNAM)  is a widely used orthopaedic technique for presurgical cleft  deformity correction [23, 24]. PNAM theory is based on the  theory that increased hyaluronic acid content is present in the  infant cartilage, which makes the cartilaginous structure   depression that is evident on puckering 5. Nearly normal length of the hemicolumella, the sill shows  a small depression, slight slump of the alar genu and | to  2 mm lateral displacement and outward flare of the alar    more pliable and plastic. By the age of 3 months, the carti-  lage becomes more rigid with less plasticity. PNAM can sig-  nificantly improve the nasal symmetry, by elongating the  columella, bolstering the alae, narrowing the cleft and restor-  ing the alveolar arch form, thus demonstrating favourable  immediate and long-term outcomes.   PNAM is based on the principles of negative sculpting  and passive moulding of the alveolus, lip and nasal tissues.  An initial impression is obtained, and custom-made plates  are fabricated. A series of modifications are made to the sur-  face of the appliances with the addition and deletion of mate-  rials in certain areas. This process is called negative sculpting  [25]. The purpose of this is achieving approximation and  symmetry of the two maxillary alveolar segments and  addressing the nasal deformity by moulding the cartilage in  anatomical position [26, 27] (Fig. 72.15). The process should  be explained to the parents; insertion of the appliance should  be carefully taught and made to practice. Parents should be  explained the importance of this exercise through videos and  photos of previous patients.    Impression Making A heavy-bodied polyvinyl siloxane  impression material should be used for the first impression.  The infant is held in prone position to keep the tongue forward  and to allow any material or saliva to drain out of the oral cav-  ity and prevent aspiration. This should be done in a hospital  setting to manage any airway emergency in the presence of an  anaesthetist available if needed. Once impression is made, the  mouth should be examined for any residual material.    Device Fabrication The moulding plate is made with clear  methyl methacrylate lined with a soft denture material on the  dental stone model. The borders should be trimmed and  smoothened to prevent any ulceration. The oral surface  should be smooth and polished with good retention and no  extensions into the cleft area.    Insertion and Moulding The moulding plate is to be worn  full-time by the patient. It should be removed for cleaning and  routine hygiene practices to prevent infection and check for  any ulceration. Suckling should be checked with the plate in  position and to check gagging. The plate is secured to the    cheek bilaterally using orthodontic elastics going to the oppo-  site side and secured with surgical tapes. The elastic loop  extends from the retention arm approximately in a 40-45  degree angle, thus pulling the anterior flange of the plate pos-  terosuperior vector for activation. 2 ounces of traction force is  given by stretching the elastic to twice its original. The surgi-  cal tape is applied to a layer of wound dressing material like  micropore tape and not the skin directly. The tape is to be  changed once a day. The tape should be applied to the non-  cleft side first and then pulled over to the cleft side. Weekly  follow-ups should be made to evaluate the moulding plate for  retention and changes in the alveolar segments.    Moulding Plate Modification Selective grinding of acrylic  material is done from the region into which the alveolar seg-  ments are to move. At the same time, soft denture lining    material is selectively added to the plate to direct the alveolar  segments to the midline, as desired. In a patient with bilateral  cleft, the premaxilla is retracted and derotated, to bring to a  normal maxillary arch alignment. An ideal surgical result  may be obtained when 1-2 mm gap remains between alveo-  lar segments.    Nasal Stent When the maxillary alveolar segment approx-  imation has been achieved, the nasal moulding should  begin. The nasal stent is added to the existing moulding  plate in the form of a stainless steel wire projecting out of  the plate outwards going into the nose like a “swan neck”.  A small wire loop can be made on which a bilobed intrana-  sal acrylic component is made with a layer of soft denture  liner. Nasal stent is placed 3-4 mm inside the ala and gently  lifted towards dome until slight blanching is noted.    Fig. 72.15 PNAM treatment  in a case of bilateral lip. (a  and b) Pre- and postoperative  PNAM. Note the changes in  the nasal tip, alar cartilages  and position of the  premaxilla. (c and d) PNAM  device with the nasal stent  and lip taping    Blanching of the nasal tip as the baby suckles activates the  appliance. Lip taping is continued after the nasal stent  appliance is added.   In a follow-up study over 6-9 years, Bennum et al.  observed that patients treated with PNAM within 15 days  after birth maintained satisfactory nasal symmetry [28].  Ezzat et al. compared 12 unilateral cleft lip and palate  patients with PNAM treatment and found narrowing of the  alveolar cleft, increased posterior width of the dental arch,  uprighting of the columella and improved nasal symmetry  [29]. Yang et al. reported similar results from 45 unilateral  complete cleft lip and palate patients [30]. In a large multi-  centre study sample, Ross argued that orthopaedic correction  of the premaxilla failed to stimulate maxillary growth and  thus was not necessary [31].   The authors conducted a study to evaluate the nasolabial  aesthetics on two-dimensional photographs at 6 months post  cheiloplasty. Cupid’s bow, vermilion symmetry, vermilion  notching, premaxillary show at rest, scar aesthetics, colu-  mella height and bialar width were all significantly better in  the PNAM group [32].    There is no universal protocol for management of cleft lip,  and there is a striking diversity of clinical practice. There is a  paucity of higher-level evidence (i.e. systematic reviews and  randomized controlled trials) on cleft lip and palate. There  have been few RCTs comparing individual treatment steps.  The Eurocleft study showed that among the 201 European  centres, 194 different treatment protocols existed for unilat-  eral clefts [33]. Listed below are some standard protocols  followed worldwide.   ¢ Australian Cleft Craniofacial Society Protocol [40].  ¢ European Studies and results [41, 42].    Discussion of each protocol is beyond the scope of this  chapter. However, we have tried to compare and discuss in  detail few protocols for a comprehensive understanding of  cleft lip and palate repair    The basic protocols of cleft lip repair can also be  classified as follows:   2. Primary cleft lip and anterior palate repair.  3. Primary cleft lip and soft palate repair.    Primary Cleft Lip Repair Only: This protocol of early lip  repair at 3—4 months of age following the rule of tens is fol-  lowed popularly at various centres. The author’s centre also  follows the same protocol. The timing of intervention has  been discussed previously in the chapter.    Primary lip and anterior palate repair: was proposed by  Abyholm in Oslo protocol [37]. In the first operation, cleft    Fig. 72.16 Cleft lip and anterior palate repair: Veau’s vomer flap (Veau.  1931). An incision was made on the medial side of the cleft along the  border line between oral and nasal mucosae or in bilateral clefts, along  the free edge of the vomer. A mucoperiosteal flap is raised from the  vomer and turned across the cleft. The lateral edge of the cleft is incised,  and the palatal mucoperiosteum is elevated, allowing the vomer flap to  be put under the mucoperiosteum and fixed with mattress sutures. In the  alveolar area, and in continuity with the vomer flap plasty, the nasal  mucoperiosteum is mobilised on both sides and joined across the cleft to  complete the nasal floor anterior to the vomer flap. Towards the oral cav-  ity, the raw surfaces of the vomer and of the flap are left uncovered    lip repair using Millard technique with simultaneous ante-  rior hard palate closure using a single layer vomer flap.  The mean age for first surgery was 3.3 months. The soft  palate was closed at a mean age of 17.2 months (Fig. 72.16).    Primary lip and soft palate repair: It is a well-established  early palatal closure which causes maxillary hypoplasia.  Because of this reason, many surgeons used to perform pal-  ate repair in two stages, i.e. soft palate first followed by hard  palate. At the time of introduction of this protocol, the soft  palate was repaired along with the lip at around 4-6 months  of age, and the hard palate was repaired at the age of  10-12 years. This was later reduced to 4—5 years.    Complete Lip and Palate Repair: one-stage simultaneous  repair of the entire cleft is a simple and economic treatment of  complete unilateral cleft lip and palate [43]. The concept of  one-stage repair was first introduced in 1958, when Farina  (1958) described the surgical technique. A decreased risk  associated with general anaesthesia, better healing, lower  incidence of fistulae and reduced hospitalization costs has  been the rationale for performing such repair. This repair per-  formed in children above 10 months of age has been claimed  by surgeons with extremely good results without any compli-  cations. Overall, the cleft teams from Brussels, Belgium;  Konya and Zonguldak, Turkey; and Warsaw, Poland, found  that their protocols employing one-stage closure of UCLP  produced favourable morphological results [36, 37, 44, 45].    The evolution of cleft repair was bound to happen  mainly due to the nature of the aesthetics that had to  consider the anatomical parameters, namely:   (e) Philtral columns and equality of length on both  cleft and non-cleft sides.   (f) Minimizing scarring on the anatomical unit of the  lip, i.e. philtral column, philtral dimple and nasal  base.    Broadly over the period of cleft history, lip repair can be  divided into three basic types depending on the design of flap  used (Fig. 72.17). These are straight line repairs (Box 72.4), geo-  metric flap repairs (Box 72.5) and rotation-advancement flap.   ¢ Tennison [1952] and Randall [1959] [57, 58].  e Skoog [1969] [59].   Ralph Millard (1957) [2] revolutionized the cleft repair  technique with most of its principles applicable and widely  used in current day practice. His innovation was in designing  the incisions without disrupting the aesthetic subunits. The  cut as you go technique was simplified further by under-  standing the anatomy of the lip. He realized that two thirds of  the Cupid’s bow, complete with tubercle, white roll of the  mucocutaneous junction, one column and the dimple of the  philtrum, were all present in the non-cleft side but askew and  thus had to be rotated down to normal position [60].  72.6.1.1 Basic Components of Millard’s Repair  (Video 72.1)    rotation flap begins at the peak of the Cupid’s bow [cleft  side], marked along the cleft edge up to the junction with  the columella, and curves under the base, crossing the  midline, but doesn’t cross the contralateral philtral  column. Millard later added a back cut at the end of the  incision, to allow for adequate rotation of the medial lip  element and less tension on the repair [61, 62].  B—Cleft side (advancement).   The incision on the lateral lip element of cleft forms  the advancement flap. It is made along the cleft edge,  extending up to the nasal floor. This incision should  match the length of the incision on the medial side of the  cleft.   C—A small triangular flap attached to the columella from  the non-cleft side left after the incision.    72.6.1.2 Points Marked: The Following Points  are Marked in a Classic Millard’s  Technique (Fig. 72.18a, b)   2. Bow peak on the non-cleft side (distance usually 4 mm).   3. Bow peak on the cleft side (equal to distance between  point | and 2 from point 1).   5. Final extent of the incision following a rotational curve,  skirting the columella-lip junction and extending past  the midline of columella base almost as far as the phil-  trum column on the normal side but no farther.   8. Equidistant point from 6 to 2 marked on the mucocuta-  neous junction (usually 20 mm), and distance between  10 and 8 is equal to 4 and 2.   The vertical distance from the alar base on the normal  side 4 to the height of the non-cleft peak of the bow 2  gives the distance that must be matched ultimately on  the cleft side from its alar base 10 to its peak 8 (usually  around 10 mm).    Despite being seemingly complicated, a simple exercise  of carrying out the points over an illustration of complete  cleft lip shall allow the reader to completely understand the  simplicity of the description (Fig. 72.19). Complete surgical  technique of Millard’s cleft lip repair with the author’s modi-  fication is discussed later in this chapter.   Once the markings are made, the rotation and advance-  ment flaps are designed. The basic aim is to achieve symme-  try of the philtral columns. This can be achieved by the  following methods in a Millard’s repair:    ing length on the cleft side philtral column. plish either of the following goals: closure of nasal sill,  2. Back cut: The role of the back cut comes into force when columellar lengthening or back into the defect created by  the rotation is not adequate to provide enough length to rotation of the flap [63].    match the normal philtral column. It can be made to cross  the midline or made parallel to the normal side philtral  column as in Mohler’s modification.   In the original Millard’s technique, the advancement flap  often disrupts the upper third of the cleft side philtral column.  Also, in wider clefts the advancement flap results in an  unaesthetic scar around the alar base. This led to a series of  modifications to the conventional Millard’s rotational  advancement technique:    1. Mohler (1987) [64]: The medial lip rotation incision  was modified to extend onto the columella. The back  cut was added which was confined to the columella.  The C flap is used to fill the defect created by rotating    the medial lip element at the base of the columella.  Thus it is used for lengthening the shortened columella  (Fig. 72.20).    triangle repair and rotation-advancement from Millard.  It uses a small triangle above the white roll at the out-  set and avoids the use of rotation incision allowing  most scar to be placed along the ideal philtral column  (Fig. 72.21a, b).    In Noordhoff’s words the essential features of this  technique are as follows:  (a) No dissection over the maxillary base.  (b) No “back cuts” in rotation flap.    (c) In cases where the rotation is inadequate, the use of a  small triangular flap of the skin above the “white roll”  will be used to achieve adequate rotation without dis-  torting the philtral column. These flaps heal well and  are aesthetic.   (d) A lateral vermilion flap used for reconstruction of  deficient vermilion on the cleft side Cupid’s bow.   (f) Complete closure of mucosa of all areas using infe-  rior turbinate mucosal flap that allows for reposition-  ing of the lower lateral cartilage and adds mucosa  wherever there is a deficiency.   (g) Fixation of the lower lateral cartilage to the upper lat-  eral cartilage at its base and to the skin with alar  transfixion sutures.   (h) Delayed upper limb rotation-advancement incisions  limiting scars around the ala and nostril floor.   (j) Postoperative splinting with a nasal silicone con-  former to limit wound contracture.   extends up onto the columella 1.5 to 2.0 mm slightly to  the non-cleft side [67]. This yields a wider C flap thus fill-  ing the entire medial defect, allowing for a straight line    (b) Mulliken [68]: Vertical mattress sutures for end-to-  end muscle repair to evert the orbicularis.   (c) Fischer [65]: On both medial and lateral cleft ele-  ments, dissection of the overlying skin from the orbi-  cularis. Dissection on the medial lip is limited to  1 mm from cut edge whereas of the lateral lip extends  to the alar base to eliminate orbicularis bulge.    72.6.2 Step-by-Step Technique of Unilateral  Cleft Lip Repair: Author's Technique  (Figs. 72.23, 72.24, 72.25, 72.26, 72.27,  1226, $2.29, 72.350, (2.31, 42.32, 7235  and 72.34)    Lip Repair:  The authors have presented their technique of lip repair in   ¢ Markings: The most important principle of cleft lip repair  is to identify the normal and abnormal structures. This  includes the length of the philtral columns and the width  of wet and dry mucosa. All the soft tissues should be kept  in mind while designing the flap. No soft tissue should be  discarded or considered redundant.   Deepest point on cupid’s bow, peak on non-cleft side  and normal philtral column. (To make the philtral column  prominent, one may use a two-pronged nasal hook to pull  and retract the columella.)    Fig. 72.23 (a) Mark the highest point on the Cupid’s bow (cleft side), and also notice the philtral dimple. (b) Mark the future philtral column, and  continue it up to the columella without cutting across the columella    Fig. 72.24 From the peak of Cupid’s bow on the cleft side, mark the  incision on the dry mucosa till the junction of wet and dry mucosa    Fig. 72.25 Marking of C flap: A triangular flap between the mucosa  and the future philtral column    e Mark the highest point on the Cupid’s bow (cleft side),  and also notice the philtral dimple (Fig. 72.23a).   At this point the surgeon should compare the mark with  the philtral column on the normal side. It might appear  shorter; however, it will increase in length once the mus-  cle is dissected from the abnormal attachment. The back  cut discussed previously is used for adequate rotation of    the cleft side philtral column. The back cut should be  made after the muscle closure.    incision on the dry mucosa till the junction of wet and dry  mucosa (Fig. 72.24).    Fig. 72.26 M flap: The mucosal element on the non-cleft segment  after raising the C flap becomes the M flap and is raised to expose the  underlying muscle    and mucosa junction down to the mucosa to keep enough  mucosa for nasal layer closure (Fig. 72.25).   e C flap originally described by Millard was used to aug-  ment the lateral lip at the insertion of alar base. We use the  C flap either to create the nasal sill or if a back cut is given;  it can be used to reconstruct the columella-lip junction.   ¢ M Flap: The mucosal element on the non-cleft segment  after raising the C flap becomes the M flap and is raised to  expose the underlying muscle (Fig. 72.26).   ¢ Rotational Flap: The muscle is now exposed, and the  preparation of the lateral element can be divided into  three easy steps:   e Oral mucosal layer: Separation of this layer from the  muscle bulk can be identified with the plane where the  minor salivary glands exist. Bleeding is generally encoun-  tered in this plane and should be managed early to reduce  blood loss and keep a good plane of dissection.   e Skin-muscle dissection: The incision between this plane  is to ensure just adequate separation to provide room for  suturing the muscle bulk. Overexposing the muscle not  only leads to excessive swelling postoperatively but also  distorts the natural anatomical curves of the non-cleft ele-  ment. On the cleft side, only 1-2 mm of subdermal dis-  section should be done. Closure of the skin later reinforced  by the underlying muscle gives better elevation of the  future philtral column as compared to overzealous separa-  tion of the muscle from the overlying skin.   e Release of abnormal muscle attachment: The abnormal  attachments are usually near the alveolus and the base of  the columella. At this point blunt dissection can be done  to straighten out the septum.    Fig. 72.27 On the side of the cleft, mark the point B. From the B point,  extend the incision along the mucocutaneous junction till point D. From  point D, marking goes into the nose to separate the nasal mucosa and  the skin [D1]   ¢ On the side of the cleft, mark the point B. First identify  the white roll, and look for the point where the white roll  starts to diminish; that is the exact point to join the Cupid’s  bow. Drop an imaginary line from this point to the junc-  tion of dry and wet mucosa. The maximum mucosal width  is present at this point.    Fig. 72.29 Incision starts from the deepest point of the Cupid’s bow  till the columella base. The plane of dissection is just above the  muscle    e From the B point, extend the incision along the mucocu-  taneous junction till point D. Point D is a point at the edge  of the lip at the junction of the skin and mucosa. From  point D, marking goes into the nose to separate the nasal  mucosa and the skin (Fig. 72.27).   e After marking the L flap, the incision is continued down  to the alveolus, to free the abnormal muscle attachment at  the base of the alveolus. In a classic Millard’s technique,  additional incision is given into the vestibule on the cleft  side to get adequate mobilization of the advancement flap  and medicalization of the cleft side alar base for nasal sill  closure. Few surgeons also advocate subperiosteal or  supraperiosteal dissection, through the intraoral incision  at the pyriform region. However, in the author’s experi-  ence, the need for this vestibular incision is not always  necessary. An “L” flap can be designed from the mucosa  of the cleft side as shown in the figure. This flap is contin-  ued upwards into the nasal mucosa and not towards the  alveolar mucosa. The importance of this lies in the fact  that, once harvested, the flap is retracted upwards into the  nasal base and is thus used for closure of nasal sill.  Moreover, due to this upward pull, the abnormal alar base  attachment that leads to flattening of the alar rim is cor-  rected. Thus, it helps in reducing the nasal symmetry  (Fig. 72.28).   e Incision starts from the deepest point of the Cupid’s bow  till the columella base. The plane of dissection is just  above the muscle. On the mucosa the incision continues  till the junction of the dry and wet mucosa to expose the  muscle. Insert a skin hook which will stretch the lip and  aid in further dissection. Note: The superior labial artery  can be encountered at this point and may need cauteriza-  tion (Fig. 72.29).    Fig. 72.30 Nasal layers are now sutured from both the cleft and non-  cleft sides and sutured using a 4.0 Vicryl    e Begin the incision from the point where the white roll  diminishes, and carry it along the marking between the  skin and mucosa to reach the junction between the nasal  skin and mucosa.   ¢ A small mucosal triangle containing the dark mucosa is  maintained, and incision is then carried out to raise the L  flap.   ¢ Once the L flap is raised, the muscle of the cleft side ele-  ment is exposed.   ¢ Incision is made between the mucosa and muscle similar  to the non-cleft side in the plane of existing minor salivary  glands.   e The incision between the skin and muscle is similar to the  lateral element.   ¢ The abnormal muscle attachments on this side are at the  base of the alar and the pyriform region that would require  subperiosteal dissection to release the attachment.   e The final step of closing the flaps into desired position  begins with insetting the L and M flaps.   e Using the M flap is optional. The author generally dis-  cards the M flap but occasional uses it to reduce tension  while doing the nasal floor repair in very wide clefts.   ¢ The L flap is used to create the nasal layer on the cleft side  by lining it between the nasal skin and the nasal floor.   ¢ Creating the Nasal Floor: Nasal layers are now sutured  from both the cleft and non-cleft sides and sutured using  a 4.0 Vicryl (Fig. 72.30).   e At this point of time, the septum is exposed. When the  nasal layer is being raised, if required the septum can be  straightened.    Suturing the Oral Mucosa: Begin at the point where the  wet and dry mucosae meet. The alignment of these two  points from both elements is crucial for good mucosal  repair. The rest is completed till the alveolar base. The  suture material used here is 4.0 Vicryl. The dry mucosa  will be closed last (Fig. 72.31).   Muscle Suturing: The preference is to suture the muscle at  the junction of white roll and Cupid’s bow. The suture  allows reassessment of adequate rotation of the flap to  create equal length of the philtral columns. A back cut can  now be placed to accommodate for discrepancies. The  back cut is made parallel to the existing philtral column at  the base of the columella.   Muscle layer suturing is then completed carefully  reorienting the fibres at equal height and bites from  both elements. At this stage the lip anatomy should    Fig. 72.33 (a) Skin suturing. (b) Note the matching of the white roll    correspond to final anatomy, and the skin should be  passively seated over the muscle layer. The suturing is  completed using 4.0 Vicryl, and the knots are cut flush  to prevent any extrusion of sutures on the skin surface  (Fig. 72.32).   Skin Suturing: The first step in suturing the skin is to eval-  uate the area where the C flap is going to be utilized and  also the dimension of the flap needed. The excess flap can  be trimmed or in some instances completely discarded  (Fig. 72.33a).   The preference of the C flap is to use it as a hemi-columella  or nasal sil. Using the C flap into the back cut defect cre-  ates an unnatural scar across the cutaneous lip and colu-  mella junction.   Once the C flap is tucked beneath the skin, excess skin  tissue if any is trimmed, and suturing begins from the  base of the columella down to the vermilion. The suture    used here is 5.0 Vicryl Rapide or 6.0 Vicryl Rapide  (Fig. 72.33b).   ¢ Dry Mucosa Suturing: At the end of skin suturing, the  vermilion continuity is established by using the  V-shaped mucosal flap established from the cleft seg-  ment tucked into the non-cleft mucosa. At this stage  care should be taken to secure a suture beneath the ver-  milion for muscle repair, and the mucosal stitch should  be passive to reduce necrosis of the mucosal tip  (Fig. 72.34).   e A good repair depends upon minimal handling of the  tissues and a tension-free closure of all layers espe-  cially the skin as the muscle bears the stress of tension  forces.    James Barrett Brown said “Bilateral clefts are twice as hard  as unilateral clefts, and the results are less than half as good”  [69]. Bilateral cleft lip repair can be one-stage or two-stage.  Proponents of one-stage repair stress on creating a symmet-  ric, balanced lip. This is indicated in cases of complete or  incomplete symmetric bilateral clefts or where the premax-  illa is within the arch. Two-stage repair is indicated in the  presence of a small prolabium, an asymmetric cleft or a pro-  truded premaxilla. Proponents of two-stage repair advocate  this technique for conversion of a bilateral into unilateral  cleft, to encourage the growth of prolabium and to avoid  excessive lip tension. In earlier techniques of bilateral lip  repair, excision of the prolabium was made mistakenly  assuming it to be a displaced columella. This was because  surgeons failed to recognize the potential of the prolabium to  grow in width and height when attached to the dynamic lat-  eral lip elements.    Principles of Bilateral Cleft Lip Repair: Certain key points  and landmarks need to be kept in mind while considering a  bilateral cleft lip repair. The following principles of bilateral  cleft lip repair should be adhered to:   1. Symmetry must be established. In case of staged repairs,  this is hindered which lead to asymmetrical results.   2. The surgeon should anticipate a fourth dimensional  changes that occur with growth. Failure to account for  this may result in a widened philtrum. This is attributable  to slower-growing areas such as the lengthening colu-  mella and projection of the nasal tip, compared with  faster-growing areas such as the philtral width [70] Thus,  there is a need to undercorrect fast-growing areas and  overcorrect the slow-growing structures.   3. Prolabium: No matter how small it is, the prolabium is  always sufficient for reconstruction. It should always be  used for reconstruction of the midportion and not used for  partial reconstruction of the philtrum and columella.  When white line is present in the prolabium, it must be  used, however, a short prolabium pulls down nasal tip cre-  ating a secondary nasal deformity.   4. Premaxilla: Presurgical orthopaedic treatment should be  done only to expand the maxillary segments. Closure and  joining the muscle at the midline create enough pressure  to retroposition the protruding premaxilla. Sometimes,  resection of the vomer behind the vomerine-premaxillary  suture can be done, and the premaxilla can be reposi-  tioned using plating or K-wire with or without bone graft.   5. Vermillion: There is a very narrow strip of vermillion  present in a bilateral cleft lip. A vermillion flap from lat-  eral lip elements should be taken for fullness and protru-  sion of the lip.   6. Muscle repair: As the prolabium is without muscle fibres,  muscle continuity under the prolabium is necessary for a  functional lip. There is a need to release the abnormal  attachment at the base of the ala from the vertical to hori-  zontal and functional attachment.   7. The nasal deformity can be addressed either primarily or  secondarily.   Bardach used a straight line repair. The prolabium was used  for the entire central portion of the lip. This caused a problem  in case of a short prolabium or a protruded premaxilla [71].  Salyer also used a straight line repair. In his repair, no tissue  is discarded, the entire prolabium is lengthened and philtral  and skin flaps are used for vestibular lining [72].   Millard’s repair allowed rotation of the Cupid’s bow with the  gap filled from skin advanced from the lateral element [73].  It allowed complete elevation of the prolabium and suturing  of the orbicularis across the premaxilla. In addition, Millard  created lateral segments of the prolabium as “forked flaps”.  These flaps were banked to add columellar height at a later  stage, thus addressing the vertical height deficiency, and it  also corrected the wide alar bases (Fig. 72.35a—e). The key  elements of bilateral lip repair are given in Box 72.6.    repair and synchronous anatomic positioning of the alar car-  tilages with sculpturing/draping of the nasal soft tissues. It  consists of following elements:   e Suspension over the ipsilateral upper lateral cartilage with  intercartilaginous suture.    Markings: Fig. 72.36 shows the marking of the prolabial flap  and the lateral flaps.    ¢ Once all incisions are designed, the lip is infiltrated with  1:100.000 epinephrine. We can start with either the prola-  bium or lateral flaps. Grab the lip between fingers for bet-  ter control during incision and bloodless field.    Incision starts on the prolabium following the previous  markings, the medial flap is for philtral reconstruction,  and two laterals segments of the skin are discarded  (Fig. 72.37a).   The philtral flap is dissected, leaving a generous amount  of deeper soft tissues attached. The flap is raised in a pre-  periosteal plane off the premaxilla and up to the base of  the columella (Fig. 72.37b).   Next step is creation of mucosal flap from the prolabium  for sulcus reconstruction and exposure of anterior nasal  spine.    Incision in lateral lip following the marks in the skin and  mucosa of the vermillion is made (Fig. 72.38).   Incision is carried on the vermilion-cutaneous junction,  dissecting the vermilion to the point where the peak of the  Cupid’s bow is marked.   Full thickness cuts are made through the orbicularis oris  and the oral mucosa of the upper lip.   Incision in the sulcus to aid in the detachment of the  abnormal lateral lip element, especially the muscle.  Those incisions facilitate mobilization of the lateral lip  elements so they can be brought up and over the premax-  illa which aids in decreasing tension.    Fig. 72.37 (a) Marking of the prolabium flap and lateral flap. (b) The prolabium flap dissected    The muscle is dissected as a separate layer from the  mucosa not from the skin. Undermining of the soft tissue,  dissection and release are carried up to the inferior orbital  nerve.   Subperiosteal dissection of the pyriform aperture towards  the frontomaxillary pillar, to release the ala from its  abnormal insertions.   e Mucoperiosteal flap from lateral nasal wall and muco-  perichondrial flap from the nasal septum are sutured  to form the nasal floor. This helps to bring the base of  the ala medially, thus narrowing the width of the  nostril.   e Advance prolabial mucosal flap superiorly to establish  the lining of the labial sulcus, trimmed as needed, and  fixing it to the periosteum inferiorly to the nasal spine.   e Medial advancing of mucosal flaps and fixation to  the mucosal flap of the prolabium, previously fixed.  Then they are sutured together in the middle line  from inferior to superior, starting in the red line (key  stitch).   e Apposition of the muscle is done from distal (key  stitch) to proximal area (Fig. 72.39).   e Proximal segment fixed to the periosteum of the ante-  rior nasal spine in the middle line.   e The midportion of the vermilion is reconstructed by  bringing lateral vermilion flaps below the philtrum  flap (Fig. 72.40).    Fig. 72.40 Position of the prolabium to create the future philtral  column   e Preventing or minimizing lip tension is the key to suc-  cessful bilateral cleft repair (Fig. 72.41).   e Excessive tension: tethering of the columella,  increased scarring and facial growth problems.    A variety of options exists to address the nasal deformity  with cleft lip. These include preoperative nasoalveolar  moulding, overcorrection of the nostril width and alar car-  tilage at the time of lip repair and postoperative use of  nasal conformers. Primary treatment of the nose at the  time of lip repair has become popular, in order to gain  early restoration of the symmetry by repositioning the alar  cartilage and lengthening the columella. However, relapse  is frequent due to the elastic deformed alar cartilage.  Various theories and opinions have been popularized  regarding correction of the septum, to either straighten the  septum or leave for later correction. A study done by  Mancini et al. involves three-dimensional analysis of uni-  lateral cleft lip and palate patients treated with PNAM and  primary rhinoplasty, which demonstrated significant  improvements in nasal projection, columellar length, nasal  symmetry and nasal width [74].    Postoperative wound care is extremely important in deter-  mining the results of lip repair and is often a factor resulting  in the need of a lip revision.    1. Suture area should be cleaned daily with saline and baby  soap twice; topical application of antibiotics is recom-  mended for 10 days.   2. 3 weeks post-op, we recommend to massage the scar  towards the mucosa to prevent scar contracture.   3. Massage can be done with vitamin E cream/silicone gel/  oil. It is recommended to massage for at least 6 months.    Improper surgical technique and tissue dissection can lead to  certain undesirable outcomes. Other factors such as wide  deformities, severely displaced premaxilla, inadequate post-  operative care, poor healing and infection can also lead to  aesthetic results. Understanding the process and severity of  the outcome helps in addressing the problem in secondary lip  repair or lip scar revisions. The outcomes can be divided into  the following types:    ¢ Mucosal notching—As pointed above, the mucosal dis-  section should always be in the plane between the mus-  cles and the mucosa plus minor salivary glands. Failure to  maintain that results in a thin mucosa that inverts after  suturing. This leads to mucosal notching. As a trainee,  one can also give mattress sutures to achieve mucosal  eversion. In case of very mild mucosal notching present-  ing at 3 weeks, it is advised to continue the massage. If  notching persists after 6 months of lip repair, it can be  treated by surgically improving placement of muscle;  thus we recommend a lip revision.   e Scarring—A scar can present in various forms. A scar can  be linear but hypertrophic in appearance. Such scars can  be avoided if proper massaging is done in the postopera-  tive phase. If the scar has keloid tendency, triamcinolone  injections are to be given at an interval of 15 days fol-  lowed by vigorous massage.   ¢ Contracture—A scar can also present as a gross or mild  vertical contracture. This usually results due to inadequate  rotation, thus pulling the lip towards the nose resulting in  vertical shortening of cleft side philtral column. Improper  muscle closure or overzealous separation of the skin from  the muscle can lead to scarring of the skin.   ¢ Complete breakdown of the surgical wound may be the  most severe adverse outcome in the immediate post-oper-  ative phase.    Scarred fibrous tissues with poor vascularity always make  secondary surgery more challenging. Dissection and re-  approximation of surgical landmarks are difficult in such  cases. The basic surgical principles that should be followed  are identification and preservation of all the vital anatomic  structures.    1. Unilateral.  e The scar is not in line with the natural philtral  column.  e The lip length is short.  e There is a mucosal notching.  e There is a white roll to Cupid’s bow mismatch.  e There is a nasolabial fistula.  2. Bilateral.  e There is a wide philtral column.  ¢ Mucosal notching.  e Whistling defect.  ¢ No sulcus depth.    In our course of learning of cleft, we often understand  embryology, anatomy and the surgical technique as separate    . . ,  @©Association of Oral and Maxillofacial Surgeons of India    concepts. In this chapter, we have tried to integrate them and  tried to explain the rationale behind the surgical steps.  Embryological basis of normal anatomy and then of cleft is  pivotal to understand the arrangements of muscles, the vas-  cular supply and thus the basis of incisions. We have  described our surgical technique of cleft lip repair with long-  term follow-ups. In the congenital deformity of cleft where  there is paucity and deformation of tissues, preserving the  tissues during surgery is one of the important principles of  lip repair.    Figures 72.42, 72.43, 72.44, 72.45 and 72.46 represent cases  of operated unilateral and bilateral cleft lip with long-term  follow-ups.   Figures 72.47, 72.48, 72.49 and 72.50 represents cases of  lip revisions with follow-ups.    Fig. 72.42 (a, b) Pre operative (a) and postoperative (b) Photograph of repair of unilateral cleft lip using author’s technique of lip repair [7-year    : I Ai  @©Association of Oral and Maxillofacial Surgeons of India    Fig. 72.43 (a, b) Another case of a 3-month-old female of complete unilateral cleft lip repaired. Left, preoperative; right, postoperative after a  4-years follow-up    Fig. 72.44 (a, b) Operated case of an incomplete cleft lip, 2-year follow-up    Fig. 72.45 (a, b) Pre-op and post-op photograph of a case of bilateral cleft lip repair, 5-year follow-up    Fig. 72.47 (a, b) A case of mucosal notching in an adult lip (a) Postoperative image after a 2-year follow-up (b)    Fig. 72.48 (a, b) A case of operated unilateral cleft lip with mucosal notching and vertical scar contracture (a) Postoperative image after lip revi-  sion (b)    Fig. 72.49 (a, b) An operated case of bilateral cleft lip before (a) and after (b) lip revision    Fig. 72.50 (a, b) A case of an operated bilateral cleft lip with protruding premaxilla and a wide lip (a) Postoperative image (b) after lip revision  and premaxillary repositioning    Kadir A, Mossey PA, Blencowe H, Moorthie S$, Lawn JE,  Mastroiacovo P, et al. Systematic review and meta-analysis of the  birth prevalence of orofacial clefts in low- and middle-income  countries. Cleft Palate Craniofac J. 2017;54:571-81.    . Millard DR Jr. Cleft craft: evolution of its surgery. In: The unilat-   Cleft craft: evolution of its surgery. In:  Embroyological theories, vol. 1. Boston: Little, Brown; 1976.    . Millard DR Jr. Cleft craft: evolution of its surgery. In: Anatomy in    . Ghi T, Perolo A, Banzi C, et al. Two-dimensional ultrasound is accu-    rate in the diagnosis of fetal craniofacial malformation. Ultrasound  Obstet Gynecol. 2002;19:543-51.    . Davis JS, Ritchie HP. Classification of congenital clefts of the lip    . Brophy TW. Cleft palate and harelip procedures. Int J Orthod Oral    Kernahan DA, Stark RB. A new classification for cleft  lip and cleft palate. Plast Reconstr Surg Transplant Bull.  1958;22:435-41.   Harkins CS, Berlin A, Harding RL, Longacre JJ, Snodgrasse  RM. A classification of cleft lip and cleft palate. 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It was Kilner who said, “Ask not for a spatula and torch to  check your cleft palate repair, but listen to your patient  speak.” By this obvious but profound statement, he drew the  cleft surgeons’ attention to the fact that gone are the days of  breakdowns and fistulae and that if your child does not speak  well, your operation is a failure, for such a child would be  out of the mainstream of life forever. In spite of the advances  in technique and execution, experienced cleft surgeons all  over the world still struggle to obtain perfect speech in a  large percentage of cases.   In view of the obvious difficulties of intraoral surgery, it is  not surprising that cleft lips were repaired way before any-  one tried to repair a cleft palate. Credit for the first successful  repair of a cleft palate goes to Le Monnier, a French dentist  from Roven. Le Monnier in 1766 cauterized to freshen the  cleft edges and sutured them successfully [1].   Cleft surgery then passed through a stormy period of  uncertainty in the hands of giants like Ferdinand von Graefe  [2], Roux, Dupuytren [3], Dieffenbach [4], and Warren [5].  Mucosal flaps were used, and even lateral osteotomies were  tried to move the hard palate medially. In 1859, almost a  hundred years after the first hard palate was repaired, von  Langenbeck [6] emphasized the need to raise mucoperiosteal  bipedicled flaps to repair a palate. Langenbeck procedure  was a fundamental breakthrough, and with this major  advance, breakdowns of the palate were reduced. In its wake    Electronic Supplementary Material The online version of this chap-  ter (https://doi.org/10.1007/978-98 1-15-1346-6_73) contains supple-  mentary material, which is available to authorized users.    P. V. Narayanan   Consultant Plastic Surgeon, Jubilee Mission Medical College and  Research Institute, Thrissur, Kerala, India   Department of Plastic Surgery, Burns and the Charles Pinto Centre  for Cleft Lip, Palate and Craniofacial Anomalies, Jubilee Mission  Medical College and Research Institute, Thrissur, Kerala, India    © The Association of Oral and Maxillofacial Surgeons of India 2021    refinements followed. In 1931, Victor Veau [7] parted from  the bipedicled flap to single pedicled flaps based on the  greater palatine vessels. Veau stressed the importance of  repairing the nasal lining of the palate and the need to  lengthen it.   In 1937, Kilner [8] working in Oxford and Wardill [9]  working in Newcastle on Tyne independently used a four  flap procedure for the complete cleft palate.   The weakness of this procedure was a high fistula rate at  the junction of the four flaps. In the 1940s, Dorrance [10],  Cronin [11], and others used various flaps to lengthen the pal-  ate. In 1966 Millard [12] introduced his island flaps based on  the greater palatine arteries to lengthen the nasal lining. Ravin  Thatte [13] went a step further and took two island flaps one  for lining and one for cover and used a tongue flap on the  denuded hard palate. All these procedures had their day but  were short lived in popularity. However, special mention must  be made of the buccal myomucosal flap originally called the  cheek flap by Padgett [14]. This flap was revived 30 years later  by Murari Mukherjee [15] of Calcutta. He changed the direc-  tion of the flap. Recently Ian Jackson has introduced muscle  into this mucosal flap to make it more robust, and he calls it a  myomucosal flap. He uses it in all his palates to lengthen the  nasal lining by 1.5 cm and believes that as a result he achieves  better speech. Robert Mann [16] does a Furlow’s and coves the  residual raw areas with two buccal flaps. His rationale is that  there is deficiency of tissue in the palate and therefore, on first  plastic surgical principles, bring in tissue from outside. This  may become the philosophy of the future.    The primary palate is derived from the intermaxillary seg-  ment derived from the frontonasal and medial nasal    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1 -15-1346-6_73    prominences. The main part of the definitive palate is formed  by two shelf-like outgrowths from the maxillary promi-  nences. These outgrowths, the palatine shelves, appear in the  sixth week of development and are directed obliquely down-  ward on each side of the tongue (Fig. 73.1a and b).   In the seventh week, however, the palatine shelves ascend  to attain a horizontal position above the tongue and fuse,  forming the secondary palate (Fig. 73.2a and b). Anteriorly,  the shelves fuse with the triangular primary palate, and the  incisive foramen is the midline landmark between the pri-    mary and secondary palates. At the same time as the palatine  shelves fuse, the nasal septum grows down and joins with the  cephalic aspect of the newly formed palate (Fig. 73.3a and b).   The secondary palate lies posterior to the incisive fora-  men and consists of the bony hard palate anteriorly and the  soft palate posteriorly, terminating at the uvula. The hard  palate consists of the palatine bony shelves on either side,  attached to the vomer in the midline. The soft palate consists  of a sandwich of muscles enveloped by oral and nasal  mucosa.    The muscles of the soft palate include intrinsic muscle, i.e.,  musculus uvulae, and the insertions of several extrinsic mus-  cles. Apart from this, large amount of.glandular material is  present in the anterior inferior portion of the velum and an  anterior aponeurosis. Extrinsic muscles of the velum include  the tensor veli palatine, levator veli palatini, palatopharyn-  geus, palatoglossus, and fibers of the superior constrictor.  Pharyngeal muscles usually described as having functional  role in velopharyngeal movement include the superior con-  strictor and the salpingopharyngeus (Fig. 73.4).   Following is a tabular summary for the muscles of palate  and their abnormal anatomy in a cleft palate (Table 73.1).   From functional standpoint, it is apparent that the levator  veli palatini muscle is the principal and quite possibly the  only muscle to function for elevation of the velum in speech.  The differences between the normal and the cleft arrange-  ment of the muscles of velopharyngeal closure occur because  the muscles extending toward the central line of the soft pal-  ate cannot attach themselves in the midline of the velum so  they insert at some substitute points. These points prevent the  muscles from becoming fully functional, and therefore their  development is retarded. With the preservation of normal  origins, the atypical insertions and hypoplasia of the muscles  are the main pathological features in the cleft palate. The  abnormal insertions of levators in clefts illustrate that the  function of these muscles in cleft palate is almost opposite to  that in normal one. While the muscles of both sides normally  join in the raphe to form a sling lifting the palate upward, in  cleft palate each muscle pulls its own half of the soft palate  in an entirely different direction, i.e., superolaterally, causing  further widening of the cleft.    The internal maxillary artery gives off the descending pala-  tine artery, which in turn gives off several branches to the  tonsils and soft palate. It then passes through the posterior  palatine foramen, just above the periosteum, and proceeds  forward close to the alveolar margin on each side as the  greater major palatine artery to the incisive fossa. At that  point it sends terminal branch through the incisive foramen  to anastomose with the terminal branch of the sphenopala-  tine artery. The vascular supply of importance is discussed  under two headings, anterior and posterior palate.   The blood supply to the anterior alveolar process of the  maxilla comes from the arterial complex composed of the  major palatine, anterior and superior alveolar, and branches  of the sphenopalatine artery. The posterior septal artery  arises from the sphenopalatine artery in the roof of the  nasal cavity and courses down the groove of the vomer to  the incisive foramen. In the complete bilateral cleft lip and  palate, the union of the superior labial arteries is lacking;  thus they do not contribute to the blood supply of the phil-  trum. Also the anastomosis of the posterior septal artery  with the major palatine artery is absent. Therefore premax-  illa and philtrum must derive their blood supply from the  posterior septal artery and to some degree from the lateral  and terminal branches of the anterior ethmoid vessels  which pass through the columella. There is usually one  well-developed vessel on either side of the premaxilla in  the region where the incisive foramen should have been.  Each of these vessels moves anteriorly and inferiorly into    palate demonstrated in a  complete cleft of the lip,  palate and alveolus (bilateral)   Originates from the scaphoid  fossa at the base of the  medial pterygoid plate, spina  angularis of the sphenoid and  from the cartilaginous part of  the auditory tube    Arises from the petrous part  of the temporal bone and  from the cartilaginous part of  the Eustachian tubes   The muscle descends  anteroinferiorly and winds  around the pterygoid hamulus,  to which some fibers are  attached, and passes into a  tendon that fans out to form  the palatine aponeurosis few  fibers are attached to the  maxillary tuberosity   The muscle descends on either  side, enters the intermediate  40% of the soft palate, and  forms a muscular sling with its  counterpart on the other side   The main role of the  tensor is to dilate the  Eustachian tube and its  role in speech is  insignificant    When the paired muscle  contracts, it elevates the  soft palate superiorly and  posteriorly to enable  closure of the  velopharyngeal sphincter.  The latter is formed by the  soft palate anteriorly, the  posterior pillars of the  fauces on either side, and  the posterior pharyngeal  wall posteriorly   In a cleft palate child, the  palatine aponeurosis is  deficient, especially medially    In a cleft child, as there is  obviously no continuity  across the midline due to the  cleft, there are abnormal  attachments of the levator  muscle to the  palatopharyngeus muscle  posteriorly, to the edge of the  cleft medially, to the tensor  veli palatini, and to the  posterior edge of the hard  palate anteriorly   Has a palatine portion, a  pterygopalatine portion and  the salpingopharyngeal part.  It arises from the lateral and  posterior part of pharynx and  attaches into the velum. Its  superior fibers arise from  complex intermingling with  the superior constrictor  muscle. Lower fibers of the  palatopharyneus arise from  the inferior part of the lateral  wall of the pharynx, medial  to the middle and inferior  constrictor muscles. Some  fibers may arise from the  thyroid cartilage. These lower  fibers pass through the  palatopharyngeal arch to  insert into the velum    Musculus uvulae Arises from the posterior  nasal spine and the palatine    Superior Quadrangular muscle in the  pharyngeal upper third of the posterior  constrictor pharyngeal wall. Origin at   It is found in the posterior  pillar of the fauces. The fibers  pass horizontally into the  posterior three fourths of the    the uvula. The rest of the  uvula contains only mucous  glands    pharyngeal wall, and merge  with the corresponding fibers  of the opposite side forming a    raphe, which runs in the  midline from the pharyngeal  tubercle of the occipital bone  through the entire length of  the pharynx   The muscle helps to  narrow the velopharyngeal  opening by bringing the  palatopharyngeal arches  together    The paired muscle forms  the anterior part of the  sphincter and narrows the  isthmus. It is antagonistic  to the levator in its action,  drawing the palate  inferiorly   Contraction of the muscle  aids the levator in forming  the levator eminence,  which is a hump like  projection formed  proximal to the uvula and  aids in closure of the  velopharynx during  speech   The upper most fibers are  responsible for the  formation of the  passavant’s ridge, which is  a projection on the  posterior pharyngeal wall  during speech. However,  the edge is usually below  the level of closure of the  velopharyngeal sphincter,  and in only about one  third of the patients, it is  believed to contribute to  closure of the sphincter  (the mistake of passavant)   The muscle is relatively well  developed in the cleft palate  child and ends partly along  the cleft edge and partly along  the posterior edge of the hard  palate. Some fibers pass along  the edge of the cleft along  with the levator to form the  muscle of veau    The presence and extent of  the muscle in a cleft palate  child is disputed.   It is also supposed to be  absent in occult submucous  cleft patients    the philtrum and forms an arcuate anastomosis across the  midline in the inferior part of the philtrum.   The greater palatine artery supplies the oral surface of the  hard palate and gives off a few fine branches which perforate  the horizontal plate of the maxilla to supply the nasal mucosa.  It also sends twigs to the gingiva and the palatoglossal arch.  The lesser palatine artery supplies the anterior half of the oral    surface of the soft palate. A branch of the facial artery, the  ascending palatine artery, is the largest vessel entering the  soft palate. It ascends on the lateral side of the superior con-  strictor muscle to turn downward and forward into the soft  palate, between the tensor and levator palati giving small  branches to these muscles. Twigs from the tonsillar and  ascending pharyngeal arteries also reach the soft palate. In the  secondary palate, the existence or absence of cleft makes little  difference to the vascular pattern. The palatal mucoperios-    Major palatine artery  Incisive foramen  @©Association of Oral and Maxillofacial Surgeons of India    teum is detached from its bony base in the palatal pedicle flap,  and as a result the recurrent bony branches are severed. These  branches result in bleeding from their cut stumps at the bony  surface. This may be judged insignificant at the time of sur-  gery; however, after the flap is repositioned, should bleeding  continue, blood may pool beneath the repositioned flap [17].    Many of the historical and contemporary classifications have  been discussed in brief in the Chap. 72 on cleft lip. However,  Veau’s classification for palate is the most practical and  therefore is mentioned again here.    Submucous cleft palate exhibits at least one of Calnan’s  three criteria [17]:    (a) A palpable notch on the posterior border of the  hard palate.   (b) Zona pellucida or a bluish tinge in the midline of the  soft palate due the paucity of muscle bulk at this level.   (c) Bifid uvula- this may extend from a mere groove  on the uvula to complete bifidity.   II. Complete cleft of the palate up to the incisive foramen   Ill. Unilateral complete cleft of the palate and pre-palate. In  these the vomer is attached to the maxilla on the non-cleft  side   IV. Complete bilateral cleft of the palate and pre-palate. These  patients have a protruding premaxilla, and the vomer is in the  midline    Victor Veau (1931) has classified cleft palates into four  groups [7] (Table 73.2)   include the submucous cleft palate and the occult submucous  in cleft palate.  Sommerlad has devised a grading system for the submucous  cleft palate with three points for each of the above criteria  [18]. A lesser score in this system naturally denotes more  trivial clefting. However, paradoxically a lower score reflects  a poorer prognosis for speech according to this study. An  occult submucous cleft does not exhibit any of Calnan’s cri-  teria but shows a trough-like depression on the superior sur-  face of the soft palate as seen in nasoendoscopy. Croft  believed that in these patients, the musculus uvulae is absent.  It is suspected when a child with a normal palate speaks with  nasal emission.    Fig. 73.6 (a, b) Picture of child with Pierre Robin Sequence    A routine per-oral examination of the neonate reveals the cleft  of the palate with or without cleft lip. The extent of clefting is  noted. General examination is mandatory as it is important to  identify syndromic patients. These are more common in iso-  lated cleft palate patients [19]. Pierre Robin sequence is a  fairly common presentation with micrognathia or retrogna-  thia (Fig. 73.6 and b). As the bony abnormalities are believed  to be the cause of the non-descent of the tongue in utero lead-  ing to the clefting of the palate, this is now believed to be a  sequence and not a syndrome. Syndromic patients include  Treacher Collins syndrome, Goldenhar syndrome, etc.    The first clinical visit usually happens soon after birth. The  extent cleft is assessed, i.e., the length of the palate and the    width of the cleft. Randall has classified cleft palate on the  basis of length into four types [20]. Clefts may be partial or  complete. A partial cleft of the secondary palate is confined  to the soft palate (Fig. 73.7).   A complete cleft includes both the soft and the hard palate  up to the incisive foramen (Fig. 73.8). In patients with bilat-  eral cleft lips, the associated cleft palate usually presents  with a central vomer and clefting on either side of the vomer  (Fig. 73.9).   A pediatric assessment is made for other anomalies,  weight of the baby is noted, and feeding instructions are  given during this visit. A squeezable feeding bottle is usually  advisable to overcome child’s difficulties in sucking. The  child is fed with the head held slightly higher. Parents are  counselled about the need for immunization. They are also  explained about the need for surgery and are shown results of  the procedure on similar patients. It is very important to allay  their anxiety as they are very often crestfallen on seeing the  deformity in their baby. Subsequent visits, possibly at  monthly intervals, aim to assess the growth and development  of the baby. Associated cardiac or other anomalies if present  need investigation.    Routine imaging is not generally practiced in the evaluation  of cleft palate patients. Syndromic patients require other  investigations as part of the various manifestations of their  syndromes. For instance, children with velocardiofacial syn-  drome may require echocardiogram in view of the associated  cardiac anomalies. Children with delayed development,  microcephaly, etc. will require neurological assessment and  will usually need an MRI of the brain. Rarely a child may  have a meningoencephalocele presenting behind the palate.  MRI has been used to evaluate submucous clefts with a view  to help in the planning of the management. If it can be shown  that there is not adequate muscle continuity across the mid-  line, an early decision can be taken to operate on the child at  the usual time of cleft palate repair. On the other hand, if  there is good muscle across the midline, these repairs can be    justifiably delayed until the development of speech. MRI has  also been used to assess the Eustachian tube function.  Hearing assessment should be mandatory in all cleft palate  patients.   The dilemma regarding the timing of repair is between  earlier repair with better prognosis for speech, but worse  prognosis for maxillary growth, and late repair which is  exactly the opposite. Most surgeons today agree that the  cleft palate is to be operated close to | year. Some prefer  9 months, where others wait for up to a year and 4 months.  At our center we have been operating on these children at  about 11 months of age. The Oslo school of surgeons [21,  22] devised a protocol of operating on the lip with the soft  palate in the first stage and operating on the hard palate  much later. In some centers, the palate has been repaired    first at initial presentation, and the cleft lip is repaired, sub-  sequently, in view of the fact the children may not be  brought back for treatment of the palate once the lip is  repaired [23].   Airway management is important at the time of birth  in cleft palate patients, as most of isolated cleft palates  may be associated with a smaller airway at birth. This  may be due to associated sequence or syndromes, such  Pierre Robin sequence or Treacher Collins syndrome.  Such patients might require emergency tracheostomy or  tongue lip adhesion to secure airway. Definitive manage-  ment for mandibular advancement and cleft palate repair  can be undertaken at a later stage.   As mentioned already, the parents are counselled about  feeding practices during the first visit itself. Expressed  breast milk is to be preferred. Special feeding bottles like  the Haberman feeding bottle are used when the common  methods like the use of simple squeezable bottles are not  effective. As a cleft child swallows air along with the  milk, frequent burping is essential to avoid regurgitation  of feeds.   The operation is performed under general anesthesia  with an endotracheal tube. RAE tubes are preferred for  cleft palate patients. Previously, Oxford red rubber tubes  were used. These were well adapted to the needs of the  cleft children but often caused laryngeal edema presum-  ably due to the latex in the tubes. At our center we have  given up the use of these otherwise very useful tubes.   Preoperatively, the child must be assessed by a good  pediatrician and also by a senior anesthetist. Respiratory  infections are common in these children and must be  treated if significant. X-ray of the chest is usually done to  rule out heart or lung anomalies. Cardiology clearance is  required when there are suspected cardiac anomalies. We  have come across one case with a congenital absence of  the lung.   The anesthetist should be experienced in pediatric  anesthesia. In patients with Pierre Robin sequence or  other anomalies like shoulder or spinal anomalies, dif-  ficult intubation is to be anticipated, and appropriate  equipment such as intubating endoscopes, etc. should be  at hand, and the anesthetist must be familiar with its use.    There are various surgical techniques described in litera-  ture. The techniques have been mentioned (Box 73.2), with  the author’s surgical technique described in detail (Figs.  73.23, fa.24, 73.25, 73,26, 73,27, 73.28, 13.29, 73.30, and  73.31).   e Repositioning of the abnormal position of the mus-  cles of the soft palate.   e Favorable retro positioning of the soft palate and  uvula so as to achieve velopharyngeal closure dur-  ing speech.    73.7. Surgical Technique (Figs. 73.12, 73.13,  73.14, 73.15, 73.16, 73.17, 73.18, 73:19,  73.20, 73.21, 73.22, 73.23, 73.24, 73,25,  73.26, 73.27, and 73.28)    Once intubated, the child is placed with the neck extended for  adequate visualization of the palate. A pillow under the shoul-  der helps in this positioning. A suitable mouth gag is used. We  use the Dott’s gag (Fig. 73.12) with the Kilner suture carrier.  A popular gag used widely is the Dingman’s gag.  Infiltration: A solution of lignocaine with | in 200,000  adrenaline is infiltrated under the mucoperiostem of the hard    Fig. 73.10 Langenbeck procedure. Incisions are placed to raise flaps  which remain attached in the anterior palatal region    palate and above the nasal mucosa in the soft palate. A dental  syringe with a short-beveled needle is very useful for this  purpose.   Surgical procedure: At our center, we use the two long-  flap technique popularized in India by Charles Pinto and  the world over by Bardach (Fig. 73.13). The technique was  originally used by Veau. The cleft edges are pared  (Fig. 73.14).   The lateral incision is made from the maxillary tuberosity  area toward the retromolar area posteriorly. The pterygoid  hamulus is dissected, fractured, and detached (Fig. 73.15a  and b).   This aids in mobilization of the nasal layer subse-  quently. However, there are many surgeons nowadays    Fig. 73.13 Pinto Wardill (Bardach) two long-flap procedure. Classical  method of raising two flaps detached at the anterior pedicled on the  greater palatine artery    who do not believe in fracturing the hamulus. It has, how-  ever, been shown in different studies that fracture of the  hamulus does not cause any deleterious effects on hear-  ing [26].   The lateral incision is then carried anteriorly and the  oral mucoperiosteal flap is lifted off till the medial edge of  the hard palate using Kilner’s palate elevators (Fig. 73.16a  and b).    An incision is then made on the medial border of the hard  palate, and the flap is also divided anteriorly taking care to  secure the end of the greater palatine vessels. The oral flap is  then raised till the posterior border of the hard palate.  Laterally, the greater palatine vessel is identified and skele-  tonized, after incising the cone of periosteum which binds  the vessel behind it (Fig. 73.17a, b, c and d).    After the hamulus is fractured, the medial pterygoid plate  is denuded of any soft tissue attachments (Fig. 73.18).   Similarly, the posterior border of the hard palate is also  cleared of muscular attachments (Fig. 73.19a and b).   A Cumine Scaler is introduced over the bare medial pter-  ygoid plate and then turned anteriorly to separate the nasal  layer from the hard palate in one clean sweep. This dissec-  tion is then completed on a deeper plane with a Wallace’s  finisher (Fig. 73.20a and b).   This practice of separating the nasal layer from behind  forward was originally introduced by Kilner [8] but has  somehow not been followed widely. It is much easier than  the alternative method of separating the nasal layer from the  hard palate starting anteriorly. Very often this results in tear-  ing of the nasal layer.   Similar dissection is performed on the other side also,  raising a long oral mucoperiosteal flap. The vomer flap is  raised (Fig. 73.21) and used when accessible and  necessary.   Rarely, the vomer is receding and cannot be used. In a  bilateral cleft lip patient, the vomer is in the midline, and a  central incision on the vomer is made to raise two mucoperi-  osteal flaps, one on each side, to be sutured to the corre-  sponding side in nasal layer of the hard palate.    Fig. 73.16 (a, b) Elevation of the oral flap with Kilner’s elevator    The early techniques of cleft palate repair only detached all  false attachments of muscles from the posterior border of the  hard palate (Fig. 73.22).   Surgeons like Braithwaite [27] and Kriens [28] empha-  sized the importance of the dissection and retroposition of  the levator veli palati muscle. This was popularized by  Sommerlad [29] and Tambewekar in India.   Infiltration of lignocaine with 1:200,000 adrenaline is  made between the nasal mucosa and the muscle (Fig. 73.23).   A transverse incision is made on the aponeurotic layer  just beyond the hard palate (Fig. 73.24).   Then the muscle is dissected off the underlying mucosa  leaving behind enough tissue on the nasal layer, to avoid its  tearing during suturing. Also, a narrow layer of muscle is  retained along the cleft edges to hold the sutures. The muscle  is dissected till just short of the uvula. The muscle contains  the levator veli palati mostly. However, it also contains other  muscles like the palatopharyngeus (“muscle of Veau’)  (Fig. 73.25).   The extent of dissection of the muscle on the soft palate  varies. The authors [30] only separate it from the nasal layer.  Others like Sommerlad [29] also separate it off the oral layer.  However, if there is any suspicion of injury to the greater  palatine vessels during dissection, then the levator muscle  should not be dissected free of the oral mucosa.    Suturing commences on the nasal layer from anteriorly, pro-  ceeding backward. The sutures are not tied but held on the  Kilner suture carrier.    73.7.2.1_ Uvula  The last suture on the nasal layer is a mattress suture  (Fig. 73.26) [30].   Next, an apical mattress suture is placed on the tip of the  uvula, and this suture is left long and held on an artery for-  ceps, thus turning the uvula over, providing access to the  nasopharyngeal aspect of the uvula. Two or three simple  sutures are placed between the mattress suture and the apical  stitch (Fig. 73.27a).   Then two or three mattress sutures are placed on the oral  aspect of the uvula (Fig. 73.27b).   “A” suture: this is the suture placed at the junction of the  hard and soft palate. It goes through the nasal mucosa and  later crisscrosses into the oral mucosa, resembling the letter  A, but is like the figure of “8” when tied.   Suturing of the oral layers then proceeds from behind  forward, with every suture picking up a bite on the nasal  layer to obliterate dead space. The dissected levator mus-    Fig. 73.17 (a,b) Incising the Periosteal cone to free the greater palatine artery. (c, d) Hooking out the greater palatine vessels (the vessel is pulled  out like a bird pulls a worm out of the ground). This reduces the tension on the flaps on suturing    cle is also included in these oral sutures. Some surgeons  close the levator muscle as a separate layer. The anterior  sutures are then brought through the oral layer also, help-  ing in anchoring the oral layer. In the absence of the  anchoring, the oral layer may sag postoperatively causing  a “fallen palate.”   Laterally the raw areas are sutured with interrupted  sutures without tension. This helps in hemostasis (Fig. 73.28).   Previously, this area used to be packed with different  materials, but there was often bleeding from the areas on  removal of the pack postoperatively.   Buccal pad of fat harvested through a stab incision on the  buccal aspect bilaterally has also been used to fill large lat-  eral raw areas.   This is often from the apices of the long flaps, from the cut  ends of the greater palatine vessels. Arterial bleeding points  need to be ligated or cauterized using diathermy. Small  venous bleeding areas can be controlled by the use of pres-  sure with fingers or by the use of crushed ice or topical  hemostatic agents like tranexamic acid.   This may be from tongue fall and can be avoided by use of a  tongue stitch at the time of palate repair. The tongue stitch  has to be placed well posteriorly and must include a good  bulk of the tongue tissue to avoid the sutures from tearing  through.   When a wide cleft palate is closed, the child may have  difficulty in learning to breathe adequately through the  nose. Laryngeal edema due to endotracheal tube-related  trauma may present with a hoarse cry and, in severe cases,  chest retraction. Early detection is important, and this can  be reversed by intravenous steroids and nebulization.   It may result in fistulas or complete breakdown of the repair.  The most common cause of these, especially at the junctional  area, is suturing of the cleft edges under tension due to inad-  equate mobilization.    Fig. 73.19 (a, b) Dissection of the posterior end of the hard palate    Fig. 73.27 (a) Apical suture on uvula turned over and posterior sutures placed. (b) Completion of uvular reconstruction    Long-term complications include poor speech. Adequate  muscle repair has helped in better speech results. Nonetheless,  speech is an enigma that has not been adequately understood  and mastered. The variables like width of the cleft, the gap  between the uvula and the pharynx, and the adequacy of the  muscle repair all have a bearing on the speech results.  Despite all the advancements in the repair of the cleft palate,  no surgeon can truly claim to achieve perfect speech results  in all patients consistently.    The long-term evaluation of cleft palate patients should  include the presence or absence of a fistula, the quality of  speech, and the growth parameters of the maxilla, i.e.,  whether there is maxillary hypoplasia.    At present, many centers are able to produce fistula-free  palates in a majority of patients. Tension-free closure of the  palate and meticulous suturing are the key factors in the pre-  vention of fistulas. A review of literature reveals a huge  range in the incidence of fistula after cleft palate repair. The  range is from 2.6 to 58%. In between these extremes, many  have reported around 10%, some 15 and 23% [31, 32].   The emphasis on good levator veli palatini dissection and  repair has led to improved speech results overall. However,  one can never perfectly predict the speech outcome, as  speech itself is an enigma. Probably as a result of the varia-  tion in the presentation, mode of repairs and age at the time  of repair, etc., the published literature notes a VPI rate of  5.9-70% [32].   Maxillary growth continues to be a problem. Operations  like these of Robert Mann show promise in this direction.  Again, owing to variability involved in the type and extent of  cleft, the time of repair and the nature of the surgery, the need  for maxillary advancement may range from 10 to 40% in  non-syndromic cleft patients [32].    The age old saying that primary surgery is the best chance  for the surgeon to obtain optimal results is very apt in the  repair of the cleft palate. A badly repaired cleft palate  sometimes leaves behind a grossly scared palate with pau-  city of tissue. Small soft palate fistula can be repaired by  freshening of the edge and two-layered closure. Small hard  palate fistulas can be repaired by local turn over flaps for  lining and oral mucoperiosteal flaps for the oral layer.  Larger ones and those with poor speech will require revi-  sion palate repair. When there is gross deficiency of tissue,  flaps like the tongue flaps, or temporalis musculocutaneous  flap, facial artery muscle mucosal (Famm) flap may be nec-  essary [33, 34].   Secondary palate repair is also required for velopharyn-  geal incompetence (VPI). A detailed discussion about the  management of such incompetence is beyond the scope of  this chapter. Diagnosis of VPI is by speech assessment,  nasoendoscopy, or videofluoroscopy. Once a diagnosis is  made, treatment modalities will include redo palate repair,  sphincter pharyngoplasty, or flap pharyngoplasties, depend-  ing on whether it is the palate, lateral wall (palatopharyn-  geus) or the posterior wall, or a capacious pharynx as seen  on investigations.   Subsequent interventions will be required for maxillary  hypoplasia when significant. This is again out of the scope  of this chapter. In brief, anterior maxillary distraction is  done if the maxillary advancement required is significant  and the facial bones are still growing. Some of these do  require a LeFort | osteotomy later on if there is relapse.    When the growth is completed, then a LeFort 1 osteotomy  is required when there is significant maxillary hypoplasia.  When the advancement required is more than in | cm, bi-  jaw surgery is needed, with a LeFort 1 advancement in the  maxilla and a bilateral sagittal split osteotomy of the  mandible.    The use of the buccal mucosal flap in primary repair was  pioneered by Padgett [14] and then used extensively by  Murari Mukherjee [15]. Later Ian Jackson incorporated  buccinator muscle into the flap and used it on the nasal  layer transverse to provide for lengthening of the soft  palate.   Furlow’s Double Opposing Z plasty described by  Furlow [35] is increasingly used both for primary and  secondary repair of cleft palates. This illustrated in the  figure (Fig. 73.29a, b, c and d). Robert Mann has  described the extensive use of the double opposing “Z”  plasty with the buccal flaps over the nasal and/or oral lay-  ers to avoid lateral incisions and to promote for better  bony growth. This is probably the method of the future as  it shows promise of good speech and good maxillary  growth. However, extensive suturing of the buccal flaps  is involved and this is not the optimal surgery for the  novice to try. The Mann procedure is for the experienced  cleft surgeons [36].    This is a patient with a partial cleft of the secondary palate  (Fig. 73.30). The hard palate is intact. The cleft palate was  repaired at the age of 11 months using the Veau-Wardill  V-to-Y repair and radical muscle dissection in the soft palate.  Subsequently the child is undergoing regular follow-up and  speech assessment.    This is a child with a complete cleft of the primary and sec-  ondary palate on the (Fig. 73.31). The cleft lip was repaired  at 6 months of age using the Millard’s rotation advancement  technique. At 11 months, the cleft palate was repaired using  the two long-flap procedure popularized in India by Charles  Pinto, the mentor of the senior author, and, worldwide, by  Bardach. The child is now being subjected to constant fol-  low-up and speech therapy.    Fig. 73.29 (a, b) Furlow’s double opposing “Z” plasty (a) incision, (b) flaps raised and mucosal incisions placed, (c) double opposing Z plasty  completed and (d) oral flaps inset    . Holdsworth WG. Cleft lip and plate, vol. 82. London: William    tor. Cleft lip, palate and craniofacial anomalies, vol. 4. Philadelphia:  Saunders; 1990. p. 2723-4.    . Warren JM. Operations for fissures of the soft and hard palate. Am    . Kilner TP. Cleft lip and palate repair technique. St Thomas Hosp    . Wardill WEM. Techniques of operation for cleft palate. Br J Surg.    . Dorrance GM, Bransfield JW. The pushback operation for repair of    Grabb WC, Rosenstein SW, Bzoch KR, editors. Cleft lip and pal-  ate: surgical, dental, and speech aspects. Boston: Little, Brown And  Company; 1971.   Millard DR Cleft craft, vols. i, ii, iii. Boston: Little, Brown and  Company; 1976, 1977, 1980.   Thatte R, Govilkar P, Patel J. The tongue flap in the primary  treatment of cleft palate: a report of 19 cases. Br J Plast Surg.  1992;45(2): 150-4.   Padgett EC. The repair of cleft palates after unsuccessful opera-  tions. Arch Surg. 1930;20:453-72.   Mukherji MM. Cheek flap for short palates. Cleft Palate J.  1969;6:415-20.   Mann RJ, Fisher DM. Bilateral buccal flaps with double oppos-  ing z-plasty for wider palatal clefts, Plast Reconstr Surg. 1997  Oct;100(5):1139-1143; discussion 1144-5.  Calnan J. Submucous cleft palate.  1954;6(4):264-82.   Sommerlad BC, Fenn C, Harland K, Sell D, Birch MJ, Dave R,  Lees M, Barnett A. Submucous cleft palate: a grading system and  review of 40 consecutive submucous cleft palate repairs. Cleft  Palate Craniofac J. 2004 Mar;41(2):114-23.    Cohen MM. Syndromes with cleft lip and cleft palate. Cleft Palate  J. 1978;15:306-28.   Randall P, La Rossa D, McWilliams BJ, Cohen M, Solot C, Jawad  AF. Palatal length in cleft palate as a predictor of speech outcome.  Plast Reconstr Surg. 2000; 106:1254-9.    . Abyholm F. Primary closure of cleft lip and palate. In: Turvey TA,    KWL V, Fonseca RJ, editors. Facial clefts and craniosynostosis.  Philadelphia: WB Saunders; 1996. p. 370e383.   Friede H, Lilja J, Lohmander A. Long term, longitudinal fol-  low up of individuals with UCLP after the Gothenburg pri-  mary early veloplasty and delayed hard palate closure protocol:  maxillofacial growth outcome. Cleft Palate Craniofac J. 2012  Nov;49(6):649-56.   Agrawal K, Panda K ,A modified surgical schedule for primary  management of cleft lip and palate in developing countries.  Agrawal K, Panda K. Cleft Palate Craniofac. J. 2011;48(1):1-8.  Peet E. The Oxford technique of cleft palate repair. Plast Reconstr  Surg Bull. 1961;28:282-94.   Lehman JA Jr, Douglas BK, Ho WC, Husami TW. One-stage closure  of the entire primary palate. Plast Reconstr Surg. 1990;86:675-81.  Kane AA, Lo LJ, Yen BD, Chen YR, Noordhoff MS. The effect  of hamulus fracture on the outcome of palatoplasty: a preliminary  report of a prospective, alternating study. Cleft Palate Craniofac J.  2000 Sep;5:506-11.    . Braithwaite F, Maurice DG. The importance of the levator palatini    muscle in cleft palate closure. Br J Plast Surg. 1968;21:60-2.  Kriens OB. Anatomy of velopharyngeal area in cleft palate. Clin  Plast Surg. 1975;2:261.   Sommerlad BC. A technique for cleft palate repair. Plast Reconstr  Surg. 2003 Nov;112(6):1542-8.   Adenwalla HS, Narayanan PV. Primary cleft palate repair, surgical  correction, facial deformity varghese mani. Kochi: Jaypee; 2010.  Lindsay WK, Witzel MA. Cleft palate repair: Von Langenbeck  technique. In: Bardach J, Morris HL, editors. Multidisciplinary  management of cleft lip and palate. Philadelphia: W.B. Saunders  Company; 1990. p. 303.   Pomerantz JH, Hoffmann WM. In: Nelegan P, editor. Chapter 23  cleft palates in plastic surgery. 4th ed. Philadelphia: Elsevier; 2010.  p. 579.   Gue-Santos J, Altamirano JT. The use of lingual flaps in repair of  fistulas of the hard palate. Plast Reconstr Surg. 1966;38(2):123-8.  Pribaz J, Stephens W. Crespol, Gifford G. a new intraoral facial  artery musculomucosal (Famm) flap. Plast Reconstr Surg.  1992;90(3):421-9.   Furlow LT Jr. Cleft palate repair by double opposing Z-plasty. Plast  Recostr Surg. 1986;78:724-38.   Mann RJ, Martin MD, Eichhorn MG, Neaman KC, Sierzant CG,  Polley JW, Girotto JA. The double opposing z-plasty plus or minus  buccal flap approach for repair of cleft palate: a review of 505 con-  secutive cases. Plast Reconstr Surg. 2017 Mar;139(3):735e44e.    Open Access This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.  org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropri-  ate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.    The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in    a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.   Attempts to graft the alveolus started in the early 1900. The  rationale for the procedure however has changed over the  period. From its use as a procedure for establishing continu-  ity over a defect, it has evolved and made itself indispensable  in both cleft-related orthodontics and orthognathic surgery.  Over the years, the technique has evolved, and the materials  used have also been constantly studied and improved upon.  This chapter aims to elaborate on the morphology of the  alveolar cleft, its implications on dentition as well as facial  skeleton, and the various management strategies and evolv-  ing trends.    The alveolar process is that part of the jaw that contains the  tooth sockets and forms a bridge between the teeth and the  basal bones. The alveolar process is present in both the max-  illa and the mandible. The status of the alveolar process and  its development depends on the status of the teeth; if the  teeth are absent or lost in later life, it reduces in size, eventu-  ally disappearing completely.    The alveolar process begins to form in the end of the second  month of fetal life. The maxilla and mandible develop a  groove-like structure that opens toward the surface of the  oral cavity. This groove contains the tooth germs, the dental  nerves, and vessels. Gradually, bony septa begin to develop  between adjacent tooth germs. Later the primitive mandibu-    V. Muthusubramanian (J) - K. M. Harish  Department of Oral and Maxillofacial Surgery, Ragas Dental  College, Uthandi, Chennai, India    © The Association of Oral and Maxillofacial Surgeons of India 2021    lar canal is separated from the dental crypts through a hori-  zontal plate of bone. The alveolar process remains fused to  the body of the maxilla and mandible, and its formation is  completed during tooth eruption.    There is no distinct boundary between the body of the max-  illa or mandible and their corresponding alveolar processes.  In conditions where the alveolus is not functionally related to  teeth, it may be fused with and partly masked by bone.    1. Alveolar bone proper: It consists of a thin lamella of bone  which surrounds the root of the tooth and gives attach-  ment to the periodontal membrane.   2. Supporting bone: It is the structure which surrounds the  alveolar bone and gives support to the socket. The latter,  in turn, consists of two parts.   (i) The compact bone/cortical plate forming the vestibu-  lar and oral plates of the alveolar processes.   (ii) The spongy bone between these plates and the alveo-  lar bone proper.    The cortical plates are usually much thinner in the maxilla  than in the mandible. They are thickest in the bicuspid and  molar region of the mandible especially on the buccal side.  In the maxilla, the outer cortical plate is perforated by many  small openings through which blood and lymph vessels pass.  In the mandible, the cortical bone of the alveolar process is  dense and, occasionally, shows small foramina. In the region  of the anterior teeth of both jaws, the supporting bone is, usu-  ally, very thin. No spongy bone is found here and the cortical  plate is fused with the alveolar bone proper.   The interdental and interradicular septa contain the perfo-  rating canals of Zuckerkandl and Hirschfeld, which house    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1 -15-1346-6_74    the interdental and interradicular arteries, veins, lymph  vessels, and nerves. The alveolar bone proper which forms  the inner wall of the socket contains many openings which  transmit branches of the interalveolar nerves and blood ves-  sels into the periodontal membrane. It is named cribriform  plate or lamina dura.    The primary functions of the alveolar bone are highlighted in  (Box 74.1).    The alveolar cleft is usually represented either by a notch in  the alveolus on the labial aspect or as a complete gap between  the alveolar segments. In unilateral alveolar clefts, the cleft  side of the maxilla (referred to as the lesser segment) is  underdeveloped, causing abnormalities of the alveolus, as  well as the lip, nose, and palate.    The abnormalities of the alveolus and the dentition are pro-  jected in (Box 74.2).    e The pyriform rim on the cleft side, when viewed sagit-  tally, appears retrusive.   ¢ The nasal floor is displaced inferiorly, and there is trans-  verse constriction of the anterior bony nasal aperture.   2. Attachment: It gives the attachment for periodontal  ligament fibers, which are the principle fibers.  These fibers which enter into the bone are called as  Sharpey’s fibers.   3. Support: It supports tooth roots on the facial and the  palatal/lingual sides.   4. Shock absorber: It helps to absorb forces placed  upon the tooth by disseminating the force to under-  lying basal bones.   e The position of the premaxilla may be altered with  the arch being normal or rotated toward the non-  cleft side. There is change in the position of the  premaxilla.   e The central incisor is usually rotated toward the  cleft side (Fig. 74.1b).   e The lateral incisor may be congenitally absent or  hypoplastic or at times resemble a supernumerary  tooth. It may also protrude through the nasal floor  and lie within the cleft (Fig. 74.1c).   e The periodontal attachments of the central incisor  and canine on the cleft side are poor and have high  risk of future bone loss.    Fig. 74.1 Intraoral frontal picture demonstrating clinical features of  cleft alveolus (left side). (Refer to Box 74.2 for description of a, b and c)    ¢ The medial crus of the nasal cartilage is short, and the  upper and lower lateral cartilages do not overlap. There is a  mismatch in the level of lower lateral cartilages (Fig. 74.2a).   ¢ The columella, caudal septum, and anterior nasal spine  tend to deviate to the non-cleft side.   ¢ The above factors result in lack of support for the external  nose, especially around the alar base, which is displaced  laterally, inferiorly, and posteriorly, widening the nasal  aperture (Fig. 74.2b).   ¢ The fibers of the orbicularis oris muscle do not run trans-  versely and instead turn upward along the margins of the  cleft, to terminate beneath the base of the columella medi-  ally and below the alar base and periosteum of the pyri-  form rim laterally. Due to the abnormal muscle attachment,  there will be a bulge on the unrepaired cleft lip, distortion  of the ala of the nose, and deflection of the nasal septum  and anterior nasal spine.    Fig. 74.2 Basal view picture demonstrating abnormalities of the  lip-nasal complex (a) mismatch of the lower lateral cartilages and (b)  widening of the nostril due to lack of support for the cleft side alar base   5. Increase the cleft width in preparation to receive the  graft.    74.4 Role of the Orthodontist in Patients  with Alveolar Cleft (Box 74.3)    The objective of alveolar bone grafting (ABG) primarily  involves restoring the structural and functional integrity  of maxillary alveolar arch. This would further facilitate  the eruption of the canine or lateral incisor into their  respective position in the maxillary alveolar arch. The fur-  ther employment of orthodontic treatment would help in  stabilizing the arches and achieving proper alignment of  misaligned teeth, The aim of orthodontics in ABG are  highlighted in Box 74.3.   The orthodontist must be involved at all stages of dental  development, namely, infancy, primary, mixed dentitions,  and the permanent dentition stages.    1. Pre-surgical orthopedics can be done with the use of  appliances such as Latham’s appliance, etc. It consists of  a pin-retained device that is inserted into the palate with    acrylic extensions onto the alveolar ridges. Further a  screw mechanism is then used to manipulate the segments  as desired.   2. Primary bone grafting is also an option, which is done in  some cases, as it was believed that defect, which when  corrected earlier, would allow normal development and  function. However, it remains controversial, as there are  no important benefits compared to secondary bone graft-  ing done. In addition, scarring can cause deleterious  effects and retard growth.   3. Gingivoperioplasty can also be done to improve the clo-  sure. It involves creation of a mucoperiosteal bridge  across alveolar cleft region, thus creating a subperiosteal  tunnel. This in turn facilitates bone generation.   In case of untreated clefts, the maxillary development  was found to be normal. Which indicates that early lip  repair may affect maxillary growth.   4. In case of a bilateral cleft repair, posterior alveolar seg-  ments behind the premaxilla are collapsed leading to a  protruded and superiorly positioned premaxilla.   5. Orthodontist’s role would be to reposition the maxilla and  expand the collapsed alveolar segments.   Jackscrew and spring-loaded appliance are some of the  orthopedic appliances used. However, the effect of these  appliances are still controversial.    1. Ina primary dentition, the orthodontist has no role to play  unless the children have crossbites.  2. Routine dental screening is advised to detect any caries.    1. Standard records for orthodontic diagnosis are procured  for the patient. Some of them being OPG, IOPA, and  occlusal radiographs.   2. Missing teeth, supernumerary teeth, and bone require-  ment are assessed with these radiographs.   3. Presence of posterior crossbite, malaligned upper inci-  sors, and bone defects at the cleft area are  documented.   4. Bone grafting should be done prior to any orthodontic  treatment, which is to prevent root exposure or peri-  odontal defects.   5. Arch expansion done should be limited if the patient is  supposed to undergo orthognathic surgery later.   6. The expansion is usually limited by the zygomatic but-  tress and scar tissue present.   7. The direction of the expansion, its extent, the presence  or absence of teeth, the resistance of tissue (which can    be high in scarring), surgical access to cleft area, and  compliance of the patient are factors that determine the  selection of appliance.   8. Spring appliances offer lighter forces with quad helix  providing better control in the expansion.   9. Any fistulae that are present in the patient should be cor-  rected during bone grafting.   10. In case of bilateral cleft, the mobile premaxilla is stabi-  lized by grafting, and orthodontic treatment is started  only after the bony union is complete, which may be a  range between 2 and 6 months.   11. Orthopedic appliances like headgears can be given to  patients with mild maxillary deficiencies.   12. Distraction osteogenesis or orthognathic surgery  should be chosen depending on the patient’s growth  status (refer Chap. 69 on maxillary orthognathic sur-  geries, Chap. 75 on cleft maxillary hypoplasia and  Chap. 87 on distraction osteogenesis).   2. Most common problems which are seen are missing or  malformed teeth.   3. Sometimes teeth may be present but compromised. Most  often it is the lateral incisor. One must decide whether this  has to be treated with canine substitution or prosthetic  replacement.   4. In cases where there is (1) deviation of the dental midline  toward the non-cleft side, with the canine erupted mesi-  ally with favorable root position, or (ii) the canine is small  and wide with both premolars present on the cleft side,  and the molar and canine relationships on same side are  class Ul, the right choice of treatment would be canine  substitution. It involves extraction of the malformed lat-  eral incisor with poor periodontal support, followed by  facilitating the eruption of canine in the place of lateral  incisor.   5. In cases in which both the maxillary canine and the first  molar have a class I relationship, or the canine is posi-  tioned with the crown mesially and root distally, with a  shift of the maxillary midline to the cleft side, prosthetic  replacement is ideal. Adequate space should be planned  to accommodate the prosthesis.   6. Comprehensive orthodontic treatment starts almost a year  or 2 prior to surgery.   7. Dental decompensation for cleft maxillary osteotomy  surgery must be planned and executed. Surgical prepara-  tion should include wire placements, retentive hooks for  IMF, and plans for post-surgical retention.   8. If relapse is noticed post-surgically, it is immediately  addressed with class III elastics or a reverse pull  headgear.    V. Muthusubramanian and K. M. Harish  74.5 Alveolar Bone Grafting Procedure    Attempts to graft the alveolus started in the early 1900s.  In the beginning, the goal was to prevent collapse of the  alveolar ridge. Therefore, it was done during infancy. In  1970, reconstructive surgeons like Boyne [2, 3] stated  that the ideal age for grafting the cleft was between 9  and 11 years. This was done to allow eruption of the  canine.    Alveolar bone grafting procedures are classified into four  types based on the age and timing of the procedure:    ¢ Primary—This is performed in infancy, with the patient  being below 2 years of age. This is done following lip  repair but before the palate is repaired.   ¢ Early secondary—This is done between 2 and 5 years of  age, prior to the eruption of incisors.   ¢ Secondary—Performed between 8 and 11 years of  age, prior to eruption of the maxillary permanent  canine.    The advantages and disadvantages of the various methods  are highlighted in Table 74.1.    A variety of materials have been used in grafting in second-  ary cleft deformities.   The success rate differs for each type, but fresh autolo-  gous cancellous bone is considered to be superior because it  allows cells that are immune-compatible and integrate fully  into the maxilla and trigger osteogenesis. In addition, it is the  only bone source which possesses all the properties that pro-  mote bone formation—osteogenesis, osteo-conduction, and  osteo-induction.  74.5.3.1_ Bone Grafts  ¢ Cortical:    74.5.3.2  Autogenous Materials  The following sites are commonly used as sources for autog-  enous material used in alveolar bone grafting:    e The cranium, or calvarial bone, is a source of both cor-  tical and cancellous bone.   ¢ This site is associated with low morbidity and mini-  mum postoperative pain.   e Scar will be unseen within the hair with early dis-  charge and good prognosis.   ¢ Jt has poor outcomes as compared to iliac crest bone.    ABG techniques  Procedure Advantage Disadvantage  Primary Limited dissection. Alveolar segments  grafting Reduced maxillary growth _ have to be aligned  discrepancy orthopedically.  Requires additional  surgeries.  Reduced success rates  [4]  Early Possibly could facilitate Not accepted widely in  secondary eruption of lateral incisor as _ literature [4]  grafting well  Secondary Minimal influence in Earlier intervention  grafting maxillary growth as most of _ could result in eruption  the maxillary growth is of lateral incisors as  completed by 6-7 years [4]. well  Sufficient quantity of bone at  donor site is available.  Better patient cooperation.  Orthodontic treatment  acceptance is good.  Allows eruption of  permanent teeth through the  graft, thus maintaining good  periodontal health  Late No significant advantage. Less success rate.  secondary Mandibular symphysis could Loss of osseous  grafting be considered as good donor — support to teeth    cess. Therefore, this graft generally resorbs and is  replaced by invasion of bone cells originating from the  recipient site. The rate of metabolic turnover and corti-  cal bone remodeling is much slower than in cancellous  bone. Therefore, keeping the tooth-bearing function in  mind, cortical grafts may not be feasible for the alveolar  process.   Cancellous bone refers to the softer trabecular bone that is  more vascular. This allows better ingrowth from the recip-  ient site. The formation of new bone starts at the surface  of the existing cancellous bone. Cancellous bone theoreti-  cally heals by osteogenesis, followed by bone resorption  and deposition. This graft is harvested as a particulate  form, so it may be difficult to stabilize it in the recipient  site.   A combination of the two produces good results and  enables good vascularization to help incorporate bone  with surrounding structures. It also adds good mechanical  strength.   e It has huge quantity of cancellous bone which aid  osteogenesis. The process of condensing bone chips  into the defect increases the reliability of this bone.   ¢ Bone from this region may be harvested using a tre-  phine or through an open approach.   ¢ Approach needs to be planned well as it may leave an  unacceptable scar.   ¢ The main disadvantage of using iliac crest is postop-  erative pain, which may require extended hospitaliza-  tion, which can be surmounted by regional anesthetic  techniques for post-surgical pain control.   ¢ This is the most preferred donor site and is used by  87% of European surgeons and 83% of North American  surgeons performing ABGs [6].   ¢ Bone provided is more cortical and is limited com-  pared to the ilium.   ¢ Damage to the adjacent teeth and mental nerve has  been reported.   ¢ There is minimal scarring, and patient may be mobi-  lized early but is restricted from sports for 3 weeks.   ¢ In children where the tibia is usually small, there is a  possibility of damage to the epiphyseal cartilage.   ¢ Used by 3% of European and 2% of North American  surgeons [8].   e This is rarely used, as it provides limited amount of  bone.   ¢ 0.5% of European and 3% of North American sur-  geons use this method [9].   ¢ Bone may also be harvested from the intermedullary  canal of the femur, but it carries the risk of high  morbidity.   Alloplastic materials that have been used for ABG include  rhBMP-2 (recombinant human bone morphogenetic pro-  tein), undecalicified freeze-dried bone, TEOM (tissue-  engineered osteogenic material), and bioglass.   e This is recombinant bone morphogenic protein,  with superior bone quality reported in BMP-2  group [10].   e Studies have shown that this material, when used  for ABG, had high chances of successful grafting  as is considered very effective in situations involv-  ing a larger bony defect, and does not demonstrate  any detrimental effect on neighboring anatomical  structures and no evidences of ectopic bone forma-  tion [11].   e This material contains MSC (mesenchymal stem  cells), PRP (platelet-rich plasma), human thrombin,  and mixed air.   e This commercially available material is made up of  silicone dioxide, sodium dioxide, calcium oxide, and  phosphorus pentoxide.    74.5.3.4 Allogenic Materials  These materials are comparable to autogenous materials and  allow for eruption of teeth while avoiding donor site morbid-  ity. However, they do not have osteogenic potential, which  causes delayed graft incorporation.    Most of the abovementioned products involve bone  obtained from genetically dissimilar individuals. These  allogenic bone particles are subjected to various pro-  cesses to ensure the allogenic graft material is devoid of  any microbial contamination however retaining the  organic matrix and the inorganic components. They are  available in various particle sizes or as block grafts or can  even be milled for specific patients using CAD CAM  technology.   ¢ To provide tension-free, watertight closure to retain  the graft and establish soft tissue continuity.   ¢ To pack adequate volume of graft in the defect and  restore bony continuity.   e Add stability to the maxilla as a single unit while  planning for orthognathic surgery.    The technique of alveolar bone grafting must be performed  with the following goals in mind (Box 74.4).   Alveolar bone grafting procedure is performed under gen-  eral anesthesia. It can be performed comfortably using both  naso-tracheal and oro-tracheal intubation. When iliac crest is  the chosen donor site, a two-team approach can be followed  simultaneously. The surgical sequence for unilateral ABG  (Figs. 74.3a-f and 74.4a—f) and bilateral ABG (Fig. 74.5) are  detailed below.   Surgery in the oral cavity is begun with infiltration of  local anesthesia containing adrenaline to assist hemostasis. It  has to be borne in mind that the reconstruction of cleft alveo-  lus involves neat and precise development of labial/palatal/  nasal layers and creating of a pocket for placement of graft,  as this will ensure creation of structural and functional integ-  rity of the alveolar arch. A fine needle gauge is used to probe  the bony edges of the cleft in order to identify the site of the  first incisions (Fig. 74.5b). The initial incision must be made  through the mucosa lying over the cleft and must pass down  to the bony margins (Fig. 74.3a, b). Try to preserve the soft  tissue on the labial and palatal sides. Adequate (and some-  times excess) tissue is usually present within the oronasal  fistula, which may be sacrificed after planning for the oral  layer closure. In the region of the pyriform aperture, there is  no bony margin. Hence, at this site the soft tissue is divided  to provide a layer for the superior most extent of the nasal  closure. A similar kind of division of the mucosa is necessary  on the palatal side too (Fig. 74.3c).   Next, incisions are made around the cervical region of the  teeth on the labial aspect of the alveolus. The incisions  should extend several teeth posteriorly from the cleft with  the exact distance determined by the width of the cleft. A  full-thickness mucoperiosteal dissection should be begun to  raise a large advancement flap. A similar procedure is carried  out on the palate, where incisions are made around the neck  of the teeth followed by full-thickness mucoperiosteal dis-  section. As an alternative oblique sliding flaps can also be  raised (Fig. 74.3a, b). As these dissections are proceeding,    Fig. 74.3 (a-f) (a and b) Incisions around the cleft margin and for  developing oblique sliding flaps (dashed lines), (c) Palatal flaps are  developed sharply with scissors. This also separates the nasal mucosa  from the palatal tissue. (d) Palatal closure. This can be done before or    after the nasal mucosa is closed. (e) Depiction of the nasal mucosal flap  along with the closure of the oral mucosa. (f) Nasal mucosal flaps are  reflected from the bony walls of the cleft. The palatal flap facilitates  packing and protects the palatal closure [4]    Fig. 74.4 (a-f). (a) Nasal flaps are approximated with sutures burying __ the palatal closure [4]. (d) Closure of the labial oblique sliding flap. (e)  the knots when possible. (b) The closure of the nasal mucosa and the — Final mucosal closure of the labial and palatal oblique sliding flaps. (f)  introduction of the bone graft to the alveolar defect. (¢) Bone is packed _A palatal splint placed over the closure area to prevent formation of a  into the defect with a periosteal elevator or orthodontic band pusher. hematoma and stabilize the bone graft    the bone graft. (e, f) Palatal depiction of the movement of the adjacent  mucosa in the oblique sliding flap technique. (g) Mucosal closure in a  bilateral alveolar cleft. (h and i) Final closure of the bilateral alveolar  cleft repair using an oblique sliding flap technique    Fig. 74.5 (a-i) (a) A bilateral alveolar cleft palate. (b) Needle palpa-  tion of the bony edges of the alveolar cleft while injecting local anesthe-  sia. (c) The incision line (dashed line). (d) Elevation of the nasal mucosa  on the left and closure of the nasal mucosa on the right. Placement of    Fig. 74.6 Pre-operative intra oral picture demonstrating collapsed  maxillary arches with hidden oro-nasal fistula    the periosteal elevator may be carried around the cleft to  allow the mucoperiosteum within the fistula to be rotated  superiorly. This allows the full extent of the bony cleft to be  visualized. Excess tissue within the nasal portion of the cleft    Fig. 74.7 Pre-operative intra-oral maxillary arch view of the same  patient in Fig. 74.6, providing good visualisation of the oro-nasal  fistula    can be trimmed, and then the nasal flaps are sutured to pro-  vide closure of the nasal floor. This helps in the closure of a  persistent oro-nasal fistula (Figs. 74.6, 74.7, and 74.8). It is  ideal to evert these flaps into the nose and to use inverted    Fig. 74.9 Clinical step in which a periosteal elevator is used to define  the alveolar cleft after closure of the nasal layer    Fig. 74.10 Creation of a pouch with closure of the labial flaps in the  alveolar cleft region to facilitate bone grafting    Fig. 74.11 Exposure of the iliac crest to harvest bone graft    sutures so that the knots are on the nasal side. One should  mobilize the palatal flaps toward the cleft (Fig. 74.8), utiliz-  ing releasing incisions if necessary. The palatal flaps may be  sutured using interrupted sutures (Figs. 74.9 and 74.10).   The harvested bone is then (Figs. 74.11 and 74.12) con-  densed into a syringe prior to placement and packed tightly  into the exposed bony cleft. While placing the bone graft, it  is important to establish a normal contour to the pyriform  aperture region. The labial flaps can be then advanced over  the graft. This usually requires the utilization of the  periosteal-releasing incisions made perpendicular to the  direction of the advancement. A tension-free closure is man-  datory for this technique (Fig. 74.13).   The two palatal and two labial flaps are then closed, utiliz-  ing a suture that simultaneously approximates all four cor-  ners. The final closure is completed with interrupted sutures  closing the labial flaps and the interdental releases (Fig. 74.14).  Closure is performed in a way that retains the attached gin-  giva overlying the reconstructed alveolus. Rarely, it may not  be possible to obtain adequate advancement of flaps which  necessitate the use of a cheek flap or a free gingival graft.    Fig. 74.13 Grafting of the alveolar cleft using harvested cancellous  bone from the iliac crest    The success of alveolar bone grafting depends on certain  outcomes, which include Box 74.5.   2. Adequate bone support that allows eruption of the  canine and support for adjacent teeth.    Several scales are used to assess the success based on the  above criteria. These scales use periapical, panoramic, or  occlusal radiographs. A few of these scales are given below:    ¢ Bergland scale [12] (Fig 74.15a—d).  This scale is the gold standard of assessment, and suc-  cess is judged based on the height of the post-graft inter-  dental bone septum. It is assessed after the eruption of  permanent canine. Four categories of success are  defined, with    Types I and II being satisfactory outcomes and Types  III and IV being unsatisfactory:   Type I: Interdental septum height is almost normal  (<25% of bone resorption).   Type IT: Interdental septum height is equal to or greater  than %4 of the normal height (bone resorption  25%-50%).   Type IIT: Interdental septum height is less than %4 of the  normal height (bone resorption 50%-75%).   Type IV: Bone graft failure; no continuous bony bridge  is visible across the cleft (bone resorption >75%)  (Fig. 74.15).    ¢ Chelsea scale [14] (Fig 74.16a-—f).  This scale evaluates the presence of bone in relation to the  teeth adjacent to the cleft. Based on this, six categories  have been identified. Only Types A and C represent satis-  factory outcomes.    Type A: Bone tissue is present at the cementoenamel  junction of the teeth adjacent to the cleft. At least 75%  of roots on either side are covered by bone.   Type B: Bone tissue is present at the cementoenamel  junction of the teeth adjacent to the cleft. At least 25%  of roots on either side are covered by bone.   Type C: Bone tissue is present and surrounds at least  75% of the roots on either side of the cleft, in an apical  direction.   Type D: Bone tissue surrounds at least 50% of roots on  either side of the cleft, with an apical to coronal  direction.   Type E: Bone tissue bridge is present in the cleft,  except in the apical and coronal directions.   Type F: Less than 25% of bone tissue is present around  both roots in the apical direction (Fig. 74.16).   These authors modified the Bergland scale described  above and used alphabets to describe success or  failure:   R (Regular): Bone graft is enough to allow for canine  eruption. However, tooth movement is deficient, or a  defect that is more than 25% of root length is seen.   B (Bad): Deficient bone in the nasal region, which does  not permit tooth movement.   This scale compares pre-operative and postoperative  occlusal radiographs, to assess the percentage of bone fill.  This also considers the eruption of the canine.    The complications of alveolar bone grafting may be wit-  nessed at the donor as well as the recipient site.    Fig. 74.16 (a—f) Chelsea scale [13]. (a) bone  present at the Amelo-cemental Junction (ACJ)  and covering 75% of both the roots, (b) bone  present at the ACJ covering atleast 25% of  both the roots, (c) bone covering atleast 75%  of both the roots from the apical direction,   (d) bone covering atleast 50% of the roots  from the apical direction, (e) bony bridge  present across cleft but no bone apically or  coronally and (f) less than 25% bone cover  from the apical direction   2. Graft resorption: Graft resorption signifies complete fail-  ure of ABG, which can occur due to the following  reasons:   (a) Osteoresorptive cells and an environment suitable for  bone resorption—this occurs with deciduous tooth  extraction.   (b) Excessive tension or trauma after surgery, resulting in  exposure and loss of the graft.   (c) Overpacking of the graft, causing alveolar notching  and graft resorption. (d) Poor oral hygiene.    Alveolar bone grafting aims at restoring the functional integ-  rity of the alveolar arch. In addition, they facilitate the erup-  tion of teeth through the grafted bone into their respective  positions. The timing of alveolar bone grafting is very cru-  cial and can be effectively assessed by evaluating the thick-  ness of bone covering the crown (of the lateral incisor or of  the canine), rather than the degree of root formation of these  teeth. The usage of autologous cancellous bone from the iliac  crest is the most widely accepted graft in the mixed dentition  period. In recent years, bone substitutes have also been used   e Hypoesthesia or anesthesia over the lateral  femoral cutaneous nerve and in its distribution  areas.    because of a tendency toward limited bone harvesting. These  allograft or alloplastic sources of bone graft are especially  useful in case of deficient donor autogenous bone material or  to minimize donor site morbidity or in complicated cases.  However, autologous bone is still the ideal choice for alveo-  lar bone grafting, and none of the currently available meth-  ods can replace autologous bone completely. The future  trend in alveolar bone grafting could be related to the usage  of stem cells for bone regeneration; however many long-term  clinical trials have to be conducted using stem cells to ensure  its wide usage and cost-effectiveness.    An 11-year-old female patient who was treated for unilateral  cleft lip and palate on the left side presented with the com-  plaint of leakage of fluid from the nose and escape of air  from the oral cavity. She had undergone primary unilateral  lip repair when she was 6 months old, and a palatal repair  was done when she was 2 years old.   Procedures, which were performed at this stage—fistula  closure and alveolar bone grafting.   A sulcular incision along with incision around the fistula  was performed both on the labial and palatal side so to enable  direct access to the fistula and bony defect. Oral and nasal  layers were separated. The nasal layer was initially closed in  a watertight manner. Cancellous bone graft was obtained  from the iliac crest, and the bone graft was placed into the  defect, and watertight closure was obtained.   Future treatment required—pre-surgical orthodontics,  orthognathic surgery, post-surgical orthodontics, and rhino-  plasty (if required).    Case Presentation  A 10-year-old female patient who was diagnosed with uni-  lateral cleft lip and alveolus on the left side (Fig. 74.19a, b)  reported to us with a chief complaint of leakage of fluid from  the nose. She had previously undergone primary lip repair at  8 months of age. An OPG and IOPA revealed the extent of  alveolar cleft (Fig. 74.19c, d). Pre-surgical orthodontic treat-  ment was started to align the teeth and facilitate the eruption  of 23 (Fig. 74.19e).   Procedures, which were performed at this stage—fistula  closure and alveolar bone grafting.   A sulcular incision was placed around the involved teeth  both on labial and palatal sides which exposed the fistula and    the alveolar defect. A careful dissection was performed so as  to separate the nasal layer and oral layer. The nasal layer was  initially closed in a watertight manner. An adequate quantity  of cancellous bone graft was harvested from the iliac crest.  Thus obtained bone graft was placed into the alveolar defect,  and a watertight closure was performed (Fig. 74.19f). The  alveolar bone graft was assessed 6 months post-surgery  using IOPA (Fig. 74.19g). The orthodontic treatment was  completed after facilitating the eruption of canine and  achieving leveling and alignment of teeth (Fig. 74.19h, i, j).    Future treatment required—Patient has to be assessed  after growth completion, and if required the following treat-  ment will have to be carried out:    Fig. 74.18 (a-f) (a) Extraoral frontal picture at rest. (b) Extraoral  frontal picture at smile. (c) Intraoral picture demonstrating fistula. (d)  Palate post-repair. (e) Creation of a pouch in the alveolar cleft region to    facilitate bone grafting. (f) Grafting of the alveolar cleft using harvested  cancellous bone from the iliac crest. (Fig. 74.14 shows Watertight clo-  sure of the alveolar cleft case shown in Fig. 74.18, after grafting)    Fig. 74.19 (a-—J) (a) Intraoral frontal picture demonstrating alveolar  cleft on the left side of maxilla and associated fistula. (b) Intraoral max-  illary occlusal picture demonstrating alveolar cleft and fistula. (¢) OPG  demonstrating the alveolar cleft on the left side and the eruptive status  of the upper left permanent canine. (d) IOPA demonstrating the pres-  ence of alveolar cleft between upper left central incisor and upper left  canine. (e) Intraoral frontal picture. Orthodontic treatment to facilitate  tooth alignment and eruption of permanent upper left canine. (f)  Intraoral picture demonstrating the completion of alveolar bone graft-    ing. (g) IOPA demonstrating the uptake of alveolar bone graft in the  region of alveolar cleft between upper left central incisor and upper left  canine. (h) Intraoral frontal picture demonstrating orthodontic treat-  ment. The permanent canine on the left side has been clinically moved  to the occlusal plane. (i) Intraoral maxillary occlusal photograph post-  orthodontic treatment demonstrating the eruption and alignment of  upper left canine in the alveolar arch. (j) Intraoral photograph post-  orthodontic treatment demonstrating the eruption and alignment of  upper left canine in the alveolar arch    . : ae 10. Hibi H, Yamada Y, Ueda M, Endo Y. Alveolar cleft osteoplasty  . Mccarthy JG, editor. Plastic surgery. vol 1, General principles. een : : : :  : : using tissue-engineered osteogenic material. Int J Oral Maxillofac  Philadelphia: Saunders. p. 77. Ak.  B Pi. Sanda NR. Combinsd oxkedond ical Surg. 2006;35:55 1-5.  oe eke ee ee eee, mae Bl g T, Tom WK, Carstens M. Repair of alveolar clefts with  ment of residualpalato-alveolar cleft defects. Am J Orthod 1976 : : F :  recombinant human bone morphogenetic protein (rhBMP-2) in  Jul;70(1):20-37. PubMed PMID:782258. : F : : :  : F patients with clefts. J Craniofac Surg. 2005;16(5):778-89.  . Boyne PJ, Sands NR. Secondary bone grafting of residual alveo- Be sesede .  12. Bergland O, Semb G, Abyholm F. Elimination of residual alveolar  lar and palatal clefts. J Oral Surg 1972 Feb;30(2):87-92. PubMed , : :  clefts by secondary bone grafting and subsequent orthodontic treat-  PMID: 4550446. Aas  P. sc aunties if Oral aud WEcailomeal h 43 ment. Cleft Palate J. 1986;23:175-205.  — § principles of Oral and Maxilotacial surgery, chapter 2, 13. Khalil W, De Musis C, Volpato L, Veiga KA, EMM V, Aranha  wey A. Clinical and radi hi ‘ t of dary b ft  . Deatherage J. Bone materials available for alveolar grafting. Oral sone gitar eae rn Te aih bee Moe  Maxillofac Surg Clin North Am. 2010 Aug:22(3):347-52. Sone Pe Ee eee j '  ye Me Genta BE Mon neltey a ane Nae ei Hence cite 14. Witherow H, Cox S, Jones E, Carr R, Waterhouse N. A new scale to  following bone grafting of the cleft alve. Br J Oral Maxillofac Surg. : ;  assess radiographic success of secondary alveolar bone grafts. Cleft  2006;44: 129-33. : ; :  E. KH J I. Bosch C. Mandibular b f ial Palate Craniofac J. 2002;39(3):255-60.  - Bnemark Fi, Jensen J, Bosch ©. Mancidular Done gratt materia’ 15 Trindade-Suedam IK, da Silva Filho OG, Carvalho RM, et al. Timing  for reconstruction of alveolar cleft defects: long-term results. Cleft : : : , :  : of alveolar bone grafting determines different outcomes in patients  Palate Craniofac J. 2001, March;38(2): 155-63. . : ets . : :  Huches CW. Revi PI. Th seep sdbiadl ite in clef with unilateral cleft palate. J Craniofac Surg. 2012;23(5):1283-6.  sri a ENED, Edy he VIO MOA ROHOE READ GEN 46 Fiadelati JD, Nashed RR, Bromige MR. Radiographic assessment    alveolar bone grafting: experience of 75 consecutive cases. J Cranio  Maxillofac Surg. 2002;30:12-6.   . Borstlap WA, Heidbuchel KLWM, Freihofe HPM, Kuijpers-  Jagtman AM. Early secondary bone grafting of alveolar cleft    of secondary alveolar bone grafting in cleft lip and palate patients.  Cleft Palate Craniofacial J. 1997;34:195-8.    Open Access This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.  org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropri-  ate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.   The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in  a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.    75.1 Introduction  Studies of adult patients with unoperated cleft lip and palate  (CLP) indicate that the maxilla in the unoperated patient is  normally positioned or protruded. There are two major fac-  tors contributing to the protruded maxilla. The first is the  absence of normal functional forces that are provided by the  perioral muscle and tissue continuity. The tongue pressure  pushes the teeth and the alveolus forward while the pressure  from the cleft lip and affected perioral tissues is insufficient  to balance this force out. The second factor contributing to  the prognathic maxilla is the missing surgical scar [1-3].  Studies comparing unoperated cleft lip cases versus those  with cleft lip repair show minimal difference in the growth of  the maxilla. Thus, it has been proven that cheiloplasty has  little effect on the growth of the maxilla and its dentition. On  the other hand, palatal surgery has been identified as the  main cause of inhibition of midface growth. Scar tissue  forms across sutural areas as a result of palatoplasty surgery.  This scar tissue interferes in the downward and forward  translation of the maxilla that plays a major role in normal  development. Furthermore, the scar tissue across the palate    Electronic Supplementary Material The online version of this chap-  ter (https://doi.org/10.1007/978-98 1-15-1346-6_75) contains supple-  mentary material, which is available to authorized users.    P. Mathew   Head of Department of Oral and Maxillofacial Surgery, Jubilee  Mission Medical College and Hospital, Thrissur, Kerala, India    Mustafa. K  Department of Craniofacial Surgery, Kanachur Institute of Medical  Sciences, Mangalore, Karnataka, India   Senior Resident cum Fellow of Orthognathic Surgery, Department  of Oral and Maxillofacial Surgery, Jubilee Mission Medical  College and Hospital, Thrissur, Kerala, India    © The Association of Oral and Maxillofacial Surgeons of India 2021    causes the constriction of the maxilla leading to a collapsed  bite or crossbite [1-3].   Maxillary hypoplasia is a secondary deformity that occurs  as a result of cleft lip and palate surgery with a reported inci-  dence of about 9-45% with isolated cleft lip cases having the  lowest incidence. The need for surgical correction of the  same can be identified as early as age 10. Factors frequently  associated with maxillary hypoplasia are congenitally miss-  ing maxillary teeth, revision palatoplasty procedures, pha-  ryngeal flaps, and delayed orthodontic care [4-7]. However,  recent evidence has suggested that presence of a pharyngeal  flap does not affect maxillary growth [8].    Cleft maxillary hypoplasia presents as a three-dimensional  deficiency. The degree of deficiency increases with the severity  of orofacial clefting and affects different anatomical subunits,  e.g., dentoalveolar, para-nasal, infra-orbital, and zygomatic  regions. The clinical features associated with cleft maxillary  hypoplasia are described in Boxes 75.1—75.3 [1-3, 7].   The presence of the cleft alveolus causes the dentoalveolar  segment to collapse palatally on the affected side(s) leading to  the creation of anterior and posterior crossbites. The failure to  perform an alveolar bone grafting and orthodontics during the  growing phase increases the severity of the malocclusion [9,  10]. The extent of this abnormal growth of the midface varies  from mild to severe and is also affected by genetic endowment,  the severity of clefting (extent of orofacial and labio-palatal  involvement), timing of surgery, surgeon skills, and the number  of primary and revision surgeries performed in the process of  re-habilitating the patient. It has not been conclusively proven if  any particular palate closure technique or if a staged technique  has reduced effects on maxillary growth. It is the author’s opin-  ion that techniques that leave a raw area on the palate like push-  back palatoplasty are generally associated with greater maxillary  regression [1—3, 11-15].    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1-15-1346-6_75   e Short upper lip and Acute nasolabial angle [subject  to variability],    Box 75.2: Secondary Residual Deformities in Cleft Lip  and Palate Patients   — Obstructive nasal breathing (septum deformity/  enlarged inferior turbinates/intranasal strictures/  enlarged tonsils and adenoids/pharyngeal flaps)    — Delayed eruption of teeth, severe crowding of  arches (with impacted, malformed and supernumer-  ary teeth)   — Anomalous or missing lateral incisor, infra-erupted,  rotated, and tipped cleft-adjacent teeth    In most cases, photographic and cephalometric analysis  reveals that the mandibular plane-cranial base angle is  increased leading to a more backwardly placed mandible.  Thus, the mandible tends to have a mild retrognathic appear-    ance in spite of having normal dimensions. An anterior open  bite is observed if the patient has an underlying tongue thrust  habit as well. In certain rare cases, the chin and mandible may  also exhibit a degree of skeletal asymmetry [1—3] (Box 75.2).   The need for orthognathic surgery should be based not  only on occlusion and jaw relationship but also on facial pro-  portions, midface projection, and complaints of the patient  [1-3].    Owing to the severity of the condition, period of orthodon-  tics can be prolonged and is carried out in three phases.  Sometimes patients with CLP have a limited ability to open  their mouth further increasing the difficulty of orthodontic  treatment.    Phase I Treatment It is carried out between 7 and 12 years  of age. Maxillary transverse expansion is carried out in cases    that present with maxillary constriction. Maxillary protrac-  tion may be carried out in cases with significant midface  regression. This phase also involves monitoring facial  growth, space management, monitoring eruption of perma-  nent teeth, and preventing ectopic eruption of permanent  teeth [1-3].    In preparation for secondary alveolar bone grafting,  extractions of supernumerary teeth and deciduous teeth on  either side of the cleft and closure of oronasal fistulae are  performed [16]. Box 75.6 outlines the controversy regarding  whether maxillary expansion should be performed before or  after alveolar bone grafting [17-19].    Box 75.6: Arch expansion, before or after Alveolar Bone  Grafting (ABG)   Greater expansion can be  achieved with the lower bony  resistance between the maxillary  segments   Nasal floor mucosa layer can be  easily visualized and  reconstructed as the cleft has been  widened    Expansion after ABG  Though expansion is  possible, the degree of  expansion obtained is less  predictable   Difficult to visualize and  reconstruct the nasal floor  mucosa layer as the cleft is  narrow   As the cleft is narrow at the  time of grafting, there is  lesser tension on the  overlying suture site after  grafting, which reduces the  risk of wound dehiscence  and graft failure  Decreased risk of loss of  periodontal support as the  teeth will move into an  already grafted cleft  alveolus    Widening of the cleft alveolus  leads to increased tension on the  overlying suture site after  grafting, which increases the risk  of wound dehiscence and graft  failure    Increased risk for cleft-adjacent  teeth moving into the cleft  alveolus while widening, thus  compromising their periodontal  support   Clinical studies have shown that  there is minimal risk for graft loss  when expansion was performed  before grafting    Clinical studies have shown  that bone graft was not lost  when expansion was  performed after grafting;  instead, some degree of  stimulation of graft took  place    Phase 2 (Presurgical phase) Treatment It is carried out  between 12 and 17 years of age. It involves maintaining the  previously attained expansion and further expanding the arch  in cases of relapse or if no prior expansion was done. In case  the skeletal discrepancy is minimal, we can also consider  camouflage orthodontics to correct the occlusal discrepancy.  Camouflage orthodontics involves correction of crowding  and rotations, extraction of teeth that have erupted ectopically    and cannot be accommodated, proclination of maxillary inci-  sors, and retraction of mandibular incisors.    In case the skeletal discrepancy is moderate to severe,  then we will have to consider surgical correction (distraction  osteogenesis or orthognathic surgery) of the deformity.  Presurgical fixed orthodontics is started to facilitate the  planned skeletal movements and is described in Box 75.7.    In case the lateral incisor is missing, the decision to main-  tain space for prosthetic rehabilitation or substitute it with  the adjacent canine needs to be made during this phase [1-3].  There is also a need to extract the mandibular third molars in  case a bilateral sagittal split osteotomy is planned. There is  an increased risk for bad splits associated with un-erupted  and impacted mandibular third molars in the age group of  less than 20 years on account of thinner and immature corti-  cal bone [20].    Phase 3 (Postsurgical Phase) Treatment It is performed  after surgical correction of the facial deformity (orthognathic  surgery or distraction osteogenesis). It involves fine-tuning  of the occlusion and maintaining achieved results in the long  term through retentive appliances. One may have to consider  re-creating dental compensations to accommodate for  increased rates of relapse after cleft-orthognathic surgery.    Facial growth is normally completed by 16 years of age in  females and by 17 years of age in males. It is advisable to  perform orthognathic surgery only after skeletal maturity is  achieved, in order to increase stability of the surgical results  in the long term. In selective cases, orthognathic surgery is  performed during growth for psychosocial or functional rea-    sons. However, this has shown unpredictable results because  of continued growth of the mandible with relapse rates in the  range of 50-70% when operated before 18 years of age [2,  21,22).   As an alternative, one may consider distraction osteogen-  esis prior to 17 years of age. A study by Meazzini et al. [23]  reported a relapse rate of 26% in the long term when distrac-  tion osteogenesis of the maxilla was carried out during the  growing phase. A systematic review by Liu et al. [24]  reported a relapse rate 12-46% at “point A” and 26-77% for  the SNA angle in the long term. Thus, the patient will require  additional surgery after skeletal maturity for correction of  the residual facial deformity, irrespective of whether distrac-  tion osteogenesis or orthognathic surgery was performed.    Patients with cleft lip and palate usually present with a cleft  alveolus. This cleft communicates with the nasal cavity, thus,  creating an oronasal fistula. The cleft is also a source of  weakness in the maxillary arch and increases the risk of arch  collapse, thus, creating dentoalveolar deformities (e.g.,  crossbites) which make later surgical procedures like orthog-  nathic surgery unstable. Lastly, the permanent teeth that  erupt into the cleft will have a poor prognosis due to lack of  bony support and inadequate periodontium. Thus, it is of  utmost importance to graft the cleft alveolar region, and the  benefits associated with it are described in Box 75.8 [9, 25].    Reduction of oronasal fistula, creation of continuity of  the maxillary alveolar arch, eruption of permanent  teeth into the cleft site, elevation of the alar nasal base,  and stability for future surgical procedures like orthog-  nathic surgery and rhinoplasty    A prerequisite to a successful alveolar bone grafting  is the closure of oronasal fistulae. Small fistulae can  be closed at the time of grafting. However, the pres-  ence of a large fistula requires a staged reconstruction  with the fistula closure initially and alveolar bone  grafting later.   It is not rare to see a patient with a complaint of maxillary  regression who presents at a later age (17 years and above)  with a history of no alveolar bone grafting or failed alveolar  bone grafting. If we proceed with a LeFort I osteotomy in  this clinical scenario, the difficulty of the surgical procedure  increases significantly as the maxilla is not a single unit.    1. The patient is willing to undergo a staged approach with  alveolar bone grafting followed by orthognathic surgery  at later stage. Though this is the ideal approach, it adds to  the cost and time of overall treatment. It is important to  note that tertiary alveolar bone grafting has an overall  lower success rate [26, 27].   2. The patient is willing to undergo alveolar bone grafting as  long as it is done simultaneously with orthognathic sur-  gery. This approach saves time and cost of overall treat-  ment. Keeping in mind that tertiary alveolar bone grafting  already has a lower success rate; it is the author’s opinion  that risk for graft failure might increase when this step is  combined with orthognathic surgery. This is on account  of the compromise in vascularity that occurs as extensive  mucoperisoteal flap refelction is performed to accomo-  date orthognathic surgery.   3. In case the patient wants to avoid bone grafting, one can  use the modified LeFort I osteotomy approach by Posnick  et al. [3, 28, 29]. It allows for simultaneous correction of  maxillary hypoplasia, cleft dental gaps, alveolar defects,  and small residual oronasal fistulas through the use of mod-  ified skeletal osteotomies. The cleft alveolar defect is  closed by differential repositioning of the cleft maxilla seg-  ments. This technique requires a transverse plate to be  placed across the cleft site just below the pyriform aperture  so as to convert the cleft-maxilla into a single unit. In a  study by Posnick et al. [30], the modified LeFort I osteot-  omy technique had stable results in more than 90% of the  subjects at | year with a low complication rate. It is the  author’s opinion that along with the midline transverse  plate, one can also use a dental prosthesis (fixed partial  denture) spanning the cleft alveolus site to add stability to  the cleft maxilla. However, there is a risk for failure of the  prosthesis and loss of abutment teeth in the long term due  to increased movement across the cleft alveolus site.    If air or sound is allowed to leak through or resonate in the  nasal cavity during the production of the non-nasal sounds  (all phonemes except /m/, /n/, and /ng/), speech will be  marked by hyper-nasality (nasal twang) and nasal air emis-  sion. VPI describes a structural or anatomic defect that pre-  vents closure of the velopharyngeal mechanism during  function. It is most commonly observed in patients with an  overt cleft palate (unoperated > operated cases) and sub-  mucous cleft palate. In operated cleft palate patients, the  incidence of VPI can range between 20 and 50% [31]. Chua  et al. [32] and Pereira et al. [33] proposed the usage of per-  ceptual speech assessment, acoustic measurement with    nasometer, video nasoendoscopy (or video fluoroscopy), and  cephalometric analysis for the assessment of preoperative  speech and VPI.   When the maxilla is advanced in operated cases of the cleft  palate, speech articulation is improved on account of improved  lip competency and correction of previous dental malocclu-  sion [34, 35]. There is also an associated increase in the velo-  pharyngeal cavity depth [36]. As compared to the normal  palate, the scarred cleft palate has decreased ability to adapt to  such changes as it is unable to stretch adequately [37] This  leads to an increase in the risk for worsening of preoperative  VPI. The effect of maxillary advancement on VPI, especially  in cleft palate patients, is still a controversial topic [34, 38].   There are two methods that are commonly used to advance  the maxilla as given in Box 75.9.    1. Distraction osteogenesis: total maxillary distraction  and anterior maxillary distraction  (a) Total maxillary distraction: internal maxillary  distraction and rigid external distraction  2. Conventional orthognathic surgery    The theoretical advantage of distraction is that the maxilla  is advanced slowly which allows the patient to adapt to the  changes in the velopharyngeal dimensions through increased  velar muscle activity. Furthermore, distraction can be halted  at any point of time that speech begins to deteriorate.  Orthognathic surgery, unlike distraction, creates an immedi-  ate surgical advancement of the maxilla and does not allow  speech to be assessed incrementally or allow for gradual  adaption of the palate to the increase in the velopharyngeal  cavity depth.   A randomized controlled trial by Chua et al. [32] for mod-  erate maxillary advancement (4-10 mm) in cleft patients  demonstrated that distraction osteogenesis had no advantage  over orthognathic surgery for the purpose of preventing velo-  pharyngeal incompetence and_ speech disturbance.  Furthermore, no correlation was found between the amount  of advancement and speech parameters. However, it should  be noted that extreme advancements of the maxilla (greater  than 10 mm) were excluded from the study.   A study by McComb et al. [37] helped identify predictors  for worsening of VPI in cases of cleft maxillary advance-  ment using conventional orthognathic surgery. Short preop-  erative soft palate, large postoperative velopharyngeal cavity  depth, preoperative perceptual speech assessment, nasome-  try, and video nasoendoscopy were identified as clinically  significant predictors. Preoperative velopharyngeal cavity  depth was not considered a satisfactory predictor as changes  in the velopharyngeal space did not correspond proportion-  ally to maxillary advancement [39]. Lastly, the span of    maxillary advancement (2-16 mm) did not show a signifi-  cant association with the worsening of VPI [37].   Janulewicz et al. [35], Philips et al. [40], Alaluusua [41],  Smedberg [42], Seok-Kwun Kim et al. [43], Kelly Schultz  et al. [44], and Pereira et al. [33] studied the relation between  postoperative worsening of VPI and maxillary advancement  using conventional LeFort I osteotomy in cleft patients. They  established that preoperative borderline and higher grades of  VPI were highly prone to worsening in the postoperative  phase. Absent to negligible VPI pre-operatively, carries min-  imal risk of worsening during the post-operative period.  Furthermore, the amount of maxillary advancement and the  cleft type did not influence the degree of worsening of  VPI. In the author’s opinion, the only confounding factor in  the above studies was that some of the patients already had a  preoperative pharyngeal flap.   A study by Trindade et al. [45] suggested that deteriora-  tion in the VPI after orthognathic surgery was transient and  improved over time. Compensatory changes are known to  occur in the velopharyngeal region during that time as docu-  mented by the study of Yu Wu et al. [36]. The velar length  and angle and the velopharyngeal depth all increased.  However, velar thickness, posterior pharyngeal wall thick-  ness, and velar motility remained unchanged. During certain  phonations, the motion of the posterior pharyngeal wall and  the thickness of the Passavant’s ridge increased significantly.  Thus, it is advisable to wait for at least 1 year prior to consid-  ering surgical correction for VPI [35].   Poole et al. [46] and James et al. [47] suggested alterna-  tive surgical approaches to the routine LeFort I maxillary  advancement which involved transecting the palatal mucosa  followed by mobilizing the soft palate lying distal to the inci-  sion. This was combined with strategically placed vertical  incisions in the maxillary buccal mucosa to avoid circulation  injury. The advantage of the procedure was that the maxilla  could be advanced by large amounts without worsening of  speech and VPI as the soft palate did not move anteriorly  with the maxilla. The disadvantage of the procedure was that  a significant portion of the palate was left denuded and was  expected to heal secondarily. Though the results were prom-  ising, the techniques did not become mainstream.   Anterior maxillary distraction (AMD) is a versatile, stable,  and simple technique that can be used to correct the maxillary  dentoalveolar regression in the cleft maxilla after the mixed  dentition phase (Video 75.1). As the osteotomy is anterior to  the junction of the hard and soft palate, the velopharyngeal  dimensions and soft palate activity are not affected. Thus, it is  considered optimal for the correction of cleft maxillary regres-  sion in cases with preoperative moderate to severe VPI. When  used in the age group of 10-16 years, there is also an associ-  ated posterior movement of the distal maxilla owing to the  elasticity of the bone which may also reduce preoperative VPI  to a certain extent. An added advantage is that the increased  arch length can be used to accommodate un-erupted teeth and  correct crowding [48-53].    In case postoperative VPI develops, it is advisable to wait  and watch for at least | year prior to resorting to surgical cor-  rection. During this period, one can try conservative methods  like speech therapy and bulb palatal lift prosthesis and mini-  mally invasive methods like autologous fat injections into the  soft palate and the posterior pharyngeal wall [31, 54, 55]. If  the VPI does not improve to a clinically acceptable level even  after a year, then surgical options need to be considered.   In terms of risk of development of postoperative obstruc-  tive sleep apnea, Furlow palatoplasty and buccal myo-  mucosal flaps have the least adverse effect followed by  sphincter pharyngoplasty and finally pharyngeal flap which  has the most adverse effect [56, 57]. Nonetheless, the pha-  ryngeal flap is the most commonly used method, and a recent  paper by Dentino et al. [58] demonstrated that the superiorly  based pharyngeal flap was highly successful in correcting  VPI after cleft maxillary advancement.    The classification of cleft maxillary hypoplasia is given in  Box 75.10.    The above classification of maxillary hypoplasia needs to  be combined with the age at which the patient presents for  optimal treatment planning. It should be noted that the  regression is calculated only on the basis of reverse dental  overjet. The presence or severity of para-nasal hollowing is  not accounted for in the above classification.    ¢ If surgical treatment (distraction osteogenesis or orthog-  nathic surgery) is performed prior to the skeletal maturity,  there is a high chance of relapse due to continued skeletal  growth. Thus, additional surgery will be required to cor-  rect the residual skeletal deformity. Nonetheless, distrac-    tion osteogenesis is preferred over orthognathic surgery  in the growing patient.   Time constraints and patient’s needs might require you  to modify the ideal treatment plan. Though the overall  facial profile is important, it is equally essential to estab-  lish a functional occlusion with positive overjet and  good intercuspation as they go a long way in preventing  relapse.   Procedures like camouflage orthodontics, face mask pro-  traction, and anterior maxillary distraction produce a  greater change at the dentoalveolar level and fail to sig-  nificantly improve para-nasal hollowing. In case of AMD,  the anterior maxillary osteotomy does not extend suffi-  ciently enough in to the posterior and superior aspect of  the zygomaticomaxillary buttress region.   Orthognathic surgery and total maxillary distraction  (TMD; subtypes, internal maxillary distraction and rigid  external distraction) can both correct para-nasal hollow-  ing when combined with a modified high-level LeFort I  osteotomy.   While operating, the facial profile and occlusion can be  immediately appreciated during orthognathic surgery.  Results can similarly be approximated in total maxillary  distraction (TMD) by activating the distractor to the  desired extent on the operating table. This is possible as  the posterior extent of a conventional LeFort I osteotomy  lies in the region of the more mobile soft palate.   While performing anterior maxillary distraction, the final  facial profile and occlusion cannot be immediately appre-  ciated on the OT table as the posterior extent of the maxil-  lary osteotomy lies anterior to the permanent first molar.  The palatal mucosa in this region is firmly attached to the  underlying bone, and excessive activation of the distractor  can lead to stripping of the mucosa from the underlying  bone.   Masticatory efficiency is not significantly compromised  during AMD, as the device is fairly rigid and the posterior  limit of the osteotomy is anterior to the permanent first  molars. A complete LeFort I osteotomy, like that used in  total maxillary distraction (TMD), reduces masticatory  efficiency on account of increased mobility of the whole  maxilla on the application of masticatory loads.   One needs to take into account that a reverse overjet of  “x mm” requires a net advancement of “x + 2 mm” to  obtain adequate overjet and overbite. Hence, a reverse  overjet of 8 mm requires a net advancement of 10 mm for  adequate correction. If one wants to accommodate for  expected relapse, then one needs to overcorrect by at least  20%. Hence, the actual amount of advancement required  would be 10 + 2, 1.e., 12 mm.   Limits of movements with orthognathic surgery:  Conventional orthognathic surgical advancement of the  maxilla beyond 10 mm increases the risk of relapse on  account of the scar tissue in the soft palate and upper lip    regions. As the mandible is usually unaffected in cleft  maxillary hypoplasia, a setback beyond 8 mm leads to a  poor aesthetic result and is also associated with higher  relapse rates.   A reverse overjet of 16 mm in cleft maxillary hypoplasia  requires a net advancement of 18 mm. The maxilla can be  advanced by 10 mm, and the mandible can be setback by  8 mm to achieve the desired correction. Thus, a reverse over-  jet of 16 mm can be treated by orthognathic surgery with  acceptable stability in the long term. Although it is possible  to treat a reverse overjet greater than 16 mm with orthogna-  thic surgery, it is associated with a higher relapse rate.  When the cleft maxilla is advanced > 10 mm, there is an  increased risk of damage to the palatal vascular pedicle on  account of the inability of the scarred soft palate to stretch  and accommodate the change [59]. Furthermore, there is  also risk of suture site dehiscence in the maxillary labial  vestibule as this region would be closed under tension on  account of the presence of scarred tissue with minimal  elasticity [37, 60].   Distraction osteogenesis (AMD/TMD) can be used for all  spans of maxillary advancement and is preferred for  advancements > 10 mm on account of the stability of  results in the long term [61, 62]. There is also minimal  risk of damage to the palatal vascular pedicle as the  advancement is gradual and a certain degree of histogen-  esis accompanies the distraction osteogenesis.    e« The span of movement (small or large) or mode of  advancement (total maxillary distraction or orthognathic  surgery) is not to be associated with an increased risk for  deterioration of preoperative VPI.   — Determining preoperative speech and VPI status is a  must: perceptual speech assessment, acoustic mea-  surement with nasometer, video nasoendoscopy (or  video fluoroscopy), and lateral cephalometric  analysis.   — If there is no preoperative VPI, then there is minimal  risk for worsening of speech and occurrence of VPI  postoperatively.   — If there is borderline (or greater) VPI preoperatively,  then there is a high risk for worsening of VPI  postoperatively.    The patient has a mixed dentition during this phase. There are  multiple un-erupted dental follicles present that can pose a prob-  lem to certain surgical procedures. Alveolar bone grafting is  preferably performed during this phase as it is associated with  higher success rates [26]. Large oronasal fistulae, if present,  need to be closed prior to secondary alveolar bone grafting.    Less than 6 mm 6 to 10 mm 11 to 16 mm 17 mm & above    If the child presents with a mild regression, one can  choose to wait and watch or proceed with dentofacial ortho-  pedics using a reverse pull headgear to achieve protraction of  the maxilla. If the child presents with moderate regression,  then one must proceed with reverse pull headgear therapy to  achieve some degree of correction.   The usage of reverse facemask therapy requires consider-  able patient co-operation and works by stimulating growth at  the various maxillary suture sites (Fig. 75.2a—c). It is usually  combined with a maxillary expansion appliance that helps  disrupt the circum-maxillary sutural system and increase the  effects of the orthopedic face mask. The general effect pro-  duced is that of a downward and forward movement of the  maxilla, backward rotation of the mandible, and a net  increase in the lower facial height. However, the response  varies widely from individual to individual, and long-term  stability is also questionable [7, 63-66].   The stability and extent of correction with reverse face-  mask therapy reduces with increasing severity of labio-  palatal clefting and absence (or failure) of prior alveolar  bone grafting [63-66]. The degree of ossification of the  zygomaticomaxillary buttress also plays an important role  in the results of facial protraction therapy. Earlier stages  (younger age group) of ossification are associated with a  greater span of movement and skeletal and dental changes.  Later stages of ossification (older age group) are associ-  ated with a smaller span of movement and mainly dento-  alveolar changes [67, 68]. Today, skeletal anchorage is  slowly replacing traditional tooth borne anchorage on  account of better control of degree of rotation of the man-  dible and greater potential for skeletal movements [69,  70]. In patients who are less co-operative, one can con-  sider using a modified technique with inter-maxillary  elastics between a miniplate secured to the zygomatico-  maxillary buttress region posteriorly and another mini-  plate secured to the mandible anteriorly (Bone-anchored  maxillary protraction - BAMP). This technique has pro-  vided promising results which are comparable to tradi-  tional reverse facemask therapy. However, this  modification can be performed only after the eruption of  the mandibular canine to allow for plating in the anterior  mandible [69, 71, 72].   Very rarely will a child present with severe or extreme  regression in this age group. Rigid external distraction (RED)  is the only option available for the correction of such a severe  discrepancy and is mainly used in syndromic patients pre-  senting with moderate to severe obstructive sleep apnea and  in patients with a poor psychological status. RED allows for  high osteotomies as it does not rely on rigid fixation tech-  niques to secure the distractor. This helps avoid injury to  tooth follicles in the growing patient while simultaneously  correcting para-nasal hollowing. On the contrary, internal  total maxillary distraction (ITMD) and anterior maxillary    distraction (AMD) cannot be used as the lower-level osteoto-  mies used in these procedures will damage the un-erupted  dental follicles. The plates of the internal distractor also need  to be secured to the bone with screws, which will also cause  damage to the tooth follicles.   In spite of the above treatments, it is difficult to maintain  results in the long term on account of continued mandibular  growth. Thus, surgery will mostly be required once the  patient reaches skeletal maturity to correct any residual skel-  etal deformity. However, the final amount of maxillary  advancement will be much lesser resulting in increased post-  operative stability of the cleft maxilla.    All permanent teeth (except the third molars) have erupted.  The absence of un-erupted dental follicles makes procedures  like AMD and ITMD (internal total maxillary distraction)  feasible in this age group. Due to deficient arch length, there  may be moderate to severe crowding. Some permanent teeth  may have remained un-erupted, impacted, or erupted ectopi-  cally adding to the complexity of the treatment. If alveolar  bone grafting has not been done prior or has failed, it needs  to be performed during this phase. Large oronasal fistulae, if  present, also need to be closed in preparation for orthogna-  thic surgery.   If the regression is mild to moderate, one can consider cam-  ouflage orthodontics, maxillary protraction therapy, or AMD  in order to create an acceptable occlusion. Alternatively, we  can choose to wait and watch and directly correct the maxil-  lary hypoplasia once growth is complete (Fig. 75.4a, b).   Severe to extreme maxillary regression is preferably  treated with AMD. The available span of most commer-  cially available hyrax screws does not exceed 13 mm.  Thus, there are two options available to the clinician:  repeat the AMD twice in a single stage or in a two-staged  manner (at least | year apart) [50]. The author prefers to  repeat the AMD activation twice, in a single stage. This  requires the fabrication and immediate application of a  fresh appliance, once the first appliance has attained com-  plete activation of the incorporated Hyrax screw. Great  care should be taken to avoid excessive pressure on the  anterior maxilla while fitting the new appliance as the cal-  lus is not fully mature and large forces may easily destroy  it. Alternatively, we can consider total maxillary distrac-  tion UTMD or RED) (Figs. 75.5a—d and 75.6a—f) as long  as the patient does not have moderate to severe preopera-  tive VPI (Also see Fig. 70.17).   In spite of the above treatments, it is difficult to maintain  results in the long term on account of continued mandibular  growth. Thus, surgery will mostly be required once the  patient reaches skeletal maturity to correct any residual skel-    Fig. 75.2 (a—c) Reverse pull headgear therapy in a growing child with application of “reverse-pull headgear”, (c, c1) Post-treatment profile  cleft maxillary hypoplasia. (a, al) Pre-treatment profile and frontal and frontal photographs demosntrating an improvement in the patient’s  photographs, (b, b1) Profile and frontal photographs of patient after profile    ‘ (a, b) Severe reverse overjet at 14 years of age and mild VPI. Anterior maxillary distraction was performed (AMD). Final correction  with orthognathic surgery to be done after 16 years of age    Fig. 75.5 (a—d) Use of internal maxillary distraction in the manage-  ment of CMH. (a) Intra-operative positioning of internal maxillary  ditractors, (b) post-distraction picture prior to the removal of distractor    etal deformity. However, the final amount of maxillary  advancement will be much lesser resulting in increased post-  operative stability of the cleft maxilla.    If prior alveolar bone grafting has failed or has not been per-  formed, a decision should be made as to whether it needs to  be performed or not. Large oronasal fistulae, if present, need  to be closed in preparation for orthognathic surgery.   If the regression is mild to moderate and VPI is absent or  negligible, then either total maxillary distraction, AMD, or  orthognathic surgery can be performed. Orthognathic surgery    devices, (c) Pre-operative lateral cephalogram and (d) Post-operative  lateral cephalogram demonstrating ditractor in-situ    is preferred in this scenario as we can achieve immediate  improvement in facial profile and occlusion (Figs. 75.8a—h,  75.9a-h). If there is moderate to severe VPI preoperatively,  then it is advisable to perform AMD to avoid further deteriora-  tion of the same.   If the regression is severe to extreme and the VPI is  absent or negligible, then either orthognathic surgery  (Fig. 75.10a—f), AMD, or TMD can be performed. AMD  may have to be repeated twice in the same sitting or in a  stage manner as described previously. If optimal esthetics  is the goal, then AMD followed by conventional LeFort I  maxillary advancement is the ideal treatment plan  (Fig. 75.1 1a—g). The only drawback of this procedure is the  prolonged treatment duration as a minimum waiting period    Fig. 75.6 (a-f) Patient treated with rigid external distractor (RED). tographs showing RED in situ. (e, f) Post-operative frontal and profile  (a, b) Pre-operative frontal and profile photographs, demonstating photographs demonstrating good midface fullness and a convex facial  hypoplastic midface and concave profile. (c, d) Frontal and profile pho- _ profile    If AVG not done previously or failed, it has  to be performed prior in a staged manner  or combined with orthognathic surgery    Surgical Management of VPI if  it persists even after 1 year    Fig. 75.7 Treatment plan for age group 17 years and above    of | year is needed between both surgeries. If there is mod-  erate to severe VPI preoperatively, then it is advisable to  perform AMD to avoid further deterioration of the same.  As a means of saving time or if the mandible is truly prog-  nathic, AMD and TMD can be combined with a mandibular  setback (using bilateral sagittal split osteotomy) in a simul-  taneous or staged manner to reduce the span needed to be  distracted [73].    Chronic Maxillary Sinusitis Most CLP patients suffer from  chronic maxillary sinusitis on account of the presence of    Larger fistulae need to be corrected prior and  small fistuale at the same time as orthognathic  surgery    Severe [11 to 16 mm] and  Extreme [17 m and above]    nasal obstructions and residual oronasal fistulae. It is the  author’s opinion that such patients need to be referred to an  ENT specialist at least 3 months prior as active sinusitis  affects the quality of the bone in the maxilla.   Clinical diagnosis, pre-anesthetic assessment  (blood investigations, chest x-ray, ECG, additional  investigations for any significant medical history),  facial photographs, cephalometric analysis (lateral  cephalogram and postero-anterior cephalogram), artic-  ulated study models with bite registration and facebow  transfer, dental model analysis, orthopantomogram,  perceptual speech assessment, video nasoendoscopy  (or video fluoroscopy) for velopharyngeal insuffi-  ciency, psychological screening, and patient education  regarding realistic expectations   3D computed tomography scans, stereolithographic  model, sleep studies, and 3D virtual surgical planning    Fig. 75.8 (a—-h) Mild reverse overjet and no preoperative VPI. The  patient was treated with single jaw orthognathic surgery (maxillary  advancement). (a, b) Pre and post-operative frontal photographs. (c, d)    A single dose of 8 mg dexamethasone (half-life of 36-54 h)  is given preoperatively to help reduce postsurgical airway  and maxillofacial edema. It also has a synergistic analgesic  effect when combined with postoperative analgesics. As a  only a single dose is given, it is associated with minimum  side effects [74, 75]. A single dose of | gm tranexamic acid  is given | h preoperatively as it helps reduce intraoperative  blood loss [76].    Nasal intubation is preferred followed by submental intuba-  tion. In case a pharyngeal flap or nasal obstruction (enlarged  inferior turbinates or deviated nasal septum) is present, it is  advisable to perform fiber-optic assisted awake intubation.    Pre and post operative profile photographs (left side). (e, f) Pre and  post-operative profile photographs (right side). (g, h) Pre and post-oper-  ative lateral cephalograms    Alternatively, it may be necessary to pass a more rigid tube  or catheter initially after which the endotracheal tube is  passed over it.   The author always prefers to use a flexometallic naso-  endotracheal tube as the tube is able to maintain its integrity  even if damaged during the LeFort I osteotomy on account of  the additional strength imparted by the metal coils.    The author commonly uses hypotensive anesthesia during  orthognathic surgery as it provides a clean hemostatic field,  reduces blood loss, and shortens hospital stay. There is an  association between hypotensive anesthesia, forces gener-  ated during pterygomaxillary dysjunction, and optic nerve  damage. Risk for optic nerve damage increases when hypo-  tensive anesthesia is used in head and neck surgery which is    Fig. 75.9 (ah) - Moderate reverse overjet and mild preoperative VPI.  The patient was treated with orthognathic surgery alone (maxillary  advancement and advancement genioplasty). (a, b) Pre and post-opera-    prolonged (>6 h) and large amount of blood loss (> 1| 1) has  taken place [77-82].   A larger amount of force is needed for pterygomaxillary  dysjunction in CLP patients on account of the thicker ptery-  gomaxillary junction. The stray forces, generated as a result  of the dysjunction, can dissipate toward the orbital cavity  and optic foramen with a magnitude potent enough to cause  damage to the optic nerve. This is possible due to the orbital  extensions of the palatine and sphenoid bones [7, 83, 84].  Thus, the author prefers to maintain hypotensive anesthesia  during the entire orthognathic surgery except during ptery-  gomaxillary dysjunction.    In cases of unilateral CLP, a routine incision in the height of  the maxillary vestibule is used, and care should be taken that  it extends only to the mesial surface of the first maxillary    tive frontal photographs. (c, d) Pre and post operative profile photo-  graphs (left side) (e, f) Pre and post-operative profile photographs (right  side). (g, h) Pre and post-operative lateral cephalograms   In cases of bilateral CLP, the incision is modified such  that it extends from the lateral incisor to mesial surface of the  first molar on both sides. A vertical stab incision is made in  the midline to allow for placement of the nasal septal osteo-  tome. This is to preserve blood supply to the pre-maxillary  segment as most of its blood supply comes from the upper lip  (2, 7, 28, 30].   Frequent surgery in the cleft maxilla leads to creation of scar  tissue in the buccal, palatal, and upper lip regions. This scar  tissue has compromised vascularity and healing ability.  Therefore, it is essential to maintain an adequate soft tissue  pedicle. There have also been suggestions to use modified ver-  tical incisions instead of circumvestibular incisions, but it  increases the difficulty of the procedure manyfold due to poor  access and visualization [2, 3, 86]. Careful and gentle retraction  of tissues (especially the pedicles) is essential throughout the  procedure and especially during the down-fracture process.    Fig. 75.10 (a—f) Severe reverse overjet and mild preoperative VPI. The patient was treated with bi-jaw orthognathic surgery. (a, b) Pre and post  operative frontal photographs. (c, d) Pre and post operative profile photographs. (e, f) Pre and post operative lateral cephalograms    The nasal mucosa is routinely elevated from the walls and  floor of the nasal cavity prior to starting the LeFort I osteot-  omy. In the cleft maxilla, there is no intervening bone  between the oral and nasal cavity in the region of the cleft;  instead, the nasal mucosa is fused to the palatal mucosa due  to the previously performed palatoplasty. This tissue should  be sharply dissected close to the nasal floor, and care should  be taken to avoid perforating the palatal mucosa. This step  also aids in the down-fracture and mobilization of the  maxilla.   The cleft maxilla usually exhibits para-nasal hollowing.  Hence, the routine LeFort I osteotomy may not suffice for  complete correction of cleft maxillary hypoplasia. Instead a  high LeFort I osteotomy is used which has the added advan-  tage of correcting the para-nasal hollowing as well [7, 30,  86]. Care should be taken to avoid damage to the tooth roots    and the infra-orbital nerve as it exits from the infra-orbital  foramen (Fig. 75.12). One should keep in mind that the  descending palatine artery is closer to the lateral pyriform  rim while performing the lateral nasal wall osteotomy.   To completely mobilize the maxilla during a LeFort I  osteotomy, it is necessary to perform a pterygomaxillary  dysjunction which separates the maxilla from the ptery-  goid plates. The maneuver is essentially blind and involves  orienting a pterygoid chisel (curved osteotome) in a down-  ward, medial, and anterior direction such that it engages  the lower part of the pterygomaxillary fissure while main-  taining a safe distance from the internal maxillary artery  [87-89].   Studies have revealed that the medial pterygoid plate is  shorter and the pterygomaxillary junction is thicker in cleft  patients as the region around the hamular notch is fre-    Fig. 75.11 (a—g) Extreme reverse overjet and mild preoperative VPI.  Ist stage corrected by anterior maxillary distraction (AMD). Note the  persistent para-nasal hollowing that is only partially corrected by AMD.  2nd stage completed by bi-jaw orthognathic surgery (OGS) with  improvement in para-nasal hollowing. (a) Pre-operative profile photo-    quently manipulated during palatoplasty. The shorter  medial pterygoid plate, by virtue of its smaller dimensions,  may be more prone to fracture which increases the risk for  vascular complications [87, 88]. Furthermore, the thicker  pterygomaxillary junction requires a larger magnitude of  force to achieve adequate separation. The usage of greater  force leads to less control over this blind manoeuvre, thus  increasing the risk for vascular complications (internal  maxillary artery damage, carotid cavernous sinus) and neu-  rologic (optic nerve damage) and skull base fractures  (sphenoid fractures) [84].    graph. (b) Profile after stage 1 correction wthe AMD. (c) Profile after  stage 2 correction with orthognathic surgery. (d) Pre-operative lateral  cephalogram. (e) Lateral cephalogram after stage 1 - AMD. (f) Post-  consolidation lateral cephalogram. (g) Lateral cephalogram after stage  2 -orthognathic surgery    There have been many modifications suggested to the  original technique with an intention to reduce complications  [87, 88, 90-95]. However, their use has never been docu-  mented widely in CLP cases. One may also attempt to use a  piezo-surgical instrument or sequentially increase the size of  the osteotomes to help reduce the force required for final  pterygomaxillary separation [96, 97]. Another important  consideration would be the preference of a third molar verti-  cal osteotomy cut instead of a pterygomaxillary disjunction.  This manoeuvre is anatomically less hazardous, allows  greater mobility of the segments, allows a larger vascular    pedicle to be maintained and permits the use of interposi-  tional bone graft in the osteotomised area, after the advance-  ment in order to prevent relapse.   Once pterygomaxillary dysjunction has been per-  formed, the maxilla is down-fractured using leverage or  specialized instruments like the Smith’s spreader. If the    Fig. 75.12 Modified high LeFort I osteotomy (blue) cut to help correct  para-nasal hollowing. Avoid damage to the infra-orbital nerve (yellow)  and roots of teeth (white) while making the osteotomy. The pyrifiorm  rim is marked in orange    nasal mucosa has not been dissected from the palatal  mucosa previously, then it has to be done at this point [2,  7, 30]. After the down-fracture, it is important to suture the  divided edges of the nasal mucosa to regain continuity of  nasal lining. In the author’s opinion, the edges of the  divided nasal mucosa are a common source of bleeding  postoperatively if left un-sutured (Fig. 75.13a, b). The  presence of nasal obstructions like enlarged inferior turbi-  nates can be corrected at this time.   After the down-fracture, the process of mobilizing the  maxilla is done in a gradual progressive manner as the scarred  tissues are less compliant. Specialized instruments like the  Tessier’s mobilizer can be used. If a pharyngeal flap is present  and is impeding maxillary advancement, it may need to be  incised. The maxilla is finally advanced to its desired position  and should be seated in a passive manner. Signs of resistance  at this point may indicate that the maxilla has not been ade-  quately mobilized, and the previous steps need to be revisited.  If resistance to the desired maxillary position persists, then  one must consider to switch to maxillary distraction or set-  back the mandible to avoid postoperative relapse. In situations  where an alveolar bone grafting procedure has not been per-  formed, or where the take of the grafting is sub-optimal, the  cleft maxilla may present as a two-piece (unilateral cleft) or a  three-piece (bilateral) maxilla. This may necessitate the use of  transverse maxillary plating (Fig. 75.14a, b), for stabilization  of the segmented bone.   There may also be need for segmental osteotomies as it is  difficult to completely co-ordinate both arches with presurgi-  cal orthodontics on account of the variable anatomy of the  cleft maxilla. The cleft alveolar gap can be opened or closed    Fig. 75.13 (a) Torn nasal floor mucosa after down-fracture of maxilla. The endotracheal tube is visible. (b) The torn edges should be sutured back    Fig. 75.14 Transverse plate across maxilla for stability during LeFort I osteotomy in a cleft. (a) Unilateral cleft of maxilla (b) Bilateral cleft of    to facilitate alveolar bone grafting or close alveolar fistulas.  It can widen the maxillary arch within acceptable limits,  allow differential movement of greater and lesser segments,  align the occlusal plane, and maximize intercuspation to  improve postoperative stability [98].   The presence of a persistent oronasal fistula and alveolar  cleft defect requires careful soft tissue closure and bone  grafting. One can also augment the deficient area along the  lateral piriform rim on the cleft side to improve the contour  of the alar base. The maxilla can fracture at the cleft alveolus  site into two segments during the down-fracture and mobili-  zation, even when the alveolar cleft site has been previously  grafted. A preoperatively fabricated surgical palatal stent  helps stabilize the maxilla in this situation.   Rigid fixation with mini plates and screws is preferred to  stabilize the maxilla in its final position with a preference for  the lateral pyriform rim and zygomaticomaxillary buttress  regions as the bone here is thicker [83, 99]. One should pay  attention while suturing and prevent entrapment of soft tissues  into the osteotomy sites. The soft tissue of the upper lip may be    75.8.6 Additional Steps Performed on a Case-  to-Case Basis  75.8.6.1 Deciding the Level of Midface  Advancement (Fig. 75.15a-f)  In most of the cases, a traditional LeFort I (Fig. 75.15a) oste-  otomy is advocated. However, in some rare instances, it may  need a LeFort II (Fig. 75.15b) or LeFort II (Fig. 75.15c)  osteotomy depending on the severity and the extent of the  involvement. As the CMH involves the pyriform, the para-  nasal, and the zygomatic areas, though not symmetrical, the  LeFort I osteotomy design in such situations may need modi-  fication to involve the para-nasal (Fig. 75.15d) and/or zygo-  matic (Fig. 75.15e) areas unilaterally (Fig. 75.15f) or  bilaterally as the case may be.    Fig. 75.15 Levels of midface advancement (a) LeFort I, (b) LeFort II, conventional LeFort I on the unaffected side and para-nasal extension  (c) LeFort III osteotomies. Modifications of LeFort I osteotomy (d), on the affected side  para-nasal extension, (e) para-nasal and zygomatic extensions, and (f)   Studies by Bell et al. established that the descending palatine  artery did not contribute significantly to the re-vascularization  of the maxilla after a total maxillary osteotomy in routine  cases [100, 101]. However, the greater palatine arterial net-  work in CLP patients may become narrow and develop vas-  cular anomalies because of the presence of scar tissue created  by the palatoplasty procedure [7, 60, 83]. Considering the  unique scenario of the cleft maxilla, it is advisable that  efforts should be made to preserve the descending palatine  artery and secure it as an additional source blood supply for  the osteotomized maxilla [7, 102]. Techniques to identify  and preserve the descending palatine artery have been docu-  mented in the literature [103-108]. However, the above tech-  nique needs to be tailored to the cleft maxillary anatomy as it  is highly variable. Studies have established that the distance  between the lateral pyriform aperture and the descending  palatine artery is on an average 3-4 mm lesser in CLP  patients. Similarly, the posterior and lateral distances to the  descending palatine artery were greater on in CLP patients  on account of the thickened pterygomaxillary junction [7,  83, 84]. The perpendicular process of the palatine bone sur-  rounding the descending palatine artery is also of the dense  cortical type adding to the difficulty of isolating the vessel  [99]. The author reserves this step only when the patient has  undergone a large number of revision surgeries in the  palate.   The cleft maxilla is deficient in all three dimensions, and  hence its correction requires complex large movements.  Cortico-cancellous bone grafts can be placed across the gap  created in the region of the lateral osteotomy [2, 3, 7, 86,  109]. The ideal source of autogenous bone grafting is the  anterior iliac crest [110]. As an alternative, one can also use  autogenous genial grafts, allogenic grafts, or synthetic  hydroxyapatite bone blocks [111-114]. The author prefers to  graft the osteotomy site only when down-grafting the max-  illa or advancing the maxilla more than 10 mm.    According to Stork et al. and Chua et al., there was no major  difference between clinical morbidity between distraction  osteogenesis and orthognathic surgery and between grafted  and non-grafted patients, the source of graft being the ante-  rior iliac crest [115-117].   Patients undergoing distraction osteogenesis experi-  enced greater levels of stress in the short term. Over time,    the distraction group had a higher satisfaction with life  [118-120]. This may be because of the better stability of  the distraction osteogenesis in the long term as well as  the self-perceived contribution of the patients to the suc-  cess of their treatment. There is also an aspect of superior  soft tissue response to distraction as compared to orthog-  nathic surgery which may improve the final aesthetic  result (refer Chap. 87 to read more about Distraction  Osteogenesis) [121].   Nonetheless, psychological support from family and  friends is recommended for patients undergoing either dis-  traction or orthognathic surgery so as to achieve a better life  satisfaction in the long term.    The postoperative stability after orthognathic surgery in  cleft patients is lower than non-cleft patients [2, 3, 7, 86].  Maximum relapse in cleft orthognathic surgery occurs in the  first 6 months, and the situation stabilizes 2 years postopera-  tively [122].    The presence of scarred tissue in the palate and the lip pre-  vents the maxilla from being adequately mobilized. Though  the maxilla might be secured into its desired position with  the help of rigid fixation and bone grafting, the excess  stress placed on the maxilla due to the scarred soft tissue  envelope leads to relapse in both the sagittal and vertical  dimensions [2, 3, 7, 86, 123]. The severity of labio-palatal  clefting and history of multiple revision surgeries increase  the risk for relapse.    The amount of surgical movement is the most important fac-  tor that determines the degree of relapse in cleft and non-  cleft cases. Thus, most surgeons tend to overcorrect by an  additional 20% to account for the possible relapse [2, 3, 7,  86, 124].   However, a recent study by Watts et al. [125] suggested  that amount of linear advancement was not a major cause for  skeletal and dental relapse rate in cleft orthognathic. Studies  by Bhatia et al. [59] and Hoffman et al. [126] suggested the  same. Nonetheless, the general trend is to perform bi-jaw  orthognathic surgery or distract the maxilla if more than  10 mm advancement is needed.    Lack of alveolar bone grafting increases the difficulty of per-  forming cleft orthognathic surgery. However, though alveo-  lar bone grafting contributes to transverse stability of the  maxillary arch and improve outcomes in orthodontia, it does  not improve stability of sagittal, vertical, or rotational move-  ments [122, 124].    Inadequate separation at the pterygomaxillary junction due  to its thicker form in CLP patients, the presence of a pharyn-  geal flap, a shallow overbite, and the absence of multiple  teeth leading to poor intercuspation may contribute to relapse  as well [2, 3, 7, 86, 124]. Segmentation of the maxilla as  compared to one-piece maxilla was not associated with  greater relapse rates in CLP patients and instead could cor-  rect orthodontic and occlusal problems that were distinctive  to the cleft maxilla. Nonetheless, no attempt should be made  to significantly widen the cleft maxilla as using a segmental  osteotomy is a highly unstable procedure [98, 127, 128].   In the author’s opinion, poor-quality bone in the cleft  maxilla makes rigid fixation difficult and increases the risk  for relapse [2, 3, 7]. Thus, it is advisable to always secure  plates in the region of thick cortical bone, i.e., the zygomati-  comaxillary buttress region posteriorly and the lateral pyri-  form aperture anteriorly (Fig. 75.16a—c). Bony fenestrations  can be encountered in cases with prior AMD during maxil-  lary orthognathic surgery; extra care must be taken during  plating the same (Fig. 75.17).    Owing to the large advancements commonly performed  in cleft orthognathic surgery, the gap between the osteoto-  mized segments is large. When the contact area between the  bony shelves is small, there may be instability or fibrous  union between segments which increases the risk for relapse.  By grating these gaps, there is increased bony contact which  helps in optimal healing. Rarely, the space posterior to the  maxillary tuberosity after advancement of the maxilla is also  grafted to help prevent relapse [46]. Owing to the hostile  environment of the cleft maxilla, it is general consensus that  autogenous bone grafts provide the best results in terms of  take up of the graft and significantly lower complication  rates. It is interesting to note that a recent study by Stork  et al. [115] suggested that grafting was not a major factor in  preventing postoperative skeletal relapse in cleft and non-  cleft patients contrary to the currently accepted methodol-  ogy. A study by Hoffman et al. [129] in non-cleft patients  suggested the same. The author’s opinion is in line with both  the above authors and grafts the osteotomy site only when  advancing the maxilla more than 10 mm or down-grafting  the maxilla.    As previously mentioned, surgery performed before skeletal  maturity is associated with a higher relapse rate in both hori-  zontal and vertical dimensions due to continued growth. This  is applicable irrespective of the type of surgery being per-  formed: orthognathic surgery or distraction osteogenesis [21,  23, 24]. Secondary surgery for the correction of residual  growth deformities is required after growth is complete. It is    Fig. 75.16 (a—c) Poor-quality bone seen in the anterolateral and pos-  terolateral walls of the maxilla. Always plate along the lateral pyriform  rim and zygomamaxillary buttress (dotted) region which are known to    have good-quality bone. Part of the miniplate obscured by the retractor  and tissues has been traced for better understanding of the plate posi-  tion. Blue line denotes line of osteotomy on the dental side    Fig. 75.17 Large bony fenestration in anterolateral wall of the maxilla  at the time of orthognathic surgery. It is commonly found where prior  anterior maxillary distraction was done. The presence of such a large  fenestration can make plating difficult    important to note that distraction osteogenesis was more com-  monly preferred in the growing patient [2, 3, 7, 22, 130, 131].    A review by Kloukos et al. [120] established that results  obtained with distraction osteogenesis were more stable as  compared to conventional orthognathic surgery 5 years post-  operatively. A review by Saltaji et al. [132, 133] reported  average horizontal relapse rates of 10 % in distraction cases  and 25-30 % in orthognathic cases for cleft patients. Vertical  relapse rates in cleft orthognathic patients were high with an  average rate of 40-50 %. Similar results have been docu-  mented in other studies and reviews with up to 5-year follow-  ups [134-140]. The rate for re-operation in cleft orthognathic  surgery was approximately 12.2% [140]. Internal distractors  were also found to be more stable than external distractors.  This can be attributed to the rigidity provided by the internal  distractor during the consolidation phase. The use of rigid  fixation with miniplates was attributed with the least amount  of relapse in cleft orthognathic surgery [2, 3, 7, 132].   Based on the above evidence, distraction osteogenesis has  become the mainstay for the management of severe to  extreme cleft maxillary hypoplasia (reverse overjet greater  than 11 mm) as the slow distraction of bone and the  accompanying histogenic abilities help reduce skeletal  relapse. Orthognathic surgery is preferred for mild to moder-  ate cleft maxillary hypoplasia (reverse overjet lesser than  11 mm).    Commonly used methods to prevent or control relapse are  as follows: overcorrection of the final surgical result by  20%, prolonged intermaxillary fixation during the postop-  erative phase, using face masks with reverse traction of the  maxilla, interpositioning bone grafts between the gaps cre-  ated by maxillary advancement, and performing bi-jaw sur-  gery or distraction when advancements greater than 10 mm  are required [114]. A study by Tabrizi et al. [141] estab-  lished that the use of rigid fixation after the consolidation  phase of cleft maxillary distraction did not increase stability  of results. In anterior maxillary distraction, it is essential to  lock the appliance with wire or acrylic plug during the con-  solidation phase to prevent backward rotation of the hyrax  screw.    A study by Metalwala et al. [142] established that there is  increased risk for infection and prolonged hospital stay in  patients with craniofacial anomalies undergoing orthogna-  thic surgery. The incidence of complications in non-cleft  patients has been reported at 6.4% as compared to 25.2% in  cleft patients [83].   Studies by Yamaguchi et al. [140] and Moran et al. [143]  revealed that an average of 15-30 % of patients present  with perioperative complications. The most common com-  plications were closure failure of pre-existing palatal fis-  tula, velopharyngeal impairment, temporary paresthesia of  the infra-orbital nerve, and surgical site infection. A review  by Santos et al. [144] established that cleft maxilla patients  present with the highest incidence of cranial nerve damage  on account of the anatomically higher modified LeFort I  osteotomy cut and excessive forces needed at the time of  pterygomaxillary dysjunction. Rare and severe complica-  tions like arteriovenous fistula, maxillary aneurysm, cav-  ernous sinus thrombosis, skull base fractures, and maxillary  necrosis blindness are more common among patients with  craniofacial anomalies but have an incidence of lesser than  0.5% [140, 143, 145]. It has been suggested by Eduardo  et al. [146] that the use of piezo-electric surgical instru-  ments in orthognathic surgery is associated with a lower  complication rate.   With the author’s experience (PM) of approximately 900  cleft orthognathic cases while using the traditional dysjunc-  tion technique, there has been no major vascular complication  or skull base fractures. However, two patients experienced  transient blindness with partial recovery of vision in the long  term [79].    Skeletal surgery is a critical component of surgical management  of CLP. On account of the unique anatomy of the cleft maxilla  that has been subjected to previous lip & palate interventions,  the conventional LeFort I osteotomy technique and orthogna-  thic surgical principles need to be adapted accordingly. The ulti-  mate goal of treatment should be to achieve intelligible speech  and an acceptable appearance with good balance of facial skel-  eton, soft tissues, and occlusion. Distraction osteogenesis is a  useful technique in the management of severe maxillary defi-  ciency, but does not replace conventional orthognathic surgery.  Maxillofacial surgeons who treat these deformities should be  part of a craniofacial team to provide interdisciplinary care for  the patient. The aim of the team should be to help the child to  develop into a confident young adult.    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Piezoelectric versus conventional techniques for orthog-  nathic surgery: Systematic review and meta-analysis. J Cranio  Maxillofacial Surg. 2017;45(10): 1607-13.    Open Access This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.  org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropri-  ate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.   The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in  a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.   Rhinoplasties in cleft lip and palate (CLP) patients are con-  sidered one of the most difficult and challenging surgeries to  carry out. The reasons understood for this are twofold: the  principal reason being the simultaneous involvement of all  the layers of the nose, including the skin, cartilage, skeleton  and vestibular lining, and the other the significant scarring  that accompanies multiple previous surgical interventions.  The deformity has a major impact on nasal aesthetics as well  as function and can range from being absolutely inconspicu-  ous to catastrophic.   The literature is flooded with numerous techniques for  ultimate correction of unilateral and bilateral cleft lip-nasal  deformities. More recently, most cleft surgeons have started  opting for primary rhinoplasties at the time of lip repair with  or without presurgical orthopaedics. These early interven-  tions have definitely improved the nasal deformity and the  overall nasal symmetry; however, definitive rhinoplasty may  still be required at a later date as the child grows. Despite all  the recent developments in cleft surgery, an optimal surgical  modality that addresses the issues of desired nasal form cou-  pled with long-term stability for correction of cleft lip-nasal  deformity still fails to exist.    Electronic Supplementary Material The online version of this chap-  ter (https://doi.org/10.1007/978-98 1-15-1346-6_76) contains supple-  mentary material, which is available to authorized users.    S. Richardson   Richardson’s Dental and Craniofacial Hospital,  Chunkan Kadai, Nagercoil, Tamil Nadu, India    R. V. S. Khandeparker  Department of Oral and Maxillofacial Surgery, Goa Dental College  and Hospital, Bambolim, Goa, India    © The Association of Oral and Maxillofacial Surgeons of India 2021    A clear understanding of the associated complex anatomical  and pathological abnormalities is paramount to obtaining  desired nasal form and function [1].    The hallmark of unilateral cleft nasal deformity is a three-  dimensional asymmetry of the nasal tip and the alar base  (Fig. 76.la—c). The characteristic features include:    1. Asymmetric nasal tip: This is principally due to a  shorter medial crus and longer lateral crus of the lower  lateral cartilage (LLC) on the cleft side as compared to  the non-cleft side. This contributes to a poorly defined  nasal tip with less projection [2]. Furthermore, the angle  between the medial and lateral crura on the cleft side is  increased.   2. Alar dome is flat and wider on the cleft side due to  posterolateral displacement of the alar dome [2].   3. Deviation of the columellar base to the non-cleft side:  The unilateral cleft results in a discontinuous insertion  of the orbicularis oris muscle into the columellar base on  the non-cleft side rather than a horizontal insertion and  continuous decussation as seen in the normal lip. The  contraction of the orbicularis oris muscle results in an  unopposed pull of the columella, caudal septum and pre-  maxilla to the non-cleft side [3].   4. Alar base on the cleft side is directed laterally, poste-  riorly and inferiorly: Two factors contribute to this:  one being the insertion of the orbicularis oris into the  alar base and the other the deficient maxillary skeletal  framework at the alar base [3].   6. Wide and horizontally directed nostril on the cleft  side: This is brought about by a combination of vector of    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1-15-1346-6_76    Fig. 76.1 (a—c) Photographs depicting the pathologic anatomy as  observed in unilateral cleft nasal deformity. (a) Frontal view showing  the deviation of the nasal root towards the non-cleft side with asym-  metrical appearing nasal tip. (b) Basal view depicting the deviation of  the base of the columella to the non-cleft side. Also, observe the wide    orbicularis oris muscle pull and asymmetric LLC on the  cleft side [4, 5].   7. Deviation of the caudal septum to the non-cleft side:  The unopposed pull of the orbicularis oris muscle due to  its improper insertion into the columellar base results in  deviation of the caudal septum to the non-cleft side [3].  This force affects only the caudal septum and results in  deflection of the cartilaginous and bony septum into the  cleft side posteriorly. This alone or in association with  hypertrophied nasal turbinates significantly narrows the  opening of the nasal airway and contributes to nasal air-  way obstruction [6].   8. Compromised external nasal valve: This is the conse-  quence of two related factors: introversion of the nasal  ala and webbing of the nasal vestibule. Due to the posi-  tion of the columella and alar base on the cleft side, the  LLC is subjected to distortional forces that causes it to  rotate posteroinferiorly and brings about introversion of  the cleft side nasal ala [7]. This leads to hooding and  thickening of the ala and together with surgical scarring  forms an oblique fold and contributes to webbing of the  nasal vestibule. This tissue bulk has an influence on the  nasal airflow and significantly alters the relationship of  upper lateral cartilages (ULCs) and LLCs.   9. Weakened upper lateral cartilages (ULC) and abnor-  mal relationship to LLCs: On the cleft side, the ULC  displays side-to-side relationship rather than the typical    and horizontally directed nostril on the cleft side. Furthermore, the alar  base on the cleft side is directed laterally, posteriorly and inferiorly. (c)  Pictorial depiction of deviation of the caudal nasal septum (blue)  towards the non-cleft side    overlap type of relationship seen on the non-cleft side.  The ULC on the cleft side is also weakened by inade-  quate skeletal support [8]. The consequence of both  these factors is reduced support and collapse of the ULC  with deep inspiration.   10. Compromised internal nasal valve on the cleft side:  This is primarily because of septal bowing into the cleft  side at the internal nasal valve together with weakened  support of the ULC at the cleft side which causes the  cartilage to collapse with respiration.    The bilateral cleft lip nasal deformity is grossly symmetrical  and shares similar clinical characteristics as observed in uni-  lateral cleft deformity [9, 10] (Fig. 76.2a-c). The clinical  characteristics include:    1. Under-projected and bifid nasal tip: The lateral crus  of the LLC is long, and the medial crus is short which  leads to under-projection of the nasal tip. The medial  crura are typically splayed, producing a poorly defined,  bifid tip [11]. The nose is wide and depressed.   2. Blunting of the alar dome with a more obtuse angle  due to posterolateral displacement of the alar domes  [11].    Fig. 76.2 (a—c) Photographs depicting the pathologic anatomy as  observed in bilateral cleft nasal deformity. (a) Frontal view demonstrat-  ing a more or less symmetrical deformity with bifid nasal tip and blunt-  ing of the alar dome. (b) Basal view depicting symmetrical position of    3. Short columella with a wider base: The columella is  short or nearly absent as a consequence of decreased  soft tissue and skin between the nasal tip and the upper  lip [12].   4. Alar bases are displaced laterally, posteriorly and  inferiorly. This brings about flaring of the alar bases and  widening of the nostrils.   6. Nostrils are wide and horizontally directed with  margins buckling inwards.   7. Classical midline positioning of the septum. The nasal  septum is classically midline; however, in case of a  slight discrepancy, the septum deviates to the less  affected side [13, 14].   8. The external nasal valve is compromised by introver-  sion of the LLCs and webbing of the nasal vestibules  bilaterally.   9. The ULCs are weakened and display abnormal rela-  tionship to LLCs similar to that seen in the unilateral  cleft nasal deformity.   10. The internal nasal valve is compromised by weak-  ened support of the ULC: It is important to note that  midline positioning of the nasal septum in bilateral cleft  nasal deformity results in compromise of the internal  nasal valve to a lesser significant degree as compared to  the unilateral cleft nasal deformity.    the caudal nasal septum, short columella and bilateral displacement of  the alar bases laterally, posteriorly and inferiorly with wide and hori-  zontally directed nostrils bilaterally. (¢) Pictorial depiction of the clas-  sical midline position of the caudal nasal septum    The timing of cleft lip nasal repairs can be divided into pri-  mary, intermediate and secondary or definitive repairs.    Initially, most surgeons were sceptical with early nasal inter-  ventions at the time of cleft lip repair following demonstrations  of impairment of nasal and midfacial growth in experimental  studies that resulted after large submucosal resections of the  nasal septum. However, studies by McComb and Coghlan [7]  have dispelled this philosophy and demonstrated that early  interventions seldom interfere with growth provided the lower  lateral cartilage is only repositioned and not resected. Primary  rhinoplasties are now increasingly accepted, and their positive  effects on secondary rhinoplasties are well documented.   Primary cleft rhinoplasty is typically carried out at 3  months of age at the time of primary cheiloplasty [15]. An  early intervention improves the existing cleft nasal deformity  by achieving better symmetry, allowing the nose to grow ina  symmetric fashion and potentially improving long-term  appearance and the final outcome.   The definite goals of the procedure are highlighted in Box  76.1.   ¢ To bring about approximation of the nasal floor to  establish a muscle and soft tissue sill across the  nasal base   ¢ Repositioning of the alar base and correction of the  webbed lateral alar mucosa by plicating skin and  mucosa [16]    The addition of presurgical naso-alveolar moulding  device is advocated by some authors in conjunction with pri-  mary surgery. The technique delivers continuous low-level  pressure on the alveolar segments and is highly successful in  shaping the nasal cartilage within the initial 6 weeks due to  high levels of circulating maternal oestrogen that makes the  cartilage increasingly elastic [17].   The technique helps in bringing the alveolar segments  closer thereby narrowing the cleft gap, improving the alar  base symmetry, expanding the soft tissue envelope and elon-  gating the columella [18, 19].    Intermediate rhinoplasty is reserved for procedures that are  carried out prior to completion of nasal growth, in the time  interval spanning between definitive lip repair and secondary  rhinoplasty. The procedures are planned on the lines of con-  servation with the singular aim to achieve symmetry during  continued nasal growth, ultimately creating a definitive plat-  form for a more successful definitive repair.   The primary goal of surgery is to correct the abnormal  position of the LLC on the cleft side so that there is no exac-  erbation of the deformity following nasal growth in future. It  is imperative to perform a septorhinoplasty or cartilage graft-  ing procedures in the post-adolescence age so that the nasal  growth proceeds unimpeded [11].   Intermediate rhinoplasty can be carried out at two distinct  time intervals [20]. One corresponds to 4—6 years of age, and  this age group coincides with the timing of lip revision if  required and also helps in achieving a better nasal symmetry.  Also, this is the time when the peer pressure starts to mount    necessitating the need for intermediate rhinoplasty in this  age group. Furthermore, any lateral vestibular webbing can  be dealt with preventing the obstruction of the external nasal  valve.   The other instance when an intermediate rhinoplasty can  be carried out is after completion of orthodontic alignment  and secondary alveolar bone grafting (8-12 years). This  helps in creating a solid skeletal platform to affect a long-  lasting correction of severe nasal deformities.    Secondary or definitive rhinoplasty is performed once the  maxillary and nasal growth ceases, which corresponds to  14-16 years of age in females and 16-18 years of age in  males [21]. The procedure has to be definitive and provides  an opportunity to introduce aggressive surgical interventions  like septorhinoplasty, nasal osteotomies and cartilage graft-  ing manoeuvres without fear of jeopardising the maxillary or  nasal growth.    e Create a lasting symmetry and definition of the  nasal base and tip.   e Correct short columellar skin if present, and aug-  ment the nasal dorsum in cases of bilateral cleft  nasal deformities [1].    Most CLP patients present with maxillary hypoplasia and  therefore require maxillary advancement surgery in the form  of either LeFort I osteotomy, total maxillary distraction or  anterior maxillary distraction. The maxillary projection can  be improved with these procedures without affecting the  nasal dorsum adversely [22]. These procedures also allow  for forward movement of LLC and improvement of the tip  projection. In scenarios such as this, definitive rhinoplasty is  often carried out after addressing the skeletal discrepancies.    Prior to carrying out a rhinoplasty surgery, it is prudent to  carry out a thorough evaluation of the nose in a meticulous  manner. This when backed up with sound knowledge of  nasal anatomy can bring about aesthetically pleasing results  in cleft rhinoplasty.    It is imperative to address any patient concerns as related to  symmetry of the lip and nose, nasal airway, etc. prior to car-  rying out a rhinoplasty surgery. Any previous nasal surgeries  have to be documented accurately. The effects of such sur-  geries on the postoperative outcomes have to be explained to  the patient beforehand.    A thorough physical examination involves examining both  the external appearance and the internal nasal structures.   External examination of the nose must be carried out in  accordance with its position on the facial skeleton.  Measurements as traced on preoperative photographs can  provide a guide in the surgical planning (Fig. 76.3a—d).   Internal nasal examination proceeds in a systematic and  repeatable manner and is performed using a nasal speculum  to evaluate for the nasal function.   When performing the physical examination of the nose,  the clinical characteristics of unilateral and bilateral cleft  nasal deformities as previously described are looked up for  in a systematic manner. Gunter diagrams can be a valuable  aid for the purpose of preoperative planning [21].   Appropriate documentation of the deformity is made possi-  ble by taking preoperative photographs in all views, viz.  frontal, basal, lateral and oblique views (Fig. 76.4a—f). These  photographs serve diagnostic purpose as well as help in pro-  tecting the surgeon in cases of medico-legal implications.  The photographs also help in explaining the goals of surgery    adequately to the patient. Furthermore, the photographs can  serve as a visual guide to the surgeon intraoperatively, help-  ing in implementing the planned surgical goals precisely.   This method requires a set of devices, viz. an optical system,  digital communication network and a computer with a calcu-  lation program which helps in determining the shape of the  three-dimensional object by transforming the image from  analogue to digital form (Fig. 76.5a). The technique is reli-  able, can be safely employed in child patients due to its non-  ionising nature and offers both qualitative and quantitative  assessments, and the digital model can be employed in the  clinical setting immediately. The disadvantages include the  cost, long time that is required for patient preparation and  data acquisition and inability to measure bony or interactive  landmarks.   Cephalometric analysis aids in evaluating the maxillary posi-  tion and its possible implications on the patient’s nose [21]  (Fig. 76.5b). The need for any maxillary advancement sur-  gery and the importance of performing it before any rhino-  plasty surgery should be conveyed to the patient.  Cephalometric analysis also allows for evaluation of chin  position [21].   CT scans of the paranasal sinuses in axial and coronal views  help in defining the deformation of the septum as well as  other intra-nasal structures. CBCT is an attraction alternative  to CT with regard to decreased ionising radiation to the  patient and image quality for hard tissues on par with CT. No  modalities other than CT/CBCT allow for evaluation of nasal  septum objectively [23] (Fig. 76.5c).    Facial casts have been employed by authors to study the  nasal morphology by direct anthropometry [24] (Fig. 76.5d).  The technique is found to be objective and cost-effective and    Fig. 76.3 (a—d) Important angular and linear measurements as traced from preoperative photographs can serve as a guide for preoperative surgical  planning    Fig. 76.4 (a—f) Standard photographic views for cleft rhinoplasty. (a) Frontal view. (b) Left lateral view. (c) Right lateral view. (d) Left lateral    allows precise recording of selected parameters as the soft  tissues are not deformed.    Some authors [25, 26] have also resorted to video recordings  that make assessment of movements possible and eliminates  the need for clinical photographs as these can be generated  from the video records. The disadvantages include increased  time and need for trained personnel with considerable coop-  eration from the patients.   Function is as important as nasal aesthetics. Functional  assessment can be established using rhinomanometry; how-  ever the usefulness of such an evaluation is limited.    Cleft rhinoplasty can be accomplished using either an open  or closed approach.    While primary rhinoplasty can be carried out using either  of the two approaches, definitive rhinoplasty is almost always  accomplished using an open approach.   The open approach allows for both superior visual control  and enhanced surgical exposure of all the abnormal compo-  nents facilitating their anatomical reconstruction under direct  vision. Furthermore, the approach facilitates nasal sculpting  either by suturing or by introduction and fixation of different  types of grafts. The approach also helps in saving time when  compared to the closed approach. When employing the open  approach, a combination of bilateral marginal incisions with  an inverted V mid-columellar incision is preferred among  most surgeons [27] (Fig. 76.6a, b).   Sometimes, additional skin needs to be recruited in the  columella. In such cases, the typical external columellar inci-  sion can be modified. When addressing the unilateral cleft  nasal deformity, columellar lengthening can be achieved  with the help of an asymmetric V to Y incision on the side of  the cleft. The V to Y incision is made in the midline, recruit-  ing the skin from the upper lip into the columella in cases of  bilateral cleft nasal deformity. A viable alternative incision in  cases of bilateral cleft noses is an upper lip forked flaps  which achieve columellar lengthening together with narrow-  ing of the central segment [28].   Other viable options include the use of prolabium advance-  ment flap together with an Abbe flap, composite graft of skin  and auricular cartilage and skin rim rotation flap [29].    Fig. 76.5 (a-—d) Tools for preoperative patient evaluation for cleft rhi- position prior to cleft rhinoplasty. (c) (1 and 2): Axial and coronal CT  noplasty. (a) Three-dimensional model of the face. (b) Lateral cephalo- scan views allow for evaluation of the nasal septal deviation objectively  gram for cephalometric analysis for evaluating the maxillary and chin (white arrows). (d) Facial cast for evaluating the nasal morphology    Fig. 76.6 Open approach for cleft rhinoplasty. A combination of inverted V (a, b) transcolumellar and bilateral marginal incisions is typically  employed. (a) Marking of the incision. (b) Skeletonisation of the nose using the above incision    Fig. 76.7 (a, b) Tajima and Maruyama reverse U incision for correction of nostril asymmetry. (a) Marking of the reverse U incision on to the  external nasal skin on the right side of the nostril. (b) Correction of nostril asymmetry following closure (also see Fig. 76.17)    Most patients with unilateral cleft nasal deformity are  often disturbed with the nostril asymmetry that accompa-  nies such a deformity. This has been addressed using a  reverse U incision as described by Tajima and Maruyama  in 1977 [30]. The technique involves extending the mar-  ginal incision into a rim incision at the point of the alar  web. The skin of the web is incorporated with the LLC  flap and vestibular skin, and the flap is suspended both  medially and cephalically from the LLC to the ipsilateral  ULC and the septum using sutures (Fig. 76.7a, b). This  helps in recruiting the external skin of the alar web to the  vestibular lining which also helps in addressing the issue  of deficient vestibular skin associated with unilateral cleft  noses. This incision is well accepted among surgeons for  correction of nostril asymmetry.    The aim of the surgery is to attain symmetry of the nasal tip  and alar base.    The literature has reported a number of techniques for  achieving symmetry in unilateral cleft nasal deformities pri-  marily [15, 31]. The salient points that are common to most  of these techniques include:    ¢ Completely freeing the soft tissue attachments of the alar  base from the pyriform aperture and maxilla for symmet-    rical repositioning of the retro-positioned alar base on the  cleft side.   ¢ Nasal tip plasty is carried out to increase the nasal tip  projection. This is made possible by utilising the  incisions for lip repair. Dissecting through these inci-  sions, the skin overlying the LLC’s is dissected with  the help of medial and lateral tunnels, and the cutane-  ous attachments of the lateral crura are separated [1]  (Fig. 76.8a).   ¢ Repairing the caudal septum by attaching it to the anterior  nasal spine.   e Finally, following complete closure of the lip and reposi-  tioning of the alar base, the LLC is secured in the new  position using either transnasal sutures or nasal bolsters  [32]. These sutures help in recreating the cleft side dome  thereby increasing the nasal tip projection and improving  the tip symmetry (Fig. 76.8b).    In bilateral cleft nasal deformities, the retro-positioned alar  bases are released from the nasal lining laterally and posi-  tioned symmetrically by securing the nasalis muscle to the  nasal septum on both sides. The nasal muscular ring is recon-  structed as performed in the unilateral cleft noses. Nasal tip  surgery is not performed at this stage but is carried out at the  time of intermediate rhinoplasty [21].    Fig. 76.8 (a, b) Schematic representation of primary rhinoplasty in a  unilateral cleft lip nasal deformity case. (a) Dissection for access to  crura utilising the incisions for lip repair. (b) Recreating the cleft side  nasal dome using transnasal sutures for better symmetry and projection.  The sutures are made to pass through the nose, vestibular lining and    LLCs and through the nasal skin before being reintroduced through the  nasal skin and ULC and sutured down within the nasal vestibule. It is  important to reintroduce them through the same hole they exited to pre-  vent necrosis of the nasal skin    Fig. 76.9 (a-d) A case of unilateral cleft nasal deformity in a 6-year- abnormal position of the LLC on the cleft side is corrected using an  old child managed using intermediate rhinoplasty. (a) Preoperative open approach (inverted V transcolumellar incision) and transnasal  frontal view. (b) Preoperative basal view showing the abnormal posi- sutures (black arrow). (d) Postoperative basal view showing symmetri-  tion of LLC on the cleft side (Left). (c) Postoperative frontal view. The cal positioning of the LLC on the cleft side (black arrow)    In cases of asymmetric position of the LLC on the cleft  side, an open approach is usually preferred that exposes the  LLCs bilaterally so that the geometric differences between  the two sides can be appreciated and subsequently corrected  using suture techniques followed by closure along the colu-  mellar incision [33].   In cases of lateral vestibular webbing, a V/Y-type incision  or a back cut can be carried out to affect the lateral nasal  sidewall lengthening which will subsequently bring the LLC  forward [1].    In such cases, intermediate rhinoplasty corrects the depressed  LLCs as well as affects lengthening of the short columella  [1, 34] (Fig. 76.10a, b). An open approach is employed for  correction of the above-mentioned scenarios. Following  exposure of the LLCs, the angle of divergence between the  domes is decreased using transdomal suture, helping in  increasing the projection of the nasal tip [34].    Fig. 76.10 (a, b) A case of bilateral cleft nasal deformity in a 5-year-  old managed using intermediate rhinoplasty. (a) Preoperative basal  view showing the abnormal position of the LLCs as well as short colu-  mella (black arrow). (b) Postoperative basal view. One can appreciate    Despite an excellent primary rhinoplasty, secondary defor-  mities coupled with scarring are bound to occur. These issues  are tackled upon by definitive rhinoplasty. The surgeon’s  skill and his expertise will ultimately decide the success of  primary cleft lip nose repair and the severity of secondary  deformities. The success of definitive rhinoplasty depends on  addressing every component of the deformity in a systematic  manner beginning with the nasal base and ending with the  alar base reduction.    Creating a strong base for the nose represents the prelimi-  nary step in correction of either unilateral or bilateral cleft  nasal deformity, the foundation for which is laid down at the  time of primary cheilorhinoplasty with the approximation of  the nasal floor with the lip. This is followed by addressing    lengthening of the columella that is achieved (black arrow). The correc-  tion of LLCs is also affected bilaterally. An open approach was utilised  with bilateral reverse U incision to correct the horizontal orientation of  the nostrils    the skeletal deficiency in the maxilla and premaxilla and  correction of the retro-positioned alar base. In some cases,  the nasal sill and the nasal base might still have to be aug-  mented at the time of secondary rhinoplasty using local tis-  sue flaps [35].    The caudal septum is seen to deviate to the non-cleft side,  bowing away from the anterior nasal spine with resultant  nasal airway obstruction. This requires resection of this  portion of the septum, maintaining at least | cm dorsal,  and caudal septal segments in the form of a L strut to help  in preserving the nasal tip and the dorsal support [21] (Fig.  76.11a—i). When doing so, more than 40% contact point  must be allowed between the crest of the maxilla and L  strut which helps by subjecting the septum to decreased  load forces thereby preventing nasal deformities like sad-  dle nose deformity or ptosis of the nasal tip from develop-  ing in the future. It is observed in most cases that despite  resecting the deviated portion of the septum, the L strut  continues to remain deviated due to residual memory that  is present in the L strut. In such cases, sutures can be  placed through the ULC and the septum applying force in  the direction opposite of the deviation to aid in correcting  the asymmetry [36]. In cases of severe septal deviation,  one needs to resort to using caudal septal extension graft  as struts along the dorsal margins followed by surgical  repositioning of the caudal septum [37, 38] (Fig. 76.11).  The resected portion of the septal cartilage can itself be  used as a spreader graft. In cases where the resected septal  cartilage is inadequate, one can use rib cartilage as a  spreader graft. The caudal portion of the L strut is secured  to the anterior nasal spine with the help of sutures. Some  surgeons also prefer to make a notch in the anterior nasal  spine to which the L strut can be secured. If there exists  any residual memory in the septal cartilage after securing  it to the nasal spine, it can be relieved by cartilage scoring  with the help of a no. 15 blade.   Access to the caudal nasal septum is achieved using an  open approach and by dissecting between the medial crura of  the LLCs [21]. From this point onwards, a sub-perichondrial  flap can be developed. Make sure that the dissection is in the  proper plane. The blue appearance of the septal cartilage  serves as a guide to correct plane of dissection. The mucop-  erichondrial flap should be cautiously raised without perfo-  rating the surrounding mucosa to provide superior coverage  for a large septal extension graft especially from the rib.    The middle third of the nose has poor support on the side of  the cleft and therefore the ULCs tend to collapse resulting in  internal valve dysfunction which affects the patient’s ability  to breathe normally. In such instances, spreader grafts placed  between the septum and ULCs on either side and stabilised  using sutures can help open the internal nasal valve and  improve breathing [39, 40] (Fig. 76.11i).    Once the caudal septum is stabilised, attention is shifted to  the correction of asymmetric LLC and the nasal tip complex.  Various techniques are advocated for the same.    ¢ Cephalic trimming: Wide LLCs can make the nose  appear asymmetric. In such cases, following surgical  exposure of the LLCs via an open approach, small  cephalic strips of LLCs can be excised advocating more  excision on the larger side and leaving at least 5 mm for  support. This manoeuvre narrows a bulbous nasal tip and  improves symmetry. Cephalic trimming is followed by  correction of the septal deviation by resection and replace-  ment (Fig. 76.12a).   e Septal extension graft: A strong septal extension graft  helps in providing support to the nasal tip and improves  the tip projection by rotating an acute nasolabial angle  which is the consequence of tip ptosis back to normal  (22, 41]. The graft is ideally sutured in between the  medial crura of LLCs and the caudal septum  (Fig. 76.12b). Prior to suture stabilisation of the septal  extension graft, the medial crus of LLC on the cleft  side is advanced superiorly to match the vestibular  dome height of the non-cleft side. This is then secured  to the extension graft using mattress sutures  (Fig. 76.12c). In cases where spreader grafts are used  to relieve the internal nasal valve collapse, the exten-  sion graft can be secured to the spreader grafts. In such  cases, the base of the nose is fortified with bolster  sutures from medial crus to the septal extension graft.  The strut (extension graft) is ideally placed slightly  behind the medial crura to prevent the columella from  either looking too wide or feeling too firm for the  patient [39]. A good tip support entails extension of the  septal extension graft for at least 4-5 mm beyond the  septum maintaining a thickness of at least | mm. This  also helps to resist deprojection from the resulting scar  tissue that will form in this region.    Fig. 76.11 (a-i) 22-year-old patient with unilateral cleft lip and palate  before (a—c) and 2 months after (d-f) open rhinoplasty performed to  correct the severely deviated caudal septum. (g) Intraop picture show-  ing batten grafting. (h) Resection of septal cartilage in cases of severely    deviated nasal septum, maintaining an L shaped contact (black arrow)  for preserving tip and dorsal support. The resected portion can be uti-  lised as a septal extension graft (green arrow). (i) Spreader grafts placed  between ULCs and nasal septum (black arrows)    Fig. 76.12 (a—c) Schematic representation of techniques for correc- for improving the symmetry and projection of the nasal tip. Dorsal  tion of asymmetric LLCs and nasal tip complex. (a1, a2) Cephalic trim- nasal augmentation is also been shown. (cl, ¢2) Lateral crural steal  ming (before and after). (b) Shield grafts, caudal septal extension grafts technique    e Lateral crural steal or advancement flaps: The medial  crus of the LLC on the cleft side is shorter in vertical  length, whereas the lateral crus is longer with a horizon-  tal orientation as compared to the non-cleft side. In such  cases, lengthening of LLC on the cleft side is achieved  using the lateral crural steal technique which requires  cutting of the longer part of the lateral crus of the LLC on  the cleft side and shorter part of the lateral crus of LLC  on the non-cleft side [39] (Fig. 76.12b). This facilitates  utilisation of the longer crural flap on the side of the cleft  for increasing the nasal tip projection on the cleft side  thereby contributing to improved nasal tip symmetry.  The lateral crura are then reconstructed using either  robust cartilage struts or batten grafts in onlay or inlay  fashion.   e Shield graft: These grafts are utilised to accentuate the  tip projection further as well as improve the symmetry  and tip shape (Fig. 76.12b).    In bilateral cleft nasal deformities, LLCs of either side  need repositioning with tip suture techniques. In cases of  weak cartilages, septal extension grafts as columellar struts  as well as in onlay position need be used for ideal projection  [42]. Large nasal tip can benefit from cephalic trimming of  both LLCs. The goal is to decrease the angle of divergence  between the domal points of the lower lateral cartilages, cre-    Alar batten graft from septal cartilage  sutured on to the LLC    Fig. 76.13 Alar batten grafting demonstrated in a case of unilateral  cleft nasal deformity. The graft fortifies the LLC and removes the con-  cavity of the same (Refer Fig. 76.171)    ate a more defined nasal tip and provide a strong nasal frame-  work for better tip projection.    The LLC on the cleft side has poor skeletal support on the  medial and lateral sides which makes the LLC concave with  an introverted contour to the ala [43]. This concavity can be  managed with different techniques, viz. suture techniques  using horizontal mattress sutures, underlay alar batten  grafts, onlay grafts and autocartilage flaps [44]. The lateral  crus of LLC can also be dissected from the underlying ves-  tibular skin, removed, flipped and resutured in a convex  fashion.   Alar batten grafts either are placed below the residual  lateral crus as underlay graft or can be placed above it as an  onlay graft. This graft strengthens the lateral crus of the  LLC and removes the concavity of LLC [39] (Fig. 76.13).  Suture techniques such as horizontal mattress sutures also  strengthen and flatten the lateral crus of the LLC. Lastly,  the cephalic margin of the LLC can be made into an  advancement flap which can be advanced to provide sup-  port to the remaining LLC. Each of these techniques pro-  vides support to the lateral crus of the LLC and fortifies the  external nasal valve.    The following issues are observed when addressing this area  in definitive rhinoplasty.    ¢ Flat and under-projected dorsum deviating away  from the cleft: The authors’ preferred technique for  addressing this issue is by using a dorsal onlay graft from  rib or modified Turkish delight. In modified Turkish  delight technique, the authors use morselised Medpor  mixed with autogenous blood and wrapped in Surgicel to  affect dorsal nasal augmentation [45] (Figs. 76.12b and  76.14a—d). This cancels out the need to carry out harvest-  ing of the rib cartilage and there eliminates the donor site  complications associated with the same. Although sili-  cone implant can also be used for this purpose, there is  increased possibility of infection, graft migration or  displacement or possible extrusion. It should be noted  that the dorsal nasal pocket dissected should just accom-  modate the implant so that the implant fits snugly with-  out much displacement or migration.  Dorsal humps: The dorsal hump usually peaks at the  region of the rhinion where the nasal bones and ULC join.    Fig. 76.14 Addressing the nasal dorsum and nasal osteotomies. A case _ and lateral. (e1, e2) Schematic representation of dorsal hump reduction.  of flat and under-projected dorsum managed using modified Turkish — (f, g) Schematic and clinical lateral nasal osteotomies  delight technique. (a, b) Pre op frontal and lateral. (c, d) Post op frontal    Dorsal hump should be addressed in conjunction with  other aspects of the nose, or else an open roof deformity  will be the consequence. The correction is carried out by  reduction of the bone by rasping and the ULC using either  scissors or number 15 blades (Fig. 76.14e).   Thick and wide nasal bones with deviation towards  the non-cleft side with wide dorsum: Such cases  require either lateral or paramedian osteotomies to nar-  row the dorsal width and bring about symmetry. The  authors’ preferred technique for lateral osteotomies is by  introducing a 2—3 mm osteotome transcutaneously to  create micro punctures along the planned osteotomy  going from low to high [42] (Fig. 76.14f, g). The same  can also be carried out by introducing the osteotome  transnasally. If this does not affect narrowing of the dor-  sum adequately, then the authors resort to paramedian  osteotomies to create an open roof deformity followed by  in-fracturing the nasal bones. This manoeuvre almost  always requires placement of spreader grafts to prevent  collapse of the internal nasal valve.    Cleft noses whether unilateral or bilateral present with skel-  etal deficiency in the region of the premaxilla and piriform  rim which brings about posteroinferior displacement of the  nose. If this area is left unattended, the final result is bound  to be asymmetric despite addressing all the other aspects of    rhinoplasty well [39]. This area can be augmented using a  portion of the rib graft and securing it with a screw  (Fig. 76.15). This allows for improving the anterior projec-  tion. Other options include the use of silicone implant, corti-  cal one or fat grafting [21].    The nasal alae in cleft noses as discussed previously are usu-  ally displaced in a lateral and inferior direction. Correcting  the abnormal orientation of the nasal alae represents the con-  cluding steps in definitive rhinoplasty. This is usually  achieved using two techniques, viz. V to Y advancement and  Weir procedure (alar resection) along the alar facial groove  [46-48]. These two procedures need to be supplemented  with augmentation of the piriform rim as well as vertical  enlargement of the nostril on the cleft side in order to achieve  true symmetry. Vertical enlargement of the nostril can be  achieved using skin grafts or composite grafts just inside the  ala. Superior results are possible despite not addressing the  nostril except from the basal view which will make the  vertical height discrepancy of the nostril evident. Weir proce-  dure is used in cases of excess skin laterally and allows for  symmetrical correction of the alar base on the cleft side nos-  tril which is usually longer and elongated (Fig. 76.15a—g). It  also provides access for carrying out augmentation of the  piriform rim using grafts. Nostril retainers are often sutured  in place for the purpose of helping in moulding and main-  taining the nasal sill.    Fig. 76.15 (a—f) Piriform rim augmentation and alar base reduction using Weir procedure. (a, b) Pre op and post op basal views. (c) Alar base  resection. (d) Peri alar resection. (e) Closure. (f) Piriform rim augmentation    Grafts are pivotal to the long-standing success of definitive  rhinoplasty in terms of nasal aesthetics and function.  Autologous tissue is the norm and always preferred over syn-  thetic substitutes like Medpor and silicone which presents  with higher incidences of infection, displacement as well as  possible extrusion. Among the autologous options available,  cartilage (harvested from septum, auricle or rib) and bone  (harvested from cranium, rib or iliac crest) are widely used.   Cartilage grafts harvested from the septum have the  advantage of being located in the same surgical field, requir-  ing no additional incisions and therefore preventing any  additional donor site morbidity. Furthermore, simultaneous  correction of septal deviations is possible with the use of this  graft. The disadvantages include minimal amounts of carti-  lage available for grafting and presence of residual memory  subjecting it to deformation. When the amount of available  septal cartilage is inadequate, auricular cartilage can be the  source of grafting. It may offer a large area for graft harvest-  ing, and usually does not induce local sequelae. When larger  amount of cartilage is needed especially for the purpose of  dorsal augmentation, rib cartilage is an excellent source  especially from the right seventh, eighth or ninth rib. This  cartilage is present in abundance, is quite sturdy and robust,  resists deformation by scar contracture, is easy to shape and  also provides superior support for optimising the nasal pro-  jection [39]. The disadvantages include graft warpage,  increased operating time, visible external scar, post-operative  pain and risk of pneumothorax. Another disadvantage is  ossification of cartilage in older patients [39].   Cartilage grafts are classically divided into contouring  grafts and structural grafts.    These grafts are added to the native osteocartilaginous nose  in the coronal plane to improve upon the existing nasal aes-  thetics. Two most common sites for placement of these grafts  are the dorsum and the infratip regions of the nose which  help in optimising the tip projection. These grafts are stabi-  lised using either resorbable or non-resorbable sutures or  glue. Examples of contouring cartilage graft include dorsal  onlay graft or shield-type tip graft.    ¢ Dorsal onlay graft: It is used for dorsal nasal augmenta-  tion. The rib cartilage is the obvious choice. We have also  utilised the modified Turkish delight (diced Medpor    mixed with autologous blood and wrapped in Surgicel)  for the same purpose with reasonable success.   e Shield-type tip graft: Onlay shield grafts help in defin-  ing the nasal tip better, optimise the tip projection as well  as provide support and hide any minor tip asymmetries.    These grafts strengthen the cartilaginous framework of the  nose which improves upon the existing nasal function. These  grafts are placed in the sagittal plane and display long-term  stability especially when an open approach is used to secure  the same. They allow structural and functional reconstruc-  tion of the nasal tip in cases of definitive rhinoplasty.  Examples include spreader grafts, alar batten grafts, colu-  mellar strut grafts, etc.    e Spreader graft: Spreader grafts serve to open the internal  nasal valve and improve nasal breathing. Options for har-  vest include the septal or rib cartilages. The graft can also  be made to extend more caudally making it to function  like a strut for improved nasal tip support as well as to  straighten and stabilise the septum. Severe septal devia-  tion can be also corrected by placing the grafts along the  dorsal septum while reattaching the caudal strut to the  nasal spine between the medial crura by suture fixation.   e Alar batten graft: Batten grafts serve to strengthen the  lateral crura of the LLC. The curved portion of the rib  cartilage can be used to the advantage for harvesting these  grafts. They are stabilised to the LLC and the strut to  mimic the natural convex form of the external nasal valve  and provide structural support. These grafts are critical  for the correcting alar retraction whenever present.   ¢ Columellar strut graft or septal extension graft: Such  a graft provides support to the nasal base and can be a  platform upon which the nasal tip can be suture stabilised.  It can be harvested from the septal cartilage or from the  interior of the rib cartilage.    Nakamura N has devised a treatment strategy for both unilat-  eral and bilateral cleft noses that addresses each anatomical  and pathological abnormality that is seen in either scenarios  [49].    The pathologic abnormalities that have been previously  mentioned are best explained by Nakamura N by comparing  the unilateral cleft nose to a house that is been built on a  slope. The mid-pole of the house can be thought to be nasal  septum, whereas the roof is the LLC and skin, the lateral pole  is the vestibule and the base of the house is the maxillary  bone. As the house is present on the slope, the mid-pole and  the roof incline towards the downward side. In such cases, a  straight house can be built on the slope by up righting the  centre pole in the centre of the pillar with expansion of the  lateral pole and by lifting the roof upward [49] (Fig 76.16a).   Nakamura N’s treatment strategy addresses each anatomi-  cal and pathological abnormality that causes the main defor-  mities in unilateral cleft nasal deformity listed in Table 76.1.  The author’s steps in definitive rhinoplasty consist of an open  approach; septoplasty; repositioning of the lower lateral carti-  lage; medial and upward advancement of the lip and nose  components, the nasal vestibular tissues, the nasal ala, nasalis  muscle and the upper part of the lip including orbicular oris  muscle; and nasal vestibular expansion with or without bone  graft [50].    The pathologic abnormalities that have been previously  mentioned are best explained by Nakamura N by likening  the bilateral cleft nose to a house that is compressed by  stress. In such cases, normal form of the nose can be created  by extending the centre pole at the centre, advancing the roof  upwards and extension of the lateral poles on each side  (Fig. 76.16b). It is very critical to relieve the stress which in  other words means relieving the pull on the nasal tip due to  columellar skin shortage [49].   The treatment strategy devised by Nakamura N is based  on the principle that the ideal technique of definitive rhino-  plasty should minimise damage to either or both the upper  and lower lip tissue. This strategy also addresses each ana-  tomical and pathological abnormality that causes the main  deformities of the bilateral cleft lip-nose as shown in  Table 76.2. Therefore, the author’s secondary correction  involves open rhinoplasty, repositioning of the lower lateral  cartilages, a caudal septal extension graft, medial and upward  advancement of the lip and nose components, nasal vestibu-  lar expansion and columella lengthening using a nostril rim  rotation flap, if necessary [51].    Fig. 76.16 (a, b) Simplifying cleft nasal anatomy by Nakamura N. (a) Unilateral cleft nasal anatomy. (b) Bilateral cleft nasal anatomy    Anatomical  Nasal pathological  deformities abnormalities Secondary correction  Deviated ¢ Deviation of ¢ Dissection around  columella maxillary midline anterior nasal spine  ¢ Deviated septal ¢ Reposition of the  cartilage inferior base of septal  cartilage if necessary  Depressed and Distally and ¢ Freeing and  deviated nasal downwardly repositioning of LLC by  tip dislocated LLC on overlapping on ULC  the cleft side ¢ Caudal septal extension  ¢ Growth disturbances graft  of septal cartilage  Wide and snub * Retro-positioned ¢ Secondary bone graft if  nasal alaonthe anterior maxillary necessary  cleft side wall ¢ Supra-periosteal  ¢ Dislocation of the dissection around  attachment of piriform margin  nasalis muscle ¢ Reposition of the nasalis  muscle by medial  upward advancement of  nasolabial components  Flat and V ¢ Webbing of the rim = * Bilaterally symmetric  shaped nostril skin reverse U incision    ¢ Shortage of nasalis  vestibular lining  ¢ Disconnection of  orbicularis oris  muscle  Nakamura N et al., J Oral Maxillofac Surg 2010; 68: 2248 [50]    Over the past few years, there has been an increased empha-  sis on the functional rather than aesthetic outcomes in cleft  rhinoplasty [52]. Techniques like primary cleft rhinoplasty  and naso-alveolar moulding have also been laden with com-  plications. Although several studies have compared the dif-  ferent techniques of rhinoplasty to determine which  technique offers the best surgical outcome, these studies lack  standardised objective measurements to draw any meaning-  ful conclusions.   The data regarding functional outcomes in cleft rhino-  plasty is also sparse. In one of the prospective studies with 68  cleft patients, the authors evaluated aesthetic and respiratory  outcomes at two intervals, viz. pre- and 6 months postopera-  tively using an active anterior rhinomanometry, rhinore-  sistometry and acoustic rhinometry [53]. The study showed  significant improvement in many parameters. The authors   ¢ Reposition of the nasalis  muscle by medial  upward advancement of  nasal alar component    Nakamura N et al, J Cranio Maxillofac Surg 2011; 39: 305 [51]    concluded that while aesthetic improvement of the cleft nose  is a goal, which can be achieved with regularity, nasal respi-  ration still seems to be a challenge in cleft patients. This  study highlights the need of recording functional data to  study about the effects of surgery.   The outcome that is clearly documented in literature is  the high satisfaction rates in patients undergoing surgery  for cleft nose deformity. A study incorporating 35 patients  with cleft nasal deformity was carried out by Sandor and  Ylikontiola [54]. An open approach of rhinoplasty fol-  lowed by alar base relocation and asymmetric nasal tip  augmentation with auricular cartilage grafts was carried  out in all patients. The patients’ level of satisfaction was  recorded in the form of a survey and interview 2 years  post-surgery. A visual analogue scale (VAS) numbered  0-10 was also used by the patients to grade outcome com-  pared to preoperative appearance at four anatomic sites.  The study demonstrated highest improvements in VAS    score for the tip, followed by alar position and dorsum  and symmetry of nostrils. They noted that all patients  were willing to undergo such procedure for a second time,  if necessary. Two more studies have also reported high  patient satisfaction rates for patients undergoing surgery  for cleft nasal deformities [55, 56].    Although secondary cleft rhinoplasty is considered the ulti-  mate revision rhinoplasty, in certain cases like those involv-  ing asymmetries or scarring, the patient’s overall functional  and aesthetic outcome may be compromised necessitating  further revisions. It is important to remember that the prin-  ciples that are followed in revision rhinoplasties are similar  to those followed in primary and secondary rhinoplasties.  The emphasis should be on early recognition after the defini-  tive rhinoplasty so that revision is possible before scarring  sets in.    The complications noted in cleft rhinoplasty are similar to  those noted in the traditional open rhinoplasty in non-cleft  patients. As cartilage grafts are employed, there exists a pos-  sibility of infection. Over the long term, the grafts, whether  autologous, allogenous or alloplastic, can demonstrate fail-  ure. There is no difference in the risk of bleeding between  cleft rhinoplasty and traditional rhinoplasty. All patients  should be made aware of possible need for secondary rhino-  plasty, need for revision either major or minor, existence of  nostril asymmetry, visible scars, necrosis of the skin, nasal  system dysfunction and morbidity associated with the donor  site. One can fail to create the nasal contour as desired as  well as fail in creating a normal looking appearance, and  these are very common findings in cleft rhinoplasty.    Cleft rhinoplasty as a surgical procedure is often complex  and complicated due to multiple surgical procedures that  the patient needs over the years. Despite all the challenges  that the procedure offers, the final surgical outcome could  serve as a life changer for the patient in terms of aesthetics,    function as well as symmetry. One should stick to the con-  cepts of restoring symmetry and definition to the nasal tip  and alar base, realigning and re-establishing the patency of  nasal airway and preventing scarring and webbing from  jeopardising the outcome. All cases have to be thoroughly  planned preoperatively using the right assessment tools,  and the surgery should be executed to near perfection. An  increased emphasis should be placed on carrying out a pri-  mary rhinoplasty procedure keeping in mind that a defini-  tive rhinoplasty will almost always be required to fine-tune  the results.    Case 1 Figure 76.17 represents a case of right unilateral cleft  nasal rhinoplasty in a 20-year-old female managed with  definitive rhinoplasty. The patient presented with the chief  complaint of crooked nose and difficulty in breathing from  the right nostril. The patient was subjected to thorough clini-  cal examination of both the external and internal nasal anat-  omy. The following features of the cleft nose were noted:  deviated nasal dorsum away from the cleft in frontal view and  horizontally oriented right nostril in basal view with deviated  base of columella to the left. Deviated caudal septum was also  noted with difficulty in breathing in the right nostril. Concavity  of the right LLC was also observed in the basal view. In the  lateral view, tip ptosis was observed. The patient was sub-  jected to open rhinoplasty approach using inverted V trans-  columellar incision with incorporation of the reverse U  incision on the right side to correct the right nostril asymme-  try. Following skeletonisation of the nose, dissection was car-  ried between the medial crura of LLCs to expose the caudal  septum which was resected to correct the septal deviation.  The authors would like to stress on the importance of address-  ing the nasal septum almost always in all cases when per-  forming a definitive rhinoplasty in a unilateral cleft nasal  deformity. Substantial amount of septal cartilage was har-  vested to be used as a caudal extension graft to correct septal  deviation as well as to improve tip projection. The cartilage  was also utilised as an alar batten graft sutured to the lateral  crura of LLC of the right side to correct the concavity of the  right LLC. Bilateral spreader grafts were sutured between the  ULC and the septum to improve the nasal breathing by  improving the internal nasal valve function. Lateral crural  steal was performed on the right side to maximise the projec-  tion of the nose, and further tip projection was achieved using    cartilages. (f) Exposure of nasal septum. (g) Spreader grafts placement  bilaterally. (h) Columellar strut. (i) Columellar reconstruction and alar  batten graft. (j) Intra op frontal. (k) Intra op basal. (1) Post op frontal.  (m) Post op lateral. (n) post op basal    Fig. 76.17 (a—n) Clinical Scenario 1: A case of unilateral cleft nasal  deformity in a 20-year-old female managed with definitive rhinoplasty.  (a) Pre op frontal. (b) Pre op lateral. (c) Pre op basal. (d) Incision mark-  ing (inverted V with Tajima modification). (e) Exposure of lower lateral    interdomal sutures. The deviated nasal dorsum away from the  cleft was corrected using transcutaneous lateral osteotomies  bilaterally in a low to high fashion. Lastly, right alar base  reduction using a Weir procedure was carried out to achieve  symmetry between the two alar bases. Closure of the incision  was carried out using 4-0 Vicryl Rapide sutures. Comparison  of the pre- and 4 weeks postoperative photographs demon-  strate significant improvement in the nasal aesthetics. The  patient is very satisfied with the overall result and has no  complains of difficulty in breathing.    Case 2 Figure 76.18a—k represents a case of bilateral cleft  nasal deformity in a 6-year-old male managed with interme-  diate rhinoplasty. On clinical examination, all the features  characteristic of bilateral cleft nasal deformity was evident  some of which included wide dorsum with bifid nasal tip,  horizontally oriented nostrils, tip ptosis and short columella  with a wide base. The septum was classically midline.    Intermediate rhinoplasty was planned via an open approach  in this case. An inverted V transcolumellar incision with  bilateral reverse U incisions was planned to correct the hori-  zontal orientation of the nostrils. The goal of the surgery was  to primarily affect symmetric positioning of LLCs as well as  to increase the length of the columella. Following exposure,  dissection of the LLCs was carried out. A columellar strut  from medpor was utilised which served to increase the tip  projection. Symmetric positioning of LLC’s was affected  and sutured in place using horizontal mattress sutures.  Transdomal sutures were also added to correct the bifid tip  and decrease the angle of divergence between the alar domes.  A modified Turkish delight graft was utilised for the purpose  of dorsal nasal augmentation, and closure was affected with  vicryl rapide sutures. It is important to note that any septal  procedures were avoided to prevent growth disturbances.  The pre- and 2 months postoperative photographs reveal a  dramatic improvement and achievement of the preoperative  goals.    Fig. 76.18 (a-k) Clinical Scenario 2: A case of bilateral cleft nasal (f) Columellar strut for columellar reconstruction. (g) Modified Turkish  deformity in a 6-year-old male managed with intermediate rhinoplasty. delight for dorsal augmentation. (h) Closure. (i) Post op frontal. (j) Post  (a) Pre op frontal. (b) Pre op lateral. (c) Pre op basal. (d) Exposure of __ op lateral. (k) Post op basal    . Shih CW, Sykes JM. Correction of cleft lip nasal deformity. Facial    . Bryd HS, El-Musa KA, Yazdani A. Definitive repair of the unilateral    . Fisher DM, Sommerlad BC. Cleft lip, cleft palate and velopharyn-    . Huffman WC, Lierle DM. Studies on the pathologic anatomy of the    . McComb HK, Coghlan BA. Primary repair of the unilateral cleft lip    nose. Completion of a longitudinal study. Cleft palate Craniofac J.  1996;33:23-31.    . Bernstein L. 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If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.   Since ages, congenital deformities were considered evil and  wizard, and infants were abandoned to die in isolation. Jean  Yperman (1295-1351) valued the congenital origin of the  clefts. He additionally characterized the different types of  the condition and set out the standards for their treatment.  Fabricius ab Aquapendente (1537-1619) and William His of  college of Leipzig independently researched and published  embryological premise of clefts [1].   Laroche was the first to separate between common cleft  lip or harelip and clefts of the cheek. Further qualification  was made in 1864 by Pelvet, who isolated oblique clefts  including the nose from the other cheek clefts, and drawing  on Ahlfeld’s work, in 1887 Morian gathered 29 cases from  the writing, contributing 7 instances of his own. Morian per-  ceived three unique groups of oblique facial clefts. From that  point forward, astounding audits have been composed by  Griinberg in 1913, Boo-Chai in 1970, Paul Tessier in 1976  [2] and Millard in 1977 [3].   Craniofacial cleft by definition is “a fissure of the soft tis-  sues that corresponds as a general rule with a cleft of the bony  structures.” [1] The greatest research on craniofacial clefts  was finished by Tessier and is credited for the formation of  the craniofacial surgery for establishing the framework of the  advanced craniofacial surgery by fundamentally breaking  down facial clefts and portraying facial osteotomies [4].   Craniofacial clefts are significant clefts affecting the face,  cranium, or both. These clefts cause distortion of the face  and cranium with lacks or abundances of tissue that cleave  anatomic planes in a straight fashion [2]. Craniofacial clefts  exist in changing degrees of seriousness, and practically  every one of them happens along the anticipated embryo-    S. Gosla Reddy (2) - A. P. Acharya  GSR Institute of Cranio-maxillofacial & Facial Plastic Surgery,  Hyderabad, Telangana, India    © The Association of Oral and Maxillofacial Surgeons of India 2021    logic lines. These clefts can be either complete or incomplete  and can seem alone or in relationship with other facial clefts.  Seriousness of craniofacial clefts fluctuates extensively, run-  ning from a scarcely distinguishable indent on the lip or on  the nose or a scar-like structure on the cheek to an extensive  partition of all layers of facial structures. Notwithstanding  one parted sort can show on one side of the face, while an  alternate kind is available on the other side [2, 3].   Craniofacial clefts need comprehensive rehabilitation.  Past the physical consequences for the patient, they have  monstrous mental and financial impacts on both patient and  family, prompting disturbance of psychosocial working and  diminished nature of life [4, 5].   Cleft repair is a necessary part of the modern  craniomaxillo-facial surgical spectrum and remains a chal-  lenge on account of inadequate and contorted tissue (minor  to major) at the site of the deformity [6]. The outcomes are  additionally impacted by the short and long haul aesthetic  (soft tissue and facial skeletal appearance) [7] and useful  (occlusal and discourse) outcomes [8]. What’s more, the  kind of careful fix, the specialist’s abilities and the compli-  ance of the patient likewise, affects the stylish [9] and utili-  tarian [10]outcomes. The real test isn’t just understanding  the hereditary qualities [11], in addition to plan the standard  conventions for the surgery in these phenomenal kinds of  clefts [12].   Craniofacial clefts are a lot rarer than the simple cleft lip/  palate deformity [13]. The precise occurrence of craniofacial  clefts has not been exactly documented in view of their rar-  ity. However, the reported frequency of craniofacial clefts is  1.5-6.0 per 100,000 live births [14]. The occurrence of  uncommon craniofacial clefts contrasted with ordinary cleft  lip and palate may vary from 9.5 to 34 for every 1000 [15].    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1-15-1346-6_77    Lateral or transverse clefts of the lip are very uncommon  and have commonly archived to have a rate of 0.3% of 1.0%  of all of the facial cleft deformity spectrum (Boo-Chai 1969;  Hawkins et al. 1973; Bauer et al. 1982; Verheyden 1988;  Gleizal et al. 2007), or of 0.02% of live births (Kuriyama  et al. 2008) [16]. Median clefts of the lower lip are very rare  and only 68 cases have been accounted for till date [17].    Successful treatment of innate craniofacial defects depends on  an intensive comprehension of the embryologic procedures  prompting their development [18]. There are various interest-  ing highlights that plainly recognize craniofacial improvement  from the advancement of different tissues in the body.   One of these novel highlights is the double starting point  of craniofacial tissues: the skeletal framework and the vast  majority of the connective tissues, including veins, begin  from a gathering of cells called the cranial neural crest, while  the musculature and some parts of the skull begin from  mesoderm.   A second one of a kind component is the unit of intricate,  complementary tissue interactions between the neuroecto-  derm, the mesenchyme, and facial ectoderm that drive ordi-  nary advancement.   A third novel element is the extravagantly arranged mor-  phogenetic developments—brought about by both unin-  volved cell removal and dynamic cell movement—that  characterize head advancement. Any procedure that upsets  the rate, the planning, or the degree of these complex cell  conduct can result in a craniofacial birth imperfection.    Establishment and Fusion of the Facial  Prominences (Figs. 77.1 and 72.3)   The basic morphology of the face is established between the  4th and 10th week of human development. The face is  formed as a result of fusion of the midline frontonasal prom-  inence and three paired prominences, the maxillary, lateral  nasal, and mandibular prominences. Each of these promi-  nences is filled with cranial neural crest cells that originated  at different positions along the neural tube.   The frontonasal prominence gives rise to the forehead, mid-  line of the nose, the philtrum, the middle portion of the upper  lip, and the primary palate. Interruptions in frontonasal  growth often result in a bilateral cleft lip, where the primary  palate frequently “everts.” In the mildest cases, clefts involv-  ing frontonasal prominence-derived structures may be lim-  ited to a notch in the vermillion border of the lip. In more  severe cases, frontonasal clefts involve all of the tissues of  the lip, and these cases may most likely occur because of a  failure of fusion between the frontonasal and maxillary  prominences.   The lateral nasal prominences give rise to the alae of the  nose. Clefts that involve the side of the nose often result  from a failure in the fusion between the lateral nasal  prominences and either the frontonasal or the maxillary  processes.    Fig. 77.2 (a)Tessier classification for soft tissue clefting. (b) Tessier classification for bony clefting   The maxillary prominences develop into the upper jaw, the  facial halves, the upper lips, and the secondary palate. The  nasal passage is divided from the pharynx by the secondary  palate, which is formed from the neural crest cells. The pala-  tal shelves first drop vertically and then rotate into a horizon-  tal plane on the dorsal side of the tongue before fusing. The  epithelium of the palatal shelves sloughs off, with only the  basal layer of epithelium remaining to cover the later palate.   This develops into the lower jaw and lower lip. Clefts of the  lower jaw are very rare, presenting with a wide variety of  phenotypes, ranging from a vermillion notch on the lip to a  complete cleft involving the anterior mandible, chin, tongue,  and lower lip and occasionally involving midline structures  of the neck up to the manubrium sterni [19].    Development of the head and face contains a standout among  the most mind-boggling events among embryonic advance-  ment. Disturbance of this firmly controlled course can result  in a facial cleft where the facial primordia fail to meet and    form the suitable structures [20]. The definite instrument of  the cause of facial clefts is obscure, yet they are accepted to  have a multifactorial etiology including a mix of natural and  hereditary causes during embryonic development [21, 22]. In  India affiliation and healthful inadequacies in pregnant  mothers are the main cause of clefts [23].   The discussion is as yet in contention between the sup-  porters of Meckel who trusted that clefts were brought about  by a developmental arrest and Geoffroy St. Hilaire (1832)  who felt that amniotic groups were responsible [15].   Fogh-Andersen previously characterized hereditary fac-  tors in clefting, which have been affirmed by segregation  analysis [23]. Research in molecular genetics have identified  genes responsible for rare facial clefts which may be syn-  dromic and also for complex non-syndromic variants [24].   The non-syndromic types of orofacial clefts are likely  due to secondary gene-environment interactions [25].  Non-syndromic cleft is a heterogeneous disease entity  with candidate clefting loci on chromosomes [1, 2, 4, 6,  11, 14, 17, 19].    Infections. The offspring of mothers with toxoplasmosis,  rubella, or cytomegalovirus diseases display expanded  frequencies of facial clefts.   Maternal idiosyncrasies. Mothers of children with CLP  display an increased rate of phenylketonuria. The oculo-  auriculovertebral range has been seen with strange recur-  rence among neonates with mothers who are diabetic.  Numerous examinations have proposed maternal factors,  for example, age, weight, and general well-being, as  potential reasons for distortions.   Chemicals. Nutrient deficiencies are related with expanded  rates of CLP, which might be decreased with vitamin sup-  plementation for expectant mothers. Vitamin A, its sub-  sidiaries, and related compounds, for example,  isotretinoin, have been involved in the developments of  facial clefts and hemifacial microsomia [26].    Any maternal liquor consumption during pregnancy  increases the frequency of orofacial clefting [27]. The impact  of maternal smoking also may be responsible [28]. Multiple  studies have demonstrated that folate deficiency is related  with clefts. Pre-birth folic acid supplementation has shown  to diminish this hazard. At present, folic acid supplementa-  tion is the main empirical safeguard to diminish the fre-  quency of facial clefting [2].    An all-round grouping plan that completely envelops, pre-  cisely depicts, and coordinates all the different types of oro-  facial and craniofacial clefts does not exist [2]. Soemmering  (1791), Morian in 1886, Degenhardt (1961), the American  Association of Cleft Palate Rehabilitation (AACPR) (1962),  and Boo-Chai have made huge contributions in building up a  classification [29-32].    In 1976, Paul Tessier depicted an anatomical order frame-  work in which a number is doled out to every abnormality  based on its position with respect to the sagittal midline [33].   This framework has moved towards global acknowledg-  ment and allows reliable correspondence among clinicians  [34].   This classification involves the orbit as the principle refer-  ence point. Fifteen areas of clefting have been demonstrated  with discussion of their soft tissue and hard tissue involve-  ment [33] (Fig. 77.2a, b).   The numbered clefts relate the soft tissue features to  underlying bony involvement.    These have been verified by operative findings and more  recently preoperative 3D CT assessments [35]. The clefts are  radially distributed around the orbit with the midline 0 cleft  named as median facial dysrhaphia [33].   The no. 0 cleft is the most widely recognized of the craniofa-  cial clefts [36]. No. 0 and 14 is also called as midline cranio-  facial dysrhaphia. Clinically, this cleft shows up as an  absence of conclusion of the front neuropore [33].   It shows two variants: a true and false middle congenital  cleft, with or without related hypo- or hypertelorism [36].  Developmental cause of Tessier no. 0 isn’t evident; how-  ever, it is realized that midline facial deformities can be fol-  lowed to a period relating to the third week of gestation  [36]. The cleft expresses as a duplication of the crista galli  in frontal bone (“skull bifidum” and middle encephalocele),  and as nasal septal duplication, and cleft through the colu-  mella, maxilla, and lip [33]. This form of cleft may have  either a deficiency or abundance of tissue: with tissue agen-  esis and holoprosencephaly toward one side and frontonasal  hyperplasia and inordinate tissue (the hyperplasias) at the  opposing end. Midway inconsistencies with normal tissue  volume possess the center segment of the spectrum [37].   2. Bifid nose with wide columella and a wide furrow  in the nasal dorsum   4. Overprojected nose due to fibromuscular connec-  tion of the alar ligaments and the frontal bone   2. Absence of the philtrum of the lip, premaxilla, nasal  septum, columella, and the crista galli [33]   . Widened body of the sphenoid bone with separation  of the pterygoid plate [35]    Fig. 77.3 (a—c) Clinical subclassification of Tessier number 0. (a) Type I—Involving only vermillion not involving the white roll. (b) Type I—  Involving vermillion and white roll. (¢) Type HWI—Involving vermillion, white roll, and philtrum    Fig. 77.4 (a-c) Clinical subclassification of Tessier no. 0. (a) Type  IV—Involving vermillion, white roll, philtrum, columella. (b) Type  V—lInvolving columella and tip, supratip, and dorsum of the nose.    Millard [39] classified a middle split of the lip as any  vertical cleft through the focal point of the upper lip, pay-  ing little heed to the degree (Fig. 77.3a—c). Middle clefts  have been isolated into two gatherings by Millard and  Williams [39]. The principal bunching includes agenesis  of the frontonasal procedure, and the second gathering is  portrayed as separated to the middle component. The last  is related with different degrees of nasal bifurcation and  cranial malformations including hypertelorism [40-42]  (Fig. 77.4a-c).   The number 1 cleft is also called as a paramedian cleft.  Skeletally it passes through the frontal bone affecting the  olfactory groove along the ethmoid producing hypertelorism    (cl, c2) Type VI—Involving columella, tips, supratip, dorsum of the  nose and frontonasal area    (Fig. 77.5). It also widens the area between the nasal bone  and the frontal process of maxilla. The soft tissue component  involves the dome of the nose and may involve the alveolus  and the lip. It may have a cranial counterpart in No 13 cleft.  [33]    1. Alar clefting that produces deviation of the nose to the  opposite   4. Tongue-shaped frontal hairline which is indicative of no.  13 cleft [35]    1. Clefting of the maxilla extending posteriorly as a total  cleft of the hard palate.   4. Asymmetry of the pterygoid plates and increased promi-  nence of the lesser wing of the sphenoid bone.    77.5.1.3 Number 2 Cleft  Tessier no. 2 clefts are found parallel to the midline Tessier  No. 0 clefts [33]. The deformation of the middle third of the  nostril rim is a characteristic feature of the Tessier 2 cleft.  This produces widening of the nasal bridge and flattening of  the lateral side of the nose (Fig. 77.6a—e).    1. Alveolar dysplasia from the lateral incisor to the pyriform  aperture.   4. A bony indentation is seen near the naso-maxillary suture  [35].   5. Dysplasia of the lateral ethmoid region with orbital hyper-  telorism [43].   No. 3 is the oculo-nasal cleft (Morian I). This is also called  “medial” orbito-maxillary cleft which passes through the  lacrimal segment of the lower eyelid. This paranasal cleft  occurs obliquely involving the lacrimal groove [33]. The  patient may have microphthalmia [35] but anophthalmia is  rare [45] (Figs. 77.7a—c and 77.8a-c).    Soft Tissue Characteristics [35, 46]  The important soft tissue features of the Tessier 3 cleft  are:    1. Soft tissue hypoplasia of the face in the vertical direction  [35]   4. Displacement of the medial canthal apparatus and the lac-  rimal punctum of the lower eyelid    1. Absence of the frontal process of the maxilla and medial  wall of the maxillary sinus [33]   4. Continuity of the nasal cavity into the maxilla with no  bony lateral nasal wall [35]   6. Narrowing of the ethmoid body and sinus on the affected  side [35]    77.5.1.5 Number 4 Cleft  The No 4 Tessier cleft is a rare, complex, and gruesome  craniofacial malformation [47]. No. 4 is the oculofacial  separated I (Morian II). This is a “focal” orbito-maxillary  cleft [33].   It may range from a unilateral notch paramedially to large  bilateral tissue defects extending from the mouth to the eyes  with huge bony fissures [47] (Fig. 77.9a-f).    . Clefting extending halfway between the philtral crest and  the labial commissure   . Extreme degree of vertical tissue deficiency extending  from the labial cleft to the ocular separation in the lower  eyelid [35]   . Microphthalmia with exposure keratitis secondary to eye-  lid deficiency [47]    and the canine proceeding cephalically medial to the  infra-orbital foramen onto the orbital floor.    . This may be associated with a cranial cleft no 12.    77.5.1.6 Number 5 Cleft  The Tessier No 5 cleft is a very uncommon malformation  and is also referred as the oculofacial cleft If (Morian IID.  This lateral orbito-maxillary cleft gets through the medial  third of the lower eyelid [33] (Fig. 77.10a, b).    1. Clefting immediately medial to the commissure which  courses along the cheek lateral to the ala of the nose, end-  ing in the lateral half of the lower eyelid.    . The globes are usually normal but may occasionally show  microphthalmia [35].    . The alveolar cleft starts lateral to and travels lateral to the    infra-orbital foramen and ends in the lateral part of the  orbital floor. There may be associated hypoplasia of the  maxillary sinus [48].    Fig. 77.8 (a-—c) Tessier 3. (a)  With bilateral involvement (b)  without ocular involvement  (c) with oral involvement    contents. This is otherwise called as zygomaticomaxillary cleft which  3. Thickened lateral orbital wall and abnormal greater wing may form an incomplete variant of the Treacher Collins syn-  of the sphenoid bone. drome (Fig. 77.11a, b). It was named as maxillozygomatic    4. Cranial base may be generally normal [35]. dysplasia by Van der Meulen [33, 49].    Soft tissue involvement of the No 6 cleft is detailed below:    . Vertical cleft furrow extending from the oral commissure  to the lateral aspect of the lower eyelid.   . This also involves the zygomatic eminence pulling the  lateral aspect of the palpebral fissure down with inferior  displacement of the lateral canthus [33].   . This gives the appearance of an anti-mongoloid slant and  lower lid ectropion.   . Colobomas may be seen in the lateral lower eyelid region  [33].    Fig. 77.9 (a-f) Tessier 4. (a, b) Skeletal Tessier 4. (c, d) Unilateral Tessier 4. (e, f) Bilateral Tessier 4   . The cleft enters the orbit at the lateral orbital floor.    Fig. 77.11 (a, b) Tessier 6. Skeletal Tessier 6. (a) Unilateral Tessier 6. (b) Bilateral Tessier 6    77.5.1.8 Number 7 Cleft 4. There may be absence of the parotid gland and duct.   This is a temporo-zygomatic cleft and is the most well- 5. There may be external and middle ear abnormalities   known of all the craniofacial clefts [35] (Figs. 77.12 and [50-52].   77.13a—d). It may occur along with hemifacial microsomia. 6. Abnormal pre-auricular hair form in hemifacial microso-  Soft tissue features include: mia and Treacher Collins disorder [35].    1. Soft tissue clefting from the oral commissure to the pre- Skeletal qualities include [35, 53, 54]:  auricular hairline.  2. It may range from a mild broadening of the oral commis- 1. Skeletal cleft involves the — pterygo-maxillary    sure with pre-auricular skin tags to a complete fissure junction.  ending in a microtic ear [35]. 2. Hypoplasia of the posterior maxilla, mandibular  3. There may be deficiency of the ipsilateral tongue, soft ramus, coronoid, and condylar process with occlusal    Fig. 77.13 (a—d) Subclassification of Tessier 7. (a) Oro-aural Tessier 7. (b) Bilateral Tessier 7. (c) Tessier 7 with cleft lip. (d) Tessier with ear tag    3. Hypoplasia of the zygoma with displacement and defor- 77.5.1.9 Number 8 Cleft (Fig. 77.2)  mation. In extreme cases the arch may manifest as a little This fronto-zygomatic cleft situated at the lateral canthus  stump alone. forms the equator of the Tessier craniofacial cleft sphere. It is  4. There may be true orbital dystopia in severe cases. a part of the zygomatico-frontal dysplasias [49]. The number  5. There may be a tilt of the cranial base [35]. 8 cleft seldom occurs in isolation and usually occurs as a part    of other craniofacial clefts. It corresponds to the cranial  occurrence of the No 6 cleft. In bilateral occurrences it is  associated with numbers 6 and 7. This shows features similar  to the Treacher-Collins and the Goldenhar’s disorder with  the former showing more skeletal deformities and the latter  soft tissue ones [55].    1. Cleft extends from the lateral canthus to the temporal  region.   2. They may present with dermatoceles and colobomas with  absence of the lateral canthal apparatus.   3. Abnormal hair patterns may be present between the tem-  poral area and the lateral canthus.   2. Features of the Goldenhar’s or Treacher-Collins syn-  dromes may be seen with the zygoma being hypoplastic  or missing along with the lateral orbital wall [59].   3. The palpebral fissure shows a lateral descent due to the  absence of the zygoma.    77.5.1.10 Number 9 Cleft  No. 9 is a form of the upper “lateral” orbital cleft. The cleft-  ing is seen in the lateral third of the upper eyelid and the  lateral supra-orbital angle (Fig. 77.14). It is the cranial exten-  sion of the number 5 facial cleft [52]. There may be a defi-  cient greater sphenoid wing in this type [60].    1. Anomalies of the lateral third of the upper eyelid and the  eyebrow.   4. The superolateral bony deficiency in the orbit may be the  cause of lateral displacement of the globes.   5. Anterior displacement of the temporal hairline with tem-  poral projection.   6. Palsy of the 7th cranial nerve with temporal and eyelid  signs may be common.   2. The greater wing of the sphenoid may be distorted affect-  ing morphology of the orbital wall.    3. Hypoplasia of the pterygoid plates.  4. Decrease in the antero-posterior dimensions of the ante-  rior cranial fossa [35].   the supra-orbital edge, lateral to the supra-orbital nerve  (Fig. 77.15a, b) [33]. This is the cranial counterpart of the No  4 cleft. Both present with similar ocular deformities and may  show colobomata of the iris [33].   This cleft causes a large defect in the frontal bone [46].   3. Eyebrow which is deficient medially and is more dis-  persed laterally [46]   4. Occurrence of frontal encephalocele involving the middle  third of the frontal bone and the orbital roof [35]    1. Cleft defect on the lateral aspect of the supra-orbital rim  which may involve an encephalocele.   3. Orbital hypertelorism may be a feature in severe cases  with distortion of the anterior cranial base [35].    77.5.1.12 Number 11 Cleft (Fig. 77.2)  No. 11 is the upper “medial” orbital cleft. This shows colo-  boma of the medial third of the upper eyelid, with stretching  of the eyebrow [33]. This cleft is often associated with the  facial cleft No 3 [35]. Van der Meulen incorporated this  deformity in his frontal dysplasia group [49].   2. Disturbance in the upper eyebrow with a tilt toward the  frontal hairline    1. Frontal bone defect medial to the supra-orbital nerve and  lateral to the ethmoid and lacrimal bones   4. Deficiency of the lacrimal bone with associated lacrimal  stenosis [46]    77.5.1.13 Number 12 Cleft  The No 12 cleft shows deficiencies in the ethmoid labyrinth  and the glabella [46]. This cleft is usually found medial to  the medial canthus [35] (Fig. 77.16).    1. Soft tissue dehiscence medial to the medial canthal appa-  ratus [33]   2. Lateral displacement of the medial canthus with aplasia  of the medial eyebrow    3. Presence of a V-shaped frontal hairline in the paramedial  region of the forehead [35]   It is situated between the nasal bone and the frontal pro-  cess of the maxilla passing through the frontal bones and  along the olfactory groove [36] (Fig. 77.17).    1. This occurs medial to the eyebrow which remains undi-  vided [36].    of the nasal skin and alar skin and results in an alar carti-  @©Association of Oral and Maxillofacial Surgeons of India lage cleft [46].    1. Deformities of the medial aspect of the cribriform plate  [46].   2. There may be olfactory groove widening with associated  widening of the cribriform plate and the ethmoid sinus  with resultant hypertelorism.   3. Paramedian frontal encephalocele may cause inferior dis-  placement of the cribriform plate with orbital dystopia.   4. Unilateral and bilateral types of the number 13 cleft exist  with bilateral demonstrating the most extreme forms of  hypertelorism [4].   No. 14 is the cranial congener of the cleft no. 0, which is the   3. The periorbita including the eyelids and eyebrows is gen-  erally normal.    Fig. 77.18 (a—g) Tessier number 14 with variable degree of nasal duplication and hypertelorism    4. Midline projection of the frontal hairline [35].  5. There is distortion of the nasal capsule and the developing  forebrain stays in a lower position.   2. Frontal encephalocele may be seen herniating through the  midline frontal bone defect.   3. Caudal flattening of the frontal bone is flattened with flat-  tened glabellar region   5. The crista galli and the perpendicular plate of the ethmoid  are bifid, and there is an expanded separation between the  olfactory grooves [35].   6. The crista galli and ethmoids are widened with caudal  dislodgement.   7. There may be a shortening of the middle cranial fossa.   8. The anterior cranial fossa is tilted upward, producing a  harlequin eye disfigurement on plain radiographs [35].    77.5.1.16 Number 30 Cleft  Tessier 30 cleft otherwise known as lower midline facial  cleft or median mandibular cleft is a rarity (Fig. 77.19).  Median cleft of the lower jaw was first described in 1819 by  Couronne [30].   It is generally constrained to a deformity in the soft tissue  of the lower lip.   In its severe form, it may groove or split the mandibular  symphysis and at times involve the midline structures of the    neck including the hyoid bone, the thyroid, and even the  strap muscles. The anterior part of the tongue may be bifid,  showing ankyloglossia [54], with one case of absence of  tongue being reported [55].    Surgery for facial deformities involves the best balance of art  and science. The restoration of the malformed anatomy  requires artistic creativity, while the science lies in the rees-  tablishment of impaired function [57].   From a careful perspective, even microform clefts might  deform. Contingent upon the level of distortion, an arranged  strategy has been viewed as the treatment of choice [58]. Due  to their multifaceted nature; the individual level of cleft  involves successful reconstruction and the rehabilitation in  practically every one of the cases request multistep and  multi-proficient procedure [59]. Besides cautious examina-  tion, imaging methods are important to evaluate the individ-  ual level of skeletal inclusion. For correct determination  current imaging frameworks seen in systems, for example,  CT, MRI, and 3D CT, permit better preoperative comprehen-  sion of the issue and planning of the surgeries. Analysis  ought to be founded on a classification relying upon the site  and types of defects (morphology) which helps in foundation  of a legitimate treatment plan [60] (Figs. 77.20, 77.21, and  77.22a-e).   Institutionalized treatment plans are not constantly con-  ceivable in light of the assortment of craniofacial clefts and  dimensions of seriousness. Be that as it may, core values are  useful in deciding the best possible planning and stages for  restorative surgery [30]. The Australian Craniofacial Unit  Treatment Protocol, which is a pioneering center with inter-  national acclaim, has recommended the following:    e Early repair of the soft tissue defects and preventing  exposure keratitis   ¢ Orthodontic intervention interceptive orthodontics and  speech therapy for the school-going years (4-10 years)   ¢ Reconstruction of the orbital floor, orthognathic surgery,  and rhinoplasty to be done after growth completion [30]    Literature reveals that the midline Tessier 0 and 14 clefts are  among the most common encountered [5], while the  combination of 0 and 14 is the most common combination of  non-isolated clefts [61].    The most commonly adapted protocol for Tessier no.  0-14 is modified from surgical protocol for midline Tessier  0-14 craniofacial clefts (David 2006) (Fig. 77.23).    (i) The medial orbital zone  (ii) The zone of the maxilla, oral cavity, and lips  (iii) The zone of the nose    Treatment is generally formulated based on the degree of  involvement of these zones (Figs. 77.20 and 77.21).    77.6.2.1 Resection of Encephalocele  An encephalocele is a herniation of a part of the cerebral  matter through a deformity in the skull. This may contain  meninges (meningocele), or meninges, cerebrum, and ven-  tricle (meningoencephalocystocele) [61].   Tessier no. OQ—14 is most generally connected with fronto-  ethmoidal gathering of encephaloceles group which can be  subdivided into nasofrontal, nasoethmoidal, and nasoorbital    1. Meticulous repair of skin deformities. This helps prevent  contamination and desiccation of brain tissue.    2. Water-tight dural repair with removal or invagination of  the non-functional brain tissue which is present  extra-cranially.   3. Complete craniofacial reconstruction of skeletal compo-  nents. Care taken to prevent appearance of a long nose [62].    Hypertelorism is the most common indication for major cra-  niofacial correction in a Tessier 0-14. Treatment strategies  are varied and range from medialization of the medial wall of  the orbits to total repositioning of the orbital and facial bipar-  tition [63]. Hypertelorism is a physical finding in many cra-  niofacial malformations, which is characterized by an  increase in interorbital distance. It may be a part of a syn-  drome but it is not a syndrome by itself.   In 1924, Greig called orbital hypertelorism as “ox-eyed”  and also coined the term “ocular hypertelorism” [64]. The  more accurate term of “orbital hypertelorism” to denote  true lateralization of the orbital complex was coined by  Tessier in 1972 [65]. Tessier classified hypertelorism into  three degrees based on the interorbital distance [65, 66]  (Fig. 77.24).    77.6.3.1 En Bloc Osteotomies (Fig. 77.25a—d)  Radical mobilization of the orbits to correct increased inter-  orbital distance is one of the most challenging procedures in  craniofacial surgery [67].   Paul Tessier was the first to perform orbital mobiliza-  tion using a trans-cranial approach [53]. This surgical  intervention was planned to eliminate undue risk to the    Adapted Surgical Protocol for Midline 0-14 Tessjer Craniofacial Clefts (David, 2006) [16, 17]    e Preserve the essential functions of the airway, feeding, sight, and; hearing   e Possible use of tissue expanders beneath the zygomatic periosteum in extreme hypertelorism  e Temporary nasad reconstruction, as this will not be repeated later    e Orthodontic management is commenced when enough permanent teeth are present  e Alveolar bone grafting is carried out to correcti the more extensive defects in the maxilla that may to present    10 years until the completion of growth  e Maintenance of the orthodonitic therapy with retainers  e Further preservation of the eyes and hearing if required   e Midface surgery performed at any level, with or without bone grafting/mandibuloar surgery depending on need  e After establishment of the facial platform, platform, definitive nasal reconstruction is performed    HYPERTELORISM  Degree Interorbital distance (mm)  I. Slight 30 to 34  Il. Moderate 35 to 39  lll. Severe 40 +    optic nerve [65]. Converse described in 1968 preservation  of the olfactory nerves by performing subcranial U-shaped  osteotomy [68]. Schmid described the extra-cranial cir-  cumferential orbital osteotomies for medializing the  orbits [68], while Jacques van der Meulen described the  facial bipartition in 1983 [69]. Medialization of the medial  orbital walls and hemifacial rotation do not interrupt mid-  facial growth and thus were performed before age 5 in the  majority of patients. Orbital translocation causes growth  disturbances and thus is to be performed after attaining  skeletal maturity [63].   The facial bipartition procedure involves the mobilization  and rotation of the entire midface in a monobloc fashion  (Fig. 77.27a, b). The osteotomy involves the supra-orbital  rims first. It is then continued along the lateral orbital walls  in a similar fashion to the LeFort 3 osteotomy and is dropped  caudally to involve the dentate segment also in the mobilized  segment. The intra-orbital circumferential osteotomies are  performed using a combined trans-cranial and trans-facial  approach once the hemifacial segments are mobilized, the  intervening ethmoids are resected creating space for the  upper face to be rotated medially. This causes the maxillary  dentate segment and the palate to have a lateral rotation  increasing the transverse dimension of the face and correct-    ing the palatal crossbite of the upper posterior teeth. This  procedure can also be combined with an advancement of the  midface complex by combining it with a LeFort 3 type modi-  fication [72].   Correction of orbital hypertelorism done using a box oste-  otomy may include corrections of associated nasal deformi-  ties. Bone and cartilage grafts may be necessary to provide  nasal framework. Skin grafts may be required for nasal cov-  erage and may be accomplished by local flaps. The box  osteotomy is generally preferred when the dental occlusion  is normal.   Van den Elzen et al. (2011) advocated waiting until after  age 10 (after eruption of permanent dentition) to perform  orbital box osteotomy. Monasterio and Taylor [61] supported  the use of orbital translocation after skeletal maturity and  have stated that early intervention retards midfacial growth.  Tessier (1973) noted that neuro-ophthalmological benefit  was increased by correcting hypertelorism at 3 years and  psychosocial benefit was heightened by operating at 6 years,  before schooling begins, or after 12 years to preserve the  dentition. Marchac et al. (1999) also described the use of box  osteotomies after 12 years of age.   The spectacle osteotomy is done by performing the trans-  frontal craniotomy and preservation of frontal bandeau along  with trimming of the bone in the periorbital region and  around the pyriform aperture with medialization of the  orbits.   A lateral canthopexy is an integral part of this procedure  [48]. The medial canthi should be recognized and anchored  using trans-nasal wires. At times this is performed with a mini-  plate anchor for orienting the wires in the right direction [72].  The plate is secured to the thick nasal bone, and the lower hole  is kept at the level of the lacrimal crest. The canthi are inde-  pendently fixed to these holes bilaterally utilizing steel wires  (Also refer Chap. 79 on craniofacial syndromes) [73].    The midline cleft lip notch can be successfully treated  by holding fast to three noteworthy standards  (Fig. 77.30a, b):   2. Approximation of the split orbicularis oris muscle  at the midline    Fig. 77.28 (a-d) Box osteotomy—skin incision for the intracranial block bone removed near pyriform area, calvarial bone graft, miniplate  correction of the orbital hypertelorism consists of bicoronal incision, fixation and closure  transfrontal craniotomy sparing the frontal bar, periorbital osteotomy,    Fig. 77.31 (a, b) Resection of the excess skin of the nasal dorsum and closing in the midline    In managing the 0-14 cleft, the clinician should be able to  diagnose if it is a true or a pseudo occurrence. In cases of a  true midline cleft, care should be taken to reconstitute the  important components of the lip, external nose, and nasal  septum. Resection of excess skin also needs to be planned  and performed [36] (Figs. 77.31a, b and 77.32a, b).   Nasal clefts include Tessier no. 2 and Tessier no. 3 clefts.  Principles of surgical management (Fig. 77.33). Because   of their rarity and extreme variability, it is not surprising that    Fig. 77.32 (a, b) Reconstruction of the lip and resection of the excess skin of the nasal dorsum and closing in the midline    must be approached on an individual basis using the basic  principles of nasal reconstruction as a foundation.   The fundamental principles and techniques of nasal  reconstruction are to assess what is present, what is missing,  utilization of available tissue, and importing required tissue  as indicated by the deformity.   Each component of the nose, skin, lining, and support (bony  and cartilaginous), must be evaluated in a quantitative and  qualitative manner. The quality and quantity of external skin  and nasal lining are evaluated for deficiency or excess. The  integrity of the cartilaginous framework, nasal septum, has  to be assessed.   Patients with complex craniofacial clefts frequently require  multiple staged reconstructive procedures. Planning of these  procedures must be tailor-made to each patient. Surgical  stages must be planned and executed with all subsequent sur-  gical sessions clearly in mind.    Replace Like with Like  Whenever possible absent or deformed tissue should be  replaced with identical or similar autogenous material.  Bony defects may be present along the cleft from the  alveolus to the orbit. It is essential to reestablish a stable ana-  tomic bony base to ensure adequate support for the soft tis-  sue reconstruction of the nose and orbit. Autogenous split  calvarial, rib, and iliac graft are the general preferences.   Free cartilage grafts alone may often suffice to correct small  deficiencies of the alar rim, nasal rim, nasal dorsum, or tip.  Larger defects of the upper and lower lateral cartilages can  be replaced using conchal or septal cartilage grafts. Thin  bone from the perpendicular plate of the ethmoid can be used  to replace upper lateral cartilage.    Small composite chondro-cutaneous grafts from the  concha can be used to replace small defects if additional  lining is needed. For larger cartilage defects in the area of  the upper laterals, septal hinge flaps can be used.  Reconstruction of lower lateral cartilage can be accom-  plished using conchal cartilages or chondromucosal grafts  from nasal septum.   Adequate lining to the nose is critical to achieve a functional  and predictable aesthetic result. This is also essential to rees-  tablish vascularity to the underlying tissue and to minimize  contracture of the soft tissues. Local turnover flaps are useful  for small defects, while larger defects may require vascular-  ized tissue transfer.    Skin  Small nasal clefts are amenable with local tissue transfer in  the form of rotation flaps from the lateral nasal area. Onus in  simple nasal clefts is given to the reestablishment of the alar  rim contour [68]. The use of z-plasty techniques and com-  posite grafts helps in achieving additional symmetry [77].  Downward rotation of the cephalically displaced alar rim  is the first step in this process. This may require the use of a  back cut to rotate the alar margin caudally. The triangular  defect produced by the alar rotation is then filled by a trans-  position flap from adjacent areas having excess skin [78, 79].  Descriptions of a nasal dorsal rotation flap  (Figs. 77.34a—d and 77.35a, b) for a Tessier 2 cleft and a  brow-eyelid-nasal transposition flap for a Tessier 3 are pre-  dictable techniques [80].    The nasal dorsum rotational flap design to correct Tessier  no. 2 clefts improves alar symmetry at the cost of reduced  nostril size. A notch on the affected ala is a major problem to  handle in this technique [80, 81].   The forehead-eyelid-nasal transposition flap  (Fig. 77.36) technique involves the use of an inter-eye-  brow-forehead flap which is pedicled on the tissue of the  nasal bridge. The rotation achieved by the flap gives both  the alar and nostril symmetry while reducing the need for  revision [80].   Optimal reconstruction of the nose should be based on the  principle of aesthetic subunits as described by Gonzalez-  Ulloa and Castillo (1954) and refined by Burget and Menick    (1985). Superior results are better achieved by replacing the  entire subunit of the nose rather than simply patching the  defect. The achievement of the nasal proportions should be  in conjunction with facial proportions though there are many  aesthetic and surgical limitations because of associated  severe craniofacial deformities. Definitive nasal reconstruc-  tion may need to be delayed or staged as explained, until  optimal canthal, orbital, and maxillary relationships are  obtained.    Tessier no. 4 cleft is a rare, complex malformation which has  severe implications on both the soft tissue and skeletal struc-  tures of the face. As a general rule, priority needs to be given  for reconstructing the soft tissue envelop, and the skeletal  repair should in the form of osteotomies or bone grafting  procedures need to be deferred until the school-going years.  This is due to the fact that early intervention to the bony skel-  eton may hinder the development of the midface and associ-  ated (Resnick and Kawamoto 1990; Kawamoto and Patel  1998) [76].   An important clinical indication that necessitates emer-  gency intervention is exposure keratitis of the cornea and  resultant blindness. This depends on the gravity of the cleft  deformity. In narrow cases of Tessier 4 cleft, the clefting is  more toward the medial side of the orbit which retains a large  bony component of the lateral orbit. This lends support to the  globe and enables reasonable competence of the upper eyelid  to cover the cornea. In such instances the early surgical  intervention may be avoided [82]. On the other hand in  severe cases, there is total absence of the orbital floor causing  the globe to sink downward with the cornea facing upward  due to a lax supporting structure. This prevents the upper    Fig. 77.37 (a) Incision for bilateral Tessier no. 4 (b) unilateral tessier 4 on left side with tessier 7 on right side    eyelid from being able to protect the cornea, with the resul-  tant problem of exposure keratitis and permanent corneal  damage. Such instances produce an emergency, and a repair  of the orbital support system is mandated. In cases where an  early intervention is not possible due to medical and anes-  thetic implications, emergency intervention at least in the  form of a tarsorrhaphy is performed within 2-4 days of birth.   While treating severe deformities like the Tessier no. 3  and Tessier no. 4 clefts, a “split method” of management can  be utilized to handle the anatomical regions individually as  given below [83].    77.6.4.1 Managing the Lid Segment  An ectropion like deformity is commonly present. This can be  managed using conventional techniques. They include (a) a  back-cut release of the lower eyelid to cheek junction and  medial advancement of the lower eyelid with medial cantho-  pexy, (b) lower lid resection with inferior layered tarsal strip,  or augmentation of the tarsal plate with spacer grafts. However  in cases where there is inadequate tissue locally, tissue must be  imported into the lower eyelid for optimal results [83]. Some  of the commonly used flaps for this include the median fore-  head flap and the nasolabial flap. However, free vascularized  tissue transfer techniques also may be adopted [84].  Numerous techniques have been described for the man-  agement of the Tessier 4 cleft. But most of them result due to  the interdigitating scars produce a sub-optimal outcome [33]  (Tessier 1976; Kawamoto 1990). Longaker et al. (1997) pro-  posed the superiorly based nasolabial flap that was trans-  posed to the lower eyelid. Though this technique had an  advantage cosmetically, it had that limitation that it was use-  ful only for mild forms of the cleft. The cheek advancement  technique described by Van der Meulen [4] had the advan-  tages of being useful even for wider clefts and favorable  scars along aesthetic facial subunits. Van der Meulen like-  wise depicted that it was significant for improving the scar-  ring caused by anchoring the cheek flap firmly to the pyriform  aperture [85]. However, despite the options available, it is  better to understand that a single flap may be insufficient at  times to reconstruct the eyelid [86]. To overcome these chal-  lenges, the use of tissue expanders and free vascularized  transfers have also been advocated [87, 88].    The Veau III method of bilateral lip repair can be used for  correcting the lip component. The last area to be addressed is  the naso-malar junction [89].    The primary outcomes that are needed for the correc-  tion of these clefts include:   e Skeletal continuity restoration (this includes the  orbital floor) using bone grafts    The principles to be borne in mind in the management of the  Tessier 5—9 spectrum have been modified by different sur-  geons: Tessier (1971) advocated early correction of orbital  dystopia — prior to | year of age. In all forms of facial clefts  that affect the ocular region, priority is given to the preserva-  tion of vision by early interventions to prevent exposure  keratitis of the cornea. Pre-surgical care includes use of oph-  thalmic ointments or temporary tarsorrhaphy procedures  [48, 89]. Kara and Ocsel (2001) have reported the use of  multiple z-plasties for the soft tissue reconstruction as early  as 8th day after birth.    Lateral facial cleft or Tessier no. 7 cleft is generally unilat-  eral in presentation, though may also occur bilaterally. The  bilateral form produces more gross clinical appearance with  the face being amphibious in nature with an expanded mouth  and infero-laterally placed commissures.   The condition is often related to syndromes of the  first and second branchial arches. The cleft involves the  skin, mucosa, and muscles of the oral sphincter (i.e., the  orbicularis oris and the buccinator) [89]. In rare instances  the cleft may involve the masseter [90]. This is a  condition which may be concurrent with a lot of other  deformities mandating a very thorough investigation in  any patient exhibiting the classical feature of macrosto-  mia [89].    The surgical objectives for the management of the lat-  eral facial cleft have been detailed as follows [90]  (Fig. 77.39a—d):    1. Reconstituting the oral sphincter by reconstructing  the orbicularis oris and the buccinator   2. Identification and reattachment of the other muscles  of facial expression and the masseter in cases   5. Closure of the defect in layers with the mucosa,  muscle, subcutaneous layer and skin [91]    Numerous procedures for the repair of macrostomia have  been described in literature; [16, 17, 92, 93, 96, 97] Onizuka  1965; Boo-Chai 1969; Mansfield and Herbert 1972; Skoog  1974; Talukder 1980; Kaplan 1981; Bauer et al. 1982;  Fukuda and Takeda 1985; Verheyden 1988; Yoshimura et al.  1992; Torkut and Coskunfirat 1997; Ono and Tateshita 1999,   Maximal care is exercised on the repair of the involved  muscles with an overlapping technique [94, 95]. In severe    cases other muscles of facial expression like the buccinator  and the risorius also need to be repaired (Ono and Tateshita)  [93]. This ensures normalization of both form and function  of the perioral region [94].   The skin repair consists of two parts: repair of the cheek  wall and commissuroplasty. Commissuroplasty denotes the  reconstruction of the skin mucosa junction at the corner of  the lips. Care is taken to design the repair in such a way that  there is no associated contracture in the post-surgical period.  There are various descriptions for the commissural repair.  The triangular flap repair of Ono and Tateshita [93]. This  procedure produced better aesthetics due to the triangular  design of the flaps. Kawai et al. in 1998 described an inferi-  orly based triangular flap taken close to the lower lip to mini-  mize the re-expansion of the commissure in the long term.   Eguchi et al. used the vermillion square flap method for  commissuroplasty [96].   Other popular techniques described for the skin repair of  the lateral lip element include to direct linear suturing,  Z-plasty [94], and W-plasty [96]. The purpose of a Z-plasty  is to break the long linear scar. But it is seen that the use of  multiple Z-plasty or W-plasty procedures violates the relaxed  skin tension lines. Therefore, a single Z-plasty with vertical  limb lying in the nasolabial crease is preferred [90].    77.6.6.1 Bone Grafts  The establishment of normal contour of the soft tissues is  never complete without the much needed skeletal support  system. The skeletal reconstruction of craniofacial clefts  essentially needs the use of bone grafts to fill and bridge  both minor and major defects. The consolidation and take of  the bone graft in the recipient site happens in two important  steps: (i) the bony union of the joints between the grafted  bone and the native bone and (ii) graft remodeling and  creeping substitution [97]. Bone grafting can be performed  at any age and is generally combined with soft tissue recon-  struction [97].   Repairs performed in the early years of life can be accom-  plished with bone stock from the rib or iliac crest. However,    Fig. 77.39 (a-—d) Tessier no. 7. (a) Diagram demonstrating abnormal oral aperture with distorted anatomy of orbicularis oris. (b1, b2) Clinical  presentation of patient with macrostomia. (c) Incision marking. (d) Angle grafting    the quality of the bone supplied by the ilium is better suited  for this work. The cortico-cancellous graft material can be  placed as such or carried over titanium cribs. It is important  to note that the general consensus for the use of non-  vascularized grafts is for defects less than 6 cm [98].    ¢ Iliac crest grafts are the most favored with a good stock of  available cortico-cancellous bone. Generally the anterior  iliac crest is preferred as the posterior iliac crest requires  a change of position to prone and may not accommodate  simultaneous work from two teams. Donor site morbidity  rate for anterior iliac crest grafts is around 23% and much  less for posterior iliac crest. Complications include post-  operative pain, iliac or acetabular fractures or instability,    persistent hematoma, herniation of abdominal contents,  vascular injury, lateral femoral cutaneous nerve injury,  and contour defects along the iliac crest [17].  Occasionally the use of alloplastic materials like Medpor  may also be used (Fig. 77.40).   Calvarial bone is another preferred site and can be freely  available when the surgery involves cranial procedures  and trans-cranial approaches. It has the lowest rate of  resorption among all the bone grafts making it a preferred  choice for facial and orbital reconstruction (Fig. 77.41a,  b). The parietal calvarium can safely provide up to  8 x 10 cm of the bone for harvesting [99]. The temporo-  parietal region provides more curved bone suitable for  orbital or malar reconstruction. Generally the grafting is  performed in strips so that there are no gross fractures and  later the strips are joined together to reconstruct larger  defects. Calvarium is harvested in three main forms:  partial-thickness outer cortex, full-thickness outer cortex,  and bicortical grafts. Partial-thickness outer cortex grafts  are ideally harvested from children between 4 and 8 years  of age, using an osteotome to produce a curling sheet of  the bone.   Calvarial grafts are safe in adults and are the standard  indication when simultaneous craniotomy is performed.  A bicortical graft is harvested and the graft is split. The  inner cortex is used for reconstruction, while the outer  cortex is replaced to fill the donor site defect and  contour.   Complications of calvarial grafting include contour  defects of the donor site, graft fractures, and rarely dural  tears while harvesting bicortical grafts. Dural tears man-  date a thorough and formal dural repair to prevent further  complications. Intra-cranial hemorrhage is a very rare  complication during this procedure but has been docu-  mented [100].    ¢ Grafts of ample volume can also be harvested from the    anterior tibia both in the form of cancellous bone or in the  form of cortical strip from the anterior tibial plateau.   Rib bone or costochondral grafts can be harvested from  ribs 5 to 7 which may be used as full-thickness or split rib  grafts. Costochondral grafts are extensively used in the  reconstruction of ascending mandibular ramus and con-  dylar defects. Site-specific complications include postop-  erative pain, injury to the pleura with associated  pneumothorax, hemothorax, or pneumohemothorax.  Occasionally it may cause exaggerated facial asymmetry  due to overgrowth.    Defects which are larger and demand more complex  reconstruction may not be amenable to bone grafting  alone and may require well-designed osteotomy tech-  niques [82, 101] or at times, even distraction osteogenesis  (introduced by McCarthy and co-workers) [102] to form  better contour of the involved skeletal framework and  improve function (Refer Chap. 87 on Distraction osteo-  genesis) (Fig. 77.42).    The uncommonness of craniofacial clefts has made the accu-  mulation and complete anatomic documentation of this  extensive arrangement troublesome. Preoperative and post-  operative CT examinations with 3D reproductions will  improve the understanding of these complex deformities.  The test of managing these monstrous deformities still chal-  lenges the skill and experience of many a craniofacial sur-  geon [35].   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Fractures of the iliac crest following anterior and posterior  bone graft harvesting. Review of the literature and case presenta-  tion. Minerva Stomatol. 2003; 52(10):441-8.   Ortiz-Monasterio F, Medina O, Musolas A. Geometrical plan-  ning for the correction of hypertelorism. Plast Reconstr Surg.  1990;86:650.   McCarthy JG, Staffenberg DA, Wood RJ, Cutting CB, Grayson  BH, Thorne CH. Introduction of an intraoral bone-lengthening  device. Plast Reconstr Surg. 1994;96:978-81.    Open Access This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.  org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropri-  ate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.   The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in  a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.   Hemifacial microsomia (HFM) is a three-dimensional con-  genital deformity of the craniofacial region characterized by  abnormal and underdevelopment of the first and second pha-  ryngeal arches. Due to involvement of multiple structures,  this disorder has a broad spectrum of involvement with  diverse clinical features [1].   The highly variable phenotypes have probably led to vari-  ation in its nomenclature as well, alternatives used being cra-  niofacial microsomia (CFM), otomandibular dysostosis,  facio-auriculo-vertebral spectrum, oculo-auriculo-vertebral  spectrum, first and second branchial arch syndrome,  otomandibular-facial dysmorphogenesis, and lateral facial  dysplasia [2].   This disorder is characteristically unilateral; however,  incidence of bilateral cases is 10-15%. Although this disor-  der was described first by Carl Ferdinand von Arlt, a German  physician in 1881, “hemifacial microsomia” got its name  from Gorlin and Pindborg in the early 1960s. Converse et al.  proposed the name, craniofacial microsomia, in cases of  coexisting cranial deformities where HFM is also associated  with vertebral, cardiac, and renal defects, in a condition  called as Goldenhar syndrome. It was termed “oculoauricu-  lovertebral dysplasia” (OAVD) by Gorlin. It is also associ-  ated with epibulbar dermoids and ear deformities [2, 3].    HFM is the second most common congenital anomaly of the  face, with a male predilection and which is more common in    M. Ramanathan (54)  Department of OMFS, Meenakshi Ammal Dental College and  Hospital, MAHER University, Chennai, India    Meenakshi Cleft and Craniofacial Centre, Meenakshi Ammal  Dental College and Hospital, Chennai, India    © The Association of Oral and Maxillofacial Surgeons of India 2021    the right than the left side. The incidence of HFM ranges  between 1 in 3500 and 1 in 26,000 live births [4—7].   The cause of HFM remains largely unknown. Poswillo in  1973 reported that hematomas resulting from disruption of  embryonic arteries (stapedial artery) in utero produce abnor-  malities in the development of the structures derived from  the first and second pharyngeal arches. The extent of the  hematoma and consequent tissue damage during the first  6 weeks of gestation determines the severities of deformities.  He was able to produce the CFM phenotype in mice, thus  proving his theory. He administered teratogens to produce a  hematoma of the stapedial artery and the artery of the second  arch which resulted in regional necrosis [4] (Fig. 78.1a, b).   The second widely accepted hypothesis is a change in the  migration of neural crest cells (Fig. 78.2). Retinoic acid is  believed to influence and alter the migration and distribution  of neural crest cells, which may predispose to abnormalities  in the pharyngeal arch derivatives. The intake of retinoic acid  in humans during the early stages of pregnancy may cause  multiple disorders collectively known as “retinoic acid  embryopathies” (RAEs); these include variable defects of  the jaws and the middle and external ear [3-5]. Apart from  retinoic acid, thalidomide, primidone, ethanol and isotreti-  noin have also been studied as causative agents in HFM  through their teratogenic effects [6, 7].   More recent studies have demonstrated an association  between HFM and multiple gestations, along with other  maternal risk factors such as assisted reproduction, smoking,  maternal diabetes mellitus and vasoactive drugs. Moreover,  HFM may demonstrate autosomal dominant and recessive  Mendelian patterns in families. Positive family history  accounts for 50% occurrence of features [8].   Genetic events like duplication of the OTX2 gene (chro-  mosome 14q22.3) have also been researched upon. OTX2  encodes a transcription factor, essential for craniofacial  development and = anterior brain morphogenesis.  Heterogeneity in aetiology along with variable penetrance    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1-15-1346-6_78    Fig. 78.1 (a, b) Anatomy of a  the stapedial artery during  embryonic development    External carotid artery  @Association of Oral and Maxillofacial Surgeons of India    and expression is postulated to account for the widely vari-  able phenotypic spectrum of HFM [9, 10].    Various classifications have attempted to categorize various  features of HFM as enumerated below [11-13]:    78.1.2.1 SAT Classification  The skeletal, auricle, and soft tissue (SAT)  classification.    The SAT and the OMENS (Tables 78.1 and 78.2) clas-  sifications provide an elaborate system covering simple to  complex skeletal, soft tissue and neurological involve-  ment. On the other hand, the Kaban-Pruzansky classifica-  tion explains malformations involving the mandible,  masticatory muscles, and TMJ. Therefore, it is more use-  ful for orthodontists and maxillofacial surgeons in recon-  struction of the mandible and TMJ. Thus, this classification  has become the gold standard. It involves four classes—    $2 = condyle, ramus, sigmoid notch discernible, distorted;  mandible remarkably different in size and shape   S4 = an S3 mandible with orbital involvement, lateral and  inferior orbital rims displaced posteriorly   S5 = the $4 defects plus orbital dystopia, hypoplastic,  asymmetric, neurocranium and a flat temporal fossa   A2 = rudimentary auricle with hook at  cranial end corresponding to the helix    1772 M. Ramanathan  Table 78.2. OMENS classification  Orbit Mandible Ear Nerve (cranial nerve VII) Soft tissue  0 = Normal Type I Type I = small ear, the normal structure 0 = Normal 0 = Normal  1 = small size Type IIA Type II = severe external ear deformity with a 1 =upper branches impaired 1 = mild hypoplasia  rudimentary auricle  2 = poor position Type IIB Type III = small rudiment of external ear with no 2 = lower branches impaired 2 = moderate  pinna hypoplasia  3 = small size and Type Ill Type IV = Anotia 3 = upper and lower branches 3 = severe  poor position impaired hypoplasia   In this category, the TMJ morphology is normal with ade-  quate bulk and function of masticatory muscles. The mandi-  ble is slightly hypoplastic and retruded which may project as  a mild asymmetry with deviation of the chin to the affected  side (Fig. 78.4a, b).   In this type, the affected side TMJ is shifted anteriorly and  medially than its counterpart, but the overall morphology of  the condyle and glenoid fossa remains unchanged. The joint  is functional associated with moderate muscular hypoplasia.  The patient demonstrates moderate hypoplasia of the man-  dible with occlusal canting or open bite, and the chin is devi-  ated to the affected side.   There is moderate-to-severe involvement of the joint with  condyle and the glenoid fossa grossly hypoplastic. The joint  exhibits only rotation movement of the condyle and near-  normal function. Involvement of other facial bones and defi-  ciency of masticatory muscles are clinically evident. The  patient demonstrates severe asymmetry and occlusal canting  with or without an open bite (Fig. 78.5a, b).   There is gross facial asymmetry with severely hypoplastic or  absent muscles of mastication. There is associated severe  deformity of the skull and orbito-zygomatic complex as  well. The mandible is severely affected with a “floating man-  dible” appearance due to absence of the condyle and ramus  (Fig. 78.6a, b). These patients from birth may often present  with signs of a compromised airway due to severe degrees of  mandibular retrusion.    The diagnosis of HFM is challenging owing to its wide  phenotypic spectrum. There are no definite diagnostic crite-    ria and classifications. The condition is diagnosed based on  its clinical features of phenotype ranging from involving  the orbit or ear alone to full-blown hemifacial microsomia  under development with jaw malformations. For this rea-  son, certain classification systems have been established to  standardize the assessment in an organized manner and for-  mulate treatment plan accordingly. The areas of examina-  tion include various components of the face, i.e. external  ear, mandible, temporal bone, zygoma, orbit middle ear,  facial musculature, facial nerve supply, and other adjacent  bony and soft tissues [2, 5, 7, 14] (Fig. 78.7a—d and  Table 78.3).  78.1.3.1 Skeletal Defects   The cranial involvement is mainly limited to the squamous  part of the temporal bone. Most individuals affected with  HFM demonstrate hypoplasia of the zygomatico-maxillary  complex. These patients clinically show malar depression  with orbital dystopia. The zygomatic bone hypoplasia can  lead to alterations in the glenoid fossa.   The maxillomandibular region is primarily affected due to  abnormal development of the first and second branchial  arches. It presents as unilateral facial deformities with  reduced dimensions of facial bones in all three dimensions  (3D). This produces varying degrees of gross morphological  asymmetry of the face and compensatory changes of the con-  tralateral side. The affected side in HFM may vary in severity  and also alters the morphology of the so-called normal con-  tralateral side, resulting in gross deviation in 3D, making it a  difficult term as unaffected normal side (Figs. 78.5, 78.7,  78.8a—c and 78.9a—c).   Mandibular growth changes are the earliest manifesta-  tions of HFM and are accountable for its classical presenta-  tion of facial asymmetry. The ramus of the mandible is either  absent or short, with a medial displacement. The contour of  the entire mandibular corpus is altered with a shift of the  Genium to the affected side. Dental compensations occur for  the skeletal discrepancy, which may mask the actual severity  of the clinical condition.    Fig. 78.3 (a-d) Kaban’s modification of Pruzansky’s classification for medially, inferiorly and anteriorly displaced so as to be operationally  hemifacial microsomia (HFM). (a) Type 1, (b) Type 2A, (c) Type 2B —_ equivalent to Type III  (d) Type 3 Note that the temporomandibular joint (TMJ) in Type IIB is    Fig. 78.4 (a, b) CT scan of patient with left-sided Type 1 Kaban-Pruzansky deformity    Fig. 78.5 (a, b) CT scan of patient with right-sided Type 2B Kaban-Pruzansky deformity    Fig. 78.6 (a, b) CT scan of patient with right-sided Type 3 Kaban-Pruzansky deformity   Soft tissue deformities may involve the ear, the seventh nerve  and the muscles of facial expression and mastication.  Subcutaneous tissues of the face may also be affected to  varying degrees. Macrostomia is a common feature along  with the presence of skin tags between the tragus and the  commissure of the mouth. Lateral facial clefts (Tessiers 6, 7  and 8) may be present involving the soft tissue or hard tissue  or both. Function of the cranial nerves, essentially the sev-  enth and rarely the fifth, may be compromised [15, 16].  General soft tissue bulk of the subcutaneous fat and muscles  may exhibit deficiency (Fig. 78.7). There may also be com-  promise in the function of the soft palate.   Vestigial skin rests also called as auxiliary hillocks or skin  tags are usually present along an imaginary line connecting  the tragus of the ear to the commissure of the mouth. This is  the embryonic line of fusion between the first and second  pharyngeal arches. The tags are frequently present in varying    numbers and are associated with cartilaginous remnants,  blind sinus tracts that may form inclusion cysts if obstructed  [4-6] (Fig. 78.7).   Macrostomia occurs as a result of failure of fusion of the  maxillary and mandibular processes, leading to a cleft at the  oral commissure including the skin and the underlying orbi-  cularis oris (Fig. 78.10a, b). Sixty-one per cent of patients  with HEM exhibit macrostomia as reported by Vento and  colleagues [12].   Meurman described a classification for deformities of the  external ear which was modified by Marx [17, 18]  (Fig. 78.1 la—c):   ¢ Grade II: Atresia of the external auditory canal, with a  vertically orientated cartilaginous remnant.    Fig. 78.7 (a—d) 15-year-old male, frontal and profile view (a,b) show- _(d) shows exaggerated oral aperture with deviation of mandible to the  ing features of hemifacial microsomia such as lateral cleft and preau- _ right side on mouth opening (Also see Fig. 78.30b)  ricular skin tags. (c) demonstrates macrostomia and maloccusion while    Table 78.3 Clinical features of hemifacial microsomia and the spectrum of associated anomalies   Maxillary and mandibular asymmetry with hypoplasia on Cardiac defects (tetralogy of Fallot, ventricular septal defect, aortic coarctation,  the affected side patent ductus arteriosus)   Coloboma Dysplastic kidney, vesicoureteral reflux, or ureteropelvic junction obstruction  Zygomatic hypoplasia Vertebral anomalies    Fig. 78.8 (a—c) Radiographs lateral cephalogram (a), posteroanterior cephalogram (b) and OPG (c) showing features of asymmetry. OPG show-  ing deficient body and ramus region    a-—c) Intraoral views showing malocclusion, asymmetric anterior open bite, canting and crowding    Fig. 78.10 (a, b) (Left, profile view; right, frontal view): Adult with right-sided hemifacial macrostomia. Note the deviation on mouth opening to  the deficient right side. Also note the preauricular skin tags and epibulbar lesions    e Grade III: Absent auricle, anteriorly and inferiorly dis-  placed lobular remnant.   e Radiological assessment using temporal bone CT scans  should be used to assess the middle ear structures.   Deficits in the temporalis and the pterygo-masseteric group of  muscles may be seen in HFM. This also contributes to the  skeletal deficit seen. A hypoplastic temporalis may be associ-  ated with a hypoplastic or at times absent ramus-condyle unit  (RCU) which includes the coronoid process also; a similar    association is also evident with the presentation of the pter-  ygo-masseteric muscles and the ramus of the mandible. With  cases of increasing severity, the proximal aspect of the zygo-  matic arch may also be absent with the aponeurosis of the  hypoplastic masticatory muscles filling that space. Lateral  pterygoid muscle hypoplasia ranges from mild to complete  absence and correlates with the extent of the skeletal defect.  Hypoplasia of the muscles and deficiency of the RCU lead to  abnormalities of the TMJ and also with absence or altered  joint structures. This often leads to deviation of the mandible  to the affected side at rest and on mouth opening (Fig. 2a).    Fig. 78.11 (a) Grade | mild ear deformity, (b) Grade 2 moderate ear deformity, (c) Grade 3 severe ear deformity    Fig. 78.12 (a) Unilateral cleft lip and palate patient with right-sided hemifacial microsomia, Grade | ear deformity, right-sided muscle weakness  of orbicularis oris, buccinator and orbicularis oculi. (b) Deviated smile due to facial nerve deformity   Approximately 25% of the patients with HFM are affected  with cranial nerve deficits, resulting in features ranging  from nerve weakness to complete paralysis. The marginal  mandibular branch is the most commonly affected fol-  lowed by the frontalis muscle dysfunction. Rarely, there  may be a sensory deficit due to trigeminal nerve involve-  ment along with total involvement of the facial nerve [19]  (Fig. 78.12b).   The cause for the soft palate deviation (to the normal side)  in HFM has long been debated. It is proposed that the devi-  ation may be due to a combination of skeletal asymmetry,  neurological deficits, and hypoplastic musculature.  Literature shows that patients with HFM are predisposed to  velopharyngeal dysfunction, even in the absence of a pala-  tal cleft [20].    Considering the three-dimensional skeletal nature of the  deformity, radiological assessment is of paramount impor-  tance. Conventional methods of 2D imaging are very  helpful and still relevant in assessing the condyle anatomy  and extent of asymmetry. Orthopantomogram, posteroan-  terior cephalogram, and lateral cephalogram should be  taken for initial assessment (Fig. 78.9). With the advent of  reconstructed 3D imaging, the surgeons can now evaluate  the full extent of asymmetry including the cranial base  and glenoid fossa (Figs. 78.5, 78.6 and 78.7). Scintigraphy  or technetium scan can be done in these cases to rule out  apparent hypoplasia due to hyperplasia of one side con-  dyle (Fig. 78.13a, b).    Patient with HFM must be distinguished from those with  Goldenhar syndrome, Treacher Collins syndrome, hemi-  mandibular elongation, Parry-Romberg syndrome, juvenile  rheumatoid arthritis, Nager syndrome, traumatic postnatal  deformity, postaxial acrofacial dysostosis, muscle dysfunc-  tion, branchio-oto-renal syndrome (BOR), and maxillofa-  cial dysostosis. The following is a table of distinguishing  features of hemifacial microsomia and other entities  (Table 78.4).   The incidence of HFM with concomitant orofacial  clefting is arange between 18 and 61%, including pre-  sentations of atypical clefts and macrostomia. Fan  et al. reported cleft lip with/without cleft palate in  10% of HFM patients. Thus, cleft lip and palate may  actually be considered as a part of the HFM spectrum  [20, 21]. The laterality and severity of presentation of  cleft lip/palate correlate with the severity and side of  presentation of HFM. This shows common embryo-  logical aetiopathogenesis of HFM and orofacial cleft-  ing. However, patients with HFM often present with  velar deficiencies, leading to hypernasality and velo-  pharyngeal insufficiency. Patients with HFM have a  higher incidence of cleft maxillary hypoplasia than  non-syndromic cleft patients. The already present  abnormality in maxillary growth in HFM may further  influence the midface deficiency seen in HFM patients  with CL only.    The principles involved in the management of HFM are  described below. We have categorized them as per age and  the required intervention. Growth considerations are impor-  tant in formulating treatment plan. Various challenges and  treatment methods have been described in literature with  focus on the mandible and TMJ reconstruction (Fig. 78.14  and Table 78.5).   Due to the morphological severity of the skeletal deformi-  ties, severe functional compromise of the infant’s airway  can happen after birth. Later on, the presence of a com-  promised airway can also affect the child’s ability to swal-  low. Hence, the primary management in a neonate should  be focused on stabilization of the airway and assisted  feeding [22].   A grossly compromised airway may necessitate proce-  dures to maintain the patency of the child’s airway and  facilitate the child to thrive. These procedures are neona-  tal distraction (early distraction osteogenesis), tongue lip  adhesion, or tracheostomy [22, 23]. The neonatal distrac-  tion has fallen into disfavour due to future unpredictable    (a) SPECT scan in the case of facial asymmetry. (b) Note the active uptake on the left side. Technetium scan can be done to rule out  asymmetry due to contralateral condylar hyperplasia   Condyle and ramus are short, absence of any  other soft tissue features and normal ears.  History of trauma at birth   Mandible deviates to unaffected side. Normal  form and size of condyle, slender neck and  long ramus   Pain and morning stiffness in the affected  joint. Multi-articular nature of disease  Facial atrophy of subcutaneous fat,  associated skin, cartilage, and bone which is  often unilateral and slow progressing  Multisystem involvement in some cases.  Presence of coup de sabre    growth and possibility of tooth bud damages. Most chil-  dren presenting with HFM may require assisted feeding  using nasogastric tubes or gastrotomy for a few weeks to  months.    78.1.6.3 Management of Associated Orofacial  Clefting  The incidence of orofacial clefting occurring with HFM is  approximately 10%. The most common form of clefting apart  from cleft lip is Tessier 7 facial cleft or macrostomia (Fig.  ). The cleft is repaired at 3-6 months of age as per the  standard protocol [20]. Cleft lip and palate is more severe in  HFM and is associated with worse outcomes. There is tissue  hypoplasia and neuromuscular deficiency of pharyngeal mus-  cles in patients with HFM. This may be responsible for the  development of palatal fistulas and exacerbation of VPI, mak-  ing management of cleft palate more challenging in such  cases.  78.1.6.4 Intermediate Surgical and Orthodontic  Management  Management during the growth phase in HFM differs from  that of an adult. Intermediate surgical management includes  reconstruction of the external ear which may be planned at  6-7 years as the contralateral ear achieves its full growth dur-  ing this time. Reconstruction of the cranio-orbital region is  usually accomplished between 7 and 9 years as calvarial  growth is almost complete during this time. A split calvarial  graft to reconstruct the lateral orbital rim and zygoma is the    Fig. 78.14 Flowchart depicting algorithm of treatment at various levels according to growth    Early growth) of growth)  - Airway «Skeletal correction + Definitive skeletal  ¢ Swallowing (DO) correction (DO + OGS)  - Vision + Soft tissue correction + Soft tissue correction (fat/  - Hearing (free fat transfer) microvascular free flaps)  -Cleft lip and + Nerve deficit    graft of choice for reconstruction of deficient zygomatico-  orbital region. Surgeons have also used temporo-parietal myo-  osseous flaps for better bulk, contour and retention of graft in  place.   Orthopaedic growth modification can help these patients  to correct occlusion in early stage [23-25]. If the patient has  growth potential, with the stimulus provided by a hybrid  functional appliance and stretching the soft tissue, growth  can be increased on the affected side. The child must have at  least 20 mm mouth opening to ensure that proper translation  of condyles allows mandible growth. An asymmetric func-    tional appliance (hybrid) that guides the mandible to a new  postural position, controls the eruption of teeth and inhibits  the soft tissue pressure is used [26]. It directs the develop-  mental growth of mandible three dimensionally.   An orthodontist should constantly monitor the eruption of  primary and permanent teeth to improve mandibular  deficiency and maxillary canting. After the adolescent  growth spurt, occlusion can be achieved by means of fixed  orthodontic appliances.   Variations in the maxillomandibular complex manage-  ment range from early intervention (Figs. 78.16a, b,  78.17a, b and 78.18a, b) to late reconstruction after growth  completion. Wait-and-watch policy with only dental and  orthodontic interventions may be adopted to reduce the  impact of the deformity on the dental occlusion and mas-  ticatory function. Definitive surgical reconstruction of the  maxilla, mandible and TMJ can be taken up after cessa-  tion of growth [27-31].    Fig. 78.15 (a, b) Surgical correction of lateral facial cleft through commissuroplasty. (a) pre-operative photo showing macrostomia. (b)  post-operative photo demonstrating correction with commissure reconstruction    Fig. 78.16 (a) Preoperative radiograph-deficient left ramus and body. Note the absence of teeth and tooth buds on the left side. (b) Vertical ramus  distraction done to achieve symmetry of the mandible and chin    Fig. 78.17 (a) Intraoperative photograph of the same patient as in Fig. 78.16, showing the horizontal cut. (b) Distractor removal after 3 months  showing consolidated anatomic bone formation    Fig. 78.18 (a) Preoperative frontal photo of the same patient in Fig. 78.16 showing left-sided HFM with ipsilateral chin deviation and facial  asymmetry. (b) Postoperative view showing considerable symmetry of the face   In cases where the ramus-condyle unit (RCU) shows reason-  able function to translate into skeletal growth, growth modi-  fication with the use of functional appliances does play a role  by achieving the following outcomes:    1. To facilitate eruption of the dentition in a favour-  able pattern.   2. To prevent dentoalveolar compensatory mecha-  nisms from worsening the deformity.    The focus of functional therapy is repositioning the affected  condyle to a more inferior and anterior position to enable the  mandible to grow and catch up for the intrinsic skeletal defi-  cit [29-31].   Construction of the external ear is a priority in the aesthetic  management of HFM patients. Two important factors that  affect the ability to construct the ear are the decreased  anteroposterior dimension of the upper face and the absence    of an adequate platform (i.e. temporal bone cavity). The  position and quality of the soft tissue remnants should also  be kept in mind while planning surgery. An ear reconstruc-  tive surgeon and the maxillofacial surgeon should work  collaboratively to determine the most ideal location of the  ear relative to the future constructed ramus-condyle unit.  Reconstruction options include (1) autogenous rib carti-  lage, (2) alloplastic options such as Medpore, and (3) tis-  sue-engineered auricular framework. The technique of ear  reconstruction is dealt with in detail in Chap. 35 on “Ear  Reconstruction”.   Though autologous chondral cartilage for reconstruction  still remains the best option, it requires a multistage approach  to (1) harvest the costal cartilage grafts and create a frame-  work by carving (time-consuming and fixation and retaining  of shape challenges), (2) place the graft (positioning as per  existing altered morphology), (3) transpose the lobule (soft  tissue deficiency—tissue expander may have to be used) and  (4) create a post-auricular sulcus (with skin graft and split  temporalis graft) (Fig. 78.19a, b).   Various materials have been used for alloplastic ear recon-  struction with varied results. Porous polyethylene’s inert nature  and pore size provide and allow for some tissue ingrowth and  are safe to use. The alloplastic materials always carry a risk of  rejection and infection and may not have accurate sizes and  shapes as they are stock implants with limited sizes.    Fig. 78.19 (a) Pre- and (b) post operative photograph of ear reconstruction using rib graft (Also refer Chap. 35 on Ear reconstruction)    Tissue-engineered 3D cartilage reconstruction and its use  in regular clinical practice are under trial in many parts of the  world though long-term clinical studies still lack regarding  its application and optimal results.   Management in adults includes definitive reconstruction for  skeletal and residual soft tissue deficits. With the advent of  3D imaging and computer-assisted surgical planning and  printing, precise spatial relationship of the cranial structures  with maxillomandibular complex can be studied. This  printed models give the surgeon extra weapon outside theatre  to simulate surgery and make appropriate decisions before  going to theatre. Appropriate treatment plan can be virtually  executed, and a CAD-CAM splint can be fabricated to facili-  tate the accurate surgical outcome [32, 33] (Table 78.6).   Orthodontic preparation before definitive surgical correction  of the face is similar to the conventional pre-surgical orth-  odontic protocols. These include arch levelling and  alignments, de-crowding and transverse widening if neces-   Type I Correction of vertical dimension  Adjusting maxillomandibular relationship and  facial asymmetry   Type IIb Neocondyle reconstruction/preservation of  glenoid fossa, augmentation of RCU + type I  management    sary. Compromise may be necessary in many cases due to  the extreme lingual tilt on the affected premolar-molar areas,  leaving few options for the orthodontist due to limited bone  availability for straightening the teeth [29, 30].   Conventional orthodontic treatment may take longer  period and may necessitate the use of anchorage screws for  aligning some teeth.   In types | and 2A, the glenoid and condylar components of  TMJ are morphologically intact with minimal hypoplasia.  There is no specific indication for the reconstruction of the  TMJ since the joint exhibits normal movement characteris-  tics, and the patient is able to demonstrate adequate mouth  opening and masticatory function. Deviation while mouth  opening can be seen towards the affected side.    Teeth eruption and angle of its placement will be ham-  pered even in these two types of situations which will  require further definitive treatment. Simultaneous maxillo-  mandibular distraction introduced by Monasterio and  Molina is an alternate method for achieving maxillary and  mandibular corrections without disturbing the dental inter-  cuspation and occlusal cant [34] (Figs. a, b and    (a) Preoperative view showing right-sided maxillomandibular deficiency. (b) Postoperative view showing correction of asymmetry    Fig. 78.21 (a, b) Radiographs of the same patient as in Fig.  treated with maxillomandibular distraction (Molina’s technique). (a)    ramus-condyle unit on the right side. (b) Post-distraction xray showing  lengthening of the right ramus-condyle unit with the distractor in-situ   Type 2B patients exhibit severe hypoplasia of both the con-  dylar and the glenoid elements of the joint, thus causing  altered functioning of the joint. This greatly reduces or there  is a complete absence of the translatory movement of the  joint sparing the rotatory movement. The mandible may  completely deviates towards the affected side. The arc of  rotation completely shifted, leading to malocclusion and  scissor bites sometimes.   Distraction osteogenesis can be used to correct the defi-  ciency of the mandibular body along with reshaping the gle-  noid and condylar process. The use of osteotomies to correct  the dentofacial deformity is also performed either in the  same setting or in a staged manner.   Options for reconstruction of the ramal-condylar unit are  another concern which can be approached with costochon-  dral grafting and alloplastic joint reconstruction [35]. The  costochondral graft for stimulated growth should be used by  the age of 7 years, which can be used as an onlay graft on top  of the existing ramal segment in the correct position of gle-  noid fossa. However, large series of cases with success in this  technique lacks the scientific evidence of growth similar to  the unaffected joint, and reports of under- and overcorrection  are plenty in literature.   Patients with Type 3 deformities require total reconstruction  of the TMJ, i.e. the glenoid-zygomatic complex region and  the ramal-condylar unit. For the growing adolescent due to  growth completion, glenoid reshaping and costochondral  graft reconstruction of the RCU may be undertaken. Total  alloplastic joint reconstruction with concomitant orthogna-  thic surgery should be done in adults.   Posterior distraction of existing mandibular segment to  create ramal-condylar unit has ended up with limited success  due to lack of posterior support of distraction advancing seg-  ment and unpredicted movement in 3D dimensions. It was  found in authors’ experience that the correct direction con-  trol of upwardly directing condylar segment is difficult to  achieve towards a missing or defective glenoid fossa, and  many times the position can alter more medial and anterior  than expected rather than posterior towards external auditory  meatus.   The minimal asymmetry and deformity associated with a  Type 1 HFM may be amenable to minor surgical corrections  such as genioplasty (Fig. 78.22a, b). Since the occlusion may    Fig. 78.22 (a, b) Diagrammatic representation of surgical management of Type 1 Kaban-Pruzansky (a) deformity with isolated genioplasty for   In cases with minimal asymmetry where the patient is not  willing to undergo a surgery of the entire maxilla-mandibu-  lar complex, it is possible to achieve facial midline symmetry  by means of altering the midline chin and mandibular body  orientation through an extended operation involving the  basal bone of the chin and body of the mandible. It was pub-  lished by Paul C Salins in 2008 [36]. The author of this chap-  ter was happy to have learned this technique from Salins  himself and greatly understood the concept of this 3D move-  ment of genial bone along with body and ramus of the man-  dible to the unaffected side without altering the occlusal  relationship of the maxilla or mandible.   But this technique had obvious disadvantage in the form  of significant relapse due to large movements and require-  ment for multiple points of fixation.    At this juncture, the author of this chapter has designed a  distractor which can be placed below the lower border of the  mandible to move the genial-body-ramus unit in desired  direction by incremental distraction similar to other distrac-  tion protocols. This completely eliminated the need for any  plate usage, better stability without relapse and more or less  excellent unlimited movement in all three directions. This is  completely a basal bone distraction which can be either per-  formed in isolation or in combination with other distractions  and osteotomies of the maxilla-mandibular skeleton  (Figs. 78.23a, b, 78.24a, b, and 78.25a, b).   One of the key advantages of MDO is that the bone move-  ment produces good contour of the chin area along with flat  unaffected part of the mandible, and it obviously stretches  and accommodates the redundant excess submental-    Fig. 78.23 (a, b) Orthomorphic correction of deficient mandible. (a) Diagrammatic representation of a left sided HFM, (b) osteotomy design for    Bimaxillary surgery is planned to achieve the follow-  ing goals:  Maxilla and midface    1. Bilateral sagittal split osteotomy procedure to cor-  rect the occlusal canting and yaw correction.   As explained earlier, types 2B and 3 patients require recon-  struction of the TMJ as the primary goal. This may be exe-  cuted either as a Stage 1 correction with only  maxillomandibular correction or as Stage 2 with joint recon-  struction (Fig. 78.27).   Thus, although skeletal correction improves the dental occlu-  sion and skeletal symmetry, it may accentuate the existing soft  tissue discrepancy. Soft tissue augmentation should be taken up  after hard tissue correction. Various methods are available such  as fat transfer, microvascular free flap for adipose tissue transfer  and alloplasts such as Medpore and nanogels to give shape to  deficient soft tissue (Fig. 78.28a, b).   HFM has been reported as a nonprogressive disorder, i.e.  proportional deficiency of the face is maintained throughout  the growth of the child. Indications for early reconstruction of  the RCU during early childhood, especially in types 2B and 3    Fig. 78.24 (a, b) Pictorial view of basal bone osteotomy and orthomorphic distractor placement. (a) Basal view showing distractor position for  orthomorphic distraction method, (b) frontal view of the distractor postion    Fig. 78.25 (a, b) Indigenous distractor made and modified, placement showed in a dry skull mandible. Note the placement of distractor on the  basal bone. (a) frontal view of distractor placement, (b) basal view    Fig. 78.26 (a, b) Orthomorphic distraction done in a patient having hemifacial microsomia. (a) Pre- and (b) postoperative photograph showing  achievement of anatomic chin and contour and mandibular asymmetry    Fig. 78.27 (a—d) Diagrammatic representation of surgical management of Type 2 Kaban-Pruzansky deformity (a). Derotation of the maxilla-  mandibular complex by orthognathic surgery (b and c). Midline skeletal correction with a centring genioplasty (d)    classes, has mixed reports of success. Longitudinal studies  provide evidence for stable results with early osteodistraction  in mild-to-moderate skeletal deformities [20, 33, 34] (Type 1  and Type 2A). However, the role of mandibular distraction  may be more relevant in severe deformities. It is also sug-  gested that early intervention makes definitive final correction  easier to achieve, since the extent of deformity is reduced.    Long-term evaluation of growing HFM patients treated by  surgical correction and distraction osteogenesis depends on  two main factors: the time of intervention and the severity of  the skeletal deformity. According to Hollier et al., by achiev-  ing normal mandibular dimensions at a young age, it is    Fig. 78.28 (a, b) Soft tissue augmentation using abdominal autologous fat transplant. (a) pre-surgical frontal view demonstrating severe right  sided deficiency in a patient with HFM, (b) frontal view showing soft tissue augmentation    hypothesized that the maxilla, overlying muscle and soft tis-  sue envelope may develop along with a balanced functional  matrix [19]. Proponents of mandibular distraction believe that  an early intervention would prevent the secondary compensa-  tions from taking place or would unravel the compensations  at the onset. This means the contralateral and ipsilateral dis-  tortions can be reduced in comparison with patients not  undergoing distraction in the younger age (Figs. 78.29a, b  and 78.30). Clinicians have found that early distraction can  also prevent the long orthodontic decompensation phase fol-  lowed by orthognathic surgery. Considering severity of defor-  mity, the more severe deformities demonstrate less stable and  favourable results when attempted early.   The indications for early skeletal correction maybe (1)  compromise of airway necessitating immediate mandibular  lengthening irrespective of age and (2) negative psychologi-  cal impact on the child in school-going age.   In authors’ experience irrespective of area and direction  of distraction in the mandible or in maxilla in younger age,  the following findings were concluded in 20 years of clinical  follow-up:    1. It is difficult to predict the future growth of already dis-  tracted area of bone though claims of growth potential  on distracted bone have been debated by many.    . In majority of the cases, the intensity of the severity of    the disease has reduced due to distraction than simply  curing the disease as the age advances.    ated corrections of teeth on a weak hypoplastic bone are  difficult at least in some cases.    patients to balance the soft tissue profile equal on both  sides.    necessary in some cases especially Type 2B and Type 3  cases and accepted as standard norms to finish orthodon-  tic alignments.    . The airway disease is not cured to 100% in all cases due    pletely, so caution should be given to patient the com-  promised results outcomes in extreme cases of  asymmetry.    (a, b) Long-term results of patient treated with mandibular distraction in childhood. (a) frontal photo of patient with right sided HFM    at, t, (b) frontal photo of patient after 8 years follow up    10. Alloplastic prosthetic condyles should be reserved as a  last resort if all other techniques fail to achieve a func-  tionally stable total agenesis of condyles [21].    The assessment of facial topography using non-invasive  methods, such as laser surface scanners, stereophotogram-  metry or ultrasonographic measurements, has been recently  reported in several studies. Particularly, 3D stereophoto-  grammetry for the evaluation of soft tissue surface facial  asymmetry has been extensively studied [36]. In distraction  osteogenesis, recent advancements like automated distrac-  tion using battery-operated and hydraulic distractors have  been tried. Since hemifacial microsomia involves bone aug-  mentation in a multiplanar fashion, the advent of curvilinear  and multiplanar distractors has greatly helped overcome this  challenge [37, 38].   Tissue-engineered osteogenic material comprising of  culture-expanded mesenchymal stem cells (MSCs) and  platelet-rich plasma (PRP) can now be injected at the dis-  traction site to ensure more predictable bone formation. Not  only animal studies but also clinical trials have demon-  strated that this material can effectively regenerate osseous  tissue [39, 40].    Treacher Collins syndrome (TCS), also called mandibulofacial  dysostosis (MFD), is an autosomal dominant disorder of cranio-  facial development with variable penetrance. It has a worldwide  incidence of | in 50,000 live births (Gorlin et al. 1990) [41].  Early descriptions were given by Berry (1889), Treacher Collins  (1900) and Franceschetti and Klein in 1949. Therefore, this  entity is also named as Berry’s syndrome and Franceschetti-  Zwahlen-Klein syndrome [42, 43]. While 40% of TCS cases  have a previous family history, 60% of cases could possibly  arise as a result of de novo mutations (Jones et al. 1975) [44].  The TCOF1 gene plays an important role during early  embryonic development for tissues derived from the first and  second branchial arches, ectodermal clefts and endodermal  pouches. TCOF1 gene encodes a nuclear phosphoprotein  “Treacle” that may serve as a link between rRNA gene tran-  scription and pre-rRNA processing. TCOF1 mutation leads  to abnormal neural crest cell migration or anomalies in the  extracellular matrix [45]. Sulik et al. also documented exces-  sive cell death in the maxillary and mandibular processes of  the first branchial arch and the apical ectodermal ridge of the  limb bud [46]. These deductions have been made on the basis  of experimental studies wherein animals were exposed to    Fig. 78.30 (a, b) Definitive skeletal management of patient with  HFM. (a) Preoperative Frontal photo of patient with right sided HFM at  15 years of age. He underwent mandibular distraction for correction of    teratogenic cis- or trans-retinoic acid during embryonic  development. Recently, Dauwerse et al. [47] detected muta-  tions in genes encoding subunits of RNA polymerases I and  IU in Treacher Collins patients.   Normally, prenatal diagnosis is recommended for fami-  lies with a history of TCS using fetoscopy or ultrasound  imaging [USG]. Prenatal diagnosis using either of these  methods can only be performed in the second trimester of  pregnancy (approximately 18 weeks). Due to the late nature  of the diagnosis, termination of pregnancy can be a particu-  larly traumatic procedure. Imaging with USG has improved  immensely in recent years [e.g. 3D sonography], allowing  non-invasive prenatal diagnosis to be made. However, mild  cases of TCS are still difficult to diagnose. Genetic counsel-  ling is highly recommended for affected individuals and  their families for prevention of further affected child birth.    asymmetry followed by second stage Bi maxillary orthognathic surgery  at 18 years of age (Fig. 78.7a). (b) Stable skeletal results after a 7 year  followup when patient is 25 years of age    The complete spectrum of features which can be present are  explained in the table below [48] (Table 78.7).   A case of Treacher Collins syndrome in a 13-year-old  female with the following features (Fig. 78.3 1a, b):    e Eyes: Antimongoloid palpebral fissures are short and  slope laterally downwards with either a notch or colo-  boma of the outer third of the lower eyelid. Lashes are  absent medial to coloboma.   ¢ Face: Bilateral and usually symmetric hypoplasia of facial  bones is present, e.g. malar and mandibular bones.  Depressed cheekbones, receding chin, tongue-shaped  process of the hair that extends towards the cheek and  large down-turned mouth can be identified.    e Ears: Malformation of the external, middle and inner ear,  with low implantation of the auricle which is common.  The pinnae are often crumpled and misplaced towards the  angle of the mandible. Bat-fan ears, deafness, microtia,  extra ear tags and blind fistulas [which may occur any-  where between the tragus and the angle of the mouth] are  the other common findings.   Antimongoloid slant of palpebral fissures  Colobomata and hypoplasia of the lower lids and  lateral canthi   Class II or III malocclusion open bite  Hypoplasia of the malar bones    ¢ Oral findings: Cleft palate, congenital palatopharyngeal  incompetence, high-arched palate and a narrow maxillary  and mandibular arch with dental crowding are common  (Fig. a-e).   ¢ Nose: The nose appears larger due to the hypoplastic mid-  face skeletal structures. Hypoplastic alar cartilages, nar-  row nares and obliteration of the nasofrontal angle are  also common.    The conventional OPG and the lateral and frontal cephalo-  metric image are pivotal in diagnosing TCS along with clini-  cal correlation. The OPG helps identify the following:  hypoplastic condyle with a short condylar neck, absent artic-  ular eminence, shortened ramus-condyle unit and severely  hypoplastic coronoid process (Figs. and ). The  lateral cephalogram shows a severely retrognathic mandible  with microgenia, clockwise-rotated maxillomandibular com-  plex and a reduced posterior airway space. However, three-  dimensional computed tomography [3DCT] is the gold  standard in diagnosis as well as treatment planning  (Fig. a—c). The features that are remarkably seen on the  3DCT are hypoplasia of the orbito-zygomatic complex,  poorly developed lateral orbital and supraorbital ridges,  mandibular hypoplasia and reduced overall facial width. The  orbits are hyper-teloric and the infraorbital foramen is usu-    Fi i (a, b) Case of a 13-year-old female with Treacher Collins syndrome, (a) profile and (b) frontal photos (Also see Fig. )    Fig. 78.32 (a-e)Intraoral pictures of the same patient in Fig. 78.30 showing operated cleft palate, mixed dentition stage with severe crowding.  (a—c) frontal and lateral intra-oral dental views, (d) maxillary occlusal and (e) mandibular occlusal views    Fig. 78.33 Lateral cephalogram of the same patient in Fig. 78.31  showing reduced posterior airway space, micrognathia and microgenia    ally absent. The paranasal sinuses are often small and may be  completely absent. Furthermore, the mastoids are not pneu-  matized and are frequently sclerotic. The cranial base is also  progressively kyphotic [48]. Lastly, these patients require    long-term follow-up in order to evaluate the effects of man-  dibular growth, airway dimensions, degree of surgical relapse  and the need for additional surgical intervention.    A classification system of the orbito-zygomatic skeletal  deformities seen in TCS has been proposed by Nikkah D  et al. The classification is designed to characterize the  degree of deformity and as a guide to the reconstructive  planning [49]. Treatment planning becomes complex as  TCS can have a variable presentation with respect to the  severity of the hypoplasia/dysplasia of the skeletal and soft    Fig. 78.35 (a—c) 3DCT view of TCS patient showing hypoplasia of orbito-zygomatic complex. (a) Right lateral view demosntrating type 2b defor-  mity, (b) frontal view showing type 2b deformity on the right and type 3 deformity on the left, (c) left lateral view showing type 3 deformity    Fig. 78.36 (a,b) Type 1: Patients have the entire orbito-zygomatic complex present but the region is dysplastic and hypoplastic    tures and resulting functional deformity. Thus, the chal- zygomatic temporal process and a lateral orbital wall that  lenges faced in treating TCS are similar to those faced in is either dysplastic (2a) or absent (2b) (Fig. 78.35a, b).  treating HFM. ¢ Type 3: a hypoplastic zygomatic body and dysplastic    ¢ Type I: orbito-zygomatic complex present but, dysplastic ° Type 4: complete absence of the entire orbito-zygomatic  and hypoplastic (Fig. 78.36a, b). complex (Fig. 78.37a, b).    Fig. 78.37 (a, b) Type 4: Is the most severe with complete absence of the entire orbito-zygomatic complex    There is not always a symmetrical classification as 25%  of the TCS demonstrated asymmetry.    Differential diagnosis of TCS includes acrofacial dysostosis  (Nager and Miller syndromes) and oculo-auriculo-vertebral  spectrum (hemifacial microsomia and  Goldenhar  syndrome).   Nager syndrome has facial features similar to that of TCS. In  addition, the thumb[s] may be hypoplastic, aplastic or dupli-  cated, and there may be fusion of the radius and ulna. Miller  syndrome also has features similar to TCS. Ectropion or out-  turning of the lower lids is an additional diagnostic feature.  Clefting of the lip and palate is more common in this syndrome  than in TCS [50]. HFM primarily affects development of the  ear, mouth and mandible. Goldenhar syndrome has a spectrum  of deformities that include those of HFM in addition to verte-  bral abnormalities and epibulbar dermoids [51].    Though there have been immense medical advances in terms  of in utero surgery, stem cell therapy and genetic manipula-  tion, there is currently no treatment for TCS in utero.  Treatment is performed postnatally according to the nature  of the deformity and severity of functional disturbance [52].    These issues can challenge clinicians from birth to adult-  hood as concerns vary from aesthetic to functional in nature.  Thus, a multidisciplinary approach is indispensable for  achieving optimal outcomes.    78.2.6.2 Airway Management  Syndromic patients [e.g. TCS] with micrognathia suffer  from OSA frequently due to narrowing of the upper airway    [53]. Despite respiratory effort, partial or complete obstruc-  tion of the upper takes place, leading to frequent episodes of  oxygen desaturation and sleep disruption. In the long term,  OSA can harm an individual’s physical and mental health, as  has been documented recently in the literature [54].  Respiratory compromise is due to two reasons:    (i) Maxillary hypoplasia, constricting the nasal passages  and resulting in a degree of choanal stenosis or atresia.   (ii) Mandibular micrognathia and a retro-positioned tongue  obstructing the oropharyngeal and hypopharyngeal  airway.    Earlier, long-term tracheostomy was the only solution  available for severe cases of infantile OSA. However, long-  term tracheostomies are commonly associated with morbidi-  ties like tracheomalacia, chronic bronchitis, throat tightness  and dislocation of the tracheostomy tube [55] (Fig. 38a,  b). Today, distraction osteogenesis [DO] has become the  favoured treatment method for TCS patients with  OSA. Mandibular advancement by means of DO helps in  increasing the posterior airway space, thus relieving the  symptoms of OSA and preventing severe respiratory distress  [56]. Due to the unique mandibular and oropharyngeal anat-    (a, b) Photograph of a 4-year-old male with TCS. Patient had history of hospitalization due to respiratory distress. Tracheostomy tube    Fig. 78.39 (a, b) Mandibular advancement using distraction in neonates to increase posterior airway space as a treatment of obstructive sleep  apnoea. (a) Position of the distractor on the mandible, (b) Emergence of activation port in the retromandibular region    omy of TCS patients, a fibre-optic-assisted intubation  method similar to that described by Ellis et al. can be suc-  cessfully used [57].   Paediatric mandibular advancement was initially per-  formed using bilateral external distractors which are advan-  tageous because of their ease of use, manipulation and  versatility [ 58]. However, external devices also create aes-  thetic [e.g. scarring] and social problems. Another important  point to be noted is that retention period of such devices is  reduced and an increased relapse rate is seen compared to  internal distractor devices [59]. If the child is extremely  uncooperative and parents are unable to maintain and moni-  tor the external distractors, an internal distractor should be  used (Fig. 78.39a, b).   Recently, paediatric mandibular distraction for OSA has  been discouraged in many centres around the world due to  concern of permanently damaging the teeth buds. Instead,  tongue lip adhesion (TLA) has been popularized by many  centres instead of DO as it has significantly lower morbidity.  After the airway improves, better feeding and weight gain  are expected and cleft palate closure is done. Subsequently,  TLA release can be attempted [60]. In comparison to DO,  the TLA needs stricter postoperative care in intensive setup  as feeding and breathing need to be assessed regularly for a  week at the minimum.    78.2.6.3 Feeding Problem  The abnormal or hypoplastic craniofacial issues in TCS can  sometimes produce severe feeding problem for infants, lead-  ing to weight loss and failure to thrive. Most feeding prob-  lems relate to cleft lip and palate, retrognathic jaws and  airway problems. Ideally, a craniofacial feeding manage-  ment team should guide the parents regarding position of  feeding, type of nutrition and dietary plan for such children.  Position (holding the baby upright or supporting the  cheek and jaw while feeding) is important to avoid aspiration.    It is also preferable to do a video-fluoroscopic swallow study  (VFSS) to understand the swallowing pattern of the patient  and its coordination with breathing [61].   Primary palatoplasty for closure of the cleft palate should  be done once the patient gains weight, to assist in normaliz-  ing the swallowing pattern without nasal regurgitation.   Individuals with TCS have a tendency towards a shorter stat-  ure, at least early in life. Intelligence is usually unaffected,  but brain and behavioural anomalies such as microcephaly  and psychomotor delay have been occasionally reported as  part of the condition. Additionally, the facial deformity of  this syndrome may affect psychosocial development, school  adjustment and other milestones. A psychologist or social  worker should be made available for evaluation and counsel-  ling if needed.   In the Indian scenario, poor parental awareness, lack of  medical advice, social taboos and feeding difficulties lead to  failure to thrive among TCS infants and children belonging  to lower socio-economic classes. Psychological stress during  schooling [e.g. marked out as different by peers] is one of the  more challenging issues to be addressed throughout the life  of the patient.   Isolated cleft of the soft palate is the most common form of  cleft in TCS. Complete cleft palate up to the alveolus may  also be seen. Closure of the soft palate is routinely done at  the end of | year. Meticulous dissection and suturing of soft  palate muscles can produce excellent results, nearing to that  of a normal palate. Postoperative maintenance of oral  hygiene is necessary and can become challenging in these  children for fear of aspiration. Velopharyngeal insufficiency  [VPI] is a common issue in these children. VPI can be cor-    rected secondarily with intra-velar palatoplasties or buccal  advancement flaps for velar lengthening.   Eye anomalies include aberrations in the extraocular muscle  function, corneal exposure difficulties and visual acuity.  Ophthalmologic issues may include vision loss (37%),  amblyopia (33%), refractive errors (58%), anisometropia  (17%) and strabismus (37%). A thorough paediatric ophthal-  mological assessment should be done to establish proper  management.   A 3D CT of the petrous temporal bones should be done to  accurately assess the external auditory canal and middle and  inner ear anatomy. TCS patients with microtia can have con-  genital aural atresia and extremely narrow canals, leading to  significant conductive hearing loss as the bone blocks pas-  sage of sounds to tympanic area and middle ear. Furthermore,  exfoliated skin cells and ear wax cannot drain out, leading to  otitis media and occasionally form cholesteatoma. Despite  hearing loss, these children tend to grow normally. However,  the chances of developmental cognitive deficits are not  uncommon.    Microtia Correction  Microtia ear correction can be done when the patient is  around 6 to 7 years old, an age at which external ear develop-  ment is complete. The most preferred way of auricle recon-  struction is the use of autogenous rib cartilage, in a staged  manner. The rib cartilage is harvested from the sixth to the  ninth rib. The sixth and seventh rib cartilage are utilized to  form the base of the framework. The triangular fossa and  scapha are carved in the superior portion of the previously  created cartilaginous base. The eighth rib cartilage is then  carved to replicate the helical rim. The carved cartilage is  then inserted under the skin in the region of the missing ear,  with or without skin expansion (Fig. 78.19).  Bone-conduction hearing aids such as the bone-anchored  hearing appliance (BAHA) or a middle ear implantable pros-  thetic device can significantly improve hearing in these  patients.   Nasal deformities can be classified as external or internal in  nature. Commonly seen external nasal deformities are the  dorsal hump (73%), external deviation (<55%), bifid or bul-  bous nasal tip (55%) and columellar septal luxation (55%).  Commonly seen internal nasal deformities are nasal obstruc-  tions due to septal deviation and presence of spurs. Due to  presence of the above structural deformities, functional    problems, e.g. snoring and impaired phonation, are com-  monly present in these patients.   A detailed physical examination along with nasal endos-  copy and 3D CT of the nasal and paranasal regions can help  identify all the deformities present. The commonly per-  formed procedures that should be paid attention to are dorsal  hump reduction, correction of the deviated external osseous  deformity, septoplasty and tip plasty.    ¢ Due to the presence of an anterior open bite and compul-  sive mouth breathing, there is an increased risk for poor  oral hygiene. This is evidenced by the face that up to 60%  of TCS patients need dental care [e.g. restorative treat-  ment]. However, the difficulty of performing even simple  dental procedures is far higher due to reduced mouth  opening, presence of concurrent medical co-morbidities  [e.g. congenital heart defects], decreased posterior airway  space and hearing loss [61, 62].   ¢ During the late mixed dentition phase, orthodontic treat-  ment aims to increase the transverse dimensions of the  constricted maxilla [e.g. quad helix]. In the permanent  dentition phase, the fixed therapy is used in order to  achieve intercuspation and arch levelling.   ¢ For moderately severe cases, the final goal is to prepare  the patient for orthognathic surgical correction of the  anterior open bite and skeletal class 2 relationship [63].  Studies have established that bimaxillary orthognathic  surgery gives stable long-term results in TCS patients  [64]. Sometimes, additional procedures to improve the  shape of the chin are required. Figures 78.40a, b, 78.41  and 78.42a, b show double sliding genioplasty done in a  patient in early age due to psychological impact owing to  the facial appearance.   e For severe cases, DO with external distractors is the ideal  surgical intervention wherein gonial angle control is neces-  sary for increase in height of the ramus and lengthening the  body of the mandible. In this aspect, multi-vector devices  have an advantage with respect to the ability to control the  transverse width during distraction (Fig. 78.43a—f).   The adult patient with TCS has a convex facial profile due to  severe mandibular retrognathia. However, the horizontal pro-  jection of the maxilla to the cranial base remains normal.  Over the growth period, the facial convexity angle remains  relatively constant, thus confirming that the facial profile  morphology of the infant with TCS remains similar to that of  the adult.    Fig. 78.40 (a) Preoperative and (b) postoperative lateral cephalogram radiographic view of a patient with Treacher Collins syndrome who under-    The total facial height is often excessive, with a normal  upper facial height. This is due to combination of anterior  open-bite malocclusion, mandibular retrognathism and chin  dysplasia. Hypoplasia of the orbito-zygomatic complex is a  characteristic feature. These hypoplastic facial skeletal fea-  tures have variable effects on the TMJ, masticatory function  and facial soft tissues and expressions.   Both the maxilla and mandible are rotated in a counter-  clockwise rotation. Thus, the maxillary and mandibular  plane angles are excessively steep. Clinically, this translates  to a shorter posterior facial height in TCS patients.   The mandible size is evidently decreased in both the  ramus height and the body length. The gonial angle is obtuse  with anti-gonial notching. The steepness due to clockwise  rotation of the maxillomandibular complex along with the  anterior and posterior vertical height disproportions and  severe horizontal deficiency is reflected in the A-point-to-B-  point discrepancy. All of these cephalometric findings  explain the clinical facial dysmorphology.   Incidence of cleft palate with or without cleft lip (and cho-  anal atresia of the nasal cavity) is variable. Dental anomalies are  present in 60% of individuals such as tooth agenesis enamel,  opacities and ectopic eruption of the maxillary first molars.   Treatment of the skeletal defect in the orbito-zygomatic  region varies according to the severity of the defect. The fol-  lowing classification categorizes the deformities according  to severity and their treatment. Since this region attains  growth by age of 9, most surgeons postpone definitive recon-  struction up to this age.   Type I defects: The orbito-zygomatic complex is dys-  plastic and hypoplastic. Type 1 represents the mildest  form of the defect and can be easily treated by autologous  fat, either by liposuction and injection or dermis fat graft  [65]. The merit of autologous fat grafting is that it is  repeatable with minimal donor site morbidity and can be  done before growth completion. It is ideal for growing  children who are psychologically affected due to a poor  facial appearance. The disadvantage of this technique is  that it may have to be performed repeatedly to maintain  the volume of correction.   Fat transfer can be used alone for correction of minor  defects. It has more of an adjunctive role in severe defects  after wherein hard tissue augmentation is the preferred  intervention.    Fig. 78.41 (a, b) Extraoral profile view showing marked improvement in the lower third of the face. (a) Pre-surgical profile photo showing retro-  genia (Fig. 78.31al), (b) post-surgical profile photo after a double sliding genioplasty, showing good chin prominence    lS, y  ©Association of Oral and Maxillofacial Surgeons of India  Fig. 78.42 (a-c) Intraoperative view of double sliding genioplasty genioplasty with fixation (also see Figs. 68.32 and 68.33 for use of    done for the same patient as in Fig. 78.41. (a) Surgical exposure of the double sliding genioplasty in other clinical situations)  genium, (b) osteotomy design marked on the chin and (c) completion of    Fig. 78.43 (a-f) Case of TCS who underwent early osteodistraction. (a, b) Pre-operative frontal and profile photos, (ce, d) Frontal and profile  photos post distraction with bilateral uni-directional distractors, (e, f) Frontal and profile views after five years follow-up    Type 2 defects: Defect consists of hypoplastic zygomatic  body with a reduced zygomatic temporal process and a dys-  plastic or absent lateral orbital wall. This class of defect  usually requires surgery to address the bony deficiency.  Studies have established that a malar osteotomy offers bet-  ter contour as compared to onlay bone autografting [66].  Though the malar osteotomy is aimed at correcting the  width of the midface, it is difficult to augment anteroposte-  rior projection by osteotomy only. It should be noted that  this defect is characterized by a deficient vertical dimen-  sion as well. Thus, a zygomatic osteotomy is preferably  combined with an onlay graft. The Mommaerts zygomatic  osteotomy is favoured in some units because it does not  alter orbital dimensions. Alloplastic materials [e.g.  Medpore] can be very effective alternatives to the tradi-  tional onlays [67].    Types 3 and 4  The defects range from severe hypoplasia/dysplasia to com-  plete absence of orbito-zygomatic bony complex. Patients  belonging to these groups require bony augmentation. In  adults, alloplastic augmentation with patient-specific  implants can be considered as they provide optimal results.  In general, the zygomatico-maxillary-orbital bone com-  plex can be reconstructed using an autologous free bone or  regional pedicle graft. Non-vascularized autologous bone  grafting for larger defects is increasingly prone to loss of  graft due to infection and resorption if not fully covered by  surrounding soft tissue. Studies have established that resorp-  tion occurs due to reduced vascularity and increased func-  tional loads on the graft. Therefore, it is prudent to line the  bone grafts by soft tissue on its inner side in the proximity of  maxillary sinus and nasal cavity [68].    Calvarial bone grafts have been used for reconstruction  of midface in various craniofacial deformities. Full-  thickness calvarial grafting outcomes are more stable in  the long term due to the dense cortical nature of the graft  (Fig. 78.44a, b). Studies [69] have also established that  dense membranous bone grafts [e.g. calvarial] are more  effective than endochondral grafts [e.g. iliac crest] in the  craniofacial skeleton. Calvarial bone grafts have become  popular because of their low resorption rates and minimal  donor site morbidity for orbito-zygomatic complex recon-  struction [70].    Hemifacial microsomia and Treacher Collins syndrome are  both congenital craniofacial anomalies that negatively impact  the physiological and psychological wellbeing of an individual  [71]. Due to multidimensional nature of the deformity, a multi-  disciplinary holistic approach is required with proper guidance  and counselling of the patients at every level of treatment.  However, with the advances in regenerative sciences and genetic  engineering, diagnosis and management of such congenital  deformities is becoming less challenging. Disclosure Authors  have no financial conflicts to disclose.    Fig. 78.44 Skeletal correction for TCS. (a) Calvarial graft harvest for recsontruction of zygoma, (b) graft in place, (c) osteotomy design for  orthognathic correction with bimaxillary surgery and genioplsty, (d) diagram showing post orthognathic final correction    Case of TCS who underwent early osteodistraction. Note the  mandibular advancement using bilateral unidirectional dis-  tractors. Follow-up after 5 years. Patient is currently under-  going orthodontic treatment.    Case 2: Hemifacial Microsomia (Figs. 78.45a-e,  78.46a-c, 78.47a, b, 78.48a-c, 78.49a—c, 78.50a, b,  78.51, 78.52a—d, 78.53a, b)    Case of a 20-year-old girl having HFM, undergoing osteot-  omy for asymmetry correction. Preoperative photographs,  radiographs and CT scans showing the extent of asymmetry.  Pre-surgical orthodontics for levelling and alignment. Virtual  planning to fabricate CAD-CAM splint. Final postoperative    Fig. 78.45 (a-—e) Preoperative views of a female patient with facial asymmetry and deviation towards the left side    Fig. 78.47 (a, b) Preoperative (a) lateral cephalogram and (b) OPG showing Class II skeletal profile with left-sided TMJ deformity    Fig. 78.50 (a, b) Virtual planning using 3D photogrammetry. (a) soft tissue reconstruction from the CT data, (b) superimposition of the patients  photograph on the CT model    Fig. 78.51 Virtual planning of orthognathic surgery to correct pitching, roll and yaw defect of the maxilla and mandible with genioplasty    Fig. 78.52 (a—d): Pre (a, c) and post operative (b, d) photograph showing correction of asymmetry in patient with HFM    Fig. 78.53 (a, b) Postoperative (a) lateral cephalogram and (b) OPG  showing correction of maxillomandibular relation. Refer to Fig. 78.47  for pre-operative xrays    1. Posnick JC. Hemifacial macrosomia: evaluation and treatment.  Principles and practice of orthognathic surgery. St. Louis, Missouri:  Elsevier; 2014.   2. Brandstetter KA, Patel KG. Craniofacial Microsomia. Facial Plast  Surg Clin North Am 2016 Nov;24(4):495—5 15. Review.   3. Poswillo D. The aetiology and pathogenesis of craniofacial defor-  mity. Development. 1988;103(Suppl):207-12.   4. Scambler PJ. The 22q11 deletion syndromes. 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Six year’s expe- of mandibulofacial dysostosis (Treacher Collins syndrome). Plast   of malar deficiency. J Oral Maxillofac Surg Off J Am Assoc Oral 71. Murray JE, Kaban LB, Mulliken JB. Analysis and treatment of   Maxillofac Surg 1999;57(1):8e13. discussion 4e5. Epub 1999/01/23. hemifacial microsomia. J Craniofac Surg. 1985;33:377.    68. Smolka W, Eggensperger N, Kollar A, Iizuka T. Midfacial recon-  struction using Calvarial Split bone grafts. Arch Otolaryngol Head  Neck Surg. 2005;131(2):131-6.    Open Access This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.  org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropri-  ate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.   The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in  a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.   The different presentations of craniosynostosis form the  majority of the workload of craniofacial services, and it is  important to note that the surgical interventions only form a  small part of the overall management of this vulnerable  group of patients and their families.    Craniosynostosis is defined as the premature fusion of one or  more of the cranial sutures. This premature fusion can either  be an isolated disorder (e.g. sagittal synostosis) or form part  of a syndrome (e.g. Apert syndrome). In many cases the  resultant head shape is typical of the involved suture such  that the Greek/Latin descriptive terms are used synony-  mously with the description of the affected suture. For exam-  ple scaphocephaly (boat-shaped head) is used to describe  sagittal synostosis; however this approach can lead to confu-  sion as can be seen in the use of the term plagiocephaly (flat  head) which may refer to a unicoronal synostosis but also  can be used in unilateral lambdoid synostosis, skull base tor-  sion, the deformity resulting from torticollis and positional  skull deformities. For this reason it is probably best to avoid  the Latin/Greek descriptive terms and identify the affected  suture(s) by name.   The majority of craniosynostoses are primary in nature  and congenital; however a small proportion are termed    D. Koppel   Consultant Craniofacial/Oral & Maxillofacial Surgeon, Clinical  Director Surgery & Gastroenterology, Clinical Lead Scottish  National Craniofacial Service for Children and Young People,  Royal Hospital for Children, Glasgow, UK    © The Association of Oral and Maxillofacial Surgeons of India 2021    secondary—caused by another pathology, usually result-  ing in reduced brain growth as seen in microcephaly or  post-shunting.   In the majority of cases, no cause for the synostosis is identi-  fied, but in an increasing proportion (currently about 25%), a  mutation is identified. A significant proportion of these  mutations are related to six genes FGFR2, FGFR3, TWIST,  EFNB1, TCF12 and ERF, however there is an increasing fre-  quency of additional mutations being identified by more  complex genetic analysis.   The incidence of identifying a mutation is much higher in  syndromic craniosynostosis cases (69%), but the rate of  mutation identification in the non-syndromic cases is increas-  ing (currently 5%) particularly in the bicoronal, multisuture  and unicoronal (in decreasing frequency) [1].   These genetic advances have assisted in the diagnosis of  these conditions and influence the genetic counselling but  have yet to impact on the management of the resultant prob-  lems related to the premature suture closure. As the mecha-  nisms of sutural control and homeostasis are elucidated,  novel therapies may be introduced.   Microcephaly and babies who have been shunted as well as  other systemic conditions such as sickle cell disease, thal-  assaemia and rickets can lead to synostosis usually affecting  all the sutures. In cases of microcephaly, it is important to  differentiate between a primary pansynostosis resulting in a  small head often with raised intracranial pressure from a sec-  ondary synostosis with normal intracranial pressure [2].    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1-15-1346-6_79    The incidence of craniosynostosis ranges from | in 1400 to  1 in 2100 live births worldwide with a slight male  preponderance.    The classification of craniosynostosis has, in recent years,  changed; the previously utilised terminology of simple and  complex, referring to single-suture and multiple suture  abnormalities, respectively, has been abandoned. It has little    utility and is in fact misleading—the deformity as a result of  a unicoronal synostosis is extremely complex and as more is  understood about the genetic basis the more complex the  condition becomes.   In terms of utility, the craniosynostosis is best classified by  the suture(s) involved and whether this is associated with a syn-  drome (i.e. other abnormalities). See Table 79.1 and Illustrations  79.1, 79.2, 79.3, 79.4, 79.5, 79.6 and 79.7. The condition can be  further defined by the genetic abnormalities. In general the syn-  dromic craniosynostosis cases tend to be more severe and have  a greater incidence of complicating features.    The care of babies and children with craniosynostosis is best  delivered in a centre with access to a full multidisciplinary  team. This team involves the core specialities of paediatric  neurosurgery and craniofacial surgery (either OMFS or plas-  tics based) as well as support from paediatricians, neonatolo-  gists, geneticists, respiratory specialists, ophthalmologists  and ENT surgeons. The input from specialist nurses and psy-  chologists is vital [4].    Flattened forehead on affected side with raised eyebrow and shallower orbit  Failure of forward growth of the hemiforehead with the ipsilateral ear also    Shortened AP—Coronal dimension  Flattening of whole forehead  Flattened supraorbital rims  Forehead bossing   affected Description of shape Diagram of shape Description  Metopic Trigonocephaly Illustration 79.1a, b    Illustration 79.2 (a, b) a b  Unicoronal suture affected  in anterior plagiocephaly    Hydrocephalus External ventricular drain, ventriculo-peritoneal  shunt, third ventriculostomy (in selected cases)  Elevated ICP Medical treatment with acetazolamide, steroids    The use of high-definition prenatal ultrasound has increased  the early diagnosis of both hydrocephalus and craniosynos-  tosis [5]. This facilitates the preparation of parents for the  birth of a child who is likely to have additional medical,  surgical and emotional needs. In these circumstances parents  getting to know the craniofacial team and being better  informed of the potential problems often makes supporting  them much easier.    In the perinatal period, care is directed at optimising the  airway, ensuring the child is well oxygenated, preventing  corneal damage (ocular protection) and confirming the  diagnosis. In the majority of single-suture abnormalities,  there are often no issues that prompt early intervention;  however in the complex syndromic cases, this is not the  case. Airway problems due to severe midface retrusion;  breathing disturbance due to central problems, often due to  posterior fossa crowding and Chiari malformation; corneal    Skull vault expansion, fronto-orbital advancement and  remodelling (FOAR), monobloc advancement +  implanted telemetric device    exposure secondary to midface and brow retrusion; and  associated non-craniofacial anomalies prompt more urgent  interventions. The necessity for such interventions is great-  est in the syndromic conditions such as Apert, Pfeiffer,  Crouzon and Carpenter syndromes. In cases where there is  significant midface retrusion, there may also be feeding dif-  ficulties [6].   In the severe cases, initial care is supportive. The airway  should be assessed and intervention initiated if necessary. It  is important to assess the oxygen saturation and the work of  breathing and correlate these findings with formal blood gas  measurements. This assessment can be augmented with a  formal sleep study, and on occasion simultaneous measure-  ment of intracranial pressure may be helpful. Airway support  can range from positional nursing, the use of a nasopharyn-  geal airway, intubation and in some cases tracheostomy. As  part of this assessment, when the airway is an issue of con-  cern, consideration should be given to performing a CT scan,  and this will be useful to look at cranial anatomy but also the  nasal anatomy, particularly to exclude choanal atresia. In  assessing the airway, babies often manage satisfactorily but  may suddenly decompensate with a minor upper respiratory  tract infection or whilst feeding [6].    Surgical intervention in this period is only undertaken when  the airway is such that no simple measures are able to over-  come the symptoms; often a period of intubation is helpful to  allow for a more thorough assessment rather than rushing to  either tracheostomy or a monobloc fronto-facial advance.  During this period parents and family members have to come  to terms with the often unexpected consequences of having a  child with additional needs and medical interventions. Early  and ongoing support needs to be delivered; this can and  should be through multiple avenues. Many such children are  born in institutions with little or no experience of the  condition(s), and this professional unfamiliarity often adds  to parental anxiety. For these reasons early contact with a  dedicated craniofacial team is invaluable. Specialist nurses,  psychologists and support groups can often ease the stress of  this difficult time [7].    The management of craniosynostosis in infancy is primarily  aimed at addressing the primary consequences of the premature  suture closure as well as dealing with the associated problems.  The management of the synostosis has, over the years,  evolved considerably and in some respect completed a com-  plete circle. The treatment is aimed at ensuring cranial vol-  ume is satisfactory to ensure that there is no elevation of ICP  (in the absence of hydrocephalus) as well as attempting to  normalise the head shape. The normalisation of head shape is  done to maximise the chances of a normal head shape at the  completion of growth. Initial treatment introduced in the sec-  ond half of the last century involved a procedure known as  suturectomy [8]. The principle of this was to excise the path-  ological, prematurely fused suture with the idea that removal  of the pathology would allow the skull to continue to grow  into a normal shape possibly aided by the continued growth  of the brain. This was found to be partially effective espe-  cially when done before the age of 18 months [9]. It was  however noted that in many cases re-fusion of the suture  occurred and a number of surgeons began wrapping the bone  edges on either side of the resected suture with silicone edg-  ing in an attempt to minimise the chances of re-fusion.  Unfortunately this approach did not prevent re-fusion, and  this often occurred on the dural side of the silicone edging. In  pansynostosis cases the sutures were excised and the remain-    der of the skull was morselised [9]. These simple techniques  have been superseded with more complex reconstructive  procedures involving suturectomy and remodelling. (See  case series examples (Figs. 79.2, 79.3, 79.4 and 79.5). When  the coronal sutures are involved, either unilaterally or bilat-  erally, and/or the metopic sutures, the mainstay of treatment  is a fronto-orbital advancement, with remodelling of the  affected bones. When the sagittal suture is involved, the  affected suture is excised and the remaining skull remod-  elled. The extent of remodelling varies from case to case but  can involve addressing the frontal bossing, bitemporal nar-  rowing and the occipital bullet [4]. These procedures involve  extensive exposure and blood loss with their attendant risks,  and for these reasons there has been a move to attempt to  correct these abnormalities with less invasive procedures.  These less invasive approaches utilise endoscopic suturec-  tomy coupled with active postoperative helmet therapy to  mould and harness the ongoing brain and hence skull growth  [10]; another approach has used a minimal access suturec-  tomy and specially designed springs to actively separate the  affected suture edges [11]. A further technique, particularly  in bicoronal or pansynostosis cases, is to utilise distraction  osteogenesis; a craniotomy of the occipital bone is per-  formed, and two or three distraction devices are applied;  these are then activated over a period of 2—3 weeks, expand-  ing the skull volume and in many cases improving the  posterior fossa crowding seen in such cases. For reasons not  fully understood, this technique often leads to a significant  improvement in the contour of the frontal bones [12].   In terms of timing of surgery, there is considerable varia-  tion between different centres. In general elective (not moti-  vated by functional concerns), suturectomy and_ skull  remodelling procedures are performed between the ages of  5 months and 2 years. The younger the patient, the greater  the contribution of normal brain growth in normalising head  shape; however the drawback of earlier surgery is the fragil-  ity of the skull bones and most importantly the risks of com-  plications—particularly excessive blood loss [13].   During this period patients are generally followed up to  monitor for signs of raised intracranial pressure, obstructive  sleep apnoea (OSA) and evidence of a significant change in the  rate of head growth as indicated by head circumference.  Discrepancies between the plots on the growth charts (Fig. 79. 1a,  b) for length, weight and head circumference as well as plots  crossing the centile lines should prompt further investigation.    Fig. 79.1 (a) (boys), (b) (girls) WHO UK growth the chart (a) and (b) is available Online at https://www.rcpch.ac.uk/resources/uk-who-growth-charts-0-4-years    Fig. 79.2 (2.1-2.9) Case series of sagittal synostosis. (2.1-2.4) prominent forehead and occiput. (2.5—2.7) Postoperative facial views of  Preoperative facial views of patient with sagittal synostosis aged patient with sagittal synostosis after full calvarial remodelling. (2.8 and  13 weeks. Note elongated A-P dimension and bitemporal narrowing with 2.9) Preoperative CT scan of the same patient with sagittal synostosis    Elevated ICP manifests as distressed behaviour, incon-  solable crying and headbanging with symptoms being  worse at night. When symptoms are combined with papill-  oedema, urgent intervention is indicated. The absence of  papilloedema does not exclude raised ICP, but its presence  is of significance. In cases of doubt, formal ICP monitor-  ing can be undertaken. In established cases the use of an  indwelling telemetric ICP measurement device may be  helpful [14].    Formal ophthalmological assessment should be under-  taken and appropriate intervention initiated. Regular assess-  ments are necessary to identify deterioration, particularly to  identify corneal exposure and avoid the development of  amblyopia.   Routine computerised tomography (CT) cross-sectional  imaging is not indicated, and the diagnosis can, in the vast  majority of cases, be made on clinical findings alone. In  cases where the diagnosis is in doubt or there is the suspicion  that there may be posterior fossa crowding, Chiari malfor-  mation or craniocervical abnormalities, a CT is indicated.  Magnetic resonance imaging (MRI) is indicated to investi-  gate the brain for structural abnormalities. The objective  with this very conservative approach to imaging is to mini-  mise the ionising radiation exposure, which has been demon-  strated to adversely affect brain development and damage the  developing eye [15].   Obstructive sleep apnoea can manifest as noisy snoring,  characteristically crescendoing to a maximum followed by a  period of silence, representing the apnoeic period with a  cyclical restart, or a failure to thrive coupled with daytime  tiredness. If OSA is suspected, an initial overnight pulse  oximetry study can be undertaken, and if this proves to be  suggestive of OSA, a full polysomnogram sleep study should  be performed. This can be combined with formal ICP moni-  toring should there be any concerns about raised ICP. The  active management of established OSA requires intervention  from the multidisciplinary team, and the respiratory/ENT  specialist input is paramount. It is important to establish the  causes of sleep disorder and the level(s) of airway obstruc-  tion so that the most appropriate intervention(s) can be  employed. Further investigations might involve micro-  laryngoscopy to exclude tracheal abnormalities. Imaging  with CT is useful, and interventions should be stepwise with  consideration being given to tonsillectomy and adenoidec-  tomy [16].   In the majority of cases of non-syndromic single-suture  abnormalities, a single intervention for the surgical correc-  tion of the head shape is the norm [4].Whilst there is con-  siderable variation between different units regarding    Fig. 79.3 (3.1-3.17) Case series of metopic synostosis. (3.1—3.3)  Preoperative facial views of patient with metopic synostosis, age  23 months (late presentation), note pointed brow, triangular-shaped  skull and hypertelorism. (3.4—3.6) Preoperative CT scan of the same  patient with metopic synostosis—note it is not our usual practice to  obtain preoperative CT in metopic synostosis; however this was taken  due to the subtle (and late) presentation. (3.7—3.14) Intraoperative  views of fronto-orbital remodelling. (3.7) Frontal bar after removal  prior to remodelling. (3.8) Frontal bar and fontal bones after removal    prior to remodelling. (3.9, 3.10) Frontal bar after remodelling with mid-  line graft to correct hypotelorism. (3.11) Frontal bone osteotomised  ready for remodelling. (3.12—3.14) Final views after fixation—fronto-  orbital remodelling or anterior two-thirds remodelling. Note use of  absorbable plates in load—/tension-bearing areas and absorbable  sutures or stainless steel wires in less critical regions. Bone dust and  bone dust putty (fibrin sealant mixed with bone dust) are used in resul-  tant bone defects to encourage ossification. (3.15—3.17) Postoperative  facial views of patient with metopic synostosis    Fig. 79.4 (4.1-4.12) Case series of unicoronal synostosis. (4.1-4.4)  Preoperative facial views of patient with unicoronal synostosis, patient  aged 31 weeks—left unicoronal synostosis—flattened left brow ante-  rior plagiocephaly when viewed from above and ridging of the involved  left coronal suture. (4.5-4.9) Intraoperative views of asymmetric  fronto-orbital advance. (4.5) Precraniotomy planning—note the fused    left coronal suture. (4.6-4.9) After fixation of the osteotomised seg-  ments—asymmetric fronto-orbital advancement; note onlay bone graft  to left supraorbital region, fixation with absorbable plates and pins as  well as absorbable sutures. (4.10-4.12) Postoperative facial views of  patient with unicoronal synostosis    Fig. 79.5 (5.1-5.13) Case series of Crouzon syndrome. (5.1 and 5.2)  Patient with Crouzon syndrome after initial calvarial remodelling aged  34 weeks. (5.3 and 5.4) Preoperative facial views of same patient aged  5 with Crouzon’s type facies. (5.5—5.7) Postoperative facial views after  Le Fort III distraction osteotomies and static fronto-orbital advance  with the rigid external distractor (RED frame) and internal distractors in  place (day 1 post-op). The use of the internal distractors allows for the  early removal of the external device after the active distraction period,  acting as fixation devices for the retention period. (5.8—5.9) Final post-    operative result immediately after RED frame distractor removal.  (5.10-5.11) Late postoperative result following internal distractor  removal. (5.12 and 5.13) Pre- and mid-distraction CT images of Le Fort  III distraction and static fronto-orbital advance. Note internal distrac-    tors engaging zygoma (pushing Le fort III and external RED frame  pulling midface). It is not our usual practice to obtain a CT mid treat-  ment, but this was carried out due to concerns around a possible CSF  leak. The static fronto-orbital advance is secured with absorbable,  radiolucent, plates, but the multiple pin holes are visible    timing and actual intervention, the Glasgow craniofacial  service protocol is outlined in Table 79.3. See also  Table 79.4 for an outline of the surgical procedures com-  monly carried out and the case series (Figs. 79.2, 79.3,  79.4 and 79.5) for an overview of treatment outcomes.   In the management of the syndromic cases, the treatment has  to be more flexible and problem driven. There is consider-  able variation in the severity and comorbidities in this group  of patients. Overall the aim is to minimise the number of  surgical interventions; however re-synostosis, systemic  problems, corneal exposure, airway obstruction and raised  ICP are much more common in the group [14]. In the absence  of additional pressing clinical issues, the syndromic synosto-  sis cases can be managed as the non-syndromic cases in  terms of the timing and extent of skull surgery.    In this period the management is primarily of observation.  The non-syndromic cases are followed up 6 weeks, 6 months  and | year post-skull vault surgery with growth, particularly  head circumference, development and vision being moni-    tored. A final review is usually undertaken immediately prior  to the child starting school. Some units have a much longer  follow-up period; however we reserve longer follow-up for  the small proportion of patients who encounter ongoing  development problems or symptoms. This protocol should  be modified if there is a less well-developed community-  based health surveillance programme.   minimum of annual reviews. In addition to the parameters  noted above, the development of OSA may be insidious, and  therefore at every review this should be asked about specifi-  cally. Towards the end of this period, consideration can be  given to performing either a midface advancement or hyper-  telorism correction. This decision should be primarily driven  by clinical problems rather than purely aesthetics, though  teasing, bullying and psychological issues can, and should,  play a role in decision-making. The input of child psycholo-  gists is often very helpful in developing a treatment plan and  choosing the optimal timing [17].  During this period it is also important to monitor dental  development and try to optimise routine dental care. In  addition, at some time the patient should be referred for a  full genetic consultation, though the timing of this can be  determined by the needs and desires of the family.  Throughout the care of the patient development, psycho-  logical, educational, physical and speech and language  development should be monitored and intervention initi-  ated when necessary.    4. Frontal bandeau and frontal bone remodelled as  necessary and secured in advanced position.   4. Frontal bandeau remodelled with interposing  bone graft to increase width and flatten midline  prominence.  ¢ Internal resorbable strut plate for strength.  ¢ Resorbable plates bitemporally + bone graft in    4. Frontal bandeau remodelled and secured:  ¢ Internal resorbable strut plate for strength.  ¢ Resorbable plates bitemporally + bone graft in  gap from advancement.  ¢ Brow resecured in midline (resorbable plate/  PDS).  5. Frontal bone remodelling (sectioning and  repositioning + barrel staving).  6. Frontal bone placed and secured (resorbable  plates).    Procedure Access Technical notes Illustrations  Monobloc — Bicoronal stealth incision in the Alice 1. Design mapped out and bur holes made for Illustration 79.11a, b  band region access with matchstick craniotome.  — Anterior dissection (separate pericranial 2. Frontal bone removed (pre—/post-suture).  flap) to superior orbit for access to 3. Access to anterior cranial fossa and superior  frontal bandeau inferiorly (may require orbit.  osteotomies to free supraorbital nerves/ 4. Cuts as per frontal bandeau cuts in anterior  vessels) cranial fossa with direct vision from superior  — Dissection to zygomatic arch bilaterally orbit.  — Intraoral access posterior to hamulus for 5. Cuts at zygomatic arches bilaterally.  pterygomaxillary disjunction 6. Inferior orbital cuts from inferior orbital fissure  — Transconjunctival access to orbital floor laterally and then superiorly to join superior orbit    cuts and medially from inferior orbital fissure  running superiorly to join superior cuts.  7. Osteotomes used to achieve pterygomandibular  disjunction.  8. Smiths/osteotomes to propagate splits.  9. Fixation may be for:  ¢ Static advancement with plates at frontal  bandeau butt joint posterior frontal bone  bilateral zygomatic arches.  ¢ Distraction—Internal distractor at posterior part  of frontal process of zygomatic bone and pins  for the RED frame in the body of the zygoma  and paranasally.  ¢ A combination—Static fronto-orbital  advancement/remodelling (as for FOAR) with  distraction of the Le fort III segment.    — Stealth mapping of dural venous sinuses 3. Positioning of 2/3 distractors and tunnelling  anteriorly to exit either through the wound or  anterior to it.    Facial — Bicoronal stealth incision in the Alice As per monobloc with additional: Illustration 79.14a, b  bipartition/ band region 1. Separation of the nasal septum from the palate  orbital — Anterior dissection (separate pericranial via an intraoral incision.  osteotomies flap) to superior orbit for access to 2. Midline osteotomy of the palate.  frontal bandeau inferiorly (may require 3. Midline removal of bone as required from  osteotomies to free supraorbital nerves/ glabella/nasal region.  vessels) 4. Secure as per monobloc with additional midline   — Intraoral access posterior to hamulus for Box osteotomies of the orbits to achieve orbital  pterygomaxillary disjunction and movement separate from the maxillary movement  anteriorly to separate nasal septum and _ involve the same cuts without disjunction at the Le  split palate fort I level    @Association of Oral and Maxillofacial Surgeons of India ©Association of Oral and Maxillofacial Surgeons of India    Illustration 79.14 (a) Facial bipartition. (b) Box osteotomy to correct hypertelorism    During this period routine monitoring is necessary, and as  the face and dentition develop, attention can be turned to  managing the midface and occlusion. During the transition  from the deciduous to permanent dentition, it is important  to have an orthodontic assessment—so that a definitive  orthodontic/orthognathic plan can be developed. One of  the major factors that may prompt early midface surgery  would be the development of OSA; thus regular question-  ing and targeted investigations at review appointments are  necessary. In considering orthodontics it is important to be  mindful of the fact that repeated courses of orthodontics  will lead to root shortening and also potentially exhaust  the tolerance and cooperation of the patient and his/her  family [18].   In general, the routine correction of hypertelorism can be  safely performed from about the age of 8 years; however this  is determined by the chosen technique (facial bipartition vs  box osteotomy) (illustration 79.14a, b) and whether an early  midface advancement is necessary for the management of  OSA [19]. As with all surgery aimed primarily at improving    facial appearance, the indications, objectives and expecta-  tions of surgery must be discussed at length with the patient  and his/her family and a consensus reached. The input from  specialist child psychologists is often very helpful. The tran-  sition from primary to middle or secondary school is often  traumatic, and interventions before this time can be very  helpful from a psychological perspective, but it needs to be  acknowledged and accepted that further surgery at the com-  pletion of growth may well be necessary [18].    At this stage in development, definitive corrective surgery  (when necessary) should be planned and an integrated orth-  odontic/surgical plan developed. In the syndromic cases,  ongoing monitoring for functional and developmental issues  is required, and as the child matures, the drive and the  responsibility for decision-making will move towards the  patient and away from their parents. Many adolescents at this  stage are tired of multiple hospital appointments and are not  keen on further interventions; in these circumstances it is    important to work with the patient and their family to pro-  vide care but also respect the patient’s wishes and desires. It  is better to postpone treatment rather than have a half com-  pleted course of orthodontics with poor cooperation and the  consequent complications and finally lose the confidence of  the patient.    The planning of comprehensive surgery will need  assessment in the following areas:    It is always best to offer and plan for a total correction in  the first instance. The discussion around further transcranial  surgery is often key to the decision-making. Many patients  and families do not want to undertake any further transcra-  nial surgery, in spite of the significant benefits, particularly  for hypertelorism or dystopia corrections. None the less  these procedures can offer significant improvements in the  final result [19].   For residual skull defects of approximately 2 cm diameter  or larger, it is usual to offer some form of reconstruction; this  could be autologous (usually cranial bone), or alloplastic.  Alloplastic reconstructions may be of a variety of materials  and can be CAD/CAM designed or shaped intraoperatively.  One of the most common residual defects following a fronto-  orbital advancement is a degree of temporal hollowing; this  can be effectively addressed with the use of mouldable  hydroxyapatite synthetic bone material. This technique can  be used to satisfactorily address minor skull irregularities  and defects, and it is also possible to combine this technique  with the use of alloplastic custom-made cranioplasties (e.g.  titanium or PEEK) [20].   The assessment of orbital position is critical to deciding  on what operative procedure to offer. The combination of  hypertelorism and marked maxillary narrowing (particularly  if the upper incisors are crossed), as is often seen in Apert  syndrome, lends itself to correction with a facial bipartition;  this technique can also be used early as the bone cuts do not  result in damage to the dentition. The major drawback of this  technique is that orbital asymmetries cannot be addressed.  The more conventional box osteotomy is used to effect  asymmetric movements, hypertelorism and dystopia correc-  tions. The overall aesthetic outcome is often enhanced with  nasal augmentation and soft tissue surgery, but the final  improvement (particularly in severe hypertelorism cases)   The upper midface can be advanced, either as part of the  bipartition procedure, transcranial Le Fort III (monobloc),  subcranial Le Fort II or Le Fort II. These procedures can be  performed conventionally with bone grafting and fixation  with either absorbable or titanium plates and screws or with  the use of distraction techniques. If distraction is being  utilised, the devices can be a halo-based external device or  buried devices. It is sometimes helpful to combine external  distraction devices with buried devices which facilitate the  early removal of the somewhat cumbersome halo device for  the retention period [21]. In addition to advancement move-  ments, it is possible to incorporate height changes, but rota-  tory movements (e.g. to correct the upper dental midline) are  very difficult unless the symmetry is equal at all facial levels.  Furthermore if the maxillary advancement required has a  significant differential between the upper component and  dental component, it is possible to combine a Le Fort II  (transcranial or subcranial) or a monobloc advance with a  simultaneous Le Fort I osteotomy. This additional level of  movement allows for differential advancements and/or  height changes as well as rotations at the lower level. See  case series in Fig. 79.5 of Crouzon syndrome.   The mandible including the chin should be considered as  one would for conventional orthognathic surgery, but caution  should be exercised in setback procedures as correction of  the occlusion to a retrusive maxilla may worsen or precipi-  tate OSA.   Nasal deformity is best dealt with as close to the end of  treatment as possible; the range of deformity is considerable;  each patient should be treated on their own merits. In cases  with severe deficiency, dorsal augmentation with alloplastic  or autologous material may be necessary, and this can be  refined with nasal tip surgery.   The final phase of surgery is the management of the soft tis-  sues, and again a variety of techniques can be employed to  improve the overall aesthetic result. As well as rhinoplasty tech-  niques, facelifting, brow suspension, eyelid surgery, soft tissue  augmentation with fillers or fat transfer and soft tissue reduction  with direct excision or liposuction all have their place.   See Table 79.2 for an outline of the management of com-  mon clinical problems and Table 79.4 for an outline of surgi-  cal procedures.    1. Wilkie AO, Byren JC, Hurst JA, Jayamohan J, Johnson D,  Knight SJ, et al. Prevalence and complications of single-gene  and chromosomal disorders in craniosynostosis. Pediatrics.  2010;126(2):e39 1-400.   2. Bhadkamkar MA, Albright SB, Wolfswinkel EM, Bollo R,  Buchanan EP. Posterior cranial vault distraction in the treatment    . DiRocco F, Arnaud E, Renier D. Evolution in the frequency of non-    . Mathijssen IM. Guideline for Care of Patients with the diagnoses of    . Cornelissen MJ, Apon I, van der Meulen JJ, Groenenberg IA, Kraan-    van der Est MN, Mathijssen IM, Bonsel GJ, Cohen-Overbeek  TE. Prenatal ultrasound parameters in single-suture craniosynosto-  sis. J Matern Fetal Neonatal Med. 2018 Aug 3;31(15):2050-7.    . Edmond JC, Nischal K, Forbes B, Katowitz W, Costakos D. Update    . Mehta VA, Bettegowda C, Jallo GI, Ahn ES. The evolution of    . Ingraham FD, Alexander E, Matson DD. Clinical studies in cranio-    synostosis: analysis of fifty cases and description of a method of  surgical treatment. Surgery. 1948 Sep 1;24(3):518-41.   Jimenez DF, Barone CM, Cartwright CC, Baker L. Early manage-  ment of craniosynostosis using endoscopic-assisted strip craniecto-  mies and cranial orthotic molding therapy. Pediatrics. 2002;110(1  Pt 1):97-104.   Lauritzen CG, Davis C, Ivarsson A, Sanger C, Hewitt TD. The  evolving role of springs in craniofacial surgery: the first 100 clini-  cal cases. Plast Reconstr Surg. 2008;121(2):545-54.   Khechoyan D, Schook C, Birgfeld CB, Khosla RK, Saltzman B,  Teng CC, Ettinger R, Gruss JS, Ellenbogen R, Hopper RA. Changes  in frontal morphology after single-stage open posterior—middle    vault expansion for sagittal craniosynostosis. Plast Reconstr Surg.  2012 Feb 1;129(2):504—-16.   Beez T, O’kane R, Piper I, Koppel D, Sangra M. Telemetric intra-  cranial pressure monitoring in syndromic craniosynostosis. J  Craniofac Surg. 2016 Jun 1;27(4):1032-4.   Benson ML, Oliverio PJ, Yue NC, Zinreich SJ. Primary cra-  niosynostosis: imaging feature. AJR Am J_ Roentgenol.  1996; 166(3):697—703.   Gonsalez S, Hayward R, Jones B, Lane R. Upper airway obstruc-  tion and raised intracranial pressure in children with craniosynosto-  sis. Eur Respir J. 1997 Feb 1;10(2):367-75.   Broder HL. Using psychological assessment and _ therapeu-  tic strategies to enhance Well-being. Cleft Palate Craniofac J.  2001;38(3):248-54.   Evans RD, Bradford R. The dental and orthodontic management of  craniosynostosis. In: Bux M, editor. The clinical Management of  Craniosynostosis ch 11. London: Mac Keith Press; 2004. p. 211-7.  Gonzalez AM, Elahi M, Barakat K, Yavuzer R, Brinkmann B,  Jackson IT. Hypertelorism: the importance of three-dimensional  imaging and trends in the surgical correction by facial bipartition.  Plast Reconstr Surg. 2005 May 1;115(6):1537-46.   Feroze AH, Walmsley GG, Choudhri O, Lorenz HP, Grant GA,  Edwards MS. Evolution of cranioplasty techniques in neurosurgery:  historical review, pediatric considerations, and current trends. J  Neurosurg. 2015 Oct;123(4): 1098-107.   Schulten A, Lim AA, Bruun RA, Hayes C, Mulliken JB, Padwa  BL. Combined push-pull distraction for correction of syn-  dromic midfacial hypoplasia. J Oral Maxillofac Surg. 2006 Jan  1;64(1):23-30.    Open Access _ This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.  org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropri-  ate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.   The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in  a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.   It is well established that oral cavity cancer develops in a  two-step process and, consequently, that most malignant  ulcers are preceded by a precursor lesions [1]. These lesions  are typically red or white patches referred to altogether in the  2007 WHO consensus statement as the group of potentially  malignant disorders (PMDs) [2] (Table 80.1). Clinical iden-  tification of PMDs offers a window for intervention: elimi-  nating diseased mucosa and exclusion of occult invasive  cancers. This is important from a clinician’s perspective on  several fronts. Firstly, it is important to be able to recognise  high-risk lesions among a multitude of innocent oral condi-  tions that present with similar features. Some conditions  such as oral lichen plans may have a potential for malignant  change, but the condition is so prevalent that it becomes  impractical to monitor every single patient with the disease.  To avoid additional burdens on clinical services, the oral  physician or surgeon needs to make a decision as to which  patients must be kept under review at a specialist centre and  which may be safely referred back for ongoing follow-up in  the community. Among those who are reviewed at a special-  ist practice, ongoing decisions are made at each visit, when  to intervene and to what extent one should be aggressive with  the treatment plan offered. On a second front are the difficul-  ties of recognition of tumour recurrences following treat-  ment. Surgical treatment and radiotherapy change the tissue  appearance and texture irreversibly. Among these patients, it  is known that a proportion would develop either a second  tumour at the site of surgery or a new tumour in a neighbour-  ing area. It is challenging enough to identify precancerous  lesions in nascent tissue, and thus the clinician must be much  more vigilant in recognising potentially cancerous new   Department of Oral and Maxillofacial Surgery, Queen Elizabeth  Hospital, Birmingham, UK    © The Association of Oral and Maxillofacial Surgeons of India 2021    lesions in patients under follow-up posttreatment of head and  neck cancer.   Further to these concerns, we know that premalignant  conditions tend to develop in what is known as field change.  This means that for any subsite within the oral cavity at  which cellular nuclear damage resulted in a PMD (or even  cancer), the adjacent mucosa is almost equally at risk of pro-  ducing additional PMD lesions even if they appear normal to  the naked eye.   Knowledge of the patterns and behaviour of PMDs (pre-  malignant disorder) is thus an essential part of oral medicine  and oral surgery practice.   The commonest PMDs are leukoplakia with an overall  prevalence of 2.9% in the general population [3] and submu-  cous fibrosis with a prevalence of nearly 11% in high-risk  populations [4]. The risk for submucous fibrosis is specific to  populations where paan use is prevalent unlike the risk for  leukoplakia which is universally applicable. Lesions are con-  sidered potentially malignant rather than premalignant.  Clinical behaviour is unpredictable; some lesions remain  stable; others regress, but in up to 30% of cases, oral malig-  nancy is diagnosed within 5 years of follow-up. Cancer may  arise from the lesion itself or at a different subsite within the  oral cavity reflecting the concept of ‘field cancerisation’  explained previously.   It is important to note that a role for primary prevention in  patients with leukoplakia is not confirmed. For example,  smoking is a risk factor for the development of leukoplakia,    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1-15-1346-6_80    but smoking cessation does not necessarily reduce the risk of  developing OCC. There is, however, benefit in screening for  potentially malignant lesions, and this was demonstrated in a  recent review of the US SEER-Medicare database of head and  neck cancer. Yanik et al. [5] reported better treatment and sur-  vival outcomes in patients who developed oral cell carcinoma  whilst under follow-up for a premalignant lesion [5]. This cor-  related with the fact that oral cancers were identified at an ear-  lier stage in this patient cohort. Patients without the benefit of  such close observation tended to present with more developed  or advanced tumour forms. A role for screening patients fol-  lowing treatment for head and neck cancer recurrence is not  known, and thus secondary prevention is not currently known  to be effective. It is likely, however, that the principle of recog-  nising early tumours and potentially malignant lesions would  still result in timely provision of therapy. Table 80.1 enlists  premalignant lesions discussed in this chapter.    Development of a malignancy is a complex multistep pro-  cess resulting from failures in several regulatory cellular  pathways. Dysplasia in oral cancer is usually the first step in  the malignant down spiral. Dysplasia is a descriptive term  used on microscopic assessment. It indicates that the tissue  has accrued a significant population of abnormal cells that  display a pattern of nuclear damage that is known to herald  cancerous behaviour. These changes are summarised in  Table 80.2. Usually but not always, these changes are fol-  lowed by unregulated hyperplasia (cellular multiplication).  The tumour cells have gained autonomy meaning they  escaped nuclear and immune mechanisms that limit excess  growth and prevent accumulation of damaged cells. The final  step is loss of integrity of the basement membrane at the  boundary between mucosa and submucosa; the dysplastic  cells begin to invade into the surrounding tissues or directly  gain access to vascular channels. Each of these steps is con-  trolled by molecular pathways directed by gatekeeper genes  and gene products.   Two cellular or microscopic changes broadly define oral  premalignancy: hyperplasia which results from over activa-  tion of the retinoblastoma pathway and the development of  various degrees of dysplasia due to mutations in the p53   Irregular cell shape and orientation  Increased and abnormal mitoses  Nuclear pleomorphism    gene. In health and normal physiology, genes along the reti-  noblastoma pathway activate transcription factors required  for taking the cells from the indolent G1 to the active S  phase. Overactivation of these genes leads to loss of control  of orderly cell division resulting in epithelial hyperplasia. A  product of the CDKN2A gene, the p16 protein, usually keeps  this stage of cell cycle in check. This protein may become  inactivated either because of a mutation/deletion/epigenetic  slicing of the parent gene CDKN2A or through direct degra-  dation by a viral product, the E7 protein, of the HPV virus  (relevant to the development of oropharyngeal cancer). The  retinoblastoma pathway may also be directly upregulated by  amplification of the Cyclin D1 gene, a proto-oncogene of the  locus 11q13 [6].   With each cell division, there is a probability of errors  arising in the nuclear DNA resulting in a defective daughter  cell. Most errors are corrected during cell division, or the  cells are removed by immune mechanisms. Defective cells  that have escaped these reparative measures may still be sup-  pressed by transcription factors that induce apoptosis.  Apoptosis is triggered through p53, a tumour suppressor pro-  tein. The protein p14 is an alternative reading frame of the  CDKN2A gene responsible for initiating the p53 pathway.  Direct degradation of p53 by the E6 viral protein (HPV-  related cancer) or genetic mutations in the parent gene (in  60% of non HPV cancer) restricts protective physiological  apoptosis leading to a shift in cell population and accumula-  tion of dysplastic cells. The premise behind looking out for  premalignant disorders is that oral mucosa will change  appearance with the onset of dysplastic changes and that the  extent of dysplasia does correlate with malignant potential.  High-grade dysplastic lesions indicate treatment is required  imminently, whereas mild dysplastic lesions may be observed  and are even considered a feature of benign chronic inflam-  mation. Dysplasia is classified according to several grading  systems summarised in Table 80.3, the most common system  in use being the one proposed by the WHO in 2005. Further    genetic changes are involved in progression towards inva-  siveness, but these are not as well defined as these are outside  the scope of the chapter.    Idiopathic leukoplakia is the most common premalignant  disorder. Nearly one in every 10 cases of oral cavity cancer  (OCC) is known to arise in leukoplakia (Fig. 80.1), usually  within 3 months of diagnosis of the lesion [5]. These lesions  are defined as ‘white plaques of questionable risk having  excluded disorders that carry no increased risk for cancer’  [2]. Table 80.4 enlists white lesions without a known malig-  nant potential. These are rare, and thus most persistent white  patches are best treated with suspicion until further  evaluation.   Clinical variants of leukoplakia include homogenous  plaques, nodules, speckled erythroleukoplakia and a distinct  subtype discussed separately: proliferative verrucous sub-  type. Leukoplakia is present in less than 1% of the general  population [5] but with greater prevalence reported among  those older than 75 years of age and tobacco users of all age  groups [7]. Men are twice as much likely to develop leuko-  plakia compared with women. In the Indian subcontinent, in  regions where betel is consumed, prevalence rates approach  5% [8]. The annual risk of malignant transformation is esti-  mated between 1 and 2% [9]. Larger non-homogeneous    lesions, particularly those on the tongue and floor of the  mouth, are associated with the highest conversion rates to  oral squamous cell carcinoma. Table 80.5 lists clinical risk  predictors for malignant transformation.   Tissue biopsy is required to assess the degree of epithelial  dysplasia, an independent and consistently reliable risk fac-  tor for malignant transformation. Liu et al., using a binary  grading of dysplasia, found that patients with high-risk  lesions (moderate/severe dysplasia) eight times as likely to  be diagnosed with oral cancer as those with low-risk (no/  mild dysplasia) lesions [10]. Histological evaluation may  also identify other conditions that are clinically indistin-  guishable from idiopathic leukoplakia such as hyperplastic  candidosis, oral lichen planus variants, lichenoid reactions  and discoid lupus.   Categorisation into high- and low-risk lesions is helpful in  identifying target areas for surgical removal and those that  may be safely observed but closely followed up.   However, in populations with high incidence of oral can-  cer, studies have shown oral leukoplakia as foci of invasive  cancer and have advocated surgical excision of these lesions.   Toluidine blue dye improves visual detection of high-  risk mucosa [11] and helps determine the extent of periph-  eral margins required for complete excision. It is not  established whether surgical intervention reduces the risk  of subsequent cancer, but a resection specimen may upgrade  the histological evaluation or identify areas of occult focal  invasion. Recurrence following surgery is observed in 10%  of cases [12]. Laser surgery is effective in controlling low-  grade leukoplakia, but significantly higher failure rates of  up to 9% were reported in high-grade lesions and erythro-  leukoplakia [13]. Recent reviews have examined photody-  namic therapy as a treatment option particularly helpful in  controlling widespread and multifocal leukoplakia [14].  Partial and complete response rates as high as 70—100%  were reported, but the range of photosensitisers used and  photo-irradiation protocols applied varied greatly between  individual authors.   Medical treatments for oral premalignancy include sys-  temic vitamin A, systemic beta carotene and topical bleomy-  cin. These were shown to control premalignant lesions, but a  2016 Cochrane review concluded that relapse rates were  high and that transformation into oral cancer was not effec-  tively reduced [15].    Proliferative verrucous leukoplakia (PVL) is a distinct and  aggressive form of leukoplakia with one of the highest  known malignant transformation rates. It is typically diag-  nosed in elderly women (4:1 female ration) without a history  of tobacco use [16]. Aetiology is thus largely unknown.  Lesions often start as isolated flat white plaques but gradu-  ally spread to become diffuse and multifocal with a charac-  teristic warty appearance (Fig. 80.2). There typically is no  erosive component. The lesions tend to present on the tongue  or buccal mucosa or well as the alveolar ridge. They can be  mistaken for hyperplastic candidosis or frictional keratosis  particularly in denture wearers. Histological appearance is  dependent on the stage of the disease ranging from benign  hyperkeratosis to dysplastic keratosis merging into verru-  cous carcinoma. Malignant transformation may also happen  simultaneously at multiple foci, and this is one of the clearest  manifestations of the field cancerisation concept introduced  earlier. Verrucous carcinoma is a squamous cancer with well-  differentiated histopathological architecture that displays  very little cellular atypia.   PVL is a lesion that benefits from excision biopsy rather  than an incisional sample (see biopsy discussion below) for  it is estimated that 20% of verrucous lesions, if adequately  sampled, would reveal foci of conventional pattern squa-  mous cell carcinoma. Local control is, however, difficult  with high recurrence rates following surgical excision and  greater malignant transformation rates in excess of 70%  [17]. It is also one of the most difficult lesions to follow up,  requiring multiple biopsies to monitor behaviour over time.    Erythroplastic lesions (Fig. 80.3) are similarly defined to oral  leukoplakia but as red velvety lesions following exclusion of  other named entities. It is a rare disorder with prevalence    between 0.01 and 0.2% but a much higher transformation rate  compared to leukoplakia, reportedly between 51 and 90%  [16]. Clinical appearance tends to follow one of three pat-  terns: the homogenous, granular and speckled types [12].  Most common subsides are the palate, the buccal mucosa and  the floor of the mouth. Lesions are rarely multicentric and  may present a similar clinical appearance to erosive and atro-  phic oral lichen planus, erythema migrans, stomatitis, candi-  dosis, lymphatic malformations and desquamative gingivitis  (e.g. vesiculobullous lesions and gingival lichen planus).  Speckled erythroplakia and leukoplakia most likely refer to  the same disorder with red appearance correlating to high-  risk epithelial dysplasia. Treatment options are surgical exci-  sion, laser excision or evaporation as per leukoplakia with a  lower threshold for application for wide local excision due to  the higher risk of cancer development.    Oral submucous fibrosis is progressive scarring disorder  linked to the use of betel products (paan). Additional risk for  oral squamous cell carcinoma is conferred by the addition of  slaked lime to the betel quid or concurrent use of tobacco.  The active ingredients in paan include arecoline, copper and  polyphenol fragments (flavonols, tannins) which stimulate  an intense acute inflammatory response characterised by a  polymorphic infiltrate and vascular dilatation. This gives  way to a chronic immune response and constrictive vascular  changes that end with obliteration of blood vessels in the  affected region. Over time, this leads to an epithelial to mes-  enchymal transition mediated by TGF-B [18]. Fibroblasts are  activated, and collagen is deposited steadily replacing the  submucous tissues with hyalinised cartilage almost devoid of  cellular components. Several genes are known to associate  with the risk of developing submucous fibrosis including  MMP3 gene promoter region and CYPIAI/CYP2E]1 genes,    but the genetic basis for transformation into squamous cell  carcinoma is not currently defined. Table 80.6 summarised  the histopathological evolution and progression of submu-  cous fibrosis.   Consumption of paan is common in Southeast Asia and  the Western Pacific but is now also seen in Europe and North  America. It is estimated that more than half a billion persons  consume betel worldwide [19]. Early presentation reflects  the early histological picture with non-specific inflammatory  mucosal changes. The diagnosis becomes clearer when early  changes are replaced by the characteristic hypo-vascular  blanched appearance with a fibrous texture although these  changes may be patchy or reticular causing potential confu-  sion with unrelated mucosal changes (e.g. lichen planus). In  general, submucous fibrosis tends to present in young adults  (predominantly males) with worsening trismus (37.2% of  patients), painful dysesthesia (25.9%), excess salivation  (22.5% of patients) and recurrent ulceration. Clinical find-  ings on examination are white patches particularly in the  buccal mucosa (20.8%) and the palate (17.7%) followed by  the floor of mouth and the retromolar trigone [20]. Clinical  signs develop within 3-5 years following commencement of  chewing betel preparations. Patients are 19 times as likely to  develop oral cancer particularly with betel quid containing  tobacco [4]. Malignant transformation rates are reportedly  4-13% [21].   Conservative and medical measures are considered for the  early clinical stages. This includes physiotherapy, immune  modulators steroids and promoters of blood flow such as  pentoxifylline. Many other medical treatments are reported  but none with definitive clinical benefit.   Surgical options are limited and complete excision  unlikely, but surgery is usually indicated for local release of    retromolar or buccal scarring to help relieve trismus. Release  of trismus is usually necessary at the mouth opening of  25 mm and less and is achieved with incisions, local V-Y  flaps and masticator muscle myotomy, resurfacing the defect  with the buccal fat pad or other grafts.    Lichen planus (LP) (Fig. 80.4) is a prevalent inflammatory  much cutaneous disease affecting 5% of the population  worldwide. The pathogenesis is not well understood but is  essentially an autoimmune response to the epidermal basal  cell layer mediated by cytotoxic T cells. Characteristically, T  cells are seen to infiltrate into the lamina propria on micros-  copy and the damaged basal keratinocytes degrade into  apoptotic residues known as civatte bodies (not pathogno-  monic for LP) [22]. Aetiology is unknown, but it is well rec-  ognised that appearances of lichen plans can result from a  hypersensitivity reaction to nonsteroidal anti-inflammatories,  angiotensin-converting enzyme inhibitors and dental amal-  gam. These reactions are more commonly referred to as  lichenoid mucositis. In rare instances, the disease associates  with viral hepatitis (B and C), but in most patients LP, there  is no triggering factor. Stress is thought to be a contributing  factor.   Commonly, oral lichen planus (OLP) presents as reticular  white patterns on the buccal mucosa or the tongue known as  Wickham’s striae. Many varieties and presentations are rec-  ognised such as desquamative gingivitis, plaque form and an  unusual form that presents with vesicular bullae. An erosive  form is also recognised giving the appearance of the high-  risk erythroplakia and mixed red and white lesions [23].  Some authors use the term erosive OLP to refer to the ulcer-  ated type of lesion and erythematous OLP as the commoner  type which affects atrophied buccal mucosa (usually seen    with reticular lesions). Distribution is usually symmetrical, a  feature it shares with discoid lupus.   It is not clear whether oral lichen planus (OLP), a rela-  tively common benign condition, is an independent risk fac-  tor for malignancy. A meta-analysis of 7806 patients  concluded that just over 1% of patients OLP develop oral  cavity cancer [24]. The highest risk subsites were predomi-  nantly the tongue (51%) and the buccal mucosa (32%).  Malignant transformation was three times as likely in females  as it was in men. It is proposed that changes at lower-power  magnification of oral leukoplakia resemble lichen planus or  that lichenoid changes in epithelial dysplasia are common.  Clinically, there is overlap between the clinical appearance  of the various types of OLP and between erythroleukoplakia  and verrucous leukoplakia. A diagnosis of OLP is more  likely in symmetric lesions, but only a biopsy demonstrating  epithelial dysplasia would confirm truly high-risk lesions.  Correlation between malignant change and certain subtypes  of OLP, namely, the erosive and plaque-like forms, has not  been consistent. Interestingly a co-existence with prolifera-  tive verrucous leukoplakia has been noted by several authors  [25, 26].    Candida is present in the oral cavity in between 40 and 60%  of healthy individuals. Association between Candida infec-  tion and cancer is through smoking, an independent risk fac-  tor equally for the development of chronic hyperplastic  candidosis (CHC) and premalignant mucosal lesions. Once  hyperplastic candidosis is established, these lesions manifest  and behave similar to homogeneous or speckled leukoplakia  with 15% risk of progression to epithelial dysplasia [27].  CHC is usually resistant to antifungal therapy, and thus sur-  gery is indicated particularly for well-defined lesions.    Premalignant conditions are a disparate group of rare con-  genital and acquired disorders of immune regulation, inherit-  able genetic instability and infectious diseases. Table 80.7  enlists conditions that associate with mucosal SCC followed  by Table 80.8 which also provides a summary of clinical fea-  tures, site distribution and risk probabilities for conditions  that associate with the cutaneous type of squamous carci-  noma. Reports of malignant transformations are generally  few and data concerning the natural history of OCC limited.  Conditions that rarely associate with oral SCC such as  Plummer- Vinson syndrome are not discussed here.   Oral leukoplakia in 80%  of patients. 40-5%  malignant transformation  into SCC    Verrucous type and  speckled leukoplakia in  tertiary syphilis. Usually  in the lips, tongue or  palate. 3-33% risk of  transformation    Actinic cheilitis Solar radiation Diffuse, atrophic, ulcerative or  keratotic patches in the lower  lip. 6% risk of malignant    Xeroderma Autosomal Cutaneous-type SCC on the  pigmentosum recessive lower lip observed in young  inheritance adults, age < 20 years  Discoid Lupus [30] 1.3-6.5% risk of developing  SCC and BCC with lighter  skin.    A sample of tissue is required whenever a premalignant dis-  order is suspected. Dysplasia cannot be visualised on clini-  cal inspection. It is true that some lesions such as the  speckled red and white lesions are most likely to harbour  dysplastic cells, but it is hard to characterise white patches  as dysplastic or not on clinical examination alone. Most  sites within the oral cavity are accessible for a biopsy under    local anaesthetic. General anaesthetic may well be indicated  in some cases depending on tumour site particularly in the  oropharynx or in patients not compliant with awake proce-  dures. A biopsy may be obtained either by using a scalpel  blade or through a punch biopsy applicator with pre-set  width.   A small amount of local anaesthetic is administered  locally within the site of the lesion for it provides pain relief  and vasoconstriction through the action of an additive.  Concentrations of 1:50,000 to 1:200,000 epinephrine are  used as vasoconstrictor additives typically to lidocaine.  Other vasoconstrictor agents include felypressin typically  combined with prilocaine as a local anaesthetic. Care should  be taken in patients who take anti-platelets agents or antico-  agulant medications. The oral mucosa has a rich blood sup-  ply, and bleeding from small biopsy sites may prove to be  difficult to control.   Excision of the abnormal patch as a whole may be achiev-  able in smaller lesions, but in large and extensive lesions, an  incisional sample is indicated. The site for taking a biopsy in  this case is important. A white lesion may contain within  multiple foci, and a biopsy from a uniform looking area may  miss an area of dysplasia or early invasive cancers. Within a  white lesion, it is advisable to take a biopsy from a speckled  area, an area where there is induration/thickening and an  erosive patch or where there is frank ulceration. When there  is ulceration, then removal of tissue from the centre of the  ulcer may return tissue that is necrotic and hard for the  pathologist to interpret. Thus, it is also advised to take a  biopsy from the margin of the ulcer particularly if the mar-  gin is elevated or everted. A small extension to incorporate  normal looking tissue is helpful to enable the pathologist to  visualise pathological transition into normal background  architecture and pick up subtle changes that may otherwise  be difficult to interpret.   The full thickness of mucosa is required for complete  assessment. Invasiveness is impossible to interpret without  inclusion of the basement membrane in the tissue biopsy.  Traditionally that may not have been crucial for at the high-  est end of the dysplastic spectrum severe dysplasia is also  considered to be at least as intra-epithelial neoplasia and in  most cases surgical excision would be indicated. However,  recent modifications of the TNM classification system and  the work of D’Cruz et al. have highlighted depth of inva-  sion as an independent risk predictor for regional metasta-  sis [31].   Thus a biopsy may not only identify the nature of the  lesion and reveal unexpected invasiveness; it may also deter-  mine the next step in treatment whether surgical excision of  the lesion is enough or whether the threshold for regional  surgery (i.e. a neck dissection) is required as well.   Once the sample is removed, haemostasis is required with  either bipolar diathermy or, in small sites, chemical cautery    with silver nitrate that is useful too. Most biopsy sites lend  themselves to primary closure with a resorbable suture,  whereas particular sites such as the mucosa overlying the  hard palate may be safely left to heal by secondary intent.    Clinical examination of the oral cavity must include active  screening for mucosal changes that are potentially cancer-  ous. This may take place in the primary care setting, in dental  practice, for these lesions are mostly asymptomatic and the  patients may not be aware of their presence. A high index of  suspicion is required for it is well known that although some  lesions associate with known risk factors (e.g. oral submu-  cous fibrosis), many lesions do not (e.g. verrucous leukopla-  kia). Clinical features may be ambiguous with some lesions  that are red, erosive or speckled lending themselves to easier  recognition compared with faint leukoplakia and subtle early  changes in long-standing lichen planus. A low threshold for  biopsy is recommended unless the lesion is demonstrably  consistent with candidosis (i.e. may be clinically wiped off)  or in the case of striated lichen planus that has remained con-  sistent and well defined. Clinical photography is helpful in  establishing objective documentation lesions for it is likely  that the patient would be reviewed by different clinicians  during follow-up. Once identified and histology is character-  ised, then lesions require stratification into high-risk and  low-risk categories in order to determine the long-term plan  for the patients, namely, surgical removal versus clinical  observation, and the appropriate recall intervals for future  follow-up. As discussed above, the treatment options are  diverse and are tailored to the size of the lesion and degree of  epithelial dysplasia. Although surgical removal does not  eliminate the risk of malignant change entirely, early identi-  fication and close follow-up of premalignant lesions offer the  best chance for achievement of good local control if and  when oral cancer develops.    1. Reibel J. Prognosis of Oral pre-malignant lesions: significance of  clinical, histopathological, and molecular biological characteristics.  Crit Rev Oral Biol Med. 2003;14:47-62.   2. Warnakulasuriya S, Johnson NW, van der Waal I. Nomenclature  and classification of potentially malignant disorders of the oral  mucosa. J Oral Pathol Med. 2007;36(10):575-80.   3. Banéczy J, Gintner Z, Dombi C. Tobacco use and oral leukoplakia.  J Dent Educ. 2001;65(4):322-7.   4. Wollina U, Verma SB, Ali FM, Patil K. Oral submucous fibrosis: an  update. Clin Cosmet Investig Dermatol. 2015;8:193—204.   5. Yanik EL, Katki HA, Silverberg MJ, Manos MM, Engels EA,  Chaturvedi AK. Leukoplakia, oral cavity cancer risk, and can-  cer survival in the U.S. elderly. Cancer Prev Res (Phila).  2015;8(9):857-63.    Pitiyage G, Tilakaratne WM, Tavassoli M, Warnakulasuriya  S. Molecular markers in oral epithelial dysplasia: review. J Oral  Pathol Med. 2009;38(10):737-S2.    . Amagasa T. Oral premalignant lesions. Int Clin Oncol. 2011;16:1-4.  . Gupta PC, Mehta FS, Daftary DK, Pindborg JJ, Bhonsle RB,    Jalnawalla PN, et al. Incidence of oral cancer and natural history  of oral precancerous lesions in a 10-year follow-up study of Indian  villagers. Community Dent Oral Epidemiol. 1980;8:283-333.    . Brouns ER, Baart JA, Bloemena E, Karagozoglu H, van der Waal    I. The relevance of uniform reporting in oral leukoplakia: defini-  tion, certainty factor and staging based on experience with 275  patients. Med Oral Patol Oral Cir Bucal. 2012;18(1):e19-26.   Liu W, Wang YF, Zhou HW, Shi P, Zhou ZT, Tang GY. Malignant  transformation of oral leukoplakia: a retrospective cohort study of  218 Chinese patients. BMC Cancer. 2010;10:685.   Chainani-Wu N, Madden E, Cox D, Sroussi H, Epstein J, Silverman  S Jr. Toluidine blue aids in detection of dysplasia and carcinoma in  suspicious oral lesions. Oral Dis. 2015;21(7):879-85.   Lodi G, Porter S. Management of potentially malignant disorders:  evidence and critique. J Oral Pathol Med. 2008;37:63-9.   Thomson PJ, Goodson ML, Cocks K, Turner JE. Interventional  laser surgery for oral potentially malignant disorders: a longitudinal  patient cohort study. Int J Oral Maxillofac Surg. 2017;46(3):337-42.  Gondivkar SM, Gadbail AR, Choudhary MG, Vedpathak PR,  Likhitkar MS. Photodynamic treatment outcomes of potentially-  malignant lesions and malignancies of the head and neck region: A  systematic review. J Investig Clin Dent. 2018;9(1)   Lodi G, Franchini R, Warnakulasuriya S, Varoni E, Sardella A, Kerr  AR, Carrassi A, MacDonald LCI, Worthington HV. Interventions  for treating oral leukoplakia to prevent oral cancer. Cochrane  Database Syst Rev. 2016;7(7):CD001829.   Mortazavi H, Baharvand M, Mehdipour M. Oral potentially malig-  nant disorders: an overview of more than 20 entities. J Dent Res  Dent Clin Dent Prospects. 2014;8(1):6-14.   Munde A, Karle R. Proliferative verrucous leukoplakia: an update.  J Cancer Res Ther. 2016;12(2):469-73.   Hu Y, Jian X, Peng J, Jiang X, Li N, Zhou S. Gene expression pro-  filing of oral submucous fibrosis using oligonucleotide microarray.  Oncol Rep. 2008;20(2):287-94.    Nelson BS, Heischober B. Betel nut: a common drug used by natu-  ralized citizens from India, Far East Asia, and the South Pacific  Islands. Ann Emerg Med. 1999;34(2):238-43.   Pandya S, Chaudhary AK, Singh M, Singh M, Mehrotra  R. Correlation of histopathological diagnosis with habits and  clinical findings in oral submucous fibrosis. Head Neck Oncol.  2009; 1:10.   Yaming P, Urs AB, Saxena A, Zuberi M. Roles of CYPIAI and  CYP2E1 gene polymorphisms in Oral submucous fibrosis. Asian  Pac J Cancer Prev. 2016;17(7):3335—40.   Pranay T, Kumar AS, Chhabra S. Civatte bodies: a diagnostic clue.  Indian J Dermatol. 2013;58(4):327.   Olson MA, Rogers RS 3rd, Bruce AJ. Oral lichen planus. Clin  Dermatol. 2016;34(4):495—504.   Fitzpatrick SG, Hirsch SA, Gordon SC. The malignant transforma-  tion of oral lichen planus and oral lichenoid lesions: a systematic  review. 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Disseminated discoid lupus erythematosus leading to squamous  cell carcinoma. Indian J Dermatol. 2012;57(2):158-61.   D’Cruz AK, Vaish R, Kapre N, Dandekar M, Gupta S, Hawaldar  R, et al. Head and neck disease management group. Elective versus  therapeutic neck dissection in node-negative oral cancer. N Engl J  Med. 2015 Aug 6;373(6):521-9.    Open Access _ This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.  org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropri-  ate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.    The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in    a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.   The incidence of oral and oropharyngeal SCC is on the rise.  Each year approximately 263,000 new cases of oral cancer  are detected worldwide, and 127,000 people die of the dis-  ease [1]. In India it is the third most common cancer and  accounts for almost 40% of deaths. Among men it is the sec-  ond most common site, and in women it is the fourth in India  [2]. In 2012, the incidence rate for male was 10.1/1,00,000  and for female 4.3/1,00,000 [3].   Oral carcinoma commonly called as the oral squamous cell  carcinoma (OSCC) occurs as an ulceroproliferative lesion of  the oral mucosa affecting any site starting from the lips to the  oropharynx. The commonest sites are gingivobuccal sulcus  of mandible followed by the tongue and floor of the mouth.  It should be understood that Indian cancer is much different  to other parts of the world. The habit of the tobacco chewing  (smokeless tobacco) and pan masala, i.e., a mixture of the  tobacco, betel nut, and unknown chemicals used for the color  and flavors, is the commonest cause. Classical Indian cancer  is the gingivobuccal sulcus (GBS) of the mandible due to the    Electronic Supplementary Material The online version of this chap-  ter (https://doi.org/10.1007/978-98 1-15-1346-6_81) contains supple-  mentary material, which is available to authorized users.    V. Deshmukh (541)  Maxillofacial and Microvascular Surgeon, Deshmukh Institute of  Maxillofacial Surgery and Research Centre, Aurangabad, India    Department of Dentistry and Maxillofacial Surgery, JITU’S Indian  Institute of Medical Sciences, Maharashtra, Jalna, India   Head and Neck Surgeon (OMFS), Ninewells Hospital and Dundee  University Medical School, Dundee, UK    © The Association of Oral and Maxillofacial Surgeons of India 2021    placement and holding of the tobacco-lime mixture, in the  area. Over the last three decades, pan masala has become  popular, due to the easy availability in pre-mixed packed.  This maybe chewed or kept in the oral cavity, i.e., GBS,  which leads to continuous action of the contents on the oral  mucosa. The constant irritation leads to fibrosis and with  time results in submucous fibrosis.    Etiology of oral SCC is multifactorial. Local irritants con-  tribute significantly to the conversion of a premalignant pro-  cess to invasive carcinoma. Damage to the epithelial layer  followed by the basement membrane and submucosa sec-  ondary to chemical and mechanical injury leads to fibrosis of  the mucous membrane.    1. Tobacco consumption—All forms of tobacco smoke as  well as smokeless have carcinogenic potential. Evidence  for smokeless tobacco causing oral and pharyngeal can-  cer was evaluated and confirmed [4]. India is the third  largest producer and consumer of smoked and smokeless  forms of tobacco. Tobacco-related cancers account for  nearly 50% of all cancers among men and 25% of all can-  cers among women with the burden of tobacco-related  cancers in 2001 estimated to be nearly 0.33 million cases  annually. It has been predicted that an incidence of seven-  fold increase in tobacco-related cancer is expected  between 1995 and 2025 resulting in an increase by 220%  of cancer deaths simply related to tobacco use [5]. In  India chewable tobacco is consumed in various forms.  The traditional form is called the pan (Figs. 81.1, 81.2  and 81.3). Local form of smoking tobacco is called as  bidi, which is a crude form of cigarette. This is consid-  ered to be more carcinogenic. It commonly causes carci-  noma of the palate, oropharynx, and larynx.    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1 -15-1346-6_81    Fig. 81.1 Betel nut (areca nut). Various forms. Raw red in color and  roasted white in color. It is broken in pieces with a special cutting  device. Pieces are chewed with tobacco-lime mixture or with betel quid    Fig. 81.2 Pan masala (gutkha) pouches. Ready to eat mixture of  tobacco, betel nut, lime, catechu, and unknown chemical coloring and  flavoring agents    2. Alcohol—Alcohol is considered to be causally associated  with oral cancer. As heavy alcohol drinkers are frequently  heavy smokers as well, a synergistic effect with cigarette  smoking is implicated in oral cancer [6-8]. Excess alco-  hol consumption is associated with nutritional deficien-  cies. This acts as an aggravating factor.   3. Betel nut chewing (areca nut)—Chronic chewing of the  betel nut leads to abnormal fibrosis of the oral-pharyngeal  areas. Betel nut is the endosperm of the fruit of Areca  catechu. It is consumed in various forms. It is used fresh    Fig.81.3  Pan-betel quid. Betel leaf coated with lime-catechu-flavored  tobacco-betel nut. It is rolled, wrapped, and pinned with clove. Most  commonly chewed in Indian subcontinent    or dried or may be cured before use by boiling, baking, or  roasting. The abrasive mechanical property causes attri-  tion of teeth and physical damage to the mucosa. This  sandpaper action makes the mucosa more susceptible to  the chemical properties of beetle nut. In India alone 38  different combinations of areca nut with tobacco have  been documented (Fig. 81.1). The number of patients  with a pan masala chewing habit (68.0%) was higher than  the number of patients with betel nut (17.4%) or betel  quid chewing habits (14.6%). The chewing of pan masala  is associated with earlier presentation of oral submucous  fibrosis (OSMF) as compared to betel nut chewing [9].  Pan masala (Fig. 81.2) is the artificial mixture available in  small pouches having contents of tobacco, betel nut,  spices, coloring and flavoring agents, preservatives, as  well as unspecified agents. This has proven to be highly  carcinogenic. Consumption of this mixtures leads to  OSMEF which is a precancerous condition. Development  of precancerous lesions like leukoplakia in preexisting  fibrosis potentiates carcinoma conversion. Betel nut is  also consumed with a pan (Fig. 81.3) a freshly prepared  mixture on the betel leaf with tobacco, slaked lime, cate-  chu, and clove. This is chewed over a longer time and  remains in contact with oral mucosa causing mechanical  and chemical irritation. The important flavonoid compo-  nents in areca nut are tannins and catechins. These alka-  loids undergo nitrosation and give rise to N-nitrosamine  which might have cytotoxic effect on cells [10].   4. Nutritional deficiencies—Dietary deficiencies of vitamin  A, folate, riboflavin, iodine, and iron add to the risk of  cancer. High dietary fiber; vitamins C, E, and A; and sele-  nium offer protection against cancer [11, 12].    5. Poor oral hygiene and traumatic injury of dental ori-  gin—Poor oral hygiene is often associated with  gingivoperiodontal infections raising bacterial colony  count leading to a constant inflammatory response. This  together with traumatic tooth injury can lead to a carcino-  genic effect.   6. Viral infections—The role of human papillomavirus  (HPV) in pharyngeal cancer is well established. However  its effect on the oral cavity is still being researched.  Globally, HPV infection is relatively more common in  OSCC patients [12].    Precancerous situations can be broadly divided into precan-  cerous conditions and precancerous lesions. Precancerous  condition’s most commonly seen in India are oral submu-  cous fibrosis (OSMF) and oral lichen planus. Precancerous  conditions can be associated with the precancerous lesions  (please also see Chap. 80 on premalignant lesions and  conditions).    Precancerous conditions make every part of the oral cavity  susceptible to cancer conversion as is seen in oral submucous  fibrosis (OSMF). The phenomenon simulates field cancer-  ization. Development of a second primary despite adequate  treatment of the first is common. Sometimes two primaries at  distant anatomical sites are noted in extensive long-standing  OSMF.    Oral submucous fibrosis is a chronic insidious disease of the  oral mucosa characterized by loss of mucosal elasticity and  excessive fibrosis (Figs. 81.4, 81.5 81.6 and 81.7). It is  always associated with juxta-epithelial inflammation and  progressive hyalinization of lamina propria [13]. Oral sub-  mucous fibrosis (OSMF) is predominantly seen among betel  quid chewers and pan masala chewers in India. OSMF gen-  erally starts at the RMT (retromolar trigone), anterior faucial  pillars, and the adjoining area of the soft palate. It extends to  involve the buccal mucosa, commissure, lips, and rima oris.  Resulting trismus is due to mucosal and muscle fibrosis in  the masseter and pterygoids. Figures 81.8 and 81.9 shows  the traumatic ulcers caused in buccal mucosa and RMT area  in OSME cases mainly due to the limited mouth opening and  fibrosis. In such cases early dental intervention or extractions    Fig. 81.4 OSMF (oral submucous fibrosis). Note fibrosis affecting  RMT, faucial pillars, buccal mucosa, as well as rima oris    Fig. 81.5 OSMF (oral submucous fibrosis). Note fibrosis affecting  RMT, faucial pillars    Fig. 81.6 OSMF (oral submucous fibrosis). Note fibrosis affecting  lower lip and blanching of mucosa. Note pale nails due to anemia    may be delayed due to the difficulty in access to the posterior  teeth due to trismus. Such chronic traumatic ulceration may  undergo malignant change as seen in Fig. 81.10.   Time and constant irritation lead to inflammation with mucosal  atrophy. It can thus be considered that induction of oral muco-  sal inflammation by betel quid is a critical event in the patho-  genesis of OSMF. Cytokines like interleukin-6 (IL-6), tumor  necrosis factor (TNF), interferon-a (INF-a), and growth factors  like TGF-b are synthesized at the site of inflammation.   TGF-b1 is a key regulator of extracellular matrix (ECM)  assembly and remodeling. TGF-b1 increases collagen pro-  duction and decreases its degradation [14]. OSMF has char-  acteristic clinical presentation depending on the stage of the  disease. The majority of patients have intolerance to spicy  food, roughness of oral mucosa, and varying degrees of dif-  ficulty in opening the mouth.   OSMF is a well-recognized potentially premalignant con-  dition of the oral cavity. The transformation rate is as high as  7.6% over a period of 10 years [15]. In this group, primary  malignancy develops in the buccal mucosa extending to  involve the retromolar trigone. This is unique in the context    Fig. 81.10 Malignant transformation in posterior buccal mucosa in a  case of OSMF, accompanied by chronic trauma form tooth    of the Indian subcontinent, as pure tobacco chewing habit  has decreased and is replaced by the gutkha chewing habit.  Tobacco-lime preparation used to be kept in the GBS or the  floor of the mouth for longer period. This led to leukoplakia  and/or erythroplakia, followed by malignant transformation.  The current preparation is not constantly placed in the GBS  but chewed for long time and swallowed. The chemical effect  leads to OSMF and field concretization.    Oral lichen planus (OLP) tends to often present bilaterally as  white striae on the buccal mucosa. Any mucosal site in the  mouth may be involved. Other sites, in decreasing order of    frequency, may include the tongue, lips, gingivae, floor of  the mouth, and very rarely palate [16].   Six clinical forms of oral lichen planus are recognized [17]:  reticular, erosive/ulcerative, papular, plaque-like, atrophic, and  bullous. Atrophic/erosive lichen planus is associated with a  risk of cancerous transformation [18]. Patients with OLP tend  to be monitored closely to detect any potential change early.   The rate of malignant transformation in individual studies  ranged from 0 to 3.5%. The overall rate of transformation  was 1.09% for OLP.    Precancerous lesion is a pathology of the oral mucosa which  has a tendency to transform into the squamous cell carci-  noma. The commonly prevalent lesions are leukoplakia  erythroplakia, carcinoma in situ, and smoker’s palate.    Diagnosis of oral squamous cell carcinoma is not a challeng-  ing task except in the cases of an unknown primary. History  of risk factors, classic clinical appearance of an indurated  ulcer, involvement of lymph nodes, and destruction of bone  are common features in advanced disease.    Oral squamous cell carcinoma often presents as an indurated  ulcer, exophytic growth, indurated non-ulcerative patch  (endophytic), or a combination of the above appearances.  Figures 81.11, 81.12, 81.13, 81.14, 81.15, 81.16, 81.17, and  81.18 shows the various clinical presentation of SCC in  tongue. Fig. 81.19 shows multiple primary tumors arising in  case of OSMF.   Important parameters to be recorded at the primary site in  clinical examination are site of the tumor; size; extension to  involve adjacent structures like the skin, muscles, bone of  maxilla and/or mandible, and skull base; and extensions into  compartments such as the paranasal sinuses, nasal cavity,  orbit, pterygoid space, masticatory compartment, and infra-  temporal fossa. Regional spread to the lymph node basin in  the neck needs clinical and radiologic correlation. Evaluation  of distant metastasis to lungs and bones forms a part of the  staging process.    4,  i =  @©Association of Oral and Maxillofacial Surgeons of India    . 2 - Oe  ©Association of Oral and Maxillofacial Surgeons of India    The minimum radiologic investigation for the primary site  and neck should include imaging from the skull base to the  clavicle. Staging of the chest is to detect both metastatic dis-  ease and synchronous tumors. MRI and/or CT with contrast  is considered to be the gold standard. In poorer socioeco-  nomic background, one could consider ultrasound scan of  the neck as a staging modality. This will however not adhere  to the current international guidelines. In our units the mini-  mum standard is a MRI of the neck (including the primary)  and CT chest. A double-contrast CT of the neck is as valu-  able as a MRI. Radiologic examination provides a greater  accuracy in the staging process. Prognosticators such as  depth of invasion and extracapsular spread in lymph nodes  can be studied with good accuracy.   Where there is involvement of bone, a MRI and CT will    PET-CT-SCC—  Contralateral neck metastasis,  at IIA, of second primary in  Lt. Maxilla    better information on cortical erosion. In addition a thin slice  CT helps in 3D planning prior to free flap reconstruction.   The role of a PET-CT is limited. Its primary indication is  to detect an unknown primary prior to targeted biopsy. A fur-  ther role for the PET-CT is in post-radiotherapy evaluation of  the neck (Fig. 81.20).   MRI scans offer better accuracy of soft tissue extension of  tumor. Studying fat planes between muscle groups allows for  compartment resections in T4 tumors.    Incisional biopsy is the gold standard in the diagnosis of squa-  mous cell carcinoma. FNAC is used for the detection of lymph  node metastasis. However with the increased accuracy in MRI    and USS reporting, this modality is used less. Biopsy tissue  should be taken from the most indurated portion of the tumor.  Taking a biopsy from the summit or the center of an ulcer may  yield a false-negative result. Scalpel, punch, and low-voltage  electrocautery are all good options. Minimum size of the sam-  pled tissue should be ideally 6 mm in all three dimensions.  Mapping biopsy from multiple sites may be required at times  to evaluate the extent of involvement and to prevent a false-  negative result. This is especially the case when a tumor devel-  ops in the background of a premalignant lesion.   Deep biopsy is required to get estimation on the depth of  invasion (DOI). In cases of exophytic lesions, tumor thick-  ness may cause difficulty in getting deeper tissue; in such  cases tumor margin area can be chosen. In order to obtain a  good-quality oral biopsy, the clinician should avoid crushing  the sample with the tissue-holding forceps, infiltrating anes-    thetic solution within the lesion, using an insufficient volume  of fixing solution and taking insufficient amount of tissue in  extension and depth. The specimen should be handled gen-  tly, avoiding any crushing, and introduced in the fixing solu-  tion such as 10% formalin.   In inaccessible areas, due to the site of tumor or reduced  mouth opening, it is good practice to carry out an examina-  tion under anesthesia to evaluate the extent of the tumor.  This also provides an opportunity for the lesion to be accu-  rately biopsied in a more controlled environment of  theaters.    Pathologist is expected to report on the tumor grade—well-  differentiated squamous cell carcinoma, Grade 1; moder-  ately differentiated squamous cell carcinoma, Grade 2; or  poorly differentiated squamous cell carcinoma, Grade 3.  Well-differentiated tumors resemble normal squamous epi-  thelium to a large degree (Fig. 81.21), poorly differentiated  tumors exhibiting little or no histologic traits of the squa-  mous phenotype, and moderately differentiated tumors hav-  ing an intermediate morphology between the two ends of the  spectrum. Higher grades have strong potential for recurrence  and lymph node metastasis [19].   Several prognostic indicators have consistently demon-  strated a correlation with disease-specific survival, local and  regional recurrence, and lymph node metastasis in numerous  single or multicenter studies. The prognosticators are depth  of invasion (DOJ), pattern of invasion (POD, perineural inva-  sion (PNJ), lymphovascular invasion (LVI), and extranodal  extension (ENE).    It is important to differentiate between depth of invasion and  tumor thickness. The DOI is a more predictable prognostica-    tor compared to the latter. It is known that exophytic tumors  (verrucous carcinomas being the prototype) or predomi-  nantly exophytic tumors have a good prognosis, whereas  endophytic or deeply infiltrating tumors are aggressive [20].  Depth of invasion (DOD) is an important independent factor  in prognosis with strong effect on disease-free survival and  overall survival, correlating with propensity for nodal spread  better than tumor size in oral cancer [21-25]. In the floor of  the mouth, 1-cm-wide tumor infiltrating at 0.7 cm depth will  likely have a worse outcome and carries a higher risk of neck  metastasis than a 2-cm-wide tumor with microinvasion or  superficial invasion (e.g., less than 2 mm in thickness)  [26-28].    Pattern of tumor invasion is an important prognostic factor.  Tumor interface abutting deeper tissues has better prognostic  value as compared to multiple tumor satellites into the deeper  tissues [20].    PNI presence is a soft indicator for local recurrence and  decreased survival. Multiple studies have shown conflicting  results [29]. However it is one of the most important predic-  tors of neck metastasis [30] alongside DOI. PNI increases  the rate of occult metastasis [31].    Histopathological presence of lymphovascular invasion has  poorer prognostic outcome. The presence of LVI is associ-  ated with nodal spread or occult metastases [23, 32-34].  Literature review has conflicting evidence regarding the  importance of LVI.    It is common to see OSCC of GBS and retromolar trigone  (RMT) invade the adjoining mandible, maxilla, and ptery-  goid column. This upstages the tumor to a T4.   The increased risk of local recurrence can be attributed to  two factors—tumor character and margin status following  resection. Invasion into the pterygoid spaces makes surgical  resection difficult. Close margin is expected in these  advanced tumors.   Mandible infiltration can be of periosteal fixation, cortical  erosion, or medullary invasion. Deeper invasion has poor  prognosis [35] (Fig. 81.22).    A positive neck node is the single most important prognosti-  cator for disease-free survival at 5 years. Size, number of  levels involved, fixation to adjacent structures, and extranodal  extensions (ENE) are of significance in lymph node assess-  ment of the neck.   In a NO neck, the pickup rate of a sub-centimeter positive  node is less than 50% on clinical examination alone. Use of  radiologic examination increases the pickup rate to 90%. A  staging neck dissection is the only modality that has a pickup  rate greater than 98% [36-38].   A well-lateralized tumor often spreads to the ipsilateral  neck. In 5% of patients, the first echelon can be the con-  tralateral neck. Tongue cancers have the propensity for  skip metastasis and contralateral spread. For all other  regions of the oral cavity, the first echelon spread is at  level I/II.   Depending on the literature one reads, the specificity and  sensitivity between MRI and CT are confusing. The authors  recommend that the radiologist choose the modality he has  the greatest confidence in reporting. Ultrasound scan as a  screening tool is useful in the outpatient setting.   Radiologic signs of nodal involvement are increases in  size of the lymph node, obliteration of the fatty hilum,  increased vascularity, an ill-defined outline, and intranodal  necrosis. Ten millimeters or more in an axial section are con-  sidered positive for nodal involvement in the neck. However,  false-positive or false-negative results of 15-20% are noted  in the literature [39, 40].    Distant metastasis needs to be suspected in lungs and verte-  brae. Evaluation is done by CT alone or a PET-CT scan.    Cancer staging can be divided into a clinical stage and a  pathologic stage. In the TNM (Tumor, Node, and Metastasis)  system, clinical stage and pathologic stage are denoted by a  small ‘“‘c” or “‘p” before the stage (e.g., cCT3N1MO or pT2N0).  This staging system is used for most forms of cancer.  Accurate staging is critical as treatment is often based on  clinical and radiologic stage.   Currently AJCC eighth Edition is used; this includes both  the depth of primary tumor invasion and extracapsular exten-  sion of lymph node metastases. The AJCC eighth Edition  OSCC staging system showed improved disease-free sur-  vival discrimination between overall stages and between T  categories, while AJCC seventh Edition did not [19].   T1l—Tumor < 2 cm in greatest dimension, < 5 mm depth of  invasion (DOI not tumor thickness).   T2—Tumor < 2 cm with DOI > 5 mm or tumor > 2 cm and  <4 cm with DOI < 10 mm.   T3—Tumor > 2 cm and < 4cm with DOI > 10 mm or tumor  >4cm with DOI < 10 mm.    Lip: tumor invades through cortical bone or involves the  inferior alveolar nerve, floor of the mouth, or skin of the face  (.e., chin or nose).   Oral cavity: tumor invades adjacent structures only (e.g.,  through cortical bone of the mandible or maxilla, or involves  the maxillary sinus or skin of the face). Note: Superficial ero-  sion of bone/tooth socket (alone) by a gingival primary is not  sufficient to classify a tumor as T4.   T4b—Very advanced local disease. Tumor invades masti-  cator space, pterygoid plates, or skull base and/or encases  internal carotid artery.   N1—Metastasis in a single ipsilateral lymph node, <  3 cm in greatest dimension and ENE .   N2—Metastasis in a single ipsilateral lymph node, > 3 cm  but <6 cm in greatest dimension and ENE ; or mets in  multiple ipsilateral lymph nodes, < 6 cm in greatest dimen-    Table 81.1 AJCC prognostic staging groups according to the eighth  AJCC edition    Clinical group a N M  0 Tis NO MO  I Tl NO MO  II T2 NO MO  Il ils) NO MO  T1 T2713 Nl MO  IVA T4a NO MO  T1T2T3T4a N1, N2 MO  IVB T4b Any N MO  Any T N3 MO  IVC Any T Any N M1    sion and ENE ; or mets in bilateral or contralateral lymph  nodes, < 6 cm in greatest dimension and ENE .  N2a—Metastasis in single ipsilateral lymph node >3 cm  but <6 cm in greatest dimension and ENE .  N2b—Metastasis in multiple ipsilateral lymph nodes  <6 cm in greatest dimension and ENE .  N2c—Metastasis in bilateral or contralateral lymph nodes  <6 cm in greatest dimension and ENE .   N3—Metastasis in a lymph node >6 cm in greatest dimen-  sion and ENE  or metastasis in any lymph node(s) with  clinically overt ENE .    81.11 Treatment Planning  for the Management of Head  and Neck Malignancy    The management of head and neck cancer has undergone a  sea change since the 1980s. The most important change that  has been to the benefit of both patients and clinicians is the  emphasis on evidence-based practice, and this has led to the  development of the multidisciplinary team (MDT) or the  tumor board as it is also known as.   In the more recent past, a new thought process is the prac-  tice of realistic medicine. The emphasis is on a more person-  alized approach to patient care and changing our style to    shared decision-making. This is an approach that has been  rolled out across Scotland.    The key questions to be asked are:  1. Is this test, treatment, or procedure really needed?  2. What are the potential risks and benefits?  3. What are the potential side effects?  4. Are there alternative simpler, safer treatment options?  5. What would happen if one did nothing?    The beginning of planning treatment starts on the receipt of a  referral or patients’ attendance. Patients with a history of a neck  or salivary gland lump, non-healing ulcer of the oral cavity,  bleeding, pain refractory to analgesia, hoarseness, and dyspha-  gia are seen in the clinic within 2 weeks. Clinical examination  should include the examination of the tongue base, tonsils, lar-  ynx, and nasopharynx with flexible nasoendoscope.   Developing a one-stop clinic helps in avoiding delays,  and this has a significant impact on patients’ psychological  well-being. The one-stop clinic includes a biopsy on the  same day for visible lesions and an ultrasound-guided core  biopsy of neck lumps. The results of these preliminary inves-  tigations should be available in a week, setting up for a sec-  ond meeting.    The second meeting or breaking bad news is perhaps the  most important consultation in treatment planning. Patients  are invited to attend the clinic with members of their family.  Consultation is held in a quiet atmosphere in the presence of  a clinical nurse specialist. It is important to be factual and  honest. Unrealistic expectations should not be given. One  must also bear in mind the impact the diagnosis will have on  patients and their families. Empathy is very important. A  good rapport with the patient and their family is invaluable.    a MRI and/or CT neck and CT chest. The rationale for stag-  ing is localization of the tumor and detection of regional and    distant lymph node metastases. This has an importance in  both the extent of therapeutic intervention and the disease-  specific survival.    The localization of the primary tumor helps in the decision-  making regarding the resectability of the lesion with clear  margins. Tumor resection with a RI margin is considered a  futile procedure, and at the best it is palliative and at its worst  just a “big biopsy.” Anatomical areas of interest in localiza-  tion are the skull base with particular interest to the carotid  canal, involvement of the infratemporal fossa, the extent into  the orbit, and in the case of tongue tumors proximity to the  tongue base and larynx. Involvement of any of the above  structure carries a very high risk of a positive or close mar-  gins resulting in increased risk of recurrence. Adjuvant treat-  ment would then be inevitable. Functional outcomes are  poorer.   MRI of the soft tissues is our preference for localization  of the tumor as it helps in planning anatomic resection by  determining the depth of infiltration. This can be in the form  of compartment resection—medial masticatory compart-  ment resection for retromolar, soft palate, and posterior  tongue tumors. Anatomical resections in tongue tumors uses  muscle planes to identify margins and vascularity of the  remainder tongue. The muscle groups most important to this  are the mylohyoid, styloglossus, and stylohyoid. With tumors  extending to the infratemporal fossa and skull base, a key  landmark is the styloid. Prestyloid resections are considered  straightforward, and a RO margin is to be expected. Tumors  in the poststyloid space carry the risk of a close margin.   Tumors involving the mandible and maxilla, in our prac-  tice, have a CT and MRI. The MRI helps in determination of  matrow signal change and gives an aid to planning resection  margins. The CT has a two fold advantage. CT helps localize  cortical breach and complements the MRI in planning resec-  tion. It has also the added advantage of obtaining 3D models  which helps in planning bone reconstruction with a free flap.   For malignancies of the salivary glands, our first line of  investigation remains an USS-guided core biopsy followed  by a full staging of the neck and chest with MRI and CT,  respectively. Tumors of the skull base and infratemporal  fossa have both MRI and CT for localization of the primary.   For patients with suspected recurrence, especially under a  free tissue flap transfer, the preferred modality is a  PET-CT. PET-CT allows for a functional evaluation of the  suspect area. In areas of previous surgery, the MRI has higher  false-positive rates due to loss of fat planes and the inability  to differentiate from scarification. A double-contrast CT scan  may give better definition of a recurrence; however both  specificity and sensitivity are low. The CT may give better    spatial resolution. However false-negative results are high in  glottic tumors and in mucosal disease with superficial spread  with CT.   The role of PET-CT in our practice is limited to neck  lumps with unknown primary, small malignancies and in  recurrent SCC. The major drawback for a PET-CT is poor  anatomical depiction. Anatomical resection is not possible  with a PET-CT alone. PET-CT adds little value in patients  who have had recent surgery, i.e., biopsy. This invariably  gives rise to a hot spot in inflamed tissue. However, it is more  sensitive than CT and MRI in detecting small malignancy. In  more than 30% of cases, the PET-CT picks up malignancy  not identified by other modalities, and the majority of these  are at the tongue base and supraglottic space.   Direct evaluation by examination under anesthesia and  pan endoscopy provides probably the most accurate assess-  ment for localization and planning surgery.    There are numerous papers regarding the sensitivity and  specificity of different evaluation techniques—clinical  examination, duplex ultrasound scan, CT scan, MRI, and  PET. It is agreed by all that clinical examination of the neck  provides the least reliable results of all and an adjunct inves-  tigation is necessary. It is the opinion of the authors that both  CT and MRI give equally reliable results. The decision to  which modality suits an individual team the best is reliant on  the expertise of the head and neck radiologist in reporting the  scans. In our own clinical practice, we feel that the MRI scan  provides a good diagnostic value for staging the neck. In T1  tumors where there is a NO neck clinically and radiologi-  cally, the evidence for staging neck dissection is limited. In  cases where the MRI is equivocal, an USS with a FNAC (fine  needle aspiration cytology) may be indicated. The USS  would evaluate the lymph node for size criteria, presence of  necrosis, and the absence of normal hilum. Lymph nodes that  are rounded and greater than 1 cm in the neck are regarded to  be pathologic until proven otherwise.   The role of USS should not be easily dismissed with the  advent of cross-sectional imaging. The USS has many advan-  tages. The spatial resolution of a good USS is better than that  of a CT or MRI. Taking account of shape, contour, echo-  genicity, grouping, internal architecture, necrosis, and pat-  tern of Doppler vascularity enhances the accuracy of US for  nodal metastases to greater than 90%.   The USS is a cheap and quick modality that can be used.  There is no radiation exposure. Its use as a surveillance scans  cannot be surpassed in today’s economic constraints. The  one major drawback we have noted in our practice is that its  sensitivity and specificity are highly operator dependent. It  cannot detect retropharyngeal, retrotracheal, and mediastinal    lymphadenopathy. In these instances a CT or MRI gives bet-  ter information.   PET-CT has a limited role in the staging of the neck.  PET-CT is a useful tool to look at post-chemoradiation treat-  ment response and to evaluate the neck following radiother-  apy with residual neck mass. In the head and neck,  misregistration of PET to CT can cause difficulty in report-  ing and increase false-positive results.    The presence of metastatic disease to the neck is an impor-  tant prognostic factor for disease-free survival in head and  neck cancer. Recent papers by Anil D Cruz et al. have shown  that patients who had an elective neck dissection fared much  better than those on the watchful waiting strategy in both T1  and T2 tumors [29].   Sentinel node biopsy relies on the fact that metastases to  the regional lymph nodes follow a predictive pattern in most  cases. Migration of cancer cells is often to the first echelon  node. It is therefore predicted that if the first echelon node is  negative, the more distal node is unlikely to have cancer cell  migration. Validation studies involving elective neck dissec-  tion have shown that there is 95% detection rate in sentinel  nodes. The first echelon node in most oral cancers is at level  I or level II. In a well-lateralized tumor, the first echelon  node more often than not is on the ipsilateral side.   2. To assess the need for bilateral neck dissection in tumors  close to or just crossing the midline.   3. To clarify the need for contralateral neck dissection in  large tumors.    Proponents of SLN biopsy claim the following advan-  tages: reduces the morbidity of elective neck dissection,  more accurate staging of the neck, and better prediction  in those who have an unpredictable pattern of metastatic  disease, therefore guides decision-making, helps identify  skip metastases and micrometastases, and saves time and  expense.   It is the opinion of the authors that sentinel node biopsy is  a very good adjunct. Recent meta-analysis and systematic  reviews suggest that high sensitivity, negative predictive value,  and accuracy of SNB make this a valid diagnostic tool. NICE  (National Institute of Clinical Excellence) guidelines recom-  mend that a SLNB should be offered to all patients with T1  and T2 tumors with a node-negative neck. A word of caution,  however, for T1 and T2 tumors with a tumor thickness greater  than 5 mm, an elective neck dissection may still be indicated.    Following completion of all diagnostic requisites, the find-  ings are discussed at the weekly MDT or the tumor board  meeting. The MDT has a core group of clinicians and  healthcare professionals. The MDT comprises of maxil-  lofacial surgeons, ENT surgeons, oncologist, speech and  language therapist (SALT), dietician, clinical nurse spe-  cialist (CNS), head and neck radiologist, head and neck  pathologist, restorative dentist, and cancer audit officer to  collect data. We have two clinicians from each of the sub-  specialties at our MDT. The MDT should not be regarded  as a forum to advance individual pride or agenda. This is a  group that helps balance evidence base in the management  of patients and makes a realistic recommendation of treat-  ment strategy.   The responsibility of the MDT is to protect and facilitate  the patients’ pathway through cancer treatment. The first and  foremost recommendation made by the MDT is the treat-  ment intent—curative or palliative. This is followed by the  treatment strategy—surgery or radiotherapy + chemotherapy  (Refer Chap. 84 to read about Adjunctive therapy in oral  cancer).   At our MDT, the nature of surgery or the form of recon-  struction is rarely discussed. The certainty of achieving  tumor clearance and potential morbidity associated with  the treatment form the majority of the discussions. Speech  and language team assess the need for potential future  PEG (gastrostomy) or nasogastric feed. Where there is a  high index of suspicion that a PEG feed will be necessary,  this is done pre-treatment. Dieticians help in planning  feeding regimes both pre- and postoperatively. The restor-  ative dentist offers an opinion on unrestorable teeth that  need to be extracted at the time of surgery or prior to  chemoradiation to reduce the incidence of future  osteoradionecrosis.    The choice of reconstruction is numerous (Refer Chap. 82 to  read about principles of surgical management of oral cancer.  Chapter 85 deals with the access osteotomies to maxillofa-  cial region while Chaps. 86 and 88 deals with soft and hard  tissue reconstruction respectively). The preferred choice is  dependent on the following factors:    like for like. A simple but effective way of looking at recon-  struction would be:    Flaps for lining the defect in T2 defects—radial forearm  free flap, anterolateral thigh perforator flap (ALT), medial  sural artery free flap, submental flap, nasolabial flaps.  Flaps that are required for increasing bulk or low vol-  ume—anterolateral thigh flap, pectoralis major flap.  Flaps for major resection which require high volume—  rectus flap, latissimus dorsi flap.   Flaps for lining the pharynx—radial forearm free flap,  ALT, pectoralis major flap.   Skull base defects that require a long pedicle—rectus  abdominis flap, ALT, or latissimus dorsi free flap.   Bone reconstruction—fibula free flap, DCIA (deep cir-  cumflex iliac artery) flap, scapula flap.    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Som PM, Brandwein-Gensler MS. Lymph nodes of the neck. In:  Som PM, Curtin HD, editors. Head & neck imaging, vol. 2. 5th ed.  St Louis: Mosby; 2011. p. 2287-383.   Kuriokose M. Contemporary oral oncology, vol. 1 and 2. Cham:  Springer International Publishing; 2017.    Open Access This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.  org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropri-  ate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.    The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in    a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.   Management of oral cavity cancers in a curative intent set-  ting mainly involves surgery. The other treatment modalities  such as radiotherapy and chemotherapy are most commonly  used as adjuvant treatment based on the histopathological  features. However, it is to be noted that surgery alone is  insufficient to treat oral cancer. Chemotherapy is either con-  current with radiotherapy or in very rare scenario used as  induction therapy. The primary cancer treatment and risk  factor reduction are of utmost importance to improve effec-  tiveness of the primary treatment and to prevent development  of second-primary cancers.   Ablative surgery has evolved over the years with the  attempt to extirpate the tumor in its entirety with the under-  standing of the molecular tumor biology, pattern of tumor  invasion of the tumors, as well as availability of better  instrumentations.   With the advent of endoscopic assisted and robotic-  assisted neck dissection, the branch of oral oncology has  truly made progress, thus improving visualization and three-  dimensional navigation; however it is still in its infancy and  needs further research to understand the benefits over the  conventional methods.   This chapter outlines details of ablative surgery and ratio-  nale for addressing neck (node positive/node negative) in  patients with oral cavity cancers.    Electronic Supplementary Material The online version of this chap-  ter (https://doi.org/10.1007/978-98 1-15-1346-6_82) contains supple-  mentary material, which is available to authorized users.    M. A. Kuriakose (54)  Cochin Cancer Research Centre, Kochi, Kerala, India    © The Association of Oral and Maxillofacial Surgeons of India 2021   Initial evaluation as for any other medical condition includes  history, a clinical examination and investigations to form a  diagnosis. The other two important aspects influencing man-  agement of oral cavity cancer (mainly squamous cell carci-  noma) are habit history and performance status. Table 82.1  describes the performance status scales.   Staging of the disease is particularly important as it helps  the clinicians in better communication in a scientific forum  and forming a treatment plan for a patient. Various phases in  management of oral cancer include accurate diagnosis,  appropriate treatment plan, and execution of the advised  treatment with relevant reconstruction, rehabilitation, and  surveillance. So, to help clinicians in decision-making, there  are several guidelines that exist. As these guidelines have a  more generalized approach, it is the clinician’s knowledge    K. Bonanthaya et al. (eds.), Oral and Maxillofacial Surgery for the Clinician, https://doi.org/10.1007/978-98 1-15-1346-6_82    and understanding and experience which will help in tailor-  ing the treatment plan to each individual distinctly. This indi-  vidualized approach cannot be implemented unless there are  multidisciplinary tumor board meetings, which are crucial  for clinicians practicing oncology and hence provides team-  based practice keeping the patient in mind [2-4]. This is best  done before initiating the treatment.   To be able to know the extent of disease and decide the  intent and modality of treatment, imaging plays a very  important role. Precise imaging information is needed to  determine the locoregional extent, erosion, and involvement  of underlying bone and marrow space, lymph node involve-  ment and to rule out distant metastasis—especially to the  lungs. However the dilemma that most clinicians face is  which is the imaging modality of choice for different clinical  scenarios. In the following section, we attempt to provide  indications of each imaging type available, which probably  will help the clinicians in deciding what suits their needs.   Plain radiography is restricted to evaluation of pathologi-  cal fractures or initial benign lesions. Contrast-enhanced  computed tomography (CECT) is considered as the most  popular, easily available, and cost-effective diagnostic imag-  ing. It is the imaging modality of choice to know the pres-  ence of bone erosion and lymph node characteristic. Bony  expansion is usually a feature of slow-growing/benign dis-  ease process; however destruction of bone and replacement  by the tumor depicts the aggressiveness and hence is a fea-  ture of malignant process (Figs. : ; 3 and 82.4).    Fig. 82.1 Axial section of contrast enhanced CECT showing an ill-  defined heterogeneously enhancing mass lesion along the mandibular  alveolus involving the central lateral incisors and canines with erosion  of body of mandible    i Sagittal section of the patient same as Fig. to depict the  extent of bony erosion and involvement providing a guide for the  osteotomy    Fig. 82.4 Axial section—contrast-enhanced computed tomography. A  heterogeneously enhanced conglomerate of the lymph nodal mass at  left level IL with cystic areas highly suspicious of metastatic lymphade-  nopathy. The mass has partially compressed internal jugular vein and  pushed it posterolaterally    Magnetic resonance imaging (MRI) is usually indicated  as an adjunct as it has better soft tissue delineation. It is also  used for assessing dural invasion (linear or nodular), medul-  lary bone involvement, and _ perineural invasion.  Radiographic assessment of tumor extent is invaluable for  treatment planning. In case of tongue cancers, MRI has  gained popularity for assessment of tongue cancer espe-  cially as it is helpful in identifying tumor thickness, involve-  ment of the contralateral side, and involvement of extrinsic  muscles. With recent addition of depth of invasion in the  AJCC classification for staging, MRI has proven its role. As  for buccal mucosa tumors, assessment of masticatory mus-  cles involvement is crucial because it has historically been  considered unresectable. However, according to Liao, infra-  notch lesions are still amenable for resection with favorable  oncological outcome.   As oral cancers usually metastasize first to the lung, pre-  operative chest imaging is a part of initial pre-operative  work-up. This can be in the form of either plain film or 3D  imaging such as computed tomography (CT).  Fluorodeoxyglucose positron emission tomography (FDG-  PET) scan has emerged as the imaging modality of choice in  patient with recurrence and high clinical suspicion for dis-  tant metastasis (Figs. ; : and ).    82.5 The contrast-enhanced Tl-weighted MRI images depicting  hyperintensity involving the left lateral tongue with extension till the  midline and involving tip of the tongue    Fig. 82.6 Axial section of an MRI (T2-weighted) showing multiple  lymph node metastasis at level IB    Fig. 82.7. This is the whole body image of PET-CT scan depicting  uptake in the multiple areas suggestive of metastatic disease    It is to be noted that any suspicious lesions in PET-CT  scan needs to be corroborated with tissue diagnosis (direct or  guided) as there are a subset of lesions with false-positive  findings; however, PET-CT is considered to have the highest  negative predictive value approaching 100%. Although as  per the NCCN guidelines, PET-CT has to be advised for all  stage III and IV disease, it is usually reserved for patients  with recurrent or second primary disease in a resource-  constrained setting [5, 6]. Tables 82.2 and 82.3 provide  imaging considerations in oral cavity tumors.   Baseline follow-up imaging is usually done after  3 months, and CECT has established its role in ruling out  recurrence/residual disease. To avoid misinterpretation, it is    Fig. 82.8 FDG PET-CT images to show FDG avid lesion in the right  lower alveolus and ipsilateral level Il lymph nodes along with uptake in  the right nasopharynx. All the lesion have a similar standard uptake  value (SUV) of 15 corresponding to the metabolic activity    important that the concerned imaging radiologist is familiar-  ized with postoperative sequelae of tissue changes or changes  that occur following radiotherapy such as nonspecific tissue  thickening, edema, or fibrosis and various bony and soft tis-  sue reconstruction methods to facilitate interpretation.   Staging the disease is developed to provide ease of com-  munication and helps in understanding the prognosis and  planning the treatment. AJCC staging system has been fol-  lowed for years and provides concise information on size  characteristics and extent of primary tumor and involvement  of lymph nodes. The recent eighth edition has features like  tumor thickness, depth of invasion, and extranodal extension  (clinical and pathological).    In majority of oral cavity squamous cell cancers, surgery has  been the mainstay of treatment, and hence, the need to know  intricate surgical aspects has to be emphasized. As there has  been improved understanding of disease pattern, biologic  behavior of the disease at the molecular level, and the poten-    Table 82.4 Category for oral cavity cancer, eighth edition staging  manual [6]: Definition of primary tumor (T)    Radiological Advantages/  means Indications Challenges T category  T criteria  Computed Mainstay for imaging ¢ Bone details. TX Primary tumor cannot be assessed  tomography (CT) primary disease. ¢ Obscured to Tis Carcinoma in situ  dental artifacts. Tl Tumor <2 cm with depth of invasion (DOD* < 5 mm  SRR) Ba TaN iv) Tumor <2 cm with DOF > 5 mm  sou ead can be Or tumor >2 cm and < 4 cm with DOT’ < 10 mm  : eee mulssedlif: 13} Tumor >2 cm and < 4 cm with DOI’ > 10 mm  Magnetic ¢ Assessment of primarily ¢ Better contrast Onanmees cia satin DOW < 10 raven  Lapa Ona EE, Mesa ou ees T4 Moderately advanced or very advanced local disease  imaging (MRI) mouth, and hard palate Superior :  : : : T4a Moderately advanced local disease  lesions or bone marrow detection of B S  : : 2 Tumor >4 cm with DOI’ > 10 mm  involvement along with tumor spread into : :  Or tumor invades adjacent structures only (e.g., through  assessment of bone marrow. 2 : : :  : : cortical bone of the mandible or maxilla or involves the  nasopharyngeal, parotid, * Swallowing : 3 :  ; é maxillary sinus or skin of the face)  sinonasal tumors. artifacts [8]. : ;  Ae oct ae Note: Superficial erosion of bone/tooth socket (alone)  ¢ Useful in providing ies : i 4 ‘  We OGe an by a gingival primary is not sufficient to classify a  information on  : tumor as T4  encasement of carotid Z  artetiest T4b Very advanced local disease  * Promising results in Tumor invades masticator space, pterygoid plates, or  early detection of skull base and/or encases the internal carotid artery  perineural extension and “DOL is depth of invasion and not tumor thickness  detection of dural iD  involvement or suffix Definition  intracranial extension. (m) Select if synchronous primary tumors are found in single  Ultrasonography ° To identify lymph node organ  (USG) metastases. Definition of regional lymph node (N) clinical N (cN)  ¢ For assessment of tumor cN Category cN criteria  eee ah eee MR NX Regional lymph nodes cannot be assessed  eee eo NO No regional lymph node metastasis    N1 Metastasis in a single ipsilateral lymph node, 3 cm or  smaller in greatest dimension ENE    Positron emission * Diagnosis of an Tas: N2 Metastasis in a single ipsilateral node larger than 3 cm but  tomography unknown primary tumor, __ localization of not larger than 6 cm in greatest dimension and ENE  (PET) aeeeecmenton distant activity to normal Or metastases in multiple ipsilateral lymph nodes, none  metastasis, response to SeaBR oral larger than 6 cm in greatest dimension and ENE  therapy. Dae (rare / Sra ieeanetion Or in bilateral or contralateral lymph nodes, none larger  detection of recurrence. identification of than 6 ae ue eivatenl dimension, and ENE  Smimitedicolonnmec inflammatory N2a Metastasis in a single ipsilateral node larger than 3 cm but  ails eeluetion, lesions [5]. not larger than 6 cm in greatest dimension, and ENE  N2b Metastases in multiple ipsilateral nodes, none larger than  6 cm in greatest dimension, and ENE  N2c Metastases in bilateral or contralateral lymph nodes, none    Neck nodes USG-guided FNAC—100% specificity [10, 11] N3 Metastasis in a lymph node larger than 6 cm in greatest  RMT ¢ To look for bone erosion—Cortical bone or dimension and ENE,  marrow involvement. Or metastasis in any node(s) and clinically overt ENE  * To detect spread of lesion along N3a Metastasis in a lymph node larger than 6 cm in greatest  pterygomandibular raphae. dimension and ENE  Palate ¢ To assess invasion of maxillary sinus, palatal N3b Metastasis in any node(s) and clinically overt ENE  bone, and nasal vault. Note: A designation of “U” or “L” may be used for any N category  ¢ Depth of invasion dictates extent of resection. to indicate metastasis above the lower border of the cricoid (U) or  Infratemporal  * Pterygomandibular raphae provides pathway of below the lower border of the cricoid (L). Similarly, clinical and  fossa spread of lesion into ITF. pathological ENE should be recorded as ENE or ENE  ¢ CT & MR[ are useful. N  Tongue ¢ MRI is preferred; surrounding structure suffix Definition  involvement will help in deciding the extent of (sn) Select if regional lymph node metastasis identified by SLN  resection [12, 13]. biopsy only  Bone invasion ¢ MRLis superior for evaluating medullary space (f) Select if regional lymph node metastasis identified by FNA  of mandible but inadequate for assessing cortical or core needle biopsy only  invasion. U Metastasis above the lower border of the cricoid   Nl Metastasis in a single ipsilateral lymph node, 3 cm or  smaller in greatest dimension and ENE   N2 Metastasis in a single ipsilateral lymph node, 3 cm or    smaller in greatest dimension and ENE  Or larger than 3 cm but not larger than 6 cm in greatest  dimension and ENE;  Or metastases in multiple ipsilateral lymph nodes, none  larger than 6 cm in greatest dimension and ENE  Or in bilateral or contralateral lymph node(s), none larger  than 6 cm in greatest dimension, ENE   N2a Metastasis in single ipsilateral node 3 cm or smaller in  greatest dimension and ENE  Or a single ipsilateral node larger than 3 cm but not larger  than 6 cm in greatest dimension and ENE    N2b Metastases in multiple ipsilateral nodes, none larger than  6 cm in greatest dimension and ENE   N2c Metastases in bilateral or contralateral lymph node(s),  none larger than 6 cm in greatest dimension and  ENE   N3 Metastasis in a lymph node larger than 6 cm in greatest   Or metastasis in a single ipsilateral node larger than 3 cm  in greatest dimension and ENE    N3a Metastasis in a lymph node larger than 6 cm in greatest  dimension and ENE  N3b Metastasis in a single ipsilateral node larger than 3 cm in   Or a single contralateral node of any size and ENE  Note: A designation of “U” or “L” may be used for any N  category to indicate metastasis above the lower border of the  cricoid (U) or below the lower border of the cricoid (L).  Similarly, clinical and pathological ENE should be recorded as  ENE or ENE   (sn) Select if regional lymph node metastasis identified by SLN  biopsy only    (f) Select if regional lymph node metastasis identified by FNA  or core needle biopsy only    Definition of distant metastasis (M)  M category  cMO No distant metastasis    tial aggressive nature, the need has arisen for several techni-  cal modifications in this era. Hence as surgeons, we have to  evolve and adapt to the required changes to improve out-  comes of ablative surgery (oncological and functional) in  patients with squamous cell carcinoma of oral cavity.   For early-stage oral cavity cancers, especially tongue, it  has been proven that both surgery and radiotherapy/brachy-  therapy offer similar outcome (single modality). For  advanced lesions with extensive disease, multimodality  treatment is required; surgery being the primary modality  and followed by adjuvant radiotherapy +/— chemotherapy  (depending on the histopathological evaluation) has been the  standard of care.   4. Type of neck dissection in patients with metastatic  lymph nodes.    Decision 1 Primary intent of treatment: This is the first  and most critical decision-making point. All patients other  than those with technically unresectable tumors, distant  metastasis, poor performance status, and major comorbidi-  ties precluding surgery must be considered for treatment  with curative intent. However, it is to be noted that surgical  excision with positive margins portends poor prognosis.  Palliative care is usually when patient has distant metasta-  sis and given only to relieve symptoms and control spread.  This is in the form of chemotherapy, radiotherapy or  metronomics.    Decision 2 Curative modality of treatment: The primary  treatment for patients with oral cavity cancers is surgery.  However, in selected scenarios, non-surgical treatment may  be considered. This includes primary radiotherapy for tumors  of the commissure of mouth and lip tumors where surgery  can cause significant esthetic and functional disability. In  addition, significant comorbidities that preclude long anes-    thesia may necessitate the need for primary radiotherapy or  chemoradiotherapy. However primary chemoradiotherapy  has very limited role in treatment of oral cancers.    Decision 3. Management of neck in NO stage: Even with no  radiographic evidence of significant suspicious lymph-nodes,  rate of occult metastasis reaches up to as high as 30% [15].  Presence of lymph node metastasis and the number of lymph  nodes involved have a direct relation with the prognosis of the  disease; decreasing the overall survival rate by 50%. Moreover,  a significant subset of metastatic nodes of less than 1 cm can  have extranodal extension [16]. This further worsens the prog-  nosis. There is now level I evidence from a randomized control  trial, that addressing the neck surgically irrespective of the  lymph node status improves overall survival to about 84%  when compared to 69% in patients who were selected for  wait-and-watch policy [17]. Therefore, almost all the patients  with oral cavity cancer should undergo elective neck dissec-  tion. A subset analysis of the same study did not show benefit  for primary tumors of depth less than 3 mm. This may be con-  sidered in selected patients with cancers of lower nodal meta-  static prevalence such as lip and buccal mucosa.    Decision 4 Extent of neck dissection in N+ve oral squamous  cell carcinoma: Conventional teaching is that any patients  with N+ve neck should undergo modified radical neck dissec-  tion covering levels 1-5. This has been questioned by several  observational studies. Large cohort of patients who have  undergone radical neck dissection for N+ve disease has  showed less than 3% incidence of level V nodes [17]. This  also was observed only when there were pathologically posi-  tive level IV nodes [18]. There are reports of oncologic safety  for clearing level I-III lymph nodes for alveolus and buccal  mucosal cancers and to clear level IV in addition to levels I,  II, and I lymph nodes in patients with oral tongue cancers as  they bore high risk of skip metastasis [19]. It is to be noted  that when a patient is found to have pathological nodal metas-  tasis, in general, it is recommended for adjuvant radiation that  covers all levels of the neck with additional boost in the levels  which are positive for metastasis.    Decision 5 Indication for adjuvant radiotherapy: Any  patients with more than one of the high risk features should  be considered for adjuvant radiotherapy.    This includes (1) nodal metastasis without extracapsu-  lar extension, (2) perineural invasion, (3) lymphovas-  cular invasion, (4) poor differentiation, (5) close  margin (1-5 mm), and (6) depth of invasion over 1 cm.    But the absolute indication for radiotherapy is stage III and  IV disease.    Decision 6 Indication for adjuvant chemoradiotherapy:  Meta-analysis of two randomized trials has suggested that in  patients with positive surgical margin (<1 mm) and neck  nodes with extranodal extension would benefit from adju-  vant chemoradiotherapy.    Decision 7 Best supportive care options: This is an impor-  tant and critical decision. Once the decision for treatment  with palliative intent is arrived at, the goal should be made  clear with the treating team of doctors and the patient/  patient attenders. Ambiguity at this stage may result in loss  of trust between the treating team and the patient, causing  delay in treatment and possible increase in morbidity.  Although this decision is made in the multidisciplinary  tumor board, it requires series of meetings with the family  to convey the treatment goals. It is also essential to appreci-  ate by treatment group that lack of active treatment does not  mean stoppage of care, which needs to be provided by the  same team till the end. The quality of death is equally impor-  tant as quality of life.   The role of best supportive care is to palliate the symp-  toms the patients may have. In this situation, it is essential to  balance the morbidity of treatment versus potential benefit  the patient may receive. Often one may have ethical dilemma  when faced with young patients with locoregionally advanced  tumors. In this situation, temptation of surgery should be  tempered. One should consider surgery as palliation to alle-  viate fungating ulcers or to close a cutaneous fistula. The  goal of this surgery must be made very clear to the family. It  is essential not to give false hope to the family, which will  have deleterious consequence in the patient-physician rela-  tionship. In patients with good performance status, espe-  cially those who have not received previous radiotherapy,  one may consider chemoradiotherapy with curative dose,  with the goal to obtain durable palliation. In doubtful situa-  tions, induction chemotherapy followed by chemoradiother-  apy could also be considered. Local radiation or re-radiation  to a limited field may be considered for fungating ulcers. The  dose, fractionation, and volume of radiation field need to be  tailored for palliative purpose.   In patients with advanced metastatic disease, one needs to  be very selective in recommending systemic therapy as the  benefit is doubtful. Chemotherapy with targeted anti-EGFr  treatment has shown improved survival up to 4 months, with  significant morbidity associated with the regimen [20]. An  alternate approach is chemotherapy at metronomic dosing  regimen, especially the use of methotrexate and celecoxib  [21]. Recent evidence of nivolumab, a checkpoint inhibitor,  showing improved survival of about 3 months, and accept-  able morbidity, is to be considered. However the cost of the  treatment is a major deterrent for its wider application.  Table 82.5 provides the indications for adjuvant RT and adju-  vant CT + RT.    Table 82.5 Indications for adjuvant RT and adjuvant CT + RT    After various comparative studies, it has been concluded that  in adjuvant setting, postoperative IMRT has to be given at  dose of 60 Gy in 30 fractions to surgical bed and first echelon  nodal stations and the high-risk regions receive a total dose  of 66 Gy. It has to be remembered that for salvage surgery  cases, concept of re-irradiation should be explained to the  patient. A minimum of 12-month duration gap is required  prior to re-irradiation to allow for the spinal cord recovery.   In cases with postoperative histopathological features like  extranodal extension or positive surgical margins, patients  are treated with concurrent chemoradiation (usually 100 mg/  m’ of cisplatin for a maximum of 6 cycles in India). Indication  of chemotherapy as described is usually in adjuvant setting  in oral cavity cancers.   However role of chemotherapy as induction therapy is  evolving. Chemotherapy usually exerts its cytotoxic effects  systemically and hence associated with side effects. The  major drawbacks of chemotherapeutic agents used com-  monly are the adverse toxicities and cellular resistance. In an  induction setting, most commonly taxanes, platinum, and  SFU are used as 3 cycle regimen (also refer Chap. 84 of this  book on Adjunctive therapy in Oral Cancer).    Tumors of oral cavity which are considered techni-  cally unresectable are as follows:    ¢ Erosion of skull base, sphenoid bone, and widening  of foramen ovale.    These are considered unresectable not due to surgical  technicality but because of the inability to get negative mar-  gins and to achieve RO resection. However, with the superior  skills such as endoscopic-assisted surgeries which are asso-  ciated with less morbidity, and better adjuvant treatment  including chemotherapy, an attempt has been made to con-    sider resection of tumors involving muscles of mastication  and pterygoid plates especially with the anterior infratempo-  ral fossa involved. Recent studies have shown that surgical  resection of these tumors along with adjuvant treatment has  shown survival benefit. Also studies from Tata Memorial  Hospital, India have shown better outcome in patients who  have undergone surgical resection following neoadjuvant  chemotherapy.    The surgical approaches for tumors of oral cavity depends  primarily on the site of tumor (anterior versus posterior), its  size, and its proximity to bone (maxilla or mandible). The  various approaches frequently used for oral cavity cancers  are shown in Figs. 82.9, 82.10, 82.11, 82.12, 82.13, and  82.14 (Also refer Chap. 85 of this book on Access Surgeries  and Osteotomies of the Maxillofacial Region).   Types of mandibulotomy is shown in (Figs. 82.15, 82. 16a,  b) shows marginal mandibulectomy and segmental  mandibulectomy.    The tongue is a muscular organ which is composed of intrin-  sic and extrinsic muscles and divided anatomically into the  oral tongue (falls in oral cavity cancers) and base of tongue  (BOT, sub-site of oropharynx). The tongue is innervated by  the hypoglossal nerve, and vascularity is by lingual artery  (branch of external carotid artery). Pathway of tumor spread  from the oral tongue can be into the floor of mouth, mandi-  ble, or/and base of tongue via local extension, the lingual  septum being the barrier to tumor spread. For tumors abut-  ting the mandible, marginal mandibulectomy is indicated for  negative surgical margin encompassing the tumor and at the  same time preserving the mandibular continuity. Segmental  mandibulectomy is usually done when there is mandibular  erosion or paramandibular spread. Anterior segmental man-  dibulectomy is more commonly indicated in floor of the  mouth cancers.    Fig.82.9 Lip split incisions; (a) midline lip split (straight), (b) midline lip split with Z-plasty; (c) angle/commissure lip split; (d) straight  midline with chin contour; (e) straight midline with chin contour and Z-plasty at vermilion and submental region    Lingual artery is an end artery, and hence clinicians have  to be careful in resections involving more than two-thirds of  tongue mass as this may jeopardize the vascularity and utmost  care to be taken to preserve the neurovascular bundle.   There is a recent concept of compartment resection in  patients with infiltrative disease where the adjacent extrinsic  musculature and neurovascular bundle is excised in continu-  ity to ensure negative margins. This was proposed by  Calabrese [23], and all cases underwent access mandibulot-  omy; hence it is not commonly followed. Tumors of floor of  the mouth are usually infiltrative and lymph node metastasis  is seen bilaterally. According to Byers, the rate of lymph  node skip metastasis at level IV is observed in about 10-15%  cases. According to the study by Kowalski [24], tumors of  floor of the mouth, tongue cancers crossing the midline, and  advanced stage of the disease have a propensity of develop-  ing contralateral lymph node metastasis.    Fig. 82.11 Weber-Ferguson  incision for tumors of maxilla  not amenable to per-oral  excision and not requiring  infratemporal fossa access.  The upper cheek flap is raised  as shown    Fig. 82.12 A lower midline lip  split incision continued and  transverse neck skin crease  incision followed by raising of a  lower cheek flap. This gives the  best access to infra-temporal fossa.  The periosteum to be left on the  mandible to preserve its periosteal  blood supply. The mental  neurovascular bundle has to be  sacrificed   Wide local excision (WLE)/adequate glossectomy procedure  with adequate surgical margins has been the procedure of  choice for early tongue cancers, and this is amenable with  per-oral approach. Before planning resection, thorough  knowledge about the extent of lesion is important, and palpa-    tion of induration provides a guide for the same. Ideal mar-  gin for resection of tumour is all 1—1.5 cm all around. Usually  it is the deep soft tissue margin which is prone for being  close or positive, and this can be avoided by palpation  method. In many institutions, it is a useful practice to ligate  the lingual artery in the neck before performing WLE for    Fig. 82.13 This picture depicts access mandibulotomies for tumors  situated in the posterior tongue. The other alternative is pull through Fig. 82.14 Visor flap provides best access for total and subtotal    adequate bleeding control and clean surgical field. The  resulting defects of adequate glossectomy for early lesions  are usually closed primarily avoiding tethering of the tongue.  Excisional biopsy for suspicious lesions is highly discour-  aged even if the lesion is about 1 cm.   Moderately advanced cancers of the tongue and floor of  the mouth (T2-T3) warrant classical hemiglossectomy  which sacrifices the tip jeopardizing the tongue mobility  resulting in compromised speech and swallowing. Majority  of these tumors are excised by combinations of per-oral and  pull-through approaches, without the actual need for lip-  split or access mandibulotomy. The pull through technique  helps in avoiding positive posterior margins as the resec-  tion is done under direct vision. All these patients require  reconstructive surgery (lining or bulk), along with long-  term tracheostomy and feeding tube (ryles tube/PEG)  dependence. Free-flap reconstructions have become inevi-  table following resection of tongue cancers. Locally  advanced (T4a) cancers (tumor depth > 20 mm, restricted  mobility and hypoglossal palsy) of tongue warrant total  glossectomy or near-total glossectomy. Standard total glos-  sectomy procedure involves complete removal of anatomi-  cal tongue from mandible to hyoid and from the tip of the  tongue upto the vallecula.   The following a is brief outlay of surgical steps: anterior  belly of digastric muscle is first divided through the cervical  neck incision followed by intra-oral crevicular incision.  Then the genioglossus, geniohyoid is divided from the genial  tubercle and mylohyoid muscle from the mylohyoid line  from the mandible. At the contralateral retromolar region  come the division of buccopharyngeal fascia, styloglossus    muscle, and the palatoglossus muscle and incision at the val-  lecula. The same steps are repeated on the other side for total  glossectomy. However in near-total/subtotal glossectomy,  base of the tongue of uninvolved side is preserved. It is the  extent of excision of the base of tongue which determines the  postoperative swallowing function.   Tongue and the FOM lesions involving or abutting man-  dible pose a unique challenge. Resecting the segment of  mandible increases morbidity and reconstructive challenge  by many times. In such situations an attempt should be made  to preserve the mandible whenever possible.   Removal of the level V lymph node is reserved in situa-  tions when level IV or V is involved or in N3 nodal disease.  According to Kowalski et al., the indications for addressing  contralateral lymph nodes are lesions of the tongue crossing  the midline, floor of the mouth tumors, and locally advanced  T3 and T4 tumors [24].   Reconstruction of the tongue requires a soft tissue flap  with large volume to provide the adequate bulk which in turn  is believed to aid in swallowing. The drawback of a recon-  structed tongue is the impaired mobility resulting in compro-  mised speech. The most commonly used flap is radial  forearm free flap and anterolateral thigh free flap. The other  uncommon examples for free tissue transfer are lateral arm  flap, gracilis flap, and local flap such as FAMM flap and sub-  mental flap.   Reconstruction of tongue defect using radial forearm  free flap (Figs. 82.17, 82.18, 82.19, 82.20 and 82.21).   Reconstruction of tongue defect with local flap: facial  artery myomucosal flap (Figs. 82.22, 82.23, 82.24 and  82.25).    ; ©Association of Oral and Maxillofacial Surgeons of India  Fig. 82.17 Squamous cell carcinoma of left lateral border of the    Fig. 82.19 Completed left modified radical neck dissection  floor of mouth    Fig. 82.18 Post-surgical defect following left hemiglossectomy and  left marginal mandibulectomy    Bh y, 3  ©Association of Oral and Maxillofacial Surgeons of India    - — Fig. 82.23 Harvesting of facial artery myomucosal flap (FAMM)  ©Association of Oral and Maxillofacial Surgeons of India    Fig. 82.21 Radial forearm free flap inset into defect and anastomosed  to left facial artery and tributory of left internal jugular vein    Fig. 82.22 Tongue defect following wide local excision of left lateral  border tongue squamous cell carcinoma    completeness and appreciate depth. Inadvertent injury to the  buccal branch of facial nerve and to the parotid duct should    82.8.2 Buccal Mucosa be avoided. Facial artery, facial vein, and parotid duct (if  encountered or injured) should be ligated. Mucosal incision  82.8.2.1 1T1/T2 Lesions around the lesion, with adequate margin, taking the buccina-    tor muscle in specimen forms the deep soft tissue margin.  Surgical Steps: For Early Buccal Cancer Per-oral These defects can be reconstructed with split thickness skin  approach is adequate. It is important to ensure oncologic grafts/buccal pad of fat/local flaps such as nasolabial flap.    Fig. 82.26 Locally advanced T4a, left buccal mucosa lesion requiring  composite resection with excision of the overlying involved skin    Advanced T3/T4 Lesions (Lesions with Skin Involvement/  Bone _Involvement/Involvement of Muscles of  Mastication) Pre-operative clinical examination revealing  a subtle skin puckering and imaging studies shows stranding    Fig. 82.27 Defect following composite resection and modified radical  neck dissection; this defect was reconstructed with anterolateral thigh  free flap    of subcutaneous fat that is the early sign of skin involvement.  If buccal space involvement is suspected, then buccal fat pad  should be included in the specimen.    These advanced lesions require full-thickness cheek resec-  tion. The planning of incision may be a midline lip split or  angle split, both of which will help in raising a lower cheek  flap or when overlying skin is involved, an incision around  the skin involved in continuity with the neck dissection inci-  sion. The muscle of mastication involvement warrants infra-  temporal fossa clearance (Figs. 82.26, 82.27 and 82.28).    Gingivobuccal sulcus (GBS) tumors are tumors occurring in  the upper or lower GBS, usually seen to abut the bone adjacent  (Fig. 82.29). These occur almost exclusively in Southeast Asia  due to high incidence of chewing tobacco use. Due to the high  propensity for local invasion and close proximity of bone,  skin, and masticator space, presentation is often advanced, and  outcomes are poor. If there is superficial erosion of bone or if  the lesion is abutting the mandible, then the resection should  include marginal mandibulectomy. Superficial cortical erosion  in alveolar tumors is not considered as T4 lesion, and marginal  mandibulectomy may still suffice. Although MRI is consid-    Fig. 82.28 Excised specimen in toto (Same case shown in Figs. 82.26  and 82.27)    ered most sensitive imaging modality to determine extent of  bony involvement, periosteal stripping is by far the best  method to determine extent of bony erosion and helps in  decision-making regarding extent of mandibulectomy. GBS  tumors usually present at an advanced stage with gross man-  dibular erosion, paramandibular spread, or overlying skin  involvement (skin involvement is never seen in the masseter  region as it is a tumor barrier). These findings preclude the use  of marginal mandibulectomy, and hence patients often require  segmental mandibulectomy and bony reconstruction.    Retromolar trigone tumors are rare but more aggressive  malignancies with poorer outcome. Higher incidence of  local recurrence has been reported in squamous cell carci-  noma of the retromolar trigone (RMT) and posterior GBS  carcinomas. This is attributed to to its higher propensity of  infratemporal fossa (ITF) and pterygomandibular fissure  involvement. Due to restricted mouth opening at the time of  presentation, thorough clinical examination is hindered. For  both oncologic and anatomic reasons, tumors with mandibu-  lar invasion are best managed surgically by segmental man-  dibulectomy including coronoid process of the mandible.    The reason to preserve condyle is as follows: (a) it may  be used for secondary reconstruction, and (b) as the  condyle lacks medullary bone, it does not act as a path-  way of spread and hence can be oncologically safe to  preserve it.    Fig. 82.29 Classic example of a gingivo buccal tumor abutting the  adjacent mandible    As a large proportion of the RMT tumors involve both  the upper and lower jaw (Fig. 82.30), excision of ramus of  mandible in the form of subsigmoid marginal mandibulec-  tomy with at least an upper alveolectomy and ITF clearance  (anterior ITF comprising masseter and medial pterygoid  with or without pterygoid plates) is required. Selective neck  dissection comprising of level I-V lymph nodes is usually  performed electively for all stage cancers for purpose of  staging.    Tumors of the hard palate are less common when compared  to tumors of the mandible, tongue, or buccal mucosa and are  often of minor salivary gland etiology. Premaxilla provides  support for the nose and midface; lesions involving anterior  alveolus and hard palate will require bony reconstruction to  prevent midface deformity. Lesions of the posterior alveolus  and hard palate have a higher tendency to locally invade the  orbital floor and skull base or through various neurovascular  bundles (greater palatine foramen, sphenopalatine foramen,  palatovaginal canal).   Lymph node involvement is very rare for salivary neo-  plasm of the palate, and neck dissection is reserved only for  node-positive disease. However, maxillary alveolar carci-  noma has a high propensity for occult lymph node metastasis    Fig. 82.30 Left retromolar trigone squamous cell carcinoma extend-  ing to involve lingual surface of mandible, soft and hard palate  ipsilaterally    (15-20%), and also in patients where neck is not addressed,  they tend to present with nodal recurrences which are not  salvageable in two-thirds of the cases; hence it is wise to  consider elective neck dissection. The other point worth-  while and to be noted is that perifacial group of lymph nodes  have to be cleared for effective disease control for the upper  alveolus (Figs. 82.31, 82.32, 82.33 and 82.34).   for Maxillary Defects [25] (Fig. 82.35)  Vertical Component  e Class I, maxillectomy with no oroantral fistula.  ¢ Class II, low maxillectomy. ;  e Class III, high maxillectomy. ©Association of Oral and Maxillofacial Surgeons of India    resection of the hard palate; . . :  (b) resection of the bilateral alveolar maxilla and hard pal-    (a) resection of less than or equal to half of the alveolar ate, including a smaller resection that crosses the midline of  and hard palate, not involving the nasal septum or crossing _ the alveolar bone, including the nasal septum; and  the midline; (c) removal of the entire alveolar maxilla and hard palate.    Association of Oral and Maxillofacial Surgeons of Indi  ©Association of Oral and Maxillofacial Surgeons of India Coepenel Srahend Masilipiasiah ong ls    82.8.6 Lip Carcinoma ways; regional nodal metastasis occurs in only 10% of patients.   Full-thickness excision with up to 1 cm margin is necessary.  Squamous cell carcinoma of the lip is most frequently asso- Lesions that involve less than one-third of the lip are managed  ciated with sun exposure as the risk factor. Lower lip is more _ with simple wedge excision and primary closure and hence offer    commonly involved than the upper lip. Submental and subman- acceptable oncologic and reconstructive results. For lesions  dibular nodal basins are the primary echelon drainage path- larger than one-third but less than two-thirds, Abbe-Estlander or    T1/T2 NO Radiotherapy/brachytherapy vs. surgery  T3/T4 NO/ Surgery is mainstay of treatment followed by adjuvant  N+ therapy    Karapandzic flap can be utilized (refer Chap. 86 on Soft tissue  reconstruction of the Maxillofacial Region). For defects more  than two-thirds, free tissue transfer is preferred to achieve better  cosmetic result and avoid microstomia and oral incompetence.  To ensure oral competence, adjunctive procedures such as fas-  cial sling, palmaris longus sling, or temporalis muscle sling can  be used along with the adynamic soft tissue flap.   Table 82.6 describes the treatment modalities of use in  oral cancer.  82.8.6.1 Management of the Neck in Oral Cavity  Introduction  Although skip metastasis can occur, lymph node metastasis  usually follows a predictable fashion from the first echelon  nodes to the second echelon nodes. Tumors of the oral cavity  most commonly drain to levels I (submental and submandibu-  lar group) and level II (upper jugular group) in the neck. Level  IA is between the two anterior belly of digastric muscle, and  level IB is between anterior and posterior belly of digastric  muscle on either side. The submental triangle drains the ante-  rior portion of the oral cavity and hence can get involved in  the tumors of the incisor region, the anterior floor of mouth,  or anterior mandibular gingival/alveolar cancers. The level II  nodes are found between the level of the hyoid bone inferiorly  and anteriorly, the posterior belly of the digastric muscle  superiorly, and the posterior border of the sternocleidomas-  toid muscle (SCM) posteriorly. In the jugular chain, the level  Il lymph node station is demarcated inferiorly by the omohy-  oid muscle as it crosses the internal jugular vein (IJV) and  contains the mid-jugular lymph nodes particularly the promi-  nent omohyoid node lying in close relationship to the muscle.  Level IV (between the omohyoid muscle and the transverse  cervical vessels, medially bound by the IJV) and V (between  the posterior border of SCM and anterior border of trapezius  muscle, further divided into levels A and B by the spinal  accessory nerve) nodes are very rarely directly involved by  early initial spread of oral SCC. In addition to these classical  patterns of spread, buccal cancers may present with parotid  nodes, and the posterior maxillary alveolus/hard palate may  spread initially to retropharyngeal nodes. Tumors involving/  crossing midline and tumors of the floor of the mouth gener-  ally require bilateral neck dissection.    82.9 Evaluation and Diagnosis  Evaluation of neck disease for the purpose of staging is best    done by USG-guided FNAC, it being both highly sensitive  and specific, simple, and cost-effective but observer depen-    dent. Although palpation is most commonly employed, it has  a very low accuracy ranging between 50 and 65%. The limi-  tations of palpation method are obese patients or patients  with previously treated necks; examination is more difficult.  Imaging with CT scan or MR has been said to improve accu-  racy for metastatic neck disease to approximately 90%.  Chaukar et al. found contrast-enhanced CT to give better  concordance with histology in the NO neck than either US or  PET/CT.    ¢ The incision is made through the skin and deepened to  divide subcutaneous tissues. Thus exposing the platysma  (Thin pink muscle layer) which is incised in a single  stroke.   ¢ This is followed by raising of the subplatysmal flaps with  the superior limit being the lower border of the mandible;  anteriorly it is extends to the midline, posterior border of  sternocleidomastoid (SCM) muscle posteriorly, and infe-  riorly till the clavicle [26].   ¢ Neck dissection can be done either as an antero-posterior  fashion or as a postero-anterior approach.   ¢ Firstly the anterior belly of digastric muscle is identified,  and mobilization of the fibrofatty tissue begins between  the two anterior belly of digastric muscle and hyoid bone.   ¢ In level IB dissection, marginal mandibular nerve is identi-  fied and preserved. The next step is to divide the fascia  below the submandibular salivary gland, and the gland per  se is retracted cephalad. This maneuver exposes the poste-  rior belly of digastric muscle and helps in the identification  of the facial artery. It is ligated close to the entry point at  the posterior belly of digastric muscle and lower border of  mandible. However full length of the facial artery may be  preserved in case of full flap reconstruction [27, 28].   ¢ The Sub mandibular gland (SMG), fibrofatty tissue, lym-  phatics and the prefacial LNs are mobilized off the mylo-  hyoid and hence retracted it anteriorly.   ¢ For the level II-IV lymph node dissection, the fascia over  the SCM is raised till the posterior belly of digastric muscle  superiorly. Level IIA dissection begins with identification  of the Spinal accessory nerve (SAN) and Internal Jugular  Vein (IJV) and removal of the LNs, lymphatics, and fibro-    fatty tissue between these structures, the deep limit of dis-  section being the prepectoral fascia. At any given point on  time tractional injury to the SAN has to be avoided.   e This is followed by release of the fascia and tissue along  the posterior border of SCM till the clavicle inferiorly;    mylohyoid muscle retracted inferiorly and lateral border  of IJV identified. Care is taken to preserve deep cervical  plexus. Now the level II-IV tissue is retracted anteriorly  and peeled off the IJV and continued in the anterior tri-  angle of the neck till the midline, preserved the superior  thyroid vessels and tributary of IJV.   Level IIB is dissected between the posterior belly of  digastric and postero-superior to the SAN, posterior limit  being SCM.    Fig. 82.40 Exposed SCM, greater auricular nerve, and external jugu-  lar vein can be seen over the SCM    e'  "7 mi. * ©Association of Oral and Maxillofacial Surgeons of India  ©Association of Oral and Maxillofacial Surgeons of India  Fig. 82.43 Completed selective neck dissection (level I-IV) preserv-  Fig. 82.41 Spinal accessory nerve exposed in level II region ing sternocleidomastoid (SCM), spinal accessory nerve (SAN), internal  jugular vein (IJV)   (level I-V) preserving only internal jugular vein with suction drains in   If hematoma, “milking” the drains may result in  evacuation. It is best to return the patient to the  operating room and explore the wound if there is  suspicion of active bleed and/or there is evidence  of hypotension.   SAN in the level II may be injured either tractional  or due to vascular compromise. Vagus, lingual,  hypoglossal, and marginal mandibular branch of  the facial nerves should be identified and  preserved. All attempts should be made to preserve  the greater auricular nerve too   This usually occurs when the internal jugular vein  is ligated. When one internal jugular vein is  ligated, the pressure rises by three-fold and when  both are ligated it increases by five-fold. This  usually is temporary and will normalize in 24 h. If  it persists, head end elevation, steroids, and  mannitol can be used   Any tears in the pleura should be identified and  closed and their integrity tested    Basal atelectasis and bronchopneumonia may  occur in patients who are smokers and have  pre-existing chronic obstructive lung disease   This is seen in patients in geriatric age group,  prolonged duration of surgery, bedridden patients,  and patients with previous history of deep vein  thrombosis, pulmonary embolism, myocardial  infarction and thrombophilia   Intra-operative identification can be aided by  placing the patient in the Trendelenburg position  or adopting a forced Valsalva maneuver.  Postoperative leaks are usually identified when  feeding is commenced.   Multiple approaches to the treatment of an  established leak have emerged including  nutritional, surgical, and pharmacological therapy  Damage to the adventitial layer during surgery  may be another contributory factor. If risk of  exposure is anticipated, vessels should be covered,  e.g., dermal graft, fascia lata or levator scapulae  muscle flap. This is particularly important in the  post-irradiation subject    Fig. 82.45 Composite resection with left hemimandibulectomy and Lymphedema  selective neck dissection (Level I-IV) preserving the non-lymphatic    Table 82.7 provides a comprehensive view of the complica-  tions arising from neck dissection [29].    When both the internal jugular veins are ligated,  lymphedema often follows owing to interruption  of the lymphatic drainage channels.    1. West H, Jin JO. Performance status in patients with Cancer. JAMA  Oncol. 2015;1(7):998.  2. 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Open Access _ This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.  org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropri-  ate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.    The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in    a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statu-  tory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.   Sarcomas are uncommon malignant tumours with incidence  of less than 5% of all head and neck malignancies in adults  [1, 2]. They are more common in children, accounting for  30% of head and neck sarcomas [2, 3]. They arise from either  soft or hard tissue mesenchyme cells. There is a male pre-  dominance and presentation is usually in the third and fourth  decade of life in 70% of cases [4, 5].   Metastasis at initial presentation is seen in only 10% of  patients, usually from high-grade primary lesions [6-8].  Despite this, prognosis tends to be poor, partly due to the  proximity of vital neurovascular structures leading to diffi-  culty in obtaining adequate surgical clearance. Moreover,  majority of the sarcomas are poorly differentiated, a poor  prognostic marker [9].   Sarcomas tend not be related to the use of tobacco and  alcohol. Predisposition to the development of sarcomas is  seen in some conditions [4, 8, 10]. Notable examples include  association of osteosarcoma in patients with Li-Fraumeni  syndrome, angiosarcoma with chronic lymphoedema and  Kaposi’s sarcoma with HIV infection. Additionally, expo-  sure to chemicals such as vinyl chloride is well-recognised  risk factors [10].    Broadly speaking, sarcomas can be classified into two cate-  gories: soft tissue and hard tissue (bone and cartilage) sarco-  mas. This, however, is an oversimplification since precise  classification is fraught with significant difficulties. For  example, fibrosarcoma and malignant fibrous histiocytoma  are soft tissue sarcomas that arise in hard tissues [11, 12]. In  contrast, chondrosarcomas are classified as soft tissue    D. S. Jacob (x!) - B. Raghu  Maxillofacial Unit, Royal Surrey County Hospital, Guilford, UK  e-mail: dsouzaj @icloud.com; raghusurgdent @ doctors.org.uk    © The Association of Oral and Maxillofacial Surgeons of India 2021 
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