***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
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    Input: PURPOSE The aim of the present study is to compare piezoelectric surgery to the conventional rotatory surgery in m and ibular cyst enucleation , and to determine the 2 method 's suitability and the postoperative outcomes . MATERIAL AND METHODS Eighty patients were included in the study . 35 male and 45 female , which showed cystic m and ibular lesions , compared with the inferior alveolar nerve or the mental nerve . The patients were r and omly divided into two groups . In the test group , cystectomy was performed using conventional rotatory instrumentation ( rotatory-group ) , and in the other one piezoelectric surgery ( piezo-group ) . The swelling was documented 24/48/72 h and 1 week post-surgery and the patients recorded their subjective postoperative pain daily for 7 days using a Visual Analog Scale ( VAS ) . RESULTS Patients treated with piezoelectric technique have presented a lower VAS , minor swelling and less recovery time compared to the rotatory-group . No lesions of the m and ible nerve were detected with piezosurgery whereas surgery with rotary instruments result ed in 8 % hypesthesia at least up to one week . CONCLUSION The results of this study suggest that piezosurgery may be considered effective in cyst enucleation compared to traditional procedures with burs , since it grants the patients significantly less post-surgical pain and swelling Flaws in the design , conduct , analysis , and reporting of r and omised trials can cause the effect of an intervention to be underestimated or overestimated . The Cochrane Collaboration ’s tool for assessing risk of bias aims to make the process clearer and more Purpose This clinical trial aim ed to test the hypothesis that piezosurgery causes reduced nerval irritations and , thus , reduced somatosensory impairment when used in orthognathic surgery of the m and ible . Methods To this end , 37 consecutive patients with Angle Class II and III malocclusion were treated using bilateral sagittal split osteotomies ( BSSO ) of the m and ible . In a split mouth design , r and omized one side of the m and ible was operated using a conventional saw , while a piezosurgery device was used on the contralateral side . In order to test the individual qualities of somatosensory function , quantitative sensory testings ( QSTs ) were performed 1 month , 6 months and 1 year after surgery . Results A comparison of the data using a two-way analysis of variance ( ANOVA ) revealed a significant reduction in postoperative impairment in warm detection threshold ( WDT ) ( P = 0.046 ) , a decreased dynamic mechanical allodynia ( ALL ) ( P = 0.002 ) and a decreased vibration detection threshold ( VDT ) ( P = 0.030 ) on the piezosurgery side of the m and ible as opposed to the conventionally operated control side . In the remaining QSTs , minor deviations from the preoperative baseline conditions and a more rapid regression could be observed . Conclusions Piezosurgery caused reduced somatosensory impairment and a faster recovery of somatosensory functions in the present investigation The aim of this report is to present preliminary results and experiences using an ultrasonic bone-cutting device in bilateral sagittal split osteotomies of the m and ible ( BSSRO ) with particular attention to possible damages to the inferior alveolar nerve ( IAN ) . Seven patients with class II or class III malocclusion were treated by BSSRO with a conventional combined orthognathic and surgical approach . The osteotomy was carried out using an ultrasonic bone-cutting device .  Subjective neurosensory deficits of the inferior alveolar nerve were assessed on 14 sides . Compared to the conventional techniques using saws , chisels and burs , the use of the ultrasonic device was more time-consuming , but the osteotomies were carried out at a high level of precision . In addition , this procedure offered the advantage of a blood-free surgical field and thus provided good control of the surgical procedure . Subjective neurosensory disturbances of the IAN showed a continuous decrease from 57.1 % ( eight sides ) 2 months after the surgical procedure to 14.3 % ( 2 sides ) after 5 months and to 7.1 % 7 months after BSSRO . Within the seven patients of this pilot study associated neurosensory disturbances were low . A possible advantage in terms of nerve protection is subject to a prospect i ve study Background Ultrasonic bone-cutting surgery has been introduced as a feasible alternative to the conventional sharp instruments used in craniomaxillofacial surgery because of its precision and safety . The piezosurgery medical device allows the efficient cutting of mineralized tissues with minimal trauma to soft tissues . Piezoelectric osteotome has found its role in surgically assisted rapid maxillary expansion ( SARME ) , a procedure well established to correct transverse maxillary discrepancies . The advantages include minimal risk to critical anatomic structures . The purpose of this clinical comparative study ( CIS 2007 - 237-M ) was to present the advantages of the piezoelectric cut as a minimally invasive device in surgically assisted , rapid maxillary expansion by protecting the maxillary sinus mucosal lining . Methods Thirty patients ( 18 females and 12 males ) at the age of 18 to 54 underwent a surgically assisted palatal expansion of the maxilla with a combined orthodontic and surgical approach . The patients were r and omly divided into two separate treatment groups . While Group 1 received conventional surgery using an oscillating saw , Group 2 was treated with piezosurgery . The following parameters were examined : blood pressure , blood values , required medication , bleeding level in the maxillary sinus , duration of inpatient stay , duration of surgery and height of body temperature . Results The results displayed no statistically significant differences between the two groups regarding laboratory blood values and inpatient stay . The duration of surgery revealed a significant discrepancy . Deploying piezosurgery took the surgeon an average of 10 minutes longer than working with a conventional-saw technique . However , the observation of the bleeding level in the paranasal sinus presented a major and statistically significant advantage of piezosurgery : on average the bleeding level was one category above the one of the remaining patients . Conclusion This method of piezoelectric surgery with all its advantages is going to replace many conventional operating procedures in oral and maxillofacial surgery . Trial registration CIS 2007 - We investigated the average operating time and extent of intra-operative blood loss in  orthognathic surgeries performed using induced hypotensive general anaesthesia , with the intention of devising a practical guideline for blood unit preparation for these procedures . We prospect ively studied 32 Chinese patients undergoing surgery to correct dentofacial deformities at a public hospital in Hong Kong from 1 December 1997 to 1 December 1998 . Most patients ( 72 . 4 % ) needed double-jaw surgery . The mean estimated blood loss was approximately 617.6 mL. The blood loss during simple Le Fort I osteotomies was about half that of multiple segmentalised osteotomies . For m and ibular ramus osteotomies , the mean blood loss and operating time for were approximately 280 mL and 2 hours , respectively ; for anterior m and ibular osteotomies , the corresponding values were 171.3 mL and 1 hour 13 minutes . The average drop in the haematocrit value was 15.4 % , and the crossmatch to transfusion ratio was 29 . A bivariate correlation test between the blood loss and operating time gave a strong correlation ( P<0.01 ) , as did blood loss with a drop in haematocrit value ( P<0.01 ) . Orthognathic surgeries are thus safe and predictable in terms of intra-operative blood loss and operating time , and a ' type , screen , and save ' policy for blood unit preparation is more appropriate than a ' crossmatch ' policy Introduction Piezoosteotomy was assessed as alternative osteotomy method in orthognathic surgery regarding h and ling , time requirement , nerve and vessel impairment . Material s and methods In this comparative clinical experience , 90 patient ’s orthognathic surgery procedures were performed in typical distribution prospect ively by piezoosteotomy : 34 ( 38 % ) monosegment , 47 ( 52 % ) segmented LeFortI osteotomies , 94 ( 52 % ) sagittal split osteotomies , 11 ( 12 % ) symphyseal , and 4 ( 2 % ) m and ibular body osteotomies . As controls served 90 retrospective patients with conventional saw and chisel osteotomy : 58 ( 64 % ) monosegment , 27 ( 30 % ) segmented LeFortI osteotomies , 130 ( 72 % ) sagittal split , and 4 ( 4 % ) symphyseal osteotomies . Results and discussion Piezoosteotomies were individually design ed to interdigitate the jaw segments after repositioning . The pterygomaxillary suture weakened angulated tools ; auxiliary chisels were required in 100 % of cases for the nasal septum and lateral nasal walls , in 33 % for pterygoid processes . The dorsal maxilla as the pterygoid process were easily reduced ; 15 % m and ibular osteotomies required sawing , while the lingual dorsal osteotomy was performed by manual feedback due to limited visibility . Bloodloss decreased from average 537 ± 208 ml vs. 772 ± 338 ml ( p = 0.0001 ) . Operation time remained unchanged : 223 ± 70 min vs. 238 ± 60 min ( p = 0.2 ) for a conventional bimaxillary procedure . Clinical courses and reossification were unobtrusive . Alveolar inferior nerve sensitivity was retained in 98 % of the piezoosteotomy collective versus 84 % of controls ( p = 0.0001 ) at 3 months postoperative testing . Conclusion Piezoelectric osteotomy  did not prolong the operation and reduced blood loss as alveolar nerve impairment . A few patients required additional sawing or chisel . Piezoelectric screw insertion as complex osteotomies may be initiated to simplify the procedure and increase segment interdigitation after repositioning as to minimize the osteofixation time and dimensions PURPOSE Autologous blood donation is not routinely recommended for all cases of  orthognathic surgery . The aim of this study was to evaluate the factors for blood loss during bimaxillary osteotomies that might indicate preoperative blood donation . PATIENTS AND METHODS In a prospect i ve study , 127 consecutive patients undergoing bimaxillary surgery within a 14-month period were examined for hemoglobin and hematocrit reduction . Possible factors for intraoperative blood loss such as operating time , application of hydroxyethyl starch in segmental osteotomies , experience of the surgeon , and additional procedures ( genioplasty , malar osteotomy , iliac crest graft ) were statistically analyzed . RESULTS The experience of the surgeon had no influence on the blood loss . Operating time and Quick value correlated significantly with hemoglobin and hematocrit drop after surgery . There was no difference between 1-piece maxilla cases with or without additional procedures and segmental maxilla cases without additional procedures . Only for the group of patients with segmental osteotomies and additional procedures was a significant higher blood loss found . Two patients ( 1.6 % ) received 1 unit of blood . CONCLUSION For patients undergoing bimaxillary osteotomies with segmentation of the maxilla and additional procedures , a preoperative donation of autologous blood should be considered Abstract The aim of the study was to compare in a r and omized controlled clinical trial the use of the piezoelectric osteotomy as an alternative to the conventional approach in terms of surgery time , intraoperative blood loss , cut quality , nerve injury , and costs .  One hundred ten patients who had orthognathic surgery procedures with bimaxillary osteotomy were divided into 2 groups : group A was treated with a piezosurgery device , and group B , with a reciprocating saw and bur . The piezosurgical bone osteotomy permitted individualized cut design s. The surgical time in group A was reduced , with a mean for the m and ibular osteotomy ( 1 side ) between 3 minutes 31 seconds and 5 minutes 2 seconds , whereas in group B , the surgical time was between 7 minutes 23 seconds and 10 minutes 22 seconds . The surgical time in group A for the Le Fort I osteotomy was between 5 minutes 17 seconds and 7 minutes 55 seconds in group A and between 8 minutes 38 seconds and 15 minutes 11 seconds in group B. All patients in group A had a low blood loss ( < 300 mL ) versus patients of group B who had a medium to high blood loss ( medium loss : 400 mL , high loss : > 500 mL ) . Inferior alveolar nerve sensation was retained in 98.2 % of group A versus 92.7 % in group B at 6 months postoperative testing . Piezoelectric osteotomy reduced surgical time , blood loss , and inferior alveolar nerve injury in bimaxillary osteotomy . Absence of macrovibrations makes the instrument more manageable and easy to use and allows greater intraoperative control with higher safety in cutting in difficult anatomical regions PURPOSE Piezo-osteotomy feasibility as a substitute for the conventional saw in orthognathic surgery was evaluated regarding operative technique , blood loss , time requirement , and nerve and vessel integrity . PATIENTS AND METHODS Fifty patients had orthognathic surgery procedures in typical distribution using piezosurgical osteotomy : 22 ( 44 % ) monosegment , 26 ( 52 % ) segmented Le Fort I osteotomies ; 48 ( 48 
    Output:
    
Currently available evidence suggests that piezo-surgery has favorable effects on complications associated with orthognathic surgery , including reductions in intraoperative blood loss and severe nerve disturbance