This leads to uncertainty for clinicians and patients on deciding the best treatment that can be provided.There are a number of classifications of ORN stages present with different basis of staging and most updated one being the Notani classification. The Notani classification of stages is based on the radiographic and clinical findings, with studies describing low grade ORN being treated conservatively and advanced ORN including pathological fractures, and oro-cutaneous fistula treated surgically. Prevention
Prior to radiotherapy
Dental assessment
It is recommended to have a multi-disciplinary approach to care and dental assessment before the patient undergoes radiotherapy. It has been reported, that analysis of patients who have a strict preventive regime paired with IMRT resulted in no cases of ORN. Dental extractions
As dental extractions are a major risk factor in ORN development, it was recommended to extract all teeth prior to radiotherapy. However, this is now discouraged as a treatment of choice and has many disadvantages. According to one study, the frequency of ORN pre-radiotherapy extractions and post-radiotherapy extractions are almost the same. Extractions of teeth of poor prognosis, usually less than five years is recommended and planning should take into account the likely future problems with oral care, for example if severe trismus develops and if dentures were to be prescribed, denture trauma may cause ORN. The patient’s wishes must also be taken into account.If teeth are required to be extracted, they should ideally be completed as soon as possible to maximise healing prior to radiotherapy. One study recommended a minimum of 14–21 days prior to radiotherapy.
Post-radiotherapy
Patients will still be susceptible to radiation caries and periodontal disease, more so if they present with dry mouth or access difficulty when tooth brushing. Any restorative or periodontal procedures should be commenced if indicated and endodontic treatments should take priority over extractions, although if there is a difficulty in mouth opening, endodontic treatments can be difficult or impossible. Where a tooth is deemed unrestorable, decoronation can be done. Although dentures should be avoided if a shortened dental arch is manageable, if a denture is required or being used, they should be checked routinely and any adjustment to pressure areas should be made to avoid ORN secondary to denture trauma. Extractions post-radiotherapy
A practical recommendation  is provided in some case where it is necessary to extract teeth from the jaw after radiotherapy. An assessment of the risk of ORN should be done based on the dose of radiation, the site and how easy is the extraction. Any information on risk and early signs of ORN should be given to the patient. The recommendations are listed below, however, there are some controversies on the ideal antibiotic regime and the use of hyperbaric oxygen therapy (HBO).Summary of recommendations:
0.2% chlorhexidine mouthrinse given before extraction
Oral antibiotics(3g) given 1 hour prior to extraction ( if allergic 600 mg clindamycin)
Amoxicillin 250 mg 3 times/day or metronidazole 200 mg 3 times/day for 3–5 days post-operatively.