Guidelines for Complications of Cancer Treatment Vol VIII Part B

The incidence is usually lower after hyperfractionatedradiotherapy at 72–80 Gy, or moderately acceleratedfractionated radiotherapy together with a boost of64–72 Gy.Its incidence can be decreased with the use of intensitymodulatedradiotherapy.The incidence is higher in dentate than in edentulouspatients.Clinical presentation Pain, chronic non-healing fistulae, sinus through the skinor alveolar mucosa, exposed bone in a region that hasbeen irradiated. Dysaesthesia, halitosis, dysgeusia. The interval between radiation and occurrence of ORNvaries from 4-12 months. It may sometimes manifest afterlonger intervals in the presence of trauma. May present earlier with history of trauma, postradiotherapy.Various staging systems have been proposed based on severityand response to treatmentFactors influencing the occurrence of ORN Size and site of tumor: Larger tumors in proximity tothe mandibular alveolus, in the presence of other factorsmay predispose to ORN. Dose of radiation: The type of radiation, whetherexternal beam or brachytherapy or a combination of thetwo, the volume radiated, proximity and dose to theadjacent bone, fractionation, dose per fraction and totaldose play an important role in the manifestation of ORN. Type of Mandibular resection: Resection of largesegments of the mandible, especially the posteriorsegment may predispose to ORN.159