Osteoradionecrosis: Oral Health And Dental Treatment

Abstract

Osteoradionecrosis (ORN) of the jaws is most commonly defined clinically as an area of previously irradiated, devitalized, exposed bone that fails to heal over a period of three to six months, in the absence of local neoplastic disease. It is thought to be caused by radiation-induced fibro-atrophic tissue injury.1 ORN is associated with considerable morbidity and has important ramifications for the quality of life of cancer survivors.2,3 Principal manifestations include pain, and, more rarely, dysesthesia and anesthesia.4 These may be further complicated by secondary infection and fistula formation, as well as dysgeusia, dysphagia, dyspnea, xerostomia, pathologic fracture and mechanical impairment of speech.4 Many classification systems have been devised in order to stratify the wide spectrum of clinical presentations of ORN; however, their adoption has been far from universal and none has been validated with large-scale clinical trials,5 posing difficulties for the comparison of controlled interventions and potential disparities in reporting rates. The reported incidence of ORN in head and neck cancer patients with an absorbed radiation dose to the mandible or maxilla is highly variable.6,7 Clayman 1997 found the overall incidence (not stratified by risk) before 1968 reached 11.8%, while it dropped to 5.4% between 1968 and 1992, presumably with the widespread adoption of more directed, high-energy supervoltage/megavoltage therapy.6 More recently, an incidence of 3% was reported in a sample of patients treated between 1997 and 2006.7 The true incidence may in fact be higher due to under-reporting of this condition secondary to inadequate or variable follow-up periods in published studies.8,9