Osteoradionecrosis (ORN) is one of the most serious oral complications of head and neck cancer treatment with radiotherapy. There is bone tissue necrosis and failure to heal. The bone becomes devitalized and exposed through the overlying skin or mucosa, without healing for 3 months, without the recurrence of tumor. We review the etiological factors implicated in the ORN and describe the influence of infection, radiation therapy, dental status, and surgery. Finally, we present the currently accepted therapeutics procedures for the management of osteoradionecrosis.Keywords Osteoradionecrosis Á Jaws Á Bone necrosis Osteoradionecrosis (ORN) is one of the most serious oral complications of head and neck cancer treatment. It is characterized by a severe delayed radiation-induced injury, characterized by bone tissue necrosis and failure to heal [1-3], and several definitions have been proposed. One of the most widely accepted is that published by Harris [4]. He describes ORN as an irradiated bone that becomes devitalized and exposed through the overlying skin or mucosa, without healing for 3 months, without the recurrence of tumor. Marx [5] defined ORN as an area greater than 1 cm of exposed bone in a field of irradiation that had failed to show any evidence of healing for at least 6 months.Given the increased use of radiation therapy (RT) and combined chemotherapy-radiation therapy (CRT) regimens in the treatment of head and neck malignancies, it is anticipated that osteoradionecrosis will continue to be an important clinical problem [6], though newer radiotherapy techniques may reduce ORN to a degree, as discussed below.No studies to date have systematically addressed the impact of ORN on either quality of life or cost of care [7].
EpidemiologyIn a retrospective study of 830 patients with head and neck tumors who received radiotherapy between 1969 and 1999, there was an incidence of ORN of 8.2% and a threefold higher incidence in men than in women [8]. In contrast, Cheng et al. [9] in 2006 found the prevalence to be 2.7%.New cancer treatment strategies such as intensity-modulated RT (IMRT) and concomitant CRT have had disappointingly minimal effect on the prevalence of ORN. In a review of 43 articles published between 1990 and 2008, Peterson et al. [7] found that the weighted prevalence for ORN in conventional RT was 7.4%, for IMRT 5.1%, CRT 6.8%, and brachytherapy 5.3%.
EtiologyThe cause and pathogenesis of osteoradionecrosis are far more complex than originally believed [6]. Recent theories for the pathogenesis of ORN have proposed that bone