Mandible Osteoradionecrosis

Osteoradionecrosis (ORN) of the mandible is a severe iatrogenic disease of devitalized bone caused by radiation therapy of oral and oropharyngeal cancers. It is a state of injured bone tissue with inadequate healing or remodeling response of at least three to six months. The wound can result from radiotherapy combined with mechanical insult or radiotherapy exposure alone. ORN is separate from primary bone infection or persistent/recurrent malignancy, though its clinical presentation can mimic both. While there is no universally accepted pathophysiologic description, relative tissue hypoxia and the potential effects of free radicals are commonly cited mechanisms and form the basis of most treatment strategies.