Osteoradionecrosis of the temporal bone.

A series of twenty-nine cases of osteoradionecrosis of the temporal bone is described. Two patterns occur: a localized involvement of the tympanic plate which resolves after the spontaneous separation of a sequestrum of bone, and a more diffuse necrosis of the temporal bone with a high risk of involvement of adjacent structures, in particular the brain, labyrinth and facial nerve and to a lesser extent the temporomandibular joint and the parotid gland. Localized osteonecrosis occurs more commonly when the temporal bone is in the periphery of an irradiated field whereas irradiation aimed primarily at the temporal bone is more likely to be followed by diffuse disease. The use of megavoltage irradiation has not led to the disappearance of the complication which may occur as much as twenty years after the completion of the course of radiotherapy.