The resultant damage to bone following radiation for carcinoma is a severe complication24and difficult to treat. The primary pathological process is necrosis of bone, but infection and residual cancer often complicate the picture. The patient suffers severe unremitting pain and may have a draining wound, fetor oris, and trismus. In the head and neck, the mandible is most frequently involved. The essentials of treatment are wide removal of the affected bone plus coverage by adequate soft tissue with good blood supply. Pathogenesis.— Late change in arteries (obliterative endoarteritis) gradually shuts off the blood supply provided by osseous nutrient vessels and periosteum.25As long as there is viable soft tissue coverage, these changes, although progressive and inexorable,26remain unnoticed. Should the skin or mucosal covering be broken, however, infection from the surface bacteria can spread rapidly through the fibrotic, nearly bloodless, soft tissue where defensive mechanisms have