Chapter 19
Mandibular Osteoradionecrosis
Epidemiology
Radiation therapy is used extensively for the treatment of head and neck malignancies. The mandible is often included within the treatment portal, especially in the treatment of tongue or floor of mouth tumors. Although the mandible can withstand high doses of irradiation, osteoradionecrosis may be seen in up to 6% of patients following external beam irradiation. The frequency increases to 21% when radium implants are given in addition to external beam irradiation.
Clinical Findings
Patients with osteoradionecrosis usually present with associated mucosal ulceration, bone exposure, and pain. Osteoradionecrosis in the absence of bone exposure is uncommon. Soft tissue swelling and superimposed infection may be present. Most patients present with signs or symptoms 3 to 12 months following irradiation, but some patients present many years later.
Pathology
Histology shows damaged cellular elements of bone and vascular changes. Microorganisms may be seen on the surface of the affected bone in contrast to osteomyelitis where the pathogenic organisms are found deep within bone. The most common sites of mandibular osteoradionecrosis are the mylohyoid line and the anterior arch of the mandible.
Treatment