Mandibular osteoradionecrosis (ORN) is more common after radiation therapy for head and neck malignancies due to the superficial position of the mandible, which exposes it to high radiation. The maxilla can also be involved, but this is less frequent.
Mandibular ORN may occur in ~20% (5-37%) of patients 2,4.
Mandibular ORN typically occurs in patient who have received a dose of >60 Gy 4. Osteoradionecrosis changes may occur within a year of therapy.
Features include 2,4
- cortical destruction that is ill-defined resulting in a mixed sclerotic-lucent pattern
- sequestration, especially of the buccal bone
- absence of soft tissue mass is an important feature to differentiate it from neoplastic recurrence but the presence of soft tissue does not exclude ORN
Treatment and prognosis
Conservative treatment is initially medication only (e.g. pentoxifylline, vitamin E) but more severe cases may require hyperbaric oxygen therapy and/or debridement. Some patients will require resection and reconstruction of the mandible 3.
- pathological fractures
- radiation-induced neoplasia
- drug-related osteonecrosis, e.g. bisphosphonate-related osteonecrosis of the jaw (BRONJ)
- chronic osteomyelitis
- 1. Mitchell MJ, Logan PM. Radiation-induced changes in bone. Radiographics. 1998;18 (5): 1125-36. doi:10.1148/radiographics.18.5.9747611 - Pubmed citation
- 2. Chong J, Hinckley LK, Ginsberg LE. Masticator space abnormalities associated with mandibular osteoradionecrosis: MR and CT findings in five patients. AJNR Am J Neuroradiol. 2000;21 (1): 175-8. AJNR Am J Neuroradiol (full text) - Pubmed citation
- 3. Mendenhall WM. Mandibular osteoradionecrosis. J. Clin. Oncol. 2004;22 (24): 4867-8. doi:10.1200/JCO.2004.09.959 - Pubmed citation
- 4. Curé JK, Vattoth S, Shah R. Radiopaque jaw lesions: an approach to the differential diagnosis. Radiographics. 2012;32 (7): 1909-25. Radiographics (full text) - doi:10.1148/rg.327125003 - Pubmed citation