Osteoradionecrosis
Pronunciation: os-tee-oh-ray-dee-oh-neh-KROH-sis
Necrosis of bone within a previously irradiated field, most frequently involving the mandible, arising from radiation-induced compromise of bone vascularity and healing capacity.
Full Definition
Osteoradionecrosis (ORN) is a serious late complication of radiotherapy to the head and neck region in which irradiated bone, typically the mandible, becomes devitalised and fails to heal. Radiation damage to osteoblasts, osteoclasts, and the microvasculature renders the bone hypoxic, hypovascular, and hypocellular, impairing its capacity for repair. ORN may arise spontaneously or be precipitated by dental extraction or trauma within the radiation field. Staging systems such as the Marx and Notani classifications are referenced in clinical documentation and editors should render these eponyms with initial capitals. The term is written as a single unhyphenated word and must not be confused with 'osteonecrosis of the jaw' (ONJ), which is a distinct entity associated with antiresorptive drug therapy.
Usage
Usage note: Do not confuse with MRONJ (medication-related osteonecrosis of the jaw). The accepted abbreviation is ORN. Render staging system eponyms (Marx, Notani) with initial capitals.
In Context
- "Following radiotherapy for oropharyngeal carcinoma, the patient developed osteoradionecrosis of the mandible at the site of a previous extraction." — Maxillofacial oncology clinic letter
- "The Marx staging system was used to classify the severity of osteoradionecrosis prior to surgical debridement." — Multidisciplinary team meeting notes