Factors predictive of severity of osteoradionecrosis of the mandible.

Background: An analysis of risk factors predictive of severe mandibular osteoradionecrosis (ORN) is needed to aid prophylaxis and management of this condition.

Methods: We retrospectively analyzed 46 patients diagnosed between June 2002 and March 2009: 93% had mandibular ORN, which was staged 0 to III (Store and Boysen). Patient, tumor, treatment-related, and other variables were analyzed for association with mandibular ORN severity.

Results: Oral or oropharyngeal tumors comprised 85% of our primary tumors, 80% were stage IV, and 91% were squamous cell carcinomas. Most patients (87%) received 3-dimensional (3D) conformal radiation therapy (RT), with 60 Gray (Gy) median dose; 28% and 72% received primary and adjuvant RT, respectively; 78% received chemotherapy, mostly concurrent (97%) and platinum-based (96%). Median time to development of ORN was 7.5 months. White ethnicity and secondary infection correlated significantly with stage III mandibular ORN (p = .038, p = .0007, respectively). Advanced age, stage IV, RT dose, post-RT, and lack of pre-RT dental extractions appeared predictive of severe mandibular ORN.

Conclusions: The above-cited factors are predictive of severity and can potentially guide prophylaxis and management.