Osteoradionecrosis of mandible bone in patients with oral cancer--associated factors and treatment outcomes.

BACKGROUND The purpose of this study was to investigate factors associated with osteoradionecrosis (ORN) of the mandible bone in a large cohort of patients with oral cancer. METHODS We reviewed the medical records of patients with oral cancer and identified those with ORN of the mandible bone. Variables of patients with and without ORN were compared and associated factors were investigated by logistic regression model. RESULTS A total of 1692 patients were included in the final analysis and 105 patients (6.2%) developed ORN in the mandible bone. Primary site, including mouth floor, buccal mucosa, retromolar trigone, or gum, segmental mandibulectomy, and total radiation dose to the primary site ≥75 Gy were independent factors associated with ORN. After aggressive treatment using surgical intervention with/without hyperbaric oxygen, 93.3% of the patients healed completely. CONCLUSION Among patients with oral cancer after radiation, ORN is an uncommon and dreaded complication. Recognition of associated factors can help physicians to identify those at risk.