Predictors of Osteoradionecrosis Following Radiation Therapy for Head and Neck Squamous Cell Carcinoma: The Role of Dental Management and Disease Severity

Background: Osteoradionecrosis (ORN) is a debilitating complication of radiation therapy (RT) for head and neck squamous cell carcinoma (HNSCC). The protective role of preradiation dental clearance (PRDC) and the risk associated with postradiation dental treatment (PRDT) remain incompletely defined. Methods: The authors performed a retrospective cohort study of patients with HNSCC who completed head and neck RT at a single institution between March 2000 and January 2024. Demographic, oncologic, surgical, radiation, and oral and dental variables were collected. The primary outcome was ORN. Multivariable logistic regression was used to evaluate independent predictors of ORN, and patients were further stratified by combined PRDC/PRDT status. Results: Among 462 patients, 47 developed ORN (10.2%). PRDC was documented in 182 patients (39.4%) and PRDT in 88 patients (19.0%). ORN rates were similar among patients with and without PRDC (10.4% versus 10.0%, P =0.88) but were higher among patients who underwent PRDT (23.9% versus 7.0%, P <0.001). On multivariable analysis, PRDC was not associated with ORN development ( P =0.474), whereas PRDT, smoking history, and free fibula flap (FFF) reconstruction were independent predictors (all P <0.05). In subgroup analysis, ORN incidence was highest among patients who underwent PRDT regardless of PRDC status. PRDC was independently associated with higher odds of PRDT ( P =0.008) but was not associated with delayed RT initiation. Conclusions: PRDC was not associated with reduced ORN risk in this cohort. ORN was most strongly associated with PRDT, smoking history, and FFF reconstruction, supporting risk-stratified dental surveillance, smoking cessation, and careful avoidance of traumatic post RT dental interventions when clinically feasible.