Dental Extractions Before Radiation Therapy and the Risk of Osteoradionecrosis in Patients With Head and Neck Cancer.

Importance: Patients with head and neck cancer undergo extraction of teeth with poor prognoses to minimize post-radiation therapy (RT) extractions, which are known to cause osteoradionecrosis (ORN). However, many patients are required to start RT before the extraction sites are completely healed. The role of pre-RT extractions in the development of ORN has been disputed in literature. Objective: To determine whether the timing of pre-RT dental extractions is associated with ORN development in patients with head and neck cancer. Design, Setting, and Participants: This retrospective cohort study was conducted at a single institution (Princess Margaret Cancer Centre, Toronto, Canada) between January 1, 2011, and January 1, 2018, and included 879 patients with head and neck cancer who underwent pre-RT dental extractions before curative RT of 45 Gy or greater. Patient demographic information and clinical characteristics (eg, primary cancer site, nodal involvement, chemotherapy, smoking status, dental pathology) were considered. Data analyses were performed from July to December 2022. Main outcomes and measures: Timing (number of days) from dental extractions to RT start date and pre-RT extractions categorized as healed, minor bone spicules (MBS), or ORN. Results: The study population consisted of 879 patients with a median (range) age of 62 (20-96) years, with 685 men (78%) and 194 women (22%). Of these, 847 (96.3%) healed from pre-RT dental extractions, 16 (1.8%) developed MBS, and 16 (1.8%) developed ORN. The median (range) time in number of days from pre-RT extraction(s) to start of RT was 9 (0-98) days in the healed cohort, 6 (3-23) days in the MBS cohort, and 6 (0-12) days in the ORN cohort. There was a large difference in the timing of pre-RT extractions between the healed and the MBS cohorts (mean 11.9 vs 7.4 days to radiation; difference 4.4; 95% CI, 1.5-7.3), and the healed and the ORN cohorts (mean 11.9 vs 7.1 days; difference 4.8 days; 95% CI, 2.6-7.1). Conclusion: The findings of this retrospective cohort study suggest that there was an important association between the timing of pre-RT dental extractions and ORN when extractions occurred within 7 days of the RT start date. Despite this, ORN after pre-RT extractions is relatively rare. These findings indicate that patients with head and neck cancer who are to undergo RT should not delay treatment for extractions when it might compromise oncologic control.