Risk factors for and the role of dental extractions in osteoradionecrosis of the jaws: A national‐based cohort study

Background The purpose of this study was to investigate the risk factors, especially the use of certain drugs and the dental procedures, for osteoradionecrosis of the jaw (ORNJ) in patients with head and neck cancer undergoing irradiation as their primary treatment. Methods The cohort was composed of 23,527 patients with head and neck cancer. Cox proportional hazard models were used for risk factors analysis. Results The overall incidence of ORNJ is 3.93 per 100 person-years. Buccal cancer carried the highest ORNJ risk. The use of steroids had a protective effect. Preradiotherapy extraction posed no excess risk, whereas postradiotherapy extraction was associated with gradually increased risk of ORNJ over time that peaked at 4 to 5 years. Conclusion ORNJ warrants life-long attention for head and neck cancer survivors. The present study strongly confirms the role of preirradiation dental extractions. Meanwhile, efforts should be made to prevent posttreatment extractions, especially in the first posttreatment 4 years. © 2017 Wiley Periodicals, Inc. Head Neck 39: 1313–1321, 2017