Association between dental extraction after radiotherapy and osteoradionecrosis: A multi-centre retrospective study

Objective: Radiotherapy (RT) carries a substantial risk for the development of osteoradionecrosis (ORN) of the jaw. This study was performed to investigate the relationship between dental extractions after RT and the development of ORN. Material and Methods: Thirty-two patients with head and neck cancer who underwent tooth extraction after RT were investigated for correlations between the development of ORN and various factors. Results: Postextraction ORN was diagnosed in 12 (12.1%) teeth of 9 patients. The RT dose against the site of tooth extraction was 62.0 and 37.4 Gy in the ORN and Non-ORN groups, respectively (p <.001). The duration from RT to tooth extraction was 41.2 and 28.2 months in the ORN and Non-ORN groups, respectively (p =.025). Tooth extraction was significantly associated with ORN in patients with a high RT dose against the site (odds ratio = 1.231) and a longer duration of time from RT (odds ratio = 1.084). Conclusions: Extraction of non-restorable teeth and those with a poor prognosis should not necessarily be postponed even when patients are undergoing RT. However, clinicians should pay special attention to postoperative management after tooth extraction in patients with a high RT dose and longer time from RT.