Settling the minimum gap between dental extraction and the start of head and neck radiotherapy

The evidence. A 2026 meta-analysis of eight retrospective cohorts (47,527 people with head and neck cancer, 2,863 cases of osteoradionecrosis) found no overall association between the extraction-to-radiotherapy interval and osteoradionecrosis (odds ratio 0.99, 95 per cent confidence interval 0.67 to 1.47), with very high heterogeneity (I² 92 per cent). In Western populations, starting radiotherapy within 7 days of extraction was associated with higher risk (odds ratio 3.07, 1.52 to 6.21), as was starting within 14 days (2.01, 1.10 to 3.68). A 2022 meta-analysis of seven studies (875 people treated with IMRT) found that extractions before IMRT were associated with less osteoradionecrosis than extractions after, but the prediction interval included no effect and the authors concluded the benefit was not proven, to be balanced against delay to cancer treatment.

The guideline. The ISOO-MASCC-ASCO guideline on osteoradionecrosis (2024) is the current international standard; only its abstract could be read for this record, so whether it states an interval is not reported here.

What is unknown. Every study is retrospective and none randomises the interval; how much delay to radiotherapy is acceptable for a given tumour is a separate question the dental studies do not address.