High Incidence of Mandibular Osteoradionecrosis After Radiotherapy for Oral Cavity: Time for Rebalancing Risks and Benefits.

AIMS: Limited evidence exists on the incidence of osteoradionecrosis (ORN) specifically for oral cavity (OC) cancer alone. The primary objective of this study was to determine the incidence of ORN for each subsite of the OC. The secondary objective was to analyse the risk factors for ORN development.

MATERIALS AND

METHODS

Between 2010 and 2021, a total of 2517 head and neck cancer patients underwent radical or adjuvant radiotherapy (RT) at our centre. Of these, 254 patients with an OC primary cancer were identified and were included in this analysis.

RESULTS

Of the 254 patients, ORN developed in 57 patients (22.4%). Subsite analysis showed the following incidence: floor of mouth 21/64 (32.8%), retromolar trigone 11/46 (23.9%), lower gum 8/25 (32.0%), tongue 14/109 (12.8%) and buccal mucosa 3/10 (30.0%). In univariable analysis, any surgical intervention involving the mandible as well as dental extraction after RT were identified as significant risk factors for ORN development (P < .05). In multivariable analysis, dental extraction after RT (P < .001), rim resection as a part of the primary treatment (P = .027), and ipsilateral neck irradiation (P = .045) were confirmed as significant risk factors.

CONCLUSION

This study, focusing exclusively on ORN of the OC, has revealed unexpectedly high rates of ORN at 22.4%, with certain subsites such as floor of mouth having an incidence of 32.8%. The authors recommend that postoperative RT for OC cancers should be carefully evaluated, weighing the potential benefits against the possible risks of morbidity.