Osteoradionecrosis After Mandibulotomy and Marginal Mandibulectomy in Patients With Oral Cancer.

Objectives Osteoradionecrosis is one of the most severe complications in patients with head and neck cancer, which is characterized by persistent exposed and devitalized bone without proper healing after radiation. The extent to which mandibulotomy and marginal mandibulectomy influence the occurrence of osteoradionecrosis remains unclear. This study evaluated the incidence and risk factors for developing osteoradionecrosis of the mandible after oral cancer treatments. Methods A retrospective study was performed to analyze medical records of patients who underwent surgery and postoperative radiotherapy for oral cancers from 2009 to 2019 at a tertiary care hospital. Patient characteristics, incidence, and risk factors for developing osteoradionecrosis were reviewed. Comparisons between continuous and categorical data were performed using t-test and Chi-squared test. Cox regression analysis was used to assess the association between factors and the development of osteoradionecrosis. Results Among the 61 patients included in the study, osteoradionecrosis of the mandible occurred in 9 of 32 (28.1%) patients who underwent mandibular surgery during oral cancer resection (marginal mandibulectomy and/or mandibulotomy) and 2 of 29 (6.9%) patients without mandibular surgery. The development of osteoradionecrosis was significantly associated with performing mandibular surgery (hazard ratio 4.64, 95% confidence interval: 1.002, 21.5) and HIV infection (hazard ratio 8.53, 95% confidence interval: 2.2, 33.3). In the subgroup analysis of mandibular surgery, the development of osteoradionecrosis significantly increased in patients undergoing mandibulotomy (hazard ratio 6.62, 95% confidence interval: 1.3, 34.8) but not in patients undergoing marginal mandibulectomy (hazard ratio 3.56, 95% confidence interval: 0.6, 22.0). The analysis also showed that concurrent chemoradiation, radiation doses ≥ 60 Gy, and smoking were potential risk factors for the development of osteoradionecrosis, but none of these factors were statistically significant. Conclusion Our findings suggest that mandibular surgery is a significant risk factor for the development of osteoradionecrosis in patients with oral cancer. Further studies including larger population sizes are required to verify these findings.