Osteoradionecrosis After Mandibulotomy and Marginal Mandibulectomy in Patients With Oral Cancer

Abstract

ObjectivesOsteoradionecrosis 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. MethodsA 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. ResultsAmong 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. ConclusionOur 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.

Invited Commentary from the Authors of: Chiu TH, et al. A Comparison Study of Outcomes and Complications Between Marginal Mandibulectomy With or Without Additional Mandibulotomy in Tongue Cancers

“…It was overassertive to expand the interpretation of the results from our descriptive statistics by simply enlarging the sample size through simulation and claiming those hypothesized results to be meaningful. We thought Somay et al misunderstood the results described in the Wongmanee's study 6 . There was in fact no conflict about the subgroup analysis of mandibular surgery between our study and Wongmanee's.…”

“…We thought Somay et al misunderstood the results described in the Wongmanee's study. 6 There was in fact no conflict about the subgroup analysis of mandibular surgery between our study and Wongmanee's. The hazards ratios of ORN significantly increased in patients undergoing mandibulotomy (hazards ratio, 6.62; 95% confidence interval, 1.3-34.8) but not in marginal mandibulectomy (hazards ratio, 3.56; 95% confidence interval, 0.6-22.0), both referencing to the "no mandibular surgery" group.…”

“…The hazards ratios of ORN significantly increased in patients undergoing mandibulotomy (hazards ratio, 6.62; 95% confidence interval, 1.3–34.8) but not in marginal mandibulectomy (hazards ratio, 3.56; 95% confidence interval, 0.6–22.0), both referencing to the “no mandibular surgery” group. Based on the actual data demonstrated in their Table 3, 6 there will also be no significant increase of ORN ( P = 1.000, Fisher exact test) when comparing the rates in the marginal mandibulectomy alone (27.3%, 3/11) and combined marginal mandibulectomy and mandibulotomy (16.7%, 1/6) groups.…”

Letter to the Editor: Comment on Chiu TH, et al. A Comparison Study of Outcomes and Complications Between Marginal Mandibulectomy With or Without Additional Mandibulotomy in Tongue Cancers (Ann Plast Surg. 2023;90(1 suppl 1):S37–S43)

“…This finding is critical because it pictures how crucial power analysis and the sample size are in these kinds of studies. As a clinical proof, in the subgroup analysis of mandibular surgery reported recently by Wongmanee and Chotipanich, 5 the development of ORN 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). Hence, Chiu and colleagues' 1 study does not seem to have the statistical power to detect the precise impact of mandibular surgery type on the ORN risk, a common nuisance in retrospective studies.…”