Influential factors related to osteoradionecrosis of the mandible in oral and maxillofacial cancer patients following radiotherapy

Objective: To identify risk factors associated with mandibular osteoradionecrosis (ORN) in oral and maxillofacial cancer patients following radiotherapty and to provide scientific basis for the etiological research and clinical prevention of mandibular ORN. Methods: A retrospective study was conducted in patients with oral and maxillofacial-head and neck cancer during the period from January 2013 to December 2015. Influential factors related to mandibular ORN were screened by single factor analysis, Lasso and Logistic regression analysis. Results: A total of 757 patients were analyzed, and the total incidence of mandibular ORN was 12.0%(91/757). There were 443 males and 314 females, aged (51.8±13.7) years. Thirty-five related factors were screened to 28 by single factor analysis. It was determined by Lasso regression analysis that, radiation doses (OR=1.135, P=0.034, 95%CI: 1.089-1.232), T classification (OR=2.586, P=0.001, 95%CI: 1.482-4.512), mandibular surgery (OR=9.101, P<0.001, 95%CI: 2.796-29.630), periodontitis (OR=6.089, P<0.001, 95%CI: 2.708-13.693), diabetes (OR=4.467, P=0.002, 95%CI: 1.705-11.704), tooth extraction after radiotherapy (OR=3.228, P=0.001, 95%CI: 1.640-6.350), dental caries (OR=2.911, P=0.009, 95%CI: 1.300-6.516), periapical periodontitis (OR=2.726, P=0.016, 95%CI: 1.209-6.145), smoking (OR=4.438, P=0.002, 95%CI: 1.702-11.571) and unilateral/bilateral radiotherapy (OR=2.225, P=0.028, 95%CI: 1.090-4.545) were significantly associated with developing mandibular ORN. Conclusions: Ten main risk factors for mandibular ORN were identified through the single center, large sample, retrospective analysis, which has a certain value for clinical prevention of mandibular ORN. Prospective, randomized controlled trials and long-term follow-up are still needed.