RÉSUMÉ
BACKGROUND AND OBJECTIVES: Osteoradionecrosis (ORN) of the mandible is one of the most serious complications following radiotherapy for oral and oropharyngeal cancer. However, the predisposing factors and clinical course of ORN are variable and its proper management is currently undetermined. The objective of this study is to review our ORN cases and evaluate the treatment methods. PATIENTS AND METHODS: We retrospectively reviewed 57 cases of oral and oropharyngeal cancers, where patients received combined surgery and radiotherapy from 1990 to 1998. Osteoradionecrosis occurred in 5 cases, and we evaluated the predisposing factors, clinical course and results of treatments. Four patients were treated with radical sequestrectomy and open reduction of mandible. Of these four patients, three received the combined treatment with hyperbaric oxygen (HBO) therapy, and one received the conservative treatment. RESULTS: Four ORN cases occurred at the lateral mandibulotomy site and one case arose at the opposite mandibular body unrelated to osteotomy. The interval between ORN and radiotherapy was so variable as 3 to 140 months. Four patients were successfully treated with the combined surgical and HBO therapies (3 cases) or with the conservative treatment (1 case). The remaining case could not be controlled by surgical treatment without HBO. CONCLUSION: Osteoradionecrosis usually occurred at lateral mandibulotomy sites, especially combined with sagittal partial mandibulectomies. We recommend that lateral mandibulotomies should, whenever possible, be avoided if the radiotherapy is planned postoperatively. And the patients who received radiotherapy at the mandible should be observed for osteoradionecrosis for long time. Our treatment results suggest that a combined surgery with HBO therapy can be a primary treatment modality for ORN.