A preliminary clinical study of segmental mandibulectomy on medication-related osteonecrosis of the jaw

Background/purpose: Recently, many reports have recommended surgical treatment for medication-related osteonecrosis of the jaw (MRONJ). However, MRONJ is more likely to occur in older patients with poor general condition and often necessitates extensive surgery, such as segmental mandibulectomy. The purpose of this study was to investigate treatment outcome of patients with MRONJ undergoing segmental mandibulectomy. Materials and methods: This retrospective study included 137 patients with medicationrelated osteonecrosis of the lower jaw who underwent surgical treatment at our hospital between 2011 and 2019. A total of 168 surgeries (155 marginal mandibulectomies and 13 segmental mandibulectomies) were performed. The relationship between clinical and imaging factors and the treatment outcome was investigated in the segmental mandibulectomy cases. Results: Preoperative computed tomography (CT) showed osteolytic lesions in 13/13, periosteal reaction (PR) in 12/13, and osteosclerosis in 12/13 cases of segmental mandibulectomy. On postoperative CT, no residual osteolytic lesion and PR were noted, and 9 cases showed osteosclerosis. Twelve patients (92.3%) undergoing segmental mandibulectomy had complete healing, whereas the cure rate of those undergoing marginal mandibulectomy was 104/155 (67.1%). One patient with relapse after segmental mandibulectomy showed healing after an additional resection. In the patients who underwent segmental mandibulectomy, clinical symptoms, such as pain and purulent discharge, disappeared, and oral intake was possible. Conclusion: Segmental mandibulectomy is a treatment option for end-of-life care of refractory MRONJ, because it can eliminate clinical symptoms early. When performing segmental mandibulectomy, the area of the osteolytic lesion and periosteal reaction needs to be included. (c) 2021 Association for Dental Sciences of the Republic of China. Publishing services by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons. org/licenses/by-nc-nd/4.0/).