Abstract: Objective: To investigate the surgical treatment and efficacy of severe advanced medication-related osteonecrosis of the jaw (MRONJ). Material and Methods: Patients who underwent stage 3 MRONJ surgery in the Department of Oral and Maxillofacial Surgery, Nanjing Stomatological Hospital from January 2020 to January 2025 were included in this study. The basic clinical data, surgical methods and prognosis of the patients were collected and statistically analyzed. Results: A total of 64 patients (68 lesions) were included in this study, including 29 males and 35 females. 25 lesions were located in the maxilla and 43 lesions were located in the mandible. The primary disease was malignant tumor in 61 cases and osteoporosis in 3 cases. The medication history included zoledronic acid (n=29), denosumab (n=24), monotherapy (n=41) and combination therapy (n=23). The average duration of medication was 3.7±1.2 years. Subtotal maxillectomy was performed in 25 cases, of which 2 cases were treated with fenestration and drainage, and 4 cases were treated with buccal fat pad flap. 43 patients underwent segmental mandibular osteotomy, of which 38 patients used reconstruction titanium plate for jaw reconstruction, and the remaining 5 patients used the guide flange prosthesis to help restore the occlusal relationship after operation. The patients were followed up for 12-24 months, 55 patients achieved mucosal healing at the last follow-up, and the total cure rate was 85.94%. Conclusions: Surgical treatment of stage 3 medication-related osteonecrosis of the jaw can achieve good results. Various intraoperative repair methods can help the mucosa to achieve good primary healing.

Key words: medication-related osteonecrosis of the jaw, surgical treatment, buccal fat pad, reconstruction of jaw, prognosis