Abstract: Objective: To report the surgical treatment process and efficacy of a patient diagnosed as stage 3 medication-related osteonecrosis of the jaw(MRONJ) with pathological fracture of the mandible, and to explore the clinical experience of segmental osteotomy without titanium plate repair reconstruction. Diagnosis and treatment: According to the definition of MRONJ and the proposed staging criteria of the American Association of Oral and Maxillofacial Surgeons(AAOMS), the patient was diagnosed definitively stage 3 of mandible. The surgical plan was made after the preoperative examination was completed. After communicating with patient, only segmental osteotomy of mandible was selected. After operation, a winged inclined guide plate was made to improve the occlusal function of the patient. Results: This case achieved the goal of recovery and functional reconstruction, and the patient was satisfied with the current treatment and functional recovery. Conclusions: For mandibular stage 3 patients who cannot tolerate complex general anesthesia surgery, segmental osteotomy alone and a winged inclined guide plate may be considered to improve occlusal relationship.

Key words: medication-related osteonecrosis of the jaw, pathological fracture, segmental osteotomy, winged inclined guide plate, function