Chunui Lee

Medication-related osteonecrosis of the jaw (MRONJ) has chiefly involved patients receiving medications for the treatment of bone-related malignancies. The surgical methods are now cautiously recommended as the treatment option for MRONJ. The purpose of this retrospective study was to report new bone formation and examine possible factors influencing spontaneous bony bridge formation by using an R-plate for reconstruction without any graft material after segmental mandibulectomy in patients with MRONJ. A cohort of 54 patients who underwent mandibulectomy between 2017 and 2022 by a single operator were included. Of them, 14 MRONJ patients (12 females and 2 males) were selected based on the inclusion criteria. Data on new bone formation, bony bridge formation, R-plate fracture, patient age, and type and duration of medication were collected. The mean age of the patients was 74.8 ± 9.3 years. All patients showed new bone formation, and 71.4% showed bony bridge formation within a year after surgery. The older the patient, the lower was the tendency for bony bridge formation in the defect (p = 0.035). Statistical analysis was performed using Fisher’s exact test. Preservation of the periosteum might be one of the most important contributing factors to new bone formation, serving as an optimal treatment option for reconstruction after segmental mandibulectomy in patients with MRONJ.