Medication-related osteonecrosis of the jaw in Northern Thailand: A one-year cohort study of risk factors, incidence, and healing outcomes.

Background: Medication-related osteonecrosis of the jaw (MRONJ) is a serious complication of antiresorptive and antiangiogenic therapies. Identifying its incidence and risk factors is vital for prevention and management. Objective: To identify clinical and pharmacological factors associated with healing outcomes in patients with MRONJ who receiving antiresorptive or antiangiogenic therapy treated at a single center over one-year analysis period. Additionally, we examined the healing outcome and its association with MRONJ stage and anatomical location. Methods: This single-center cohort study, combining retrospective baseline data collection with prospective longitudinal follow-up over one year in Northern Thailand. Patient demographics, medication history, clinical features, and treatment outcomes were analyzed. Results: Seventy-four patients (79.73 % female; mean age 72.07 ± 10.78 years) with 205 sites were analyzed. The overall MRONJ prevalence was 22.44 %, highest among patients with bone metastasis (85.71 %) and multiple myeloma (23.53 %). One-year incidence reached 23.46 %, with cancer patients showing the highest incidence (100 %). Tooth extraction was the leading local risk factor (71.74 %). Overall healing rate was 67.39 %, with better outcomes in stage 1 (77.78 %) and stage 2 (68.00 %) compared to stage 3 (0 %). In stages 1 and 2, univariable analysis showed stage 1 had higher odds of healing (OR: 1.84; 95 % CI: 0.53-6.41), and multivariable analysis confirmed this trend (adjusted OR: 3.51; 95 % CI: 0.16-76.4), though neither was statistically significant. Conclusion: MRONJ prevalence and incidence remain substantial in high-risk populations. Better healing was observed in early-stage lesions, emphasizing the importance of early detection and timely intervention to improve clinical outcomes.