Diagnosis and treatment of medication-related osteonecrosis of the jaws: a cohort study over 20 years

OBJECTIVE: To provide a comprehensive cohort profile of patients diagnosed with medication-related osteonecrosis of the jaw (MRONJ) in the Copenhagen ONJ Cohort-a 20-year longitudinal cohort. METHODS: This observational cohort study included all patients diagnosed with MRONJ at the Department of Oral and Maxillofacial Surgery, Copenhagen University Hospital, between January 1, 2005, and December 31, 2024. Demographic, disease-related, and treatment variables were prospectively recorded during clinical visits and retrospectively supplemented through review of medical records. Descriptive statistics were calculated, and subgroup comparisons were performed according to antiresorptive therapy (AR) exposure or underlying disease. RESULTS: A total of 934 patients were included. The mean age was 71.6 years (standard deviation ±10.8), and 693 (68.4%) were female. The most common indications for AR were osteoporosis, breast cancer, prostate cancer, and multiple myeloma. Conservative management was applied in 18.1% of patients, whereas 81.9% underwent surgical interventions. Tooth removal was identified as the most frequent triggering event of MRONJ (52.9%). Differences in demographics, comorbidities, and concomitant use of systemic corticosteroids, immunosuppressive agents, and antiangiogenic medications were observed across AR-dose groups. CONCLUSIONS: The Copenhagen ONJ Cohort provides robust insights into the epidemiology, risk factors, and management of MRONJ, supporting further investigation into the association between cumulative AR exposure and MRONJ development.