MON-821 - Medication-Related Osteonecrosis of the Jaw after Therapy with Zoledronic Acid or Denosumab in Patients with Osteoporosis: A Colombian Case Series

Background: Medication-related osteonecrosis of the jaw (MRONJ) is a severe and uncommon adverse effect, clinically relevant, associated with the use of antiresorptive therapies for osteoporosis, with an estimated prevalence of approximately 0.01% to 0.03%. Despite its low frequency, delayed diagnosis may result in advanced disease and increased morbidity.

Objective: To describe the clinical characteristics, antiresorptive medication exposure ( zoledronic acid or denosumab), treatment duration, and management of individuals diagnosed with MRONJ in a single Colombian high complexity hospital between 2015 - 2025.

Methods: We conducted a retrospective case series including patients diagnosed with MRONJ according to the American Association of Oral and Maxillofacial Surgeons (AAOMS) criteria. Demographic data, comorbidities, type of antiresorptive agent, duration of treatment, AAOMS stage at diagnosis, radiological findings, and management strategy were analyzed descriptively. Continuous variables are reported as median and range, and categorical variables as frequencies and percentages.

Results: Seven individuals were included, all women, with a median age of 69 years (range: 56-81). All received antiresorptive therapy for osteoporosis prior to MRONJ diagnosis. Zoledronic acid was administered to four participants (57.1%), while three received denosumab (42.9%). The median duration of antiresorptive therapy was 36 months (range: 24–48). At diagnosis, three individuals were classified as AAOMS stage 1 (42.9%), one as stage 2 (14.3%), and three as stage 3 (42.9%). Radiological evaluation demonstrated osteolysis in all cases, with additional findings such as bone sequestration. Pain and signs of local infection or inflammation were reported for stages 2 and 3 (57.1%). Four individuals were managed conservatively (57.1%), while three (stage 3) were managed surgically (42.9%).

Conclusion: In this Colombian case series, MRONJ was observed in women with osteoporosis treated with zoledronic acid or denosumab after antiresorptive therapy. Most cases were diagnosed at advanced stages, which were associated with pain, radiological evidence of bone destruction, and the need for surgical management. These findings emphasize the importance of early detection, dental surveillance, and multidisciplinary management in patients receiving long-term antiresorptive therapy, while maintaining an individualized risk-benefit approach to antiresorptive therapy rather than unnecessary treatment discontinuation.

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