A population based study of multiple myeloma patients with medication-related osteonecrosis of the jaw

Objective. Medication-related osteonecrosis of the jaw (MRONJ) is a rare complication of antiresorptive or antiangiogenetic therapy that manifests as an exposed bone with clinical signs of infection, persisting for more than 8 weeks, without history of radiation therapy or metastases to the jaws. The aim of the study was to describe the incidence, risk factors, staging process and clinical course of MRONJ in patients with multiple myeloma (MM). Materials and methods. We retrospectively analyzed all (126) newly diagnosed MM patients at Riga East Clinical University Hospital (Riga. Latvia) from June 2014 to June 2017. Results. Among 88 MM patients treated with bisphosphonates (BP), 6 (6.8%) patients de-veloped MRONJ. All six patients received intravenous nitrogen-containing BPs. The average time until MRONJ manifestation was under two years. For our patients the severity of MRONJ was stage I in two, stage II in three, and stage III in one patient. Five patients had MRONJ of mandibula and one of maxilla. All patients with MRONJ had undergone a dental extraction or a trauma before the development of MRONJ. Conclusion. We found that MRONJ correlated with the patient’s age. The average time until MRONJ manifestation in reserach group is 2 years. One of triggerring MRONJ factors are tooth extraction or trauma.