Osteonecrosis of the jaw in multiple myeloma patients: clinical features and risk factors.

To describe the clinical, radiologic, and pathologic features and risk factors for osteonecrosis of the jaw (ONJ) in multiple myeloma (MM) patients. A retrospective review of 90 MM patients who had dental assessments, including 22 patients with ONJ. There were 62 men; the median age was 61 years in ONJ patients and 58 years among the rest. Prior MM therapy included thalidomide (n = 67) and stem-cell transplantation (n = 72). Bisphosphonate therapy included zoledronate (n = 34) or pamidronate (n = 17) and pamidronate followed by zoledronate (n = 33). Twenty-seven patients had recent dental extraction, including 12 patients in the ONJ group. Median time from MM diagnosis to ONJ was 8.4 years for the whole group. Patients usually presented with pain. ONJ occurred posterior to the cuspids (n = 20) mostly in the mandible. Debridement and sequestrectomy with primary closure were performed in 14 patients; of these, four patients had major infections and four patients had recurrent ONJ. Bone histology revealed necrosis and osteomyelitis. Microbiology showed actinomycetes (n = 7) and mixed bacteria (n = 9). More than a third of ONJ patients also suffered from long bone fractures (n = 4) and/or avascular necrosis of the hip (n = 4). The variables predictive of developing ONJ were dental extraction (P = .009), treatment with pamidronate/zoledronate (P = .009), longer follow-up time (P = .03), and older age at diagnosis of MM (P = .006). ONJ appears to be time-dependent with higher risk after long-term use of bisphosphonates in older MM patients often after dental extractions. No satisfactory therapy is currently available. Trials addressing the benefits/risks of continuing bisphosphonate therapy are needed.