Bisphosphonate (zoledronic acid)-induced osteonecrosis of the jaw

OBJECTIVE: The use of bisphosphonates (zoledronic acid) in the treatment of metastatic bone disease has been raised during recent years. The purpose of this treatment is mainly to reduce skeletal-related events, e.g. pain and pathological fractures. The aim of this study was to report the incidence of bisphosphonate-related osteonecrosis of the jaw (ONJ). MATERIAL AND METHODS: All patients treated with bisphosphonates during a 5-year period (2003-2007) were reviewed. RESULTS: Fifty-three patients, median age 69 years (range 56-81 years) were treated with bisphosphonates during the period. Fifty-one patients had hormone-refractory metastatic prostate cancer and two women had metastatic renal cell carcinoma. During this 5-year period, 686 treatments with bisphosphonates were administrated. The average treatment duration was 14 months (range 1-40 months) with administration of 4 mg of bisphosphonates every 4 weeks. Two cases of ONJ were registered. In the first case, the patient developed spontaneous osteonecrosis, whereas the second patient developed symptoms after a dental procedure. Since the initiation of a routine maxillofacial examination before treatment with bisphosphonates, no ONJ has been seen. CONCLUSION: ONJ is a rare but a very serious complication in relation to treatment with bisphosphonates. To decrease the incidence of ONJ, a maxillofacial examination could be performed in all patients before treatment with bisphosphonates.