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.