Bisphosphonate-related osteonecrosis of the jaws: an update on clinical, pathological and management aspects

Bisphosphonate-related osteonecrosis of the jaws (BRONJ) is mainly observed in patients with multiple myeloma and bone metastasis from solid tumors receiving iv bisphosphonate therapy. The reported incidence of BRONJ is significantly higher with the iv preparations zoledronic acid and pamidronate while the risk appears to be minimal for patients receiving oral bisphosphonates. Currently available published incidence data for BRONJ are based on retrospective studies and estimates of cumulative incidence range from 0.8 to 12%. The mandible is more commonly affected than the maxilla (2:1 ratio), and 60-70% of cases are preceded by a dental surgical procedure. The signs and symptoms that may occur before the appearance of clinical evident osteonecrosis include changes in the health of periodontal tissues, non-healing mucosal ulcers, loose teeth and unexplained soft-tissue infection. Although the definitive role of bisphosphonates remains to be elucidated, the inhibition of physiologic bone remodeling and angiogenesis by these potent drugs impairs the regenerative capacity of the bone causing the development of BRONJ. Tooth extraction as a precipitating event is a common observation. The significant benefits that bisphosphonates offer to patients clearly surpass the risk of potential side effects; however, any patient for whom prolonged bisphosphonate therapy is indicated, should be provided with preventive dental care in order to minimize the risk of developing this severe condition. This article provides an update review of current knowledge about clinical, pathological and management aspects of BRONJ.