Bisphosphonate osteonecrosis (BON): unanswered questions and research possibilities.

Bisphosphonate osteonecrosis (BON) is a relatively recent adverse drug event that affects the oral cavity almost exclusively. It has been reported in individuals with metastatic breast, prostate, and lung cancer as well as in multiple myeloma. It has also been reported in a small subset of individuals who have been treated with bisphosphonate therapy for osteoporosis and Paget's disease of bone. Published studies to date have been characterized by relatively small sample sizes. Based on these studies, incidence appears to range between 0.1% and 11% depending on the population being studied and a number of other co-factors that have not been completely understood. The pathobiology of BON has not been fully elucidated and risk factors involved in the process need confirmation. Patients with this complication have altered quality of life and can suffer from discomfort and pain. Management is difficult and, while many treatment protocols have been proposed, at best they have only had partial success. This review of literature discusses a number of issues involving BON, with focus on the definition, possible association of BON and bisphosphonate therapy, pathobiology of BON and several additional research questions that need further investigation.