Osteonecrosis of the jaw: an update and review of recommendations

Abstract

Bisphosphonates have had a very positive impact as therapeutic agents for cancer and osteoporosis, but have also been associated with osteonecrosis of the jaw (ONJ) which has emerged as an idiosyncratic oral complication. Bisphosphonate-associated ONJ has generated wide attention despite its considerably rare occurrence. Many speculations exist as to why bisphosphonates may increase the incidence of ONJ. The American Society for Bone and Mineral Research established a task force on bisphosphonate-associated ONJ and recently released a summary report of their findings. A case definition delineated a confirmed case of ONJ as 'an area of exposed bone in the maxillofacial region that did not heal within 8 weeks after identification by a health care provider, in a patient who was receiving or had been exposed to a bisphosphonate and had not had radiation therapy to the craniofacial region'. Treatment recommendations have been developed by the American Dental Association, the American Association of Oral and Maxillofacial Surgeons and the American Society for Bone and Mineral Research. Considering the scientific evidence, little is known about the true incidence and pathophysiology, and many questions persist. New epidemiologic studies are surfacing and attempts to ameliorate the condition may shed light on the likely complex etiology. The bones of the oral cavity provide a unique environment relative to blood flow, oral microbiota, bone structure and function. Although little is known of the mechanisms and course of ONJ, even less is known about the spectrum of issues of altered healing that could fall short of defined ONJ.