The bisphosphonates-osteonecrosis of the jaws. Prevention, diagnosis, and treatment

Bisphosphonates (BPs) are an important class of drugs that are useful in the treatment of certain metabolic and oncologic diseases of the skeletal system. Their efficacy in the treatment and palliative care of patient with these diseases is indisputable, but avascular osteonecrosis of the jaws (B-ONJ) has recently been reported as an adverse effect of intravenous BP therapy and with prolonged therapy with oral BPs. MATERIALS AND METHODS. We reviewed the most recent scientific literature on B-ONJ in an attempt to characterize this adverse event from an epidemiological point of view and to elaborate guidelines for its diagnosis, prevention, and treatment. RESULTS. B-ONJ usually arises in the mandible, in most cases at the level of mylohyoid line; involvement of the upper jaw is less common. It normally occurs after a dental extraction or other types of oral surgery, but it can also develop spontaneously. In cases of the latter type, systemic risk factors (e.g., comorbidities, concomitant therapies), or local pathological/anatomical conditions of the oral cavity play an important role. For patients without identified risk factors, intravenous BP therapy is associated with an estimated incidence of B-ONJ between 0.8 and 1.15%; figures may be as high as 9.1% if these patients undergo dentoalveolar surgery. In patients treated with oral BF, the incidence rate ranges from 0.01 to 0.04% and increases to 0.09%-0.34% after extractions. None of the treatments currentIy used to treat B-ONJ are completely effective and predictable, so prevention is essential for patients receiving BPs. Oral and dental risk factors should be eliminated before BP therapy begins, and this requires close collaboration by the patient's physician and dentist. After BP therapy has been started, there are relative contraindications to dentoalveolar surgery, and only unavoidable procedures should be performed. If B-ONJ develops, the best clinical results are achieved with combined treatment that includes antibiotics, antiseptic mouthwashes, surgical removal of necrotic bone, surgical debridement, biostimulation with low-level laser therapy and ozone-therapy. CONCLUSIONS. B-ONJ is an uncommon but potentially serious complication of BP therapy. It can produce significant morbidity and severely diminish the quality of life. The prognosis appears poor even when appropriate treatment is provided. Since the first cases of B-ONJ have been reported, considerable advances have been made in our knowledge of the pathogenesis of this disease and its risk factors, diagnosis, prevention, therapy, and management of the complications.