[Bisphosphonate-associated osteonecrosis of the jaw]

Intravenous application of bisphosphonates (BP) represents an established therapeutic strategy of tumor-associated bone metastasis and severe hypercalcemia. Patients can develop osteonecrosis of the jaw (ONJ) as a side effect of this therapy. The diagnosis of ONJ is based on three criteria: a) patients have been or are currently treated with BP; b) a deficiency in wound healing, which is in 70-80% associated with necrotic alveolar bone, characteristically exposed, is present for at least 8 weeks and c) no radiotherapy of the head and neck was performed. The suppression of bone turnover, concomitant with high functional load of the alveolar bone, and the subsequent accumulation of microfractures are considered the main pathologic factors of this disease. The cumulative incidence of ONJ lies approximately between 1 and 10% in oncologic patients, being associated with the antiresorptive potency and the respective molecular structure of the BPs. Patients with multiple myeloma develop ONJ more frequently than patients with other oncological diseases such as metastasizing breast- and prostate cancer, a fact that may also be due to the higher transfusion/injection frequency of BP in these patients. Dental treatment strategies are responsible for the occurrence of ONJ in approximately 80% of cases. Based on a clinical staging, patients can be grouped into three categories and should receive the corresponding treatment regime. Prospective clinical studies are required for a better understanding of etiology and pathogenesis of ONJ to make treatment, risk estimation and prognosis of ONJ more accurate.