Bisphosphonate-related osteonecrosis of the jaws: A review of 34 cases and evaluation of risk

Introduction: The purpose of this study was to identify factors that influence bisphosphonate-related osteonecrosis of the jaws (BRONJ). Patients and methods: Patients undergoing treatment for BRONJ (n = 34) were evaluated. Sex, age, underlying diagnosis, type of bisphosphonate (BP), duration and route of administration, location of osteonecrosis, clinical symptoms, Actinomyces colonisation, treatment and outcome were recorded. Symptom onset was analysed with respect to BP potency and cumulative dose. Results: Underlying diagnoses indicating BP-treatment included multiple myeloma, breast carcinoma, prostate carcinoma and osteoporosis. In 31 patients, BRONJ was preceded by tooth extraction, root apicotomy, ill-fitting dentures, cystenucleation, implant insertion or trauma; in 3 patients, the precipitating event was not identified. Actinomyces colonisation was observed in 18 patients (53%). The occurrence of BRONJ was not directly related to BP dose or potency. More women with multiple myeloma had BRONJ than did males. BRONJ was observed in osteoporotic patients treated with both corticosteroids and BPs. Conclusions: BRONJ was not primarily associated with BP potency or dose. Factors that increased the risk of osteonecrosis were female sex, oral surgery and corticosteroids plus intravenous or oral BP administration. BP deposition in the jaw bones might enhance BRONJ by promoting bacterial colonisation; however, this hypothesis requires more study. (C) 2009 European Association for Cranio-Maxillo-Facial Surgery