Factors associated with osteonecrosis of the jaw among bisphosphonate users

BACKGROUND: Bisphosphonates are medications that impact bone reformation by inhibiting osteoclast function. Osteonecrosis of the jaw has been reported among patients receiving these medications. It is unclear if the risk factors associated with osteonecrosis of the jaw among cancer patients taking bisphosphonates also are possible risk factors among patients receiving these medications for other indications. METHODS: A systematic review search strategy was used to identify cases of osteonecrosis of the jaw among patients taking bisphosphonates for an indication other than cancer to identify potential contributing factors. Data were analyzed according to previous models to develop a more expanded model that may explain possible mechanisms for the development of osteonecrosis of the jaw among patients without cancer. RESULTS: Ninety-nine cases of osteonecrosis of the jaw were identified among patients who were prescribed a bisphosphonate for an indication other than cancer. These cases included 85 osteoporosis patients, 10 patients with Paget's disease, 2 patients with rheumatoid arthritis, 1 patient with diabetes, and 1 patient with maxillary fibrous dysplasia. The mean age was 69.4 years, 87.3% were female, and 83.3% were receiving oral, but not intravenous, bisphosphonates. Of the 63 patients reporting dental care information, 88.9% had a dental procedure before the onset of osteonecrosis of the jaw. Of all cases providing medical information, 71% were taking at least one medication that affects bone turnover in addition to the bisphosphonate, and 81.3% reported additional underlying health conditions. CONCLUSIONS: The case details suggest a multiplicity of factors associated with this condition and provide the foundation for a model outlining the potential mechanism for the development of osteonecrosis of the jaw among patients taking bisphosphonates for an indication other than cancer. (C) 2008 Elsevier Inc. All rights reserved.