Bisphosphonate-induced osteonecrosis of the jaw: a medical enigma?

Bisphosphonates are used for the standard of care of patients with skeletal metastases and hypocalcemia of malignancy. Bisphosphonate-induced osteonecrosis (BION) is a serious complication. Clinically, BION presents as an area of exposed alveolar bone that occurs spontaneously or becomes evident following an invasive surgical procedure such as extraction of a tooth, periodontal surgery, apicoectomy, or oral implant placement. The mechanism by which bisphosphonates cause osteonecrosis is uncertain. There are no controlled trials to show a direct cause-effect relationship between bisphosphonates and osteonecrosis of the jaw. Oral bisphosphonate-induced necrosis is a rare clinical entity, less frequent, less aggressive, more predictable, and more responsive to treatment than IV forms of bisphosphonate-related osteonecrosis of the jaw. However, there have been reports of this complication with the less potent oral forms of bisphosphonates (0.007% to 0.01%). The morbidity of osteonecrosis of the jaw induced by IV bisphosphonates is significant, so prevention should receive prime importance. Patients should receive prophylactic dental examinations, and any necessary dental treatment before starting bisphosphonate therapy. Good communication among dentists, oral surgeons, physicians, and oncologists is of vital importance in providing care of these patients. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2009; 108: e1-e8)