[Bisphosphonate-associated osteonecrosis of the jaw]

Abstract

Background: Bisphosphonates (BP) are widely used in patients with osteoporosis or malignant tumors with bony metastases such as breast cancer and plasmocytoma because of their potency to affect osteoclasts and bone resorption. Osteonecrosis of the jaw (ONJ) has been described as a potential side effect since 2003. After a review of the literature we present results of a questionnaire, which was sent to departments of oral and maxillofacial surgery (OMFS) in German-speaking countries.

Material and methods: We present 349 patients from the literature, 54 patients from the departments of OMFS and 19 cases from our own department. These patients ware analyzed depending on their disease, their medication, localization of the affected area, histological signs and therapeutic outcome.

Results: Of 73 patients, 68 (93%) were treated with pamidronate or zoledronate; 69 (94%) patients suffered from malignant diseases, 3 (5%) had osteoporosis, and 1 (1%) had Paget's disease. In 57 (78%) patients the ONJ affected the mandible, in 12 (16%) the maxilla and in 4 (5%) both jaws. A previous tooth extraction was reported in 38 (52%) patients, and in 35 (48%) ONJ occurred spontaneously. Histological findings were similar to osteomyelitis with a high number of actinomyces colonies. Nine (12%) patients received non-surgical treatment only, 52 (71%) patients underwent minor surgical procedures (e. g. decortication) and 19 (26%) patients underwent marginal or segmental resection of the jaw. Considering all treatment modalities, healing was achieved in 55; the most effective was marginal and segmental resection (88%).

Discussion: Though millions of patients receive BP treatment only a few suffer from ONJ. The incidence in cancer patients with pamidronate and zoledronate therapy is 4%-10%. Because of the similarity to "phossy jaw", seen in patients dealing with white phosphorus in the nineteenth century, some authors call the new entity "bis-phossy jaw". As the pathogenesis of ONJ is not clear we recommend that the descriptive term bisphosphonate-associated osteonecrosis should be used. Bone resection and safe soft tissue closure is the treatment of choice. We recommend systematic dental care for patients receiving BP medication. Information exchange between oncologists, oral and maxillofacial surgeons and dentists is important.