Osteonecrosis of the jaws and bisphosphonate treatment in cancer patients

Osteonecrosis of the jaws is described as an intraoral complication after administration of intravenous nitrogen-containing bisphosphonates. In a retrospective study, patients with osteonecrosis of the jaws after bisphosphonate treatment were evaluated with regard to diagnostic investigations and therapeutic management.

Seventeen patients with osteonecrosis of the jaws after bisphosphonate treatment who were referred to our department between July 2004 and June 2005 were included in this study. Computer tomography, magnetic resonance imaging, scintigraphy, bacteriology and biopsy were used in diagnostic evaluation. All patients were treated surgically.

The reasons for bisphosphonate treatment were multiple myeloma in 12 patients, breast cancer with bone metastasis in four patients and histiocytosis X in one patient. Five patients had received intravenous pamidronate and 12 patients zoledronic acid. The median number of treatment cycles for pamidronate was 36 times (range 4-100) in 38 months (range 4-100). Zolendric acid was given 23.5 times (range 5-39) in 26 months (range 5-39). Nine patients had a lesion in the mandible, eight in the maxilla. Clinical symptoms were exposed bone, pain and local inflammation of the mucosa. Computer tomography showed sclerotic areas in the osteonecrosis zone. The biopsy did not show a metastatic lesion. Sequestrectomy and decortication was adequate in the follow-up.

Nitrogen-containing bisphosphonates appear to be associated with the risk of developing osteonecrosis of the jaws. To reduce this risk, patients should be evaluated by a dentist before beginning treatment with intravenous bisphosphonates.