Osteonecrosis of the Jaw (ONJ)

Bisphosphonates are commonly prescribed to inhibit bone loss in patients with osteoporosis, as well as osteopenia, cancer, and Paget's disease of the bone. Recent news articles have addressed the possibility of a relationship between bisphosphonates and ONJ.

It is important to note that the risks for developing ONJ are much higher for cancer patients on intravenous bisphosphonate therapy (used to reduce bone pain, hypercalcemia of malignancy, and skeletal complications in cancer patients) than for patients on oral bisphosphonates (commonly used to treat bone loss from osteopenia or osteoporosis). In fact, 94% of published cases of ONJ are patients with multiple myeloma or metastatic carcinoma to the skeleton that are receiving IV, nitrogen-containing bisphosphonates (Woo SB et al. Ann Intern Med. 2006;144:753-761). This is most likely due to the fact that bisphosphonates administered intravenously are taken up much more readily by bone than those administered orally. Current evidence also shows that 60% of osteonecrosis cases occurred after dental surgical procedures, such as tooth extraction (Woo SB et al. Ann Intern Med. 2006;144:753-761).

The following articles provide a more in-depth look at ONJ and bisphosphonate use:

American Dental Association:
www.ada.org/prof/resources/topics/osteonecrosis.asp

National Osteoporosis Foundation:
www.nof.org/patientinfo/osteonecrosis.htm