Osteonecrosis of the Jaw Associated with Pamidronate Therapy.

BACKGROUND: Bisphosphonates, as a class of medication, fulfill an essential role serving to modify the natural history of bone disease associated with multiple myeloma and other neoplasms that infiltrate bone. They are also commonly used for the prevention and treatment of osteoperosis. Bisphosphonates are generally well tolerated and associated with minimal adverse effects; however, there exists a growing concern that bisphosphonate use may be associated with osteonecrosis of the jaw.

CASE PRESENTATION: We report the occurrence of osteonecrosis of the jaw associated with pamidronate therapy in 4 patients undergoing treatment for multiple myeloma. At the onset of jaw osteonecrosis, pamidronate therapy was the single medication common to all 4 patients. The duration of therapy varied from 18 to 65 months before osteonecrosis was observed. All cases involved the posterior mandible and have been refractory to a variety of medical therapies including surgical debridement and systemic antibiotics. Biopsies available from two patients revealed inflammation consistent with osteomyelitis. In one biopsy Actinomyces spp. were recovered from culture, but treatment with an extended course of clindamycin conferred no clinical benefit. The persistence of exposed bone remains a significant source of morbidity and pain for each patient. Discontinuation of pamidronate therapy has not helped to reverse the presence of osteonecrosis and surgical manipulation of the involved site appears to worsen the underlying bone pathology.

CONCLUSIONS: Osteonecrosis of the jaw is an important adverse outcome associated with bisphosphonate therapy. The unremitting nature of this clinical development, and the long lasting morbidity associated with it suggests that patients should be counseled regarding the possible occurrence of osteonecrosis prior to initiating therapy with pamidronate.