[Osteonecrosis of the jaws associated with bisphosphonates: five cases]

Bisphosphonates have been recently associated with bone necrosis of jaws.

Five patients were treated, two males and three females. All patients received bisphophonates and chemotherapeutic agents, two for multiple myeloma and three for breast cancer with bone metastasis. Bisphophonates were discontinued. None of the patients had received radiotherapy to the head and neck. The localization was mandibular in four patients and the maxillary area in one with oro-antral fistula. Histological and microbiological studies were performed.

Histopathology demonstrated osteonecrosis and ruled out detectable neoplastic disease of the jaws. Four biopsies showed Actinomycosis. Four patients underwent sequestrectomy, but the mucosa did not heal.

Two mechanisms are involved: the antiangiogenic effect of bisphophonates has recently been described in vivo; as bone mineralization increases, accumulation of microdamage is observed in animals studies. Only the jaws are affected by bone necrosis, suggesting a possible trophism for bisphosphonate uptake? Other risks factors have been found: cancer, use of chemotherapeutic agents or corticosteroids, renal failure, Actinomycosis infection. The only effective treatment is dental prevention before starting treatment.