[Jaw osteonecrosis induced by oral biphosphonates: 12 cases]

The incidence of jaw osteonecrosis induced by oral or intravenous biphosphonates (BP) has been increasing. Two hundred cases of jaw osteonecrosis induced by oral BP (JONOBP) were reported, with an incidence of 4 % and a prevalence of 1/952. We report 12 cases of JONOBP observed from January 2007 to January 2009.A pluridisciplinary committee including odontologists, stomatologists, and maxillofacial surgeons from two Paris hospitals was asked to manage patients treated by BP. Twelve patients presenting with JONOBP were included from January 2007 to January 2009. For each of these patients, age, sex, associated co-morbidities, any triggering factor, previous or current combination treatments, the type of BP used, its initial indication, dosage, delay before onset of JONOBP, and delay between first clinical signs and diagnosis were studied. JONOBP localization, stage (American Association of Oral and Maxillofacial Surgeons [AAOMS] classification), clinical and radiological signs, anatomopathological and bacteriological examinations (when performed) were documented. The treatment and evolution were described.Ten women and two men, mean age 65 years (36 to 82 years), were included. BP were taken orally once a week or daily. The mean duration of BP exposure was 39.6±2,4 months (19 to 58 months). The indication for BP was prevention or treatment of osteoporosis in 11 cases and breast with bone metastases in one case. Tooth extraction was the triggering factor in nine cases. The premolar and molar mandibular area was the most often affected. Corticosteroid therapy was combined to BP in half of the cases. There were no clinical, radiological, and histological specific signs. BP treatment was stopped in all patients. Nine patients underwent surgery. Evolution was favorable for nine patients. Six patients were cured, on average 3.8 months after beginning management (one to nine months). Three male patients improved. Three female patients were lost to follow-up. Alendronate was the most frequently implicated (six cases) and risedronate (five cases). Five patients presented with diagnosed or suspected auto-immune conditions.The duration of exposure to BP was superior to three years in most cases. The triggering factor was tooth extraction. The mean diagnostic delay was five months. There were more stage 2 and 3 patients, according to the AAOMS classification. They were the most frequent, probably because of the higher number of co-morbidities, especially corticosteroid intake. Patient management complied to Afssaps and AAOMS recommendations. The evolution was favorable for all managed patients.