Occurrence of Bisphosphonate-Related Osteonecrosis of the Jaw After Surgical Tooth Extraction

Purpose: To evaluate the occurrence of bisphosphonate-related osteonecrosis of the jaw (BRONJ) in patients exposed to nitrogen-containing bisphosphonates (NBPs) requiring surgical tooth extraction. Patients and Methods: Sixty high-risk patients exposed to NBPs underwent surgical tooth extraction with bone biopsy and were treated with a 7-day cycle of oral antibiotics and discontinuation of NBPs for 1 month. BRONJ was defined as the occurrence of any BRONJ stage (0-3) at 3, 6, or 12 months of follow-up. Inferential analysis was performed on a per-bone (maxilla and/or mandible) basis (n=72). The time to BRONJ was calculated, and age, gender, cancer diagnosis, and baseline osteomyelitis were evaluated as potential predictors. Exact logistic regression was used to model the time-to-outcome relationship, and hazard rates were calculated from logistic probabilities. Results: BRONJ was detected at 3 months' follow-up in 4 bones and at 6 months in 1 further bone. In the whole cohort of bones, the hazard rate of BROM was 5.6% at 3 months and 1.5% at 6 months. Baseline osteomyelitis was a strong risk factor for BROM development (odds ratio, 156.96; exact 95% confidence interval, 18.99 to (infinity); exact P<.0001). Conclusion: In this 12-month follow-up study, BRONJ was a rare outcome in high-risk NBP users who underwent surgical tooth extraction. Moreover, baseline osteomyelitis was a very strong risk factor for BRONJ development. (C) 2010 American Association of Oral and Maxillofacial Surgeons J Oral Maxillofac Surg 68:797-804, 2010