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 BRONJ was 5.6% at 3 months and 1.5% at 6 months. Baseline osteomyelitis was a strong risk factor for BRONJ development (odds ratio, 156.96; exact 95% confidence interval, 18.99 to ; 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.