Periodontal Disease as a Risk Factor for Bisphosphonate-Related Osteonecrosis of the Jaw

Background: Previous case reports and animal studies suggest that periodontitis is associated with bisphosphonate-related osteonecrosis of the jaw (BRONJ). This case-control study is conducted to evaluate the association between clinical and radiographic measures of periodontal disease and BRONJ. Methods: Twenty-five patients with BRONJ were matched with 48 controls. Trained examiners measured probing depth, clinical attachment level (CAL), and bleeding on probing on all teeth except third molars and gingival and plaque indices on six index teeth. Alveolar bone height was measured from orthopantomograms. Most patients with BRONJ were using antibiotics (48%) or a chlorhexidine mouthrinse (84%) at enrollment. Adjusted comparisons of patients with BRONJ versus controls used multiple linear regression. Results: The average number of bisphosphonate (BP) infusions was significantly higher in patients with BRONJ compared with controls (38.4 versus 18.8, P = 0.0001). In unadjusted analyses, patients with BRONJ had more missing teeth (7.8 versus 3.1, P = 0.002) and higher average CAL (2.18 versus 1.56 mm, P = 0.047) and percentage of sites with CAL >= 3 mm (39.0 versus 23.3, P = 0.039) than controls. Also, patients with BRONJ had lower average bone height (as a fraction of tooth length, 0.59 versus 0.62, P = 0.004) and more teeth with bone height less than half of tooth length (20% versus 6%, P = 0.001). These differences remained significant after adjusting for age, sex, smoking, and number of BP infusions. Conclusions: BRONJ patients have fewer teeth, greater CAL, and less alveolar bone support compared with controls after adjusting for number of BP infusions. Group differences in antibiotics and chlorhexidine rinse usage may have masked differences in the other clinical measures.