Periodontal Disease and Bisphosphonate-Related Osteonecrosis of the Jaw

Objectives: Previous reports suggest that poor oral hygiene predisposes patients to developing Bisphosphonate-Related Osteonecrosis of the Jaw (BRONJ). We did a case-control study to evaluate the association between clinical measures of periodontal disease and BRONJ. 

Methods: 22 cancer patients (15 female, mean age=64yrs) who developed BRONJ after intravenous bisphosphonate (BP) treatment were matched with 22 controls (17 female, mean age=62 yrs) who did not develop BRONJ. All subjects had received at least 10 intravenous BP infusions, most for metastatic breast cancer management (12 BRONJ, 17 controls).  For each subject, one of two calibrated examiners measured probing depth (PD), clinical attachment loss (CAL), and bleeding on probing (BOP) at six sites on all teeth except third molars, and measured gingival index (GI) and plaque index (PI) on six index teeth. As part of BRONJ management, most cases were using antibiotics (50%) or chlorhexidine mouth rinse (82%) at the time of enrolment.

Results: BRONJ subjects had more missing teeth than controls (mean 10.1 vs 4.6; p=0.03). In unadjusted analysis, BRONJ subjects and controls did not differ significantly in average PD (2.03 vs 1.99 mm, p=0.70), average CAL (2.19 vs 1.59 mm, p=0.17), percent of sites with BOP (12% vs 12%, p=0.88), average GI (0.55 vs 0.60, p=0.50), average PI (0.40 vs 0.54, p=0.21), or percent of sites with probing depth ≥4 mm (4.8% vs 3.2%, p=0.29) or ≥5 mm (1.8% vs 0.6%, p=0.08). After adjusting for age, sex and smoking, cases and controls did not differ significantly for any measure including tooth loss (p=0.09).

Conclusions: Preliminary analyses from the present study indicate that measures of periodontitis and oral hygiene are not associated with risk of developing BRONJ after intravenous BP therapy.  Imbalances in antibiotics and chlorhexidine mouth rinse usage between the groups may have eliminated or reduced differences in GI or PI.