Oral Health Risk Factors for Bisphosphonate-associated Jaw Osteonecrosis

Osteonecrosis of the jaw has been associated with bisphosphonates, though the pathophysiology is poorly understood. Periodontal disease occurs in up to 80% of bisphosphonate-associated jaw osteonecrosis (ONJ) cases, suggesting it is a risk factor. However the role of oral health, including periodontal disease, as a risk factor for ONJ has not been investigated comprehensively. Objectives: The study used a cross-sectional study design to investigate if ONJ was associated with poor oral health. Methods: Cases with ONJ (n= 22) and controls with no ONJ (n=41) were recruited from specialist dental clinics and oncology clinics. All had a history of exposure to intravenous (IV) bisphosphonates for malignancy. Participants underwent a medical questionnaire and a clinical oral examination according to the National Survey of Adult Oral Health protocol. This protocol was modified to include assessment of probing depth (PD) and clinical attachment loss at six sites for each tooth. Results: No significant differences were found between the groups in age, sex and medical history, except cases had a significantly longer time since last bisphosphonate infusion (p=0.010) and more had ceased IV bisphosphonate therapy (p=0.000). No significant differences were found between the groups in terms of the number of teeth missing, untreated caries and the DMF (decayed, missing, filled) indices at both the tooth and surface levels. Periodontal disease levels were significantly higher in the ONJ group (p=0.003) according to the United States National Center for Health Statistics classification of periodontal disease, and cases also had significantly more sites with PD at least 4mm (p=0.007). Other periodontal disease measures were comparable. Conclusions: In participants with a history of IV bisphosphonates, levels of periodontal disease were higher in the group with ONJ compared to those without, but not in all measures. Further longitudinal research is required to clarify the association. Funding: ADRF (10/2008), APRF (2009).