Associations between Systemic Markers of Bone Turnover or Bone Mineral Density and Anti-Resorptive Agent-Related Osteonecrosis of the Jaw in Patients Treated with Anti-Resorptive Agents

BACKGROUND Some previous studies have examined anti-resorptive agent-related osteonecrosis of the jaw (ARONJ) prediction using systemic markers of bone turnover as risk factors. Radiographic imaging is also effective at detecting ARONJ. In this study, computed tomography (CT)-derived bone mineral density (BMD) values and the levels of systemic markers of bone turnover were evaluated, and then each parameter was compared between patients that developed ARONJ and those who did not after treatment with systemic anti-resorptive agents. The aim of this study was to determine whether systemic markers of bone turnover and/or BMD values can be used to predict the risk of ARONJ. METHODS The subjects' serum levels of cross-linked N-terminal telopeptide of type I collagen (NTX) and bone alkaline phosphatase (BAP) (systemic markers of bone turnover) were measured. BMD was calibrated to CT values using a medical imaging phantom. Then, the subjects' BMD were assessed using quantitative computed tomography. Fifty-six patients who had received systemic anti-resorptive agents were included in this study. Thirty-two of the patients developed ARONJ after receiving the drugs whereas the remaining 24 did not. RESULTS No correlation was observed between the serum levels of the systemic markers of bone turnover and the incidence of ARONJ. On the other hand, the ARONJ patients exhibited higher mandibular BMD values than the control group. BMD was not associated with healing or the clinical stage of ARONJ. CONCLUSION These results suggest that increased mandibular BMD values are associated with ARONJ. Furthermore, mandibular BMD might serve as a novel marker for predicting the risk of ARONJ in patients that are taking anti-resorptive agents and are about to undergo tooth extraction. Accordingly, mandibular BMD could be a useful tool for aiding risk assessments and guiding treatment decisions.