Mandibular BV/TV Ratios in Women with Breast Cancer and ONJ

Osteonecrosis of the jaw is a debilitating oral condition associated with the use of intravenous amino-bisphosphonates. The ability to diagnose a preclinical lesion, as well as identify risk factors, is important for the management of the disease. Quantification of bone properties may shed light on the progression of the disease. Objective: The purpose of this study was to use MicroCT in conjunction with images obtained from a CBCT machine to quantify the BV/TV (Bone Volume / Total Volume) ratios in the mandibles of women with clinically diagnosed bisphosphonate-related osteonecrosis of the jaw and to compare that data with a control group. Method: The volumetric data obtained via CBCT scans was exported using iCATVision software to be analyzed with MicroCT software. The contouring tool of the MicroCT software was used to perform analyses on cortical and trabecular bone in the mandibles of the control group and subject group. Evaluation scripts designed for cortical and trabecular bone, respectively, were used. Comparisons between the subject and the control, and between the left and right sides in the subset of subjects group were analyzed with GraphPad Prism software using two-tailed unpaired and paired t-tests (p<0.05). Results: Within a region near the lesion, a significant increase in the volume of trabecular bone per total volume was measured in the breast cancer subjects. A significant difference in trabecular BV/TV between the lesion side and the non-lesion side also existed. No significant differences between the cortical and trabecular BV/TV ratios for the whole mandible, nor for the cortical ratios near the lesion site, were measured. Conclusions: The results suggest that quantifiable changes in bone properties in subjects with osteonecrosis of the jaw may be localized to regions near the lesion. MicroCT and CBCT imaging can be used to quantify BV/TV changes.