New mandibular indices in cone beam computed tomography to identify low bone mineral density in postmenopausal women.

OBJECTIVE

The aim of this study was to evaluate new radiomorphometric indices in cone beam computed tomography (CBCT) for assessing bone mineral density (BMD) status in postmenopausal women.

STUDY

DESIGN

Mandibular inferior cortical bone thickness was evaluated in 48 postmenopausal women in cross-sectional images at 4 sites: (1) symphysis (S): cross-sectional image equidistant from the centers of the right and left mental foramina (MF); (2) anterior (A): 10 mm anterior to the MF; (3) molar (M): 10 mm posterior to the MF; and (4) posterior (P): 25 mm posterior to the MF. Participants underwent dual-energy x-ray absorptiometry and were divided into normal, osteopenia, and osteoporosis groups. In the study, t tests with Bonferroni correction were conducted. Statistical significance was set at P < .017. Receiver operator characteristic (ROC) analyses were performed.

RESULTS

Mean S index was significantly lower in osteoporosis than in osteopenia (P = .005). Mean M index was significantly lower in osteopenia (P < .001) and osteoporosis (P = .001) than in normal individuals. Mean P index was significantly lower in osteoporosis than in normal patients (P = .008). ROC values ranged between 0.643 and 0.740. Cortical thicknesses separating normal from abnormal varied from 1.73 mm to 3.37 mm.

CONCLUSIONS

M and P indices in CBCT may be useful for identifying low BMD in postmenopausal women.