Have panoramic indices the power to identify women with low BMD at the axial skeleton?

The purpose of this study was to investigate whether panoramic mandibular indices i.e. mandibular cortical width (MCW), alveolar bone resorption degree (M/M ratio) and panoramic mandibular index (PMI) can be used as pre-selection tests to identify women with low bone mineral density (BMD) at the axial skeleton. MCW, PMI and M/M ratio were measured on dental panoramic radiographs in a group of 151 postmenopausal women aged 38-80 years. BMD at the lumbar spine and hip was measured by dual energy X-ray absorptiometry. BMD values were categorized as normal, osteopenic or osteoporotic according to the WHO classification. ROC analysis was used to determine cut-off values for MCW. MCW performed better than PMI and M/M ratio in its power to differentiate women with osteopenia or osteoporosis from healthy subjects. Cut-off values for the MCW estimated to detect women with T-score < -1 and those with T-score ≤ -2.5 identified a total of 45% and 34% of subjects respectively. Sensitivity and specificity was found to be low ranging between 55 and 70 for both cut-off values. Panoramic indices appear to have limited power in their ability to identify women with low BMD at the axial skeleton.