Opportunistic screening for osteoporosis using dental radiographic indices

Early identification of individuals at risk for osteoporosis is essential for timely intervention and prevention of fragility fractures. This study aimed to assess the diagnostic value of dental radiographic indices obtained from panoramic radiography and cone beam computed tomography (CBCT) for the early detection of osteoporosis, using dual-energy X-ray absorptiometry (DXA) as the reference standard.

Seventy (n = 70) postmenopausal women underwent panoramic radiography, CBCT, and DXA examinations. Images were evaluated by an oral surgeon certified in oral radiology. The Mandibular Cortical Index (MCI), Mental Index (MI), Panoramic Mandibular Index (PMI), and Molar Index (M index) were evaluated using panoramic images. Corresponding computed tomography (CT)-based indices, specifically the Computed Tomography Mandibular Cortical Index (CTMCI), Computed Tomography Mental Index (CTMI), Computed Tomography Panoramic Mandibular Index (CTPMI), and Computed Tomography Molar Index (CTM index), were derived from CBCT measurements.

PMI, CTPMI, and the M index demonstrated the highest diagnostic performance for osteoporosis detection. Specifically, the highest areas under the curve (AUC) for distinguishing normal individuals from those with osteoporosis were observed for PMI (AUC = 0.89, 95% CI: 0.77-1.00), CTPMI (AUC = 0.88, 95% CI: 0.75-1.00), and the M index (AUC = 0.86, 95% CI: 0.73-0.99). Optimal cutoff values were approximately 3.5-4.0 for MI and CTMI, 0.32-0.38 for PMI and CTPMI, and 3.1-3.35 for the M index. Diagnostic accuracy was higher for differentiating normal individuals from osteoporotic individuals than from osteopenic individuals.

Dental radiographic indices derived from panoramic radiography and CBCT may represent useful opportunistic screening tools for identification of postmenopausal women at risk for osteoporosis. The proposed cutoff values could assist clinicians in recognizing individuals who may benefit from referral for DXA assessment and further evaluation of bone mineral density.