Correlation between MCI/Sapori screening tools and DXA results and between MCI/Sapori and Frax tool for estimating fracture risk

Background: Peripheral Dual-energy X-ray absorptiometry (DXA) can be applied to identify low bone mineral density (BMD) patients, however, DXA is not sufficiently available in many countries. Thus, the use of simpler and cheaper screening tools than DXA to detect low BMD become indispensable. Objectives: The objective of this study was to correlate São Paulo osteoporosis risk index (Sapori) and mandibular cortical index (MCI) screening tools with the femur DXA results of patients in our sample of Brazilian women. A secondary objective was to assess which of these screening tools better correlates with the results of the Frax tool. Material and Methods: Exams of women who had undergone panoramic radiographic examination at the beginning of dental treatment and peripheral DXA for screening osteoporosis from 2010 to 2014 were included. The MCI was evaluated, and Sapori and Frax were calculated with their available online software tools. Spearman correlation was performed to analyse the level of correlation between femur T-scores (and MCI and Sapori values, as well to perform the level of correlation between Frax and MCI and Sapori values. Results: The spearman correlation comparing the numerical T-score values and the categorical values of MCI (rs=-0.274), and of Sapori (rs=-0.470), showed a statistically significant inverse correlation for both equations (p<0.01). The Spearman equation comparing the values obtained with Frax and MCI did not show a statistically signifcant correlation (p>0.01). But the equation comparing the values obtained with Frax and Sapori showed a positive, moderate and statistically significant correlation between them (rs=0.460). Conclusion: MCI is not a reliable screening tool to identify women with low BMD or Osteoporosis, whereas more optimistic results were observed for the Sapori.