Validating 2D radiographic markers using ConeBeam CT to diagnose osteoporosis

Objective: To evaluate the utility of previously established 2-D radiographic indices using CBCT images and assess the correlation with dual energy x-ray absorptiometry (DXA) values to develop a CBCT based radiomorphometric model for diagnosing osteoporosis.

Method: Data from 29 patients who were participants in a best-practice study of postmenopausal women receiving dental implant placement with ridge augmentation were analyzed.  Patients had received a CBCT and DXA scans pre-operatively. The Mental Index (MI) was chosen for its reliability based on previously published studies. Thickness of the inferior cortical border of mandible at a standardized region inferior to the mental foramen was measured. Correlation of these values with DXA values of the femoral neck, total hip and spine on normal, osteopenic and osteoporotic postmenopausal women was assessed. 

Result: There was no correlation between the spine and hip T-Scores with thickness of the mandible on the right side(r=0.081,p=0.676,r=0.030,p=0.876),the left side(r=0.053,p=0.786,r=0.020,p=0.919) or the average of the sides( r=0.020, p=.919 r=0.028,p=0.887).There was a correlation between the thickness of the inferior cortical border of the mandible on the right and left sides(r=0.678 and p=.000). There was also a strong correlation between age and thickness on the right side (r=0.458 and p=.012).

 Conclusion: In contrast to previous studies utilizing 2-D images, this study using 3-D images did not show any correlation between the MI and DXA scan values. However, the data does show a strong correlation between age and thickness of the inferior cortical border.