FIG 5. A, Comparison between direct osteometry and dental MR imaging. Measurements obtained by direct osteometry are drawn on the x-axis and corresponding measurements obtained on dental MR images are drawn on the y-axis (diamonds). With a 100% correlation between dental MR and direct osteometry, all dental MR measurements would meet the first median (straight line). Overestimations of distances judged on dental MR images thus lie above and underestimations below the first median. Excellent linear correlation between dental MR imaging and direct osteometry, with nearly all measurements fitting the first median, is shown.

B, The correlation between direct osteometry and dental MR imaging was only moderate in regard to the diameter of the bone cortex at the edge of the alveolar ridge (DBC).

C, Dental CT also shows a strong linear correlation with direct osteometry. The dental CT measurements (squares) nearly meet the first median (straight line).

D, For dental CT measurements, the diameter of the bone cortex at the edge of the alveolar ridge (DBC) was only moderately linearly correlated with that of direct osteometry.

E, Dental CT and MR imaging show the strongest linear correlation. Dental MR measurements are drawn on the y-axis (triangles) and dental CT measurements on the x-axis. Dental MR shows a very slight overestimation of distances (shown as points lying above the expected first median) compared with dental CT measurements.

F, Because on dental CT and MR images the transition between cortical and spongy bone appears to be sharp, correlation was extremely strong for the measurements of the diameter of cortical bone at the edge of the alveolar ridge (DBC), although the correlation of both techniques with direct osteometry was only moderate. Measurements from dental MR images are drawn on the y-axis (dots) and those of dental CT scans on the x-axis. With a 100% correlation, all measurements would lie on the first median (straight line).