The CBCT devices evaluated in this study are suitable for taking exact 3D measurements of anatomical structures and meet all requirements for 3D cephalometric analysis.

The aim of this study was to analyze the imaging accuracy of cone beam computed tomography (CBCT) data sets compared with multislice spiral computed tomography (MSCT) data sets in determining the exact mesiodistal width of unerupted porcine tooth germs and to compare the radiologically obtained results of width measurements with the actual mesiodistal dimension of the tooth germs. In MSCT and CBCT data sets, the largest diameter of 24 tooth germs was determined with the aid of the mesial and distal contact points. The reference method used was mesiodistal width measurement using sliding callipers after the tooth germs had been osteotomized. Accuracy and precision were ascertained with difference plots and a one-way model II analysis of variance with random effects. Analysis of accuracy revealed marked differences between the measuring methods in the difference plot: slightly higher mean values were measured by MSCT and markedly lower values by CBCT than by the reference method (calliper); the mean deviation was significantly greater for CBCT. The width of the confidence interval in the comparison of CBCT versus clinical measurements is more than 4 times higher than in the comparison of MSCT versus clinical values. Precision analysis found that repeatability was twice as high with CBCT as with clinical measurement, whereas MSCT and clinical measurement differed only slightly. The mesiodistal width of displaced teeth can be determined by MSCT but also by CBCT. MSCT is superior to CBCT in determining tooth width; the difference was statistically significant (P = 0.05).

All selected landmarks offer suitably high levels of intra- and interserial precision for the three-dimensional (3D) metric assessment of facial soft-tissue parameters. No difference between (bi)lateral and facial midline landmarks was noted.

The volumetric data from an MSCT system gives highly accurate information on the mesiodistal width of displaced canines.