Editor's Summary and Q&A: Accuracy and reliability of linear cephalometric measurements from cone-beam computed tomography scans of a dry human skull

Abstract

<h3>Introduction</h3> The purpose of this study was to determine the accuracy and reliability of 3-dimensional craniofacial measurements obtained from cone-beam computed tomography (CBCT) scans of a dry human skull. <h3>Methods</h3> Seventeen landmarks were identified on the skull. CBCT scans were then obtained, with 2 skull orientations during scanning. Twenty-nine interlandmark linear measurements were made directly on the skull and compared with the same measurements made on the CBCT scans. All measurements were made by 2 operators on 4 separate occasions. <h3>Results</h3> The method errors were 0.19, 0.21, and 0.19 mm in the x-, y- and z-axes, respectively. Repeated measures analysis of variance (ANOVA) showed no significant intraoperator or interoperator differences. The mean measurement error was –0.01 mm (SD, 0.129 mm). Five measurement errors were found to be statistically significantly different; however, all measurement errors were below the known voxel size and clinically insignificant. No differences were found in the measurements from the 2 CBCT scan orientations of the skull. <h3>Conclusions</h3> CBCT allows for clinically accurate and reliable 3-dimensional linear measurements of the craniofacial complex. Moreover, skull orientation during CBCT scanning does not affect the accuracy or the reliability of these measurements.