Cephalometric measurements from 3D reconstructed images compared with conventional 2D images

Abstract

Objective: To assess whether the values of different measurements taken on three-dimensional (3D) reconstructions from cone-beam computed tomography (CBCT) are comparable with those taken on two-dimensional (2D) images from conventional lateral cephalometric radiographs (LCRs) and to examine if there are differences between the different types of CBCT software when taking those measurements. Material and Methods: Eight patients were selected who had both an LRC and a CBCT. The 3D reconstructions of each patient in the CBCT were evaluated using two different software packages, NemoCeph 3D and InVivo5. An observer took 10 angular and 3 linear measurements on each of the three types of record on two different occasions. Results: Intraobserver reliability was high except for the mandibular plane and facial cone (from the LCR), the Na-Ans distance (using NemoCeph 3D), and facial cone and the Ans-Me distance (using InVivo5). No statistically significant differences were found for the angular and linear measurements between the LCRs and the CBCTs for any measurement, and the correlation levels were high for all measurements. Conclusion: No statistically significant differences were found between the angular and linear measurements taken with the LCR and those taken with the CBCT. Neither were there any statistically significant differences between the angular or linear measurements using the two CBCT software packages. (Angle Orthod. 2011;81:856-864.)

Effects of fixed functional therapy on tongue and hyoid positions and posterior airway

“…26,27 A high correlation between posterior airway size on cephalometric radiographs and pharyngeal volume measured on tomographic scans has been reported. 28 Furthermore, Miles et al 29 reported a high reliability of identification of the commonly used cephalometric landmarks and measurements.…”

Comparison of linear and angular measurements in CBCT scans using 2D and 3D rendering software

“…Another study by Zamora et al [3] evaluated whether the angular and linear measurements of 3D reconstructions obtained from CBCT are equal to those of 2D images obtained from the cephalograms using two different software packages (Beta Nemoceph 3D, Software Nemotec, SL, Madrid, Spain, and In vivo 5 Anatomage, San Jose, CA). In this study, no statistically significant differences were found for 2D and 3D generated cephalograms.…”

“…[3,4,6,7] Additionally, one of the most common insufficiencies of 2D methods with lateral cephalometric radiography and cephalometric analysis is double imaging of the lower borders of the mandible. Therefore, observer identification errors are also common in orthodontic anatomical landmarks.…”

Cone beam computed tomography use in orthodontics

“…Only three studies did not validate CBCT image superiority over 2-D lateral cephalograph. 10,13,14 Even in a rigorous test against the gold standard of caliper measurements on dry skulls, CBCT measurements were deemed clinically accurate, although the mean percent measurement error for CBCT images was 2.31% compared to 0.63% for calipers. 15 CBCT overcomes the sources of error in conventional 2-D radiographs: relatively low resolution, magnification error, image distortion and superimposition of structures.…”