A comparison of two-dimensional radiography and three-dimensional computed tomography in angular cephalometric measurements

Abstract

Objectives: The objective of this study was to assess the reliability of three-dimensional (3D) cephalometric approaches by comparing this method with authenticated traditional twodimensional (2D) cephalometry in angular cephalometric measurements. Methods: CT images and lateral cephalometric radiographs of ten patients (five women, five men) were used in this study. Raw CT data of the patients were converted to 3D images with a 3D simulation program (Mimics 9.0, Leuven, Belgium). Lateral cephalometric radiographs were used manually for 2D measurements. The comparisons of the two methods were made using 14 cephalometric angular measurements. The Wilcoxon matched-pairs signed-ranks test (a 5 0.05) was used to determine the difference between the two methods. To assess the intra-and interobserver reproducibility, two sets of recordings made by each observer, in each modality were used. Dahlberg's formula was used to determine the intraobserver reproducibility, and the Wilcoxon matched-pairs signed-rank test (a 5 0.05) was used to assess the interobserver reproducibility. Results: The method errors of both observers ranged from 0.35˚to 0.65˚. In addition, there were no significant differences between the measurements of the two observers (P . 0.05). However, comparison of 2D and 3D parameters showed significant differences in U1-NA and U1-SN measurements (P , 0.05). Conclusions: The 3D angular cephalometric analysis is a fairly reliable method, like the traditional 2D cephalometric analysis. Currently, the 3D system is likely to be more suitable for the diagnosis of cases with complex orthodontic anomalies. However, with the decrease in radiation exposure and costs in the future, 3D cephalometrics can be a suitable alternative method to 2D cephalometry.

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

“…As our results, they did not find statistically significant differences for either the Na-Me or Ans-Me distances, concluding that it is possible to use most of the values previously established in 2D for measuring 3D records, as the differences between both systems were small. Other authors have also compared angular measurements between LCR and CT. 30 They found only statistically significant differences in 2 of the 14 measurement that they carried out, upper incisor-Na and upper incisor-NS. However, in our study, we did not find such difference for the upper incisor-NS angle.…”

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

“…[5,10,27,31À33] However, few studies have used CBCT-generated cephalograms using rendering programs in vivo. [5,6,14,27,34] The current study evaluated the reliability of linear and angular measurements in four rendering software programs; either in 2D or 3D generated cephalograms. According to the results, most of the cephalometric parameters used in this study showed no statistical differences between the measurements obtained by 2D Vista Dent tracing method and those obtained from CBCT-generated cephalograms (p > 0.05).…”

“…Nalcaci et al [6] evaluated 3D cephalometric images and traditional 2D images in terms of angular measurements. They also used a third-party software program (Mimics 9.0, Leuven, Belgium).…”

“…[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.…”

Validity and reproducibility of cephalometric measurements performed in full and hemifacial reconstructions derived from cone beam computed tomography

“…Lateral cephalometric radiography (LCR) has been used since 1931 1 as a standard tool for craniofacial morphology analysis, orthodontic diagnosis, and treatment. [2][3][4] Using LCR, longitudinal studies of craniofacial growth and development were performed for analysis of dentoskeletal relationships in individuals with normal facial pattern. From these studies, standard measures of craniofacial relationships were obtained.…”