Two-dimensional and three-dimensional cephalometry using cone beam computed tomography scans

Lateral cephalometric radiograph produces a two-dimensional image with several drawbacks. Cone beam computed tomography (CBCT) allows obtaining a three-dimensional representation of the craniofacial structures and seems to overcome the problems of superimposition and magnification, providing more precision than two-dimensional methods. The aim of the current study was to test the intraobserver and interobserver reliability of linear and angular measurements performed on two-dimensional conventional cephalometric images and CBCT-generated cephalograms, and to evaluate if there is a statistically significant difference between the 2 methods of measurements. The sample group consisted of 24 adolescents with a pretreatment digital lateral radiograph and a corresponding CBCT image. A total of 16 cephalometric landmarks were identified and 17 widely used measurements (9 angular and 8 linear) were recorded by 2 independent observers. Intraobserver and interobserver reliability were assessed by calculating Pearson correlation coefficient. Student t-test was used to compare the 2 methods. The threshold for significance was set at P ≤ 0.05.Concerning the intraobserver and interobserver reliability, data showed a statistically significant correlation between all two-dimensional and three-dimensional measurements. The linear and angular measurements of two-dimensional and three-dimensional cephalometry were not statistically different. The results of the current study showed the reliability of both conventional two-dimensional and three-dimensional cephalometry. Linear and angular measurements from CBCT were found also to be similar to conventional measurements. Considering that conventional images deliver the lowest radiation doses to patients, the use of CBCT for orthodontic purposes should be limited.