Background: Proper defining of normal landmarks in lateral cephalograms is important for establishing proper orthodontic treatment plan.
Objectives: To evaluate the agreement of dental students to identify normal landmarks (NLs) in digital lateral cephalograms and cone beam computed tomography (CBCT) images.
Patients and Methods: In this study, lateral cephalograms and CBCT images of 11 orthodontic patients were selected. Three fourth-year dental students were asked to identify 19 NLs after calibrating digital lateral cephalograms and 3D CBCT images. Then, the distances of each landmark from the superior and anterior edges of the images were measured for each observer.
Results: The observers’ errors fell within a range of -1.03 to 2.74 in two-dimensional cephalometry and a range of -0.88 to 2.31 in 3D CBCT, showing a 95% limit of agreement. According to the intraclass correlation coefficient (ICC) comparison made by our student observers, only 5% of interobserver assessment in CBCT and 20% in lateral cephalometry showed poor reliability. These same observers showed more agreement when identifying NLs on soft tissue as compared to hard tissue structures and also in detecting NLs located in the midsagittal region rather than on lateral sides in both modalities. Their differences in agreement in detecting midsagittal NLs rather than on lateral sides were statistically significant (P = 0.0001).
Conclusions: The training of cephalometric tracing in orthodontic course based on 3D skull models and imaginary methods was deemed successful in increasing the ability of dental students to determine the precise location of NLs, even on CBCT images.