Zahra Dalili Kajan - Oral and Maxillofacial Radiology Department, Dental School, Guilan University of Medical Sciences, Rasht, IR Iran
Navid Karimi Nasab - Orthodontics Department, Dental School, Guilan University of Medical Sciences, Rasht, IR Iran
Jalil Khademi - Orthodontics Department, Dental School, Guilan University of Medical Sciences, Rasht, IR Iran
Faegheh Gholinia - Orthodontics Department, Dental School, Guilan University of Medical Sciences, Rasht, IR Iran
Zeinab Taheri - Dentist, Dental School, Guilan University of Medical Sciences, Rasht, IR Iran
Mona Hajighadimi - ۴Dentist, Private Clinic, Rasht, IR Iran

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 ۱۱ orthodontic patients were selected. Three fourth-year dental students were asked to identify ۱۹ NLs after calibrating digital lateral cephalograms and ۳D 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 -۱.۰۳ to ۲.۷۴ in two-dimensional cephalometry and a range of -۰.۸۸ to ۲.۳۱ in ۳D CBCT, showing a ۹۵% limit of agreement. According to the intraclass correlation coefficient (ICC) comparison made by our student observers, only ۵% of interobserver assessment in CBCT and ۲۰% 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 = ۰.۰۰۰۱). Conclusions The training of cephalometric tracing in orthodontic course based on ۳D 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.

Anatomic Landmark, Cephalometry, Cone Beam Computed Tomography