Comparison of landmark reliability from lateral cephalograms and 3d images

Objective: The purpose of this study was to determine and compare the intra- and inter-examiner reliability of commonly used cephalometric landmarks obtained from digitized lateral cephalograms with formatted CBCT images from 10 adolescent patients randomly selected from existing orthodontic records. Methods: Measurement errors and intra, inter-examiner reliability correlation coefficients (ICC) were obtained for all landmarks coordinates. Results: Intra- and inter-reliability for all coordinates for most of the landmarks in digital lateral cephalograms and CBCT were greater than 0.9 (ICC value). Mean difference obtained from trials within the same examiner and when comparing the three examiners were less than 0.5 mm for all landmark coordinates. Location of landmarks differed in less than 0.5 mm in all coordinates in lateral cephalograms and in 90% of the coordinates in CBCT images. Conclusions: Coordinates that presented a higher measurement error in the CBCT images (Gonion and Porion) were located on surfaces which were flat or curved making it difficult to recognize a reference point for each.