Evaluation of Ricketts Frontal Analysis Reference Points on Cone-beam Computed Tomography Images

Aims: The aim of this study was to evaluate the reliability of Ricketts frontal analysis reference points when viewed by three-dimensional images.

Methodology: The points related to the Ricketts frontal analysis were identified at multiplanar reconstructions (MPR) and three-dimensional reconstructions (Rec 3D) obtained from cone-beam computed tomography. The cephalometric landmarks, following the author’s definition, were located by three operators: an orthodontist, a radiologist, and a student coursing the eighth period of the graduation course in dentistry. After two weeks, the landmarks were repeated. The values of X, Y, and Z were obtained for each point, and the intraclass correlation coefficient was calculated.

Results: The intraclass correlation coefficient values were less than 0.45 (poor reliability) at 15 points viewed from the three-dimensional reconstructions and 8 points for the multiplanar reconstructions, including the intra and interobserver assessments. It was not possible to identify the J point on the CBCT images.

Conclusion: The multiplanar reconstructions allow greater reliability in the identification of the anatomical landmarks for both intra and interobserver assessments. To improve its reliability, Ricketts frontal analysis reference points must be defined in the three planes of space before transfer to three-dimensional images, or new anatomical references can be adopted.