Comparison between two-dimensional and three-dimensional imaging utilizing the Grummons frontal analysis

Objectives: The purpose of this study is to compare the parameters of the Grummons analysis applied to the cone beam computer tomography (CBCT) constructed posteroanterior (PA) cephalograms and multiplanar reconstructions (MPRs) slices. Material and Methods: Pre-treatment cone-beam computed tomography (CBCT) scans of 39 orthodontic patients aged between 8 and 13 years old were retrospectively chosen from the Department of Orthodontics and Dentofacial Orthopedics at the Lebanese University. PA cephalograms were reconstructed from CBCT scans. Skeletal landmarks were identified and analyzed on both imaging techniques using the Viewbox 4 cephalometric software. Results: For all eleven linear measurements (CoR, CoL, JR, JL, Me, CoAgR, CoAgL, CoMeR, CoMeL, AgMeR, AgMeL), two angular measurements (CoAgMeR, CoAgMeL), and six ratios (UFRa, LFRa, MxRa, MdRa, TMdRa, MxMdRa) showed a statistically significant difference between the CBCT constructed PA cephalograms and their respective three-dimensional (3D) volumes ( P < 0.05). Conclusion: PA reconstructions and MPR slices were not comparable according to Grummons’ analysis, especially for measurements evaluating the mandibular symmetry and point Juguale. New and reliable 3D analyses are recommended to account for accuracy and 3D reality.