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Objective: To compare the difference in type and quantity of asymmetry between Class I, Class II, and Class III sagittal skeletal patterns using geometric morphometrics. Methods: Surface models were constructed from pre-treatment three-dimensional CBCT scans of 144 patients (41 males, 103 females) randomly selected from the database at the University of California, San Francisco, Division of Orthodontics. There were a total of 62 skeletal Class I (0≤ANB≤4), 63 skeletal Class II (ANB>4), and 19 skeletal Class III (ANB

Introduction: Proper diagnosis and treatment planning is essential to the outcome of orthodontic therapy with accurate diagnostic records being the pinnacle of that process. Previously, two-dimensional imagery has been the standard in analyzing or visualizing a patient for skeletal asymmetries but has numerous limiting factors. The limitations that two dimensional analyses face can be solved by the use of three-dimensional cone beam computed tomography (CBCT) when combined with an efficient and relevant analysis. The purpose of this study was to design a novel analysis of asymmetry utilizing CBCT that could be used in a standard orthodontic diagnostic analysis. Methods: CBCT images of 35 patients from the UCSF Orthodontic Clinic were used for development of the analysis. A pilot study with 5 patients having marked asymmetries was traced at 3 different time points to aid in landmark verification and assess reliability. A series of landmarks sharing commonalities with those used in two-dimensional cephalometric analysis were applied. A Pearson Correlation Coefficient with Bonferonni correction as well as a Bland-Altman test for reproducibility was applied for the three timepoints on five different patients to test intraobserver reliability. 10 patients with a molar Class I malocclusion, 10 patients with CII malocclusions, and 10 with CIII malocclusions were used to create a sample of patients with the applied orientation method and asymmetry analysis. Results: Landmark identification was found to be reproducible with only a weak statistical difference in landmark identification. No statistically significant differences were found between any landmarks and their different timepoint selections, particularly those points essential to the establishment of the analysis axis (p