Comparison of Three-Dimensional and Two-Dimensional Computed Tomography Scans for Cephalometric Mandibular Measurements in Thailand: A Retrospective Study

Objective: To evaluate whether 2D computerized tomography (CT) cephalometric measurements are comparable to 3D CT measurements of the mandible bone. Material and Methods: In this retrospective study, we collected data from patients who visited the emergency room of Songklanagarind Hospital between 2017 and 2020. A single operator identified 11 landmarks for cephalometric measurements in all images. Each image underwent three separate tracings, and subsequent repeated measurements were employed for further statistical analyses. Results: This study included 135 patients (87 males and 48 females). The mean age of the patients was 40.48±15 years. Nine of the eleven parameters showed a significant difference between the 2D and 3D cephalometric measurements (p-value<0.05). Male patients had a longer mandible than female patients, and there was a statistically significant size difference between the sexes (p-value<0.05), except for the mental foramen size (pair t-test >0.05). Length measurements displayed a statistically significant positive correlation with height and BSA (p-value<0.05), while no correlation was observed with body mass index (BMI) (p-value>0.05). Angle measurements did not exhibit any correlation with height, BSA, or BMI. Conclusion: In this study, 2D cephalometric measurements were significantly different from 3D CT measurements in each individual. Based on these findings, we recommend that surgeons should consider using 3D CT cephalometric measurements.