Cranio-facial Morphology Analysis using CT

For each patient, pre-treatment and post-treatment CT were performed with a CT system (Alphard-3030, Asahi Roentgen Ind. Co., Ltd., Kyoto, Japan) under the following roentgenographic conditions: 60–110 kV; 3–15 mA; collimation, 0.6 mm; rotation time, 18 s; lamination thickness, 0.39 mm. A series of images was treated using Dolphin Imaging (Dolphin Imaging & Management Solutions, Verona, Italy) for orthodontic diagnosis and treatment planning. Contiguous CT images were compiled, 3D frontal sinus models were constructed, and volume-rendered images were extracted. Furthermore, lateral cephalometry was performed at the pre-treatment and post-treatment stages using a roentgenographic system (Hyper-X CM, Asahi Roentgen Ind. Co., Ltd.). All radiographs were performed in the standing position with maximum intercuspation.
Cephalometric tracing for all patients was performed on tracing paper by one examiner (M.S.). Nineteen landmarks were plotted using Dolphin Imaging by another examiner (S.S.) to measure craniofacial morphology. The validity and reproducibility of the plots were verified by other orthodontic experts who participated in this research as collaborators. All examiners were blinded to the general status of the participants. To examine the intra-examiner reliability of cephalometric measurements, one examiner traced five randomly selected cephalograms before measurement and plotted three arbitrary points (nasion, sella, and pogonion) twice within an interval of one week. The intraclass correlation coefficient (ICC) was calculated using SPSS 27.0 (SPSS Inc., Chicago, IL, USA). The ICC was 0.977 (0.957–0.988: 95% confidence interval), confirming the strong reliability of the selected measurements.