一般注記Frontal cephalometric diagnosis that is used in examining maxillofacial symmetry is important in orthodontic treatment. Positioning of the head is important to ensure an accurate diagnosis. We compared the accuracy of positioning frontal cephalograms and frontal 3D-CT images. 3D-CT images were constructed using either a positioning method with an axis based on ear rods (method 1), or by using a positioning method with anatomical reference planes (method 2). We did cephalometric measurements and superimposition for comparison of five frontal cephalograms before and after orthodontic surgery and frontal 3D-CT images constructed by the two positioning methods. Significant errors were observed on frontal cephalograms (up to 11.5 mm) and also on the superimposition. In the 3D-CT images, both positioning methods had errors less than with the frontal cephalograms. Positioning method 2, which had a maximum error of 0.5 mm, had greater positioning precision than positioning method 1, which had a maximum error of 3.5 mm. It was also better with superimposition. The results suggest that 3D-CT images are superior to cephalograms. Positioning method 2, which has greater positioning precision, is very useful in constructing 3D-CT images.
2018年度
連携機関・データベース国立情報学研究所 : 学術機関リポジトリデータベース（IRDB）（機関リポジトリ）