上下顎移動術による中顔面軟組織の三次元表面形状変化―非接触型レーザー三次元形状計測装置を用いて

Abstract

In severe skeletal mandibular prognathism with soft tissue distortion, maxillary advancement, combined with mandibular set-back operation, is frequently performed to improve facial esthetics. However, few studies have been reported on the three-dimensional soft tissue changes following two-jaw surgery in Japanese subjects. Therefore, we used a threedimensional non-contact laser scanner (VIVID700®MINOLTA) to assess presurgical and postsurgical soft tissue changes, focused on the midface. Subjects constituted five female prognathtic patients without facial asymmetry, who had received sagittal split ramus and Le Fort I osteotomies at Niigata University Dental Hospital. All cases received their preoperative and postoperative orthodontic treatment by the standard edgewise system. To standardize the scanning procedure, the VIVID700 was fixed by a special metal frame, ear rods were used to stabilize the head, and the FH plane was kept horizontal. The scanner allowed a single scan in 0.6 seconds. Presurgical and postsurgical images were taken and processed; 16 horizontal and 17 sagittal lines were constructed and were used to produce an average face for each stage. Average form showed little change in the upper region of the cheek, while the lower region of the cheek became full. In the nose area, the nose tip moved anterior and coronal, and the nasal breadth tended to widen. The upper lip moved anterior, on average.In conclusion, although the main aim of maxillary advancement is to improve midfacial fullness, the concomitant nasal changes should be considered, and its effect on treatment outcome be ascertained.