The effect of the change of facial appearance caused by denture condition to their esthetic appraisal.

本研究探讨无牙患者在佩戴不同的全口义齿后，如何以自然外观的概念作为面部美学的指标来评价其面部外观的美学。材料为无牙患者佩戴不同实验全口义齿的两种面部图像。一种材料是二维人脸图像，由一对人脸的正面和侧面视图组成；另一组是在X、Y和Z轴上旋转的三维面部图像。使用美国评分（0-10）对面部图像进行评价，0为非自然，10为自然。实验义齿具有4种唇支撑状态和3种咬合垂直尺寸（OVD）。前段可调整，可提供四种唇支撑条件：(1)LO：标准唇支撑，(2)L-5：咬合切缘r m （IEOR）后咬合口5 mm， (3) L+5：咬合口前咬合口5 mm， (4) Ln：无前咬合缘。后段可调节，给出三种OVD条件：(1)VO：标准OVD， (2) V-5：比VO小5mm， (3) L+5：比LO大5mm。在31张图像中，标准唇托（LO）和标准OVD （VO）的评分高于其他条件。小OVD （V-5）评分低于大OVD (V+5)，无唇托（Ln）评分极低。在二维图像中，LOVO表现出较高的得分，而其他图像则随着条件的变化而没有表现出趋势。结果表明，根据标准唇托和OVD制作的全口义齿对面部美观是有益的。无牙患者似乎很难通过二维图像来了解自己的面部外观。

This study investigated how edentulous patients rate the esthetics of their facial appearance wearing different complete dentures using the concept of natural appearance as an index of facial esthetics. The materials were two kinds of facial images on an edentulous patient wearing different experimer tal complete dentures. One kind of materials was 2-dimensional (2D) facial images which consisted of one pair of frontal and profile views of the faces; the other was three-dimensional (3D) facial images which were rotated on their X, Y and Z axis. The face images were appraised using a n americ scale (0-10), 0 is unnatural and 10 is natural. The experimental dentures had four states of lip support and three occlusal vertical dimensions (OVD). The anterior part could be adjusted to give four conditions of lip support: (1) LO: standard lip support, (2) L-5: incisal edge of occlusion r m (IEOR) 5 mm posterior to LO, (3) L+5: IEOR 5 mm anterior to LO, (4) Ln: without the anterior occlusion rim. The posterior part could be adjusted to give three conditions of OVD: (1) VO: standard OVD, (2) V-5: 5 mm smaller than VO, (3) L+5: 5 mm larger than LO.In the 31) images standard lip support (LO) and standard OVD (VO) showed higher score than the others conditions. The smaller OVD (V-5) rated lower seore than larger OVD (V+5), and no lip support (Ln) showed very low score than another conditions. In the 2D images LOVO showed higher score but others did not showed tendency according to the change of condition. These results indicated that complete dentures fabricated according to the standard lip support and OVD are useful for esthetic of facial appearance. It seems difficult for edentulous patients to apprise their facial appearance using 2D images.