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

这项研究调查了无牙颌患者如何评价他们戴着不同全口义齿的面部外观的美感，使用自然外观的概念作为面部美观的指标。实验材料为无牙颌患者戴着不同实验者全口义齿的两种面部图像。一种材料是由一对人脸的正面图和侧面图组成的二维(2D)人脸图像，另一种是沿X、Y和Z轴旋转的三维(3D)人脸图像。脸部图像用十进制(0-10)进行评价，0表示不自然，10表示自然。实验义齿有四种唇托状态和三种咬合垂直尺寸(OVD)。(1)LO：标准唇托；(2)L-5：咬合切缘，LO后5 mm；(3)L+5：LO前5 mm；(4)Ln：无咬合前缘。调整后部可得到3种情况：(1)VO：标准OVD；(2)V-5：比VO小5 mm；(3)L+LO：5：5 mm。较小的OVD(V-5)的评分低于较大的OVD(V+5)，而无唇托(Ln)的评分低于其他条件。在2D图像中，LOVO表现出较高的得分，而其他人则没有随着条件的变化而表现出趋势性。这些结果表明，按照标准唇托和OVD制作的全口义齿具有良好的面部美观效果。对于无牙患者来说，使用2D图像来评估自己的面部外观似乎很困难。

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.