Department of Orthodontics, Dental Clinic of the Medical Faculty, University of Würzburg, Germany.
Eur J Orthod. 2011 Dec;33(6):647-53. doi: 10.1093/ejo/cjq146. Epub 2011 Feb 25.
In orthodontic diagnosis, facial symmetry is important. The aim of the present study was to analyse the perception of various degrees of facial asymmetry exhibited by carefully designed virtual three-dimensional (3D) material. Three groups of raters (30 orthodontists, 30 maxillofacial surgeons, and 30 laymen) rated, using a six-point scale, the degree of asymmetry of eight randomly presented 3D faces exhibiting incremental soft tissue alterations. The faces were created by gradually transforming the nose or chin in increments of 2 mm away from the computed symmetry plane. Differences between the groups in analysis of facial asymmetry, the rating of facial stimulus, and right and left facial asymmetry were determined using a t-test. The results demonstrated that raters' profession did not influence the point at which they identified asymmetry. Even laymen were able to detect asymmetries when located near the midline of 3D faces. All raters identified asymmetries of the nose as more negative than those of the same degree of the chin. A left-sided deviation of the nose along the facial symmetry plane lead to a more negative rating of facial appearance, whereas a right-sided deviation of the chin was rated as less attractive. Nasal architecture plays a crucial role in the perception of symmetry. These findings provide clinicians with a greater understanding of how faces are perceived, a process which is of particular interest in treating orthognathic patients, and those with congenital anomalies.
在正畸诊断中，面部对称性很重要。本研究旨在分析精心设计的虚拟三维（3D）材料所展示的不同程度的面部不对称感知。三组评价者（30 名正畸医生、30 名颌面外科医生和 30 名非专业人士）使用六点量表对 8 张随机呈现的 3D 面部照片的不对称程度进行了评价，这些照片的软组织逐渐改变，增量为 2 毫米，偏离计算的对称平面。使用 t 检验确定了组间在面部不对称分析、面部刺激评价以及左右面部不对称方面的差异。结果表明，评价者的职业并不影响他们识别不对称的程度。即使是非专业人士也能够在 3D 面部的中线附近检测到不对称。所有评价者都认为，与同等程度的下巴不对称相比，鼻子的不对称更为负面。鼻子沿面部对称平面的左侧偏斜会导致更负面的面部外观评价，而下巴的右侧偏斜则被认为不那么有吸引力。鼻子的结构在对称性感知中起着至关重要的作用。这些发现为临床医生提供了对面部感知的更深入了解，这一过程对于治疗正颌患者和先天性畸形患者特别重要。
