Section of Orthodontics, Dental School, Federal University of Bahia, Salvador, Bahia, Brazil.
Am J Orthod Dentofacial Orthop. 2013 May;143(5):658-64. doi: 10.1016/j.ajodo.2013.02.013.
Our objective was to determine the perception of smile esthetics among orthodontists and laypeople with respect to asymmetries on the maxillary incisor edges in a frontal smile analysis.
Two frontal close-up smile photos of 2 women, 1 white and 1 Afro-Brazilian, were selected for this study. Both smiles displayed healthy maxillary anterior dentitions. The images were digitally altered to create tooth wear on the maxillary left central and lateral incisors in 0.5-mm increments. The final images were randomly assembled into a photo album that was given to 120 judges, 60 orthodontists and 60 laypersons. Each rater was asked to evaluate the attractiveness of the images with visual analog scales. The data collected were statistically analyzed with 1-way analysis of variance with the Tukey post-hoc test and the unpaired Student t test.
The most attractive smiles in both types of smiles were those without asymmetries and the 0.5-mm wear in the lateral incisor. In general, tooth wear was considered unattractive by both groups of raters following a pattern: the more tooth wear, the more unattractive the smile; tooth wear in the central incisor was considered more unattractive than in the lateral incisor. For both group of raters, 0.5 mm of wear in the central incisor was considered unattractive, whereas the thresholds for lateral incisor discrepancies were 0.5 mm for orthodontists and 1.0 mm for laypersons.
The result of this study corroborates the clinical assumption that symmetry between the maxillary central incisors is a paramount goal for esthetic treatments.
我们的目的是确定正畸医生和非专业人士在正面微笑分析中对上颌切牙边缘不对称的微笑美学感知。
选择了 2 名女性（1 名白人，1 名非裔巴西人）的 2 张正面特写微笑照片进行本研究。这两个微笑都展示了健康的上颌前牙列。通过数字手段对图像进行修改，在上颌左侧中切牙和侧切牙上制造 0.5mm 递增的牙齿磨损。最终的图像被随机组合成一个相册，分发给 120 名评判者，其中 60 名为正畸医生，60 名为非专业人士。每个评判者都被要求使用视觉模拟量表评估图像的吸引力。收集的数据采用单因素方差分析与 Tukey 事后检验和未配对学生 t 检验进行统计学分析。
在这两种微笑类型中，最吸引人的微笑是没有不对称和侧切牙 0.5mm 磨损的微笑。总的来说，两组评判者都认为牙齿磨损不美观，遵循的模式是：磨损越多，微笑越不美观；中切牙的牙齿磨损比侧切牙更不美观。对于两组评判者，中切牙 0.5mm 的磨损被认为不美观，而侧切牙差异的阈值对于正畸医生是 0.5mm，对于非专业人士是 1.0mm。
本研究结果证实了临床假设，即上颌中切牙之间的对称性是美学治疗的首要目标。
