Valencia University Medical and Dental School, University of Valencia, Valencia, Spain.
Department of Dentistry, Universidad Europea de Valencia. Faculty of Health Sciences, Valencia, Spain.
BMC Oral Health. 2020 Feb 6;20(1):42. doi: 10.1186/s12903-020-1031-y.
A number of reference patterns such as the interincisal line, curve of the upper lip, width of the smile or shape of the teeth have been studied in different populations. Determining the frequency of different smile aesthetic parameters in a European Caucasian population and exploring possible gender differences is important in order to obtain predictable treatment outcomes.
Photographs were obtained under resting and forced smiling conditions in 140 individuals (70 males and 70 females) with a mean age of 20.1 ± 4.3 years. Different variables were recorded, including the position of the maxillary interincisal midline in relation to the facial midline, the arc and width of the smile, and the shape of the teeth. The data were processed using the SPSS version 15.0 statistical package, with application of the chi-squared test and a confidence level of 95%. The statistical power was 80%, and the level of significance 5% (α = 0.05).
A total of 94.3% of the sample presented a maxillary interincisal midline coinciding with the facial midline, and 80% had a consonant smile line. The curve of the upper lip was upwards in 47.1% of the cases, followed by a straight curve in 41.4%. Most of the subjects (84.3%) presented a medium smile line with tooth exposure to the second premolar (61.4%). There were no significant differences between males and females.
The integration of aesthetic criteria is needed in order to guarantee satisfactory and predictable dental treatment outcomes. There were no statistically significant differences between males and females. The maxillary interincisal midline coincided with the facial midline, with a consonant smile arc and a medium smile line, upward lip curve and oval tooth shape.
许多参考模式，如切牙中线、上唇曲线、微笑宽度或牙齿形状，已经在不同人群中进行了研究。确定欧洲白种人群中不同微笑美学参数的频率，并探索可能的性别差异，对于获得可预测的治疗效果非常重要。
在 140 名年龄在 20.1±4.3 岁的个体（男性 70 名，女性 70 名）的休息和强制微笑状态下获得照片。记录了包括上颌切牙中线相对于面部中线的位置、微笑的弧度和宽度以及牙齿形状等不同变量。使用 SPSS 版本 15.0 统计软件包处理数据，应用卡方检验，置信水平为 95%。统计功效为 80%，显著性水平为 5%（α=0.05）。
样本中共有 94.3%的上颌切牙中线与面部中线重合，80%的人有一致的微笑线。上唇曲线向上的有 47.1%，其次是直线的有 41.4%。大多数受试者（84.3%）的中微笑线与第二前磨牙的牙齿暴露程度为 61.4%。男性和女性之间没有显著差异。
为了保证令人满意和可预测的牙齿治疗效果，需要综合美学标准。男性和女性之间没有统计学上的显著差异。上颌切牙中线与面部中线重合，微笑弧一致，中微笑线，上唇曲线向上，牙齿形状为椭圆形。
