Alrbata Raed H, Alfaqih Ayham Kh, Almhaidat Mohammad R, Al-Tarawneh Ahmad M
Orthodontic Department, Royal Medical Services, Amman, Jordan.
Int J Dent. 2020 Oct 17;2020:8946063. doi: 10.1155/2020/8946063. eCollection 2020.
To find thresholds at which laypersons and dental professionals perceive abnormalities in two facial frontal esthetics variables: facial symmetry and vertical harmony.
A baseline frontal image of a young male face with optimum facial proportions was generated from a real image using a photo editing software. Different facial asymmetry images were then generated from this image by manipulating the chin point position at 2 mm increment to the left side. Vertical harmony was perceived through manipulating lower anterior facial height (LAFH) at a ratio of 2% of increased and decreased heights. A total of 120 raters divided equally into four groups of laypersons, general dental practitioners (GDPs), orthodontists, and oral and maxillofacial surgeons (OMFSs) rated these images using an analog scale of 100 mm long. Using ANOVA and Tukey post hoc tests at < 0.05, the image that showed the first statistical difference compared to the baseline was considered as a threshold of abnormality.
The image of 4 mm asymmetry was defined by the laypersons and GDPs as the threshold of abnormality, while the orthodontists and OMFSs realized that at 2 mm. Laypersons and GDPs defined a threshold of 46% as an abnormal decrease in the LAFH and the other 2 groups at 48%. All dental professionals groups rated the image of 54% as an abnormal increase in the LAFH while laypersons perceived that at 56%.
These thresholds regarding frontal esthetics may contribute to the process of establishing proper orthodontic treatment planning that suits the highest facial esthetic standards.
确定外行人及牙科专业人员在面部正面美学的两个变量（面部对称性和垂直协调性）中感知异常的阈值。
使用照片编辑软件从一张真实图像生成一张面部比例最佳的年轻男性面部的基线正面图像。然后通过将下巴点位置向左以2毫米的增量进行调整，从该图像生成不同的面部不对称图像。通过以增加和减少高度的2%的比例调整下前面部高度（LAFH）来感知垂直协调性。总共120名评分者平均分为四组，即外行人、普通牙科医生（GDPs）、正畸医生和口腔颌面外科医生（OMFSs），使用100毫米长的模拟量表对这些图像进行评分。使用方差分析和Tukey事后检验（P<0.05），与基线相比显示出第一个统计学差异的图像被视为异常阈值。
外行人及GDPs将4毫米不对称的图像定义为异常阈值，而正畸医生和OMFSs则认为是2毫米。外行人及GDPs将LAFH降低46%定义为异常阈值，其他两组则为48%。所有牙科专业人员组将LAFH增加54%的图像评为异常，而外行人则认为是56%。
这些关于正面美学的阈值可能有助于制定符合最高面部美学标准的适当正畸治疗计划。
