Kuruhan Mesude Sinem, Çoban Büyükbayraktar Zeynep
Bülent Baydaş Private Orthodontics Oral and Dental Health Polyclinic, Bursa, Turkey.
Department of Orthodontics, Sivas Cumhuriyet University Faculty of Dentistry, Sivas, Turkey.
Am J Orthod Dentofacial Orthop. 2025 Apr;167(4):425-435. doi: 10.1016/j.ajodo.2024.10.020. Epub 2024 Dec 21.
This study aimed to evaluate maxillary dental midline shifts and mandibular asymmetries created in different amounts and directions on photographs taken from 7 different angles by different groups and to determine acceptable esthetic limits.
Photographs of a female model in a social smile position were taken from 7 different angles (0° [frontal], 15°, 30°, and 45° on the right and left sides) and digitally modified for maxillary dental and mandibular midline deviations at specified degrees using Adobe Photoshop. To enable participants to evaluate the photographs sequentially, the photographs were transformed into videos using Adobe Premiere Pro software. The videos were rated by 188 participants (48 orthodontists; 49 dentists; 45 esthetic, plastic, and reconstructive surgeons; and 46 laypersons) using the visual analog scale (VAS) in a survey. An analysis of variance test was used to compare VAS scores among raters, and the Bonferroni test was used to compare VAS scores among the groups.
The threshold for the acceptability of maxillary dental midline shifts was 2 mm for orthodontists; dentists; and esthetic, plastic, and reconstructive surgeons but 4 mm for laypersons. Although laypersons were unable to perceive changes in mandibular asymmetry between 0°-6°, the threshold was 3° for other groups. For participants in which mandibular asymmetries and maxillary dental midline shifts were in opposite directions, the threshold for all groups was 6°. For participants in which lower jaw asymmetries and maxillary dental midline shifts were in the same direction, the threshold value for orthodontists was 6°. Other groups could not perceive variables related to asymmetry.
More sensitive esthetic assessments can be made by evaluating smile esthetics from different angles. Mandibular asymmetries are considered more esthetically acceptable than maxillary dental midline shifts. In mandibular asymmetry and maxillary dental midline shifts, deviations in the same direction are more esthetically acceptable than deviations in opposite directions. Orthodontists are able to notice small changes in mandibular asymmetry.
本研究旨在评估不同组从7个不同角度拍摄的照片中所产生的不同程度和方向的上颌牙中线偏移和下颌不对称情况，并确定可接受的美学限度。
对一名处于社交微笑姿势的女性模型从7个不同角度（0°[正面]、左右两侧15°、30°和45°）进行拍照，并使用Adobe Photoshop软件对照片进行数字修改，使其产生特定度数的上颌牙和下颌中线偏差。为了让参与者能够依次评估照片，使用Adobe Premiere Pro软件将照片转换为视频。在一项调查中，188名参与者（48名正畸医生；49名牙医；45名美容、整形和重建外科医生；46名外行人）使用视觉模拟量表（VAS）对视频进行评分。采用方差分析检验比较评分者之间的VAS分数，并使用Bonferroni检验比较各组之间的VAS分数。
正畸医生、牙医以及美容、整形和重建外科医生可接受的上颌牙中线偏移阈值为2mm，而外行人的阈值为4mm。尽管外行人无法察觉0°至6°之间的下颌不对称变化，但其他组的阈值为3°。对于下颌不对称和上颌牙中线偏移方向相反的参与者，所有组的阈值均为6°。对于下颌不对称和上颌牙中线偏移方向相同的参与者，正畸医生的阈值为6°。其他组无法察觉与不对称相关的变量。
通过从不同角度评估微笑美学，可以进行更敏感的美学评估。下颌不对称比上颌牙中线偏移在美学上更易被接受。在下颌不对称和上颌牙中线偏移中，方向相同的偏差比方向相反的偏差在美学上更易被接受。正畸医生能够注意到下颌不对称的微小变化。
