Sakellaropoulos Orestes, Lagouvardos Panagiotis
Int J Esthet Dent. 2020;15(2):158-172.
The lightness of teeth and the distances of the upper and lower lip from the maxillary cervical and incisal lines are factors that correlate with smile attractiveness.
This study investigates the degree of association of the above factors with smile attractiveness and evaluates the possible effect of evaluators' gender, age, occupation, and education level on the perception of smile attractiveness.
An almost perfect smile of an adult Caucasian female was altered to create various smile images with differences in lightness of teeth and upper and lower lip positions. The images were randomly assembled in three slides of four, seven, and five images each and presented to 130 participants to evaluate the most attractive smile (MAS) and the least attractive smile (LAS). Data collected were analyzed for differences between gender, age, occupation, and education level as regards the evaluation of the MAS and LAS using the chi-square test with a significance level of α = 0.05.
Statistical analysis showed that the smile images in L1 and L2 were equally considered to be the most attractive smiles. The chi-square test indicated no differences between all groups (P > 0.05). Percentages for the most attractive smiles for the lower lip positions were almost equal for most positions of the upper lip, with differences only between age groups (P > 0.05). The least attractive smiles were those with the upper lip position at 3 mm above the cervical line, with differences only between occupation groups (P < 0.001).
The results of this study indicate that lightness of teeth positively affects smile attractiveness. Lower lip positions with a distance of 0 to 1 mm from the maxillary incisal line are considered more attractive. Upper lip distances were strongly associated with smile attractiveness. Gender, occupation, and education level did not differently affect the perception of attractiveness due to lower lip positions, but age did.
牙齿的亮度以及上、下唇与上颌牙颈线和切缘线的距离是与微笑吸引力相关的因素。
本研究调查上述因素与微笑吸引力的关联程度，并评估评估者的性别、年龄、职业和教育水平对微笑吸引力感知的可能影响。
改变一名成年白人女性几乎完美的微笑，以创建牙齿亮度和上、下唇位置不同的各种微笑图像。这些图像被随机组装在三张幻灯片中，每张幻灯片分别有四张、七张和五张图像，并呈现给130名参与者，以评估最具吸引力的微笑（MAS）和最不具吸引力的微笑（LAS）。使用α = 0.05显著性水平的卡方检验，对收集到的数据进行分析，以比较性别、年龄、职业和教育水平在MAS和LAS评估方面的差异。
统计分析表明，L1和L2中的微笑图像被同等认为是最具吸引力的微笑。卡方检验表明所有组之间没有差异（P > 0.05）。上唇大多数位置的下唇位置对于最具吸引力微笑的百分比几乎相等，仅年龄组之间存在差异（P > 0.05）。最不具吸引力的微笑是上唇位置在牙颈线以上3毫米处的微笑，仅职业组之间存在差异（P < 0.001）。
本研究结果表明，牙齿亮度对微笑吸引力有积极影响。下唇与上颌切缘线距离为0至1毫米的位置被认为更具吸引力。上唇距离与微笑吸引力密切相关。性别、职业和教育水平对由于下唇位置导致的吸引力感知没有不同影响，但年龄有影响。
