A survey study on the evaluation of posed smiles by social group

Abstract

Abstract Background Smiling, one of the main facial expressions, expresses positive emotions that promote psychological well-being and facilitate individuals’ acceptance of society. Smiles can influence others’ perceptions of facial attractiveness. The purpose of this study was to compare the effect of the perception of smiling structures on the attractiveness of smiles among raters in different groups. Methods Smile photographs were selected and digitally manipulated to determine changes in various smile aesthetic parameters (the lip thickness ratio, smile line/ smile index, lower upper lip curve, and smile arc/dental curvature). These altered images were rated by Chinese participants stratified by social group: dentists, clinicians, nurses, and nonmedical professionals. A total of 1469 subjects were recruited to complete the questionnaire. Smile strength scores were calculated, and comparisons between groups were made. Results All respondents chose a 1:1.5 lip thickness ratio, average smile line, upwards upper lip curvature and a consonant smile arc parallel to the lower lip curvature smile arc. However, significant differences were detected in the rating scores across occupational groups. Conclusions The smile variables of the lip thickness ratio, smile line, upper lip curvature, and smile arc are predominant factors influencing smile attractiveness and should be given priority when considering and managing aesthetic treatment plans. In addition, it is necessary to account for the influence of profession on individuals’ evaluations and to conduct individualized evaluation and treatment.