Evaluation of the impression imparted on others by a smile that shows the teeth,using the Semantic Differential Method

Abstract

We attempted to clarify how the impressions imparted on observers are affected by smiles with exposed teeth. Sixty young adults participated in the study, 23 men and 37 women, who had a mean age of 23±2 years. Impressions of composite (average) male and female faces were rated to eliminate individual bias. Ten facial photos were processed for each of 10 adult males with a mean age of 25±2 years and 10 adult females with a mean age of 26±1 years. Three stimulus images were used for each gender: a neutral face (teeth hidden), a smiling face (teeth hidden), and a grinning face (teeth exposed). The average male faces were rated by 30 subjects and the average female faces by the other 30. The semantic differential method was used to rate the impressions. Group ratings were then subjected to factor analysis. The two common factors having the greatest explanatory power were: “Sociable" and “Active" for the male stimulus images and “Friendly" and “Elegant" for the females. Significant differences between stimuli were observed for scores on both the first and second factors. In all cases, the grin was rated highest, followed by the smile and neutral face. We found that when smiling with the teeth exposed, male faces give a strong impression of sociability and activity, while females give a strong impression of friendliness and elegance. (J Osaka Dent Univ 2019; 53: 179‐186)