Abstract
BACKGROUND: The desire for a youthful smile is not limited by age, as individuals seek it throughout their lifetime. Aging affects the components of a smile; accordingly, this study assessed the perspectives of laypeople towards the morphological traits of a youthful smile on the frontal view. In this psychometric study, a 26-year-old female with a normal face, normal occlusion, teeth alignment, and no previous cosmetic surgery was employed as the photo model; sixteen smile images were obtained via Adobe Photoshop by varying incisal display, vertical step between maxillary central and lateral incisor, smile arch form, and buccal corridor size. The prepared photos were given to the layperson participants using an online questionnaire for age estimation. RESULTS: A total of 195 laypersons participated in the study. The results revealed that a 2 mm reduction, 4 mm increase, and 4 mm reduction in incisor display would increase the age estimation (P-Value<0.001). Futher, 1 mm reduction, a 0.5 mm reduction, and 0.5 mm increase in vertical step would contribute to overestimation of the age (P-Value<0.001). Additionally, the smile arc's reversed, straight, and moderate convexity increased the age estimation (P-Value<0.001). Regarding buccal corridor size, 1- and 2-mm reduction plus 2-mm increase resulted in age estimates significantly older than the original image (P-Value<0.001). CONCLUSION: Perceptions of youthfulness are influenced by morphological traits such as incisor display, vertical step between central and lateral, smile arch form, and buccal corridor size.