Smile shape and self-perceived smile attractiveness.

Area of Science:

• Facial aesthetics
• Anthropometry
• Psychometrics

Background:

• Self-perceived smile attractiveness is a key aspect of facial aesthetics.
• Understanding the geometric determinants of smile attractiveness can inform cosmetic and orthodontic treatments.

Purpose of the Study:

• To investigate the relationship between three-dimensional smile shape and self-perceived attractiveness in young adults.
• To determine if this relationship differs between males and females.

Main Methods:

• 601 young adults had their smiles captured using 3D stereophotogrammetry.
• Smile shape was analyzed using 62 landmarks and principal component analysis (PCA).
• Multivariate regression models assessed the association between smile shape and self-rated attractiveness, controlling for allometric effects.

Main Results:

• No significant association between smile shape and attractiveness was found in males.
• In females, a significant association was observed, with wider and taller smiles perceived as more attractive.
• After controlling for facial size (allometry), the significant association in females became non-significant, though a moderate effect persisted.

Conclusions:

• Smile shape, particularly proportional width and height, influences perceived attractiveness in females.
• Facial size significantly impacts the perception of smile attractiveness.
• Sex-based differences in aesthetic self-perception and a preference for broader smiles are suggested.