Esthetic evaluation of dynamic smiles with attention to facial muscle activity

Am J Orthod Dentofacial Orthop. 2013 Jun;143(6):819-27. doi: 10.1016/j.ajodo.2013.01.017.


Introduction: Numerous studies of smile esthetics have used still photos. Photos, however, do not capture the dynamics of a smile, an element that can contribute to overall smile esthetics. In this study, we assessed the esthetics of dynamic smiles.

Methods: Four facially balanced female dental students were trained to produce 8 distinct smiles using the facial action coding system. Videos of the models' whole faces were presented to 2 panels of raters: dental students and nondental undergraduate students. Smile attractiveness was rated using a Web-based survey.

Results: The smile that used 4 labial muscles was rated significantly better than the smile involving only the risorius muscle (P <0.05). The orbicularis oculi improved smile attractiveness (P <0.04), especially among smiles rated less favorably (P <0.05). Visibility of the models' eyes, however, did not influence the ratings (P >0.05), perhaps because orbicularis oculi activation altered activations in other muscles in such a way that smile attractiveness was increased in the lower face.

Conclusions: Smile esthetics increased with increased recruitment of muscles involved in smile production. The results were robust across the models, suggesting that objective rating methods of smile-dynamic esthetics could become an important clinical tool.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Beauty
  • Cheek / physiology
  • Dentists
  • Esthetics, Dental*
  • Eye
  • Facial Muscles / physiology*
  • Female
  • Humans
  • Lip / physiology
  • Male
  • Mouth / physiology
  • Oculomotor Muscles / physiology
  • Smiling / physiology*
  • Students, Dental
  • Videotape Recording
  • Young Adult