The Perception of Asymmetries in Occlusal Plane in the Frontal View among Laypeople: An Eye-tracking Study

Abstract

Introduction: Eye-tracking studies have explored the need for orthodontic treatment and treatment outcomes from a lay perspective as a newer diagnostic tool versus traditional assessments based on static photographs. Aim: To evaluate the visual aesthetic perceptions of laypeople with regard to occlusal plane cant in a frontal smile analysis. Materials and Methods: Images of smiling male and female faces had occlusal plane cant added with Photoshop CC on the magnitudes of 0°, 2°, and 2.5° to the left side on the female face and the male to the right side. To obtain eye-tracking data, two software programs, OGAMA and The Eye Tribe Tracker®, were used together. Thirty male and 30 female laypeople raters were selected from the student population of a university (Pontifícia Universidade Católica do Paraná) and consisted of undergraduate students and not those of dentistry, to visualise ocular movement in the Areas of Interest (AOI). A One-Way Analysis of Variance (ANOVA) was applied to compare one of the independent variables with the dependent variable. Results: Eye-tracking showed that the laypeople identified a triangle shape between the right eye, left eye, and mouth with greater fixation of the eyes. There were statistically significant differences according to the number of fixations at the mouth and menton. Conclusion: Laypeople were not able to perceive the occlusal plane cant located on the right side of the male face or to the left on the female face. However, it is important to do take the laypeople perspective into consideration when making treatment alternatives.

Keywords

• asymmetry
• frontal smile
• occlusal cant