Comparative study between different groups of esthetic component of the Index of Orthodontic Treatment Need and eye tracking.

INTRODUCTION

The objective of this study was to determine how different people perceive distinct malocclusions with the use of eye tracking and to compare the results with scores from the subjective visual attractiveness scale (VAS) following 3 grades obtained from the Aesthetic Component of the Index of Orthodontic Treatment Need (AC-IOTN) scale.

METHODS

Ninety participants were equally distributed into 3 groups-dentists, orthodontists, and laypeople-and underwent 1 eye-tracking session. After being positioned and calibrated, they were shown 3 dental images. The images reflected the AC-IOTN grades of 1 (close to ideal), 5 (borderline need for treatment), and 8 (definite need for treatment). During the viewing, eye-tracker data were collected for fixation points, duration, and attractiveness (according to the VAS) for each image. The variables were statistically tested with the use of 2-way analysis of variance and complete factorial model (between groups, grades, and for the interactions between them).

RESULTS

Grade 1 received the highest subjective score independently from the participant group. This was in contrast to grades 5 and 8, which received similar scores, although the means of fixation points and duration were not significantly different among the grades (P > 0.05). The scores obtained from the dentist group were significantly higher than those from the other groups when the comparison was independent from the grade. In terms of fixation points, there were differences between dentists and orthodontists and between orthodontists and laypeople. The fixation point mean was higher for orthodontists than for dentists and was similar to that for laypeople.

CONCLUSIONS

Orthodontists were able to closely analyze the occlusal problems presenting with more severe malocclusions, and the specialists noticed more fixation points. Duration times, however, were not significantly different, because the orthodontists had greater interest, even in situations of unfavorable esthetics.