Evaluation of the effect of trimline types of clear aligners on esthetic perception using eye-tracking technology and visual analog scale

• Published in: American journal of orthodontics and dentofacial orthopedics Vol. 168; no. 2; pp. 243 - 252
• Main Authors: Kurnaz, Merve, Bayam, Nuray Akbıyık, Öztürk, Semir, Biren, Sibel
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.08.2025
• Subjects: Adult; Dentistry; Esthetics, Dental; Eye-Tracking Technology; Female; Humans; Male; Visual Analog Scale; Young Adult
• ISSN: 0889-5406; 1097-6752; 1097-6752
• DOI: 10.1016/j.ajodo.2025.03.007

This study aimed to compare the impact of clear aligners with different edge finishes on esthetic perception across various specialties, using eye-tracking technology and the visual analog scale. Three different trimlines are designed at the gingival border: short scallop, straight, and straight extended. The designed aligners were taken in the mouth without a retractor, in a dark environment with a softbox. The prepared images were turned into a survey via the Google Docs document service. The survey questioning esthetic success according to a 5-point Likert scale was sent to the participants via the online channel. Eye tracking will also take place online with Sticky (version 1.4, Tobii Pro Lab; Tobii Technology AB, Danderyd, Sweden), the online form of the Tobii X2-60 eye-tracking software. The data obtained in this study were analyzed using the SPSS software (version 22; IBM, Armonk, NY). Mann-Whitney U test and Kruskal-Wallis H test with Bonferroni correction were used. No significant difference was observed among the specialties in terms of scores (P >0.05). In both male and female subjects, all surfaces showed significant differences across trimlines for the number of fixations, number of visits, and time viewed. In addition, Region 2 exhibited significant differences in the number of fixations, number of visits, and time until noticed (P <0.05). In males, region 3 showed significant differences across trimlines for the number of fixations, number of visits, and time viewed (P <0.05). In females, time until noticed also differed significantly (P <0.05). In both male and female subjects, region 4 showed significant differences across trimlines for the number of fixations, number of visits, and time viewed (P <0.05). No differences were found among the specialty groups using the conventional survey method. Scalloped and straight trimlines were generally noticed. •There were no differences in esthetic perception among specialties in the visual analog scale.•Differences were observed in the evaluation of close-up smiles between different genders.•The straight and scallop trimlines are generally more noticeable.