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The Impact of Dentolabial Variables on Esthetic Perception: An Eye Tracking Study
F Hacıeyvazoğlu1, Ş E Doğan1, G Geduk2
1Department of Prosthodontics, Zonguldak Bülent Ecevit University, Zonguldak, Türkiye.
Objective:
This study evaluated how dentolabial variations (buccal corridor, occlusal plane, dental midline, and smile line) influence attention and aesthetic perception using Likert scales and eye-tracking.
Methods:
The buccal corridor, frontal occlusal plane, dental midline, and smile line parameters were modified using Adobe Photoshop CC 2019 (San Jose, California). Modified smile photographs featured four parameters: buccal corridor width (5%, 10%, 15%, 25%), occlusal plane angle (0°, 2°, 4°, 6°), dental midline deviation (0-3 mm), and smile line level (-2 mm to + 4 mm). Participants, 189 Turkish dental students (118 female, 71 males; mean age = 24.1), evaluated these images for esthetics using a Likert scale. Eye-tracking recorded total fixation duration (TFD), first fixation duration (FFD), and visit count (VC) for specific areas of interest (AOIs). Data were analyzed using the Kolmogorov-Smirnov and Friedman tests.
Results:
The smile region focused attention most at 5% and 25% buccal corridor widths, where both FFD and VC were the highest (P < 0.001), suggesting that extreme corridor widths (narrow or wide) draw more focus. In contrast, the 15% buccal corridor width showed the lowest TFD, yet received the highest aesthetic ratings, indicating a more visually comfortable and less attention-demanding appearance. Increased occlusal plane angles (4° and 6°) correlated with lower aesthetic scores, and no significant differences in TFD, FFD, or VC were found across these angulations. Greater midline deviations (+2 mm and + 3 mm) shortened FFD but increased VC (P = 0.01; P < 0.001), indicating more frequent attention returns to pronounced asymmetry. While + 4 mm gingival display garnered the longest TFD (P = 0.013), it had the lowest aesthetic ratings, showing that excessive exposure attracts focus through visual irregularity rather than appeal.
Conclusion:
As deviations from ideal dentolabial parameters increased, first fixation times decreased, suggesting quicker visual responses to noticeable discrepancies. Simultaneously, aesthetic ratings declined, reflecting reduced attractiveness. Increased fixation time and visit count indicated that more significant deviations generated sustained and repeated attention.
