The visual perceptions of chin deviations in different facial types among orthodontists, orthodontic patients, and...

Multiple factors may influence the threshold at which chin deviation is detected and the point at which it is perceived as esthetically unacceptable. This study aimed to identify and compare the detection thresholds for chin deviation among orthodontists, orthodontic patients, and laypersons, and to assess how these thresholds vary across different facial types.

Photographs of a female subject were digitally manipulated to create 3 facial types (euryprosopic, mesoprosopic, and leptoprosopic) and 7 chin deviations ranging from 0° (no alteration) to 6° (most severe alteration). Evaluators assessed the attractiveness of each image using a visual analog scale and also determined whether treatment was needed. Responses were collected from orthodontists (n = 245), orthodontic patients (n = 443), and laypersons (n = 513). Analysis of variance, general linear model, and post-hoc tests were employed to determine the attractiveness ratings and diagnostic thresholds for chin asymmetries across different facial types.

All 3 evaluator groups rated 0° and 1° deviations as the most attractive across all facial types. Orthodontists were able to detect chin deviation at lower thresholds, 2° in the euryprosopic type, and 1° in the mesoprosopic and leptoprosopic types. Orthodontic patients identified chin deviations at 3° in euryprosopic and mesoprosopic types (male evaluators), and at 2° mesoprosopic (female evaluators) and leptoprosopic types. Laypersons detected chin deviations at the highest thresholds (ie, 4° in euryprosopic and 3° in both mesoprosopic and leptoprosopic types).

Orthodontists were the most perceptive evaluators, followed by orthodontic patients, whereas laypersons were the most lenient in their assessments. Facial type influenced the threshold at which chin deviations were perceived as unacceptable, with the euryprosopic facial type showing greater tolerance for chin deviation.