Ear Size and Position Variations Rated by Casual Observers on Artificial Intelligence-Generated Models.

Area of Science:

• Facial aesthetics
• Perceptual science
• Plastic surgery

Background:

• Auricular asymmetry significantly impacts facial aesthetics.
• The perception threshold for auricular asymmetry by casual observers is not well-defined.

Purpose of the Study:

• To quantify casual observer perception of ear size, angulation, protrusion, and vertical position.
• To establish perception thresholds for different types of auricular asymmetry.

Main Methods:

• Utilized AI-generated facial images with controlled unilateral variations in ear size, angulation, protrusion, and vertical position.
• 200 participants rated 46 images on a 0-10 Likert scale for ear appearance.

Main Results:

• A size change of ≥10% was perceived as significantly different (p < 0.001).
• Retrograde angulation of ≥10° and anterograde angulation of 20° were perceived as significantly different (p < 0.001).
• Positive protrusion asymmetry was perceived more severely than negative protrusion asymmetry; vertical position changes were least critically perceived.

Conclusions:

• Casual observers are more sensitive to auricular size and retrograde angulation asymmetries.
• Perception of ear protrusion and vertical position asymmetry is less critical to observers.