Measuring asymmetry from high-density 3D surface scans: An application to human faces

Area of Science:

• Human Anatomy
• Developmental Biology
• Biometrics

Background:

• Bilateral symmetry is optimal for development; deviations indicate developmental instability.
• Fluctuating Asymmetry (FA) measures these deviations and is linked to health and attractiveness.
• Previous facial asymmetry studies used limited 2D landmarks, lacking precision.

Purpose of the Study:

• To develop and validate a novel protocol for measuring human facial asymmetry using high-density 3D scans.
• To improve the accuracy and comprehensiveness of Fluctuating Asymmetry (FA) assessment.
• To automate the process of facial asymmetry measurement, reducing manual labor.

Main Methods:

• Utilized high-density 3D facial scans and a spatially dense anthropometric mask.
• Employed Iterative Closest Point (ICP) registration for non-rigid mask mapping.
• Validated mapping precision using 19 manually indicated landmarks.

Main Results:

• The 3D protocol provides a more accurate assessment of FA compared to 2D methods.
• Spatially dense measurements yield superior accuracy in asymmetry calculation.
• The protocol generates an integrated asymmetry estimate across the entire face.

Conclusions:

• High-density 3D scanning offers a significant advancement in measuring facial asymmetry and developmental instability.
• The automated protocol enhances efficiency and accuracy in biometric research.
• This method provides a more reliable tool for studying the links between asymmetry, health, and attractiveness.