Related Experiment Video
Updated: May 1, 2026
Quantitative Assessment Protocol for Facial Soft Tissue Volumetric Changes with Stereophotogrammetry
Published on: December 9, 2025
Validating the AFA3D forensic method using live CT data: A multiregional comparison of approximated and original
Renitta Rajan Thottungal1, Pierre Guyomarc'h2, Ján Dupej3
1Laboratory of 3D Imaging and Analytical Methods, Department of Anthropology and Human Genetics, Faculty of Science, Charles University, Prague, Czech Republic; Department of Anatomy, Third Faculty of Medicine, Charles University, Ruská 2411, Prague 100 00, Czech Republic.
Digital facial approximation methods like AFA3D show consistent regional errors, particularly in the nose and lower face. Further refinement is needed to improve accuracy for forensic identification of unknown individuals.
Area of Science:
- Forensic Anthropology
- Biometric Identification
- Digital Imaging
Background:
- Facial approximation aids identification in forensic and anthropological contexts.
- Digital methods aim to reduce subjectivity in estimating facial soft-tissue thickness (FSTT) and shape from skulls.
- Existing methods like AFA3D show persistent variability, especially in nasal and lower facial regions.
Purpose of the Study:
- To assess the performance of the AFA3D (Anthropological Facial Approximation in Three Dimensions) method.
- To evaluate the accuracy of AFA3D across diverse ethnic samples.
- To identify systematic regional errors in AFA3D predictions.
Main Methods:
- Comparison of AFA3D-generated faces with original facial meshes from 40 CT-scans (Czech, Slovak, Egyptian, French).
- Geometric morphometric analysis using Morphome3cs II.
- Evaluation of surface deviation within ±2.5 mm.
Main Results:
- 75.9-84.2% of facial surfaces fell within ±2.5 mm deviation across samples.
- Systematic regional errors were observed in the nose, lips, chin, cheeks, and upper face.
- Males exhibited greater localized discrepancies than females, linked to cranial structural differences.
Conclusions:
- AFA3D produces predictions with consistent regional error patterns.
- Refinement is needed for localized deviation mapping and posture influence modeling.
- Continued development of automated approximation methods is crucial for forensic reliability.
