Procedure for the systematic orientation of digitised cranial models. Design and validation

Area of Science:

• Forensic Anthropology
• 3D Imaging Technology
• Biomedical Engineering

Background:

• Systematic orientation of bony pieces is crucial for accurate comparative analysis.
• Current orientation methods for 3D surface-scanned models, especially in forensic contexts, often lack high accuracy and are operator-dependent.
• Standardized alignment of cranial models is essential for reliable anthropological assessments.

Purpose of the Study:

• To develop and evaluate a systematic, assisted orientation method for aligning 3D cranial models.
• To achieve accurate cranial model orientations independent of operator and anthropological expertise.
• To enhance the reliability of 3D surface scanning in forensic applications.

Main Methods:

• Utilized four human crania of known age and sex.
• Scanned and reconstructed crania using an Eva Artec™ portable 3D surface scanner.
• Determined cranial landmarks using Rhinoceros 3D software with three different operators, comparing manual versus assisted orientation methods.

Main Results:

• Intra-observer analysis indicated improved orientation accuracy with the assisted method compared to manual orientation.
• Inter-observer analysis revealed that experienced evaluators using the assisted method achieved comparable or superior accuracy to manual methods.
• Inexperienced evaluators demonstrated significantly more accurate orientations with the assisted method.

Conclusions:

• The developed assisted orientation method provides precise, systematic, and automated spatial orientations for virtual cranial models.
• This innovative system reduces operator dependency and variability in cranial model alignment.
• The method offers a reliable tool for forensic anthropology, improving the consistency of 3D cranial analyses.