A geometric morphometric validation study of computed tomography-extracted craniofacial landmarks.

Area of Science:

• Forensic Anthropology
• Medical Imaging
• Anatomical Measurement

Background:

• Accurate craniofacial landmark data is crucial for forensic identification and clinical applications.
• Traditional methods involve direct digitization of dry skulls, while computed tomographic (CT) scans offer a non-invasive alternative.
• Understanding variations between these data acquisition methods is essential for reliable analysis.

Purpose of the Study:

• To investigate and quantify the variation between craniofacial landmarks derived from CT scans and direct digitization of dry skulls.
• To assess the reliability of CT-derived landmarks for forensic and clinical use.
• To identify specific landmarks or regions exhibiting significant differences between the two methods.

Main Methods:

• Thirteen traditional craniofacial landmarks were extracted from CT scans using Aviso software.
• Coordinates from CT scans were compared with coordinates from direct digitization of dry skulls.
• Statistical analysis, including principal component analysis, was employed to evaluate similarities and differences.
• Comparisons were performed on combined samples and individual specimens.

Main Results:

• A statistically significant difference (P = 0.0223) was observed in the overall dataset, with the first principal component explaining 23.97% of the variation attributed to data acquisition methods.
• Differences were more pronounced along midline landmarks.
• Individual specimen comparisons showed variation in symmetric landmarks, but no significant differences were found between CT and direct digitization (P = 0.9883).
• Bilateral coordinates did not show significant differences in either analysis (P = 0.4165).

Conclusions:

• While overall dataset differences suggest further exploration of reference frames and sample composition for combined CT and digitized data, individual specimen comparisons validate CT-extracted landmarks.
• CT-extracted craniofacial landmarks are deemed useful for putative identifications in forensic settings.
• The findings support the clinical applicability of CT-derived landmarks for anatomical measurements and assessments.