Three-Dimensional Anthropometric Facial Analysis and Fitting Discrepancies Between Stereophotogrammetry and CT

Area of Science:

• Anthropometry
• Medical Imaging
• Biotechnology

Background:

• Investigated the reliability and repeatability of stereophotogrammetry and computed tomography (CT) in 3-dimensional anthropometric facial analysis.
• Explored the clinical application of supine CT for facial measurements.

Purpose of the Study:

• To compare the reliability and accuracy of 3D CT and 3dMD stereophotogrammetry for facial anthropometric analysis.
• To identify optimal landmark points for registration in 3D facial analysis.

Main Methods:

• 20 healthy volunteers underwent 3D CT and 3dMD stereophotogrammetry.
• Measurements included facial landmarks (Al-Al), width (Go-Go, Zy-Zy, Ex-Ex), and height (Sn-Gn).
• Intraclass correlation coefficient (ICC) assessed interrater reliability; paired t-analysis evaluated intramethod displacement.

Main Results:

• Alare, nasion, and pronasale points showed minimal positional influence, recommended for registration.
• CT exhibited good interrater reliability across all indicators.
• Stereophotogrammetry showed ICC < 0.75 for Go-Go and Zy-Zy. Significant differences (P < 0.05) between CT and stereophotogrammetry were found for En-En, Ex-Ex, and Go-Go, with CT yielding a larger Go-Go measurement by 2.34 mm.

Conclusions:

• Both CT and stereophotogrammetry are reliable for facial soft tissue evaluation.
• The Go-Go measurement discrepancy is attributed to positional variations, facial expressions, and gravity.
• Careful consideration of these factors is crucial when evaluating the mandibular angle region.