Reproducibility and reliability of three-dimensional soft tissue landmark identification using three-dimensional...

Area of Science:

• Craniofacial imaging
• Anthropometry
• Medical illustration

Background:

• Accurate soft tissue landmark identification is crucial for craniofacial analysis.
• Three-dimensional (3-D) stereophotogrammetry offers a precise method for capturing facial morphology.

Purpose of the Study:

• To assess the intraexaminer repeatability and interexaminer reproducibility of soft tissue landmarks using 3-D stereophotogrammetric images.
• To determine the clinical acceptability of landmark identification accuracy.

Main Methods:

• Thirty-four 3-D stereophotogrammetric images were analyzed.
• Nineteen soft tissue points were manually marked by two examiners on separate occasions.
• Intraclass correlation coefficients (ICCs) and kappa analysis were used to evaluate reliability and reproducibility.

Main Results:

• Most landmarks exhibited intraexaminer differences less than 1 mm, with good intraexaminer repeatability (ICCs 0.986-1.000).
• Interexaminer agreement was generally good, particularly along the z-axis, as indicated by kappa scores.
• Only the labiale superior landmark consistently showed differences under 0.5 mm.

Conclusions:

• Soft tissue landmarks on 3-D stereophotogrammetric images demonstrate clinically acceptable reproducibility, with most differences under 1 mm.
• While moderate reproducibility was observed for most landmarks, their accuracy is sufficient for clinical applications in craniofacial assessment.