Pilot Study for Validation of Stereophotogrammetric and Mobile LiDAR Facial Scanning Against Vernier Caliper...

Facial scanning devices are widely used in dentistry, but their accuracy needs improvement. This study developed a portable face scanning application (named Face Rebuilder) for iPhone/iPad and compared its accuracy to that of a commercially available handheld 3-dimensional (3D) facial scanner based on stereophotogrammetry (DS-FSCAN, Hangzhou, China). It has not been commercially released. Twenty-two volunteers were recruited. Eighteen markers were affixed to each volunteer's face, and the accuracy of the facial scanning systems was evaluated by measuring the distances between these markers. Direct physical measurements using a vernier caliper (GREENER IP54, Shandong, China) served as the reference measurement for accuracy assessment. Two groups were compared: study group (Face Rebuilder) and control group (DS-FSCAN). The absolute deviations from the reference measurement were calculated. The data analysis comprised the Shapiro-Wilk test for normality assessment, followed by the Mann-Whitney U test for group comparisons. No significant difference (p > 0.05) was observed between the proposed method and the stereophotogrammetry-based facial scanning method. The bias value for the proposed method was 0.945 ± 0.765 mm, whereas that of the stereophotogrammetry-based method was 1.006 ± 0.787 mm. The portable 3D scanning method based on LiDAR achieved high-precision face-scanning data acquisition, when using a Vernier caliper as reference measurement.