Reliability of a Portable Nonfixed Stereophotogrammetry System for Facial Imaging

Stereophotogrammetry (3D-SQ) provides a precise alternative for the assessment of facial aesthetic procedures. Nevertheless, its accuracy could be influenced by the operator when a nonfixed device is used. The objective of the present observational study was to evaluate the reliability of a portable nonfixed 3D-SQ device. Three operators took two 3-dimensional (3D) image captures of 3 distinct volunteers using a portable nonfixed 3D-SQ device. The acquisition of images was performed at 2 different time points (F1 and F2) with a 60 min interval between each capture for each volunteer. No external lights or tripod were utilized, as recommended by the manufacturer. The photographs were processed through specialized software to generate 3D models, and a specific region of the face was analyzed to assess the reliability of the method. Interclass correlation coefficients (ICCs) of the area, perimeter, and volume of the selected region were calculated. The results demonstrated a high intraoperator consistency at all 3 obtained values (volume ICCs = 0.829; area ICCs = 0.828; perimeter ICCs = 0.673). However, a low reliability in all values across different operators was found (ICCs < 0.5). These results suggest that variations in the captures may differ among different operators. These results may be attributed to factors such as the operator height, differences in reference points, or equipment stability. The study concluded that the reliability in facial stereophotogrammetry using a nonfixed device can be influenced by the operator, exhibiting high intraoperator reliability but significant variations between different operators. Level of Evidence: 4 (Therapeutic) For image description, please refer to the figure legend and surrounding text.