Vectra H2^® stereophotogrammetry system evaluation for 3D facial analysis in children

Facial anthropometric analysis is a valuable tool for assessing growth and development in children. It allows for continuous patient monitoring, facilitates the identification of morphological variations and asymmetries, supports diagnostic processes, contributes to the planning and predictability of therapeutic interventions, and aids in evaluating treatment outcomes. This study aimed to evaluate Vectra H2^® stereophotogrammetry system for facial anthropometry analysis in children.

Thirty participants were selected, ranging from 5 to 12 years old. Prior to the acquisition of facial images, nineteen anatomical landmarks were marked with a black eyeliner pen on the participants' faces, so that 14 linear measurements could be quantified. The three-dimensional (3D) image of the facial surface was captured using the stereophotogrammetry equipment. First, linear measurements were quantified directly on the participant's face using a digital caliper. In the second phase of the anthropometric analysis, the same linear measurements were taken on the 3D image using stereophotogrammetry system software. Intraclass correlation coefficient (ICC) test was applied to evaluate intra- and inter-examiner errors. For data analysis, Pearson's and Spearman's correlation coefficient tests were applied. The mean absolute difference (MAD) was used to describe the differences. Data were presented as mean/standard deviation and median/interquartile deviation.

All 14 facial measurements showed statistically significant difference (P<0.05). The measurements Tr-G, G-Pn, G-Sn, Ene-Che, and End-Chd demonstrated very strong correlation (r values between 0.9485 and 0.9026), while Ald-Ale, Exe-Che, Sn-Ls, Sn-Pg, Ls-Li, Exd-Chd, and Chd-Che measurements exhibited strong correlation (r values between 0.8821 and 0.7094). Acd-Ace and Cphe-Cphd measurements showed moderate correlation (r=0.5790 and r=0.6982). The measurements Sn-Ls and Ene-Che presented a lower MAD value (0.53), and the measurements Ald-Ale showed the highest value (5.38).

Vectra H2^® facial stereophotogrammetry system proved to be a validated and reliable method for facial anthropometry analysis in children.