An Assessment of How Facial Mimicry Can Change Facial Morphology: Implications for Identification.

The assessment of facial mimicry is important in forensic anthropology; in addition, the application of modern 3D image acquisition systems may help for the analysis of facial surfaces. This study aimed at exposing a novel method for comparing 3D profiles in different facial expressions. Ten male adults, aged between 30 and 40 years, underwent acquisitions by stereophotogrammetry ( VECTRA-3D ®) with different expressions (neutral, happy, sad, angry, surprised). The acquisition of each individual was then superimposed on the neutral one according to nine landmarks, and the root mean square ( RMS) value between the two expressions was calculated. The highest difference in comparison with the neutral standard was shown by the happy expression ( RMS 4.11 mm), followed by the surprised ( RMS 2.74 mm), sad ( RMS 1.3 mm), and angry ones ( RMS 1.21 mm). This pilot study shows that the 3D-3D superimposition may provide reliable results concerning facial alteration due to mimicry. [ABSTRACT FROM AUTHOR]