Are there ethnic differences of facial movements between Europeans and Asians?

Abstract

Due to the widespread use of Free Functional Muscle Transplant (FFMT) around the world to reanimate the paralysed face, it is important to be aware of ethnic differences in facial movements. Participants in this study were born in Taiwan (n=24) and Austria (n=24). Analyses were conducted applying the digitised three-dimensional video-analysis system. All 48 subjects have never undergone any treatments in the face nor did they have previous histories of craniofacial anomalies. In general, Europeans were observed to have larger facial movements than Asians, from 0.4 mm (e.g. 5.7%) up to 3.9 mm (e.g. 30.3%), on average 1.3 mm+/-0.82 SD (e.g. 20.6%). Particularly the eyebrow, nose and mouth regions show statistically significant larger excursions on average 1.4 mm (e.g. 19.9%), 1.3 mm (e.g. 34.6%) and 3.0 mm (e.g. 30.3%). One exception is in the eye region, where Asians have a larger excursion (1.4 mm, e.g. 15.8%) of the eyelids, due to the larger distances between the upper and lower eyelids in the rest position. Europeans have generally larger facial movements than Asians. Particularly the eyebrow, nose and mouth regions show statistically significant larger excursions; exception must be made to the eye region, where Asians have a larger excursion of the eyelids. This is the first step to gather essential information about the ethnical differences in facial movements, a factor that should be considered as FFMT is becoming more popular worldwide.