Three-dimensional analysis of facial morphology

The objectives of this study were to evaluate sexual dimorphism for facial features within Chinese and African American populations and to compare the facial morphology by sex between these 2 populations.

Three-dimensional facial images were acquired by using the portable 3dMDface System, which captured 189 subjects from 2 population groups of Chinese (n = 72) and African American (n = 117). Each population was categorized into male and female groups for evaluation. All subjects in the groups were aged between 18 and 30 years and had no apparent facial anomalies. A total of 23 anthropometric landmarks were identified on the three-dimensional faces of each subject. Twenty-one measurements in 4 regions, including 19 distances and 2 angles, were not only calculated but also compared within and between the Chinese and African American populations. The Student's t-test was used to analyze each data set obtained within each subgroup.

Distinct facial differences were presented between the examined subgroups. When comparing the sex differences of facial morphology in the Chinese population, significant differences were noted in 71.43% of the parameters calculated, and the same proportion was found in the African American group. The facial morphologic differences between the Chinese and African American populations were evaluated by sex. The proportion of significant differences in the parameters calculated was 90.48% for females and 95.24% for males between the 2 populations. The African American population had a more convex profile and greater face width than those of the Chinese population.

Sexual dimorphism for facial features was presented in both the Chinese and African American populations. In addition, there were significant differences in facial morphology between these 2 populations.