3-dimensional Facial Morphology of Adults and Children in Different Populations

Objectives: Average faces can be created from 3-dimensional (3D) photographs to compare the facial morphological differences between various populations and genders. The objective of this study was to evaluate the differences in facial morphologies of children and adults from African-American and Welsh populations.
Methods: The faces of 171 children and 217 adults from the two populations were captured using 3dMDface^TM system (3dMD LLC, Atlanta, USA) and 3D images were developed by means of stereophotogrammetry and structured light technology. Using Rapidform software (INUS Technology, Seoul, Korea), images were aligned on a previously tested algorithm to generate a facial average for male and female in each subgroup. By fine registration, the eight average facial shells were superimposed onto one another, and linear measurements and color histograms were produced to compare and analyze differences in facial morphology.
Results: A total of 12 pairs of comparison were established and the means of absolute linear measurements ranged from 0.42mm (African-American-Children-female vs. African-American-Children-male) to 1.66mm (Welsh-male-Children vs. Welsh-Male-Adult). An interesting finding was that the mean differences between female and male was also small in Welsh-children (0.46mm), while increased in adults from both populations (1.18mm for African-American, 1.29 for Welsh).The mean differences between age-gender-specific groups were 1.10mm for African-American-female vs. Welsh-female and 0.96mm for African-American-male vs. Welsh-male in children, while 1.24mm and 1.25mm in adults, respectively. Color map surface-to-surface comparison revealed a distinct facial differences in children from the two different races as well as adults. The ala, alar base, and paranasal areas were increased anteroposteriorly during growth in the both populations, and the diversity between different genders in the same races revealed.
Conclusions: The use of 3D facial averages is a powerful tool to determine morphologic differences from various populations and to evaluate normal facial development.