The Study of Morphological Differences in Populations

OBJECTIVES: The aim of this paper was to assess the use of 3D facial averages in determining facial morphological differences from two Caucasian population groups.

METHODS: 3D images were obtained under a reproducible and controlled environment from a commercially available stereo-photogrammetric camera capture system. The 3dMD system photographed 200 subjects from two population groups (Hungarian and Houston) and each population group was made up of 50 males and 50 females, aged between 18-30 years. Each individual face was obtained as a facial mesh and orientated along a triangulated axis. All faces were overlaid one on top of the other and a complex mathematical algorithm was performed until an average composite face of one male and female was achieved for each sub-grouping (HunM – Hungarian Males, HunF-Hungarian Females, HouM- Houston Males and HouF – Houston Females). These average facial composites were superimposed onto one another (HunM versus HouM and HunF and HouF) based on a previously validated superimposition method, and the facial differences were quantified.

RESULTS: Distinct facial differences were observed between the population groups. These differences could be seen in the nasal, malar, lips and lower facial regions). In general, the mean facial differences between the Hungarian and Houston females were 0.55± 0.59mm whilst the differences in Hungarian and Houston males were 0.44 ± 0.42mm respectively. The range of differences for the female population pairings and male population pairings were -2.02 to 3.78 mm and -2.02 to 2.12 mm respectively.

CONCLUSIONS: 3D facial averages representing the facial soft tissue morphology of adults in populations may be used to assess diagnostic and treatment regimes for patients according to populations. Each population is different with respective to the make-up of their soft tissue structures and traditional soft tissue normative data (eg: Caucasian Norms) should be altered and applied for population specific groups.