title: Use of 3-dimensional surface acquisition to study facial morphology in 5 populations.
abstract: BACKGROUND
  The aim of this study was to assess the use of 3-dimensional facial averages for determining morphologic differences from various population groups.
  
  
  METHODS
  We recruited 473 subjects from 5 populations. Three-dimensional images of the subjects were obtained in a reproducible and controlled environment with a commercially available stereo-photogrammetric camera capture system. Minolta VI-900 (Konica Minolta, Tokyo, Japan) and 3dMDface (3dMD LLC, Atlanta, Ga) systems were used. Each image 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 average composite faces of 1 man and 1 woman were achieved for each subgroup. These average facial composites were superimposed based on a previously validated superimposition method, and the facial differences were quantified.
  
  
  RESULTS
  Distinct facial differences were observed among the groups. The linear differences between surface shells ranged from 0.37 to 1.00 mm for the male groups. The linear differences ranged from 0.28 and 0.87 mm for the women. The color histograms showed that the similarities in facial shells between the subgroups by sex ranged from 26.70% to 70.39% for men and 36.09% to 79.83% for women. The average linear distance from the signed color histograms for the male subgroups ranged from -6.30 to 4.44 mm. The female subgroups ranged from -6.32 to 4.25 mm.
  
  
  CONCLUSIONS
  Average faces can be efficiently and effectively created from a sample of 3-dimensional faces. Average faces can be used to compare differences in facial morphologies for various populations and sexes. Facial morphologic differences were greatest when totally different ethnic variations were compared. Facial morphologic similarities were present in comparable groups, but there were large variations in concentrated areas of the face.
authors.affiliation: Department of Orthodontics, University of Alabama at Birmingham, Birmingham, AL 35294, USA. chung.h.kau@inbox.com
authors.forename: Chung How
authors.initials: CH
authors.lastname: Kau
authors.forename: Stephen
authors.initials: S
authors.lastname: Richmond
authors.forename: Alexei
authors.initials: A
authors.lastname: Zhurov
authors.forename: Maja
authors.initials: M
authors.lastname: Ovsenik
authors.forename: Wael
authors.initials: W
authors.lastname: Tawfik
authors.forename: Peter
authors.initials: P
authors.lastname: Borbely
authors.forename: Jeryl D
authors.initials: JD
authors.lastname: English
mesh_terms: D000293:Adolescent; D000328:Adult; D000465:Algorithms; D018912:Arabs / Q000208:ethnology*; D002508:Cephalometry / Q000379:methods; D004534:Egypt / Q000208:ethnology; D005145:Face / Q000033:anatomy & histology*; D005260:Female; D006801:Humans; D006814:Hungary / Q000208:ethnology; D021621:Imaging, Three-Dimensional / Q000379:methods*; D007834:Lasers; D008297:Male; D010780:Photogrammetry / Q000295:instrumentation; D012016:Reference Values; D017524:Slovenia / Q000208:ethnology; D013781:Texas / Q000208:ethnology; D014852:Wales / Q000208:ethnology; D044465:White People / Q000208:ethnology*; D055815:Young Adult