title: [Preliminary three-dimensional analysis of posed smile].
abstract: OBJECTIVE
  To analyze the changes in facial feature region during posed smile three dimensionally.
  
  
  METHODS
  The three-dimensional facial images during posed smiles and resting position in 44 volunteers (18 men, 26 women, 26.7 ± 2.6 years old) were acquired by using FaceScan optical three-dimensional sensor. These scanned three-dimensional images were processed and superimposed with commercially-available reverse modeling software. Quantitative and qualitative three dimensional analyses of changes in facial feature region during posed smile were done by using color maps.
  
  
  RESULTS
  The changing area accounted for (29.65 ± 8.40)% during posed smile, and the difference of the left and right half face was 6.69% (2.07%, 13.11%). Displacements in cheilion, zygomatic area, lower lip were detected in every subject during posed smile. Women [(4.49 ± 1.51) mm] gained more changes than men [(3.25 ± 1.75) mm] did in nasolabial fold.
  
  
  CONCLUSIONS
  Posed smile was asymmetric. Displacement variation and ratio are different at facial feature regions.Women shows greater changes around lips during posed smile.
authors.affiliation: Department of Orthodontics, Peking University School and Hospital of Stomatology & National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Li
authors.forename: Yi-Jiao
authors.initials: YJ
authors.lastname: Zhao
authors.forename: Yi
authors.initials: Y
authors.lastname: Liu
authors.forename: Yan-Heng
authors.initials: YH
authors.lastname: Zhou
mesh_terms: D000328:Adult; D004955:Esthetics, Dental; D005145:Face / Q000033:anatomy & histology*; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008046:Lip / Q000033:anatomy & histology; D008297:Male; D012737:Sex Factors; D012904:Smiling