title: [Comparison of two kinds of methods evaluating the degree of facial asymmetry by three-dimensional data].
abstract: OBJECTIVE
  To compare two digital methods of quantitatively accessing the degree of facial asymmetry by three-dimensional data.
  
  
  METHODS
  The three-dimensional data of 20 subjects were got by the FaceScan, and then were input to the reverse engineering software Imageware 13.0 and Geomagic 12. Their mirror data were acquired and superimposed with the original data by the methods of interactive closest points (ICP) and Procrustes analysis (PA). The mid-sagittal planes of the two methods were extracted respectively, the degree of facial asymmetry and the distance of 21 automatic landmarks to mid-sagittal plane were calculated and compared.
  
  
  RESULTS
  The paired t test was taken and t=1.346, P=0.193.
  
  
  CONCLUSIONS
  We can safely come to the conclusions that for the subjects with no evident facial asymmetry, there are no significant difference between the PA and the ICP methods for extracting the mid-sagittal plane from three-dimensional data.
authors.affiliation: Center of Digital Dentistry, Peking University School and Hospital of Stomatology, Beijing 100081, China;Department of Prosthodontics, Peking University School and Hospital of Stomatology, Beijing 100081, China;National Engineering Laboratory for Digital and Material Technology of Stomatology, Peking University School and Hospital of Stomatology, Beijing 100081, China.
authors.forename: Y X
authors.initials: YX
authors.lastname: Xiong
authors.affiliation: Center of Digital Dentistry, Peking University School and Hospital of Stomatology, Beijing 100081, China;National Engineering Laboratory for Digital and Material Technology of Stomatology, Peking University School and Hospital of Stomatology, Beijing 100081, China.
authors.forename: H F
authors.initials: HF
authors.lastname: Yang
authors.affiliation: Center of Digital Dentistry, Peking University School and Hospital of Stomatology, Beijing 100081, China;National Engineering Laboratory for Digital and Material Technology of Stomatology, Peking University School and Hospital of Stomatology, Beijing 100081, China.
authors.forename: Y J
authors.initials: YJ
authors.lastname: Zhao
authors.affiliation: Center of Digital Dentistry, Peking University School and Hospital of Stomatology, Beijing 100081, China;Department of Prosthodontics, Peking University School and Hospital of Stomatology, Beijing 100081, China;National Engineering Laboratory for Digital and Material Technology of Stomatology, Peking University School and Hospital of Stomatology, Beijing 100081, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Wang
mesh_terms: D002508:Cephalometry; D005145:Face / Q000002:abnormalities*; D005146:Facial Asymmetry / Q000151:congenital*; D006801:Humans; D006965:Hyperplasia; D021621:Imaging, Three-Dimensional; D012984:Software