title: Comparison Between Interactive Closest Point and Procrustes Analysis for Determining the Median Sagittal Plane of Three-Dimensional Facial Data.
abstract: OBJECTIVE
  To compare 2 digital methods to determine median sagittal plane of three-dimensional facial data-the interactive closest point algorithm and Procrustes analysis.
  
  
  METHODS
  The three-dimensional facial data of the 30 volunteers were got by the Face Scan 3D optical sensor (3D-Shape GmbH, Erlangen, Germany), and then were input to the reverse engineering software Imageware 13.0 (Siemens, Plano, TX) and Geomagic 2012 (Cary, NC). Their mirrored data were acquired and superimposed with the original data by the methods of interactive closest points and Procrustes analysis. The median sagittal planes of the 2 methods were extracted from the original and mirrored facial data respectively, 3 asymmetry indices were measured for comparison. Differences between the facial asymmetry indices of the 2 methods were evaluated using the paired sample t-test.
  
  
  RESULTS
  In terms of the 3 asymmetry indices, there were no significant differences between interactive closest points and Procrustes analysis for extracting median sagittal plane from three-dimensional facial data.(t = 0.0.060, P = 0.953 for asymmetry index (AI) 1, t = -0.926, P = 0.362 for AI 2, t = 1.1172, P = 0.0.251 for AI 3).
  
  
  CONCLUSIONS
  In this evaluation of 30 subjects, the Procrustes analysis and the interactive closest point median-sagittal planes were similar in terms of the 3 asymmetry indices. Thus, Procrustes analysis and interactive closest point can both be used to abstract median sagittal plane from three-dimensional facial data.
authors.affiliation: *Center of Digital Dentistry †Faculty of Prosthodontics, Peking University School and Hospital of Stomatology ‡National Engineering Laboratory for Digital and Material Technology of Stomatology §Research Center of Engineering and Technology for Digital Dentistry, Ministry of Health, Beijing, China.
authors.forename: Yuxue
authors.initials: Y
authors.lastname: Xiong
authors.forename: Yijiao
authors.initials: Y
authors.lastname: Zhao
authors.forename: Huifang
authors.initials: H
authors.lastname: Yang
authors.forename: Yucun
authors.initials: Y
authors.lastname: Sun
authors.forename: Yong
authors.initials: Y
authors.lastname: Wang
mesh_terms: D000328:Adult; D000465:Algorithms; D059925:Anatomic Landmarks / Q000033:anatomy & histology; D002508:Cephalometry / Q000706:statistics & numerical data*; D005145:Face / Q000033:anatomy & histology*; D005146:Facial Asymmetry / Q000473:pathology; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000706:statistics & numerical data*; D021621:Imaging, Three-Dimensional / Q000706:statistics & numerical data*; D008953:Models, Anatomic; D061848:Optical Imaging / Q000706:statistics & numerical data; D012984:Software; D055815:Young Adult
references.citation: Angle Orthod. 2006 May;76(3):388-93
references.pmid: 16637716
references.citation: J Orofac Orthop. 2007 Nov;68(6):477-90
references.pmid: 18034288
references.citation: J Orofac Orthop. 2008 Jul;69(4):268-82
references.pmid: 18797831
references.citation: J Anat. 2008 Dec;213(6):663-9
references.pmid: 19094182
references.citation: Clin Oral Investig. 2012 Feb;16(1):285-94
references.pmid: 21271348
references.citation: Am J Orthod Dentofacial Orthop. 2005 Oct;128(4):424-30
references.pmid: 16214622
references.citation: Angle Orthod. 1981 Jan;51(1):70-7
references.pmid: 6939355
references.citation: Angle Orthod. 1991 Spring;61(1):43-8
references.pmid: 2012321
references.citation: J Oral Maxillofac Surg. 1994 Nov;52(11):1126-32
references.pmid: 7965306
references.citation: J Anat. 1995 Feb;186 ( Pt 1):103-10
references.pmid: 7649806
references.citation: Int J Neurosci. 2005 Aug;115(8):1165-73
references.pmid: 16040358
references.citation: Eur J Orthod. 2014 Apr;36(2):125-32
references.pmid: 21795753