title: Classification of facial asymmetry by cluster analysis.
abstract: BACKGROUND
  The purposes of this study were to classify patients with facial asymmetry by using the cluster analysis and to evaluate the characteristics of the resultant groups.
  
  
  METHODS
  One hundred consecutive orthodontic patients who had frontal cephalograms and photographs taken for the diagnosis of facial asymmetry were included in the sample. A cluster analysis was used to classify the subjects, with craniofacial measurements related to asymmetry obtained from the cephalograms and photographs.
  
  
  RESULTS
  The subjects were divided into 5 clusters based on only 3 variables from the frontal cephalograms: menton deviation, apical base midline discrepancy, and vertical difference of right and left antegonion. The results of the ANOVA test according to the variables showed statistically significant differences between the groups in all variables, indicating that each group can be easily identified with the variables.
  
  
  CONCLUSIONS
  The results suggest that patients with facial asymmetry can be classified simply based on some variables on frontal cephalograms, and this classification can be helpful in proper diagnosis and treatment planning for these patients.
authors.affiliation: Department of Orthodontics, 2nd Stage of Brain Korea 21, School of Dentistry, Dental Science Research Institute, Chonnam National University, Gwangju, Korea. hhwang@chonnam.ac.kr
authors.forename: Hyeon-Shik
authors.initials: HS
authors.lastname: Hwang
authors.forename: Il-Sun
authors.initials: IS
authors.lastname: Youn
authors.forename: Ki-Heon
authors.initials: KH
authors.lastname: Lee
authors.forename: Hoi-Jeong
authors.initials: HJ
authors.lastname: Lim
mesh_terms: D000293:Adolescent; D000704:Analysis of Variance; D002508:Cephalometry; D016000:Cluster Analysis; D003769:Dental Occlusion, Traumatic / Q000150:complications; D005146:Facial Asymmetry / Q000145:classification* / Q000209:etiology; D005260:Female; D006801:Humans; D008297:Male; D008334:Mandible / Q000503:physiopathology