title: Patterns of vertical facial growth in Korean adolescents analyzed with mixed-effects regression analysis.
abstract: BACKGROUND
  To understand the growth patterns of skeletal open bite and deepbite, we present observations from 9 years of pure longitudinal data based on lateral cephalometric radiographs using mixed-effects regression model analysis.
  
  
  METHODS
  In total, 51 children (14 years old) with extreme values for the ratio of lower anterior facial height to total anterior facial height were assigned to 1 of 2 groups: a skeletal open-bite group (11 boys, 14 girls) or a skeletal deepbite group (14 boys, 12 girls). Measurements of total anterior facial height, upper anterior facial height, lower anterior facial height, total posterior facial height, ramus height, and ratio of lower anterior facial height to total anterior facial height were obtained for all subjects. All data were analyzed and interpreted using a mixed-effects regression model analysis with random effects.
  
  
  RESULTS
  From these 4 groups at 14 years old, statistically significant differences were observed between the groups when subjects of the same sex were compared; however, statistical significance was not reached between subjects of opposite sexes in each group. Morphologic differences were clearly evident from the start and became more pronounced with age. There were statistical significances in the initial values and increases with age in all 6 variables except for increases with age in the ratio of lower anterior facial height to total anterior facial height. Statistical significance was also reached for morphologic differences between the annual increases in the ratio of lower anterior facial height to total anterior facial height and lower anterior facial height. In general, individual random variability was high in all variables when compared with the annual changes over time.
  
  
  CONCLUSIONS
  Divergent patterns were established early and became more pronounced with age, with anterior facial height dimensions primarily contributing to these differences. Individual variations were so pronounced that caution is recommended for all clinical decisions.
authors.affiliation: Department of Orthodontics, School of Dentistry, Seoul National University, Seoul, Korea.
authors.forename: Sung-Chul
authors.initials: SC
authors.lastname: Moon
authors.forename: Hong-Kyun
authors.initials: HK
authors.lastname: Kim
authors.forename: Taek-Ka
authors.initials: TK
authors.lastname: Kwon
authors.forename: Seong Ho
authors.initials: SH
authors.lastname: Han
authors.forename: Chang-Hyeon
authors.initials: CH
authors.lastname: An
authors.forename: Young-Seok
authors.initials: YS
authors.lastname: Park
mesh_terms: D000293:Adolescent; D000367:Age Factors; D002508:Cephalometry / Q000706:statistics & numerical data; D002680:Chin / Q000254:growth & development; D015331:Cohort Studies; D005147:Facial Bones / Q000254:growth & development*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008334:Mandible / Q000254:growth & development; D008335:Mandibular Condyle / Q000254:growth & development; D008437:Maxilla / Q000254:growth & development; D008445:Maxillofacial Development / Q000502:physiology; D009295:Nasal Bone / Q000254:growth & development; D024343:Open Bite / Q000503:physiopathology*; D057887:Overbite / Q000503:physiopathology*; D012044:Regression Analysis; D056910:Republic of Korea; D012658:Sella Turcica / Q000254:growth & development; D012737:Sex Factors; D014716:Vertical Dimension