title: Three-dimensional interpretation of intercanine width change in children: a 9-year longitudinal study.
abstract: BACKGROUND
  The immutability of intercanine width has long been the subject of discussion. The aims of this study were to describe the longitudinal intercanine width changes of children from 6 to 14 years of age and to interpret them with a 3-dimensional method.
  
  
  METHODS
  Complete dental stone casts were annually prepared for 66 subjects (50 girls, 16 boys) from 6 to 14 years of age. By using 3-dimensional laser scanning and reconstruction software, virtual casts were constructed. Intercanine width was measured as well as the related 3-dimensional measurements, such as the area of the intercanine triangle, the intercanine angle, the radius of the inscribed circle, and the angles formed by the virtual axes of the canines and the occlusal plane. The measurement changes over time were analyzed by using mixed-effects analysis for longitudinal data.
  
  
  RESULTS
  There were slight decreases in intercanine widths for both sexes and both arches. However, the amounts of change were relatively small when compared with the initial values and individual random variability. The values of area, the angles formed by the virtual axes of the canines and the occlusal plane, and the radius showed decreasing trends, whereas the intercanine angle exhibited increasing trends during the observation period. Although the intercanine width changed over time, it was not clinically significant, showing relative stability.
  
  
  CONCLUSIONS
  The intercanine width of an untreated subject after stabilization in the mouth is considered to be quite stable, even though individual variation is great.
authors.affiliation: Department of Dental Biomaterials Science, Dental Research Institute and School of Dentistry, Seoul National University, Korea.
authors.forename: Jin-Soo
authors.initials: JS
authors.lastname: Ahn
authors.forename: Moon-Soo
authors.initials: MS
authors.lastname: Park
authors.forename: Hyun-Suk
authors.initials: HS
authors.lastname: Cha
authors.forename: Hyun Chul
authors.initials: HC
authors.lastname: Song
authors.forename: Young-Seok
authors.initials: YS
authors.lastname: Park
mesh_terms: D000293:Adolescent; D002508:Cephalometry / Q000379:methods / Q000706:statistics & numerical data; D002648:Child; D003198:Computer Simulation; D003481:Cuspid / Q000033:anatomy & histology*; D003724:Dental Arch / Q000254:growth & development*; D003818:Dentition, Mixed; D019229:Dentition, Permanent; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D016013:Likelihood Functions; D008137:Longitudinal Studies; D008297:Male; D003765:Models, Dental; D012016:Reference Values; D012727:Sex Characteristics; D012984:Software