title: Dental arch changes from 22 to 43 years of age: are they different in individuals with high versus low mandibular plane angle?
abstract: OBJECTIVE
  To investigate whether individuals with high and low mandibular plane angles, respectively, have different patterns of long-term dental arch changes in adulthood.
  
  
  METHODS
  The material comprised 16 low-angle (≤ 24.4 degree) and 10 high-angle individuals (≥38.7 degree). Mean age was 22.7 years when the first recordings were made (T1), and new recordings were made 10 (T2) and 20 (T3) years later. The individuals were orthodontically untreated except for three who had been out of retention for more than 5 years before T1. Lateral cephalograms and study casts were obtained on all three occasions.
  
  
  RESULTS
  For the total observation period, the greatest mean changes were observed as a 1mm decrease of lower intercanine width and arch depths in both groups. Intermolar widths increased less than 0.5mm. Upper and lower crowding increased in the range of 0.5-0.7mm in the two groups. Only small changes occurred in overjet and overbite. Differences between groups were not significant except for lower anterior arch depth which decreased more in the low-angle group, and overjet which increased in the high- and decreased in the low-angle group. During both periods the changes were generally in the same direction.
  
  
  CONCLUSIONS
  Changes in dental arch dimensions from third to fifth decade of life are small and generally similar in individuals with high versus low mandibular plane angles. The changes are for most variables in the same direction in the two periods examined. The only significant differences between the groups are the changes in lower arch depth and overjet.
authors.affiliation: *Department of Orthodontics, University of Oslo, Faculty of Dentistry, Oslo, Norway.
authors.forename: Olav
authors.initials: O
authors.lastname: Bondevik
authors.affiliation: *Department of Orthodontics, University of Oslo, Faculty of Dentistry, Oslo, Norway.
authors.forename: Lisen
authors.initials: L
authors.lastname: Espeland
authors.affiliation: *Department of Orthodontics, University of Oslo, Faculty of Dentistry, Oslo, Norway arild.stenvik@odont.uio.no.
authors.forename: Arild
authors.initials: A
authors.lastname: Stenvik
mesh_terms: D000328:Adult; D002508:Cephalometry / Q000379:methods; D003481:Cuspid / Q000033:anatomy & histology; D003724:Dental Arch / Q000033:anatomy & histology / Q000254:growth & development*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008310:Malocclusion / Q000473:pathology; D008334:Mandible / Q000033:anatomy & histology / Q000254:growth & development*; D008437:Maxilla / Q000033:anatomy & histology / Q000254:growth & development*; D003765:Models, Dental; D008963:Molar / Q000033:anatomy & histology; D057887:Overbite / Q000473:pathology; D055815:Young Adult