title: [Analysis of the plaster casts of Class II division 1 non-extraction patients treated with Alexander technique].
abstract: OBJECTIVE
  To investigate the changes of arch width and arch length in Class II division 1 non-extraction patients treated with Alexander technique.
  
  
  METHODS
  Dental casts of 21 Class II division 1 non-extraction patients treated with Alexander appliance were taken before (T1) and after treatment (T2). All the casts were laser scanned. The arch width and arch length were digitally measured. The differences of arch width and arch length between T1 and T2 were recorded and analyzed.
  
  
  RESULTS
  The upper arch length decreased from (32.82 ± 2.51) mm to (31.97 ± 2.17) mm (P < 0.05). The lower arch length increased from (27.53 ± 2.61) mm to (28.80 ± 1.81) mm (P < 0.05). The intercanine width in the upper arch changed significantly from T1 to T2. The intermolar width in the upper and lower arches increased significantly from T1 to T2.
  
  
  CONCLUSIONS
  Class II division 1 non-extraction patients could be treated successfully by increasing the upper arch width.
authors: Department of Orthodontics, Peking University School and Hospital of Stomatology, Beijing 100081, China.
authors: Tian
authors: T
authors: Cao
authors: Song
authors: S
authors: Wei
authors: Yan-heng
authors: YH
authors: Zhou
mesh_terms: D000293:Adolescent; D000328:Adult; D002370:Casts, Surgical; D002508:Cephalometry; D002648:Child; D003724:Dental Arch / Q000033:anatomy & histology*; D005260:Female; D006801:Humans; D008297:Male; D008312:Malocclusion, Angle Class II / Q000628:therapy*; D003765:Models, Dental; D009971:Orthodontics, Corrective / Q000379:methods*; D055815:Young Adult