title: [The characteristics of the arch form of skeletal Class II malocclusion].
abstract: OBJECTIVE
  To study the characteristics of the arch form of skeletal Class III malocclusion and provide references for diagnosis and treatment plan.
  
  
  METHODS
  7 indexes in dental casts of 47 patients with skeletal Class III malocclusion and 50 individuals with normal occlusion were measured respectively. And differences between corresponding upper and lower measurements were calculated. Independent samples t-test was employed for comparing between the two groups by SPSS 17.0.
  
  
  RESULTS
  Compared with normal occlusion sample, Class III malocclusion group had smaller anterior segment lengths and larger canine angles (P<0.05). Differences between upper and lower first premolar widths were larger in males with skeletal Class III malocclusion. And differences between upper and lower anterior segment lengths were smaller in males with skeletal Class III malocclusion (P<0.05).
  
  
  CONCLUSIONS
  Arch widths of patients with skeletal Class III malocclusion are basically normal. The lengths of anterior segment are smaller and the anterior arch forms are straighter.
authors: Graduate School of Tianjin Medical University, Tianjin 300070, China.
authors: Liuzhen
authors: L
authors: Sun
authors: Xiangfei
authors: X
authors: Fan
authors: Danna
authors: D
authors: Xiao
authors: Hui
authors: H
authors: Gao
mesh_terms: D001641:Bicuspid; D003724:Dental Arch; D003766:Dental Occlusion; D005260:Female; D006801:Humans; D008297:Male; D008312:Malocclusion, Angle Class II; D008313:Malocclusion, Angle Class III