title: [Heritability analysis on skeletal angle III malocclusion].
abstract: OBJECTIVE
  To explore the significance of genetic factor in the pathogenesis of skeletal angle III malocclusion.
  
  
  METHODS
  A case-control study of 96 probands, 200 controls and their relatives was performed and the data were analyzed with genetic epidemiologic methods. SPSS11.5 software package was used for Chi-square test.
  
  
  RESULTS
  The prevalence rates of skeletal angle III malocclusion in the first-degree relatives and second-degree relatives in the proband group were 9.00% and 1.88%,respectively,which were higher than that in the first-degree relatives in the control group(0.96%). The heritability in the first-degree relatives was 0.74+/-0.092.The results of segregation analysis didn't suggest that skeletal angle III malocclusion followed a pattern of autosomal recessive inheritance.
  
  
  CONCLUSIONS
  Skeletal angle III malocclusion has characteristics of polygenetic disease. Genetic factor might play an important role in the pathogenesis of skeletal angle III malocclusion.
authors.affiliation: Department of Orthodontics and Research Center for Stomatology, Stomatological Hospital, Xi'an Jiaotong University, Xi'an, 710004, Shanxi Province, China. 98wangshuang@sohu.com
authors.forename: Shuang
authors.initials: S
authors.lastname: Wang
authors.forename: Pei-xun
authors.initials: PX
authors.lastname: Feng
authors.forename: Xiong
authors.initials: X
authors.lastname: Guo
authors.forename: Xiao-rong
authors.initials: XR
authors.lastname: Wang
mesh_terms: D016022:Case-Control Studies; D016009:Chi-Square Distribution; D006801:Humans; D008310:Malocclusion / Q000453:epidemiology / Q000235:genetics; D008313:Malocclusion, Angle Class III / Q000453:epidemiology* / Q000235:genetics*; D015995:Prevalence; D019655:Quantitative Trait, Heritable