title: Genetic polymorphisms underlying the skeletal Class III phenotype.
abstract: BACKGROUND
  Our goal was to verify the association between candidate polymorphisms and skeletal Class III malocclusion in a well-characterized homogeneous sample set.
  
  
  METHODS
  Thirty-five single-nucleotide polymorphisms were studied from 10 candidate loci in 54 Class III subjects and 120 controls. Skeletal Class III characteristics included ANB angle less than 0°, SNB angle greater than 83° (mandibular prognathism), SNA angle less than 79° (maxillary deficiency), Class III molar relationship, and negative overjet. Inclusion criteria for the controls were ANB angle between 0° and 4°, Class I molar relationship, and normal overjet. Chi-square and Fisher exact tests and principal component (PC) analysis were used to determine overrepresentation of marker alleles with alpha of 0.05. Odds ratios and 95% confidence intervals were calculated.
  
  
  RESULTS
  MYO1H (rs10850110 A<G) (P <0.01; odds ratio, 7.44 [4.02-13.77]) was associated with an increased risk for the mandibular prognathism phenotype. These results were confirmed by PC analysis, which showed 4 PCs representing the sample variations (PC1, 37.24%; PC2, 20.02%; PC3, 12.18%; and PC4, 11.40%), and PC1 was associated with MYO1H (P <0.001). We also found by PC analysis associations between MYO1H (P <0.001) and GHR (rs2973015 A>G) (P = 0.001) with PC2 and between FGF10 (rs593307 A<G) (P = 0.001) with PC4.
  
  
  CONCLUSIONS
  Polymorphism in MYO1H could be used as a marker for genetic susceptibility to Class III malocclusion with mandibular prognathism, and polymorphisms in GHR and FGF were associated with maxillomandibular discrepancies. This study may contribute to improved diagnosis and further research assessing possible differences in treatment responses based on genetic polymorphisms.
authors.affiliation: Department of Pediatric Dentistry and Orthodontics, School of Dentistry, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Christiane Vasconcellos
authors.initials: CV
authors.lastname: Cruz
authors.affiliation: Department of Orthodontics, Fluminense Federal University, Niterói, Rio de Janeiro, Brazil.
authors.forename: Claudia Trindade
authors.initials: CT
authors.lastname: Mattos
authors.affiliation: Department of Orthodontics, Fluminense Federal University, Nova Friburgo, Rio de Janeiro, Brazil.
authors.forename: José Calasans
authors.initials: JC
authors.lastname: Maia
authors.affiliation: National Institute of Metrology, Quality and Technology, Duque de Caxias, Rio de Janeiro, Brazil.
authors.forename: José Mauro
authors.initials: JM
authors.lastname: Granjeiro
authors.affiliation: Department of Oral Biology, School of Dental Medicine, University of Pittsburgh, Pittsburgh, Pa.
authors.forename: Maria Fernanda
authors.initials: MF
authors.lastname: Reis
authors.affiliation: Department of Orthodontics, Fluminense Federal University, Niterói, Rio de Janeiro, Brazil.
authors.forename: José Nelson
authors.initials: JN
authors.lastname: Mucha
authors.affiliation: Department of Orthodontics, Fluminense Federal University, Niterói, Rio de Janeiro, Brazil.
authors.forename: Beatriz
authors.initials: B
authors.lastname: Vilella
authors.affiliation: Department of Pediatric Dentistry and Orthodontics, School of Dentistry, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Antonio Carlos
authors.initials: AC
authors.lastname: Ruellas
authors.affiliation: Institute for Studies in Public Health, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Ronir Raggio
authors.initials: RR
authors.lastname: Luiz
authors.affiliation: Department of Pediatric Dentistry and Orthodontics, School of Dentistry, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Marcelo Castro
authors.initials: MC
authors.lastname: Costa
authors.affiliation: Department of Oral Biology, School of Dental Medicine, University of Pittsburgh, Pittsburgh, Pa. Electronic address: arv11@pitt.edu.
authors.forename: Alexandre Rezende
authors.initials: AR
authors.lastname: Vieira
mesh_terms: D002352:Carrier Proteins / Q000235:genetics / Q000502:physiology; D016022:Case-Control Studies; D005260:Female; D051526:Fibroblast Growth Factor 10 / Q000235:genetics / Q000502:physiology; D056726:Genetic Association Studies; D006801:Humans; D008297:Male; D008313:Malocclusion, Angle Class III / Q000235:genetics*; D024461:Myosin Type I / Q000235:genetics / Q000502:physiology; D020641:Polymorphism, Single Nucleotide / Q000235:genetics* / Q000502:physiology; D055815:Young Adult
chemical_list: D002352:Carrier Proteins; C496463:FGF10 protein, human; D051526:Fibroblast Growth Factor 10; C569966:myosin 1H, human; D024461:Myosin Type I; C051815:somatotropin-binding protein