title: Different manifestations of Class II Division 2 incisor retroclination: a morphologic study.
abstract: BACKGROUND
  The aims of this study were to investigate whether there is a different transverse morphologic pattern of dental arches among patients with different manifestations of Class II Division 2 incisor retroclination and to evaluate to what extent the pattern of smaller-than-average teeth in Class II Division 2 malocclusion is common to all groups studied. This information might clarify whether different Class II Division 2 phenotypes represent a single etiology or multiple etiologies.
  
  
  METHODS
  The sample comprised 108 subjects with Class II Division 2 malocclusions, divided into 2 groups according to the type of incisor retroclination: group I included 43 Class II Division 2 subjects with retroclination exclusively of the maxillary central incisors, and group II included 65 Class II Division 2 subjects with retroclination of the 4 maxillary incisors. Maxillary and mandibular intercanine and intermolar widths as well as mesiodistal crown dimensions of the 4 maxillary and mandibular incisors were determined from the patients' initial study models. Mean values of all variables were compared between the 2 groups by sex with analysis of variance.
  
  
  RESULTS
  From the comparison between these 2 groups, no statistically significant differences were found for all transverse measurements (P >0.05). For all mesiodistal measurements analyzed, statistically significant differences between the groups were only found for the mean value of both maxillary lateral incisors' mesiodistal dimensions in both sexes (P <0.05).
  
  
  CONCLUSIONS
  It is not possible to attribute a characteristic pattern of dental arch-width and incisor mesiodistal dimensions to the different manifestations of incisor retroclination in Class II Division 2 malocclusion.
authors: Department of Orthodontics, Egas Moniz High Institute for Health Science, Lisbon, Portugal. pmarianop@sapo.pt
authors: Pedro
authors: P
authors: Mariano Pereira
authors: Afonso
authors: A
authors: Pinhão Ferreira
authors: Purificação
authors: P
authors: Tavares
authors: Ana Cristina
authors: AC
authors: Braga
mesh_terms: D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D002508:Cephalometry; D002648:Child; D003724:Dental Arch / Q000473:pathology; D005260:Female; D006801:Humans; D007180:Incisor / Q000473:pathology; D008297:Male; D008312:Malocclusion, Angle Class II / Q000209:etiology / Q000473:pathology*; D008437:Maxilla; D008875:Middle Aged; D003765:Models, Dental; D009811:Odontometry; D011336:Probability; D012189:Retrospective Studies; D019228:Tooth Crown / Q000033:anatomy & histology; D055815:Young Adult