title: Class II malocclusion division 1: a new classification method by cephalometric analysis.
abstract: OBJECTIVE
  The purpose of this study was to analyse the craniofacial and dentofacial skeletal characteristics in untreated subjects with Class II, division 1 malocclusion by mandibular retrusion and to identify different types and their prevalence.
  
  
  METHODS
  In 152 subjects with Class II, division 1 malocclusion by mandibular retrusion, the differences were determined by lateral cephalograms analysis of variance and chi-square test, respectively. P<0.05 was considered significant. Seven types of mandibular retrusion were identified: three pure, dimensional, rotational and positional, and four mixed.
  
  
  RESULTS
  All patients showed significant inter-group differences with P between 0.005 and 0.001. The dimensional type was the most common (28.9%) and the rotational-positional type was the rarest (5.9%). The pure dimensional type had the shortest mandibular body; the pure rotational type had larger SN/GoMe and the lowest AOBO; the pure positional type presented the flattest cranial base, high AOBO. In the mixed types, dento-skeletal features changed depending on how the main types assorted.
  
  
  CONCLUSIONS
  Identifying the type of mandibular retrusion is important for differential diagnosis in clinical practice and research.
authors.affiliation: Department of Dentistry, Second University of Naples, Italy. letizia.perillo@unina2.it
authors.forename: L
authors.initials: L
authors.lastname: Perillo
authors.forename: G
authors.initials: G
authors.lastname: Padricelli
authors.forename: G
authors.initials: G
authors.lastname: Isola
authors.forename: F
authors.initials: F
authors.lastname: Femiano
authors.forename: P
authors.initials: P
authors.lastname: Chiodini
authors.forename: G
authors.initials: G
authors.lastname: Matarese
mesh_terms: D000293:Adolescent; D000704:Analysis of Variance; D002508:Cephalometry; D016009:Chi-Square Distribution; D002648:Child; D002675:Child, Preschool; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008297:Male; D008312:Malocclusion, Angle Class II / Q000145:classification*; D008334:Mandible; D063173:Retrognathia / Q000145:classification*