title: [Morphological characteristics of upper alveolar bone around central incisor in Class II division 1 and division 2 malocclusion on cone-beam CT].
abstract: OBJECTIVE
  During orthodontic treatment, the incisors in patients with Class II division 1 and division 2 malocclusion showed different clinical features, which determine the different ways to move the teeth to the suitable position. This study analyzed the morphology of alveolar bone around upper central incisor with cone-beam CT (CBCT).
  
  
  METHODS
  The sample consisted of 20 normal malocclusion and 40 patients with Class II malocclusion （division 1 20 cases and division 2 20 cases）. CBCT images before orthodontic treatment were reconstructed by INVIVO 5.0 image processing software. Paired t test was used for statistical analysis with SPSS 19.0 software package.
  
  
  RESULTS
  At the upper central incisors, the alveolar thickness between normal malocclusion and Class II division 1 and division 2 malocclusion had significant difference except the palate thickness between normal malocclusion and Class II division 2 malocclusion (P<0.05).
  
  
  CONCLUSIONS
  Orthodontist should consider the relationship between the teeth position and alveolar bone shape comprehensively, choose the correct plan in order to avoid root desorption, alveolar bone loss, fenestration and other adverse reactions.
authors.affiliation: Department of Orthodontics, Stomatology Hospital of Nantong City. Nanjing 226001, Jiangsu Province, China. E-mail:179373411@qq.com.
authors.forename: Wen-qian
authors.initials: WQ
authors.lastname: Xia
authors.affiliation: Department of Orthodontics, Stomatology Hospital of Nantong City. Nanjing 226001, Jiangsu Province, China.
authors.forename: Yong-jia
authors.initials: YJ
authors.lastname: Gu
authors.affiliation: Department of Orthodontics, Stomatology Hospital of Nantong City. Nanjing 226001, Jiangsu Province, China.
authors.forename: Mei-qin
authors.initials: MQ
authors.lastname: Gao
mesh_terms: D016301:Alveolar Bone Loss; D054893:Cone-Beam Computed Tomography; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007180:Incisor; D008310:Malocclusion; D008311:Malocclusion, Angle Class I / Q000000981:diagnostic imaging*; D008312:Malocclusion, Angle Class II / Q000000981:diagnostic imaging*; D008334:Mandible; D008437:Maxilla; D014092:Tooth Root