title: [Imaging classification of maxillary impacted central incisors].
abstract: OBJECTIVE
  To investigate the classification of maxillary impacted central incisors through three-dimensional images.
  
  
  METHODS
  Based on the original Dicom data of the spiral computed tomography of 103 patients with maxillary impacted central incisors, the three-dimensional images of maxillary impacted central incisors were reconstructed by Mimics 10.0 software, and the characteristics were analyzed and a classification was proposed.
  
  
  RESULTS
  There were 106 teeth included in this study, 74 teeth were located labially, including 33 inverted impacted teeth, 28 horizontally impacted teeth, and 13 inclined teeth. 20 teeth were located in the palatal side, including 11 inclined teeth and 9 horizontally impacted teeth. 12 teeth were within the bone, which can be divided into three categories based on the position of the crown and in accordance with the vertical, far to near, and horizontal direction. Type I was labially impacted incisor, including 3 subdivisions: labially inclined impacted, labially horizontal impacted and labially inverted impacted. Type II was palatally impacted incisor, including 2 subdivisions: palatally inclined impacted and palatally horizontal impacted. Type III was vertically impacted incisor.
  
  
  CONCLUSIONS
  The maxillary impacted incisors can be divided into 3 categories based on three-dimensional directions, and subdivisions can be created in each group including labially (inclined, horizontal, inverted) impacted incisors, palatally (inclined, horizontal) impacted incisor and vertically impacted incisors.
authors.affiliation: Department of Stomatology, the First People's Hospital of Xiaoshan. Hangzhou, Zhejiang Province, China. wxsdentist@yahoo.cn
authors.forename: Xiang-shan
authors.initials: XS
authors.lastname: Wang
authors.forename: Rong-dang
authors.initials: RD
authors.lastname: Hu
mesh_terms: D001641:Bicuspid; D003481:Cuspid; D006801:Humans; D007180:Incisor; D008437:Maxilla; D009811:Odontometry; D019228:Tooth Crown; D014095:Tooth, Impacted