title: [Root shape changes of impacted upper central incisor before and after orthodontic traction].
abstract: OBJECTIVE
  Changes of root shape of impacted upper central incisor before and after orthodontic traction were observed with dental cone-beam CT(CBCT), the timing for traction of impacted upper central incisor was investigated.
  
  
  METHODS
  Ten impacted maxillary central incisors were diagnosed via panoramic radiograph. CBCT images were taken preoperatively for accurate localization. Following combined treatment of dental surgery and orthodontic traction, ten impacted maxillary central incisors were guided out and aligned well. Final treatment results and the root development status were evaluated via CBCT.
  
  
  RESULTS
  Ten impacted maxillary central incisors were tracted to normal position. CBCT images before and after treatment showed that the root of impacted incisors with completed root apex had no change in shape, while the root of impacted incisors with uncompleted root apex developed continually with obviously improved shape and length.
  
  
  CONCLUSIONS
  Optimistic results can be achieved if the traction of impacted upper central incisor is carried out before root development completed.
authors.affiliation: Shisizhen Dental Clinic,Tongji University. Shanghai 200032, China. E-mail:drdenty@sohu.com.
authors.forename: Hong-wei
authors.initials: HW
authors.lastname: Dong
authors.affiliation: Research Institute of Pediatric Dentistry, Tongji University. Shanghai 200032, China.
authors.forename: Shi-ting
authors.initials: ST
authors.lastname: Xu
authors.affiliation: Shisizhen Dental Clinic,Tongji University. Shanghai 200032, China.
authors.forename: Yin-jun
authors.initials: YJ
authors.lastname: Yu
authors.affiliation: Research Institute of Pediatric Dentistry, Tongji University. Shanghai 200032, China.
authors.forename: Qin
authors.initials: Q
authors.lastname: Liang
mesh_terms: D054893:Cone-Beam Computed Tomography; D006801:Humans; D007180:Incisor; D008437:Maxilla; D011862:Radiography, Panoramic; D014092:Tooth Root; D014095:Tooth, Impacted / Q000628:therapy*; D014143:Traction