title: [Three-dimensional morphological analysis of corticotomy-assisted intrusion of premolars in Beagle dogs].
abstract: OBJECTIVE
  This study aims to identify the effects of corticotomy-assisted orthodontic premolar intrusion andevaluate the changes of root resorption and the alveolar bone.
  
  
  METHODS
  Both sides of the mandible of eight male Beagle dogswere randomly assigned into experimental and control groups. The third (P3) and fourth (P4) premolars were intruded withboth mini-screw implant anchorage (MIA) and corticotomy on the experimental side. By contrast, P3 and P4 were intrudedwith MIA alone on the control side. During pre-operation and after 2, 4, 8, and 12 weeks of orthodontic force applications,cone beam computed tomography was performed on every dog. The distance of tooth intrusion and root resorption of furcation, as well as the apex and height changes of the alveolar bone were measured and analyzed.
  
  
  RESULTS
  The intrusion distanceof premolars on the experimental side was greater than that on the control side (P < 0.05). The root of furcation and apex onboth sides occurred in root resorption, and the root resorption of the apex on the experimental side was lighter than that onthe control side after 12 weeks of force application (P < 0.05). The alveolar bone height decreased, and the height reductiondistance on the experimental side was greater than that on the control side after 8 and 12 weeks of force application (P < 0.05).
  
  
  CONCLUSIONS
  Corticotomy accelerates orthodontic molarintrusion and reduces root resorption.
authors.forename: Feng
authors.initials: F
authors.lastname: Yu
authors.forename: Deng
authors.initials: D
authors.lastname: Feng
authors.forename: Zhang
authors.initials: Z
authors.lastname: Yi
authors.forename: Zhu
authors.initials: Z
authors.lastname: Yaling
authors.forename: Zhang
authors.initials: Z
authors.lastname: Xiangfeng
authors.forename: Zhang
authors.initials: Z
authors.lastname: He
authors.forename: Wang
authors.initials: W
authors.lastname: Huaqiao
mesh_terms: D000818:Animals; D001641:Bicuspid / Q000033:anatomy & histology*; D001863:Bone Screws; D054893:Cone-Beam Computed Tomography; D004285:Dogs; D008297:Male; D008334:Mandible; D012391:Root Resorption; D014087:Tooth Movement Techniques; D014092:Tooth Root