title: Skelate changes induced by orthodontic in class II division 1 by CBCT: a long-term follow-up prospective study.
abstract: OBJECTIVE
  To identify and evaluate changes in the sagittal position of point B due to orthodontic treatment using CBCT.
  
  
  METHODS
  The subjects comprised 80 patients received fixed appliance. In this population, group 1 consisting of 40 patients with Class II division 2 malocclusion and group 2 consisting of 40 patients with minor crowding in the beginning of the treatment and required no or minimal maxillary anterior tooth movement. Treatment changes in incisor inclination, sagittal position of point B, SNB and movement of incisor root apex and incisal edge were calculated on pretreatment and post treatment on CBCT.
  
  
  RESULTS
  Assessment of local changes in point B revealed that the point had moved backward. No significant change was observed in the value of the sella-nasion-point B angle (SNB) in both the study and control groups. However, the changes of horizontal displacement after treatment in SNB between the two groups were found to be significant. There were no significant changes in the vertical and Z position of points B in both group.
  
  
  CONCLUSIONS
  The position of point B was affected by local bone remodeling during orthodontic treatment. These changes significantly affect the SNB angle.
authors.affiliation: Department of Orthodontics, School & Hospital of Stomatology, Wenzhou Medical University Wenzhou, Zhejiang, China.
authors.forename: Shuofei
authors.initials: S
authors.lastname: Zhang
authors.affiliation: Department of Orthodontics, School & Hospital of Stomatology, Wenzhou Medical University Wenzhou, Zhejiang, China.
authors.forename: Weiting
authors.initials: W
authors.lastname: Chen
authors.affiliation: Integrated Traditional Chinese and Western Medicine Hospital of Wenzhou Affiliated Hospital of Zhejiang Chinese Medicine University Wenzhou, Zhejiang, China.
authors.forename: Sheng
authors.initials: S
authors.lastname: Ding
authors.affiliation: Integrated Traditional Chinese and Western Medicine Hospital of Wenzhou Affiliated Hospital of Zhejiang Chinese Medicine University Wenzhou, Zhejiang, China.
authors.forename: Hongwei
authors.initials: H
authors.lastname: Han
authors.affiliation: Department of Orthodontics, School & Hospital of Stomatology, Wenzhou Medical University Wenzhou, Zhejiang, China.
authors.forename: Zhou
authors.initials: Z
authors.lastname: Yu
keywords: Class II division 2; incisor proclination; point B