title: [A study on the combination of Nance arch and TPA in the use of straight-wire arch orthodontic treatment].
abstract: OBJECTIVE
  To evaluate the effect of combination of Nance and TPA on the use of MBT appliance to treat Class II division I malocclusion.
  
  
  METHODS
  Nineteen cases of Class II division I malocclusion, aged from 12 to 16 years, underwent Nance arch and TPA in the use of MBT appliance to reinforce molar anchorage. Cephalometric analysis and model measurements were conducted and compared before and after treatment using SAS8.0 software package.
  
  
  RESULTS
  The average forward movement of the first maxillary molar was (1.97 ± 0.696)mm, but still less than 1/3 of the extraction space.U1-SN reduced 10.97° ± 3.81°.There was no significant difference in GoGn-Sn angle,ALFH /AFH and posterior dental arch width(P>0.05).The soft tissue profile (Ls-E,Ls-Snpg,Cm-Sn-Ls) was improved remarkably (P<0.01).
  
  
  CONCLUSIONS
  The combination of Nance and TPA might be effective and simple anchorage in three dimensions.
authors.affiliation: Department of Orthodontics, Jingan Dental Clinic, Shanghai 200040, China. gys.ttdc@yahoo.com.cn
authors.forename: Shuang
authors.initials: S
authors.lastname: Yuan
authors.forename: Li-hong
authors.initials: LH
authors.lastname: Tang
authors.forename: Tian-hao
authors.initials: TH
authors.lastname: Li
authors.forename: Si-en
authors.initials: SE
authors.lastname: Weng
mesh_terms: D000293:Adolescent; D002508:Cephalometry; D003729:Dental Care; D006801:Humans; D008310:Malocclusion; D008312:Malocclusion, Angle Class II; D008963:Molar; D009969:Orthodontic Wires