title: [Hard and soft tissue changes following the treatment of Class II division 1 malocclusion using twin-block appliance].
abstract: OBJECTIVE
  To investigate the hard and soft tissue changes following the treatment of Class II division 1 malocclusion using Twin-block appliance.
  
  
  METHODS
  50 Class II division 1 malocclusion subjects whose handwrist radiographs were in FG-G stage were selected. One group (27 patients) was treated with Twin-block appliance, the other group (23 patients) was observed without treatment The acquired data of cephalometric of two groups were analyzed statistically with SPSS 11.0.
  
  
  RESULTS
  Soft tissue changes, Ls-E, Li-E, U1-Stms, Stms-Stmi, NsLs-FH, LsNsLi, LsNsPg', the angle of H decreased. Sn-Stms, Stmi-Me', Ns-Me', Sn-Me', NsLi-FH, NsPg'-FH, A'Ls-FH, B'Li-FH, LiB' Pg', CmSnLs, GSnPg', the angle of Z increased, there was statistically significant difference (P < 0.05). Hard tissue changes, SNB, L1-NB, IMPA increased, ANB, U1-SN, U1-NA, FMIA decreased, there was statistically significant difference (P < 0.05).
  
  
  CONCLUSIONS
  Sagittal relationship between upper- and lower-jaws is effectively improved after orthopedics with Twin-block appliance. Lower face height increases. Soft tissue profile tends to be straight-styled.
authors.affiliation: Dept. of Stomatology, The Bethune International Peace Hospital, Shijiazhuang 050082, China.
authors.forename: Li-Guo
authors.initials: LG
authors.lastname: Li
authors.forename: Yan-Ping
authors.initials: YP
authors.lastname: Zuo
authors.forename: Dong-Hui
authors.initials: DH
authors.lastname: Yuan
mesh_terms: D002508:Cephalometry; D005145:Face; D006801:Humans; D008310:Malocclusion; D008334:Mandible