title: [Clinical study of Twin-wires on anchorage on canine retraction].
abstract: OBJECTIVE
  The purpose of the study was to evaluate the effects of anchorage by Twin-wires on canine retraction.
  
  
  METHODS
  A sample of 15 patients with severe anterior crowding was selected (6 males, 9 females, age average: 13.7 years). All patients underwent removal of the four first premolars during orthodontic treatment. Retraction of canine was achieved by using 0.018 stainless steel wire and NiTi wire. Anchorage reinforcement as a result of this movement was evaluated. The length and width of the dental arch models were measured. Self-control t test was used for data analysis.
  
  
  RESULTS
  The length and width of the dental arches, the canine and molar relationships remained unchanged after orthodontic treatment.
  
  
  CONCLUSIONS
  Application of Twin-wires leads to canine retraction and sufficient anchorage consolidation.
authors.affiliation: Department of Stomatology, Shanghai Putuo Central Hospital, Shanghai, China. drwanggh@126.com
authors.forename: Guo-hua
authors.initials: GH
authors.lastname: Wang
authors.forename: Ping
authors.initials: P
authors.lastname: Liu
authors.forename: Yang-ming
authors.initials: YM
authors.lastname: Ou
mesh_terms: D000293:Adolescent; D001641:Bicuspid / Q000601:surgery; D003481:Cuspid; D003724:Dental Arch; D003764:Dental Materials; D005260:Female; D006801:Humans; D008297:Male; D008310:Malocclusion / Q000628:therapy*; D003765:Models, Dental; D009532:Nickel; D052280:Orthodontic Anchorage Procedures / Q000295:instrumentation*; D009969:Orthodontic Wires; D013193:Stainless Steel; D014025:Titanium; D014087:Tooth Movement Techniques / Q000295:instrumentation*
chemical_list: D003764:Dental Materials; C040654:titanium nickelide; D013193:Stainless Steel; D009532:Nickel; D014025:Titanium