title: Analysis of maxillary arch force/couple systems for a simulated high canine malocclusion: Part 2. Elastic ligation.
abstract: OBJECTIVE
  To better understand the mechanics of bracket/archwire interaction through analysis of force and couple distribution along the maxillary arch using elastic ligation and to compare these results with passive ligation.
  
  
  METHODS
  An orthodontic simulator was used to study a high canine malocclusion. Force and couple distributions produced by elastic ligation and round wire were measured. Forces and couples were referenced to the center of resistance of each tooth. Tests were repeated for 12 bracket sets with 12 wires per set. Data were compared with those derived from similar tests for passive ligation.
  
  
  RESULTS
  Propagation of the force/couple systems around the arch using elastic ligation was extensive. Elastic ligation produced significantly more resistance to sliding, contributing to higher forces and couples at the center of resistance than were observed for passive ligation.
  
  
  CONCLUSIONS
  The results of this study suggest some potential mechanical advantages of passive over elastic ligation. In particular, limited propagation around the arch in passive ligation reduces the occurrence of unwanted force/couple systems compared with elastic ligation. These advantages may not transfer to a clinical setting because of the conditions of the tests; additional testing would be required to determine whether these advantages can be generalized.
authors.affiliation: Department of Dentistry, University of Alberta, Edmonton, Canada.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Fok
authors.forename: Roger W
authors.initials: RW
authors.lastname: Toogood
authors.forename: Hisham
authors.initials: H
authors.lastname: Badawi
authors.forename: Jason P
authors.initials: JP
authors.lastname: Carey
authors.forename: Paul W
authors.initials: PW
authors.lastname: Major
mesh_terms: D003198:Computer Simulation; D003300:Copper; D003481:Cuspid / Q000473:pathology*; D003722:Dental Alloys; D003724:Dental Arch / Q000503:physiopathology*; D003799:Dental Stress Analysis; D020724:Elastomers; D017276:Friction; D006801:Humans; D008310:Malocclusion / Q000503:physiopathology; D008437:Maxilla / Q000503:physiopathology; D015999:Multivariate Analysis; D009532:Nickel; D016382:Orthodontic Appliance Design; D016910:Orthodontic Brackets; D009969:Orthodontic Wires; D013314:Stress, Mechanical; D014025:Titanium
chemical_list: D003722:Dental Alloys; D020724:Elastomers; C040654:titanium nickelide; D003300:Copper; D009532:Nickel; D014025:Titanium