title: [The three-dimensional nonlinear finite element analysis of force system of the "rocking-chair archwire"].
abstract: OBJECTIVE
  The purpose of this study was to qualitatively and quantitatively analyze the initial force system of "rocking-chair archwire" on every tooth.
  
  
  METHODS
  Three-dimensional finite element model of "rocking-chair archwire" was set up, and nonlinear method was used to analyze the force system.
  
  
  RESULTS
  The archwire exerted intruding force, labial force, lingual-root torque and mesial-labial moment on incisors; Extruding force, lingual-root torque and mesial-labial moment were applied on canines and premolars; The archwire also created intruding force, buccal force, buccal-root torque and mesial-labial moment on molars.
  
  
  CONCLUSIONS
  "rocking-chair archwire" produced a complicated force system. While intruding incisors, molars and extruding premolars. It has a tendency to induce tooth rotation and tipping.
authors.affiliation: Department of Orthodontics, Beijing Hospital for Stomatology, Capital University of Medical Sciences, Beijing 100050, China.
authors.forename: Li
authors.initials: L
authors.lastname: Chen
authors.forename: Ding
authors.initials: D
authors.lastname: Zhang
authors.forename: Min-kui
authors.initials: MK
authors.lastname: Fu
authors.forename: Shu-li
authors.initials: SL
authors.lastname: Sun
authors.forename: Ying
authors.initials: Y
authors.lastname: Liang
mesh_terms: D003799:Dental Stress Analysis; D020342:Finite Element Analysis; D006801:Humans; D008310:Malocclusion / Q000628:therapy*; D016382:Orthodontic Appliance Design; D009969:Orthodontic Wires; D009971:Orthodontics, Corrective / Q000379:methods*