title: An analytical approach to 3D orthodontic load systems.
abstract: OBJECTIVE
  To present and demonstrate a pseudo three-dimensional (3D) analytical approach for the characterization of orthodontic load (force and moment) systems.
  
  
  METHODS
  Previously measured 3D load systems were evaluated and compared using the traditional two-dimensional (2D) plane approach and the newly proposed vector method.
  
  
  RESULTS
  Although both methods demonstrated that the loop designs were not ideal for translatory space closure, they did so for entirely different and conflicting reasons.
  
  
  CONCLUSIONS
  The traditional 2D approach to the analysis of 3D load systems is flawed, but the established 2D orthodontic concepts can be substantially preserved and adapted to 3D with the use of a modified coordinate system that is aligned with the desired tooth translation.
authors.affiliation: a  Associate Professor, Department of Orthodontics and Oral Facial Genetics, Indiana University School of Dentistry, and Department of Mechanical Engineering, Purdue University School of Engineering and Technology, Indianapolis, Ind.
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Katona
authors.forename: Serkis C
authors.initials: SC
authors.lastname: Isikbay
authors.forename: Jie
authors.initials: J
authors.lastname: Chen
mesh_terms: D001696:Biomechanical Phenomena; D003481:Cuspid / Q000502:physiology; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D007180:Incisor / Q000502:physiology; D008954:Models, Biological; D016910:Orthodontic Brackets; D019516:Orthodontic Space Closure / Q000295:instrumentation; D009969:Orthodontic Wires; D013314:Stress, Mechanical
keywords: Biomechanics; Moment-to-force ratio; Orthodontic force systems; T-loop archwire; Three-dimensional