title: Factors controlling anterior torque during C-implant-dependent en-masse retraction without posterior appliances.
abstract: BACKGROUND
  Our objective was to evaluate the factors that affect effective torque control during en-masse incisor and canine retraction when using partially osseointegrated C-implants (Cimplant, Seoul, Korea) as the exclusive source of anchorage without posterior bonded or banded appliances.
  
  
  METHODS
  Base models were constructed from a dental study model. No brackets or bands were placed on the maxillary posterior dentition during retraction. The working archwire was modeled by using a 3-dimensional beam element (ANSYS beam 4, Swanson Analysis System, Canonsburg, Pa) with a cross section of 0.016 × 0.022-in stainless steel. Different heights of anterior retraction hooks and different degrees of gable bends were applied to the working utility archwire that was placed into the 0.8-mm diameter hole of the C-implant to generate anterior torque on the anterior segment of the teeth. The amount of tooth displacement after finite element analysis was exaggerated 70 times and compared with tooth-axis graphs of the central and lateral incisors and the canine.
  
  
  RESULTS
  The height of the anterior retraction hook and the degree of the gable bend had a combined effect on the labial crown torque applied to the incisors during en-masse retraction. By using 30° gable bends and the longest hook, lingual root movement of the 6 anterior teeth occurred. By using 20° gable bends, the 6 anterior teeth showed a translation tendency during retraction.
  
  
  CONCLUSIONS
  Three-dimensional en-masse retraction of the 6 anterior teeth can be accomplished by using partially osseointegrated C-implants as the only source of anchorage, gable bends, and a long retraction hook (biocreative therapy type I technique).
authors: Associate professor, Division of Orthodontics, Department of Dentistry, Catholic University of Korea, Seoul, Korea.
authors: Sung-Seo
authors: SS
authors: Mo
authors: Seong-Hun
authors: SH
authors: Kim
authors: Sang-Jin
authors: SJ
authors: Sung
authors: Kyu-Rhim
authors: KR
authors: Chung
authors: Youn-Sic
authors: YS
authors: Chun
authors: Yoon-Ah
authors: YA
authors: Kook
authors: Gerald
authors: G
authors: Nelson
mesh_terms: D000328:Adult; D003198:Computer Simulation; D003481:Cuspid; D015921:Dental Implants; D003799:Dental Stress Analysis / Q000295:instrumentation / Q000379:methods; D020342:Finite Element Analysis; D006801:Humans; D007180:Incisor; D008437:Maxilla; D008904:Miniaturization; D003765:Models, Dental; D052280:Orthodontic Anchorage Procedures / Q000295:instrumentation*; D016382:Orthodontic Appliance Design; D009971:Orthodontics, Corrective / Q000379:methods*; D016348:Osseointegration; D057887:Overbite / Q000628:therapy*; D010513:Periodontal Ligament; D019415:Torque
chemical_list: D015921:Dental Implants