title: Evaluating the effects of consolidation on intrusion and retraction using temporary anchorage devices-a FEM study.
abstract: BACKGROUND
  Extraction of premolars and retracting the anterior teeth using mini-implants and anterior retraction hooks became advent now a day. In such treatments, consolidation of arches is not done in regular practice. So, the present study is concentrated on effects of consolidation in two implant and three implant combinations of retraction and intrusion.
  
  
  METHODS
  A three-dimensional FEM model of maxillary teeth and periodontal ligament housed in the alveolar bone with the first premolars extracted is generated with appropriate number of elements and nodes. The models were broadly divided into two groups according to the no. of implants. Mini-implants were placed bilaterally between the second premolar and molar at varying heights (7, 10, 13 mm) in group I, and along with bilateral implants, an additional mid-implant is placed between the central incisors as group II. Brackets with 0.022 slot were placed on the teeth, 19 × 25 SS wire is placed in the brackets, an anterior retraction hook was placed at 9 mm height, and analysis was done to evaluate the stresses and displacement patterns in consolidation and non-consolidation models.
  
  
  RESULTS
  The results showed that consolidation of the anterior teeth during intrusion and retraction shows various advantages such as less stresses on the bone, PDL, implant, teeth, and no labial flaring of the anterior teeth and three implant system, i.e., two bilateral implant at 10 mm and a mid-implant at 12 mm between the centrals has shown to be better than other models as bodily movement is observed.
  
  
  CONCLUSIONS
  Consolidation is better than non consolidation during enmasse retraction and intrusion.
authors.affiliation: St. Joseph Dental College, Eluru, Andhra Pradesh, India. m.ortho16888@gmail.com.
authors.forename: Monica
authors.initials: M
authors.lastname: Namburi
authors.affiliation: St. Joseph Dental College, Eluru, Andhra Pradesh, India.
authors.forename: Sleevaraju
authors.initials: S
authors.lastname: Nagothu
authors.affiliation: St. Joseph Dental College, Eluru, Andhra Pradesh, India.
authors.forename: Chetan S
authors.initials: CS
authors.lastname: Kumar
authors.affiliation: St. Joseph Dental College, Eluru, Andhra Pradesh, India.
authors.forename: N
authors.initials: N
authors.lastname: Chakrapani
authors.affiliation: St. Joseph Dental College, Eluru, Andhra Pradesh, India.
authors.forename: C H
authors.initials: CH
authors.lastname: Hanumantharao
authors.affiliation: St. Joseph Dental College, Eluru, Andhra Pradesh, India.
authors.forename: Supradeep K
authors.initials: SK
authors.lastname: Kumar
mesh_terms: D003757:Dental Implantation / Q000379:methods; D015921:Dental Implants; D020342:Finite Element Analysis; D006801:Humans; D007180:Incisor; D003765:Models, Dental; D052280:Orthodontic Anchorage Procedures / Q000295:instrumentation* / Q000379:methods; D014087:Tooth Movement Techniques / Q000295:instrumentation* / Q000379:methods
chemical_list: D015921:Dental Implants
keywords: Bilateral implants; Consolidation; FEM; Initial displacements; Intrusion; Mini-screws; PDL; Retraction; Stress distribution; Three implants