A Comparative evaluation of stress distribution in bone and mini-implant during en-masse retraction of anterior teeth in maxilla using forces from anchorage units (mini-implants and molar hook) to both canine hook and arch wire hook. An FEM study

Abstract

The study aimed to compare and evaluate the stress that was distributed around mini-implant, molar hook and anterior dentition during its en-masse retraction from both canine hook and arch-wire hook. Four FEM models of maxilla were created to carry out en-masse retraction of the anterior teeth using forces from mini-implant and molar hook to both arch-wire hook and canine hook. The force of 200 grams was applied with Ni-Ti closed coil spring in all four models to carry out anterior teeth retraction. Stress distribution were then analyzed. The mini-implant group showed higher stresses on the implant when compared to the molar hook group. The molar hook groups showed more stress on the dentition than that of the mini-implant group. The models where the arch-wire hook used for retraction showed less stress values on the bone, teeth, dentition, PDL when compared with that of the canine hook.The arch-wire hook can be considered a better option than the canine hook. When forces were applied to the arch-wire hook lesser stresses were seen on bone, teeth, dentition, and PDL. The implant-supported group showed lesser stress values on teeth when compared with that of the molar hook group.