The effect of en masse retraction performed with lingual orthodontic appliances which have different arch wire forms and power arm positions on incisor and canine teeth: A finite element analysis

In this study, the first premolars extracted upper jaw model with periodontal ligament, alveolar bone, teeth, and leveling phase of orthodontic treatment was obtained from the library of 'The Visible Human Project'. Customized lingual orthodontic brackets and en masse retraction mechanics were placed on this maxilla model with computer software. The slot design in the brackets is ribbonwise in the anterior, edgewise in the posterior and the slot sizes are 0.018"*0.025". Flat and mushroom-shaped 0.017"*0.025" stainless steel lingual arch wires are placed in the models. In arch wires, closed springs are applied to the miniscrews placed between the right and left first and second molar teeth from the power arms of equal length placed between the canine and lateral teeth in the first and second models, and in the mesial part of the canine tooth in the third and fourth models, so that the incisors move equally into the tooth extraction space by applying closed springs. magnitude of force was applied. Reverse engineering and three-dimensional CAD activities of the upper jaw model used in the study were carried out with ALTAIR Evolve software, while adapting solid models to the analysis environment and creating an optimized mesh were performed with ALTAIR Hypermesh software. Nastran-based ALTAIR Optistruct (ALTAIR, Troy, MI, USA) implicit solver was used to solve the created finite element models. The changes that occur as a result of the applied force were examined with the ALTAIR Hyperview software.