A New Perspective in Rotation Correction; 3D Analysis During FEM

Introduction: The main goal of this study was to assess the vertical reaction of a lower right canine after being derotated by a couple of forces in a finite element setup. Method and material: Eight 3D models of canine with different root forms and length were designed, including: ellipsoid and triangular in occlusal aspect (cross-section), U-shaped and conical root forms from buccal aspect and then all of the 4 roots forms were designed in two length including long and short. A couple of two 0.25 N forces were applied in lingual side, and the amount of vertical displacement was measured. Result: The highest extrusion was obtained in the mesial of the short triangular root (0.000045981 mm), and the least extrusion also occurred in the mesial of the long ellipsoid root (0.000001014 mm). The highest intrusion occurred in the distal of the short conical (-0.00003843 mm), and the lowest intrusion occurred in the distal of the long ellipsoid root (-0.00000015641 mm). In the short ellipsoid root and the short U-shaped root, intrusion was observed on both the mesial and distal sides. Also, unlike other root shapes, the tooth with long U-shaped root extruded distally and intruded mesially. Conclusion: Different vertical displacements occur according to different root shapes and length after being derotated by a couple of forces.