Evaluation of Optimal Implant Positions and Height of Retraction Hook for Intrusive and Bodily Movement of Anterior Teeth in Sliding Mechanics: A FEM Study

Abstract

Introduction: The design of an appliance for retraction of six anterior teeth using orthodontic mini-implant (OMI) anchorage and sliding mechanics must take into account the position and height of the mini-implant and the height of the anterior retraction hook, we used finite element analysis to examine effective en masse retraction with orthodontic mini-implant anchorage and sought to identify a better combination of the above factors. Materials and methods: Base models were constructed from a measurements given in the Wheeler’s dental anatomy book. The center of resistance for the 6 anterior teeth in the base model was calculated. The working archwires were assumed to be 0.019 × 0.025 in stainless steel. The amount of tooth displacement after finite element analysis was measured. Results and conclusions: In low OMI (6 mm) anteriors showed tipping movement. Mid implant condition (8 mm) showed more of bodily movement during retraction as the force passes near or through the CRs of all the six anterior teeth. In high OMI (10 mm) and 0 mm ARH condition, all the six anterior teeth showed intrusion with retraction.