Multi-Body Contact Finite Element Analysis of Teeth and Orthodontic Devices

The purpose of this research was to study the contact between adjacent teeth and the biomechanical reactions of the teeth root, mandible, and periodontal membrane under orthodontic forces. First, the mandible and mandibular dentition were scanned by spiral computed tomography, and then reconstructed. The contact problem of the three dimensional multi-body between arc wire orthodontic device and mandible and mandibular dentition was analyzed under the method of the finite element parametric quadratic programming which is developed based on the parametric variational principle and the multi-substructure technique. The rule of the contact force between arc wire and bracket, the stress distribution in mandible, mandibular dentition and orthodontic device was concluded by the analysis of the contact between arc wire and bracket, together with the contact of adjacent teeth during orthodontic. The displacement trend of tooth under various loadings was also concluded. Furthermore, the effect of contact with adjacent teeth on different tooth displacement was also analyzed under various arc wires and loading conditions. The research provides theoretic foundation for orthodontic treatment.