Simulation On The Maxillary Canine Movement Under Orthodontic Force

Orthodontic treatment for dental malocclusion is to apply forces to dental arch by use of appliance, and the malocclusion treatment can be obtained by ways of correcting the inter-maxillary occlusal relations and reconstruction of occlusal biomechanical equilibrium in general. It is important to analyze the stress distribution in tooth, periodontal ligament and alveolar bone under orthodontic forces. There are many reports on periodontal tissue stress analysis, but at present stress analysis for tooth movement is confined to instant loading status. And the stress distributions are usually used to give an assessment of the clinical orthodontic forces. In fact, this is the static analysis and it is far from the fact orthodontic therapy. Clinical therapy is a continuous and dynamic process, and orthodontic force is continuous and changed with the tooth position.The stress distribution in periodontal tissue plays a very important role in determining tooth movement. And this is also useful for understanding the reconstruction of periodontal membrane and alveolar bone or tooth root absorb. The results can be used as instructions for the clinical usefulness of the theories of optimal force and differential force. A three-dimensional canine model including alveolar bone, periodontal membrane and pulp were obtained to analyze the stress distribution under differential orthodontic force.The stress values in different stages in a long-time movement of canine retraction were calculated under different kinds of orthodontic tooth movement: distal tipping movement and distal translation then the results were contrasted withpractical curve. A particular program and the stress distribution were used to calculate the movement distance and find the new position of canine during a week. Then the model was rebuilt at the tooth new position with force lost. The model was used as initial state then above process was done again .At last a curve of canine movement in a therapy periods was obtained, and this can be used as instructions for orthodontic treatment.