The Finite Element Analysis Of The Biomechanics Characters In Distal Movement Of Mandible Canine With Tip-edge System

Tip-Edge technique is also called Differential Straight Wire technique. It has been invented on basis of traditional Straight Wire Appliance(SWA). It's characters include slender arch wire , slight force and differential tooch movement, etc. This system is good at the distal movement of canine and rectification of deep bite in extraction cases. So,it is very important to know the biomechanics characters of canine distal movement process, and it's differences with traditional Straight Wire Appliance. That will help us find more reasonable way to put force in canine in clinical practice, so that precise and rapid movement of canine can be gain.Objective:To reconstruct the three-dimensional finite element analysis models of the mandibular canine and periodontal supporting tissue with Tip-Edge system and SWA system. Then analysis the biomechanics characters of canine distal movement process with Tip-Edge system, and it's differences with traditional SWA system in order to be helpful for clinical practice.Methods:1. Firstly of all ,we used the three dimensional sensing system(3DSS) scan the standard model of mandibular canine, then we used the softs of Geomagic Studio10.0 and ANSYS10.0 to establish three-dimensional finite element analysis models of the right mandibular canine;2. To study the biomechanics characters of canine distal movement process with Tip-Edge system when the canine inclination is 0o,5o,10o,15o,20o and 25o.3. To study the different biomechanics characters of canine and it's periodontal tissue with Tip-Edge system and SWA system when the 50/150g forces are given to both of them respectively.Results:1. A 3D FE(Finite Element) model including mandibular canine, PDL around it's root, Tip-Edge bracket on it's crown, and lamina dura, cancellous and cortical bone was reconstructed successfully, which had 6 entity and 5 material attributes.2. In the six model with different canine inclination angle, the stress is localize in the same place. The value of stress is degrade with the inclination angle increase. Before the canine inclination angle increased to 10o,the value of stress is almost the same, but after that it decreased quickly. 3. The canine with Tip-Edge bracket had tiping movement, and the canine with SWA bracket had bodily movement. When we give forces we often used in clinical practice to these two system, we found that the value of stress of Tip-Edge system was only a little lower than the SWA system.Conclusion:1.The way to build FEM with RE techqunie is quick,accurate,and efficiency. The FEM we builded can satisfied the requirement of biomechanics research;2. Before the canine inclination angle increased to 10o,the value of stress is bigger than other models with bigger inclination angle. So, to ensure enough treatment cycle time will be very important in this phase;3. The canine with Tip-Edge bracket had tiping movement, and a light force can lead high value stress in the periodontal tissue, so this tiping movement can lead a efficient tooch movement. And a light force should be use in order to protect periodontal tissue...