Stress analysis of the dynamic process simulation of canine tipping movement during a therapy period

With combining bone remodeling with finite element analysis, the dynamic process of canine tipping movement during a therapy period is simulated and the stress distribution in each phase is obtained. A three-dimensional finite element model including tooth, periodontal ligament, pulp and alveolar bone is established according to a mandibular canine of an orthodontic patient. Through finite element analysis, the strain distribution of the model is obtained under the initial moment. The normal strain on the surface of the periodontal ligament is assumed as the mechanical stimulus proportional to the absorption rate of alveolar bone in each week. Then the second model based on the moved canine is constructed. With the decreased moment, the computed normal strain of the periodontal ligament surface is also used for the next phase of tooth tipping movement. In a therapy period, the relationship between the time and the degree in the numerical simulation is consistent with typical tooth movement. The stresse in the alveolar bone and periodontal ligament gradually decreases and the maximum stress appears at the tooth apex or the crest of alveolar bone. The dynamic process simulation of canine tipping movement is achieved. It will be helpful for the planning and forecast of the therapy.