Numerical Study On Bone-Remodeling In Orthodontic

The research on tooth movement is a vital subject in orthodontic biomechanics. The most current researches mainly focused on constructing finite element model, analyzing stress or strain distribution in model, and then predicting orthodontic effects, however, few researches were done on the simulation of tooth movement process. On the other hand, research on bone remodeling now acquires considerable achievement, but there are no theories and equations derived directly for alveolar remodeling process. There are also few researches on tooth-movement simulation based upon bone remodeling theories. In this thesis, we developed an improved bone remodeling equation in which principal stress serve as stimulus variant. Then a simulation of the tooth movement process was realized by using FEM combining the improved bone remodeling equations. And following works have been finished in the thesis:1) Construct an improved bone remodeling equation in which principal stress serve as stimulus variant, which is different from other equations before. The improved equation can better satisfy the simulation for periodontal remodeling, satisfy the Wolff law and clinical observation. And it was proved that the convergence could be arrived when it was used to simulate the bone remodeling numerically in orthodontics.2) The optimal principal stress range was obtained by adopting the optimal orthodontic force, which aroused from the animal and clinical experiments on bodilytooth-movement force and subsequent displacement by Yinjin and Maltha.3) A procedure describing the relation between principal stress and tooth movement displacement was developed, then the corresponding codes were written using APDL language in ANSYS. Then the numerical simulation on tooth movement was made by utilizing element birth and death technology in FEM and the improved bone-remodeling equation. Results indicated that there are similar trends between the clinical observations and the numerical simulation on displacement during the process. And the results are also consistent with the experimental result performed by Yinjin and Maltha.