The Finite Element Analysis Of Upper Dentition With Edgewise Appliance Orthodontia

With the rapid development of biomechanics and computer technology, three dimensional finite element method as effective means of studying orthodontics, has been widely used to study the stress distribution and displacement in dental organizations under orthodontic force. The establishment of 3-D finite element model with good geometric similarity and mechanical property, finite element analysis of dental stress and displacement can be theoretical guidance of improving the edgewise appliance in clinical treatment. The content reads as follows.The establishment of 3-D finite element model of teeth:Dicom files were inputted to the Mimics 8.1 software, and the teeth were selected and improved via appropriate gray threshold. Then the three-dimensional model of upper dentition was outputted. Following that, the model was preprocessed in general finite element analysis software ANSYS. After modeling alveolar bone, brackets and edgewise wire, the whole model was meshed and the material properties were defined.Orthodontic pressure was imposed vertically on the outboard surface of edgewise wire model. It effects the teeth through brackets. Through finite element analysis of the model, it can be found that there was a total displacement of teeth and stress concentration in the root region. When orthodontic force was loaded on both ends of wire, the distribution of stress and displacement was also analyzed. Furthermore, according to statistic, children's incisors orthodontic treatment accounts for a considerable proportion in orthodontic cases. In order to find out the best position for bracket in the incisors orthodontic treatment, the stress and displacement made by different height of brackets were also analyzed and compared in the paper. Eventually, the best height of brackets was determined.This paper establishes the 3-D finite element model which consists of the upper dentition, alveolar bone, brackets and edgewise wire. It also analyses the stress and displacement of the entire dentition and single teeth. The result effectively reflects the biomechanical properties in orthodontic treatment, which may provide a theoretical basis for dentists to improve orthodontic treatment programme.