Oral Cavity Closed Jaw CT Images Segmentation For 3D Reconstruction And Mini-implant Stress Analysis

In the field of orthodontic treatment, orthodontic doctors always rely on their own clinical experience when making orthodontic plan for patients. That is a kind of “trial and error” treatment. With the development of computer technology, computer aided treatment provides a great help and convenience for doctors-patients communication and orthodontic treatment formulation. The premise of the computer aided treatment is the 3D reconstruction for the teeth. The 3D reconstruction of teeth has two purposes: one propose is as a 3D visualization of teeth for orthodontic doctors to facilitate observation, another one is to process the biomechanical simulation for orthodontic doctors to seek theoretical basis for clinical treatment. There are some researches in oral CT images segmentation field, but the researches about the oral closed jaw CT images is little. In this paper, we made a solution plan for the closed jaw CT images segmentation and 3D reconstruction. In addition, we also established TPBC(Teeth-PDL-Bone-Complex) solid model and processed the biomechanical simulation work.In view of the mission of oral closed jaw CT images segmentation and reconstruction, this paper has established a special solution. The details are as follows:All the CT images are segmented in two-dimensional space by using hybrid level set method. The hybrid level set method functions contain a global grayscale energy function, a local gray energy function, a boundary detection function and a shape prior function. These functions are to ensure the accuracy of image segmentation.After the segmentation of all the CT images in the 2D space, all the segmented images are put in the 3D space and are reconstructed 3D mesh models by using Marching Cube algorithm. We studied and analyzed the data structure of triangular mesh model and simplified the data structure of the models to establish the topological relationship data of teeth triangular mesh model. T his job is for the follow up mission.The mission to solve in the solution plan is the segmentation of the teeth triangular mesh model. Firstly, the surface Gaussian curvature and the average geodesic distance of the teeth models are calculated. A height segmentation function was established by the information fusion of the Gaussian curvature information and the average geodesic distance information. This height function is to help segmenting the teeth triangular mesh models. Next, the teeth triangular mesh models are segmented by using the height segmentation and the fast watershed marching algorithm. At last, a hole filling algorithm was used to fill the holes in the segmented mesh models.The TPBC solid model were established by using revere engineering technology. And the mini-implant stress analysis research is established.