Analysis of tooth movement in typodont using three-dimensional reverse engineering technology.

PURPOSE: This study aims to determine the measured accurate value of space movement distance of tooth in the process of orthodontic treatment, thereby contributing to the selection of clinical appliance treatment. METHODS: We obtained the point cloud data of all stages model by the 3D scanning equipment. Through the coordinate matching for each tested and the original model, we obtained the color difference maps (CDM), which represent the relative movement distance between measured and original model, rather than 3D absolute movement distance. Then we presented (1) a new algorithm based on the Iterative Closet Point matching algorithm and (2) a traditional method based on mean measurements, which obtained the 3D distance value of the tooth model. RESULTS: Firstly we obtained the movement style of the tooth model in the occlusal plane, then proposed 2 methods for the distance measurement of the tooth model based on the CDM; these methods can find the corresponding detection point, then obtained 3D space distance value for the tooth model. Through this value, we can calculate the situation of the dental force. The experiment result shows the feasibility of this algorithm.