Computer aided invisible orthodontic treatment system

The invisible orthodontic surgery depends on pre-alignment of the misplaced teeth. Based on this requirement, a computer aided invisible orthodontic treatment system consisting of tooth shape modeling and virtual treatment planning is proposed. The input of the system is a digital dental model obtained by optical scanning and the output is the intermediate models ready for rapid prototyping manufacturing. The system consists of the following main steps: tooth segmentation, tooth restoration, tooth movement design, gum deformation, orthopedic scheme determination and virtual occlusion. The tooth model is segmented from the dental model using a two-step procedure. The segmenting region is firstly searched by exploiting the geometry features, and then the boundary is trimmed out by projecting the control curves. By specifying positional constraints using a network of control curves, the missing region between adjacent teeth is repaired based on differential coordinates. For gum deformation, the moving least-square interpolation scheme is employed to solve the problem on excessive consumption of memory space when solving the large-scale linear system. This system is the key step to manufacture invisible aligners. It also provides a visual environment for diagnosing the illness. Clinical trials on 50 cases show that our invisible orthodontic treatment system provides an efficient orthodontic treatment method.