An Automatic Algorithm for Repairing Dental Models Based on Contours

摘要

Dental model repair is a critical stage in the orthodontic treatment. The repaired teeth need to preserve the originalmorphological features, and the algorithm is required to be automatic for saving time and avoiding uncertainty caused byhuman handling. This paper presents an efficient and automatic algorithm to repair the tooth models' large holes. Ouralgorithm consists of three main steps: model's principal axis determination, model's contours processing (generation andrepair), and hole surface reconstruction & fairing. We propose a novel LRBC (Linear Regression on Boundaries'Centers) algorithm to determine the model's principal axis. After generating contours based on the principal axis, weadopt point-normal cubic B-spline curve interpolation to repair each broken contour line. At last, we reconstruct holes'point-sets by constrained Delaunay triangulation, and smooth the patches with a modified Laplacian operator.Experiments on different dental models demonstrate that our algorithm can not only achieve a result with a highmorphological similarity and a low error, but also satisfy the requirements of actual orthodontic applications.