1. A method for mounting at least two physical tooth models on a physical dental arch model, comprising: acquiring coordinates of a plurality of points on the surfaces of each of the two physical tooth models; digitally representing the surfaces of each of the two physical tooth models as a mesh of points in three dimensions using the acquired coordinates, wherein the meshes representing the surfaces of the two physical tooth models intersect at least at one point to form an overlapping portion; and calculating the depth of the overlapping portion between the two meshes to quantify the interference of the two physical tooth models.