The accurate segmentation of the teeth from the triangle mesh is an important step in computer-aided orthodontic. Because teeth come in different shapes and their arrangements vary substantially from one individual to another, tooth segmentation is difficult. This paper proposes a new method to accurately segment the teeth interactively. Based on curvature values of the triangle mesh, feature points are connected to feature regions. After feature lines are extracted from regions, feature contour can be obtained with the help of user supplied information. Using feature contour, the tooth are segmented accurately and individually.