从3维牙颌模型中精确地分离出单颗牙齿是计算机辅助正畸治疗的重要步骤。由于牙齿有不同的形状并且不同个体之间有很大差异，其自动分离比较困难。为此，提出一种交互分割单颗牙齿的方法：首先，在牙颌模型上交互选定特征点，然后计算特征点间近似测地路径，待测地路径封闭后，利用区域生长方法从整个牙颌模型上精确分离出单颗牙齿。实验结果显示，该算法执行速度快，用户交互量少，且分割得到的牙齿边界线平滑，较好地满足口腔正畸的临床要求。

Separation individual tooth from three-dimensional dental model is an important step in computer aided orthodontics treatment. Because of different shapes of every tooth and huge difference among different people, it is difficult to partition individual tooth automatically. Therefore, this paper presents an interactive segmentation algorithm, whose process is firstly picking up feature points on triangle mesh of dental model interactively, then approximating the geodesic path between feature points and finally partitioning individual tooth from dental model by region grow algorithm once the geodesic path is closed. The experiment indicates that our algorithm runs fast and needs little interactive operation, while the border of the segmented tooth is smooth and meets the clinical requirement of orthodontics.