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.