Objective To evaluate the outcome of alveolar cleft bone grafting using dental 3D-CT, and identify the position of the bone bridge. Methods Eighteen unilateral complete alveolar cleft patients were chosen in this study and using dental 3D-CT to evaluate the position of the bone bridge after three month bone graft. The alveolar cleft was divided at several section, the bone bridge position were checked, and the position of graft bone bridge were calculated. Results In mesial and distal direction, there was no difference between mesial and distal bone bridge（P>0.05）. In labial and palatal direction, labial bone bridge was more than palatal bone bridge（P
