1. Objective To investigate root canal curvatures of human maxillary first premolars in buccolingual directions.

2. Results: The geometric feature parameters of 28 artificial teeth in their own coordinates were obtained, including the mesiodistal and buccolingual dimension, the height and inclination of cusp.

3. Results MPR was able to demonstrate the relative bone intensity around the implanted tooth and exactly determine the distance of impacted tooth with the buccolingual bone wall or adjacent teeth.

4. MB2 root canals were found by the rate of 35% and were 91% curved in mesiodistal direction and 83% in buccolingual direction.

5. The segments had the biomechanical properties of osteoporosis. 100 N and 30 N loads were applied along the implant axial(AX) and buccolingual(BL) directions respectively.