Abstract: Objective To investigate the value of multislice spiral CT (MSCT) scanning and three-dimensional reconstruction in selecting optimal length and shape of mandible internal fixation material. Methods Three-dimensional reconstruction of the mandible was performed in 5 cases by MSCT scanning and the length of the mandible for operation was measured. Some isometric points were chosen on the mandibular curve and the distance from these points to the two ends of the curve was measured to depict the mandibular curve using a self-designed skeletal curve-depicting software. The optimal length and shape of the material for internal fixation was then determined. Results After removal of the soft tissues and other irrelevant bones from the reconstructed three-dimensional mandible with clear view from any directions, the length of the mandible was accurately measured with the software. The physiological curve of the mandible was generated after determination of the distances from the chosen points on the mandibular curve and to the two ends of the curve for precise determination of the length and shape of the material for internal fixation. Conclusion Three-dimensional mandible reconstruction with MSCT and measurement facilitates the determination of the optimal length and shape of the internal fixation material to enhance the attachment between the material and the bone surface and consequently the therapeutic effects.