1. Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research College of Stomatology Xi'an Jiaotong University Xi'an 710004 P. R. China
2. The Key Laboratory of Biomedical Information Engineering of Ministry of Education School of Life Science and Technology Xi'an Jiaotong University Xi'an 710049 P. R. China
3. Bioinspired Engineering and Biomechanics Center (BEBC) Xi'an Jiaotong University Xi'an 710049 P. R. China
4. State Key Laboratory of Military Stomatology Department of General Dentistry and Emergency School of Stomatology Fourth Military Medical University Xi'an 710032 P. R. China
5. Department of Mechanical Engineering & Materials Science Washington University in St. Louis St. Louis MO 63130 USA
6. NSF Science and Technology Center for Engineering MechanoBiology Washington University in St. Louis St. Louis MO 63130 USA