1. Department of Oral and Maxillofacial Radiology, Tokyo Dental College, Tokyo, Japan
2. Graduate School of Keio University, Yokohama, Japan
3. Mechanical Engineering Department, Nippon Institute of Technology, Miyashiro, Japan
4. Department of Mechanical Engineering, Keio University, Yokohama, Japan
5. Department of Anatomy, Tokyo Dental College, Tokyo, Japan