1. The Departments of Oral Anatomy, Department of Orthodontics, School of Dentistry, Showa University, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo 142, Japan
2. The Departments of Oral Anatomy
3. Department of Orthodontics, School of Dentistry, Showa University, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo 142, Japan