1. Second Department of Oral Surgery, Faculty of Dentistry, Tokyo Medical and Dental University, 5-45, 1-Chome, Yushima, Bunkyo-ku, Tokyo 113, Japan
2. Department of Biochemistiy, Faculty of Dentistry, Tokyo Medical and Dental University, 5-45, 1-Chome, Yushima, Bunkyo-ku, Tokyo 113, Japan