1. Department of Oral Pathobiological Science and Surgery, Tokyo Dental College, Chiyoda, Tokyo 101– 0061, Japan
2. Department of Dentistry and Oral Surgery, Tokyo Metropolitan Health and Hospitals Corporation, Tama-Hokubu Medical Center, Higashimurayama, Tokyo 189–8511, Japan
3. Department of Dentistry and Oral Surgery, National Hospital Organization, Tokyo Medical Center, Meguro, Tokyo 152– 8902, Japan
4. Department of Oral and Maxillofacial Surgery, Tokyo Dental College, Chiyoda, Tokyo 101–0061, Japan