1. Department of Dentistry and Oral Surgery, National Hospital Organization Kanazawa Medical Center, Kanazawa, Japan
2. Department of Dentistry and Oral Surgery, National Hospital Organization Higashi-Ohmi General Medical Center, Higashi-Ohmi, Japan
3. Oral and Maxillo-Facial Surgery, National Hospital Organization Takasaki General Medical Center, Takasaki, Japan
4. Department of Dentistry, Oral and Maxillofacial Surgery, National Hospital Organization Kyushu Medical Center, Fukuoka, Japan
5. Department of Dentistry and Oral Surgery, National Hospital Organization Miyakonojo Medical Center, Miyakonojo, Japan
6. Department of Dentistry and Oral Surgery, National Hospital Organization Tochigi Medical Center, Utsunomiya, Japan
7. Department of Dentistry and Oral Surgery, National Hospital Organization Yonago Medical Center, Yonago, Japan
8. Department of Dentistry and Oral Surgery, National Hospital Organization Nagoya Medical Center, Nagoya, Japan
9. Department of Dentistry, National Hospital Organization Okayama Medical Center, Okayama, Japan
10. Department of Dentistry, National Hospital Organization Tokyo Hospital, Kiyose, Japan
11. Department of Dentistry and Oral Surgery, National Hospital Organization Kure Medical Canter/Chugoku Cancer Center, Kure, Japan
12. Nishizawa Dental Clinic, Ueda, Japan
13. Department of Dentistry and Oral Surgery, National Hospital Organization Mie Chuo Medical Center, Tsu, Japan
14. Department of Dentistry and Oral Surgery, National Hospital Organization Minami Wakayama Medical Center, Tanabe, Japan
15. Department of Oral and Maxillofacial Surgery, National Hospital Organization Yokohama Medical Center, Yokohama, Japan
16. Department of Dentistry and Oral Surgery, National Hospital Organization Higashinagoya National Hospital, Nagoya, Japan
17. Department of Dentistry, National Hospital Organization Chiba-East Hospital, Chiba, Japan
18. Department of Dentistry, National Hospital Organization Fukuyama Medical Center, Fukuyama, Japan
19. Department of Oral Surgery, National Hospital Organization Tokyo Medical Center, Meguro, Japan
20. Department of Oral and Maxilla-Facial Surgery, National Hospital Organization Osaka National Hospital, Osaka, Japan
21. Department of Dentistry and Oral Surgery, National Hospital Organization Kumamoto Medical Center, Kumamoto, Japan
22. Department of Dentistry and Oral Surgery, Sendai Aoba Clinic, Sendai, Japan
23. Department of Dentistry, National Hospital Organization Utsunomiya Hospital, Utsunomiya, Japan
24. Department of Dentistry, National Hospital Organization Higashihiroshima Medical Center, Higashihiroshima, Japan
25. Department of Bacteriology I, National Institute of Infectious Diseases, Shinjuku, Japan
26. Department of Dentomaxillofacial Diagnosis and Treatment, Division of Oral and Maxillofacial Surgery, Graduate School of Kanagawa Dental University, Yokosuka, Japan