1. Dental Center for Regional Medical Survey Kyushu Dental University Kitakyushu Fukuoka Japan
2. Department of Preventive Dentistry, Faculty of Dental Medicine and Graduate School of Dental Medicine Hokkaido University Sapporo Hokkaido Japan
3. Tokyo Metropolitan Institute for Geriatrics and Gerontology Itabashi‐Ku Tokyo Japan
4. Division of Periodontology Kyushu Dental University Kitakyushu Fukuoka Japan
5. Division of Infections and Molecular Biology Kyushu Dental University Kitakyushu Fukuoka Japan