1. Department of Periodontology, School of Dentistry Kyung Hee University Seoul South Korea
2. Department of Humanities in Dentistry & Research Institute of Oral Science Gangneung‐Wonju National University Gangneung South Korea
3. Private Clinic Gwangmyeong‐si South Korea
4. Private Clinic Suwon‐si South Korea
5. Department of Prosthodontics, School of Dentistry Dankook University Cheonan South Korea
6. Public Health Department Seoul Dental Hospital for the Disabled Seoul South Korea
7. Private Clinic Seoul South Korea
8. Private Clinic Goyang‐si South Korea
9. Department of Oral Medicine and Oral Diagnosis, School of Dentistry and Dental Research Institute Seoul National University Seoul South Korea
10. Institute of Aging Seoul National University Seoul South Korea
11. The Korean Academy of Geriatric Dentistry (KAGD) Uiwang‐si South Korea