1. Department of Oral Health Care Education, Graduate School of Medical and Dental Sciences; Tokyo Medical and Dental University; Tokyo Japan
2. Department of Dental Hygiene, Faculty of Health Care Science; Chiba Prefectural University of Health Sciences; Chiba Japan
3. Human Care Research Team; Tokyo Metropolitan Institute of Gerontology; Tokyo Japan
4. Research Team for Promoting Independence of the Elderly; Tokyo Metropolitan Institute of Gerontology; Tokyo Japan
5. Department of Behavioral Dentistry, Graduate School of Medical and Dental Sciences; Tokyo Medical and Dental University; Tokyo Japan
6. Dentistry and Oral Surgery; Tokyo Metropolitan Geriatric Hospital; Tokyo Japan
7. Department of Oral Diseases Research; National Center for Geriatrics and Gerontology; Aichi Japan