1. Section of Preventive and Public Health Dentistry, Division of Oral Health Growth and Development, Faculty of Dental Science; Kyushu University; Fukuoka Japan
2. Department of Oral Diseases Research; National Center for Geriatrics and Gerontology; Obu Japan
3. Tokyo Metropolitan Institute of Gerontology; Tokyo Japan
4. Center for Comprehensive Care and Research on Memory Disorders; National Center for Geriatrics and Gerontology; Obu Japan
5. Center for Gerontology and Social Science; National Center for Geriatrics and Gerontology; Obu Japan