1. Department of Prosthodontics, Gerodontology and Oral Rehabilitation; Osaka University Graduate School of Dentistry; Tokyo Japan
2. Department of Clinical Thanatology and Geriatric Behavioral Science; Osaka University Graduate School of Human Sciences; Tokyo Japan
3. Tokyo Metropolitan Geriatric Hospital and Institute of Gerontology; Tokyo Japan
4. School of Allied Health Sciences; Osaka University Graduate School of Medicine; Osaka Japan
5. School of Medicine; Keio University; Tokyo Japan