1. Department of Oral Diseases Research; National Center for Geriatrics and Gerontology; Aichi Japan
2. Department of Oral Health Education, Graduate School of Medical and Dental Sciences; Tokyo Medical and Dental University; Tokyo Japan
3. Research Team for Promoting Independence of the Elderly; Tokyo Metropolitan Institute of Gerontology; Tokyo Japan
4. Department of Oral Medicine and Oral and Maxillofacial Surgery; Tokyo Dental College; Chiba Japan
5. Department of Geriatric Dentistry; Tsurumi University School of Dental Medicine; Kanagawa Japan