1. Department of Special Needs Dentistry, Division of Hygiene and Oral Health Showa University School of Dentistry Tokyo Japan
2. Research Team for Promoting Independence of the Elderly Tokyo Metropolitan Institute of Gerontology Tokyo Japan
3. Department of Oral Diseases Research National Center for Geriatrics and Gerontology Aichi Japan
4. Section of Oral Health Education, Graduate School of Medical and Dental Science Tokyo Medical and Dental University Tokyo Japan