1. Department of International and Community Oral Health Graduate School of Dentistry Tohoku University Sendai Japan
2. Department of Oral Health Promotion Graduate School of Medical and Dental Sciences Tokyo Medical and Dental University Tokyo Japan
3. Department of Social Preventive Medical Sciences Center for Preventive Medical Sciences Chiba University Chiba Japan
4. Department of Gerontological Evaluation Center for Gerontology and Social ScienceNational Center for Geriatrics and Gerontology Obu City, Aichi Japan