1. Department of Health Informatics; Kyoto University School of Public Health; Kyoto Japan
2. Department of Oral Epidemiology; Graduate School of Biomedical and Health Sciences; Hiroshima University; Hiroshima Japan
3. Gerodontology and Oral Rehabilitation; Department of Gerontology and Gerodontology; Graduate School of Medical and Dental Sciences; Tokyo Medical and Dental University; Tokyo Japan