1. Department of Oral Disease Research, Geroscience Research Center, National Center for Geriatrics and Gerontology, Obu 474-8511, Japan
2. Department of Geriatric Oral Science, Graduate School of Dentistry, Tohoku University, Sendai 980-8575, Japan
3. Research Department, Daiichi Sankyo Healthcare Co., Ltd., Tokyo 140-8710, Japan
4. Section of Community Oral Health and Epidemiology, Division of Oral Health, Technology and Epidemiology, Faculty of Dental Science, Kyushu University, Fukuoka 812-8582, Japan
5. Department of Operative Dentistry, School of Dentistry, Aichi Gakuin University, Nagoya 464-8650, Japan