1 Department of Oral Health Science, Faculty of Nursing and Social Welfare, Kyushu University of Nursing and Social Welfare, 888, Tomio, Tamana-shi, 865-0062, Kumamoto, Japan. yodogawa@kyushu-ns.ac.jp.
2 Faculty of Medicine School of Health Sciences, Kagoshima University, 8-35-1, Sakuragaoka, Kagoshima-shi, 890-8544, Kagoshima, Japan.
3 Department of Oral Health Science, Faculty of Nursing and Social Welfare, Kyushu University of Nursing and Social Welfare, 888, Tomio, Tamana-shi, 865-0062, Kumamoto, Japan.
4 Department of Nursing, Faculty of Health Science, Aino University, 4-5-4, Higashi-Ohda, Osaka, 567-0012, Ibaraki-city, Japan.
5 National Institute of Public Health, 2-3-6 Minami, Wako-shi, 351-0197, Saitama, Japan.