1. Section of Preventive and Public Health Dentistry, Division of Oral Health, Growth and Development, Faculty of Dental Science, Kyushu University, Fukuoka 812-8582, Japan
2. Department of Preventive Dentistry and Dental Public Health, School of Dentistry, Aichi Gakuin University, Aichi 464-8650, Japan
3. Department of Health Management, School of Oral Health Science, Kyushu Dental College, Kitakyushu 803-8580, Japan
4. Division of Research Management, Center for Cohort Studies, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan
5. Department of Environmental Medicine, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan