1. Department of Nursing; Tohoku Fukushi University; Sendai Miyagi Japan
2. Division of International and Community Oral Health; Tohoku University Graduate School of Dentistry; Sendai Miyagi Japan
3. Division of Epidemiology; Department of Health Informatics and Public Health; Tohoku University School of Public Health; Tohoku University Graduate School of Medicine; Sendai Miyagi Japan
4. Department of Physiology; Nihon University School of Dentistry; Chiyoda-ku, Tokyo Japan
5. Department of Orthopaedic Surgery; Tohoku University School of Medicine; Sendai Miyagi Japan
6. Faculty of Comprehensive Welfare; Tohoku Fukushi University; Sendai Miyagi Japan
7. Division of Advanced Prosthetic Dentistry; Tohoku University Graduate School of Dentistry; Sendai Miyagi Japan