1. Department of Health Policy Science, Graduate School of Medical Science Yamagata University Yamagata Japan
2. Yamagata City Hospital Saiseikan Yamagata Japan
3. Department of Surgery I, Graduate School of Medical Science Yamagata University Yamagata Japan
4. Department of International and Community Oral Health Tohoku University Graduate School of Dentistry Sendai Japan
5. Sakakibara Heart Institute Fuchu Japan