1 Department of Oral Health Promotion, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan; Division for Regional Community Development, Liaison Center for Innovative Dentistry, Graduate School of Dentistry, Tohoku University, Sendai, Japan. Electronic address: j-aida@umin.ac.jp.
2 Fukai Institute of Health Science, Saitama, Japan.
3 WHO Collaborating Centre for Oral Health Inequalities and Public Health, Department of Epidemiology and Public Health, University College London, UK.