1. Department of Global Oral Health, Radboud University Nijmegen Medical Centre, College of Dental Sciences, PO Box 9101, 6500 HB Nijmegen, The Netherlands;
2. The United Mission to Nepal Oral Health Programme, PO Box 126, Kathmandu, Nepal;
3. Population Oral Health, Faculty of Dentistry, University of Sydney, 1 Mons Road, Westmead, NSW 2145, Australia; and
4. National University Health System -NUHS-, Faculty of Dentistry, Department of Preventive Dentistry, Level 2, Dentistry Block, 5 Lower Kent Ridge Road, Singapore 119074