1. PhD Candidate, Department of Social Dentistry, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and VU University, 1081 LA Amsterdam, The Netherlands; Senior Lecturer, Faculty of Dentistry, SEGi University, No 9 Jalan Teknologi, Kota Damansara, PJU-5, Petalingjaya-47810, Selangor, Malaysia
2. PhD Candidate, School of Public Health, The University of Queensland, Public Health Building, Cnr Wyndham St and Herston Rd, Herston QLD 4006, Australia
3. Professor, Department of Social Dentistry, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and VU University, 1081 LA Amsterdam, The Netherlands; School of Health Sciences of Salford University, Manchester, UK