1. Centre of Population Oral Health and Clinical Prevention Studies, Faculty of Dentistry, Universiti Teknologi MARA, Sungai Buloh Campus, 47000, Malaysia
2. Dept of Oral Sciences, School of Dentistry, The University of Otago, PO Box 647, Dunedin, New Zealand
3. Department of Public Health, University of Otago, 23a Mein St, Newtown, Wellington, New Zealand