1. Department of Preventive Dental Sciences, College of Dentistry, Imam Abdulrahman Bin Faisal University, P O Box 1982, Dammam 31441, Saudi Arabia
2. Department of Community & Preventive Dentistry, FMH College of Medicine & Dentistry, Lahore, Pakistan
3. University of Toronto, Faculty of Dentistry, 124 Edward Street, Toronto, Ontario M5G 1G6, Canada
4. University of Western Ontario, Faculty of Health Science, 1151 Richmond St, London, Ontario N6A 5B9, Canada