1. College of Medicine and University Hospitals, King Saud University
2. Department of Dental Public Health, School of Dental Medicine, Case Western Reserve University
3. Department of Dental Public Health, College of Dentistry, King Saud Bin Abdulaziz University for Health Sciences
4. Department of Dental Health, College of Applied Medical Sciences, King Saud University
5. Division of Periodontology, College of Dentistry, The Ohio State University