1. Oral Health Center of Expertise in Western Norway-Vestland, Bergen, Norway
2. Center for Disease Burden, The Norwegian Institute of Public Health, Bergen, Norway
3. Department of Preventive Dentistry, College of Dentistry, King Faisal University, Al Ahsa, Saudi Arabia
4. Public Dental Service, Vestland County, Norway
5. Department of Clinical Dentistry, Faculty of Medicine, University of Bergen, Bergen, Norway
6. Department of Biomedicine, University of Bergen, Bergen, Norway