1. Department of Dental Public Health University of Maryland School of Dentistry Baltimore Maryland USA
2. Department of Preventive and Restorative Dental Sciences, Division of Oral Epidemiology and Dental Public Health University of California San Francisco School of Dentistry San Francisco California USA
3. Department of Social, Behavioral, and Population Sciences, School of Public Health and Tropical Medicine Tulane University New Orleans Louisiana USA
4. Department of Health Behavior and Health Education, School of Public Health University of Michigan Ann Arbor Michigan USA