1. College of Dentistry; Preventive and Community Dentistry; The University of Iowa; Iowa City IA USA
2. College of Dentistry; The University of Iowa; Iowa City IA USA
3. Pediatric Dentistry; School of Dentistry at University of Alabama; Birmingham AL USA
4. College of Public Health; Department of Biostatistics; University of Alabama at Birmingham; Birmingham AL USA
5. College of Public Health; Department of Epidemiology; University of Alabama at Birmingham; Birmingham AL USA
6. Department of Health Behavior; School of Public Health and School of Nursing, University of Alabama at Birmingham; Birmingham AL USA
7. College of Public Health; Biostatistics; The University of Iowa; Iowa City IA USA