1. Department of Periodontology School of Dentistry University of North Carolina at Chapel Hill Chapel Hill North Carolina, USA
2. Department of Oral and Craniofacial Health Sciences School of Dentistry University of North Carolina at Chapel Hill Chapel Hill North Carolina, USA
3. Department of Pediatric Dentistry School of Dentistry University of North Carolina at Chapel Hill Chapel Hill North Carolina, USA
4. Department of Epidemiology Gillings School of Global Public Health University of North Carolina at Chapel Hill Chapel Hill North Carolina, USA