1. Department of Pediatric Dentistry, School of Dentistry, and Department of Health Policy and Management, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, NC, USA
2. Department of Epidemiology and Public Health, University College London, Gower Street, London, UK
3. Bart’s and The London School of Medicine and Dentistry, London, UK
4. Department of Periodontics and Oral Medicine, University of Michigan School of Dentistry, Ann Arbor, MI, USA