1. Bristol Dental School, Faculty of Health Sciences University of Bristol Bristol UK
2. Medical Research Council Integrative Epidemiology Unit, Population Health Sciences, Bristol Medical School, Faculty of Health Sciences University of Bristol Bristol UK
3. Division of Pediatric and Public Health, Adams School of Dentistry University of North Carolina at Chapel Hill Chapel Hill North Carolina USA
4. Department of Odontology Umeå University Umeå Sweden
5. Department of Epidemiology, Gillings School of Global Public Health University of North Carolina at Chapel Hill Chapel Hill North Carolina USA