1. Division of Oral Health and Society; Faculty of Dentistry; McGill University; Montreal QC Canada
2. Department of Epidemiology; University of Pittsburgh; Pittsburgh Pennsylvania
3. Epidemiology and Biostatistics Unit; INRS-Institut Armand-Frappier; Laval QC Canada
4. Institute of Health and Human Development; University of East London; London UK
5. UCL Research Department of Epidemiology and Public Health; University College London; London UK
6. Cancer Prevention and Control; Roswell Park Comprehensive Cancer Center; Buffalo New York