1. Division of Cancer Epidemiology; McGill University; Montreal Quebec Canada
2. Division of Oral Health and Society, Faculty of Dentistry; McGill University; Montreal Quebec Canada
3. Epidemiology and Biostatistics Unit; INRS-Institut Armand-Frappier; Laval Quebec Canada
4. Department of Cancer Prevention and Control; Roswell Park Cancer Institute; Buffalo New York
5. Department of Radiation Oncology; Hôpital Notre-Dame du Centre de Recherche du Centre Hospitalier de l'Université de Montréal; Montreal Quebec Canada
6. Department of Hemato-Oncology; Hôpital Notre-Dame du Centre Hospitalier de l'Université de Montréal; Montreal Quebec Canada
7. Department of Microbiology and Infectious Diseases; Hôpital Notre-Dame du Centre de Recherche du Centre Hospitalier de l'Université de Montréal; Montreal Quebec Canada
8. Department of Otolaryngology-Head and Neck Surgery, Faculty of Medicine; McGill University; Montreal Quebec Canada