1. McGill University Faculty of Dentistry, 3640 University Street, Montreal, Quebec H3A 2B2, Canada
2. ; Community Dental Health Services Research Unit, University of Toronto, Canada
3. MCoill University School of Physical and Occupational Therapy
4. McGill University Faculty of Dentistry, 3640 University Street, Montreal, Quebec H3A 2B2, Canada, McGill University Faculty of Medicine, Joint Depts. of Epidemiology and Biostatistics, and Occupational Health, Jewish General Hospital, Lady Davis Institute for Medical Research, McGill University, Faculty of Medicine, Dept. of Oncology,