1. Faculty of Dentistry, McGill University, 3640 University Street, M73, Montreal, Quebec H3A 2B2, Canada;
2. Centre for the Analysis of Cost-Effective Care, Montreal General Hospital Research Institute, and Department of Economics, McGill University;
3. Dept. of Prosthodontics and Oral Rehabilitation, School of Dental Sciences, University of Newcastle, Newcastle, United Kingdom;
4. Centre de Recherche en Sciences Neurologiques, Université de Montréal; and
5. Dept. of Epidemiology and Biostatistics, Faculty of Medicine, McGill University;