1. Assistant Professor, Division of Oral Medicine and Radiology, Faculty of Dentistry, The University of Western Ontario, London, Ontario CA N6A 5C1.
2. Professor and Chairman, Division of Oral Medicine and Radiology, Faculty of Dentistry, The University of Western Ontario, US.
3. Assistant Director, Biostatistical Support Unit, Department of Epidemiology and Biostatistics, The University of Western Ontario, US.