1. Institute of Dentistry University of Eastern Finland Kuopio Finland
2. Neurology, Institute of Clinical Medicine University of Eastern Finland Kuopio Finland
3. Department of Oral and Maxillofacial Diseases Kuopio University Hospital Kuopio Finland
4. Division of Clinical Geriatrics, NVS Karolinska Institute Stockholm Sweden
5. Aging Epidemiology Research Unit, School of Public Health Imperial College London London UK