1. Division of Population and Patient Health; King's College London Dental Institute at Guy's; King's College and St. Thomas’ Hospitals; London UK
2. Department of Oral Public Health; Institute of Dentistry; University of Eastern Finland; Kuopio Finland
3. The Living Environment and Health Unit; National Institute for Health and Welfare; Kuopio Finland
4. The Health Monitoring Unit; National Institute for Health and Welfare; Helsinki Finland
5. Department of Oral and Maxillofacial Diseases; Kuopio University Hospital; Kuopio Finland
6. Medical Research Center; Oulu University Hospital and University of Oulu; Oulu Finland