1. Institute of Dentistry; University of Eastern Finland; Kuopio Finland
2. Keski-Satakunta's Health Care Federation of Municipalities; Harjavalta Finland
3. Institute of Dentistry; University of Turku; Turku Finland
4. Turku Clinical Research Centre; Turku University Hospital; Turku Finland
5. Public Health Evaluation and Projection Unit; National Institute for Health and Welfare (THL); Helsinki Finland
6. Department of Oral and Maxillofacial Diseases; Kuopio University Hospital; Kuopio Finland