1. Faculty of Health Sciences, School of Medicine, Institute of Dentistry, University of Eastern Finland, Kuopio, Finland;
2. Institute of Dentistry, University of Eastern Finland, Kuopio, Finland;
3. Department of Oral and Maxillofacial Diseases, Kuopio University Hospital, Kuopio, Finland;
4. Public Health Evaluation and Projection Unit, National Institute for Health and Welfare (THL), Helsinki, Finland;
5. Research Unit of Oral Health Sciences, Faculty of Medicine, University of Oulu, Oulu, Finland;
6. Oral and Maxillofacial Department, Medical Research Center Oulu, Oulu University Hospital, Oulu, Finland