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