1. Institute of Dentistry, University of Helsinki and Department of Oral and Maxillofacial Diseases, Helsinki University Central Hospital, Helsinki, Finland
2. Department of Health and Functional Capacity
3. Department of Bacterial and Inflammatory Diseases, National Public Health Institute (KTL), Helsinki, Finland
4. Institute of Dentistry, University of Oulu, Oulu, Finland
5. Institute of Dentistry, University of Turku, Turku, Finland