1. Department of Oral and Maxillofacial Diseases University of Helsinki Helsinki Finland
2. Clinical Dentistry Helsinki University Central Hospital Helsinki Finland
3. Institute of Dentistry University of Eastern Finland Kuopio Finland
4. Oral and Maxillofacial Diseases Kuopio University Hospital Kuopio Finland
5. Department of General Practice and Primary Health Care University of Helsinki Helsinki Finland
6. Helsinki University Central Hospital Helsinki Finland
7. Primary Health Care Unit Kuopio University Hospital Kuopio Finland
8. Folkhälsan Research Center Helsinki Finland
9. Social Services, Health Care and Rescue Services Division, Oral Health Care Helsinki Finland