1. Research Unit of Oral Health Sciences, Faculty of Medicine University of Oulu Oulu Finland
2. Medical Research Center Oulu University Hospital and University of Oulu Oulu Finland
3. Oulu University Hospital Oulu Finland
4. Department of Oral and Maxillofacial Diseases Turku University Hospital Turku Finland
5. Institute of Dentistry University of Helsinki Helsinki Finland
6. Helsinki University Hospital Helsinki Finland
7. University of Oulu Oulu Finland
8. Institute of Dentistry University of Turku Turku Finland