1. Institute of Dentistry, University of Helsinki, and Department of Oral and Maxillofacial Diseases, Helsinki University Central Hospital, Helsinki, Finland,
2. Division of Periodontology, Institute of Odontology, Karolinska Institutet, Huddinge, Sweden
3. Department of Molecular Medicine, National Public Health Institute, Helsinki, Finland
4. Institute of Dentistry, University of Helsinki, and Department of Oral and Maxillofacial Diseases, Helsinki University Central Hospital, Helsinki, Finland