1. Department of Oral Biology, Faculty of Dentistry, University of Oslo, 0372 Oslo, Norway
2. Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, 0372 Oslo, Norway
3. Department of Oral Pathology, Faculty of Dentistry, Gazi University, Ankara 06510, Turkey
4. Department of Plastic and Reconstructive Surgery, Oslo University Hospital, 0372 Oslo, Norway