1. Department of Otorhinolaryngology, University of Tampere, Tampere, Finland
2. Department of Otorhinolaryngology, Paijat-Hame Central Hospital, Lahti, Finland
3. School of Public Health, University of Tampere, Tampere, Finland
4. Department of Otorhinolaryngology, Mikkeli Central Hospital, Mikkeli, Finland
5. Department of Eye, Ear, and Oral Diseases, Tampere University Hospital, Tampere, Finland
6. Helsinki University Central Hospital, Skin and Allergy Hospital, Helsinki, Finland
7. Department of Otorhinolaryngology, Kanta-Hame Central Hospital, Hameenlinna, Finland
8. Transplantation Laboratory, Haartman Institute, University of Helsinki, Helsinki, Finland