1. Department of Otorhinolaryngology and Head and Neck Surgery, Oulu University Hospital, Oulu, Finland
2. PEDEGO Research Unit, University of Oulu, Oulu, Finland
3. Medical Research Center Oulu, Oulu, Finland
4. Department of Otorhinolaryngology - Head and Neck Surgery, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
5. Department of Otorhinolaryngology and Head and Neck Surgery, Turku University Hospital and University of Turku, Turku, Finland
6. Department of Otorhinolaryngology-Head and Neck Surgery, Tampere University Hospital, Tampere, Finland
7. Department of Otorhinolaryngology- Head and Neck Surgery, Kuopio University Hospital, Kuopio, Finland
8. Research Program in Systems Oncology, Faculty of Medicine, University of Helsinki, Helsinki, Finland
9. Division of Ear, Nose and Throat Diseases, Department of Clinical Sciences, Intervention and Technology, Karolinska Institute and Karolinska University Hospital, Stockholm, Sweden