1. Department of Otorhinolaryngology – Head and Neck Surgery, University of Helsinki and Helsinki University Hospital, Helsinki, Finland;
2. Department of Pathology, Haartman Institute and HUSLAB, University of Helsinki and Helsinki University Hospital, Helsinki, Finland;
3. Department of Surgery, University of Helsinki and Helsinki University Hospital, Helsinki, Finland;
4. Department of Radiology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland;
5. Department of Oral Pathology and Oral Radiology, University of Turku and Turku University Hospital, Turku, Finland;
6. Division of Ear, Nose and Throat Diseases, Department of Clinical Sciences, Intervention and Technology, Karolinska Institutet and Karolinska Hospital, Stockholm, Sweden