1. Department of Otorhinolaryngology—Head and Neck Surgery, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
2. Department of Surgery, South Karelia Central Hospital, Lappeenranta, Finland
3. Department of Mechanical Engineering, Aalto University, Aalto, Finland
4. Department of Biomaterials Science and Turku Clinical Biomaterials Centre, Institute of Dentistry, University of Turku and Welfare Division, City of Turku, Turku, Finland
5. Department of Pediatric Surgery, Oulu University Hospital, Oulu, Finland
6. PEDEGO Research Unit and MRC Oulu, University of Oulu, Oulu, Finland
7. Division of Ear, Nose and Throat Diseases, Department of Clinical Sciences, Intervention and Technology, Karolinska Institutet and Karolinska University Hospital, Stockholm, Sweden