1. Institute of Head and Neck Diseases, Evangelical Hospital, 1180 Vienna, Austria
2. Department of Otorhinolaryngology, Head and Neck Surgery, Clinical Hospital Center Rijeka, 51000 Rijeka, Croatia
3. Faculty of Medicine, University of Rijeka, 51000 Rijeka, Croatia
4. Department of Otorhinolaryngology, Head and Neck Surgery, Medical University Vienna, 1090 Vienna, Austria
5. Center for Medical Statistics, Informatics and Intelligent Systems, Section for Medical Statistics, Medical University Vienna, 1090 Vienna, Austria
6. Department of Audiology and Phoniatrics, Clinical Hospital Centre Rijeka, 51000 Rijeka, Croatia
7. Clinical Department of Pathology and Cytology, Clinical Hospital Center Rijeka, 51000 Rijeka, Croatia