1. Department of Otorhinolaryngology, Head and Neck Surgery, University Clinic Halle, Halle, Germany;
2. Department of Otorhinolaryngology, Head and Neck Surgery, Evangelical Hospital, Vienna, Austria;
3. Department of Otorhinolaryngology, Head and Neck Surgery, University of Munich, Munich, Germany;
4. ENT, Head and Neck Surgery, ENT Center Mangfall-Inn, Rosenheim, Germany