1. Department of Otorhinolaryngology, Head and Neck Surgery Carl‐Thiem‐Klinikum gGmbH Carl‐Thiem‐Street 111 03048 Cottbus Germany
2. Department of Otorhinolaryngology, Head and Neck Surgery Martin‐Luther‐University Halle—Wittenberg Halle (Saale) Germany
3. Department of Otorhinolaryngology, Head and Neck Surgery Klinikum Martha‐Maria Halle (Saale) Germany
4. Department of Otorhinolaryngology, Head and Neck Surgery Petrus‐Krankenhaus Carnaper Street 48 42283 Wuppertal Barmen Germany