1. Department of Otorhinolaryngology Hannover Medical School Hannover Germany
2. Department of Otorhinolaryngology Helios Hospital Berlin‐Buch Berlin Germany
3. Department of Otolaryngology ‐ Head and Neck Surgery Soroka University Medical Center Be'er Sheva Israel
4. Department of Otorhinolaryngology Helios Hospital Hildesheim Hildesheim Germany