1. Department of Otorhinolaryngology, Otto-von Guericke-University of Magdeburg, Germany
2. Department of Otorhinolaryngology–Head, Neck, and Facial Plastic Surgery, Fulda Hospital, Academic Teaching Hospital of the University of Marburg, Fulda, Germany
3. Department of Otorhinolaryngology, University of Regensburg, Regensburg, Germany
4. Department of Otolaryngology–Head and Neck Surgery, University of Southern California School of Medicine, Los Angeles