1. Center of Otolaryngology, Head and Neck Surgery of Mittelhessen,Marburg, Germany
2. Department of Otolaryngology, Head and Neck Surgery, Phillipp University, Marburg, Germany
3. Department of Orofacial Prosthodontics and Craniomandibular Function,Dental School,Philipps-University, Marburg, Germany
4. Department of Otolaryngology, Head and Neck Surgery, Sana Kliniken Leipziger Land,Borna,Germany
5. Department of Otolaryngology, Head and Neck Surgery, Borromäus Hospital, Leer, Germany