1. Center for Rhinology and Allergology, Wiesbaden, Germany
2. Department of Otorhinolaryngology, Mainz University Medical Center, Mainz, Germany
3. Department of Otorhinolaryngology, Head and Neck Surgery, University Medical Center of Eberhard-Karls University, Tübingen, Germany
4. Clinic and Polyclinic for Otorhinolaryngology, University Hospital Carl Gustav Carus, TU Dresden, Dresden, Germany
5. Practice for Ear, Nose and Throat Medicine, Clinic RKM 740, Düsseldorf, Germany