1. HNO-Praxis Am Hanse-Viertel, Hamburg, Germany
2. Department of Otorhinolaryngology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania
3. HNO-Zentrum Rhein-Neckar, Mannheim, Germany
4. Department of Otorhinolaryngology, Head and Neck Surgery, Universitatsklinikum Mannheim, Mannheim, Baden-Württemberg, Germany
5. Department of Otolaryngology, Head and Neck Surgery, University Erlangen-Nuremberg, Erlangen, Germany