1. Department of Otorhinolaryngology, Head and Neck Surgery; Ludwig Maximilians University Munich; Germany
2. ENT-Center Mangfall-Inn; Rosenheim Germany
3. Department of Surgery; Beth Israel Deaconess Medical Center; Harvard Medical School; Boston MA USA
4. Rhinology Center; ENT-Clinic Munich Bogenhausen; Dr. Gaertner GmbH; Munich Germany