1. Department of Otorhinolaryngology, University of Basel, Kantonsspital, CH-4031, Basel
2. EDP Department of Hoffmann-La, Roche AG, CH-4000, Basel
3. Department of Otorhinolaryngology, University of Bern, Inselspital, CH-3010 Bern and Department of Otorhinolaryngology, Kantonsspital, CH-5000, Aarau, Switzerland