1. Department of Otorhinolaryngology, Academic Medical Center, Amsterdam, The Netherlands
2. Department of Otorhinolaryngology, Head and Neck Surgery, University Hospitals Leuven, Cathologic University of Leuven, Leuven, Belgium
3. Department of Otorhinolaryngology and Head and Neck Surgery, Radboud University Medical Centre Nijmegen, Nijmegen, The Netherlands
4. GlaxoSmithKline, Research Triangle Park, North Carolina