1. Department of Otorhinolaryngology/Head and Neck Surgery; Queen's Medical Centre; Nottingham United Kingdom
2. Department of Otorhinolaryngology; Academic Medical Center; Amsterdam the Netherlands
3. 1st Academic ENT Department; AHEPA University Hospital; Aristotle University of Thessaloniki; Thessaloniki Greece
4. Department of Otorhinolaryngology/Head and Neck Surgery; Center for Facial Plastic and Reconstructive Surgery, University Medical Center; Utrecht the Netherlands