1. ENT Department, St Mary’s Hospital, Imperial College, London, UK
2. 2nd Department of Otorhinolaryngology—Head and Neck Surgery, Papageorgiou University General Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece
3. Department of Otorhinolaryngology—Head and Neck Surgery, Papanikolaou General Hospital, Thessaloniki, Greece
4. 1st Department of Otorhinolaryngology—Head and Neck Surgery, AHEPA University General Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece