1. Department of Otorhinolaryngology, University of Cagliari, Azienda Ospedaliero Universitaria di Cagliari, Italy;
2. Ear, Nose and Throat Unit of SantOrsola-Malpighi Hospital, Bologna, Italy;
3. I.M. Sechenov First Moscow State Medical University, 11991, Moscow, Russia;
4. Ear, Nose and Throat Metropolitan Unit - Surgical Department - AUSL Bologna, Bellaria Hospital, Bologna, Italy