1. Department of Otorhinolaryngology Fondazione I.R.C.C.S. Policlinico San Matteo, University of Pavia Pavia Italy
2. Otorhinolaryngology Unit Azienda Ospedaliera Papa Giovanni XXIII Bergamo Italy
3. Department of Pediatrics Fondazione I.R.C.C.S. Policlinico San Matteo, University of Pavia Pavia Italy