1. Rhinology Study Group of the Young-Otolaryngologists of the International Federations of Oto-Rhino-Laryngological Societies (YO-IFOS), 70123 Paris, France
2. Service of Otolaryngology, Hospital Complex of Santiago de Compostela, 15701 Santiago de Compostela, Spain
3. Service of Otolaryngology, Rhinology and Skull Base Department, Marqués de Valdecilla Hospital, PC 39008 Santander, Spain
4. Department of Medical and Surgical Sciences and Advanced Technologies “GF Ingrassia” ENT Section, University of Catania, 95123 Catania, Italy
5. Service of Otolaryngology, Hospital Complex of La Coruña, PC 15001 La Coruña, Spain
6. Service of Otolaryngology, Rhinology and Skull Base Department, Clinic Hospital, PC 08036 Barcelona, Spain