1. Department of Otorhinolaryngology, Hospital Quiron Salud Marbella, Av. Severo Ochoa 22, 29603 Marbella, Spain
2. Department of Otorhinolaryngology, Hospital Fuenlabrada, Universidad Rey Juan Carlos I, 28032 Madrid, Spain
3. Department of Otorhinolaryngology, Clinica Universitaria de Navarra, 31008 Pamplona, Spain
4. Department of Otorhinolaryngology, Hospital Universitario Virgen de Valme, 41014 Seville, Spain
5. Department of Otorhinolaryngology, Hospital La Linea, 11300 La Linea de la Concepción, Spain