1. Hospital Naval de San Carlos, Otorhinolaryngology Department Hospital Naval de San Carlos, San Fernando Cadiz, Spain
2. Othorhinolaryngology Department, Hospital Quironsalud Marbella, Marbella, Spain
3. Otorhinolaryngology Department, Hospital Universitario de Fuenlabrada. Universidad Rey Juan Carlos. Hospital Sanitas La Zarzuela. Madrid. Spain
4. Othorhinolaryngology Department, Hospital Quironsalud Campo de Gibraltar, Spain
5. Otorhinolaryngology Department, Hospital Naval de San Carlos, San Fernando Cadiz, Spain
6. Otorhinolaryngology Department, Hospital la Merced Osuna Sevilla, Spain