1. Otorhinolaryngology ServiceUniversity Hospital Gregorio MarañonMadrid Spain
2. Anatomy and Embryology Department, School of MedicineComplutense University of Madrid Spain
3. Medical Sciences DepartmentGerona University Spain
4. Otorhinolaryngology ServicePuerta de Hierro University HospitalMadrid Spain
5. Otorhinolaryngology ServiceUniversity Hospital Infanta LeonorMadrid Spain
6. Instituto de Investigación Sanitaria Gregorio MarañónMadrid Spain