1. Department of Otorhinolaryngology Head & Neck Surgery , HEGP; University Paris Descartes Sorbonne Paris Cité; Paris France
2. Department of Oto-Rhino-Laryngology; Sant Joan University teaching Hospital; Reus Spain
3. Clinique d'Arcachon; Arcachon France
4. Department of Head and Neck Surgery; The University of Texas M. D. Anderson Cancer Center; Houston Texas U.S.A