1. Ears, Nose, and Throat Unit, Azienda Ospedaliero Universitaria Pisana, Pisa, Italy
2. Ears, Nose, and Throat Unit, Azienda Ospedaliero Universitaria Ospedale di Circolo e Fondazione Macchi, Varese, Italy
3. Department of Systematic Anatomy, Medical University of Vienna, Vienna, Austria