1. School of Medicine, Democritus University of Thrace, 68100 Alexandroupoli, Greece
2. First Department of Otorhinolaryngology—Head and Neck Surgery, Faculty of Medicine, National and Kapodistrian University of Athens, 114 Vas Sofias Avenue, 11527 Athens, Greece
3. Laboratory Histology–Embryology, Faculty of Medicine, National and Kapodistrian University of Athens, 75 Mikras Asias Street, Goudi, 11527 Athens, Greece
4. ENT Department, Athens General Hospital “ELPIS”, 7 Dimitsanas Street, 11522 Athens, Greece