1. Department of Otolaryngology–Head and Neck Surgery, Dr. Lutfi Kirdar Kartal Training and Research Hospital, Istanbul, Turkey
2. Department of Otolaryngology–Head and Neck Surgery, Sultanbeyli State Hospital, Istanbul
3. Department of Gastroenterology, Cerrahpasa Faculty of Medicine, Istanbul University
4. Department of Otolaryngology–Head and Neck Surgery, Bahcelievler Huzur Hospital, Istanbul