U Alkan1, Y Nachalon2, Y Vaisbuch2, O Katz2, Y Hamzany1, Y Stern2,3. 1. Department of Otorhinolaryngology - Head and Neck Surgery, Rabin Medical Center - Beilinson Hospital, Petach Tikva, Israel. 2. Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel. 3. Pediatric Upper Airway Unit, Schneider Children's Medical Center of Israel, Petach Tikva, Israel.