[1] Osmangazi Univ, Dept ORL Head & Neck Surg, Fac Med, Eskisehir, Turkey
[2] Kirikkale Univ, Dept Otorhinolaryngol Head & Neck Surg, Fac Med, TR-71000 Kirikkale, Turkey
[3] Gaziosmanpasa Taksim Educ & Res Hosp, Ear Nose & Throat ENT Clin, Istanbul, Turkey
[4] Business Adm President Russian Federat, Dept Med, Moscow, Russia
[5] Bayindir Goztepe Hosp, ENT Clin, Istanbul, Turkey
[6] Univ Siena, Dept ORL Head & Neck Surg, I-53100 Siena, Italy
[7] Yenimahalle Training & Res Hosp, ENT Clin, Ankara, Turkey
[8] Okmeydani Training & Res Hosp, ENT Clin, Istanbul, Turkey
[9] Tuzla State Hosp, ENT Clin, Istanbul, Turkey
[10] Russian Fed State Sci Ctr Childrens Hlth, Moscow, Russia
[11] Univ Med & Pharm Carol Davila, Sfanta Maria Hosp, Dept ORL Head & Neck Surg, Bucharest, Romania
[12] Univ Hosp Rebro KBC, ENT Dept, Zagreb, Croatia
[13] Univ Hosp Ctr Sestre Milosrdnice, Zagreb Sch Med, ENT Head & Neck Surg Dept, Zagreb, Croatia