E.M. POKROVSKAYA1, V.N. KRASNOGEN2, S.V. KHALIULLINA3 1«Mart» Medical Center, 16 Kutuy St., Kazan, Russian Federation, 420000 2Kazan State Medical Academy, 36 Butlerov St., Kazan, Russian Federation, 420012 3Kazan State Medical University, 49 Butlerov St., Kazan, Russian Federation, 420012 Pokrovskaya E.M. — Cand. Med. Sc., Head of Otorhinolaryngology Department, tel. +7-917-263-90-96, e-mail: epokrunia@inbox.ru Krasnozhen V.N. — […]