Kh.A. ALIMETOV1, Sh.M. ISMAGILOV1, R.S. BAKIROV2, R.A. MUKHAMADIEV2, R.V. LATYPOV1 1Kazan State Medical University, 49 Butlerov St., Kazan, Russian Federation, 420012 2City Clinical Hospital № 18, 2 Mavlyutov St., Kazan, Russian Federation, 420001 Alimetov Kh.A. — D. Med. Sc., Professor, Head of the ENT Department, tel. +7-917-908-21-47, e-mail: [email protected] Ismagilov Sh.M. — Cand. Med. Sc., […]