I.G. ANDREEVA1,2, V.N. KRASNOZHON1, E.V. LUCHKINA2 1 Kazan State Medical Academy — Branch Campus of the FSBEI FPE RMACPE MOH Russia, 36 Butlerov Str., Kazan, Russian Federation, 420012 2 Children’s Republican Clinical Hospital, 140 Orenburgskiy trakt, Kazan, Russian Federation, 420138  Andreeva I.G. — doctor-otolaryngologist, tel. +7-905-025-57-17, e-mail: [email protected] Krasnozhon V.N. — D. Med. Sc., Professor, […]