M.A. RYABOVA, N.A. SCHUMILOVA First Saint Petersburg State Medical University named after acad. I.P. Pavlov of the Ministry of Health of the Russian Federation, 6-8 Lev Tolstoy St., St. Petersburg, Russian Federation, 197022 Ryabova M.A. — D. Med. Sc., Professor of the Department of otorhinolaryngology with clinic, tel. (812) 499-71-76, e-mail: marinaryabova@mail.ru Shumilova N.A. — […]