1. Department of Otorhinolaryngology, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, P.R. China;
2. Department of Otorhinolaryngology, Hangzhou First People’s Hospital, Hangzhou, P.R. China;
3. Department of Otorhinolaryngology, People’s Hospital of Kaihua, Kaihua, P.R. China