1. Department of Otorhinolaryngology, West China Hospital, West China Medical School, Sichuan University, Chengdu, Sichuan 610041, P.R. China
2. Department of Otorhinolaryngology, Head and Neck Surgery, The First Affiliated Hospital of Chengdu Medical College, Chengdu, Sichuan 610000, P.R. China
3. Upper Airways Research Laboratory, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China
4. Upper Airways Research Laboratory, Department of Otorhinolaryngology, Ghent University, 9000 Ghent, Belgium