1. Department of Otorhinolaryngology Head and Neck Surgery, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, P.R. China
2. Department of Otorhinolaryngology Head and Neck Surgery, Beijing Anzhen Hospital, Capital Medical University, Beijing 100730, P.R. China
3. Department of Otorhinolaryngology, Inner Mongolia Medical University Affiliated Hospital, Hohhot, Inner Mongolia 010050, P.R. China