Danni Wang1, Shouqin Zhao2, Yanling Zhao1, Shubin Chen1, Lin Yang1. 1. Department of Otolaryngology Head and Neck Surgery, Beijing Tongren Hospital, Capital Medical University; Key Laboratory of Otolaryngology Head and Neck Surgery (Capital Medical University), Ministry of Education, Beijing 100730, China. 2. Department of Otolaryngology Head and Neck Surgery, Beijing Tongren Hospital, Capital Medical University; Key Laboratory of Otolaryngology Head and Neck Surgery (Capital Medical University), Ministry of Education, Beijing 100730, China. Email: shouqinzhao@yahoo.com.