1. School of Clinical Medicine, Weifang Medical University, Weifang, China
2. Department of Otorhinolaryngology, Head and Neck Surgery, Yantai Yuhuangding Hospital, Qingdao University, Yantai, China
3. Shandong Provincial Clinical Research Center for Otorhinolaryngologic Diseases, Yantai, China
4. Department of Pathology, Yantai Yuhuangding Hospital, Qingdao University, Yantai, China