1. Department of Otorhinolaryngology Head and Neck Surgery; The First Hospital of China Medical University; Shenyang 110001 Liaoning China
2. Department of Otorhinolaryngology Head and Neck Surgery; Affiliated Hospital of Inner Mongolia University for the Nationalities; Tongliao 028007 Inner Mongolia China
3. Department of Oral Maxillofacial Surgery; Stomatology Hospital of China Medical University; Shenyang 110002 Liaoning China