1. Department of Otorhinolaryngology-Head and Neck Surgery, Keelung Chang Gung Memorial Hospital, Keelung City, Taiwan
2. Department of Otorhinolaryngology-Head and Neck Surgery, Lotung Poh-Ai Hospital, Yilan County, Taiwan
3. Department of Otorhinolaryngology-Head and Neck Surgery, Linkou Chang Gung Memorial Hospital, Chang Gung University, Taoyuan City, Taiwan