1. Department of Otorhinolaryngology-Head and Neck Surgery, Veterans Health Service Daejeon Hospital, Daejeon, Republic of Korea
2. Department of Anesthesiology and Pain Medicine, Daejeon St. Mary’s Hospital, The Catholic University of Korea, College of Medicine, Daejeon, Republic of Korea
3. Department of Anesthesiology and Pain Medicine, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
4. Department of Pathology, Daejeon St. Mary’s Hospital, The Catholic University of Korea, College of Medicine, Daejeon, Republic of Korea