1. Department of Otorhinolaryngology-Head & Neck Surgery, Hallym University Sacred Heart Hospital, Hallym University College of Medicine, Anyang, South Korea
2. Department of Otorhinolaryngology-Head and Neck Surgery, Chungbuk National University College of Medicine, Chungbuk National University Hospital, Cheongju, South Korea
3. Department of Neurosurgery, Chungbuk National University College of Medicine, Chungbuk National University Hospital, Cheongju, South Korea.