1. Department of Otolaryngology, College of Medicine Konkuk University, Chungju, Korea.
2. Konkuk University Chungju Hospital Research Institute of Clinical Medicine, Chungju, Korea.
3. Department of Family Medicine, College of Medicine Konkuk University, Chungju, Korea.
4. Department of Neurosurgery, College of Medicine Konkuk University, Chungju, Korea.