1. Department of Otorhinolaryngology, Myongji Hospital, College of Medicine, Hanyang University, Goyang, Korea
2. Statistics Support Part, Kyung Hee Medical Science Research Institute, Kyung Hee University Medical Center, Seoul, Korea
3. Department of Otolaryngology–Head and Neck Surgery, Kyung Hee University Medical Center, Seoul, Korea
4. Department of Preventive Medicine, College of Korean Medicine, Kyung Hee University, Seoul, Korea