1. Department of Otolaryngology; Samsung Changwon Hospital; Sungkyunkwan University School of Medicine; Changwon Korea
2. Department of Otolaryngology; Asan Medical Center; University of Ulsan College of Medicine; Seoul Korea
3. Department of Pathology; Asan Medical Center; University of Ulsan College of Medicine; Seoul Korea
4. Department of Biostatistics; Samsung Changwon Hospital; Sungkyunkwan University School of Medicine; Changwon Korea