1. Department of Otolaryngology-Head and Neck Surgery, Medical Laser Research Center, Dankook University, College of Medicine, Cheonan, Choongnam 330-714, Korea
2. Department of Otolaryngology-Head and Neck Surgery, Medical Laser Research Center, Dankook University, College of Medicine, Cheonan, Choongnam 330-714, Korea
3. Divison of Surgical Oncology, Department of Surgery, UCLA School of Medicine, Los Angeles, CA 90095-1782