1. Department of Oral Pathology, BK 21 Project, School of Dentistry, Chosun University, Gwangju, Korea.
2. Department of Oral & Maxillofacial Surgery, BK 21 Project, School of Dentistry, Chosun University, Gwangju, Korea.
3. Department of Oral Pathology, Oral Cancer Research Institute, Yonsei University College of Dentistry, Seoul, Korea.