1. Department of Oral and Maxillofacial Surgery, Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Korea.
2. Tooth Bioengineering National Research Laboratory, BK21, School of Dentistry, Seoul National University, Seoul, Korea.
3. Department of Biosystems and Biomaterials Science and Engineering, College of Agriculture and Life Science, Seoul National University, Seoul, Korea.
4. Department of Otolaryngology, School of Medicine, Ajou University, Suwon, Korea.