1. Department of Periodontics, Seoul St. Mary's Hospital, The Catholic University of Korea College of Medicine, Seoul, Korea.
2. Department of Oral Histology, Seoul National University School of Dentistry, Seoul, Korea.
3. Department of Biotechnology, Korea University College of Life Sciences and Biotechnology, Seoul, Korea.
4. Department of Periodontology, Institute of Oral Health Science, Ajou University School of Medicine, Suwon, Korea.