1. Department of Periodontology, Research Institute of Periodontal Regeneration, Yonsei University College of Dentistry, Seoul, Korea.
2. Department of Periodontology and Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Korea.
3. Private practice, Mapo Acro Dental Clinic, Seoul, Korea.
4. Private practice, Seoul Ace Dental Clinic, Seoul, Korea.
5. Private Practice, Lausanne, Switzerland.
6. Postgraduate Program in Periodontology, Faculty of Odontology, Complutense University of Madrid, Madrid, Spain.