1. Department of Pediatric Dentistry, Oral Science Research Center, College of Dentistry, Yonsei University, Seoul, Korea.
2. Division in Anatomy and Developmental Biology, Department of Oral Biology, College of Dentistry, Yonsei University, Seoul, Korea.
3. Department of Periodontology, Research Institute for Periodontal Regeneration, College of Dentistry, Yonsei University, Seoul, Korea.