1. Department of Oral Biosciences, The University of Hong Kong, Sai Ying Pun, Hong Kong SAR, People's Republic of China
2. Oral Diagnosis and Polyclinics, Faculty of Dentistry, The University of Hong Kong, Sai Ying Pun, Hong Kong SAR, People's Republic of China
3. Graduate School of Biomedical Science and Engineering, College of Medicine, Hanyang University, Seoul, Korea
4. Division in Anatomy and Developmental Biology, Department of Oral Biology, Oral Science Research Center, BK21 PLUS Project, Yonsei University College of Dentistry, Seoul, Korea