1. Department of Microbiology and Immunology, Chung Shan Medical University, 110, 1st Section, Chien Kuo N. Road, Taichung, Taiwan, R.O.C.
2. Department of Periodontology, School of Dental Medicine, University of Pennsylvania, USA
3. Department of Oral Medicine, Chung Shan Medical University, Taiwan, R.O.C.