1. Department of Periodontology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan;
2. Oral Health Science Center, Tokyo Dental College, Tokyo, Japan;
3. Department of Microbiology, Tokyo Dental College, Tokyo, Japan;
4. Department of Molecular Epidemiology, Medical Research Institute, Tokyo Medical and Dental University, Tokyo, Japan;
5. Department of Comprehensive Reproductive Medicine, Tokyo Medical and Dental University, Tokyo, Japan