1. Department of Oral Molecular Biology, Course of Medical and Dental Sciences, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki 852–8588, Japan
2. Division of Molecular Microbiology, Iwate Medical University Graduate School of Dentistry, Iwate 028–3694, Iwate, Japan
3. Division of Periodontology, Iwate Medical University Graduate School of Dentistry, Iwate 020–0103, Japan
4. Department of Pediatric Dentistry, Course of Medical and Dental Sciences, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki 852–8588, Japan
5. Department of Oral Hygiene, Kansai Women's College, Kashiwara 582-0026, Osaka, Japan