1. Department of Periodontology; Kagoshima University Graduate School of Medical and Dental Sciences; Kagoshima; Japan
2. Department of Oral Microbiology; Kagoshima University Graduate School of Medical and Dental Sciences; Kagoshima; Japan
3. Department of Reproductive Pathophysiology and Obstet-Gynecology; Kagoshima University Graduate School of Medical and Dental Sciences; Kagoshima; Japan
4. Department of Obstetrics and Gynecology; Kagoshima City Hospital; Kagoshima; Japan