1. Shouseikai Ashiro Clinic, 129, Kawahara, Ashiro Town, Iwate Pref., 028-7527, Japan
2. Department of Surgery, Shouseikai Takizawa Central Hospital, 1-104, Ukai-Kitsunehora, Takizawa Village, Iwate Pref., 020-0172, Japan
3. Department of Periodontology, School of Dentistry, Iwate Medical University, 1-3-27, Chuodori, Morioka, 020-0085, Japan