○Yuri Namba¹, Yoshihiro Mitoh², Suzuka Yoshida³, Yohei Takeshita³, Junichi Asaumi³, Ryusuke Yoshida² (1. Department of Oral Diagnosis and Dentomaxillofacial Radiology, Okayama University Hospital, 2. Department of oral physiology, Faculty of Medici ne, Dentistry and Pharmaceutical Sciences, Okayama University, 3. Department of Oral and Maxillofacial Radiology, Faculty of Medici ne, Dentistry and Pharmaceutical Sciences, Okayama University)