1 Department of Oral and Maxillofacial Radiology, School of Dentistry, Matsumoto Dental University, 1780 Gobara, Hirooka, Shiojiri, Nagano, 399-0781, Japan. akira.taguchi@mdu.ac.jp.
2 Department of Hard Tissue Research, Graduate School of Oral Medicine, Matsumoto Dental University, 1780 Gobara, Hirooka, Shiojiri, Nagano, 399-0781, Japan. akira.taguchi@mdu.ac.jp.