1 Division of Pathology, Department of Diagnostic and Therapeutic Sciences, Meikai University School of Dentistry, 1-1 Keyakidai, Sakado, Saitama, 350-0283, Japan.
2 Department of Diagnostic Pathology, Tsurumi University Dental Hospital, 2-1-3 Tsurumi, Tsurumi-ku, Yokohama, 230-8501, Japan.
3 Department of Diagnostic Pathology, Tsurumi University Dental Hospital, 2-1-3 Tsurumi, Tsurumi-ku, Yokohama, 230-8501, Japan. ito-yu@tsurumi-u.ac.jp.