[1] Nippon Dent Univ, Sch Life Dent Niigata, Dept Internal Med, Niigata 9518580, Japan
[2] Nippon Dent Univ, Sch Life Dent Tokyo, Dept Dev & Regenerat Dent, Chiyoda Ku, Niigata 1028159, Japan
[3] Univ Tsukuba, Fac Med, Dept Neurosurg, Lab Clin Regenerat Med, Lab Adv Res D 326,1-1-1 Tennodai, Tsukuba, Ibaraki 3058575, Japan