1. Department of Pathology, School of Dentistry, Aichi-Gakuin University, Nagoya, Japan.
2. Institute for Frontier Oral Science, Kanagawa Dental College, Yokosuka, Japan.
3. Department of Dental Bioengineering, School of Dentistry, Kanagawa, Dental College, Yokosuka, Japan.
4. Institute for Frontier Medical Science, Kyoto University, Kyoto, Japan.