1. Tokyo Medical and Dental University, Pediatric Dentistry, Department of Orofacial Development and Function, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8549, Japan
2. Tokyo Medical and Dental University, Cariology and Operative Dentistry, Department of Restorative Sciences, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8549, Japan
3. Tokyo Medical and Dental University, Department of Cariology and Operative Dentistry, Global Center of Excellence (GCOE) Program, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8549, Japan
4. National Center for Geriatrics and Gerontology, Department for Advanced Dental Research, Center of Advanced Medicine for Dental and Oral Diseases, 35 Gengo, Morioka-cho, Obu, Aichi 474-8511, Japan