1. Department of Operative Dentistry, School of Dental Medicine, Tsurumi University, Yokohama, Japan
2. Department of Oral Hygiene, Tsurumi Junior College, Yokohama, Japan
3. Department of Fixed Prosthodontics, School of Dental Medicine, Tsurumi University, Yokohama, Japan
4. School of Dental Medicine, Tsurumi University, Yokohama, Japan
5. Center for Human Evolution Modeling Research, Primate Research Institute, Kyoto University, Inuyama, Japan
6. Center for the Evolutionary Origins of Human Behavior, Kyoto University, Inuyama, Japan
7. Language and Intelligence Section, Primate Research Institute, Kyoto University, Inuyama, Japan
8. Inuyama, Japan