1. Department of Removable Prosthodontics and Geriatric Oral Health, Nihon University School of Dentistry at Matsudo, Matsudo, Chiba 271-8587, Japan
2. Research Institute of Oral Science, Nihon University School of Dentistry at Matsudo, Matsudo, Chiba 271-8587, Japan
3. Human Informatics and Interaction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8566, Japan
4. Department of Oral Diagnostics, Nihon University School of Dentistry at Matsudo, Matsudo, Chiba 271-8587, Japan
5. Dental Support Co. Ltd., Chiba, Chiba 261-8501, Japan
6. Department of Anesthesiology, Nihon University School of Dentistry at Matsudo, Matsudo, Chiba 271-8587, Japan