1. Division of Oral Function and Rehabilitation, Department of Oral Health Science, Nihon University School of Dentistry at Matsudo,Matsudo, Chiba 271 – 8587, Japan
2. Department of Oral Diagnostics, Nihon University School of Dentistry at Matsudo,Matsudo, Chiba 271 – 8587, Japan
3. Nihon University Dental Hygiene School,School of Dentistry at Matsudo, Matsudo, Chiba 271 – 8587, Japan
4. Kitahara Gakuin College of Dental Hygiene,Matsudo, Chiba 270 – 0034, Japan
5. Yokohama City Center for Oral Health of Persons with Disabilities,Yokohama, Kanagawa 231 – 0012, Japan
6. Department of Histology, Nihon University School of Dentistry at Matsudo,Matsudo, Chiba 271 – 8587, Japan
7. Department of Community Oral Health,Nihon University School of Dentistry at Matsudo,Matsudo, Chiba 271 – 8587, Japan