1. Section of Preventive and Public Health Dentistry; Division of Oral Health, Growth and Development; Kyushu University Faculty of Dental Science; Fukuoka; Japan
2. Department of Endodontology and Operative Dentistry; Division of Oral Rehabilitation; Kyushu University Faculty of Dental Science; Fukuoka; Japan
3. Department of Health Management; School of Oral Health Science; Kyushu Dental College; Kitakyushu; Japan
4. Itoshima Dental Association; Itoshima; Japan
5. Rehabilitation Clinic for Speech and Swallowing Disorders; The Nippon Dental University Hospital; Tokyo; Japan