1. Statistical Bureau of the Ministry of Internal Affairs and Communications The estimation of Japanese population, Table 3 http://www.stat.go.jp/data/jinsui/2009np/index.htm
2. Elongation of life expectancy may accompany shift of medical cost to older adults;Sasaki;J Am Geriatr Soc,1997
3. Ministry of Health, Labour and Welfare The Survey of National Medical Expenditure in 2007, Table 1 http://www.mhlw.go.jp/toukei/saikin/hw/k-iryohi/07/kekka1.html
4. Ministry of Health, Labour and Welfare The Survey of National Medical Expenditure in 2007, Table 5 http://www.mhlw.go.jp/toukei/saikin/hw/k-iryohi/07/kekka5.html
5. How dentition status and masticatory function affect nutrient intake;Krall;J Am Dent Assoc,1998