Association Between Tooth Loss, Receipt of Dental Care, and Functional Disability in an Elderly Japanese Population: The Tsurugaya Project.

OBJECTIVES

To examine whether number of remaining teeth and regular dental care affect incident functional disability in elderly Japanese adults.

DESIGN

Prospective cohort study.

SETTING

Tsurugaya district, Sendai, Japan.

PARTICIPANTS

Community-dwelling individuals aged 70 and older (N = 834).

MEASUREMENTS

The outcome measurement was incident functional disability, defined as first certification of long-term care insurance in Japan, which is determined on the basis of a strictly established uniform nationwide standard. During a median follow-up of 7.9 years (interquartile range 4.8-7.9 years), information on long-term care insurance was obtained from the Sendai Municipal Authority. Oral health was assessed according to number of remaining teeth and presence or absence of regular dental care. Data were also collected on age, sex, body mass index, medical history, smoking, alcohol consumption, duration of education, depressive symptoms, cognitive impairment, physical functioning, and social support.

RESULTS

Participants with 10 to 19 teeth (adjusted hazard ratio (aHR) = 1.42, 95% confidence interval (CI) = 1.03-1.94), one to nine teeth (aHR = 1.46, 95% CI = 1.04-2.03), and no teeth (aHR = 1.49, 95% CI = 1.03-2.14) were more likely to develop functional disability than those with 20 or more teeth. There was no significant difference in risk of functional disability between participants with 20 or more teeth and those with zero to 19 teeth who were receiving regular dental care, whereas those with zero to 19 teeth without regular dental care had a significantly greater risk of functional disability than those with 20 or more teeth (HR = 1.46, 95% CI = 1.11-1.92).

CONCLUSION

Tooth loss was associated with greater risk of functional disability in community-dwelling elderly Japanese. Regular dental care might moderate the risk of functional disability in elderly individuals with missing teeth.