Tooth Loss and Decline in Functional Capacity: A Prospective Cohort Study from the Japan Gerontological Evaluation Study.
To describe associations between tooth loss and changes in higher-level functional capacity.



Prospective cohort study.



Twenty-four Japanese municipalities between 2010 and 2013.



Functionally independent community-dwelling persons aged 65 and older (N = 62,333).



Self-reported number of teeth was used as an exposure variable. The outcome was changes in higher-level functional capacity measured using the Tokyo Metropolitan Institute of Gerontology Index of Competence (TMIG-IC), which consists of three domains: instrumental activities of daily living, intellectual activity, and social roles. The TMIG-IC score ranges from 0 (lowest function) to 13 (highest function). All covariates were chosen from baseline demographic, socioeconomic, health behavior, and health variables based upon evidence from previous studies. Inverse-probability weighting (IPW) with propensity score and multiple linear regression, estimating nonstandardized coefficients (β) and 95% confidence intervals (CIs), were used.



The baseline response rate was 65.2%, and the follow-up rate was 70.1%. During the follow-up period, participants' TMIG-IC score declined by an average of 0.247 points (standard deviation: 1.446). The results showed a significant dose-response association between tooth loss and decline in higher-level functional capacity in multiple linear regression models. IPW models estimated the increment in TMIG-IC score (β = 0.170, 95% CI = 0.114 to 0.227) if edentulous participants gained 20 or more natural teeth.



Tooth loss is associated with future decline in higher-level functional capacity. IPW models suggest that treatment for tooth loss attenuates decline in higher-level functional capacity.
Department of International and Community Oral Health, Graduate School of Dentistry, Tohoku University, Sendai, Japan.
Yukihiro
Y
Sato
Department of International and Community Oral Health, Graduate School of Dentistry, Tohoku University, Sendai, Japan.
Jun
J
Aida
Center for Preventive Medical Sciences, Chiba University, Chiba, Japan.|Department of Gerontological Evaluation, Center for Gerontology and Social Science, National Center for Geriatrics and Gerontology, Obu City, Japan.
Katsunori
K
Kondo
Department of International and Community Oral Health, Graduate School of Dentistry, Tohoku University, Sendai, Japan.
Toru
T
Tsuboya
Department of Epidemiology and Public Health, University College London, London, United Kingdom.
Richard G
RG
Watt
Division of Dental Sociology, Department of Oral Science, Graduate School of Dentistry, Kanagawa Dental University, Kanagawa, Japan.
Tatsuo
T
Yamamoto
Department of International and Community Oral Health, Graduate School of Dentistry, Tohoku University, Sendai, Japan.
Shihoko
S
Koyama
Department of International and Community Oral Health, Graduate School of Dentistry, Tohoku University, Sendai, Japan.
Yusuke
Y
Matsuyama
Department of International and Community Oral Health, Graduate School of Dentistry, Tohoku University, Sendai, Japan.
Ken
K
Osaka
D000203:Activities of Daily Living; D000368:Aged; D000369:Aged, 80 and over; D003071:Cognition; D005260:Female; D015577:Geriatric Assessment; D015438:Health Behavior; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D011446:Prospective Studies; D012307:Risk Factors; D057566:Self Report; D012919:Social Behavior; D016388:Tooth Loss / Q000453:epidemiology*
independent living; oral health; propensity score; tooth loss