New York University
Summary To quantify dose-response associations between tooth loss and the risk of cognitive decline and dementia. Design Longitudinal studies examining the association between tooth loss and cognitive function were systematically searched in 6 databases through March 1, 2020. The study adhered to the Preferred Reporting Items for Systematic Reviews and Meta- reporting guidelines. Analysis (PRISMA). Risk estimates were pooled using random effects models. Dose-response associations were assessed using generalized least squares spline models. Environment and participants Adults from the community, institution, outpatient, or inpatient setting were included in the meta-analysis. Measures Cognitive impairment and dementia were defined using neuropsychological testing, diagnostic criteria, or medical records. Tooth loss was self-reported or assessed by clinical examinations. Results Fourteen studies were entered into the meta-analysis, including 34,074 participants and 4,689 cases with decreased cognitive function. Participants with more tooth loss had a 1.48 times higher risk of developing cognitive impairment [95% confidence interval (CI) 1.18-1.87] and a 1.28 times higher risk of being diagnosed with dementia (95% CI 1.09-1.49); however, the association was not significant for participants wearing dentures (relative risk = 1.10, 95% CI: 0.90 to 1.11). Eight studies were included in the dose-response analysis and the data supported the use of linear models. Each additional tooth loss was associated with a 0.014 increased relative risk of cognitive decline and a 0.011 increased relative risk of dementia. Edentulous participants faced a 1.54 times greater risk of cognitive decline and a 1.40 times greater risk of being diagnosed with dementia. Conclusions and implications Moderate quality evidence suggested that tooth loss was independently associated with cognitive decline and dementia; The risk of decreased cognitive function increased with increasing number of missing teeth. Additionally, prompt prosthodontic or denture treatment can reduce the progression of cognitive impairment related to tooth loss. |
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Tooth loss is a risk factor for cognitive decline and dementia, and with each tooth lost, the risk of cognitive decline increases, according to a new analysis led by researchers at New York University Rory Meyers School of Nursing. and published in JAMDA .
However, this risk was not significant among older adults with dentures, suggesting that prompt treatment with dentures may protect against cognitive decline.
About one in six adults age 65 and older has lost all of their teeth , according to the Centers for Disease Control and Prevention. Previous studies show a connection between tooth loss and decreased cognitive function, and researchers offer a variety of possible explanations for this link. For one thing, missing teeth can cause chewing difficulties, which can contribute to nutritional deficiencies or promote changes in the brain.
A growing body of research also points to a connection between gum disease, a leading cause of tooth loss, and cognitive decline. Additionally, tooth loss may reflect lifelong socioeconomic disadvantages that are also risk factors for cognitive decline.
"Given the staggering number of people diagnosed with Alzheimer’s disease and dementia each year and the opportunity to improve oral health throughout life, it is important to gain a deeper understanding of the connection between poor oral health and decline. cognitive," Bei Wu said. Ph.D., Dean’s Professor in Global Health at New York University Rory Meyers School of Nursing and co-director of the New York University Aging Incubator, as well as lead author of the study.
Wu and colleagues conducted a meta-analysis using longitudinal studies of tooth loss and cognitive decline. The 14 studies included in their analysis involved a total of 34,074 adults and 4,689 cases of people with decreased cognitive function.
The researchers found that adults with more tooth loss had a 1.48 times higher risk of developing cognitive decline and a 1.28 times higher risk of being diagnosed with dementia, even after controlling for other factors.
However, adults with missing teeth were more likely to have cognitive impairment if they did not have dentures (23.8 percent) compared to those with dentures (16.9 percent); Additional analysis revealed that the association between tooth loss and cognitive decline was not significant when participants had dentures.
The researchers also conducted an analysis using a subset of eight studies to determine whether there was a "dose-response" association between tooth loss and cognitive decline; In other words, whether a greater number of missing teeth was related to a greater risk of cognitive decline.
Their findings confirmed this relationship: Each additional missing tooth was associated with a 1.4 percent increased risk of cognitive decline and a 1.1 percent increased risk of being diagnosed with dementia.
"This ’dose-response’ relationship between the number of teeth lost and the risk of decreased cognitive function substantially strengthens the evidence linking tooth loss with cognitive decline, and provides some evidence that tooth loss can predict the cognitive decline," said Xiang Qi, a PhD candidate at NYU Meyers.
"Our findings underscore the importance of maintaining good oral health and its role in helping to preserve cognitive function," Wu said.
