Investigators have examined the association between oral diseases and cognitive function among older adults.
Prior research has provided evidence of a potential link between oral diseases and cognitive decline and dementia as a result of the shared inflammatory pathways between the conditions. For instance, researchers have shown that chronic oral bacterial infections and dysbiosis could contribute to inflammation. Additionally, patients with cognitive decline may be more likely to follow poorer oral health habits.
In a cross-sectional study, published in Oral Diseases, the investigators used the 2011 to 2012 and 2013 to 2014 National Health and Nutrition Examination Survey to analyze the bidirectional relationship between periodontitis, dental caries, and tooth loss and reduced cognitive function in 2,508 participants aged 60 years and older on the basis of three domains: memory, processing speed, and executive function. They then performed three statistical models to elucidate the correlations between oral diseases and cognitive function—including regress oral disease on cognitive function, regress cognitive function on oral disease, and structural equation modeling in which cognition and oral disease were latent variables.
The investigators found that the patients with periodontitis, a higher caries rate, or more tooth loss had a greater likelihood of having lower global cognitive scores. For instance, processing speed was linked to all three oral diseases, periodontitis was correlated with memory, and both tooth loss and dental carries were connected with executive function. Additionally, the number of missing teeth was also linked to worse executive function (beta = –0.01, 95% confidence interval [CI] = –0.02 to –0.00) and processing speed (beta = –0.02, 95% confidence interval [CI] = –0.03 to –0.01); the number of decayed, missing, and filled teeth was linked to poorer processing speed (beta = –0.01, 95% confidence interval [CI] = –0.02 to –0.01); and periodontitis was linked to declines in memory (beta = –0.15, 95% confidence interval [CI] = –0.30 to 0.00) and processing speed (beta = –0.16, 95% confidence interval [CI] = –0.28 to –0.04).
In the models where cognitive function was the outcome, the investigators revealed that periodontitis (beta = –0.39, 95% CI = –0.69 to –0.10), more missing teeth (beta = –0.04, 95% CI = –0.06 to –0.02), and more dental caries (decayed, missing, and filled teeth beta = –0.03, 95% CI = –0.06 to –0.01) had an inverse relationship with cognitive health.
For the models where oral diseases were the outcomes, periodontitis was associated with worse memory (odds ratio [OR] = 0.93, 95% CI = 0.87–1.00) and processing speed (OR = 0.88, 95% CI = 0.81–0.96); a greater number of decayed, missing, and filled teeth was inversely associated with processing speed (beta = –0.36, 95% CI = –0.58 to –0.14); and a higher number of missing teeth was associated with lower executive function (OR = –0.06, 95% CI = –0.09 to –0.03) and processing speed (beta = –0.07, 95% CI = –0.11 to –0.04).
The findings indicated that there may be a robust bidirectional relationship between oral diseases and cognitive function in this patient population. The investigators emphasized the significance of practicing beneficial oral health and cognitive function behaviors in order to mitigate the risk of developing either condition.
The study authors asserted, “While we cannot conclude whether the association between oral disease and poor cognitive function is causal, prevention of oral diseases is crucial for a better quality of life.”
No conflicts of interest were disclosed.
