AffiliationFaculty of Education, Health and Wellbeing
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AbstractIntroduction: Dementia and oral diseases are two major public health problems in the world. There has been growing interest in examining their associations for disease prevention and health care. A few studies suggested that the association could be bidirectional, but the evidence is still inconclusive. This PhD study aimed to comprehensively assess whether poor oral health increased the risk of dementia while people with dementia had increased oral diseases regardless of other factors. Methods: A mixed method of quantitative and qualitative approaches was employed, including meta-analysis from literature, analysing the data of a hospital-based case-control study and a population-based cohort study (i.e., English longitudinal study of ageing [ELSA]) and running three focus groups. The case-control study was carried out in Guangzhou, China, interviewing 233 patients with dementia and 233 controls without dementia. ELSA dataset included the participants from wave 3 (2006-07) to wave 9 (2018-19), each wave having around 9,800 participants and recording dementia and oral health problems. In standard methods of interview, the participants in the case-control study and ELSA had documented the data of demographics, lifestyles, cardiovascular risk factors, oral health and other disease risk factors. The associations between dementia and oral health problems were analysed in multivariate-adjusted logistic regression models. The three focus groups included 17 caregivers of people with dementia in Wolverhampton, UK, and their data were examined using thematic analysis. Findings: Both the case-control study and ELSA cohort study showed a significant association of poor oral health with dementia; multiple adjusted odds ratio (OR) of dementia in poor self-rated oral health (SROH) was 1.97 (95%CI 1.01-3.85) and 1.93 (1.00-3.72) respectively. The case-control study also demonstrated increased ORs of dementia in periodontal disease (PD) (OR 1.92, 95%CI 1.17-3.17) in no teeth (6.51, 2.47-17.15) and in other indicators of poor oral health. ELSA further found a non-significant increased OR of incident dementia in those oral impact variables. In examining the association of dementia with poor oral health, the case-control study, where 17.6% of participants reported poor SROH, 55.6% fair, and 26.8% good, showed a non-significantly increased OR of poor SROH in patients with dementia, but significantly increased ORs of moderate/severe PD, the number of teeth and less oral care. The ELSA study showed that dementia was not significantly associated with incident poor SROH; however, combined data of dementia and severe cognitive impairment (SCI) suggested a significant OR of incident poor SROH (1.90, 1.22-2.98) although increased ORs of the total score of oral impacts and edentulism were not significant. The overall quality of identified studies was good. In the meta-analysis, pooled data from ten studies showed an overall significant association of PD with dementia [relative risk (RR) 1.43, 95%CI 1.15-1.79] and the pooled RR from six studies for dementia and cognitive impairment was 1.54 (1.18-2.01). The data from the focus group supported the findings of quantitative studies by their theme relation, care and external factors. Conclusions: This PhD research has suggested that poor oral health may increase the risk of dementia, and people with dementia or SCI could increase the risk of poor oral health. Maintaining oral hygiene and care in people with dementia or SCI is needed to ensure a better quality of life in older people, while keeping good oral health in the general population would help reduce the incidence of dementia worldwide.
CitationNadim, R. (2022) Association between oral health and dementia. Wolverhampton: University of Wolverhampton. http://hdl.handle.net/2436/625043
PublisherUniversity of Wolverhampton
TypeThesis or dissertation
DescriptionA thesis submitted in partial fulfilment of the requirements of the University of Wolverhampton for the degree of Doctor of Philosophy.
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