• Abdullah Bin Rahmah

Student thesis: Phd


Abstract Background: Oral health is one part of general health and wellbeing that plays an essential role in developing a healthy child. Dental caries is the most common chronic oral disease globally. Caries in childhood has been linked to socioeconomic status across the social gradient, with widening oral health disparities between those at the bottom and top of the socioeconomic scale. Deprivation in childhood is associated with a higher prevalence of dental caries that lasts through adulthood. The dental health of children in England has improved. However, dental caries continues to affect a subgroup of children characterised by a low SES, such as deprivation. This has consequences for the individual and society in future. Aims: 1) To systematically review studies which explicitly assess the association between level of deprivation and prevalence and severity of dental caries in children in the United Kingdom. 2) A systematic review to provide an in-depth appraisal of the use of causal analysis in observational studies like structural equation modelling in dental caries research. 3) To investigate the factors influencing adolescents' dental caries using structural equation modelling (SEM) to identify behavioural, biological and environmental mediators of the relationship between deprivation status and dental caries.. 4) To systematically review the evidence of the effects of water fluoridation on dental caries, specifically in relation to health disparities. Methods: 1) The studies that explored the relationship between deprivation and dental caries were assessed using the Newcastle-Ottawa Scale for observational studies and the Cochrane Risk of Bias Assessment tool for randomised controlled trials. 2) A systematic review was conducted to identify and appraise studies that have used SEM and provide an outline of the basic SEM concept, including methods to identify the research problem and the model for evaluation, methods used to estimate the model coefficients and model fit and to consider more broadly the application of SEM in dental caries research. 3) Two structural equation models were developed to investigate the direct and indirect relationships between deprivation, oral health behaviour (including night eating, frequency of tooth brushing and rinsing after tooth brushing), dental attendance, plaque accumulation, dental preventive program and dental caries experience. 4) A systematic review using the Cochrane methodology was conducted in order 8 to determine the effects of community water fluoridation on reducing disparities in dental caries across population subgroups. Results: 1) The studies presented evidence of how different dental health experiences vary among the affluent and deprived. 2) SEM holds several opportunities. Despite its potential as a statistical research tool, SEM has only been used in a limited number of studies in dental caries research. 3) In both models: adolescents living in the most deprived areas had significant negative estimates of oral health behaviour. Also, dental caries and plaque accumulation were significantly associated with oral health behaviours, respectively. The total indirect effect of adolescents living in the most deprived areas was significant. In Model 2: the indirect effect of oral health behaviour in the association between deprivation and dental caries was significant. 4) There is insufficient information to infer whether initiation of a water fluoridation programme results in a change in disparities in caries levels across different segments of the population. Moreover, despite the limitations of our review, the existing evidence points to an increase in caries rates following stopping water fluoridation programmes. Conclusions:The overall findings of this thesis confirm that deprivation measures' dimensional segments are likely to determine the beneficial influences on oral health promotion planning processes. The evidence on the relationship between deprivation and d
Date of Award1 Aug 2022
Original languageEnglish
Awarding Institution
  • The University of Manchester
SupervisorAlison Qualtrough (Supervisor), Tanya Walsh (Supervisor) & Anne-Marie Glenny (Supervisor)

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