Oral Health Services Research Centre - Doctoral Theses

Permanent URI for this collection


Recent Submissions

Now showing 1 - 5 of 6
  • Item
    Impact of downward adjustment of water fluoride concentration on dental caries and fluorosis
    (University College Cork, 2022-12-20) James, Patrice; Whelton, Helen; Harding, Mairead; O’Mullane, Denis; Perry, Ivan J.; Cronin, Michael; Health Research Board
    Introduction: Community water fluoridation (CWF) was initiated in Ireland in 1964 at a concentration of 0.8 to 1 ppm fluoride. In 2007, in the context of ongoing reductions in dental caries with increasing prevalence and severity of dental fluorosis, water fluoride concentration in Ireland was adjusted to 0.6 to 0.8 ppm with the aim of reducing the prevalence and severity of dental fluorosis while maintaining reductions in dental caries. Aim: To determine the difference in dental caries and fluorosis levels following downward adjustment of CWF concentration. Methods: Ethical approval was obtained from the Clinical Research Ethics Committee (CREC) of the Cork Teaching Hospitals. A before and after study compared dental caries and fluorosis in random samples of 8-year-olds in Dublin (n=707) and Cork-Kerry (n=1,148) in 2016-17 with 8-year-olds in Dublin (n=679) and Cork-Kerry (n=565) in 2002. Dentinal caries experience in primary teeth (d3vcmft(cde)) and fluorosis in permanent teeth (Dean’s Index, whole mouth score) were clinically measured by trained and calibrated dentists. Standardised oral photographs were taken (8 seconds drying) for children in Cork-Kerry in 2016-17 and 2002. Fluorosis (Thylstrup-Fejerskov (TF) Index) in permanent maxillary central incisors was scored from the photographs in duplicate by two trained and calibrated dentists, blind to fluoridation status and year, with disagreements resolved by consensus. Person-level TF score was the highest score in the central incisors. Children were categorised as having lifetime or no exposure to CWF (Full-CWF/No-CWF). Effect of examination year on dental caries prevalence (d3vcmft(cde) > 0) and severity (mean d3vcmft(cde) among children with caries experience) and fluorosis prevalence (Dean’s ‘very mild’ or greater, TF 1 or greater and TF 2 or greater) were evaluated using multivariable regression controlling for the effects of other explanatory variables. Additional multivariable regression analyses evaluated the effect of CWF on dental caries prevalence and severity and fluorosis prevalence in 2002 and 2016-17, before and after the downward adjustment, respectively. Results: After controlling for the effects of other explanatory variables, children in Cork-Kerry in 2016-17, with lifetime exposure to CWF at 0.6 to 0.8 ppm fluoride, had lower caries prevalence (56% vs. 65%) and severity (mean d3vcmft(cde) 3.7 vs. 4.2) in primary teeth than their counterparts with No-CWF. Among children with Full-CWF, there was no statistically significant difference in caries prevalence or severity between 2002 and 2016-17. In 2016-17, caries prevalence was 55% in Dublin (Full-CWF) and 56% in Cork-Kerry (Full-CWF) and mean d3vcmft(cde) among children with caries was 3.4 and 3.7, respectively. Among children with No-CWF, caries severity was less in 2016-17 (mean 4.2) than 2002 (mean 4.9) (P = 0.039). The difference in caries severity between children with Full-CWF and No-CWF was less in 2016-17 than 2002 (Interaction P = 0.013), suggesting a reduced benefit for CWF in 2016-17. In 2016-17, fluorosis prevalence (Dean’s Index) was 18% in Dublin (Full-CWF) and 12% in Cork-Kerry (Full-CWF). Fluorosis was predominantly ‘very mild’ with no statistically significant difference between 2002 and 2016-17. Fluorosis prevalence in permanent maxillary central incisors was predominantly TF 1 and TF 2 and was lower in Cork-Kerry in 2016-17 than in 2002 at both case definitions. Among children with Full-CWF, prevalence of TF 1 or greater was 40% in 2016-17 and 75% in 2002 (OR 0.24, 95% CI [0.17, 0.34], P < 0.001) and prevalence of TF 2 or greater was 15% in 2016-17 and 27% in 2002 (OR 0.50, 95% CI [0.33, 0.75], P = 0.001). At both time points, fluorosis prevalence measured using Dean’s Index and the TF Index was higher among children with Full-CWF than their counterparts with No-CWF (2002 and 2016-17, P < 0.001). Conclusion: There was no reduction in fluorosis prevalence measured clinically using Dean’s Index in 2016-17 compared with 2002. However, fluorosis prevalence in the aesthetically important maxillary central incisors measured blind to year and fluoridation status from oral photographs was reduced following downward adjustment of water fluoride concentration. Based on the cross-sectional comparison of children with Full-CWF and No-CWF in 2016-17, the lower concentration of 0.6 to 0.8 ppm fluoride is an effective caries-preventive measure. However, the before and after study indicated that downward adjustment of water fluoride concentration may have reduced the caries-preventive effect of CWF in primary teeth. Further research is needed to evaluate the impact of the downward adjustment on dental caries in permanent teeth of children and adults with CWF.
  • Item
    Children and adolescents and modified twin block for Class II division 1 malocclusion compared to controls: quantitative and qualitative analyses
    (University College Cork, 2021-07) O'Dwyer, Caroline; Millett, Declan
    Aims • To evaluate the impact Modified Twin Block (MTB) treatment has on oral health related quality of life (OHRQoL), self-esteem, self-perception of aesthetic treatment need and 3D soft tissue facial changes in children with Class II division 1 malocclusion (II/1M) compared to children with II/1M awaiting treatment who served as controls. • To assess the effect MTB treatment has on family quality of life (QoL) and on both the parent’s perception of their child’s OHRQoL and aesthetic treatment need compared to controls. • To assess the level of agreement of child OHRQoL and perception of aesthetic treatment need by child and parent between groups. Materials and methods Following ethical approval, 60 subjects (31 males; 29 females) received MTB treatment (MTB group) and 47 subjects (22 males; 25 females) with II/1M awaiting treatment served as controls (Control group). At baseline (T1) and following MTB treatment/recall (T2) all subjects completed the Child Perception Questionnaire (CPQ11-14), Child Health Questionnaire short from (CHQ-CF45) and self-assessed aesthetic treatment need (IOTN-AC). Each child also had a 3D facial image captured at rest. At the same time points, a parent of each child completed the Parent-Caregiver Perception Questionnaire (P-CPQ) and assessed their child’s aesthetic treatment need (IOTN-AC). Comparisons of patient demographics were made using ANOVA and Chi-square tests. ANOVA was used for comparisons in CPQ, P-CPQ, CHQ-CF45 and 3D soft tissue facial changes at T1 and T2 between groups and paired t-tests were used within both groups. Bowker’s symmetry test was used to compare IOTN-AC within groups and Fisher’s Exact test was used between groups. ANOVA was used to test for associations between CPQ, CHQ, IOTN-AC, and 3D soft tissue facial change. Results Forty-two subjects (20 males; 22 females) completed MTB treatment (average duration 8.5 months; range 5-12 months) and 35 untreated II/1M subjects (15 males; 20 females) were recalled after an average time of 11 months (range 9-13 months). At T1, groups were similar in age (p=0.1402) and gender (p=0.2973) but overjet in the MTB group was slightly greater (p=0.0016). At T2, there was a significant improvement in the MTB group in overall OHRQoL (p<0.0001) and self-perception of aesthetic treatment need (p=0.018) but there was no change in self-esteem (p=0.144). Significant improvements occurred in family QoL (p=0.0001), in parent’s perception of both their child’s OHRQoL (p<0.0001) and aesthetic treatment need (p<0.0001). In the MTB and Control groups and at both time points, the level of agreement between child and parent perception of the child’s OHRQoL was poor with parents rating it worse [MTB group T1, p=0.0001; T2, p=0.003]; [Control group T1, p=0.001; T2, p=0.008]. At T1, parents rated the aesthetic treatment need to be greater than their child in the MTB group (p=0.054) and Control group (p=0.04). At T2, the level of agreement between the child and parent in their aesthetic treatment need was similar (p=0.262) but in the MTB group children perceived their aesthetic treatment need to be greater than their parents (p=0.019). From T1 to T2, significant 3D soft tissue changes occurred at Pogonion in the MTB group 4.26 mm (p= 0.001) and in the Control group 3.29 mm (p=0.002) but the mean difference between the groups (0.97 mm; p=0.011) was not clinically significant. Conclusions • MTB treatment significantly improved the OHRQoL and self-perception of aesthetic treatment need in children with II/1M but had no significant impact on self-esteem or 3D soft tissue facial changes compared to controls. • MTB treatment significantly improved the family QoL and both the parent’s perception of their child’s OHRQoL and aesthetic treatment need compared to controls. • In children following MTB treatment or awaiting treatment, poor agreement existed between the child and parent perception of OHRQoL and aesthetic treatment need.
  • Item
    Adolescent and parent perceptions of expected benefits of orthodontic treatment: a mixed-methods study
    (University College Cork, 2021-06-30) Smyth, Joshua Peter Richard; Millett, Declan
    Aims: 1: To investigate expected benefits of orthodontic treatment from both an adolescent and parent perspective. 2: To rank the expected benefits of orthodontic treatment identified by adolescents and parents in order of perceived importance. Materials and Methods: Ethical approval was granted to carry out both parts of this study. Part 1 used qualitative methodology with one-to-one semi-structured interviews by a trained interviewer. Twenty adolescents (10 males; 10 females) referred for orthodontic assessment and their parents (8 males; 12 females) were interviewed independently to explore expectations of the benefits of orthodontic treatment. Interviews were transcribed verbatim and interpretive phenomenological analysis carried out. Part 2 quantitatively assessed the benefits identified in Part 1. Twelve additional adolescents (6 males; 6 females) who were referred for orthodontic assessment and a parent (6 males; 6 females), completed a card ranking exercise to determine the rank order of the perceived importance of each benefit. The mean rank was then calculated and a two-sample t-test, with the level of significance set at P < 0.05, used to determine if a difference existed between adolescents and parents for the mean rank of any of the expected benefits. Results: The expected benefits of orthodontic treatment from both adolescent and parent perspectives included 11 benefits which could be grouped into four categories: oral health (improved appearance of teeth; ease of maintaining good oral health; improved jaw alignment; aiding dental development), psychosocial (improved self-confidence; improved perception of dental appearance by others), functional (improved ability to chew food; improved speech) and behavioural change (improved oral hygiene habits; improved diet; cessation of bad habits). Adolescents and parents placed a similar level of importance on these benefits with “improved self-confidence” ranked highest and “improved speech” ranked lowest. The only benefit where the mean rank differed significantly between adolescents and parents was “improved ability to chew food” (two-sample t-test; P = 0.042) which was ranked higher by adolescents. Conclusions: Adolescents and parents perceived 11 expected benefits from orthodontic treatment affecting oral health, psycho-social, functional and behavioural categories. Adolescents and parents ranked the expected benefits similarly with psycho-social ranked highest. Within functional benefits, speech improvement was ranked lowest by both but improved masticatory function was ranked of significantly greater importance by adolescents.
  • Item
    Incidence of hypoxaemia with intravenous fentanyl and midazolam sedation in adult patients undergoing oral surgery procedures
    (University College Cork, 2021-08-03) Mooney, Eimear; Brady, Paul
    Objectives: Respiratory depression and airway compromise may result in serious consequences if untreated during conscious sedation. The primary aim of this study was to investigate the incidence of hypoxaemia (SpO2 ≤94%) in American Society of Anaesthesiologists physical status I & II patients undergoing intravenous sedation with fentanyl and midazolam. The secondary aims included determination of the onset time of hypoxaemic events and significant risk factors for hypoxaemia. Methods: This prospective observational study required 92 patients to achieve a power of 80% at the 5% significance level. A total of 96 patients, (57 female, aged 16-65) met the inclusion criteria and consented to participation. The operator-sedationist delivered a standard dose of 50μg of fentanyl followed by titrated midazolam (range 2-9mg), at a rate no greater than 1mg/min. Oxygen saturations were monitored via pulse oximetry and supplemental oxygen was not given routinely, unless indicated. Verbal or tactile stimulation was performed to encourage respiratory effort when SpO2 ≤94%. Monitoring continued for forty minutes from the time of sedation end point. Data were exported from the ‘BeneVision N12 Mindray’ monitor to Microsoft Excel. Statistical analyses (multi-variate logistical regression) were performed in SAS® (Version 9.4). Results: All participants successfully completed treatment and 94 patients were included in the analysis. 50 (53%) individuals developed hypoxaemia, with 19 (20%) proceeding to severe hypoxaemia (SpO2<90%). Following administration of fentanyl, 90% of hypoxaemic events occurred within 13.6 minutes; the majority (66%) were observed during the pre-operative period. The risk of hypoxaemia increased for each 1% reduction in SpO2 and 1kPa reduction in EtCO2 from baseline by 190% and 192%, respectively. The risk of moderate and severe hypoxaemia increased by 7% (p=0.0003) & 8% (p = 0.0002) respectively, for each added year of age. Conclusions: This study presents information on the incidence of hypoxaemia for multidrug sedation in ASA I & II patients in an outpatient oral surgery department. Whilst the hypoxaemia incidence was found to be 53%, all patients remained responsive to respiratory stimulation, consistent with the definition of conscious sedation. Heightened vigilance for desaturation is required for reductions in SpO2 and EtCO2 from baseline within the first 13.6 minutes following fentanyl administration and with advancing age.
  • Item
    Personalised dental education for caries risk reduction in an adult population in the Republic of Ireland
    (University College Cork, 2018) Nishi, Makiko; Allen, P. Finbarr; Whelton, Helen; Harding, Mairead; International Association for Dental Research; Unilever
    Overall aim: To investigate the impact on caries risk reduction of a personalised dental education approach based on individual caries risk assessment using mobile-phone short text messages in an economically disadvantaged adult population in the Republic of Ireland. Methods: Two studies were conducted: a cross-sectional study with patients recruited through a non-profit organisation in Japan using questionnaires, and a 2-arm parallel-group, single-blinded, randomised controlled study with medical-card holders recruited in Ireland; caries risk was assessed using the Cariogram and participants responded to a survey questionnaire. Results: A higher proportion of Irish participants (n = 159) identified “Not visiting the dentist for check-up and cleaning” (odds ratio (OR) 2.655; 99% confidence interval (CI) 1.550, 4.547) and “Not using fluoride” (OR 1.714; 99% CI 1.049, 2.802) than did Japanese participants (n =482) as caries risk factors. There was an association between assessed caries risk (Chance-AC) and self-perceived caries risk in the four risk groups (n = 165). Approximately two-thirds of participants in the high-risk groups did not consider themselves as being more prone to dental decay than the average person. Caries risk profiles among participants (n = 167) were clustered into five groups. As a result of protocol violations, 84% of the 111 participants (56: personalised group; 55: non-personalised group) were not sent their assigned number and combination of text messages. Intent-to-treat analysis did not show a personalised intervention effect in Chance-AC. Of the secondary outcome measures, the stimulated saliva amount factor showed a personalised intervention effect, P = 0.036 (OR 0.3; 95% CI 0.1, 0.9). Conclusions: This thesis could not reach a definitive conclusion as to whether a personalised mHealth approach was more effective than a non-personalised mHealth approach, the exception being for the saliva amount parameter. It is worth further exploring the potential of mobile-devices for personalised caries risk reduction.