Michael G McGrady

The association between social deprivation and the prevalence and severity of dental caries and fluorosis in populations with and without water fluoridation

BackgroundTo determine the association between social deprivation and the prevalence of caries (including caries lesions restricted to enamel) and enamel fluorosis in areas that are served by either fluoridated or non-fluoridated drinking water using clinical scoring, remote blinded, photographic scoring for caries and fluorosis. The study also aimed to explore the use of remote, blinded methodologies to minimize the effect of examiner bias.MethodsSubjects were male and female lifetime residents aged 11–13 years. Clinical assessments of caries and fluorosis were performed on permanent teeth using ICDAS and blind scoring of standardized photographs of maxillary central incisors using TF Index (with cases for fluorosis defined as TF > 0).ResultsData from 1783 subjects were available (910 Newcastle, 873 Manchester). Levels of material deprivation (Index of Multiple Deprivation) were comparable for both populations (Newcastle mean 35.22, range 2.77-78.85; Manchester mean 37.04, range 1.84-84.02). Subjects in the fluoridated population had significantly less caries experience than the non-fluoridated population when assessed by clinical scores or photographic scores across all quintiles of deprivation for white spot lesions: Newcastle mean DMFT 2.94 (clinical); 2.51 (photo), Manchester mean DMFT 4.48 (clinical); 3.44 (photo) and caries into dentine (Newcastle Mean DMFT 0.65 (clinical); 0.58 (photo), Manchester mean DMFT 1.07 (clinical); 0.98 (photo). The only exception being for the least deprived quintile for caries into dentine where there were no significant differences between the cities: Newcastle mean DMFT 0.38 (clinical); 0.36 (photo), Manchester mean DMFT 0.45 (clinical); 0.39 (photo). The odds ratio for white spot caries experience (or worse) in Manchester was 1.9 relative to Newcastle. The odds ratio for caries into dentine in Manchester was 1.8 relative to Newcastle. The odds ratio for developing fluorosis in Newcastle was 3.3 relative to Manchester.ConclusionsWater fluoridation appears to reduce the social class gradient between deprivation and caries experience when considering caries into dentine. However, this was associated with an increased risk of developing mild fluorosis. The use of intra-oral cameras and remote scoring of photographs for caries demonstrated good potential for blinded scoring.

Quantitative Light Fluorescence (QLF) and Polarized White Light (PWL) assessments of dental fluorosis in an epidemiological setting

BackgroundTo determine if a novel dual camera imaging system employing both polarized white light (PWL) and quantitative light induced fluorescence imaging (QLF) is appropriate for measuring enamel fluorosis in an epidemiological setting. The use of remote and objective scoring systems is of importance in fluorosis assessments due to the potential risk of examiner bias using clinical methods.MethodsSubjects were recruited from a panel previously characterized for fluorosis and caries to ensure a range of fluorosis presentation. A total of 164 children, aged 11 years (±1.3) participated following consent. Each child was examined using the novel imaging system, a traditional digital SLR camera, and clinically using the Dean’s and Thylstrup and Fejerskov (TF) Indices on the upper central and lateral incisors. Polarized white light and SLR images were scored for both Dean’s and TF indices by raters and fluorescence images were automatically scored using software.ResultsData from 164 children were available with a good distribution of fluorosis severity. The automated software analysis of QLF images demonstrated significant correlations with the clinical examinations for both Dean’s and TF index. Agreement (measured by weighted Kappa’s) between examiners scoring clinically, from polarized photographs and from SLR images ranged from 0.56 to 0.92.ConclusionsThe study suggests that the use of a digital imaging system to capture images for either automated software analysis, or remote assessment by raters is suitable for epidemiological work. The use of recorded images enables study archiving, assessment by multiple examiners, remote assessment and objectivity due to the blinding of subject status.

Dental fluorosis in populations from Chiang Mai, Thailand with different fluoride exposures – Paper 1: assessing fluorosis risk, predictors of fluorosis and the potential role of food preparation

BackgroundTo determine the severity of dental fluorosis in selected populations in Chiang Mai, Thailand with different exposures to fluoride and to explore possible risk indicators for dental fluorosis.MethodsSubjects were male and female lifetime residents aged 8–13 years. For each child the fluoride content of drinking and cooking water samples were assessed. Digital images were taken of the maxillary central incisors for later blind scoring for TF index (10% repeat scores). Interview data explored previous cooking and drinking water use, exposure to fluoride, infant feeding patterns and oral hygiene practices.ResultsData from 560 subjects were available for analysis (298 M, 262 F). A weighted kappa of 0.80 was obtained for repeat photographic scores. The prevalence of fluorosis (TF 3+) for subjects consuming drinking and cooking water with a fluoride concentration of <0.9 ppm was 10.2%. For subjects consuming drinking and cooking water >0.9 ppm F the prevalence of fluorosis (TF 3+) rose to 37.3%. Drinking and cooking water at age 3, water used for infant formula and water used for preparing infant food all demonstrated an increase in fluorosis severity with increase in water fluoride level (p < 0.001). The probability estimate for the presentation of aesthetically significant fluorosis was 0.53 for exposure to high fluoride drinking (≥0.9 ppm) and cooking water (≥1.6 ppm).ConclusionsThe consumption of drinking water with fluoride content >0.9 ppm and use of cooking water with fluoride content >1.6 ppm were associated with an increased risk of aesthetically significant dental fluorosis. Fluoride levels in the current drinking and cooking water sources were strongly correlated with fluorosis severity. Further work is needed to explore fluorosis risk in relation to total fluoride intake from all sources including food preparation.

Evaluating the use of fluorescent imaging for the quantification of dental fluorosis

BackgroundThe quantification of fluorosis using fluorescence imaging (QLF) hardware and stain analysis software has been demonstrated in selected populations with good correlation between fluorescent image metrics and TF Index scores from photographs. The aim of this study was to evaluate the ability of QLF to quantify fluorosis in a population of subjects (aged 11–13) participating in an epidemiological caries and fluorosis survey in fluoridated and non-fluoridated communities in Northern England.MethodsFluorescent images of the maxillary incisors were captured together with standardized photographs were scored blind for fluorosis using the TF Index. Subjects were excluded from the analysis if there were restorations or caries on the maxillary central incisors.ResultsData were available for 1774 subjects (n=905 Newcastle, n=869 Manchester). The data from the fluorescence method demonstrated a significant correlation with TF Index scores from photographs (Kendall’s tau = 0.332 p<0.0001). However, a number of additional confounding factors such as the presence of extrinsic stain or increased enamel translucency on some subjects without fluorosis or at low levels of fluorosis severity had an adverse impact on tooth fluorescence and hence the outcome variable. This in conjunction with an uneven distribution of subjects across the range of fluorosis presentations may have resulted in the lower than anticipated correlations between the fluorescent imaging metrics and the photographic fluorosis scores. Nevertheless, the fluorescence imaging technique was able to discriminate between a fluoridated and non-fluoridated population (p<0.001).ConclusionsDespite confounding factors the fluorescence imaging system may provide a useful objective, blinded system for the assessment of enamel fluorosis when used adjunctively with photographic scoring.

Adolescents' perceptions of the aesthetic impact of dental fluorosis vs. other dental conditions in areas with and without water fluoridation

BackgroundThe use of fluorides for caries prevention is well established but is linked with an increased risk of dental fluorosis, some of which may be considered to be aesthetically objectionable. Patient opinion should be considered when determining impact on aesthetics. The aim of this study was to assess participant rating of dental aesthetics (from photographic images) of 11 to 13 year olds participating in an epidemiological caries and fluorosis survey in a fluoridated and a non-fluoridated community in Northern England.MethodsConsented participants were invited to rank in order of preference (appearance) a collage of 10 computer generated images on a touch-screen laptop. The images comprised an assortment of presentations of teeth that included white teeth, a spectrum of developmental defects of enamel and dental caries. Data were captured directly and exported into SPSS for analysis.ResultsData were available for 1553 participants. In general, there were no significant differences in the rank positions between the fluoridated and non-fluoridated communities, with the exception of teeth with caries and teeth with large demarcated opacities. Very white teeth had the highest rating in both localities. Overall, there was a trend for teeth with fluorosis to be ranked more favourably in the fluoridated community; for TF 1 and TF 2 this preference was significant (p < 0.001).ConclusionsThe results of this study suggest teeth that are uniformly very white have the highest preference. The rankings suggest teeth with a fluorosis score of TF 1 may not be considered aesthetically objectionable to this population and age group. The image depicting a tooth with caries and the image with large demarcated opacities were deemed to be the least favoured. Participant preference of images depicting fluorosis falls with increasing severity of fluorosis.

Dental fluorosis in populations from Chiang Mai, Thailand with different fluoride exposures - Paper 2: The ability of fluorescence imaging to detect differences in fluorosis prevalence and severity for different fluoride intakes from water

BackgroundTo assess the ability of fluorescence imaging to detect a dose response relationship between fluorosis severity and different levels of fluoride in water supplies compared to remote photographic scoring in selected populations participating in an observational, epidemiological survey in Chiang Mai, Thailand.MethodsSubjects were male and female lifetime residents aged 8-13 years. For each child the fluoride content of cooking water samples (CWS) was assessed to create categorical intervals of water fluoride concentration. Fluorescence images were taken of the maxillary central incisors and analyzed for dental fluorosis using two different software techniques. Output metrics for the fluorescence imaging techniques were compared to TF scores from blinded photographic scores obtained from the survey.ResultsData from 553 subjects were available. Both software analysis techniques demonstrated significant correlations with the photographic scores. The metrics for area effected by fluorosis and the overall fluorescence loss had the strongest association with the photographic TF score (Spearman’s rho 0.664 and 0.652 respectively). Both software techniques performed well for comparison of repeat fluorescence images with ICC values of 0.95 and 0.85 respectively.ConclusionsThis study supports the potential use of fluorescence imaging for the objective quantification of dental fluorosis. Fluorescence imaging was able to discriminate between populations with different fluoride exposures on a comparable level to remote photographic scoring with acceptable levels of repeatability.

Sugar before bed: a simple dietary risk factor for caries experience

Clinical care pathways have placed renewed emphasis on caries risk assessment and the ability to predict and prevent further disease. With diet considered a key factor in the development of caries, the level of caries risk posed by dietary habits, such as the frequency of intake and timing of free sugars is questioned. OBJECTIVE To identify reliable and simple dietary risk factors for caries experience. RESEARCH DESIGN A cross-sectional observational study of a convenience sample with data gained from clinical examinations, questionnaire and a 24 hour dietary-recall interview. PARTICIPANTS 128 subjects aged 11-12 from comprehensive schools in Greater Manchester and Newcastle upon-Tyne, UK. OUTCOME MEASURES free sugars consumed between meals, before bed and total % of total free sugars consumed were assessed from dietary assessments led by a dietitian. D4-6MFT was generated with a caries threshold of ICDAS stage 4 from clinical examinations. RESULTS Analysis revealed no significant differences in caries experience when looking specifically at caries into dentine, referred to as the cavity group (split at D4-6MFT), between high and low deprivation, consumption of free sugars between meals and free sugars (%). The consumption of free sugars within the hour before bed revealed a statistically significant difference between the cavity/no cavity groups (p=0.002). Logistic regression analysis on the cavity/no cavity groups revealed an odds ratio of 2.4 (95%CI 1.3,4.4) for free sugars consumption before bedtime. CONCLUSIONS The study suggests that the consumption of free sugars before bedtime may be an important risk factor for adolescent caries into dentine experience.

Prevalence and severity of dental fluorosis in four English cities

Objective To assess the prevalence and severity of dental fluorosis in four city-based populations using a robust photographic method with TF index reporting; and to record the aesthetic satisfaction scores of children in all four cities. Basic research design Cross sectional epidemiological survey (surveillance). Participants 1,904 children aged 11-14 years, in four English cities. Interventions Two cities were served by community water fluoridation schemes supplying water at 1mg/l F. The other two cities did not have water fluoridation schemes and had low levels of fluoride naturally present. Main outcome measures The prevalence and severity of dental fluorosis. Scoring was undertaken using high quality digital images by a single calibrated examiner. Results Data suggest that the prevalence of fluorosis at levels greater than TF2 are broadly similar to previous studies (F 10%, NF 2%), with an apparent increase in the total number of TF1 cases across both fluoridated (41%) and non-fluoridated cities (32%) with a commensurate decrease in TF0 (F 39%, NF 63%). Data suggest that the proportion of children expressing dissatisfaction with the appearance of their teeth is the same in fluoridated and non-fluoridated communities although the reasons for this may differ. Conclusions The levels of fluorosis that might be considered of aesthetic concern are low and stable while the increase in TF1 may be due to an increase in self- and professionally-applied fluoride products or the increased sensitivity afforded by the digital imaging system. It is not however a public health problem or concern. Further monitoring appears justified.

Automatic detection and classification of dental fluorosis in vivo using white light and fluorescence imaging

OBJECTIVES To assess a novel method of automatic fluorosis detection and classification from white light and fluorescent images. METHODS Dental images from 1,729 children living in two fluoridated and two non-fluoridated UK cities were utilised. A novel detection and classification algorithm was applied to each image and TF scores were obtained using thresholding criteria. These were compared to clinical reference standard images. Comparisons between reference and automated assessments were undertaken to record correct and incorrect classifications and the ability of the system to separate the fluoridated and non-fluoridated populations. RESULTS The automated system performed well and was able to differentiate the two populations (P < 0.0001) to the same degree as the reference standard. When using the highest score from the clinical assessment the agreement between automated and clinical assessments was 0.56 (Kappa SE = 0.0160, p < 0.0001). CONCLUSIONS Assessment of dental fluorosis is typically undertaken by clinical examiners in epidemiological studies. The training and calibration of such examiners is complex and time consuming and the assessments are subject to bias - frequently because of the examiners awareness of the water fluoridation status of subjects. The use of remote scoring using photographs has been advocated but still requires trained examiners. This study has shown that image-processing methodologies applied to white light and fluorescent images could automatically score fluorosis and statistically separate fluoridated and non-fluoridated areas. The system requires further refinement to manage confounding factors such as the presence of non-fluoride opacities and tooth stain.

NHS Health Checks in a primary care dental setting – an opportunity for the profession to maximise uptake for public health partners?

This opinion piece considers an opportunity for primary dental care practitioners to work in partnership with public health teams to maximise the uptake of the NHS Health Check. Public Health England and Local Authority partners remain committed to offering the NHS Health Check to those aged 40–74 years old. The programme previously explored alternative points of delivery – such as community pharmacists. This piece discusses and reflects on the efforts within Manchester to use skill mix in primary dental care services and widen access to target individuals eligible for an NHS Health Check. The pilot schemes in Manchester illustrated the willingness and enthusiasm for primary care dentists to embrace change and work alongside new partners to deliver patient benefit beyond the provision of dental care. However, substantial barriers to implementation prevented the desired level of progress.