Levels Of Fluorosis Research Articles

One-in-a-million; the first community trial of water fluoridation

During the 1930s and early 1940s, H Trendley Dean and his colleagues working from the US National Institutes of Health published a series of epidemiological studies describing the relationship between the level of fluoride naturally present in public drinking-waters and the prevalence and severity of dental fluorosis (1) and dental caries. (2) Dental fluorosis is a white--and in more severe cases an unsightly brown--developmental defect of dental enamel, while dental caries is a post-eruptive disease of the teeth caused by the action of certain oral bacteria on ingested dietary sugars. As the natural fluoride level rises from low levels (less than 0.1 mg/1), so the prevalence and severity of dental fluorosis increase while the extent of dental caries--usually summarized by the index of the mean number of decayed, missing and filled teeth (DMFT)--falls. Dean and his colleagues (3) suggested that in temperate climates and at a fluoride concentration in drinking-water of around 1 mg/l, the level of dental caries was substantially less than that associated with low levels of fluoride, while the level of dental fluorosis had increased but only to a level that was clinically and aesthetically of concern. Furthermore, in parallel studies significant other health effects could be seen in areas with fluoride levels in public drinking-water even as high as 8 mg/l. For example, a study in Bartlett, Texas, (4) reported on potential health effects in people with long-term residence of at least 15 years who consumed public water with a natural fluoride level of 8 mg/l, compared with long-term residents of nearby Cameron where the fluoride level was 0.4 mg/1. Ibis study, involving a medical history, physical and dental examinations, X-ray, and blood and urine analyses, was conducted in 1943 and repeated in 1953. For the important bone changes the study reported that only 10-15% of humans who consumed a water supply with an excessive fluoride content (8 mg/l) for a long time may show radiographic (but not clinical) evidence of bone changes. The authors concluded: no clinically significant physiological or functional effects resulted from prolonged ingestion of water containing excessive fluoride except for dental fluorosis. In the light of these and similar studies it was not surprising that a hypothesis was formulated that the adjustment of the fluoride level of public drinking-water supplies to 1 mg/1 might have similar effects to naturally fluoridated water. To test this, a controlled community water fluoridation trial in the city of Grand Rapids started on 25 January 1945, with the nearby city of Muskegon acting as a control. Although this was the first water fluoridation trial, at least three other trials were established in the United States and Canada within the next year or so. The first dental data from the Grand Rapids--Muskegon study were published in 1950 (5) and reported baseline data collected in 1944-45 based on examinations of all 28 614 children in Grand Rapids and all 7786 children in Muskegon aged 4-16 years, together with follow-up data collected in 1949. Annual examination of selected samples of children continuously resident in Grand Rapids continued for 15 years. Muskegon remained the non-fluoridated control city until July 1951, at which time, in response to the observed effects in Grand Rapids, city officials decided to fluoridate the supply in Muskegon also. Annual dental examinations of samples of children continuously resident continued for a further three years in Muskegon and provided some of the data in the 1956 report by Arnold et al., (6) extracts of which are reproduced below. The authors presented age-specific data for children aged 4-13 years for deciduous teeth and 6-16 years for permanent teeth and noted that water fluoridation was remarkably effective in reducing the incidence of dental caries in both groups. Data for Grand Rapids after 15 years of fluoridation were published by Arnold et al. …

Fluoridation of the public water supply and prevalence of dental fluorosis in a peripheral district of the municipality of Bauru, SP.

Objectives:The objectives of this study were to assess the fluoride concentration in the public water supply and the prevalence of dental fluorosis in schoolchildren between 7 and 15 years old, living in a peripheral district of the municipality of Bauru.Material and Methods:For this, fifty two water samples were collected on three different days of one week. These samples were analyzed for fluoride by means of the ion-sensitive electrode method (Orion 9609) coupled to a potentiometer (Procyon, model 720). In this method, 1.0 mL of TISABII (Orion) was added to 1.0 mL of the sample. For the epidemiological survey of fluorosis, 52 schoolchildren of both genders, aged between 7 and 15 were assessed, with prior authorization from their caretakers. Only one person examined the children, after supervised toothbrushing and drying with cotton wool rolls. The TF index was used.Results:The fluoride concentrations in the water samples ranged from 0.62 to 1.20 mg/L, with a mean of 0.9 mg/L. The prevalence of dental fluorosis was 33%, with severity ranging from TF1 to TF4 (Kappa of 0.73 and concordance of 83.33%).Conclusions:The results from the analysis of water samples indicated a fluoride concentration greater than recommended for Bauru. The fluorosis levels found were higher than expected for a peripheral district, in which water is one of the few sources of fluoride.

An assessment of teenagers’ perceptions of dental fluorosis using digital simulation and web‐based testing

To develop a new model to establish teenagers' perceptions of the aesthetic impact of fluorosis, in the context of overall facial appearance. This web-based model was used to compare different degrees of fluorosis at any one distance, while also comparing the same level of fluorosis at different 'distances'. A 14-year-old subject was used as the model face. Different degrees of fluorosis were 'built-up' on this subject's teeth using digital simulation. A web-based questionnaire showed 30 photographs, displaying four levels of fluorosis, in addition to fluorosis-free, at five different 'distances'. The closest images were shown with and without retractors, while the more distant pictures showed more of the subject's face. Teenage pupils (n = 217) were then asked to grade the acceptability of the appearances and indicate if they would wish treatment for each such appearance. At any one distance, acceptability fell as fluorosis level increased. When the same degree of fluorosis was compared at different distances, acceptability improved as the teeth were viewed from further away. Pictures taken without retractors had higher acceptability than those taken with retractors in place. Teenagers can discriminate between various degrees of fluorosis. However, more distant viewing of fluorosed teeth, within the overall context of the face, improves acceptability of the appearance.

Relationship between dental fluorosis and quality of life: a population based study

The aim of this study was to verify the prevalence of dental fluorosis in schoolchildren aged 6 to 15 and its possible association with the impacts on their daily activities. This study is observational, cross-sectional and analytical. A total of 513 schoolchildren from the city of Pinheiro Preto, SC, took part in this study. The children were examined by three calibrated dentists, after obtaining a kappa > 0.80. To assess the prevalence of fluorosis, clinical examinations were performed according to the methodology set forth by the 4th edition of the WHO. To assess the impact of fluorosis on their daily activities, a modified OIDP (Oral Impacts on Daily Performance) was adopted. The statistical analysis used was the Chi-squared test with a 5% significance level. Of the total number of children examined, 262 (51.1%) were of the female gender and 251 (48.9%) were of the male gender. In regard to the prevalence of fluorosis, 94 (18.3%) of the children presented this condition, while 419 children (81.7%) presented a normal condition. In regard to the severity of fluorosis, few children presented severe alterations. No association was found between dental fluorosis and gender (p = 0.646), between fluorosis and socioeconomic status (p = 0.848) or between fluorosis and access to public water supply system (p = 0.198). The activities that most affected children's daily performance were: oral hygiene (40.9%) and food intake or enjoying food (40.4%). None of the daily activities could be associated with the occurrence of dental fluorosis. The prevalence of dental fluorosis was consonant with the standards found for locations with optimum fluoride content in the water supply. The questionable and very slight levels of fluorosis were the most frequently found, without influence in the quality of life of the schoolchildren participating in the study.

Prevalence of dental fluorosis in children from non-water-fluoridated Halmstad, Sweden: fluoride toothpaste use in infancy

Objectives. To determine the prevalence and severity of dental fluorosis in children aged 7–9 years from non-water-fluoridated Halmstad, Sweden, and to relate the results to their reported fluoride exposure history during infancy. Material and Methods. In Spring 2002, a questionnaire distributed to a cluster random sample of 1039 parents enquired into their child's early oral health behaviors and included a “photographic toothpaste menu”. The permanent upper anterior teeth (13–23) were examined clinically (+10% repeats) using a modified Thylstrup-Fejerskov Index. Results. Complete data were available for 53% (n=548) of the sampled children. The prevalence of fluorosis at any level was 49% (95% CI: 45–54%), and of fluorosis with esthetic concern (TF score ≥3) 4% (95% CI: 3–6%). Based on repeat observations, reliability was good (kappa=0.82). There was no statistically significant increased risk of dental fluorosis prevalence associated with any of the fluoride exposure risk factors examined, including reported usage of (1000 ppm) fluoride toothpaste from time of first deciduous tooth eruption. Conclusions. While there were low levels of dental fluorosis of esthetic concern, half the children had some degree of dental fluorosis. The prevalence of dental fluorosis was not explained by the risk factors, including fluoride toothpaste usage as explored in this study.

Aesthetically objectionable fluorosis in the United Kingdom

A cross-sectional national survey to explore perceptions of dental fluorosis and to determine the proportion of people regarding fluorosis as aesthetically objectionable at differing levels of defect. A survey using a multistage stratified random probability sample of 6,000 UK adult households. Face-to-face interviews were carried out using a structured questionnaire and photographs of different levels of dental fluorosis. Respondents were interviewed about the parameters of satisfaction, attractiveness and need for treatment for dental fluorosis. The proportion of respondents perceiving teeth as unattractive, unsatisfactory and requiring treatment increased with increasing severity of dental fluorosis. Using agreement between the three negative perceptions as a measure, 14% of the sample perceived mild dental fluorosis as aesthetically objectionable, 45% at moderate level and 91% at severe levels. Negative perceptions of dental fluorosis were lower than reported previously. Three parameters were included in the approach to estimate aesthetically objectionable fluorosis which may provide a more realistic measure than those used previously. The nature of the index and the sample included suggest that findings of this survey provide a reasonable indicator of the likely impact of water fluoridation. Findings may have important implications for fluoridation policies in the United Kingdom and elsewhere.

How aesthetically objectionable is fluorosis?

This paper: Objectives A cross-sectional national survey to explore perceptions of dental fluorosis and to determine the proportion of people regarding fluorosis as aesthetically objectionable at differing levels of defect. Methods A survey using a multistage stratified random probability sample of 6,000 UK adult households. Face-to-face interviews were carried out using a structured questionnaire and photographs of different levels of dental fluorosis. Respondents were interviewed about the parameters of satisfaction, attractiveness and need for treatment for dental fluorosis. Results The proportion of respondents perceiving teeth as unattractive, unsatisfactory and requiring treatment increased with increasing severity of dental fluorosis. Using agreement between the three negative perceptions as a measure, 14% of the sample perceived mild dental fluorosis as aesthetically objectionable, 45% at moderate level and 91% at severe levels. Conclusion Negative perceptions of dental fluorosis were lower than reported previously. Three parameters were included in the approach to estimate aesthetically objectionable fluorosis which may provide a more realistic measure than those used previously. The nature of the index and the sample included suggest that findings of this survey provide a reasonable indicator of the likely impact of water fluoridation. Findings may have important implications for fluoridation policies in the United Kingdom and elsewhere.

Determining the optimal concentration of fluoride in drinking water in Pakistan.

This study was designed to determine the optimal concentrations of fluoride for drinking water in Pakistan. Clinical dental examination of 1020 school children aged 12 years was carried out in 19 cities of Pakistan. Correlation between concentrations of water fluoride, caries and fluorosis was investigated by analyzing the data on fluoride concentrations in drinking water in the sampled population for which the caries and the fluorosis levels were also measured. The optimal level of fluoride in drinking water is universally calculated by applying the equation of Galagan and Vermillion, which permits the calculation of water intake as a function of temperature. The annual mean maximum temperatures (AMMT) recorded during the last 5 years were collected from the meteorological centres of the 28 divisional headquarter stations. The average AMMT of Pakistan is 29 degrees C at which the optimal fluoride in drinking water of Pakistan was calculated to be 0.7 ppm. As drinking habits differ in various parts of the world, determination of optimal concentration of fluoride for drinking water in Pakistan was performed using a modified Galagan and Vermillion equation, which applies a correction factor of 0.56 to the equation. The optimal fluoride in drinking water in Pakistan using this modified equation was determined to be 0.39 ppm. Observation of the correlation showed that a fluoride concentration of 0.35 ppm in drinking water was associated with maximum reduction in dental caries and a 10% prevalence of fluorosis. Determining the most appropriate concentrations of fluoride in drinking water is crucial for communities. It is imperative that each country calculates its own optimal level of fluoride in drinking water based on the dose-response relationship of fluoride in drinking water with the levels of caries and fluorosis. Climatic conditions, dietary habits of the population and other possible fluoride exposures need to be considered in formulating these recommendations.

Fluoride ingestion from toothpaste: background to European Union-funded multicentre project.

As in most other established market economies throughout the world the prevalence of dental caries has declined in most Member States of the European Union (EU). There is evidence that the increased use of fluoride toothpaste has been a major factor in this improvement. Recently there has been increasing debate on the alleged link between increased use of fluoride toothpaste, particularly by infants and young children, and increased levels of enamel fluorosis. Central to these discussions are two issues, namely measurement of the amount of fluoride ingested by infants and young children and measurement of enamel opacities including fluorosis. The aims of the project described in this special issue addressed these two measurement issues. Seven EU Partners participated. Standardized methods for recording the amount of fluoride ingested when using fluoride toothpaste were developed and used in the seven sites. Similarly a standardized photographic method for recording enamel opacities, including fluorosis, was developed.

Source of drinking water and other risk factors for dental fluorosis in Sri Lanka

This study was done to describe the association between source of drinking water and other potential risk factors with dental fluorosis. Prevalence of dental fluorosis among 518 14-year-old students in the south of Sri Lanka was 43.2%. The drinking water sources of the students were described and fluoride samples were taken. There was a strong association between water fluoride level and prevalence of fluorosis. Tea drinking before 7 years of age was also an independent risk factor in a multivariate analysis. Having been fed with formula bottle milk as an infant seemed to increase the risk although the effect was not statistically significant. No clear effects could be found for using fluoridated toothpaste, occupation of the father, and socio-economic status. Drinking water obtained from surface water sources had lower fluoride levels (median 0.22 mg l−1) than water from deep tube wells (median 0.80 mg l−1). Most families used shallow dug wells and these had a median fluoride value of 0.48 mg l−1 but with a wide range from 0.09 to 5.90 mg l−1. Shallow wells located close to irrigation canals or other surface water had lower fluoride values than wells located further away. Fluoride levels have to be taken into account when planning drinking water projects. From the point of view of prevention of dental fluorosis, drinking water from surface sources or from shallow wells located close to surface water would be preferable.

Socio-Demographic Features and Fluoride Technologies Contributing to Higher Fluorosis Scores in Permanent Teeth of Canadian Children

Objective: To examine levels of fluorosis among children in two Canadian communities exposed to flouride. Background: One community had discontinued flouride, the other had maintained it. Water supplies, however, were fluoridated for all the children when their esthetically important teeth were mineralized. Methods: We examined 8,277 children to assess Thystrup-Fejerskov Index (TFI) scores. Multivariate Poisson regression models were used to identify the relationship between TFI and water fluoride status, age, gender, SES, and dietary and fluoride exposure histories (supplements, rinses, toothpaste amount, tooth brushing frequency, and tooth brushing starting age). Parent(s) completed questionnaires. Results: Overall, levels of fluorosis were low to mild, with residents of the fluoridation-ended communities having marginally higher TFI scores than those of the still-fluoridated community. Females had higher TFI scores than males. Children aged 10 years or more had higher TFI scores than younger children. Consuming bottled water between birth and 6 months of age was protective. Exposure to fluoridation technologies was consistently associated with fluorosis experience. Children who began brushing with fluoride toothpaste between their first and second birthdays had higher TFI scores than those who began between their second and third birthdays, regardless of daily brushing frequency. Children who regularly used supplements had higher TFI scores than those who did not. Children with a college-educated father had higher TFI scores than those whose fathers had less education. Conclusions: Higher fluoride exposure slightly increased the likelihood that a child had a higher TFI score, especially when more fluoridation technologies were used at home.

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The purpose of this study was to determine the frequency and severity of dental fluorosis in 5 to 12 and 15 year-old school children in the city of Marinópolis, São Paulo, Brazil, with the purpose of obtaining a baseline data for the monitoring dental fluorosis in this population. All of the school children in the both sexes, in the mentioned ages, enrolled in educational institutions and having the pre-requirement condition of to live in Marinópolis from their birth were involved, totaling 320 school children. The exams were made by one examiner previously calibrated to use the Dean Index. According to the results, the frequency of dental fluorosis in the studied group was 17.2%, however just considering the fluorosis levels that determine aesthetic compromising (mild, moderate and severe), this percentile was 7.19%. The predominant level was the very mild (10.0%) followed for the mild (5.3%), moderate (1.3%) and severe (0.6%). Concluding that the dental fluorosis in the studied population doesn't constitute in a problem with wide dimensions, however, subsequent studies are necessary in the attempt of identifying the causes of moderate and severe fluorosis cases.

Esthetically objectionable fluorosis attributable to water fluoridation.

We compared estimates of fluorosis prevalence and risk attributable to fluoridation using an index applied to the entire dentition and to the maxillary anterior teeth. We also estimated the prevalence of perceived esthetic problems attributable to current fluoridation policy (Attributable Burden). Fluorosis prevalence estimates were obtained from the National Survey of Oral Health in US School Children (1986-87) for the 1839 survey children aged 12 -14 years who were scored for fluorosis, had never received fluoride drops or tablets, and had lived in only one home. For each child we calculated Dean's fluorosis index, and an anterior fluorosis index (value of the highest scored maxillary anterior tooth). We used each index to calculate risk of fluorosis attributable to fluoridation by subtracting at each level of severity the prevalence of fluorosis among those living in low fluoride areas (F <or= 0.3 ppm) from the prevalence among those living in optimally fluoridated areas (0.7 ppm F <or=1.2 ppm). Findings from five published studies were used to calculate risk of perceived esthetic problem attributable to fluorosis, by severity, i.e. the difference in the mean percentage of respondents who were satisfied with the appearance of their teeth with and without fluorosis. Finally, Attributable Burden was estimated by summing the products of risk of perceived esthetic problems attributable to fluorosis and risk of fluorosis attributable to fluoridation for each level of fluorosis severity. Prevalence of fluorosis, very mild or greater, was 26% with Dean's Index, which was significantly higher than the 18% figure calculated with the anterior index. Using the anterior index, fluoridation was a risk factor for very mild (attributable risk = 15%) and mild fluorosis (attributable risk = 3%). Risk of fluorosis (very mild or greater) attributable to fluoridation was significantly higher when calculated from prevalence estimates using Dean's Index than estimates calculated with the anterior index (24% versus 18%). The mean values of risk of perceived esthetic problems attributable to very mild and mild fluorosis were 9% and 33%, respectively. We found that approximately 2% of US schoolchildren may experience perceived esthetic problems which could be attributed to the currently recommended levels of fluoride in drinking water. The findings further suggest that both estimates of fluorosis prevalence and risk of fluorosis attributable to fluoridation will be higher when calculated with an index applied to the entire dentition. Data were unavailable for fluoridated toothpaste and diluted formula consumption, thus the risk of fluorosis attributable to fluoridation may be overestimated if consumption was higher in fluoridated areas. The risk of perceived esthetic problems attributable to fluoridation must be weighed against its lifetime benefits and the associated costs of alternative solutions such as educating parents about appropriate toothpaste use and lowering the fluoride content of children's toothpaste.

An attempt to explain why Tanzanian children drinking water containing 0.2 or 3.6 mg fluoride per liter exhibit a similar level of dental fluorosis.

The aim of this study was to identify factors that might explain the similar level of prevalence and severity of dental fluorosis in two neighboring areas in Tanzania: Kibosho; 0.2 mg fluoride/l, n = 96 and Arusha; 3.6 mg fluoride/l in drinking water, n = 80. Subjects aged 8-16 years were examined for dental fluorosis using the Thylstrup and Fejerskov Index (TFI). Based on the score on the upper left central incisor, the prevalence was not significantly different between the communities (TFI > or = 1). The severity, however, was significantly higher in Arusha. The areas had different food habits, e.g., type of weaning food used, and the use of magadi, a fluoride containing salt. In Arusha, 99% of the children had been given lishe, which is a magadi-free weaning food. Conversely in Kibosho, 61% used lishe while 39% used the magadi-containing weaning food kiborou. Magadi was used as food tenderizer in 'adult food' by 98% in Kibosho and 45% in Arusha. Residential area and use of magadi explained 5% of the variance in TFI scores in inter-area analyses. In intra-area analyses, weaning food in Kibosho and use of magadi in Arusha had a significant effect, but the total explained variance was only 5 and 4%, respectively. Apart from fluoride in the drinking water, other sources of fluoride such as use of magadi in weaning food (kiborou) and in the adult food may partly explain the high prevalence and severity of dental fluorosis in the community with 0.2 mg fluoride per liter in the drinking water.

Intra-oral distribution of dental fluorosis in Newburgh and Kingston, New York.

Previous studies of intra-oral distribution of dental fluorosis in low-fluoride areas reported that teeth that formed later in life were more frequently affected compared with the early-forming teeth. The steady increase of plasma fluoride with age, even under constant fluoride exposure, has been suggested as a possible mechanism for this clinical manifestation. To determine the intra-oral distribution of Dean's Index scores and the effect of fluoride exposure on early- and late-forming teeth, we analyzed data collected on 2193 seven- to 14-year-old lifelong residents of fluoridated or non-fluoridated areas. Logistic regression procedures were used to determine the effects of fluoridation, early brushing, daily supplements, and other socio-demographic variables on early- and late-forming teeth. The results show that the occurrence of very mild or greater levels of fluorosis in the upper anterior teeth was 7 to 10% in the fluoridated area and 5 to 9% in the nonfluoridated area. In the fluoridated area, the occurrence of fluorosis increased from anterior to posterior teeth. Both early- and late-forming teeth were affected by exposure to fluoridation, daily fluoride supplement use, or brushing before the age of two years. This analysis showed that the esthetic consequence of exposure to multiple sources of fluoride was less dramatic, as evidenced by the lower frequency in upper anterior teeth compared with posterior teeth. The longer maturation process of the posterior teeth and the thicker enamel appear to be the likely explanation for the higher occurrence of dental fluorosis in posterior teeth.

Overview of the history and current status of fluoride supplementation schedules.

Clinical trials of dietary fluoride supplements began in the 1940s in an effort to bring the benefits of fluoride to those who did not receive it through their drinking water. Following the early success of these trials, the Council on Dental Therapeutics of the American Dental Association (ADA) published its first recommendations for fluoride supplementation in 1958. The American Academy of Pediatrics (AAP) followed with its own recommendations in 1972. During the 1970s a variety of alternative schedules appeared in the literature, most in reaction to the findings of unexpectedly high levels of enamel fluorosis in children being supplemented with the AAP schedule. In 1979 the ADA and AAP agreed on essentially identical schedules. During the 1980s, however, the prevalence of enamel fluorosis continued to increase, and fluoride supplements were found in some studies to be a risk factor for fluorosis. This finding prompted another round of dosage schedule recommendations in the early 1990s. This paper presents a history of fluoride dosage recommendations and reviews the recent proposals for reducing supplement dosage.

Paleopathology of skeletal fluorosis.

Skeletal fluorosis is one of a range of conditions causing excessive ossification and joint ankylosis in skeletons. It is rarely considered, however, in differential diagnoses of palaeopathological lesions. This paper considers the identification of skeletal fluorosis in a skeletal sample from the island of Bahrain, Arabian Gulf, dating to ca. 250 BC-AD 250. Approximately 4% of 255 adult skeletons in the sample have hyperostosic lesions resulting in joint ankylosis primarily of the lumbar vertebrae, as well as the major joints. These lesions most frequently occur among males in the 50+ age group. Chemical analysis on a small series of bone and dental samples confirmed the presence of high levels of fluoride, while staining of the teeth is evidence of dental fluorosis. The level of dental fluorosis is comparable with a naturally occurring fluoride level in water of between 1-2 ppm. The prevalence of hyperostosic lesions, however, appears higher than expected, and two possible reasons are suggested: confusion between a diagnosis of diffuse idiopathic skeletal hyperostosis and skeletal fluorosis on partial or less severely affected skeletons; and the presence of predisposing factors for skeletal fluorosis on the island in the past.

Prevalência de fluorose dentária em escolares de Brasília - Distrito Federal

Com a finalidade de avaliar a prevalência de fluorose dentária, foi realizado levantamento epidemiológico em Brasília, Distrito Federal, comunidade na qual o teor de flúor na água de abastecimento público é de 0,8 ppm. Foram examinadas 833 crianças de ambos os sexos com idades variando entre 8 e 12 anos, escolares e residentes em Brasília desde o nascimento. Os exames foram realizados em escolas públicas, em cadeira comum, sob luz natural e campo seco obtido com auxílio de gaze. Por meio do exame dos dentes permanentes anteriores superiores foi levantado o índice de fluorose entre os sexos. O percentual de crianças livres de fluorose apresentou-se elevado (85,36%), enquanto 14,64% mostraram níveis de fluorose dentária entre muito leve e moderado.

Dental fluorosis and the use of a high fluoride-containing trona tenderizer (magadi).

It has recently been suggested that magadi, a high-fluoride trona, which is added in cooking to tenderize certain vegetables and beans in two villages in Tanzania, significantly contributed to the prevalence and severity of dental fluorosis. This report aims to substantiate the significance of magadi as a determinant of dental fluorosis. Eighteen villages in four geographical areas (districts) with water supplies containing 0.2 to 0.8 mg/L of fluoride were selected. All schoolchildren aged 12 to 17 years (n = 1566) who had been born and raised in these villages were examined for dental fluorosis according to the Thylstrup-Fejerskov Index. Dietary history was recorded. The fluoride content of magadi samples was determined and the urinary fluoride excretion of pre-schoolchildren was assessed. The prevalence of dental fluorosis in nine coastal villages where tea and seafish were regularly consumed ranged from 7% to 46%. Severe (pitting) dental fluorosis was rarely seen. The low fluorosis levels observed in non-magadi consuming communities in coastal villages indicate that a fluoride content of up to 0.8 mg/L in drinking water is acceptable under the prevailing conditions of temperature and diet. In contrast, the prevalence of dental fluorosis in nine villages located inland at 1500 m altitude, where fluoride-containing magadi was consumed, ranged from 53% to 100%, and severe (pitting) fluorosis was highly prevalent, ranging from 18% to 97%. The village with the highest fluoride content in the magadi samples collected showed the highest level of fluorosis. The urinary fluoride excretion of pre-schoolchildren from different villages corresponded with the level of fluorosis and the fluoride content in the magadi samples of the respective villages. Data on dental fluorosis from the magadi-consuming communities provide strong evidence that consumption of magadi was the major determinant of the observed high prevalence and severity of fluorosis in inland villages at 1500 m altitude.

Epidemiologic Indices for Measuring the Clinical Manifestations of Dental Fluorosis: Overview and Critique

Several indices have been used to describe the clinical appearance of dental fluorosis. The purpose of this paper is to describe and compare the three principal ones in use today: those developed by Dean (1934, 1942), Thylstrup and Fejerskov (1978), and Horowitz et al. (1984). A recent index (Fluorosis Risk Index) developed by Pendrys (1990) is also included in this review. The continued use of Dean's classification system and derived index (CFI) for more than a half century is testimony to its simplicity and utility. The index has been criticized because the unit of analysis is the person, because criteria are unclear for some categories, or that they lack sensitivity, particularly for severe fluorosis, and because of the way in which data are summarized and reported. The Thylstrup and Fejerskov Index is appealing to clinicians and epidemiologists alike in that it corresponds closely to histological changes that occur in dental fluorosis and to enamel fluoride concentrations, thereby having biological validity. The TSIF described by Horowitz et al. makes a useful contribution because it provides clearer diagnostic criteria and provides for an analysis based on esthetic concerns. The Fluorosis Risk Index appears to be particularly useful for analytical epidemiologic studies, because it is designed to permit a more accurate identification of associations between age-specific exposures to fluoride and the development of dental fluorosis. All three indices in common use today provide useful indices for the study of dental fluorosis. The utility of the Fluorosis Risk Index will be determined as it receives wider use. The selection of one of these indices for use in an epidemiologic study depends in large measure on the purpose of the study. Research needs to continue on the validity of these indices, particularly for mild fluorosis, and on the public's perception of the cosmetic appearance of teeth with different severity levels of fluorosis.