Dean's Index Research Articles

Fluorose dentária em escolares de um município da serra gaúcha, Rio Grande do Sul, Brasil

The aim of the present study was to determine the prevalence and severity of dental fluorosis in all schoolchildren (ages 4 to 18 years, n = 259) from the town of Santa Tereza, Rio Grande do Sul, Brazil, and to investigate associated factors. Data were obtained through a questionnaire and by means of clinical tests. Dean's index was used to determine fluorosis occurrence. Prevalence of fluorosis was 63.7%. The predominant category was very mild (43.6%), followed by mild (12.0%), moderate (7.7%), borderline (7.3%), and severe (0.4%). Approximately 85.0% of the schoolchildren currently have, or have had, access to other topical sources of fluoride. Significant associations were found between place of residence and previous or ongoing fluoride mouth rinsing and prevalence and severity of fluorosis (p < 0.05). There was also a significant association between dental fluorosis and parents' level of schooling, frequency of brushing teeth, fluoride rinsing, and use of fluoride gel (p < 0.05).

Fluorosis dental en escolares del departamento de Caldas, Colombia.

A prevalence survey of dental fluorosis was conducted among primary school students in Caldas, a small province in west central Colombia. The cross-sectional study compared the prevalence of dental fluorosis in the four regions of Caldas. In the urban area, a probabilistic sample was selected and,in the rural areas, students were sampled in locations that were readily accessible. One thousand sixty-one students were examined while at school in daylight conditions. The surveillance tool applied was the Dean Index. Univariate and bivariate analyses were made with a chi-square test being applied for the latter to show independence among variables. Sixty-three percent (95% CI: 60-66%) of primary school students were affected by fluorosis to some degree of severity. Among them, 56% (95% CI: 52-59) were classified in the mild and very mild degrees, whereas 7% (95% CI: 2-16) were classified as moderate or severe. A statistically significant association between the region variable and dental fluorosis was observed. However, no association was found with gender, area, schooling or age variables. Within Caldas, the eastern region showed the lowest prevalence (47.9%) in contrast to the other three areas (northern, central-south and western) where prevalences exceeded 68%. At least two of three primary school students in Caldas suffer from some degree of dental fluorosis.

Prevalence of dental fluorosis in 12 and 15 years old schoolchildren in Salvador, Bahia, Brazil, 2001

This study aimed to determine the prevalence of dental fluorosis in a sample of 3,313 schoolchildren (ages 12 and 15) in a health district in Salvador, Bahia, Brazil. A cross-sectional study was developed, and data were collected by seven examiners (kappa = 0.69) according to WHO criteria (the Dean index). Additional information such as participation in programs, access to a dentist, place of residence from 0-5 years of age, sex, and ethnicity were obtained through a questionnaire. A descriptive analysis was performed for the municipality as a whole and for each district. According to the results, 31.4% of the 12-year-olds and 27.6% of the 15-year-olds presented fluorosis, predominantly of the "very mild" type. Differences were found between the districts (p<0.05). The districts of Pau da Lima and Brotas had the highest percentages of healthy individuals at 12 years of age (81.8% and 81.6%). At 15 years, Subúrbio Ferroviário, Pau da Lima, and Cajazeiras were the districts with the lowest prevalence rates (13.0%, 14.6%, and 13.5%). The district of Liberdade had the highest prevalence (72.4% and 57.3%) at 12 and 15 years, respectively, attributed to differences in calibration. Differences were found between the health districts, thus emphasizing the need for health surveillance.

Dental fluorosis: epidemiological fiction?

To review the scientific literature concerning dental fluorosis and to evaluate its occurrence among children attending public schools in the city of Curitiba, which is in the state of Paraná in Brazil. We reviewed the international literature on fluorosis that was published between 1998 and 2001, focusing on systematic critical reviews that were listed in such electronic bibliographical sources as MEDLINE, LILACS, the Cochrane Library, and Sci-ELO Public Health. In addition, in 2000 we carried out a cross-sectional study with 12-year old schoolchildren (n = 1,494) in Curitiba. Our literature review found that there is still much controversy regarding the benefits associated with fluoride supplementation and the impact of fluorosis. In our cross-sectional study with the Curitiba schoolchildren, we found a fluorosis prevalence of 23% for grade 2, 3, 4, or 5 on the Dean index. The observed fluorosis had little impact on the biopsychosocial health of the children studied, as shown by the multivariate logistic regression analysis. The analysis showed that the presence of fluorosis was not significantly associated with dissatisfaction with tooth color. However, there was an association between the independent variable of place of residence (sanitary district within Curitiba) and fluorosis (P = 0.00), in both the bivariate and multivariate analyses. Based on our results, we concluded that dental fluorosis is not now a crucial epidemiological problem for the population studied in Curitiba. Any initiatives to control fluorosis should take into account the population's perception of the problem. Nevertheless, it is still extremely important to monitor the levels of fluoride in drinking water.

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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.

Naturally fluoride contained of drinking water and the prevalence of dental fluorosis in Ninevah Governorate, Iraq

The purpose of the study was to determine the prevalence of dental fluorosis in a group of school students lived in area with high and low natural fluoride contained drinking water in Ninevah Governorate. The study was conducted among (1724) school's students aged (11-16) years from randomly selected schools (primary and intermediate) in two provinces in Ninevah Governorate. Eight hundred and thirteen students who had lived since birth in high natural fluoride level area (Sinjar province) (2.05-2.22 ppm) and (911) students lived continuously from birth in low natural fluoride level area in their drinking water (Talkaif province) (0.11-0.19 ppm). Dean index has been used to assess the dental fluorosis. The results show that the prevalence of dental fluorosis in Sinjar province is (97.3%) within individual and (62.9%) within teeth, ranging from very mild to mild form of dental fluorosis, with no significant sex difference, but the percentage of severity has been found to be increasing with age, while the prevalence of dental fluorosis in Talkaif province was (5.5%) within individual and (1.2%) within teeth, with no significant sex difference. The community fluorosis indices for Sinjar and Talkaif provinces are (1.7 and 0.1) respectively. This difference is due to the difference in level of natural fluoride in both provinces drinking water supplies.

Dental Fluorosis And Caries Status Among 12-13 Year-old School Children In Klang District, Malaysia

Several national studies have been undertaken to assess the prevalence of fluorosis utilizing the Dean's Index. However, the latest national study undertaken in 1997 (1) had utilized the DDE Index and hence does not allow comparisons to be made with the earlier set of national data. This cross-sectional study was undertaken to evaluate the prevalence of dental fluorosis using the Dean's Index in a sample of 12-13 year-old schoolchildren and to assess the relationship between fluorosis and their caries status. The sampling procedure involved a multistage, clustered and stratified random sampling. The sample comprised of 1519 schoolchildren attending 20 secondary government and governmentaided schools in fluoridated urban and rural areas of Klang District in Peninsular Malaysia. There were 772 males and 747 females. Each subject was administered a questionnaire to elicit the demographic information. Intra-oral examination for dental fluorosis and caries was performed for each subject. The results demonstrated that more than half of the subjects (54 %) had no fluorosis, 13.2% had questionable fluorosis, 31.3% had very mild to mild fluorosis, 1.4% had moderate fluorosis and only 0.1 % exhibited severe fluorosis. The mouth prevalence was 32.8 %. The Community Fluorosis Index was 0.48 indicating a borderline score for public health significance. Fifty-two percent of the children were caries free. The mean DMFT for all subjects was 1.1, F(0.6) being the main component. Although girlshad a higher mean DMFT score as compared to boys this difference was not significant. Significant differences in DMFT scores were observed by urbani rural distributions and ethnic groups (p &lt; 0.01). No significant correlation was found between fluorosis and caries status. It is concluded that dental fluorosis does not appear to be a public health problem. Further coordinated in-depth research using similar criterias for assessing dental fluorosis is highly recommended.

Effect of morphodynamics on the spatial and temporal variation of macrofauna on three sandy beaches, Rio de Janeiro State, Brazil

Three exposed sandy beaches were selected to compare fluctuations in density of the most abundant species, and to verify the influence of spatial and temporal variations on the community structure. Sampling was carried out every three months, from June 1993 to May 1995, on Fora, Prainha, and Boqueirão Beaches. The first two beaches were classified by Dean's morphodynamic index (Ω) as intermediate, and the last as reflective. Slope, beach width and median grain size were significantly different among the beaches. Two-way analysis of variance revealed significant differences in species richness only among the beaches. No significant differences in density of the macrofauna between beaches and season were observed. However, Prainha Beach showed a higher temporal variation of the density of the macrofauna (and higher standard deviation) than the other two beaches. Emerita brasiliensis (Crustacea: Decapoda), Excirolana braziliensis (Crustacea: Isopoda), and Pseudorchestoidea brasiliensis (Crustacea: Amphipoda) were the most abundant species. Canonical correspondence analysis calculated the influence of the temporal variation as 27·5%; the influence of the environmental variation on community structure was 20·9%. The results suggest that in spite of the long-term fluctuations in species density, the beaches did not have temporal differences in the species richness and total density macrofauna during the study period.

Varied Ecological Environment and Fluorosis in Tibetan Children in the Nature Reserve of Mount Qomolangma

To determine the extent of brick tea consumption fluorosis in children living at elevations of 2000 and 4300 m, 519 children aged 8–15 years living in Xiege'er Town at 4300 m and Zhangmu Town at 2000 m were examined for dental fluorosis, their urinary fluoride concentration was determined, their dietary structure investigated, and the fluoride concentrations of various foods, freshwaters, soils, and fuels determined. Fifteen Tibetan families living in these two areas of the nature reserve of Mount Qomolangma were studied according to UNEP, FAO, and WHO guidelines for the study of dietary intake of chemical contaminants, Horowitz's classification and examination of dental fluorosis, and Dean's dental fluorosis index. The results demonstrated that dental fluorosis in Tibetan children living at an elevation of 2000 m was significantly lower than that of children at 4300 m (P<0.01). Higher elevation can worsen the extent of fluorosis, leading to retention of fluoride in tissues as a result of hypoxia, but fluorosis can also be associated with the deterioration of the ecological environment at high elevation and a low-level economy. Beverages and foods mixed with brick tea water are responsible for the dental fluorosis in the children.

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.

Fluoride exposure and dental fluorosis in Newburgh and Kingston, New York: policy implications.

This analysis was conducted to determine the changes in the effect of exposure to fluoridation and other sources of fluoride on dental fluorosis in children attending Newburgh and Kingston school districts in New York State. Data for this analysis were obtained from two surveys conducted in the 1986 and 1995 school years. Analyses were limited to 3500, 7-14-year-old lifelong residents of a fluoridated or a nonfluoridated community. Dean's classification and DMFS index were used for recording dental fluorosis and caries, respectively. A questionnaire was used to collect fluoride exposure data. Regression procedures were used to estimate the effect of fluoridation, fluoride supplements, and brushing before the age of 2 years on dental fluorosis. Children examined in 1996 were at higher risk for both questionable and very mild to severe dental fluorosis if they received fluoride from water or daily tablet use, or started brushing before the age of 2 years. The increase in risk from 1986 to 1995 was greater for African-American children. This analysis showed that the risk of developing dental fluorosis did not decline over time in these communities. Continuous exposure to water fluoridation had an observable effect on dental fluorosis. However, implementation of fluoridation in Newburgh Town did not result in an increase in dental fluorosis prevalence.

Prevalence of dental fluorosis in Sudanese children from two villages with 0.25 and 2.56 ppm fluoride in the drinking water.

Dental fluorosis is endemic in Eastern Africa and a high prevalence has been found even in low-fluoride (approximately 0.5 ppm) areas. Substantial seasonal changes in the fluoride content of water have also been reported. The aim of the present study was to ascertain, through one year, the fluoride concentration in water from two underground reservoirs in Sudan, in Treit el Biga (TeB) and Abu Groon (AG), and to assess dental fluorosis in children aged 7-16 years who had been lifelong residents. The water in one of the reservoirs (TeB) was shown to have a low, very stable fluoride concentration (0.25 ppm SD 0.04) whereas the other (AG) had a tenfold higher, and slightly varying, fluoride concentration (2.56 ppm SD 0.26). Dental fluorosis was recorded on maxillary central incisors according to Dean's index. In TeB 91% of the children showed signs of dental fluorosis whereas in AG all children had fluorotic teeth. The Community Fluorosis Index in TeB and AG was 1.40 and 2.44, respectively. There was a significantly higher degree of fluorosis in boys than in girls in the low-fluoride area. In TeB, older boys tended to have more fluorosis than younger boys; the difference, however, was not statistically significant. No significant sex or age differences in fluorosis were found in AG. In both villages great inter-individual variations in dental fluorosis were recorded. The prevalence and severity of dental fluorosis in TeB was higher than that previously reported in areas with similar fluoride concentrations in the drinking water.

Prevalence and severity of dental fluorosis in a Mexican community with above-optimal fluoride concentration in drinking water.

The purpose of this study was to determine the prevalence and severity of dental fluorosis in children living in a community at 2066 m above sea level. The water fluoride concentration of this community was 2.8 ppm. The population selected encompassed 10-12-yr-old schoolchildren who were life-long residents of the area. The modified Dean Index was used to estimate the severity of fluorosis. A total of 93 children participated in the study. They all showed evidence of dental fluorosis. Fifty-seven percent had moderate fluorosis, and 19% severe fluorosis. The high prevalence and severity of fluorosis in the population examined emphasized the need to study the factors determining dental fluorosis in Mexican communities.

Characterization of fluorosed human enamel by color reflectance, ultrastructure, and elemental composition.

Mature fluorosed human enamel has been described as a subsurface enamel hypomineralization, with porosity increasing relative to the degree of fluorosis. The purpose of the current study was to quantitatively measure the color of the fluorosed enamel by light reflectance, and to further characterize the enamel by scanning electron microscopy. Teeth with varying degrees of fluorosis were obtained and divided in groups of mild, moderate and severe fluorosis using Dean's index for fluorosis. The color of the labial enamel surface was measured using a Minolta Chroma Meter CR241 (Minolta, Ramsey, N.J., USA). The teeth were further characterized for elemental composition using an energy-dispersive spectrometer, and imaged in both secondary and backscattered electron modes. The results of this study showed that the moderately and severely fluorosed enamel contained an uneven distribution of areas which were more electron-absorbent with a relatively increased carbon content. The changes in the physical characteristics of the teeth could be quantitated by measurements of light reflectance. The color of the teeth was significantly different between groups, with all groups significantly different than normal.

Comparison of two indices of dental fluorosis in low, moderate and high fluorosis Tanzanian populations

This study aimed at comparing the Thylstrup-Fejerskov index (TFI) and the Dean's Index (DI) which were applied on three communities with different severity of dental fluorosis. A total of 1565 children aged between 11 and 18 yr with a mean age of 14.7 were examined for dental fluorosis with the TFI and 1155 of these children were also examined with the DI. The measurement error for the TFI was 0.50 (10 scale point) compared to 0.53 for DI (6 scale point). The Kappa values and the measurement-remeasurement correlation appeared to be better for the TFI. No difficulties were encountered in applying the TFI in contrast to the DI, which caused uncertainties in assessing the "questionable" and "very mild" scores, and this may explain the relatively better reproducibility of the TFI. The correspondence between both indices was determined. TFI 0 corresponded well with DI 0. The conversion values for TFI 1, 2, 3 and 4 into DI scores were 0.3, 0.8, 1.4 and 2.4 respectively. The TFI 5-9 corresponded with DI score 4. TFI could discriminate the severe forms of dental fluorosis which were categorized in Dean's highest score 4. TFI was able to reveal more dental fluorosis than DI in communities with minor and moderate dental fluorosis. In the community with severe dental fluorosis where more than 85% of all teeth exhibited a DI > or = 1, both indices revealed a comparable prevalence of dental fluorosis. The TFI is considered a near ideal instrument.

Determining optimal levels of fluoride in drinking water for hot, dry climates--a case study in Sri Lanka.

The prevalence of dental caries and dental fluorosis was examined in 380 14-yr-old children living in four geographic areas of Sri Lanka with water F-levels of 0.09-8.0 ppm. A reduction in caries prevalence by 43% was recorded in children consuming 0.6-0.79 ppm F- compared to those in low fluoride areas (< 0.4 ppm). Among those consuming drinking water containing < 1.0 ppm F-, however, 32% of the children had mild forms and 9% severe forms of dental fluorosis (Dean's index). Although other sources of F- may contribute to this effect, the prevalence and severity of dental fluorosis seen in low fluoride areas was confirmed to be high in rural Sri Lanka. Our data are comparable with recent findings from other tropical countries, e.g. Kenya and Senegal, and reaffirm that WHO guidelines for the upper limit of F- in drinking water may be unsuitable for developing countries with a hot, dry climate. Current knowledge now enables us to recommend 0.8 ppm as an appropriate upper limit for F- in drinking water supplies for these populations.

Prevalence of enamel defects/fluorosis in fluoridated and non-fluoridated areas in Ireland.

Water fluoridation was introduced in Ireland in 1964 and in recent years the availability of fluoride from other sources had increased. As part of a National Survey of Children's Health in Ireland Dean's and the DDE indices were used to determine the prevalence of enamel fluorosis/defects in 8- and 15-yr-old children in fluoridated and non-fluoridated areas. Over 94% of the children examined in all areas were regarded as having normal enamel, as defined by Dean's index, the remainder showing evidence of either questionable, very mild or mild fluorosis. Between 52% and 63% of the children had one or more teeth affected by enamel defects when measured by the DDE index. The prevalence of enamel fluorosis/defects was similar in children living in fluoridated and non-fluoridated areas but the prevalence of diffuse opacities (DDE) was higher in the fluoridated areas.

中国広州市のｆｌｕｏｒｉｄａｔｉｏｎ中断後のう蝕予防効果持続と歯牙フッ素症歯所有状況

In China, water fluoridation was begun in Guangdong province in Guangzhou in 1965 and in Dongguan in 1974, and was stopped in 1983 and 1986, respectively. There is at present no fluoridation being practiced in China. Both cities are located north of Hong Kong and belong to the subtropical zone (mean temperature=71.1°F). According to Minoguchi's formula, an optimal fluoride concentration is 0.6-0.7ppm. The fluoride concentration was unstable for the first 10 years, when annual fluoride concentrations ranged from 0.8ppm to 0.9ppm, higher than the optimal fluoride concentration. After that the concentration was about 0.7ppm. The fluoride concentration of drinking water in Guangzhou may have been sometimes higher than the optimal fluoride concentration. In December 1990, seven years after fluoridation was discontinued, a dental survey of schoolchildren aged 15 was made in Guangzhou, and also in Fushan (0.2ppm) as a control area. Two dentists examined dental caries and one dentist examined dental fluorosis with Dean's Index, and other enamel defects were also recorded. Subjects were 62 students in Guangzhou and 71 students in Fushan. The mean DMFT was 0.44 (SE=0.10) in Guangzhou and 2.20 (0.33) in Fushan. The percent difference was 80% (p<0.001). The prevalence rate of dental fluorosis was 21% in Guangzhou and 2.8% in Fushan and the CFI was 0.42 and 0.08, respectively. Many dark brown teeth, not caused by fluoride, were found. They may have been caused by tetracycline or exanthematous fevers. The present study proved that water fluoridation produced high caries-preventive effects and the favorable effects remained for seven years after discontinuation of water fluoridation without serious dental fluorosis in Guangzhou.

Dental Fluorosis Following Downward Adjustment of Fluoride in Drinking Water

The drinking water fluoride concentration in Hong Kong was reduced by about 0.2 ppm in June 1978. This study was undertaken to determine whether the prevailing level of dental fluorosis was affected by such a minor change. Cohorts of children (N = 1,062) aged seven to 12 years, who were born both before and after the fluoride reduction, were examined clinically using Dean's fluorosis index. Based on upper right central incisors, dental fluorosis prevalence decreased from 64 to 47 percent and the community fluorosis index decreased from 1.01 to 0.75 (P less than .01). Thus, dental fluorosis was reduced, although the reduction in water fluoride concentration was not sufficient to achieve the minimal fluorosis level that Dean associated with a fluoride concentration optimal for caries prevention. Variation in dental fluorosis has been reported previously to result from marked sudden changes, during tooth formative years, to drinking water fluoride concentration. This study confirms preliminary findings that variation in dental fluorosis arising from minor changes to the fluoride level in drinking water is also measurable.