Comparison of dental esthetic perceptions of young adolescents and their parents.

OBJECTIVES: To compare dental esthetic perceptions of adolescents at age 13 with those of parents and to assess associations with dental fluorosis. METHODS: Adolescents aged 13 underwent dental examinations for fluorosis on maxillary anterior teeth using the Fluorosis Risk Index. Adolescents and parents completed questionnaires concerning satisfaction with adolescents' dental appearance. McNemar and Bowker tests of symmetry were used for comparisons of esthetics ratings between parents and adolescents. Comparison of satisfaction between subjects with fluorosis and subjects with no fluorosis was made using Cochran-Armitage Trend and Fisher's Exact tests. RESULTS: From 376 adolescents included in the study, 26 percent had definitive fluorosis, mostly at a mild level. Fifteen percent of adolescents were dissatisfied with dental appearance, and concerns were mainly about color (45 percent) and alignment (35 percent). Adolescents were less satisfied with overall dental appearance (P < 0.001) and color (P = 0.048) and more concerned about tooth shape (P = 0.002) than were their parents. Fluorosis status (yes/no) was not significantly associated with adolescents' perceptions (P > 0.05). Parents of subjects with fluorosis were more dissatisfied with dental appearance (P = 0.014) and color (P < 0.001) than other parents. The number of maxillary anterior zones exhibiting fluorosis was negatively associated with adolescent (P = 0.03) and parent (P = 0.002) satisfaction. CONCLUSION: Adolescents generally had less satisfaction with dental appearance and color, and were more concerned with tooth shape than were parents. For both parents and adolescents, decreased satisfaction was associated with the number of zones with definitive fluorosis.

Fluoride content of solid foods impacts daily intake.

OBJECTIVE: To determine the amount of fluoride received from solid foods for a cohort of children. METHODS: Parents were asked to complete questionnaires for the preceding week and dietary diaries for 3 days for their children. Data collected at 6, 9, 12, 16, 20, 24, 36, 48, and 60 months were analyzed cross-sectionally. RESULTS: At 6 months of age, children ingested an estimated mean of 8 percent of dietary fluoride from solid foods. At 12 months of age, children ingested an estimated 39 percent of dietary fluoride from solid foods. Although the percentage of fluoride intake from solid foods stabilized from 24 to 60 months (means of 36-39 percent), some children received as much as 85-88 percent of their dietary fluoride from solid foods. CONCLUSIONS: Some children receive a substantial portion of dietary fluoride from solid foods.

Examiner reliability of fluorosis scoring: a comparison of photographic and clinical examination findings.

OBJECTIVE: To assess and compare examiner reliability of clinical and photographic fluorosis examinations using the Fluorosis Risk Index (FRI) among children in the Iowa Fluoride Study (IFS). METHODS: The IFS examined 538 children for fluorosis and dental caries at age 13 and obtained intraoral photographs from nearly all of them. To assess examiner reliability, duplicate clinical examinations were conducted for 40 of the subjects. In addition, 200 of the photographs were scored independently for fluorosis by two examiners in a standardized manner. Fluorosis data were compared between examiners for the clinical exams and separately for the photographic exams, and a comparison was made between clinical and photographic exams. For all three comparisons, examiner reliability was assessed using kappa statistics at the tooth level. RESULTS: Interexaminer reliability for the duplicate clinical exams on the sample of 40 subjects as measured by kappa was 0.59, while the repeat exams of the 200 photographs yielded a kappa of 0.64. For the comparison of photographic and clinical exams, interexaminer reliability, as measured by weighted kappa, was 0.46. FRI scores obtained using the photographs were higher on average than those obtained from the clinical exams. Fluorosis prevalence was higher for photographs (33 percent) than found for clinical exam (18 percent). CONCLUSION: Results suggest that interexaminer reliability is greater and fluorosis scores are higher when using photographic compared with clinical examinations.

Tracking of TV and video gaming during childhood: Iowa Bone Development Study.

BACKGROUND: Tracking studies determine the stability and predictability of specific phenomena. This study examined tracking of TV viewing (TV) and video game use (VG) from middle childhood through early adolescence after adjusting for moderate and vigorous physical activity (MVPA), percentage of body fat (% BF), and maturity. METHODS: TV viewing and VG use were measured at ages 5, 8, 11, and 13 (n = 434) via parental- and self-report. MVPA was measured using the Actigraph, % BF using dual-energy x-ray absorptiometry, and maturity via Mirwald predictive equations. Generalized Estimating Equations (GEE) were used to assess stability and logistic regression was used to predict children "at risk" for maintaining sedentary behaviors. Additional models examined tracking only in overfat children (boys ≥ 25% BF; girls ≥ 32% BF). Data were collected from 1998 to 2007 and analyzed in 2010. RESULTS: The adjusted stability coefficients (GEE) for TV viewing were 0.35 (95% CI = 0.26, 0.44) for boys, 0.32 (0.23, 0.40) for girls, and 0.45 (0.27, 0.64) for overfat. For VG use, the adjusted stability coefficients were 0.14 (0.05, 0.24) for boys, 0.24 (0.10, 0.38) for girls, and 0.29 (0.08, 0.50) for overfat. The adjusted odds ratios (OR) for TV viewing were 3.2 (2.0, 5.2) for boys, 2.9 (1.9, 4.6) for girls, and 6.2 (2.2, 17.2) for overfat. For VG use, the OR were 1.8 (1.1, 3.1) for boys, 3.5 (2.1, 5.8) for girls, and 1.9 (0.6, 6.1) for overfat. CONCLUSIONS: TV viewing and VG use are moderately stable throughout childhood and predictive of later behavior. TV viewing appears to be more stable in younger children than VG use and more predictive of later behavior. Since habitual patterns of sedentarism in young children tend to continue to adolescence, early intervention strategies, particularly to reduce TV viewing, are warranted.

Relative validity of an FFQ for assessing dietary fluoride intakes of infants and young children living in Iowa.

OBJECTIVE: To determine the relative validity of a quantitative FFQ in assessing dietary fluoride intakes using 3 d food and beverage diaries for reference. DESIGN: Parents were asked to complete questionnaires for the preceding week and diaries for 3 d for their children. Fluoride intakes were estimated from 'selected' foods and beverages for questionnaires and from 'all foods and beverages' for diaries. Data collected at 6, 9, 12, 16, 20, 24, 36, 48 and 60 months were analysed cross-sectionally. SETTING: A 3 d food and beverage diary and an FFQ collected through mail from children living in the state of Iowa. SUBJECTS: Children from the Iowa Fluoride Study whose parents completed both an FFQ and a 3 d food and beverage diary at each analysed time point. RESULTS: Correlations between daily mean dietary fluoride intake estimated from questionnaires and diaries range from 0·90 to 0·65. CONCLUSIONS: A quantitative FFQ can provide relative estimates of dietary fluoride intake.

Amoxicillin use during early childhood and fluorosis of later developing tooth zones.

OBJECTIVES: Amoxicillin use has been reported to be associated with developmental defects on enamel surfaces. This analysis assessed the association between amoxicillin use and fluorosis on late-erupting permanent teeth. METHODS: As part of the Iowa Fluoride Study, subjects were followed from birth to 32 months with questionnaires every 3-4 months to gather information on fluoride intake and amoxicillin use (n = 357 subjects for this analysis). Permanent tooth fluorosis on late-erupting zones was assessed by three trained dentists using the fluorosis risk index (FRI) at approximately age 13. A case was defined as fluorosis if a subject had at least two FRI classification II zone scores of 2 or 3. Chi-square tests and logistic regression were used, and relative risks (RRs) and odds ratios (ORs) were calculated. RESULTS: There were 113 cases and 244 controls. In bivariate analyses, amoxicillin use from 20 to 24 months significantly increased the risk of fluorosis on FRI classification II zones [44.2 percent versus 30.4 percent, [RR = 1.45, 95 percent confidence interval (CI) 1.05-2.04], but other individual time periods did not. Multivariable logistic regression confirmed the increased risk of fluorosis for amoxicillin use from 20 to 24 months (OR = 2.92, 95 percent CI = 1.34-6.40), after controlling for otitis media, breast-feeding, and fluoride intake. CONCLUSIONS: Amoxicillin use during early childhood could be a risk factor in the etiology of fluorosis on late-erupting permanent tooth zones, but further research is needed.

Longitudinal associations between children's dental caries and risk factors.

UNLABELLED: Dental caries is a common disease in children of all ages. It is desirable to know whether children with primary, mixed, and permanent dentitions share risk factors for cavitated and non-cavitated caries. OBJECTIVE: To assess the longitudinal associations between caries outcomes and modifiable risk factors. METHODS: One hundred and fifty-six children in the Iowa Fluoride Study met inclusion criteria of three dental examinations and caries-related risk factor assessments preceding each examination. Surface-specific counts of new non-cavitated caries and cavitated caries at the primary (Exam 1: age 5), mixed (Exam 2: age 9) and permanent (Exam 3: age 13) dentition examinations were outcome variables. Explanatory variables were caries-related factors, including averaged beverage exposure frequencies, tooth brushing frequencies, and composite water fluoride levels collected from 3-5, 6-8, and 11-13 years, dentition category, socioeconomic status, and gender. Generalized linear mixed models (GLMMs) were used to explore the relationships between new non-cavitated or cavitated caries and caries-related variables. RESULTS: Greater frequency of 100 percent juice exposure was significantly associated with fewer non-cavitated and cavitated caries surfaces. Greater tooth brushing frequency and high socioeconomic status (SES) were significantly associated with fewer new non-cavitated caries. Children had significantly more new cavitated caries surfaces at the mixed dentition examination than at the primary and permanent dentition examinations. CONCLUSIONS: There were common caries-related factors for more new non-cavitated caries across the three exams, including less frequent 100 percent juice exposure, lower tooth brushing frequency and lower SES. Less frequent 100 percent juice exposures might be associated with higher exposures to several other cariogenic beverages.

Mixed dentition cavitated caries incidence and dietary intake frequencies.

PURPOSE: This study examined risk factors for children having new cavitated caries between 5 and 9 years old. METHODS: Subjects were Iowa Fluoride Study cohort children (mostly Caucasian and of relatively high socioeconomic status) with both primary and mixed dentition caries exams and at least 2 diet diaries recorded between 5 and 8 years old (N=198). Using surface-specific transitions, combined counts of new cavitated caries (d(2-3)f and/or D(2-3)F) were determined from 4 primary second molars, 8 permanent incisors, and 4 permanent molars. Food and beverage intake frequencies were abstracted. Other factors were assessed using periodic questionnaires. Logistic regression identified predictors of new cavitated caries. RESULTS: Thirty-seven percent had new cavitated caries. The mean new cavitated caries count for all children was 1.17 surfaces (±2.28 SD). In multivariable logistic regression, the following were significantly associated (P<.10) with having new cavitated caries: noncavitated caries experience at 5 years old (odds ratio [OR]=2.67, P=.03); cavitated caries experience at 5 years old (OR=3.39, P=.004); greater processed starch at snack frequency (OR=3.87, P=.07); being older (OR=1.68, P=.04); and less frequent tooth-brushing (P=.001). CONCLUSION: Results suggested that increased tooth-brushing frequency and reduced consumption of processed starches as snacks may reduce caries incidence in younger school-aged children.

Considerations on optimal fluoride intake using dental fluorosis and dental caries outcomes--a longitudinal study.

OBJECTIVES: The "optimal" intake of fluoride has been widely accepted for decades as between 0.05 and 0.07 mg fluoride per kilogram of body weight (mg F/kg bw) but is based on limited scientific evidence. The purpose of this paper is to present longitudinal fluoride intake data for children free of dental fluorosis in the early-erupting permanent dentition and free of dental caries in both the primary and early-erupting permanent teeth as an estimate of optimal fluoride intake. METHODS: Data on fluoride ingestion were obtained from parents of 602 Iowa Fluoride Study children through periodic questionnaires at the ages of 6 weeks; 3, 6, 9, 12, 16, 20, 24, 28, 32, and 36 months; and then at 6-month intervals thereafter. Estimates of total fluoride intake at each time point were made by summing amounts from water, dentifrice, and supplements, as well as other foods and beverages made with, or containing, water. Caries data were obtained from examinations of children at ages 5 and 9 years, whereas fluorosis data were obtained from examinations of children only at age 9 years. RESULTS: The estimated mean daily fluoride intake for those children with no caries history and no fluorosis at age 9 years was at, or below, 0.05 mg F/kg bw for nearly all time points through the first 48 months of life, and this level declined thereafter. Children with caries had generally slightly less intakes, whereas those with fluorosis generally had slightly higher intakes. CONCLUSIONS: Given the overlap among caries/fluorosis groups in mean fluoride intake and extreme variability in individual fluoride intakes, firmly recommending an "optimal" fluoride intake is problematic.

Relative validity of the Iowa Fluoride Study targeted nutrient semi-quantitative questionnaire and the block kids' food questionnaire for estimating beverage, calcium, and vitamin D intakes by children.

OBJECTIVE: Food frequency questionnaires are commonly developed and subsequently used to investigate relationships between dietary intake and disease outcomes; such tools should be validated in the population of interest. We investigated the relative validities of the Iowa Fluoride Study targeted nutrient semi-quantitative questionnaire and Block Kids' Food Questionnaire in assessing beverage, calcium, and vitamin D intakes using 3-day diaries for reference. DESIGN: Cross-sectional. SUBJECTS: Children who completed Iowa Fluoride Study nutrient questionnaire at age 9.0+/-0.7 years (n=223) and/or the Block Kids' Food Questionnaire at age 8.3+/-0.3 years (n=129) and 3-day diaries during similar time periods. MAIN OUTCOMES: Intakes of beverages, calcium, and vitamin D. STATISTICAL ANALYSES: Spearman correlation coefficients, weighted kappa statistics, and percentages of exact agreement were used to estimate relative validities. RESULTS: Correlations between milk intakes (r=0.572) reported on diaries and the Iowa Fluoride Study nutrient questionnaires were higher than correlations for 100% juice, juice drinks, soda pop, and water (r=0.252 to 0.379). Correlations between milk intakes (r=0.571) and 100% juice intakes (r=0.550) reported on diaries and Block Kids' Food Questionnaires were higher than correlations for other beverages (r=0.223 to 0.326). Correlations with diaries for calcium (r=0.462) and vitamin D (r=0.487) intakes reported on Iowa Fluoride Study nutrient questionnaires were similar to correlations with diaries for calcium (r=0.515) and vitamin D (r=0.512) reported on Block Kids' Food Questionnaires. Weighted kappa statistics were similar between the Iowa Fluoride Study nutrient questionnaires and the Block Kids' Food Questionnaires for milk, 100% juice, and vitamin D, but were higher on the Iowa Fluoride Study nutrient questionnaires than on the Block Kids' Food Questionnaires for calcium. Percentages of exact agreement were higher for calcium, but lower for vitamin D for intakes reported on the Iowa Fluoride Study nutrient questionnaires compared to the Block Kids' Food Questionnaires relative to diaries. CONCLUSIONS: Both the Iowa Fluoride Study nutrient questionnaire and the Block Kids' Food Questionnaire provide reasonable estimates of milk, calcium, and vitamin D intakes when compared to 3-day diaries.

Relative esthetic importance of orthodontic and color abnormalities.

OBJECTIVE: To assess the relative importance of an orthodontic esthetic index, dental fluorosis and nonfluoride opacities, with respect to parents' satisfaction with their children's dental esthetics. MATERIALS AND METHODS: Dental examinations of Iowa Fluoride Study participants assessed fluorosis and nonfluoride opacities in the mixed dentition. Dental casts of 200 randomly selected subjects were scored using the Dental Aesthetic Index (DAI) criteria. Parent satisfaction was assessed via multiple items on a questionnaire. Associations were evaluated using logistic regression. RESULTS: Nineteen percent of parents were somewhat or very dissatisfied with their children's dental esthetics. Overall DAI score was positively associated with dissatisfaction (P < .001), as was fluorosis (P = .003). CONCLUSIONS: In addition to changes related to DAI scores, parent esthetic satisfaction decreased with the presence of fluorosis. Dental professionals should address both the issues of tooth positioning and color aberration with respect to dental esthetics.

The relationships between fluoride intake levels and fluorosis of late-erupting permanent teeth.

OBJECTIVES: To examine the relationships between fluoride intake levels and fluorosis of late-erupting permanent teeth. METHODS: The current study used information collected from 437 children in the longitudinal Iowa Fluoride Study. Participants' fluoride intake information was collected using questionnaires from birth to age 10 years. Estimated mean daily fluoride intake was categorized into low, moderate, and high intake tertiles for each age interval (2-5, 5-8, and 2-8 years). Bivariate analyses were performed to study the relationships between self-reported fluoride intake levels during three age intervals and dental fluorosis. RESULTS: For canines and second molars, the prevalence of mostly mild fluorosis was less than 10% in the lowest fluoride intake tertile and more than 25% in the highest intake tertile. For both first and second premolars, the prevalence in the low and high intake tertiles was approximately 10-15% and 25-40%, respectively. When estimated total daily fluoride intake was 0.04 mg/kg BW during ages 2-8 years, the predicted probability of fluorosis was 16.0%, 20.5%, 21.8%, and 15.4% for canines, 1st and 2nd and premolars and 2nd molars, respectively. We found that an incremental increase in fluoride intake during the age 5- to 8-year interval led to greater odds for development of mostly mild dental fluorosis in late-erupting teeth compared to increases in fluoride intake during other age intervals. CONCLUSIONS: Our results clearly show that dental fluorosis prevalence is closely related to fluoride intake levels and that teeth have greater susceptibility to fluoride intake during certain age intervals.

Associations of fluoride intake with children's cortical bone mineral and strength measures at age 11.

OBJECTIVES: There is strong affinity between fluoride and calcium, and mineralized tissues. Investigations of fluoride and bone health during childhood and adolescence show inconsistent results. This analysis assessed associations between period-specific and cumulative fluoride intakes from birth to age 11, and age 11 cortical bone measures obtained using peripheral quantitative computed tomography (pQCT) of the radius and tibia (n = 424). METHODS: Participants were a cohort recruited from eight Iowa hospitals at birth. Fluoride intakes from water, other beverages, selected foods, dietary supplements, and dentifrice were recorded every 1.5-6 months using detailed questionnaires. Correlations between bone measures (cortical bone mineral content, density, area, and strength) and fluoride intake were determined in bivariate and multivariable analyses adjusting for Tanner stage, weight and height. RESULTS: The majority of associations were weak. For boys, only the positive associations between daily fluoride intakes for 0-3 years and radius and tibia bone mineral content were statistically significant. For girls, the negative correlations of recent daily fluoride intake per kg of body weight from 8.5 to 11 years with radius bone mineral content, area, and strength and tibia strength were statistically significant. No associations between cumulative daily fluoride intakes from birth to 11 years and bone measures were statistically significant. CONCLUSIONS: In this cohort of 11-year-old children, mostly living in optimally fluoridated areas, life-long fluoride intakes from combined sources were weakly associated with tibia and radius cortical pQCT measures.

An investigation of bottled water use and caries in the mixed dentition.

OBJECTIVES: Bottled water consumption in the United States has greatly increased in the past decade. Because the majority of commercial bottled water is low in fluoride, there is the potential for an increase in dental caries. In these secondary data analyses, associations between bottled water use and dental caries were explored. METHODS: Subjects (n = 413) are in the Iowa Fluoride Study, which included dental examinations of the primary (approximately aged 5) and early erupting permanent (approximately aged 9) dentitions by trained dentist examiners. Permanent tooth caries and primary second molar increments were related to bottled water use using logistic and negative binomial regression models. All models were adjusted for age and the frequency of toothbrushing. RESULTS: Bottled water use in this cohort was fairly limited (approximately 10 percent). While bottled water users had significantly lower fluoride intakes, especially fluoride from water, there were no significant differences found in either permanent tooth caries (P = 0.20 and 0.91 for prevalence and D(2+)FS, respectively) or primary second molar caries (P = 0.94 and 0.74 for incidence and d(2+)fs increment, respectively). Results for smooth surfaces differed somewhat from those for pit and fissure surfaces, but neither showed significant differences related to bottled water use. CONCLUSION: While bottled water users had significantly lower fluoride intakes, this study found no conclusive evidence of an association with increased caries. Further study is warranted, preferably using studies designed specifically to address this research question.

Timing of fluoride intake in relation to development of fluorosis on maxillary central incisors.

OBJECTIVES: Several studies have focused on the timing of fluoride intake relative to the development of dental fluorosis. This study reports the relationships of fluoride intake during the first 48 months of life with fluorosis on early-erupting permanent teeth. METHODS: Subjects were followed from birth to 48 months with questionnaires every 3-4 months. Questionnaires gathered data on intakes from water, diet, supplements, and dentifrice to estimate total fluoride intake. Early-erupting permanent teeth of 579 subjects were assessed for fluorosis using the Fluorosis Risk Index (FRI) at approximately age 9. Fluorosis cases were defined as having FRI definitive or severe fluorosis on both maxillary central incisors. Individuals with FRI questionable fluorosis were excluded. The importance of fluoride intake during different time periods was assessed using t-tests and logistic regression. RESULTS: One hundred and thirty-nine (24%) subjects had fluorosis on both maxillary central incisors. Mean fluoride intake per unit body weight (bw) ranged from 0.040 to 0.057 mg/kg bw, with higher intake during earlier time periods and relative stability after 16 months. In bivariate analyses, fluoride intakes during each of the first 4 years were individually significantly related to fluorosis on maxillary central incisors, with the first year most important (P < 0.01), followed by the second (P < 0.01), third (P < 0.01), and fourth year (P = 0.03). Multivariable logistic regression analyses showed that, after controlling only for the first year, the later years individually were still statistically significant. When all four time periods were in the model, the first (P < 0.01) and second years (P = 0.04) were still significant, but the third (P = 0.32) and fourth (P = 0.82) were not. CONCLUSIONS: The first two years of life were most important to fluorosis development in permanent maxillary central incisors; however, this study also suggests the importance of other individual years.

Associations between dental fluorosis of the permanent and primary dentitions.

OBJECTIVES: Relatively little is known about associations between primary and permanent tooth fluorosis. In this study, associations between dental fluorosis of the permanent and primary dentitions were assessed. METHODS: Subjects (n = 601) are in the Iowa Fluoride Study, which included fluorosis examinations of the primary and early-erupting permanent dentitions by trained dentist examiners. Relative risks, correlations, and logistic regression assessed associations between permanent tooth fluorosis and primary molar fluorosis. RESULTS: Ten percent had primary molar fluorosis at age 5; 36% had definitive (mostly mild), 28% questionable, and 36% no permanent incisor fluorosis at age 9. Those with primary molar fluorosis were significantly more likely to have definitive permanent incisor fluorosis (76% vs. 32%), and permanent molar fluorosis (59% vs. 16%). The strong association between primary and permanent tooth fluorosis is independent of level of fluoride intake. CONCLUSIONS: Detection of primary tooth fluorosis in pre-school children should alert clinicians and parents to the high likelihood of subsequent fluorosis in the permanent dentition.

Longitudinal study of non-cavitated carious lesion progression in the primary dentition.

OBJECTIVES: This study reports changes in non-cavitated tooth surface diagnoses after a 4-year period. METHODS: Dental examinations were conducted for Iowa Fluoride Study cohort children who had non-cavitated lesions in the primary dentition and were also examined an average of 4 years later in the mixed dentition. Comparison of fluoride exposures, socioeconomic factors, and beverage consumption patterns were made between children who had lesions progress and those who did not. RESULTS: Of 129 non-cavitated pit and fissure lesions in the first exams, 40 (31%) progressed to either frank decay or filled status, while among 132 noncavitated smooth surface lesions, 7 (5%) were filled and none had frank decay in the second exam. No fluoride, socioeconomic status or beverage variables were significantly associated with lesion progression. CONCLUSIONS: Non-cavitated smooth surface lesions rarely progressed in this age group, but nearly one-third of pit and fissure lesions progressed.

Use of the fluorosis risk index in a cohort study: the Iowa fluoride study.

OBJECTIVES: Several studies have used the Fluorosis Risk Index (FRI) to assess risk factors for dental fluorosis. This study reports fluorosis prevalence estimates in a birth cohort using the FRI in different ways. METHODS: Subjects (n=443) were participants in the Iowa Fluoride Study, a birth cohort study of fluoride exposures and intake, fluorosis, and caries. Early-erupting permanent teeth were assessed for fluorosis using the FRI at approximately age 9. Fluorosis prevalence rates were calculated separately for specific teeth and different combinations of teeth, with varied FRI zones included and using different thresholds. Mean numbers of teeth with fluorosis were calculated. RESULTS: Tooth-specific fluorosis prevalence varied, with maxillary central incisor fluorosis most prevalent and mandibular incisors least affected. Considering three zones of each tooth (cervical zones excluded), 40.6% overall had at least one tooth with mild or more involved fluorosis, 30.2% were questionable fluorosis, and 29.1% had no fluorosis. When only FRI zone I areas were considered, the corresponding percentages were 33.2%, 29.3%, and 37.5%, respectively. When different combinations of teeth were used to define fluorosis cases, the prevalences estimated using three zones were generally 1 to 9 percentage points higher than those estimated from FRI zone 1 only. Most fluorosis was mild, with only 7 individuals (1.6%) having FRI severe fluorosis. CONCLUSIONS: The FRI has advantages for use in analytical epidemiologic studies of dental fluorosis. However, the population prevalence estimates vary, depending on the index and case definition used. Therefore, it is recommended that consideration be given to concurrent use of another index (i.e., TSIF, TF, Dean's) if prevalence estimates are an important study outcome.

Fluoride dentifrice ingestion and fluorosis of the permanent incisors.

BACKGROUND: Fluoride dentifrice is a primary means of preventing childhood caries, but it is also an important risk factor for fluorosis. The authors examine the influence of fluoride dentifrice ingestion on fluorosis of the permanent incisors. METHODS: Participants in the Iowa Fluoride Study received questionnaires at regular intervals concerning fluoride sources. The authors assessed fluorosis using the fluorosis risk index. They estimated daily fluoride ingestion from dentifrice, diet and fluoride supplements and divided the amount by kilograms of body weight. The statistical analysis related fluoride ingestion to fluorosis in the permanent incisors. RESULTS: In bivariate analyses, mild fluorosis was significantly related to ingestion of fluoride dentifrice at ages 24 and 36 months (P = .02 for both). After the authors adjusted for fluoride ingested from dietary sources, logistic regression showed a significant association between fluorosis and dentifrice ingestion at age 24 months (P = .04). CONCLUSIONS: The study results suggest that fluorosis of the permanent incisors is influenced by ingestion of fluoride dentifrice during the first three years of life. Further research is needed to assess total intake of fluoride as a risk factor for fluorosis. CLINICAL IMPLICATIONS: These results support recommendations that young children use only a pea-sized amount of dentifrice. Parents should supervise young children as they brush their teeth with fluoride dentifrice.

Changes in the prevalence of nonnutritive sucking patterns in the first 8 years of life.

INTRODUCTION: The purposes of the study were to determine prospectively the duration of nonnutritive sucking behaviors of children between 1 and 8 years of age and the effect of persistent habits on selected occlusal characteristics in the late deciduous dentition. METHODS: Sucking behavior data were initially collected from 797 children who were followed longitudinally from birth; the data came from periodic questionnaires completed by the parents. In addition, study models were obtained for 372 children at 4 to 5 years of age and assessed for posterior crossbite, anterior open bite, and overjet. The subjects were grouped according to the duration and type of habit (pacifier or digit, for less than 12 months or more than 48 months). Children with nonnutritive sucking of less than 12 months were further grouped according to the duration of breast-feeding. The McNemar nonparametric test was used to compare the changes in the incidence and effect of the habits with time. RESULTS: There was a significant (P = .001) decrease in the incidence of pacifier habits between 1 and 5 years of age, from 40% to 1%. There was a significant (P = .01) decrease in the incidence of digit habits between 1 and 4 years of age, from 31% to 12%. Between 4 and 7 years of age, the decrease in the incidence reached a plateau--ie, the decrease continued but at a slower rate. Between 7 and 8 years of age, there was an additional significant (P = .008) decrease in the incidence of digit habits, but 4% of the children were, to various extents, still sucking fingers. Children who had pacifier or digit habits lasting less than 12 months did not have significantly different occlusal characteristics than children who were breast-fed for 6 to 12 months. Prolonged pacifier and digit habits caused significant changes in the occlusal characteristics in the late deciduous dentition, and the effects of pacifier habits were different from those of digit sucking. CONCLUSIONS: To intercept the development of crossbites and functional shifts, the developing occlusion should be observed in the deciduous dentition in children with prolonged digit or pacifier habits. The transverse occlusal relationship, particularly in pacifier-sucking children, should be evaluated between 2 and 3 years of age. If there are interfering contacts of the deciduous canines, the parents should be instructed to reduce pacifier-sucking time, and appropriate treatment should be rendered, if required.