Biomedical subjects

Steven M Levy

Publications and source records attributed to Steven M Levy.

At least 37 records · Page 2Linked to original sources

PubMed2004

Associations between Intakes of fluoride from beverages during infancy and dental fluorosis of primary teeth.

OBJECTIVE: We describe associations between primary tooth fluorosis status and intakes of beverages and fluoride from these beverages during infancy. METHODS: Subjects (n = 677) are members of the Iowa Fluoride Study, a cohort of young children followed from birth. Food and nutrient intakes were obtained from 3-day diet records. Diets were analyzed at 6 weeks, 3, 6, 9, 12 and 16 months and cumulatively for 6 weeks through 16 months of age. Primary tooth fluorosis was assessed at 4.5-6.9 years of age and defined as present or absent. Multiple logistic regression analyses were used to develop models to predict fluorosis status. RESULTS: Water-based beverage intakes were higher in subjects with fluorosis than in those without. Specifically, higher intakes of water used to reconstitute formulas at 3, 6 and 9 months; any intake of water as a beverage at 16 months; and higher intakes of combined 100% juice and miscellaneous beverages at 16 months were positively associated with fluorosis (p < 0.05). Fluoride intakes from water sources were also higher in subjects with fluorosis than in those without. Specifically, higher intakes of fluoride from water used to reconstitute formulas at 3, 6, 9 and 12 months and for 6 weeks through 16 months, and higher intakes of fluoride from water as a beverage at 16 months and for 6 weeks through 16 months were positively associated with fluorosis (p < 0.05). CONCLUSION: Infant beverages, particularly infant formulas prepared with fluoridated water, can increase the risk of fluorosis in primary teeth.

Beverages↗

PubMed2004

Primary tooth fluorosis and amoxicillin use during infancy.

OBJECTIVE: It has been speculated that amoxicillin use could be associated with enamel defects, but there have been few studies of this possible relationship. This study assessed the association between amoxicillin use during the first year of life and primary tooth fluorosis. METHODS: Subjects (n = 490) were recruited at birth and followed prospectively with a series of questionnaires to gather information on fluoride intake and amoxicillin use. Primary tooth fluorosis was assessed by calibrated examiners at approximately 5 years of age. RESULTS: Amoxicillin use for 6 weeks to 3 months and 3 months to 6 months significantly increased the risk for fluorosis of primary second molars in bivariate analyses. However, after controlling for fluoride intake, the adjusted risks of fluorosis were not significant for amoxicillin use. No other antibiotics were significantly associated with fluorosis in the bivariate analyses. In multivariate analyses with logistic regressions, only fluoride intake was statistically significantly related to fluorosis. CONCLUSION: Fluoride exposure was the sole predictor of primary tooth fluorosis in a multivariate model. However, bivariate results suggest that amoxicillin could play a contributing role in the development of primary tooth fluorosis, especially for children exposed to lower levels of fluoride. An investigation of the relationship between amoxicillin intake and fluorosis of permanent teeth is warranted.

Age Factors↗

PubMed2004

The association between environmental tobacco smoke and primary tooth caries.

OBJECTIVE: Environmental tobacco smoke (ETS) has been associated with a number of negative health outcomes for exposed children. The goal of this study was to assess the association between ETS and dental caries in a pediatric population. METHODS: This study included 637 Iowa Fluoride Study children whose parents provided socioeconomic information, completed at least three questionnaires during the first year of life, and had a primary dentition exam at age 4-7 years. Households reporting in all questionnaires that someone smoked in the home were categorized as regularly smoking homes. Socioeconomic status (SES) was divided into three groups (low, middle, and high) based on family income and mother's education. Children were classified as having caries if any of the primary teeth had fillings or cavitated lesions at the primary dentition exam. RESULTS: Overall, children residing in regularly smoking homes had a higher prevalence of caries. For the middle SES group and overall, the children from smoking homes had a significantly higher prevalence of caries compared to nonregular/nonsmoking homes (52% vs 24%, P=.05 and 44% vs 25%, P=.002, respectively). After adjusting for age, SES, toothbrushing frequency, total ingested fluoride, and combined intake of soda pop and powdered drink beverages, the relationship of smoking and caries still remained significant (odds ratio [OR]=3.38; P=.001). CONCLUSIONS: Environmental tobacco smoke was associated with an increased risk of caries among children.

Age Factors↗

PubMed2004

Seasonal variation in fluoride intake: the Iowa fluoride study.

OBJECTIVES: Although patterns of fluid intake change seasonally, little is known about how fluoride intake varies by season. Since even short-term increases in fluoride intake could potentially lead to more dental fluorosis, it is valuable to assess the degree of seasonal variation to determine if it increases fluoride intake to levels that could be considered a concern in young children. METHODS: Questionnaires were mailed periodically to participants in the Iowa Fluoride Study beginning at 6 weeks of age and continuing for a number of years. Parents recorded the date; child's weight; estimates of the amounts of water and other beverages that their child consumed per week; the type and amount of any fluoride supplements used; and the type, amount, and frequency of dentifrice used, with an estimate of the proportion of dentifrice that was swallowed. Documented water fluoride levels from municipal sources and assay of individual sources were linked to water intake amounts. Total fluoride intake per kg body weight was estimated from water, other beverages, fluoride supplements, and ingested dentifrice. Generalized linear models compared temperature-related and seasonal effects after adjusting for the child's age. RESULTS: Separate analyses for ages 0-12 months and 12-72 months showed different results. Children younger than 12 months of age did not exhibit significant seasonal or temperature-related variation in any of the components of fluoride intake. Children aged 12-72 months had higher fluoride intake (mg F/kg bw) from beverages in summer (P<.05), and fluoride intake from beverages increased with monthly temperature (P<.001). CONCLUSIONS: Fluoride intake from beverages for children aged 12-72 months is slightly higher in the summer and increases with mean monthly temperature. Fluoride intake from supplements and dentifrice did not change significantly with either season or temperature.

Age Factors↗

PubMed2004

Everyday activity predicts bone geometry in children: the iowa bone development study.

PURPOSE: Bone adapts to changing mechanical loads by altering the structure appropriately. These adaptations should be evident in the bone cross-sectional area (CSA) and section modulus (Z), indices of axial and bending strength, respectively. In this cross-sectional study, we investigated associations between physical activity, CSA, and Z in 467 young children (mean age 5.2 yr). We also examined whether lean tissue mass, which is predominantly muscle, mediates the relationship between physical activity and bone structural measures. METHODS: Physical activity was assessed using accelerometry and questionnaire. Proximal femur measures of the neck, intertrochanteric, and shaft CSA (cm) and Z (cm) were derived from dual-energy x-ray absorptiometry (DXA) scans using the Hip Structure Analysis program. Total body lean mass (kg) was also measured using DXA. RESULTS: Boys were more physically active than girls. Boys also had greater CSA, Z, and lean mass than girls. At each region, time spent in vigorous activity was positively and consistently associated with CSA and Z in boys and girls (r = 0.19 to 0.32). After adjustment for age, body mass, and height, vigorous activity explained, on average, 6.9% of the variability in CSA and Z. With additional adjustment for lean mass, vigorous activity explained 3.7% of the remaining variability in CSA and Z. CONCLUSION: This study demonstrates that everyday amounts of physical activity in healthy, normal children are associated with bone geometry and that differences in lean mass explain some, but not all, of this association. This suggests that, even in young, nonathletic children, bone may adapt to physical activity by structurally remodeling.

Anthropometry↗

PubMed2004

Perceptions of desirable tooth color among parents, dentists and children.

BACKGROUND: As part of a large-scale fluoridation cessation study, standardized examiners assessed 8,281 school-aged children for dental fluorosis using the Thylstrup Fejerskov index, or TFI, in which scores range from 0 (no fluorosis) to 9 (severe loss of enamel with change of anatomical appearance). METHODS: Dentists, parents and children were asked to respond to a statement, "The color of these teeth (mine or my child's) is pleasing and looks nice." Agreement or disagreement with the statement was indicated on a five-level scale, with a rating of 1 representing total agreement with the reference statement. The authors used repeated-measures analysis of variance to ascertain differences in satisfaction with the esthetic appearance of the subject's tooth color across dentists', parents' and subjects' perceptions. RESULTS: Girls were more critical of their tooth color than were boys; however, parents and dentists were more critical of boys' tooth color than of girls'. While younger subjects were more critical than older subjects, parents of younger subjects were less critical than those of older subjects. Dentists' ratings were not significantly associated with subjects' age group. Subjects with a TFI score of 1 or 2 were not significantly more critical than subjects with a TFI score of 0, while those with a TFI score of 3 of higher were. Similarly, only parents of subjects with a TFI score of 3 of higher had significantly different ratings. CONCLUSIONS: The three stakeholders in the esthetic treatment of children-parents, dentists and patients-appear to see the potential outcome of such treatment differently. CLINICAL IMPLICATIONS: Dentists should ensure that parents and children agree about the course of treatment, the rationale for undertaking it and the results that could reasonably be expected.

Adolescent↗

PubMed2003

Gene polymorphisms, bone mineral density and bone mineral content in young children: the Iowa Bone Development Study.

We examined the association of candidate gene polymorphisms with bone mineral density (BMD) and bone mineral content (BMC) in a cohort of 428 healthy non-Hispanic white children participating in the Iowa Bone Development Study, a longitudinal study of determinants of bone accrual in childhood. BMD and BMC measurements of the hip, spine and whole body were made using a Hologic 2000 Plus densitometer in 228 girls and 200 boys ages 4.5-6.5 years. Genotypes at 14 loci representing eight candidate genes [type I collagen genes (COL1A1 and COL1A2), osteocalcin, osteonectin, osteopontin, vitamin D receptor (VDR), estrogen receptor (ER), androgen receptor (AR)] were determined. Gender-specific and gender-combined prediction models for bone measures that included age, weight, height (and gender) were developed using multiple linear regression analysis. COL1A2 and osteocalcin genotypes were identified as having the strongest and most consistent association with BMD/BMC measures. Osteonectin, osteopontin and VDR translation initiation site polymorphisms were associated with some individual bone measures, but none of the associations was as consistent as those identified for the COL1A2 and osteocalcin genes. No association was identified with COL1A1 (RsaI and Sp1), VDR (BsmI) and ER polymorphisms (PvuII, XbaI, TA) and BMD/BMC. However, we identified significant gene-by-gene interaction effects involving the ER and both VDR and osteocalcin, which were associated with BMD/BMC. Our data suggest that genetic variation at multiple genetic loci is important in bone accrual in children. Moreover, the combination of genotypes as several loci may be as important as a single genotype for determining BMD and BMC.

Anthropometry↗

PubMed2003

Patterns of beverage consumption during the transition stage of infant nutrition.

We describe beverage intakes during the transition stage of infant nutrition. Mean daily intakes of infant formula, cow's milk, combined juice and juice drinks, water, and other beverages estimated from a beverage frequency questionnaire were analyzed cross-sectionally at ages six through 24 months (n=701). Most children (97%) consumed human milk, infant formula, or cows' milk at each age studied. Mean daily intakes of combined infant formula and cows' milk declined from 28.0 oz at six months to 12.1 oz at 24 months. The percentage of children consuming juice and/or juice drinks increased with age, and mean daily consumption peaked at 9.1 oz at 20 months. Combined formula and cows' milk intakes were inversely associated with juice and juice drink intakes at all ages (-0.25 < r < 0; P<.01). Juice and juice drinks appear to replace formula and milk intakes during the transition stage of infant nutrition.

Animals↗

PubMed2003

Current and future role of fluoride in nutrition.

Fluoride continues to be the cornerstone of dental caries prevention in North America and throughout the world, and there are a variety of sources of fluoride that may contribute to the dietary intakes of fluoride. Although the severe effect of chronic exposures to high levels of fluoride--skeletal fluorosis--is extremely rare in North America, dental fluorosis has become more prevalent. To address the increase in dental fluorosis prevalence, recommendations have been made to reduce fluoride ingestion early in life. These recommendations have included the introduction of lower concentration fluoride dentifrice for use by young children, labeling of the fluoride concentration of bottled water, and revised fluoride supplement guidelines to reduce or eliminate their use. Because our knowledge is incomplete regarding the amount, duration, and timing of fluoride ingestion that can result in dental fluorosis, however, further research is clearly needed before definitive recommendations can be made regarding the use of fluorides, including recommended intakes of fluoride in the diet.

Dental Caries↗

PubMed2003

Medically administered antibiotics, dietary habits, fluoride intake and dental caries experience in the primary dentition.

OBJECTIVES: Dental caries continues to be a major public health problem in the US and other nations, particularly among younger children. Unfortunately, understanding of factors contributing to caries in this age group is incomplete and further studies are necessary. The purpose of this study was to assess factors related to extensive caries experience among children aged 4-7 years, including antibiotic use, dietary patterns, fluoride intakes, and tooth brushing habits. METHODS: The case-control study was nested within a longitudinal cohort study of children's oral health. The larger cohort study collected data on fluoride intakes and behavioral factors, including antibiotic use and dietary patterns of children periodically from birth. A single dental examination was completed for each child at a time between the ages of 4-7 years. A case-control design was used to compare children with severe caries experience (6 or greater dmfs) to those with no caries experience. Cases (n = 39) included all who met the criteria and had sufficient longitudinal data (n = 39) while a control group was selected to have comparable mean age, exam dates, and an equal number of boys and girls. RESULTS: Backward elimination logistic regression controlling for demographic variables showed severe caries experience to be related to greater regular pop/other sugared beverage intake, greater frequency of starch foods, and greater frequency of eating occasions. Mother's education and fluoride intake from water were inversely related to severe caries experience. Antibiotic use was generally higher in the control group, but was not significantly different than in the severe caries group. CONCLUSIONS: Although we cannot rule out the possibility that antibiotics may be associated with increased or decreased caries risk, our data suggest that they play only a minor role in caries prevention compared to fluoride. Dietary sugar continues to be a significant risk factor for caries in the primary dentition.

Anti-Bacterial Agents↗

PubMed2003

Relative validation of a beverage frequency questionnaire in children ages 6 months through 5 years using 3-day food and beverage diaries.

OBJECTIVE: To determine the relative validity of a quantitative beverage frequency questionnaire in assessing beverage, calcium, and vitamin D intakes using 3-day food diaries for reference. DESIGN: Parents were asked to complete questionnaires for the preceding week and diaries for the following week for their children. Calcium and vitamin D intakes were estimated from human milk, infant formulas, and cow's milk ("beverages") for questionnaires and diaries and from "all foods and beverages" for diaries. Data collected at 6 and 12 months and 3 and 5 years of age as part of the Iowa Fluoride Study (N=700) were analyzed cross-sectionally. SUBJECTS: Children (N=240); 60 randomly selected from each quartile of energy intake at 6 months of age. STATISTICAL ANALYSES: Spearman correlation coefficients, weighted kappa statistics, and percentages of exact agreement were used to assess associations between tools. RESULTS: Correlations between mean daily beverage intakes estimated from questionnaires and diaries ranged from 0.95-0.99 for human milk, 0.84-0.85 for infant formula, 0.63-0.86 for cow's milk, 0.54-0.69 for juice/drinks, 0.26-0.59 for liquid soft drinks, 0.35-0.74 for powdered soft drinks and 0.54-0.70 for water. Correlations between mean daily nutrient intakes estimated from questionnaires and diaries "beverages" ranged from 0.64-0.74 for calcium and 0.60-0.80 for vitamin D; and between questionnaires and diaries "all foods and beverages" ranged from 0.41-0.63 for calcium and 0.43-0.80 for vitamin D. APPLICATIONS: A quantitative beverage frequency questionnaire can provide a relative estimate of beverage, calcium, and vitamin D intakes.

Animals↗

PubMed2003

Patterns of fluoride intake from 36 to 72 months of age.

OBJECTIVES: This paper reports on estimated daily fluoride intake from water by itself, beverages, selected foods, dentifrice, and dietary supplements, both individually and combined (mg and mg F/kg bw), among 785 children in the Iowa Fluoride Study from 36 to 72 months of age. METHODS: Children were recruited in 1992-95, with questionnaires sent at four- to six-month intervals. Dietary fluoride intake estimates used community and individual water fluoride levels and average fluoride levels of beverages and foods prepared with water. Descriptive statistics and generalized linear models (GLM) assessed levels and associations with demographic factors. RESULTS: There was substantial variation in fluoride intake, with some individuals' intakes greatly exceeding the means. Daily water fluoride intake estimates (in mg) increased with age, fluoride intake from other beverages and dentifrice both decreased slightly, and combined intake was quite consistent. For combined intake per unit body weight (mg F/kg bw), there was a steady decline with age. Therefore, the percentages with estimated intake exceeding possible thresholds for dental fluorosis also declined with age. CONCLUSIONS: Daily mean fluoride intakes from single and combined sources are relatively stable from 36-72 months of age among these children.

Beverages↗

PubMed2003

Explorer probing of root caries lesions: an in vitro study.

Probing with a dental explorer is the preferred method of root caries diagnoses. However, studies suggest that use of a dental explorer in coronal caries detection may damage tooth structure. This pilot study investigated the effect of probing on remineralization of root surface lesions in vitro. Root-surface lesions were created on 10 extracted teeth by exposing them to a demineralizing solution for 21 days. One side of each lesion was then randomly selected and probed with an explorer, while the other side was not probed. The teeth then were placed in a remineralizing solution containing 10 parts per million (ppm) fluoride for 21 days. Of the 9 teeth with usable sections, all showed frank evidence of defects on the probed halves. Sites of remineralization were seen in the non-probed halves and adjacent to the probed defects, but not within or at the base of these defects. These results suggest that probing of root surfaces may create defects that do not fully remineralize.

Cariostatic Agents↗

PubMed2003

The prevalence of periodontal disease measures in elderly adults, aged 79 and older.

From 1996-98, we examined 449 adults (mean age 85 years) from the 1982 Iowa 65+ Rural Health Study, in the field using headlight, mirror, and periodontal probe. Ninety-six of the 342 dentate subjects were excluded from the follow-up examination due to contraindications to probing, and 10 could not be assessed due to refusals, fatigue or other reasons. For all remaining subjects (n=236), attachment loss, defined as recession plus probing depth, was determined at four sites per tooth. Ninety-one percent of the subjects had at least one site with 4+ mm of attachment loss, 45% had one or more sites with attachment loss of 6+ mm, and 15% had 8+ mm of attachment loss. Moderate periodontal disease is prevalent among very old dentate adults while advanced periodontal disease is much less prevalent, suggesting that most periodontal treatment needed by this age group can be provided by general dentists and dental hygienists rather than periodontists.

Aged↗

PubMed2003

Dental caries and beverage consumption in young children.

OBJECTIVE: Dental caries is a common, chronic disease of childhood. The impact of contemporary changes in beverage patterns, specifically decreased milk intakes and increased 100% juice and soda pop intakes, on dental caries in young children is unknown. We describe associations among caries experience and intakes of dairy foods, sugared beverages, and nutrients and overall diet quality in young children. METHODS: Subjects (n = 642) are members of the Iowa Fluoride Study, a cohort followed from birth. Food and nutrient intakes were obtained from 3-day diet records analyzed at 1 (n = 636), 2 (n = 525), 3 (n = 441), 4 (n = 410), and 5 (n = 417) years and cumulatively for 1 through 5 (n = 396) years of age. Diet quality was defined by nutrient adequacy ratios (NARs) and calculated as the ratio of nutrient intake to Recommended Dietary Allowance/Adequate Intake. Caries were identified during dental examinations by 2 trained and calibrated dentists at 4 to 7 years of age. Examinations were visual, but a dental explorer was used to confirm questionable findings. Caries experience was assessed at both the tooth and the surface levels. Data were analyzed using SAS. The Wilcoxon rank sum test was used to compare food intakes, nutrient intakes, and NARs of subjects with and without caries experience. Logistic and Tobit regression analyses were used to identify associations among diet variables and caries experience and to develop models to predict caries experience. Not all relationships between food intakes and NARs and caries experience were linear; therefore, categorical variables were used to develop models to predict caries experience. Food and beverage intakes were categorized as none, low, and high intakes, and NARs were categorized as inadequate, low adequate, and high adequate. RESULTS: Subjects with caries had lower median intakes of milk at 2 and 3 years of age than subjects without caries. Subjects with caries had higher median intakes of regular (sugared) soda pop at 2, 3, 4, and 5 years and for 1 through 5 years; regular beverages from powder at 1, 4, and 5 years and for 1 through 5 years; and total sugared beverages at 4 and 5 years than subjects without caries. Logistic regression models were developed for exposure variables at 1, 2, 3, 4, and 5 years and for 1 through 5 years to predict any caries experience at 4 to 7 years of age. Age at dental examination was retained in models at all ages. Children with 0 intake (vs low and high intakes) of regular beverages from powder at 1 year, regular soda pop at 2 and 3 years, and sugar-free beverages from powder at 5 years had a decreased risk of caries experience. High intakes of regular beverages from powder at 4 and 5 years and for 1 through 5 years and regular soda pop at 5 years and for 1 through 5 years were associated with significantly increased odds of caries experience relative to subjects with none or low intakes. Low (vs none or high) intakes of 100% juice at 5 years were associated with decreased caries experience. In general, inadequate intakes (vs low adequate or high adequate intakes) of nutrients (eg, riboflavin, copper, vitamin D, vitamin B(12)) were associated with increased caries experience and low adequate intakes (vs inadequate or high adequate intakes) of nutrients (eg, vitamin B(12), vitamin C) were associated with decreased caries experience. An exception was vitamin E; either low or high adequate intakes were associated with increased caries experience at various ages. Multivariable Tobit regression models were developed for 1- through 5-year exposure variables to predict the number of tooth surfaces with caries experience at 4 to 7 years of age. Age at dental examination showed a significant positive association and fluoride exposure showed a significant negative association with the number of tooth surfaces with caries experience in the final model. Low intakes of nonmilk dairy foods (vs high intakes; all subjects had some nonmilk dairy intakes) and high adequate intakes of vitamin C (vs inadequate and low adequate intakes) were associated with fewer tooth surfaces having caries experience. High intakes of regular soda pop (vs none and low intakes) were associated with more tooth surfaces having caries experience. CONCLUSIONS: Results of our study suggest that contemporary changes in beverage patterns, particularly the increase in soda pop consumption, have the potential to increase dental caries rates in children. Consumption of regular soda pop, regular powdered beverages, and, to a lesser extent, 100% juice was associated with increased caries risk. Milk had a neutral association with caries. Associations between different types of sugared beverages and caries experience were not equivalent, which could be attributable to the different sugar compositions of the beverages or different roles in the diet. Our data support contemporary dietary guidelines for children: consume 2 or more servings of dairy foods daily, limit intake of 100% juice to 4 to 6 oz daily, and restrict other sugared beverages to occasional use. Pediatricians, pediatric nurse practitioners, and dietitians are in a position to support pediatric dentists in providing preventive guidance to parents of young children.

Carbonated Beverages↗

PubMed2003

An update on fluorides and fluorosis.

Decisions concerning use of fluoride in its many forms for caries prevention are more complicated now than in the past because of the need to balance these benefits with the risks of dental fluorosis. This article reviews pertinent literature concerning dental fluorosis (definition, appearance, prevalence), pre- and post-eruptive use of fluoride, esthetic perceptions of dental fluorosis, fluoride levels of beverages and foods, the Iowa Fluoride Study, and the U.S. Centers for Disease Control and Prevention's "Recommendations for Using Fluoride to Prevent and Control Dental Caries in the United States." Water fluoridation and use of fluoride dentifrice are the most efficient and cost-effective ways to prevent dental caries; other modalities should be targeted toward high-risk individuals.

Canada↗

PubMed2002

Fatness, physical activity, and television viewing in children during the adiposity rebound period: the Iowa Bone Development Study.

BACKGROUND: Understanding the determinants of adiposity in young children may be particularly critical for preventing adult obesity since the age at which body fatness reaches a postinfancy low point (typically 4-6 years) is inversely associated with obesity later in life. METHODS; We examined cross-sectional associations among fatness, leanness, and physical activity in 467 children (range 4-6 years). Activity was measured using accelerometry and parental report of children's television (TV) viewing. Dual energy X-ray absorptiometry was used to quantify body composition. RESULTS: Minutes spent in vigorous activity and TV viewing were the variables most consistently and most highly associated with adiposity. Children in the lowest quartile for vigorous activity had on average (absolute) body fat percentages that were 4% greater than those children in the highest quartile for vigorous activity. Body fat percentages for children in the highest category for TV viewing were on average 3% greater than those children who watched the least amount of TV. CONCLUSIONS: Low levels of vigorous physical activity and high levels of TV viewing are associated with fatness in young children during the adiposity rebound period. This suggests that increasing children's active play may be important in preventing obesity later in life.

Absorptiometry, Photon↗

PubMed2002

Primary tooth fluorosis and fluoride intake during the first year of life.

OBJECTIVES: Few studies in North America have assessed dental fluorosis of the primary dentition and few, if any, anywhere have assessed the relative importance in fluorosis etiology of fluoride intake during different time periods or from multiple sources. The purpose of this paper is to report on analyses relating estimated prenatal fluoride intake and fluoride intake during different parts of the first year of life to primary tooth fluorosis. METHODS: As part of The Iowa Fluoride Study, subjects were recruited at birth and studied longitudinally. Trained examiners assessed dental fluorosis for children aged 4-7 years using the Tooth Surface Index of Fluorosis (TSIF) adapted for the primary dentition. Detailed parent questionnaires at childbirth were used to estimate prenatal fluoride intake and questionnaires sent at 6 weeks and 3, 6, 9, and 12 months were used to estimate fluoride intake during the first year of life (combined fluoride intake from water, food and beverage, supplements, and dentifrice). There were 504 children with prenatal and at least four of the five postnatal responses with complete data. RESULTS: Fluorosis prevalence was 12.1%, occurring primarily on the second primary molars. Receiver operating characteristic (ROC) curves and logistic regression were used to assess the importance of different time periods' fluoride intake. In bivariate analyses, fluoride intake during each time interval was individually significantly related to fluorosis occurrence. For multivariate analyses, the period from 6 to 9 months was most important individually (P = 0.0001), and no other period was jointly statistically significant. CONCLUSIONS: Results suggest that the middle of the first year of life is most important in fluorosis etiology for the primary dentition in this setting.

Area Under Curve↗