Shed Deciduous Teeth Research Articles

Deciduous teeth from the New Hampshire birth cohort study: Early life environmental and dietary predictors of dentin elements

BackgroundSparse research exists on predictors of element concentrations measured in deciduous teeth. ObjectiveTo estimate associations between maternal/child characteristics, elements measured in home tap water during pregnancy and element concentrations in the dentin of shed deciduous teeth. MethodsOur analysis included 152 pregnant person-infant dyads followed from the second trimester through the end of the first postnatal year from the New Hampshire Birth Cohort Study. During pregnancy and early infancy, we collected dietary and sociodemographic information via surveys, measured elements in home tap water, and later collected naturally exfoliated teeth from child participants. We measured longitudinal deposition of elements in dentin using LA-ICP-MS. Multivariable linear mixed models were used to estimate associations between predictors and dentin element concentrations. ResultsWe measured 12 elements in dentin including those previously reported (Ba, Mn, Pb, Sr, Zn) and less frequently reported (Al, As, Cd, Cu, Hg, Li, and W). A doubling of Pb or Sr concentrations in water was associated with higher dentin Pb or Sr respectively in prenatally formed [9% (95%CI: 3%, 15%); 3% (1%, 6%)] and postnatally formed [10% (2%, 19%); 6% (2%, 10%)] dentin. Formula feeding from birth to 6 weeks or 6 weeks to 4 months was associated with higher element concentrations in postnatal dentin within the given time period as compared to exclusive human milk feeding: Sr: 6 weeks: 61% (36%, 90%) and 4 months: 85% (54%, 121%); Ba: 6 weeks: 35% (3.3%, 77%) and 4 months: 42% (10%, 83%); and Li: 6 weeks: 61% (33%, 95%) and 4 months: 58% (31%, 90%). SignificanceThese findings offer insights into predictors of dentin elements and potential confounders in exposure-health outcome relationships during critical developmental periods.

Sheep and goat management in the Early Neolithic in the Zagros region (8000–5000 BC): New zooarchaeological and isotopic evidence from Ganj Dareh, Bestansur and Jarmo

The transition from hunter gathering to farming is one of the most important episodes in the history of humankind. Considerable evidence indicates that this shift was a slow, complex, highly localized process, which took place in multiple places in Southwest Asia independently, from around 9500 BC. Caprines were arguably the first domesticated livestock, brought under human control during a process that began in the 9th millennium BC in a region extending from south-eastern Turkey to north-western Iran. In this research we integrate zooarchaeological analysis with stable isotopic data of faunal remains from three key Early Neolithic sites in the Eastern Fertile Crescent: Ganj Dareh (ca. 8000 BC), Bestansur (ca. 7800–7000 BC) and Jarmo (ca. 7000–5000 BC).While some form of goat management seemed to have been practiced at Bestansur, based on spherulites, dung and shed deciduous teeth, no evidence has been found for winter foddering or transhumance practices. At Ganj Dareh goat were managed, and might have been foddered during the winter or vertical transhumance might have taken place. At Pottery Neolithic Jarmo both sheep and goat were managed and they were possibly brought to higher elevations during the summer months or foddered during winter. This research has supported the idea that already during early stages of goat management, humans kept a high degree of control over the population.

Evaluation of blood and tooth element status in asthma cases: a preliminary case\u2013control study

BackgroundAsthma is a common respiratory disorder; some data were present on the correlation between increased levels of some elements and the risk of asthma development. It was aimed to evaluate the levels of 13 selected blood and tooth elements (magnesium, phosphorus, calcium, chromium, manganese, iron, copper, zinc, strontium, molybdenum, cadmium, lead, mercury) in a well-controlled asthma group and the control group.MethodsDuring the study period, 17 asthma patients and 26 age and gender-matched healthy children donated shed deciduous teeth having neither decay nor filling and enrolled for the study. The element levels in blood and teeth matrixes were analyzed with inductively coupled plasma mass spectrometry. Differences in blood and tooth elements in groups were evaluated with generalized linear models after adjusting confounding factors.ResultsAfter adjusting the child’s “z scores of body mass index for age”, history of iron deficiency anemia, and status of parental smoking, the generalized linear model revealed significantly lower tooth magnesium levels, lower blood zinc levels, and lower blood zinc/copper ratio in the asthma group than the control group (p = 0.042, p = 0.034, p = 0.002, respectively). Other studied elements for tooth and blood matrixes were similar in groups.ConclusionOur study revealed some differences in tooth and blood element levels in the asthma group. Further studies on zinc and magnesium levels of severe asthma cases are necessary for the interpretation of the results.

The Truth Fairy Project

TPS 621: Exposure to metals, Johan Friso Foyer, Floor 1, August 26, 2019, 3:00 PM - 4:30 PM Background/ Aim: Lead (Pb) is a potent neurotoxicant with no safe level of exposure. Elevated levels of Pb and arsenic (As) are found near facilities that recycle lead-acid batteries in the United States. Assessing historical exposure to toxic chemicals, especially in situations of a specific industrial source of pollution affecting a community, is critical for informing appropriate public health and policy responses. We describe a community-driven approach to integrate retrospective environmental hazard exposure assessment with community organizing to address concerns about the extent of exposure to toxic metals in a predominantly working-class, Latinx community living near a now-closed lead-acid battery smelter facility. Methods: In this pilot study coined the “Truth Fairy” Project, 50 shed deciduous teeth from 43 children living their entire lives within 2 miles of the smelter to understand in retrospective exposure to toxic metals using community-driven research approach. Concentrations of Pb and As in teeth were assessed using laser-ablation-inductively coupled plasma-mass spectrometry. Soil Pb concentrations were determined using spatial kriging of surface soil measurements. Results: The mean prenatal calcium normalized Pb concentration in teeth samples (reported as a ratio 208Pb:43Ca), was 4.104 x 10-4 (SD 4.123 x 10-4), and the mean postnatal 208Pb:43Ca level was 4.109 x 10-4 (SD 3.369 x 10-4). Adjusted for maternal education and analytical batch, we observe positive significant relationship between prenatal teeth Pb per 100 ppm increase in soil Pb (β=3.48, 95% CI 1.11, 5.86), indicating higher Pb exposures near the site of industrial exposure. Study results were disseminated to the community using infographics. Conclusions: The Truth Fairy study provides insights into assessing retrospective exposure to toxic metals among children living near legacy sources. This project integrated community mobilization with empirical research, informing residents about toxic metal exposures and improving the community’s capacity to respond to a public health crisis.

Lead and Arsenic in Shed Deciduous Teeth of Children Living Near a Lead-Acid Battery Smelter.

Lead (Pb) is a potent neurotoxicant with no safe level of exposure. Elevated levels of Pb and arsenic (As) are found in the air and soil near facilities that recycle lead-acid batteries in the United States. In urban Los Angeles County, California, a facility processed ∼11 million batteries per year and operated for decades without proper environmental review. Measuring Pb and As in shed deciduous teeth is a promising technique to assess prenatal and early life exposure. In this pilot study coined the "Truth Fairy" Project, 50 shed deciduous teeth from 43 children living their entire lives within 2 miles of the smelter were analyzed to understand retrospective exposure to toxic metals using a community-driven research approach. Concentrations of Pb and As in teeth were assessed using laser-ablation-inductively coupled plasma-mass spectrometry. Soil Pb concentrations were determined using spatial kriging of surface soil measurements. The mean prenatal calcium normalized Pb levels in teeth samples (reported as a ratio 208Pb:43Ca) was 4.104 × 10-4 (SD 4.123 × 10-4), and the mean postnatal 208Pb:43Ca level was 4.109 × 10-4 (SD 3.369 × 10-4). Adjusted for maternal education and batch, we observe positive significant relationship between prenatal teeth Pb per 100 ppm increase in soil Pb (β = 3.48, 95% CI 1.11, 5.86). The Truth Fairy study suggests prenatal and early life exposure to toxic metals is associated with legacy soil contamination in an urban community near a smelter.

Dental lead levels in children from two different urban and suburban areas of Turkey

The lead content of shed primary teeth has proved to be a reliable measure of cumulative lead exposure in children as it is an indicator of the degree of exposure over several years, from in utero life to loss of the tooth. Totally 297 shed deciduous teeth were collected from 263 children between ages 4 and 15 to determine the level of lead exposure in Ankara and Balıkesir in Turkey. Ankara is the capital of Turkey and characterized by heavy traffic and high air pollution. On the other hand, Balıkesir has less traffic. Balıkesir-Centre (R) had the highest mean (SD) lead level (1.77±1.03 μg/g) whereas Ankara-Centre (U) had the lowest level (1.30±0.59 μg/g). We could not observe a statistically significant difference between urban and suburban regions (Table 1), and in terms of type of tooth, incisors had a statistically significant higher lead level than canines and molars ( p<0.05, Table 2). No difference was observed between boys and girls and the accumulation of lead in teeth ( p<0.05, Table 3).

Delayed visual maturation and lead pollution

Three children were born in the Broken Hill Australia lead mining community with delayed visual maturation of the optic nerve (blindness) within a period of 19 months. Because of the association with the lead pollution, the delayed visual maturation was attributed to lead exposure of the fetus during pregnancy. Lead isotopic analyses of the shed deciduous teeth from the three children demonstrate that they were not exposed to increased levels of lead from a mining or any other source during pregnancy and the etiology of the delayed visual maturation must be sought elsewhere.

Deciduous Teeth in Tuberous Sclerosis

The diagnostic significance of enamel pits in shed deciduous teeth from 20 patients with tuberous sclerosis was investigated at the University of Copenhagen, Denmark.

Contributions of risk factors to elevated blood and dentine lead levels in preschool children

The relationship between blood lead level (PbB) and an array of socio-demographic, behavioral, caregiving and environmental risk factors was investigated in a cohort of socioeconomically disadvantaged urban children at ages 2, 3 and 4 years and 10 months. The risk factors were also related to dentine lead level (PbD) from shed deciduous teeth. Strong persistent pairwise relationships with PbB and PbD were observed for maternal IQ, parental education, examiner ratings of the condition and cleanliness of the physical environment, and the HOME scale, which assesses the quality of the caretaking environment. The association between dirt pica and PbB was strong at 2 years ( r = 0.30), but was less pronounced in subsequent assessments as the prevalence of pica decreased. Insignificant or weak relationships were found for maternal assessments of paint-and-plaster peeling in the home and non-dirt pica. The HOME scale and the ratings of the condition of the physical environment were significantly related to PbB and PbD even after adjustment for socio-demographic factors. These two measures were also strongly related to an array of developmental outcomes. The results indicate that statistical adjustment specifically for the quality of the caretaking environment can lead to substantial reductions in estimates of adverse lead effects.

Lessons from a Danish study on neuropsychological impairment related to lead exposure.

Serious problems emerge when evaluating evidence on lead neurotoxicity in children. The extent of these problems and ways to control them were explored in a study of 1291 children from the first class in the schools of Aarhus municipality, Denmark. The lead retention in circumpulpal dentin in shed deciduous teeth was used as an indicator of cumulated lead exposure; it correlated most strongly with traffic density at the residence of each family and at the day-care institutions. In a nested case-control group selected on the basis of dentin lead concentrations, 29 of 200 children had encountered obstetrical complications and other medical risks for neurobehavioral dysfunction; these children primarily belonged to the low-lead group. As lead-related neurobehavioral effects are nonspecific, inclusion of these children in the data analysis would therefore have distorted the results toward the null hypothesis. Children from the high-lead group who had experienced neonatal jaundice showed impaired performance when compared to other high-lead children; this finding may suggest a synergistic effect. The Bender gestalt test scored by the Göttingen system was the test that was most sensitive to lead exposure. The conclusion that neurobehavioral effects can be caused by the relatively low lead exposures in Denmark may not be surprising, as current exposures to this toxic metal greatly exceed the prepollution levels to which the human body originally adapted.

Lessons from a Danish Study on Neuropsychological Impairment Related to Lead Exposure

Serious problems emerge when evaluating evidence on lead neurotoxicity in children. The extent of these problems and ways to control them were explored in a study of 1291 children from the first class in the schools of Aarhus municipality, Denmark. The lead retention in circumpulpal dentin in shed deciduous teeth was used as an indicator of cumulated lead exposure; it correlated most strongly with traffic density at the residence of each family and at the day-care institutions. In a nested case-control group selected on the basis of dentin lead concentrations, 29 of 200 children had encountered obstetrical complications and other medical risks for neurobehavioral dysfunction; these children primarily belonged to the low-lead group. As lead-related neurobehavioral effects are nonspecific, inclusion of these children in the data analysis would therefore have distorted the results toward the null hypothesis. Children from the high-lead group who had experienced neonatal jaundice showed impaired performance when compared to other high-lead children; this finding may suggest a synergistic effect. The Bender gestalt test scored by the Gottingen system was the test that was most sensitive to lead exposure. The conclusion that neurobehavioral effects can be caused by the relatively low lead exposures in Denmark may not be surprising, as current exposures to this toxic metal greatly exceed the prepollution levels to which the human body originally adapted.

Low-Level Lead Exposure and Children's Cognitive Function in the Preschool Years

In a cohort of 170 middle and upper-middle class children participating in a prospective study of child development and low-level lead exposure, higher blood lead levels at age 24 months were associated with lower scores at age 57 months on the McCarthy Scales of Children's Abilities. The mean blood lead level at age 24 months was 6.8 micrograms/dL (SD = 6.3; 75th, 90th, and 99th percentiles: 8.8, 13.7, 23.6, respectively) and for all but 1 child was less than 25 micrograms/dL, the current definition of an "elevated" level. After adjustment for confounding, scores on the General Cognitive Index decreased approximately 3 points (SE = 1.4) for each natural log unit increase in 24-month blood lead level. The inverse association between lead level and performance was especially prominent for visual-spatial and visual-motor integration skills. Higher prenatal exposures were not associated with lower scores at 57 months except in the subgroup of children with "high" concurrent blood lead levels (ie, greater than or equal to 10 micrograms/dL). The concentration of lead in the dentine of shed deciduous teeth was not significantly associated with children's performance after adjustment for confounding.

Learning Disabilities in Children: Significance of Low‐Level Lead‐Exposure and Confounding Factors

The hypothesis that low-level lead absorption is a risk factor for learning disabilities in school children was examined in the municipality of Aarhus, Denmark. During 1982-1983, a total of 1,302 children in the first grade (54% of the eligible population) delivered shed deciduous teeth. The lead concentration in the circumpulpal dentin was used as an indicator of the cumulated lead absorption, and 200 cases (high-lead) and controls (low-lead) were selected, and matched for socioeconomic group and gender. The parents were interviewed regarding the child's development and past medical history. Possible confounders were identified and controlled for in a logistic multivariate model. The influence of lead absorption became statistically significant only after exclusion of the children with proven medical risk factors, thereby the adjusted odds ratio in the weighted analysis was changed from 2.2 to 4.3. Thus, in a Scandinavian low-level lead-polluted area, lead absorption appears to be a risk factor for learning disabilities.

Factors influencing lead concentrations in shed deciduous teeth

Data collected for the Edinburgh Lead Study have been used to investigate lead concentrations in children's naturally shed deciduous teeth. A within-child multiple-regression analysis has shown that the upper jaw has a higher concentration of lead than the lower, and that there is a gradient of decreasing concentration from the front to the back of the mouth. Even after the effects of jaw and tooth type have been allowed for, the concentration is still found to be negatively correlated with the weight of the tooth and with the age at which the tooth was shed. No statistically significant effects could be attributed to caries, fillings, or the incomplete resorption of roots. A single-valued index of tooth lead has been derived for each child, taking into account the fact that children gave different types of teeth.

Exposure to lead and cadmium of children living in different areas of north-west Germany: results of biological monitoring studies 1982-1986.

Between 1982 and 1986 several surveys were carried out to determine the levels of lead and cadmium in blood, urine, and shed deciduous teeth (incisors only) of children living in rural, suburban, urban, and industrial areas of North-West Germany. Blood lead (PbB) and blood cadmium (CdB) were measured in about 4000 children. In rural, suburban and urban areas the median PbB levels vary between 5.5 and 7 micrograms/dl, with 98th percentiles varying between 10 and 13 micrograms/dl. The median CdB levels are between 0.1 and 0.2 microgram/dl, with 95th percentiles between 0.3 and 0.4 microgram/l. Children from urban areas have significantly higher PbB levels than children from rural and suburban areas. Regarding CdB no differences could be detected. Children living in areas around lead and zinc smelters, particularly those living very close to the smelters, have substantially increased PbB and CdB levels. Children from lead worker families also have substantially increased PbB and CdB levels. The lead levels in shed milk teeth (PbT) were determined in about 3000 children. In rural, suburban and urban areas the median PbT levels are between 2 and 3 micrograms/g, with 95th percentiles between 4 and 7 micrograms/g. Children from urban areas have significantly higher PbT levels than children from rural and suburban areas. The highest PbT levels (on a group basis) are in children from nonferrous smelter areas. The median levels of lead in urine (PbU) are between 6 and 10 micrograms/g creatinine, with 95th percentiles between 20 and 30 micrograms/g creatinine. Children from polluted areas have higher PbU levels than children from less polluted areas. The median levels of cadmium in urine (CdU) are in the order of 0.1 microgram/g creatinine, with 95th percentiles being in the range of 0.5 and 1.0 microgram/g creatinine. Girls have higher CdU levels than boys. There are no differences between groups of children from different areas. Children from lead worker families have higher PbU and CdU levels than otherwise comparable children. The results of the present studies indicate a further decrease of PbB in children from North-West Germany since the CEC blood lead campaigns carried out in 1979 and 1981. The decrease of lead exposure also seems to be reflected by a decrease of tooth lead levels.

Subclinical lead exposure in philadelphia schoolchildren. Identification by dentine lead analysis.

Abstract Dentine lead levels were measured from shed deciduous teeth of 761 Philadelphia schoolchildren with no prior history of lead poisoning and residing in two school districts, one considered high risk for lead exposure, and one considered low risk. Black children in public schools from areas of deteriorated housing had marked elevations of dentine lead (mean of 198 μg per gram, in 174 children), with 20 per cent of the children having levels in the range associated with toxicity. White children from newer housing had the lowest levels (mean of 41.7μg per gram, 304 children), but a group of white children from intact housing living near and attending school adjacent to a major lead processor also had elevations of dentine lead (mean of 136 μg per gram, 71 determinations). Lead exposure as defined by dentine lead levels is more serious and widespread than previously acknowledged, and extends to groups other than those traditionally accepted as at risk. (N Engl J Med 290:245–248, 1974).

Prediction models for 90Sr in shed deciduous teeth and infant bone.

Shed deciduous teeth were collected in 1966-69 in Denmark, the Faroes and Greenland from children born in the period 1953-63. 235 samples of crowns were analysed for 90Sr. The 90Sr levels in deciduous tooth crowns were related to the fall-out rate and the accumulated fall-out. The tooth levels in children born in 1950-62 could be described with the same equation as the 90Sr bone levels in 1-yr-old infants born in 1962-68. The prediction models for 90Sr in teeth and bones showed that for given amount of fall-out the Faroese levels became nearly twice as high as the Danish. The maximum teeth and bone levels were found in children born in 1963, where the Faroese level was estimated from the prediction model to be 24 pCi 90Sr/g Ca.

Strontium-90 in shed deciduous teeth collected in Denmark, the Faroes and Greenland from children born in 1950-1958.

Strontium-90 in shed deciduous teeth collected in Denmark, the Faroes and Greenland from children born in 1950-1958.