Tooth Fairy Study- The South Texas Oral Health Network Collaboration.

PURPOSE: This study's purpose was to examine the processes and the potential for dental practitioners to address environmental health exposure risks to their patients through dental practice-based research participation. To explore this, the South Texas Oral Health Network (STOHN) initiated a collaboration with The Tooth Fairy National Study investigating toxicants stored in deciduous teeth as a potential neurodevelopmental risk factor. BACKGROUND: Neurodevelopmental disorders (ND), like Autism Spectrum Disorder (ASD), affect 1 in 68 live births. Evidence suggests that environmental chemicals may play a role in ASD risk and/or etiology by acting independently or through interactions with genetic vulnerabilities. Provider awareness of environmental exposure risk during pregnancy and early childhood in South Texas is low. Therefore, it is important to increase provider knowledge and awareness to enable greater communication with patients. STOHN serves as a conduit reaching large numbers of patients. This study also engaged practitioners in an ongoing national study with minimal impact on their practice. METHODS: The goal was to enroll twenty parents with children via ten dental practitioners. STOHN pediatric and general practitioners were recruited for the study. Practitioners were contacted by phone and in person. Upon completion of Human Subject Protection training, each practitioner participated in a study training taught by a public health educator in the department of Family and Community Medicine at University of Texas Health Science Center in San Antonio (UTHSCSA). Training topics included NDs, environmental health exposures, patient engagement, survey administration, and how to collect donated teeth. This collaboration allowed STOHN to gather control teeth as well as demographic and health information for the Tooth Fairy Study repository for future analyses. Participants received a thank you card from the Tooth Fairy and participating providers were highlighted in the monthly STOHN newsletter. EVALUATION RESULTS: Evaluation was threefold: Practitioner enrollment and retention; practitioner confidence in educating their patients about potential environmental risk exposures and completed surveys with donated teeth. CONCLUSION: The interdisciplinary collaboration between dental practitioners and medical researchers through STOHN provided an opportunity to increase practitioner knowledge and awareness of a novel health concern, while also raising their confidence and willingness to educate their patients about potential environmental exposure risks. UTHSCSA IRB Protocol # HSC20170132E.

An Exploratory Investigation of Organic Chemicals Detected in Baby Teeth: Differences in Children with and without Autism.

Autism spectrum disorder (ASD) is a behaviorally defined neurodevelopmental disorder characterized by deficits in language, communication, and social function with an estimated prevalence rate of between 1 in 30 and 44 U.S. births. Gene/environment (G × E) interactions are widely regarded as the most probable explanation for idiopathic ASD, especially because some genes are selectively targeted by various environmental xenobiotics. Because deciduous teeth are a likely biomarker of in utero exposure, the present study investigated if the quantity of chemicals found in deciduous teeth differs between children with and without ASD. Twenty-two deciduous teeth from children with ASD and 20 teeth from typically developed children were prepared and analyzed using THE Two-Dimensional Gas Chromatography Time-of-Flight Mass Spectrometer (GC × GC-TOF MS) with ChromaTOF version 23H2 software and Agilent 7890 gas chromatograph. The autism sample had significantly more chemicals in their teeth than the typical developing sample (99.4 vs. 80.7, respectively) (p < 0.0001). The majority of chemicals were identified as phthalates, plasticizers, pesticides, preservatives, or intermediary solvents used in the production of fragranced personal care or cleaning products or flavoring agents in foods. The known toxic analytes reported in this study are likely biomarkers of developmental exposure. Why there were greater concentrations of toxic chemicals in the teeth that came from children with ASD is unclear. A further understanding of the cavalcade of multiple biological system interactions (Interactome) could help with future efforts to reduce risks. Notwithstanding, the avoidance of pesticides, plastics, and scented personal care products may be warranted under the precautionary principle rule.

Daily Early-Life Exposures to Diet Soda and Aspartame Are Associated with Autism in Males: A Case-Control Study.

Since its introduction, aspartame-the leading sweetener in U.S. diet sodas (DS)-has been reported to cause neurological problems in some users. In prospective studies, the offspring of mothers who consumed diet sodas/beverages (DSB) daily during pregnancy experienced increased health problems. We hypothesized that gestational/early-life exposure to ≥1 DS/day (DSearly) or equivalent aspartame (ASPearly: ≥177 mg/day) increases autism risk. The case-control Autism Tooth Fairy Study obtained retrospective dietary recalls for DSB and aspartame consumption during pregnancy/breastfeeding from the mothers of 235 offspring with autism spectrum disorder (ASD: cases) and 121 neurotypically developing offspring (controls). The exposure odds ratios (ORs) for DSearly and ASPearly were computed for autism, ASD, and the non-regressive conditions of each. Among males, the DSearly odds were tripled for autism (OR = 3.1; 95% CI: 1.02, 9.7) and non-regressive autism (OR = 3.5; 95% CI: 1.1, 11.1); the ASPearly odds were even higher: OR = 3.4 (95% CI: 1.1, 10.4) and 3.7 (95% CI: 1.2, 11.8), respectively (p < 0.05 for each). The ORs for non-regressive ASD in males were almost tripled but were not statistically significant: DSearly OR = 2.7 (95% CI: 0.9, 8.4); ASPearly OR = 2.9 (95% CI: 0.9, 8.8). No statistically significant associations were found in females. Our findings contribute to the growing literature raising concerns about potential offspring harm from maternal DSB/aspartame intake in pregnancy.

Early life metal exposure dysregulates cellular bioenergetics in children with regressive autism spectrum disorder.

Neurodevelopmental regression (NDR) is a subtype of autism spectrum disorder (ASD) that manifests as loss of previously acquired developmental milestones. Early life dysregulation of nutritional metals and/or exposure to toxic metals have been associated with ASD, but the underlying biological mechanisms by which metals influence neurodevelopment remain unclear. We hypothesize that metals influences neurodevelopment through dysregulation of bioenergetics. Prenatal and early postnatal metal exposures were measured using validated tooth-matrix biomarkers in 27 ASD cases (13 with NDR) and 7 typically-developing (TD) controls. Mitochondrial respiration and glycolysis were measured in peripheral blood mononuclear cells using the Seahorse XF96. Children with ASD demonstrated lower prenatal and postnatal Copper (Cu) and prenatal Nickel concentrations and Copper-to-Zinc (Cu/Zn) ratio as compared with TD children. Children with ASD and NDR showed greater metal-related disruption of cellular bioenergetics than children with ASD without NDR. For children with ASD and NDR mitochondrial respiration decreased as prenatal Manganese concentration increased and increased as prenatal Zinc concentration increased; glycolysis decreased with increased exposure to prenatal Manganese and Lead and postnatal Manganese. For children with ASD without a history of NDR, glycolysis increased with increased postnatal exposure to Tin. Language and communication scores in children with ASD were positively related to prenatal Cu exposure and Cu/Zn ratio. This study suggests that prenatal nutritional metals may be important for neurodevelopment in children with ASD, and that exposure to toxic metals and differences in nutritional metal exposures is associated with dysregulation of cellular bioenergetics, particularly in the NDR subtype of ASD.

Dynamical features in fetal and postnatal zinc-copper metabolic cycles predict the emergence of autism spectrum disorder.

Metals are critical to neurodevelopment, and dysregulation in early life has been documented in autism spectrum disorder (ASD). However, underlying mechanisms and biochemical assays to distinguish ASD cases from controls remain elusive. In a nationwide study of twins in Sweden, we tested whether zinc-copper cycles, which regulate metal metabolism, are disrupted in ASD. Using novel tooth-matrix biomarkers that provide direct measures of fetal elemental uptake, we developed a predictive model to distinguish participants who would be diagnosed with ASD in childhood from those who did not develop the disorder. We replicated our findings in three independent studies in the United States and the UK. We show that three quantifiable characteristics of fetal and postnatal zinc-copper rhythmicity are altered in ASD: the average duration of zinc-copper cycles, regularity with which the cycles recur, and the number of complex features within a cycle. In all independent study sets and in the pooled analysis, zinc-copper rhythmicity was disrupted in ASD cases. In contrast to controls, in ASD cases, the cycle duration was shorter (F = 52.25, P < 0.001), regularity was reduced (F = 47.99, P < 0.001), and complexity diminished (F = 57.30, P < 0.001). With two distinct classification models that used metal rhythmicity data, we achieved 90% accuracy in classifying cases and controls, with sensitivity to ASD diagnosis ranging from 85 to 100% and specificity ranging from 90 to 100%. These findings suggest that altered zinc-copper rhythmicity precedes the emergence of ASD, and quantitative biochemical measures of metal rhythmicity distinguish ASD cases from controls.

Organic Compounds Detected in Deciduous Teeth: A Replication Study from Children with Autism in Two Samples.

Biological samples are an important part of investigating toxic exposures and disease outcomes. However, blood, urine, saliva, or hair can only reflect relatively recent exposures. Alternatively, deciduous teeth have served as a biomarker of early developmental exposure to heavy metals, but little has been done to assess organic toxic exposures such as pesticides, plastics, or medications. The purpose of our study was to determine if organic chemicals previously detected in a sample of typically developing children could be detected in teeth from a sample of children with autism. Eighty-three deciduous teeth from children with autism spectrum disorders (ASD) were chosen from our tooth repository. Organic compounds were assessed using liquid chromatography tandem mass spectrometry and gas chromatography methods. Consistent with a prior report from Camann et al., (2013), we have demonstrated that specific semivolatile organic chemicals relevant to autism etiology can be detected in deciduous teeth. This report provides evidence that teeth can be useful biomarkers of early life exposure for use in epidemiologic case-control studies seeking to identify differential unbiased exposures during development between those with and without specific disorders such as autism.

Acetaminophen, pesticide, and diethylhexyl phthalate metabolites, anandamide, and fatty acids in deciduous molars: potential biomarkers of perinatal exposure.

The developing fetus is particularly vulnerable to adverse effects from pharmaceutical and exogenous chemical exposure. Deciduous teeth primarily form over specific periods from the second trimester in utero through the months after birth. We hypothesized that organic chemicals or their metabolites circulating in the bloodstream may sorb into forming dental tissues and remain stored in the tooth thereafter. Our aims were to devise analytical and preparation methods for potentially toxic or beneficial organic chemicals or metabolites in deciduous teeth and to estimate their detection frequencies. The analgesic acetaminophen was stored at greater concentration in a child's second molar than a first molar, consistent with intake, suggesting that acetaminophen concentration in molars may be a biomarker of acetaminophen exposure during molar formation. Chemicals detected by liquid chromatography/tandem mass spectrometry in molars of 21 typically developing children include the endocannabinoid anandamide (86% of children), acetaminophen (43%), and specific metabolites mono-2-ethylhexyl phthalate (MEHP, of plasticizer di-2-ethylhexyl phthalate, 29%), 3,5,6-trichloro-2-pyridinol (TCPy, of organophosphate (OP) insecticide chlorpyrifos, 10%), and 2-isopropyl-6-methyl-4-pyrimidinol (IMPy, of OP insecticide diazinon, 10%). None of these chemicals has previously been detected in human teeth. Molars from the two oldest subjects contained the largest concentrations of MEHP, TCPy, and IMPy. Potentially protective fatty acids detected by gas chromatography/mass spectrometry after derivatization include docosahexaenoic (19%), arachidonic (100%), and linoleic (100%). Validation studies are necessary to verify that each detected chemical in molars provides a biomarker of perinatal exposure.