Researchers at the Icahn School of Medicine at Mount Sinai partnered with Sweden's Karolinska Institutet to study the baby teeth of patients with autism spectrum disorder (ASD).

Their study, "Fetal and postnatal metal dysregulation in autism," was published in Nature Communications in April. It detailed that biomarkers in the layers of the ASD patients' teeth revealed they were exposed to higher concentrations of lead and other neurotoxins in utero and within the first months of life.

Baby teeth from identical twins (at least one of whom was diagnosed with ASD), as well as identical twins without ASD, revealed the timeline of microchemical composition exposure throughout the earliest years of the children's lives. Dentine, the material that makes up inner tooth layers, retains an imprint of the microchemicals absorbed by the body from the earliest development of the tooth.

Teeth develop beginning in the fetal stages and the first few years after birth. With each week, a new layer of dentine is formed. Each layer of dentine contains traces of the minerals and micronutrients the baby is exposed to, whether through the mother's nutrients or in their living environment post-birth.

Tooth-matrix biomarkers in the teeth of ASD patients showed higher levels of lead — a chemical that is widely known for being a neurotoxin. Lead has been tied to many detrimental effects on the brain, such as lower intelligence and overall lower cognitive function.

High levels of lead found in dentine layers developed around three months post-birth were more likely to predict severe cases of autism.

Conversely, low levels of manganese were consistent in ASD patients concerned with teeth of the control group. Researchers noted this dip in manganese level was prevalent in the first trimester and 15 weeks post-birth. They also found the difference was as much as 2.5 times lower than that of the twin without ASD.

Furthermore, biomarkers with low levels of zinc were also discovered. The greatest deficiencies (as much as 28 percent lower than average) were found in dentine from the same time periods as the lowest levels of manganese.

Medical professionals, from doctors to dentists, need to be vigilant about recommending proper neonatal vitamins to pregnant patients. Many women are unaware of the impact their nutrition has on the baby; professionals can help remedy this by providing information and referring them to trusted educational sources.

Additionally, while homebuilders today are cognizant of materials with lead, many older homes still contain toxic amounts in the materials and pipes. Recommend patients keep an eye out for possible sources of lead and other neurotoxins to prevent unnecessary exposure.