Use of Dental Defects Associated with Low-Dose di(2-Ethylhexyl)Phthalate as an Early Marker of Exposure to Environmental Toxicants.

backgroundMarkers of exposure to environmental toxicants are urgently needed. Tooth enamel, with its unique properties, is able to record certain environmental conditions during its formation. Enamel formation and quality are dependent on hormonal regulation and environmental conditions, including exposure to endocrine disrupting chemicals (EDCs). Among EDCs, phthalates such as di-(2-ethylhexyl) phthalate (DEHP) raise concerns about their contribution to various pathologies, including those of mineralized tissues.

objectivesThe effects of exposure to low-doses of DEHP on the continually growing incisors were analyzed in mouse males and females.

methodsAdult male and female C57BL/6J mice were exposed daily to 0.5, 5, and

resultsClinical macroscopic observations of incisors showed various dose-dependent dental lesions such as opacities, scratches, and enamel breakdown in 30.5% of males (10 of 34 total incisors across three independent experiments), and 15.6% of females (7 of 46 incisors) at the highest dose, among which 18.1% (6 of 34 total incisors across three independent experiments) and 8.9% (4 of 46 incisors), respectively, had broken incisors. SEM showed an altered enamel surface and ultrastructure in DEHP-exposed male mice. Further characterization of the enamel defects in males by DISCUSSION: We conclude that DEHP disrupted enamel development in mice by directly acting on dental cells with higher prevalence and severity in males than in females. The time window of DEHP effects on mouse tooth development led to typical alterations of structural, biochemical, and mechanical properties of enamel comparable to other EDCs, such as bisphenol A. The future characterization of dental defects in humans and animals due to environmental toxicants might be helpful in proposing them as early markers of exposure to such molecules. https://doi.org/10.1289/EHP10208.