Environmental toxins and molar incisor hypo-mineralisation among children: A cohort study

Abstract

Abstract Environmental toxins are known to have many impacts on growth and development in humans, starting in utero. Alterations in amelogenesis, caused by chemical and physical trauma that occur during the antenatal, perinatal and postnatal time periods, can result in developmental defects in deciduous and permanent tooth enamel. These defects can be clinically visible and result in a variety of morphological and functional problems in the dentition. Since enamel does not remodel after formation, it may be used as a permanent record of insults during organ development. A cohort of children from the Utah Children’s Project (N = 356) that had full phenotyping, comprehensive medical and family histories and available biospecimens were given extraoral and intraoral examinations. Standardized intraoral photographs were taken of the teeth and viewed by standardised examiners and the dental observations were recorded on a range of findings, including: tooth morphology, caries, restorations, colorations, attrition, erosion, fractures and hypomineralization. Perinatal maternal urine samples were assessed for the concentration of fluoride, phenols and phthalates, including bisphenol A (BPA). Pairwise statistical analyses were done to correlate the dental findings with one another and the presence of environment chemicals found in the urine samples. Hypomineralization was the most common finding and was strongly correlated with tooth attrition. The hypomineralization observed was consistent with molar incisor hypomineralization (MIH) described in other human populations. In animal studies, BPA concentration has been correlated with increased levels of MIH. No significant correlations were seen between dental findings and the presence of environmental chemicals in prenatal urine, but the number of samples available for the assessment was limited (n = 35).