Environmental tobacco smoke exposure and non-syndromic orofacial cleft: Systematic review and meta-analysis

Association between exposure to environmental pollutants and increased oral health risks, a comprehensive review

The burden of disease and death attributable to environmental pollution is a growing public health challenge worldwide, particularly in developing countries. While the adverse effects of environmental pollution on oral health have garnered increasing attention, a comprehensive and systematic assessment remains lacking. This article delves into the intricate relationship between environmental pollution and oral health, highlighting significant impacts on various aspects such as dental caries, periodontal diseases, oral facial clefts, cancer, as well as other oral diseases. Our results suggested that secondhand smoke, particulate matters (PM) and heavy metals are the most important risk factors affecting oral health. Additional contributors, such as radiation pollutants, electronic cigarette, phthalates, gaseous air pollutants, pesticides, solvents, wood dust, formaldehyde and excessive fluoride were investigated, though evidence for their impacts remains limited and often inconclusive. The review also explores potential mechanisms underlying these impacts, including microorganism, inflammation, oxidative stress, genetic influences, and toxicant exposures from heavy metals and other pollutants. For instance, PM2.5 may contribute to dental caries by disrupting oral pH balance and absorbing heavy metals such as lead and cadmium which have been considered as caries promoting elements. It is also associated with adverse inflammatory responses and tissue damage in periodontal tissues by causing oxidative stress, potentially leading to periodontitis. Drawing on current evidence, it provides a comprehensive analysis of these associations, offering critical insights to guide the development of preventive strategies and public health interventions. The findings highlight the pressing need for future research to validate the causal links between environmental pollution and oral diseases and to unravel the underlying biological mechanisms. Ultimately, greater attention must be directed toward addressing the relationship between environmental pollution and oral diseases, with a focus on pollution control and the reduction of preventable environmental risks to safeguard oral health on a broader scale.

COVID-19 vaccine and non-syndromic orofacial clefts in five arab countries. A case-control study

OBJECTIVES

Risk factors for non-syndromic orofacial cleft (NSOFCs) include genetic profile and environmental exposure to medication and illnesses during pregnancy. We assessed the association between the COVID-19 vaccination and the incidence of NSOFC across five Middle Eastern countries.

MATERIALS AND METHODS

This multi-country, hospital-based, case-control study included infants with NSOFCs whose first 3 intrauterine months coincided with the time when pregnant women were allowed to receive COVID-19 vaccination in the countries participating in the study. Newborns with NSOFCs were examined for cleft type and their parents were interviewed for maternal exposures and COVID-19 vaccination. Controls were newborns matched to cases in gender and setting.

RESULTS

The study recruited 977 (348 children with NSOFCs and 629 controls). Maternal use of nicotine (Adjusted Odds Ratio (AOR): 2.437; P = 0.044) and family history of NSOFC (AOR: 11.059; P < 0.001) increased significantly the AOR of having a child with NSOFC. On the other hand, COVID-19 vaccine administration to pregnant mothers have significantly decreased the AOR of having a child with NSOFC (AOR: 0.337; P = 0.006).

CONCLUSION

This study suggests that COVID-19 vaccination is not related to NSOFC and might protect against having a child affected with such a congenital anomaly.

CLINICAL RELEVANCE

The finding of this study is important for healthcare providers for considering COVID-19 vaccination for pregnant woman. Clear communication and education about the potential risks and benefits would be crucial for informed decision-making. The study's results would directly impact pregnant individuals, as they would need accurate information to make informed decisions about their health and the health of their infants.

Integrated mRNA- and miRNA-sequencing analyses unveil the underlying mechanism of tobacco pollutant-induced developmental toxicity in zebrafish embryos

Tobacco pollutants are prevalent in the environment, leading to inadvertent exposure of pregnant females. Studies of these pollutants' toxic effects on embryonic development have not fully elucidated the potential underlying mechanisms. Therefore, in this study, we aimed to investigate the developmental toxicity induced by cigarette smoke extract (CSE) at concentrations of 0.25, 1, and 2.5% using a zebrafish embryo toxicity test and integrated transcriptomic analysis of microRNA (miRNA) and messenger RNA (mRNA). The findings revealed that CSE caused developmental toxicity, including increased mortality and decreased incubation rate, in a dose-dependent manner. Moreover, CSE induced malformations and apoptosis, specifically in the head and heart of zebrafish larvae. We used mRNA and miRNA sequencing analyses to compare changes in the expression of genes and miRNAs in zebrafish larvae. The bioinformatics analysis indicates that the mechanism underlying CSE-induced developmental toxicity was associated with compromised genetic material damage repair, deregulated apoptosis, and disturbed lipid metabolism. The enrichment analysis and RT-qPCR show that the ctsba gene plays a crucial function in embryo developmental apoptosis, and the fads2 gene mainly regulates lipid metabolic toxicity. The results of this study improve the understanding of CSE-induced developmental toxicity in zebrafish embryos and contribute insights into the formulation of novel preventive strategies against tobacco pollutants during early embryonic development.

US air pollution is associated with increased incidence of non-syndromic cleft lip/palate

Maternal cigarette use is associated with the fetal development of orofacial clefts. Air pollution should be investigated for similar causation. We hypothesize that the incidence of non-syndromic cleft lip with or without palate (NSCLP) and non-syndromic cleft palate (NSCP) would be positively correlated with air pollution concentration.

METHODS

The incidence of NSCLP and NSCP per 1000 live births from 2016 to 2020 was extracted from the Centers for Disease Control and Prevention Vital Statistics Database and merged with national reports on air pollution using the Environmental Protection Agency Air Quality Systems annual data. The most commonly reported pollutants were analyzed including benzene, sulfur dioxide (SO2), particulate matter (PM) 2.5, PM 10, ozone (O3), and carbon monoxide (CO). Multivariable negative binomial and Poisson log-linear regression models evaluated the incidence of NSCLP and NSCP as a function of the pollutants, adjusting for race. All p-values are reported with Bonferroni correction.

RESULTS

The median NSCLP incidence was 0.22/1000 births, and isolated NSCP incidence was 0.18/1000 births. For NSCLP, SO2 had a coefficient estimate (CE) of 0.60 (95% CI [0.23, 0.98], p < 0.007) and PM 2.5 had a CE of 0.20 (95% CI [0.10, 0.31], p < 0.005). Among isolated NSCP, no pollutants were found to be significantly associated.

CONCLUSION

SO2 and PM 2.5 were significantly correlated with increased incidence of NSCLP. The American people and perinatal practitioners should be aware of the connection to allow for risk reduction and in utero screening.