Prevalence Of Orofacial Clefts Research Articles

The prevalence of orofacial clefts in Qatar : a cross-sectional nationwide study

BackgroundCleft lip and palate are congenital craniofacial anomalies that significantly impact individuals and their families, both medically and psychosocially. The Qatari population has unique characteristics that are suggestive of a high prevalence of congenital anomalies: high consanguinity rate, large family size, advanced paternal age and high prevalence of certain genetic disorders. The lack of existing data concerning the epidemiology of cleft lip and/or palate in Qatar warrants a descriptive study addressing this topic.MethodsA retrospective nationwide hospital-based cross-sectional study conducted to determine the prevalence of orofacial clefts in Qatar from 2016 to 2021. Data were extracted from the corporation’s Cerner database and electronic health records. Information concerning the cleft’s characteristics, type, affected side, patient’s gender, presence of associated syndromes, nationality, and maternal age were collected.ResultsOut of the 147,727 live births, 148 had an orofacial cleft. The prevalence of cleft lip and/or palate was determined to be 1 per 1000 livebirths (95% CI: 0.85, 1.18). The prevalence of cleft lip was 0.18 (95% CI: 0.12, 0.27), cleft palate 0.39 (95% CI: 0.30, 0.51), and cleft lip and palate 0.43 (95% CI: 0.33, 0.55). Qataris had a prevalence of CL 0.25, CP 0.40, and CLP 0.56, compared to 0.16, 0.39, 0.39 for non-Qataris (p-value 0.186). Unilateral clefts predominated over bilateral (74.4% and 25.6%, respectively). Among the unilateral cases, 70.2% occurred on the left side. Most cases were isolated clefts, with only 10.2% having associated syndromes.ConclusionsThe prevalence of orofacial clefts in Qatar is consistent with the globally reported prevalence. Most cases were unilateral and on the left side. Associated syndromes were infrequent and more common with cleft palate alone. Intriguing patterns were revealed between Qatari nationals and non-Qatari residents, with specific subtypes of orofacial clefts showing higher prevalence among nationals.

Orofacial clefts in Costa Rica, 1996-2021: Analysis of surveillance data.

Orofacial clefts (OFCs) are among the most common birth defects (BD). In 2008, a series of improvements began in the Costa Rican Birth Defect Register Center (CREC). We aim to explore trends between 1996 and 2021. A trend analysis of OFCs from 1996 to 2021 and a descriptive analysis of OFCs from 2010 to 2021 were performed based on data from the CREC, the national BD surveillance system. Prevalence at birth was calculated according to the type: cleft palate (CP), cleft lip with or without CP (CL ± P), and presentation (isolated, multiple non-syndromic, or syndromes). We used joinpoint regression to identify if a significant change in trend occurred; the average annual percent change (AAPC) was determined. Marginal means and prevalence ratios by subperiod (1996-2009 as referent and 2010-2021) were estimated using Poisson regression and compared using Wald's chi-square tests (α ≤.05). We found a significant AAPC for OFCs prevalence of +1.4: +0.6 for isolated, +2.9 for multiple non-syndromic, and +7.7 for syndromes (p < .05). When comparing the OFC's prevalence of the subperiod 2010-2021 (11.86 per 10,000) with 1996-2009 (9.36 per 10,000) the prevalence ratio was 1.3 (p < .01): 1.1 (p < .05) for isolated, 1.6 (p < .01) for multiple non-syndromic, and 3.3 (p < .01) for syndromes. The prevalence of OFCs from 2010 to 2021 was 9.1 for CL ± P and 2.8 for CP. Seventy-one percent of the OFCs were isolated, 22% multiple non-syndromic, and 7% syndromes. The trend in OFCs' prevalence is toward increasing, mainly due to improvements in the surveillance system.

Prevalence of Orofacial Clefts: A Retrospective Cross-sectional Analysis of Gynecology and Obstetrics Hospital Records in the City of Sulaimani, Kurdistan Region of Iraq

Prevalence of Orofacial Clefts: A Retrospective Cross-sectional Analysis of Gynecology and Obstetrics Hospital Records in the City of Sulaimani, Kurdistan Region of Iraq

Prevalence and Patterns of Orofacial Clefts among Children from Different Regions of Saudi Arabia: A Systematic Review.

To report on the prevalence and patterns of orofacial clefts (OFC) among Saudi Arabian children by analyzing the results of the studies that have been reported in the literature. A data search was carried out for the articles that had reported on the prevalence of OFC among the Saudi Arabian population in databases like Web of Science, PubMed, Google Scholar, Scopus, and Saudi Digital Library. Articles that were published over the last 15 years were included in this study, following which 13 studies were assessed for qualitative data. Newcastle-Ottawa Quality Assessment Scales for cross-sectional studies were used for analyzing the methodological quality of these studies. The prevalence of OFC was within the range of 0.65-1.9/1,000 live births. The highest was witnessed in the Medina region. Parent's consanguinity was the most common risk factor in OFC cases in the included studies. OFC was found to be higher among the male population in comparison with the female. The prevalence of OFC in Saudi Arabian children follows the global patterns of OFC. Isolated cleft lip (CL) and cleft palate (CP) are the most common forms of OFC. The prevalence of orofacial anomalies was reported more among children born to parents who had consanguineous marriages. Considering the higher rate of consanguinity among this population, there is an urgent need of developing educational and counseling programs to address the genetic consequences. Albalawi F Alsaeed S, Alalola B, et al. Prevalence and Patterns of Orofacial Clefts among Children from Different Regions of Saudi Arabia: A Systematic Review. Int J Clin Pediatr Dent 2023;16(1):124-130.

Seasonal, Geographic, and Ethnic Influence on the Prevalence of Orofacial Clefts in Kuwait: A Nationwide Study.

Accurate nationwide epidemiological evidence is vital to study the seasonal, geographic, and ethnic influence on the trends of orofacial cleft prevalence in Kuwait. Data obtained from the National Center for Health Information and Ministry of Health Hospital digital records were reviewed retrospectively to identify patients with orofacial clefts (OFC) using the ICD-10 diagnostic codes. The Jonckheere-Terpstra test was used to assess the trend of birth prevalence across the different years. The associations of types of OFC with ethnic and geographic influences were tested with chi-square or Fisher's exact tests, while the strength of that association was tested with multi-nominal logistic regression. Birth prevalence in Kuwait ranged from 0.75-2.55 per 1000 live births (0.73- 2.73 among Kuwaitis, 0.60-3.27 among non-Kuwaitis), with no statistically significant change observed during the past 28 years. The risk of unilateral cleft lip and palate was eight times higher during summer compared to Autumn, while the risk of cleft lip and palate remained lower during winter. Jahra (OR-7.76, CI- 1.51-39.80), Farwaneya (OR-6.65, CI- 1.34-33.06), and Hawalli (OR-6.72, CI- 1.26-35.98) governorates had higher odds of bilateral cleft lip when compared to Mubarak Alkabeer. The study outcome is an indicator to improve patient care and customize healthcare infrastructure in the Ministry of Health. It also provides insight to develop projections of future needs. Future studies should focus on understanding the factors that might be a potential contributor to the seasonal change observed in the prevalence of OFC.

The Prevalence of Cleft Lip and Palate and Their Effect on Growth and Development: A Narrative Review

Cleft lip and/or cleft palate (CL±P) in addition to the cleft palate (CP) are a category of anomalies known as orofacial clefts (OC). These anomalies are accompanied by several aesthetic and functional problems. Information on the prevalence of OC showed different values between studies worldwide. In addition, the presence of cleft lip and/or cleft palate is determined by several changes during the embryonic stage. Besides, cleft repair may lead to a significant impact on the overall aesthetic and function and could negatively affect maxillary growth on certain occasions. Therefore, having the background and knowledge on this phenomenon is essential in designing the overall treatment and obtaining outcomes that are as close to normal as possible. This article reviews the maxillary development, occurrence of cleft lip and/or palate and their prevalence, facial growth in the presence of clefts, effect of cleft repair, an overview of alveolar cleft treatment, as well as the essential information related the prevention of cleft lip and palate.

Orofacial Clefts in High Prevalence Area of Birth Defects - Five Counties, Shanxi Province, China, 2000-2020.

What is already known on this topic?The prevalence of structural birth defects, especially neural tube defects, decreased after national folic acid (FA) supplementation initiation.What is added by this report?The prevalence of orofacial clefts (OFCs) in five counties of Shanxi Province in northern China, including most subtypes except cleft palate, showed a downward trend in the past two decades. In this study, pre-perinatal prevalence increased due to earlier detection.What are the implications for public health practice?Periconceptional supplementation with FA may contribute to the decline in OFCs prevalence, while the effect on the OFCs subtype needs further investigation. Continuing to advocate for earlier supplementation (3 months before conception) and increased supplementation frequency (daily consumption) could promote further reduction in the prevalence of OFCs. Specific surveillance of this effect in the era of universal three-child policy is warranted.

Surgical Repair of Orofacial Clefts in North Kivu Province of Eastern Democratic Republic of Congo (DRC).

There is a high prevalence of orofacial clefts in low- and middle-income countries with significant unmet need, despite having 50% of the population younger than 18 years in countries such as the Democratic Republic of Congo (DRC). The purpose of this article is to report on the experience of general surgeons with orofacial clefts at a single institution. This is a retrospective study of patients treated for cleft lip/palate in the province of North Kivu, DRC between 2008 and 2017. A total of 1112 procedures (122/year) were performed. All procedures were performed by general surgeons following training by an international nongovernmental aid organization. A total of 59.2% of patients were male and the median age was 3.4 years (interquartile range: 0.7-13 years). Average distance from surgical center to patient location was 242.6 km (range: 2-1375 km) with outreach performed for distances >200 kms. A majority (82.1%) of patients received general anesthesia (GA) with significant differences in use of GA, age, weight, and length of stay by major orofacial cleft category. Of the 1112 patients, 86.1% were reported to have cleft lip alone, 10.5% had cleft lip and palate, and 3.4% cleft palate alone. Despite this, only 5.3% of patients underwent surgical repair of cleft palate. Multiple factors including malnutrition, risk of bleeding, procedural complexity, and cosmetic results may contribute to the distribution of procedures performed where most cleft palates are not treated. Based on previously published estimates, unmet needs and social burden of cleft lip and palate are high in the DRC.

Social and religious attitudes of Jordanian parents toward children born with orofacial clefts

Background and goalsParental attitudes towards orofacial clefts (OFC) can be influenced by culture. Interestingly, there are no studies up to date examined parental attitudes towards these congenital anomalies in Jordan. The objectives of this study were to 1) explore the social and religious attitudes of Jordanian parents toward their children born with OFCs, and 2) determine the predictors of social and religious beliefs and behaviors. Methods and settingsA descriptive study conducted at a tertiary care teaching hospital. Hundred and fifty-three parents participated in the study. All the participants completed the questionnaire were the biological either father or mother; (61) and (92) respectively. The patients with OFC were 95 males and 58 females ranged in age from 0.1 to 20 years (M = 8.2 years, SD = 6.4). The prevalence of OFC was characterized by 40 CL, 24 CP and 89 CLP. Patients’ gender and age, residence, other family incidences, and receiving health education about the cleft were the independent variables used in the binary regression to predict the social and religious beliefs. ResultsThe majority of the parental responses denied any social negativity in regard to the ability of their children to establish friendships, being hidden from the public, facing social difficulties. However, substantial parental concerns were found in regard to teasing and bullying (102 = 76.8%; p < 0.0001). No negative religious beliefs were observed. None of the independent variables showed significant relationships with the social beliefs except for “receiving health education about the cleft” which predicted the possibility of encountering “social difficulties” (B = 2.9; CI 3.2–100.5; p < 0.001; OR = 18.1). Regression model showed that parent with no education tended to hide the child (2.0%; St. Res = 3.4). Difficulty making friends was related to cleft lip type (Chi2 = 6.05; p < 0.05). Believing the deformity is because of an evil spirit” was related to cleft lip type (Chi2 = 6.6; p < 0.04). ConclusionsIrrespective to particular negative viewpoints observed among the parents towards OFCs, the majority of families tend to have positive social and religious beliefs. These affirmative constructs towards the cleft deformity may reflect positively on the provision of health care services. The establishment of an in depth family counseling and health education routine programs concerning the attributes of OFCs at a wider scale to maintain the integrity of parents’ beliefs of the OFC deformity may be warranted.

Risk indicators for syndromic and nonsyndromic orofacial clefts in Southern Province of Saudi Arabia

Objective: This study was designed to find out risk indicators for the development of orofacial clefts (OFCs) in the Southern Province of Saudi Arabia. Materials and Methods: This was a retrospective study carried out in a maternity hospital from January 2013 to December 2016. Data including child sex, type and site of cleft, birth weight and birth month (season), parents' age at the time of their child's birth, paternal and maternal habits, parental consanguinity, and family history of OFCs were obtained. The data were processed and analyzed using SPSS software, Version 20. Results: Overall prevalence of OFCs in the study population was 0.65/1000 live births. There were 10 males, 5 females, and 1 ambiguous sexual orientation. Of the 16 OFC patients, 9 (56.25%) were classified as having syndromic OFCs (SOFCs) and 7 (43.75%) as having non-SOFCs (NSOFCs). Cleft lip and cleft lip/palate both had strong family history of OFCs. Similarly, the phenotype of OFCs and the presence of syndromic or NSOFCs did not show a relationship with paternal smoking habits during pregnancy. No relationship was reported between parental consanguinity with the presence of these factors. However, results showed that 13 (81.3%) out of 16 identified cases of OFC had background consanguinity. Conclusion: Prevalence of OFC in the current study was within reported range, consanguinity was observed in 81.3% of identified cases. Further research is paramount in the role of consanguinity in OFC in Arabian population.

Maternal Exposure to Ozone and PM2.5 and the Prevalence of Orofacial Clefts in Four U.S. States

Introduction: Epidemiologic evidence of the association between maternal exposure to ambient air pollution and risk of orofacial clefts has been inconsistent. We evaluated whether maternal exposure...

Change in Prevalence of Orofacial Clefts in California between 1987 and 2010.

To extend the knowledge base about possible prevalence declines of specific orofacial cleft phenotypes, here we examine prevalence in a population base from California over a two-decade period among numerous race/ethnic groups. This population-based study used vital statistics and birth defects registry data. Its population involved all births (~1.5 million births) in central California counties from 1987 to 2010. Orofacial clefts were defined as cleft lip with or without cleft palate (CLP, n=1766), and cleft palate (CP, n=922) only. The slope of prevalence of each cleft phenotype over the period 1987-2010 was estimated using weighted least squares regression. Birth prevalence of CLP was 121/100,000 live births, and 63/100,000 live births for CP. The slope for CLP decreased by 1.2 (slope: -1.2; 95% CI: -1.9, -0.5), and for CP by 0.7 (slope: -0.7; 95% CI: -1.7, 0.2) for CP. Stratification by race/ethnicity or infant sex did not demonstrate a statistical difference in slopes. We observed a decline in the prevalence in CLP in all ethnic groups, however did not observe the same amount of decline in CP, perhaps due to antenatal screening.

Patterns of Orofacial Clefting in New York City From 1983 to 2010: Trends by Racial Background, Birthplace, and Public Health Strategies.

To determine the role of racial background, public health initiatives, and residence on the prevalence of orofacial clefts (OFCs) in New York City (NYC). Retrospective review of OFC cases from the New York State Congenital Malformations Registry. Patients born with an OFC and all live births to mothers residing in NYC between 1983 and 2010. Orofacial cleft birth prevalence by cleft type, race, and borough of maternal residence for each year and by time period around the implementation of public health interventions including folate supplementation. A total of 3557 cases were reviewed. The prevalence remained stable for cleft palate and cleft lip with or without cleft palate (CL ± P) in sequential time periods of the study. Among CL ± P cases, cleft lip prevalence decreased early in the study compared to increases in cleft lip and palate prevalence. For most years, the prevalence of OFCs was lower among African Americans than whites. A total of 12% to 26% of mothers in 4 of the NYC boroughs deliver outside of their borough of residence, choosing to give birth in Manhattan most often. No difference in OFC prevalence was shown in any of the 5 NYC boroughs. The period prevalence remained relatively stable during the time periods before and after the implementation of folate supplementation for OFCs in NYC. Prevalence of OFC subtypes was lower for most time periods during this study among African Americans compared to whites. Several factors may explain the choice of birthplace outside of the mother's borough of residence.

Burden of Orofacial Clefting in India, 2016: A Global Burden of Disease Approach.

Background:In the recent past, there have been inconsistent reports of India witnessing a decreasing trend in the incidence of orofacial clefts (OFC). To date, little comprehensive evidence has been published. To identify the prevalence, associated burden in terms of epidemiological parameters and to estimate the “unmet” OFC treatment needs, the present study was undertaken.Materials and Methods:Using the Global Burden of Diseases 2016 approach and its assumptions, an attempt was made to estimate the prevalence to quantify the burden of OFC in India as disability-adjusted life years (DALYs), years of life lost (YLL), and years lived with disability (YLD) as well as death due to OFC. The results from such an approach are presented. Using previous estimates of “unmet” OFC treatment needs, an attempt was made to estimate the current volume of “unmet” OFC treatment needs.Results:In the present study, it was estimated that a total of 0.033% of all Indian population suffers from OFC. In 2016, the estimated prevalence rate/100,000 was 33.27 for males, 31.01 for females, and 32.18 combined for both genders. It was estimated that for all ages, the DALYs lost were 2.05 for 100,000 males, 2.66 for females and 2.34 for both sexes. The OFC birth prevalence model revealed that the birth prevalence (as a proportion) in 2016 in India showed an odds ratio of 0.48 (1.56–1.65) and fixed factor of nonrecording 0.83 (0.15–6.63), underreporting 0.97 (0.88–1), gender 1.09 (1.02–1.16), chromosomal diagnoses included 1.22 (1.22–1.22), and stillbirth 1.22 (1.22–1.22). The total unmet cleft treatment need was estimated at 79,430 or 18.76% of the total Indian cleft population with OFC.Conclusions:Within the constraints of the mathematical modeling and based on all available surveys, literature, and reported data, the overall birth prevalence and the prevalence of OFC in India are presented. Till reliable data emerges, the present estimates could serve as a robust estimate of the prevalence and burden of OFC in India. The present enterprise highlights the need for well-designed, high-quality Pan-India, community-based, observational studies to accurately estimate the burden of OFC in India.

Prevalence and Incidence of Orofacial Cleft Anomalies in Children with Cleft Lip and Palate Associated with Etiological Deformities in Hail Region, Saudi Arabia

Aim: The aim of this study was to explore the prevalence, incidence and possible etiological risk factors of orofacial cleft in Hail Region, Northern Saudi Arabia. Methodology: This is a retrospective study conducted in Maternity Hospital, Hail, Saudi Arabia. Data of seven years (2011-2017) records of newborn infants were reviewed for the presence of orofacial anomalies (included 27800 files). Results: The overall prevalence rate of orofacial cleft was 1.08 per 1000 births. Out of 30 patients diagnosed with orofacial anomalies, 14(46.7%) were found with cleft palate, 11(36.7%) with bilateral cleft lip and palate, 4(13.3%) with bilateral cleft lip and only one (3.3%) with unilateral cleft lip and palate. Conclusion: The prevalence of orofacial clefts in Northern Saudi Arabia was similar or slightly lower than the higher global reported rates. Cleft palate was the most common type of orofacial cleft in Northern Saudi Arabia.

Prevalence of Orofacial Clefts among Live Births in China: A Systematic Review and Meta-Analysis.

Orofacial clefts (OFCs) are common human birth defects in China. However, studies on the prevalence of OFCs present inconsistent results. The overall prevalence and geographic distribution of OFCs are poorly described in China. Thus, we conducted a systematic review and meta-analysis to estimate the prevalence of OFCs. The systematic review and meta-analysis were conducted on the basis of an established protocol (PROSPERO 2015: CRD42015030198). We systematically searched for articles in four electronic databases, including Embase, PubMed, Wanfang Database, and China National Knowledge Infrastructure (CNKI) to identify relevant studies about prevalence of OFCs in China. Meta-analysis, including subgroup analysis, was conducted to estimate the pooled prevalence. A total of 41 studies published between 1986 and 2015 were included in our analysis. The sample size ranged from 2,586 to 4,611,808 live births. The random-effects model of meta-analysis showed that the overall prevalence of OFCs in China was 1.4 per 1000 live births (95% confidence interval [CI], 1.1-1.7). In subgroup analysis based on geographic regions, we found that OFC prevalence in Southwest (2.3 per 1000 live births, 95% CI, 1.1-4.7) was higher than that in other regions of China. There were no significant time trends of OFCs during the study period (p-value = 0.47). The overall prevalence of OFCs in China was 1.4 per 1000 live births. No significant secular trend of prevalence has been found in this analysis. Further studies need to be conducted to explore the etiology of OFC to better control the risk of this common birth defect. Birth Defects Research 109:1011-1019, 2017. © 2017 Wiley Periodicals, Inc.

Descriptive Epidemiology of Orofacial Clefts in Ethiopia.

The prevalence of birth defects including orofacial clefts (OFC) in Ethiopia is not known and there is no established birth defects registration system. To investigate the prevalence and incidence of OFC in Ethiopia. Retrospective hospital-based descriptive study. The authors obtained data from the Smile Train database on Ethiopian patients with OFC who underwent surgical treatment from June 2007 to December 2013 at 31 hospitals distributed throughout the country. Data related to live births in Ethiopia during the mentioned period were obtained from the Federal Ministry of Health database for estimates of the incidence and prevalence rates. The total number of life births during the study period was 18,811,316. During this same period, 18,073 cleft patients approximately ranging from 1 to 75 years old were examined and treated at the hospitals mentioned earlier. The incidence rate estimated from the total number of affected children during the study period (N = 8232) is 0.44/1000 live births. The prevalence rate is 0.20/1000 and this was estimated using the number of total population in 2013 (N = 88,703,914). There is a significant difference in frequency between bilateral clefts of the lip and/or palate (CLP) (26.9%) versus unilateral CLP (73.1%) (P < 0.0001). There is also a significant difference in frequency between bilateral cleft lips only (15.4%) versus unilateral cleft lip only (84.6%), P < 0001. It is obvious that the findings in this study cannot be representative of the true picture but provides a previously unavailable national estimate of incidence and prevalence of OFC in Ethiopia. It can also be used as comparison for future community-based studies.

Orofacial clefts in Brazil and surgical rehabilitation under the Brazilian National Health System

The objective of this study was to investigate the prevalence of live births with orofacial clefts in Brazil from 2009 to 2013, according to Brazil's federative units and regions, and correlate it with the number of corrective surgery procedures for cleft lip and palate performed through the Brazilian National Health System in the same period. The data were collected from the National Live Birth System (SINASC in Portuguese) and the Hospital Information System (SIH-SUS in Portuguese). The results showed that the average prevalence of oral clefts in the period was 5.86 per 10,000 live births, with differences observed between the federative units and the regions. The correlation between the prevalence of orofacial clefts and the number of medical procedures associated with this anomaly was statistically significant (r=0.94; p <0.001). This result indicates that greater investments are being made in areas with a higher number of cases. The relationship between supply and demand for corrective surgeries suggests that only 18.91% of the live births with orofacial clefts in this period may have received this service under the Brazilian National Health System.

Maternal exposure to ozone and PM2.5 and the prevalence of orofacial clefts in four U.S. states

BackgroundWhile there is some evidence that maternal exposure to ambient air pollution is associated with orofacial clefts in offspring, the epidemiologic studies have been largely equivocal. We evaluated whether maternal exposure to elevated county-level ambient fine particulate matter with aerodynamic diameter ≤2.5µm (PM2.5) and ozone during early gestation was associated with a higher prevalence of orofacial clefts. MethodsBirth data consisting of 4.7 million births from 2001 to 2007 were obtained from National Birth Defects Prevention Network for four states — Arizona, Florida, New York (excluding New York City), and Texas. The air pollution exposure assessment for gestational weeks 5–10 was based on county-level average concentrations of PM2.5 and ozone data generated using a Bayesian fusion model available through CDC's Environmental Public Health Tracking Network. Two outcomes were analyzed separately: cleft lip with or without cleft palate, cleft palate alone. In logistic regression analyses, we adjusted for factors that were suspected confounders or modifiers of the association between the prevalence of orofacial clefts and air pollution, i.e., infant sex, race-ethnicity, maternal education, smoking status during pregnancy, whether this was mother's first baby, maternal age. ResultsEach 10µg/m3 increase in PM2.5 concentration was significantly associated with cleft palate alone (OR =1.43, 95% CI: 1.11–1.86). There was no significant association between PM2.5 concentration and cleft lip with or without cleft palate. No associations were observed between ozone exposure and the two outcomes of orofacial clefts. ConclusionsOur study suggests that PM2.5 significantly increased the risk of cleft palate alone, but did not change the incidence of cleft lip with or without palate. Ozone levels did not correlate with incidence of orofacial clefts.

Maternal exposure to ozone and PM2.5 and the prevalence of orofacial clefts in four U.S. states

Maternal exposure to ozone and PM2.5 and the prevalence of orofacial clefts in four U.S. states