Revisiting the embryogenesis of lip and palate development

Association of Commonly Prescribed Antepartum Medications and Incidence of Orofacial Clefting

BackgroundPharmacologic agents are often used in the antepartum period, however, studies on their effect on fetal development are limited. Thus, this study aims to examine the effect of commonly prescribed antepartum medications on the development of orofacial clefting.MethodsUtilizing EPIC Cosmos deidentified data from approximately 180 US institutions was queried. Patients born between January 1, 2013, to January 1, 2023, were included. Eight OC cohorts were identified. Gestational medication use was identified by medications prescribed, provider-administered, or reported use by mothers. Medications used in at least 1 in 10,000 pregnancies were included in this analysis.ResultsA total of 12 098 newborns with available maternal pharmacologic data were born with any type of orofacial clefting. Prevalence for all oral clefts, any cleft palate, and any cleft lip were 20.56, 18.10, and 10.60 per 10 000 individuals, respectively. Notable significant exposures include most anticonvulsants, such as lamotrigine (OR1.33, CI 1.10-1.62), and topiramate (OR1.35, CI 1.13-1.62), as well as nearly all SSRIs/SNRIs, including fluoxetine (OR1.34, CI 1.19-1.51), sertraline (OR1.25, CI 1.16-1.34), and citalopram (OR1.28, CI 1.11-1.47). Corticosteroids were also correlated including dexamethasone (OR1.19, CI 1.12-1.27), and betamethasone (OR1.64, CI 1.55-1.73), as were antibiotics, including amoxicillin (OR1.22, CI 1.14-1.30), doxycycline (OR1.29, CI 1.10-1.52), and nitrofuran derivatives (OR1.10, CI 1.03-1.17).ConclusionNew associations between commonly prescribed antepartum medications and orofacial clefting were found. These findings should be confirmed as causality is not assessed in this report. Practitioners should be aware of the potential increased risk associated with these medications.

Options for Regenerative Treatment with Bone Grafts in Children with Anterior Lip/Palate Cleft-A Review

Anterior lip/palate cleft is a congenital deformity affecting the upper lip and palate, posing significant challenges in both aesthetic and functional aspects for children. Effective management of this condition is crucial for improving quality of life and ensuring normal development. This review aims to highlight the regenerative treatment options available for children with anterior lip/palate cleft, focusing on the use of bone grafts and other advanced dental procedures. A review of the current literature and clinical practices was conducted to identify and evaluate the most effective treatment options. Emphasis was placed on regenerative techniques, particularly the use of bone grafts. Advancements in regenerative dentistry offer promising outcomes for children with anterior lip/palate cleft. Bone grafts, combined with innovative techniques such as growth factors, stem cell therapy, and distraction osteogenesis, provide effective solutions for restoring function and aesthetics. A multidisciplinary approach is essential to ensure comprehensive care and optimal results for these patients.

Epidemiological analysis of the incidence of cleft lip and palate in relation to the radon concentration in the German Democratic Republic from 1980 to 1989

PURPOSE

Cleft lip and palate (CLP) can be attributed aetiologically to genetic and exogenous influences. A significant teratogenic potency is attributed to ionising radiation. In Germany, radon is the element most strongly involved in radiation levels on the earth's surface, although there are considerable geographical differences due to geological characteristics and mining. A correlation between regional radon concentrations and the incidence of cleft malformations and even abortions has not yet been systematically investigated.

MATERIAL AND METHODS

With the introduction of mandatory reporting of CLP (1967), a centralised register was available which depicts the incidences in the 15 districts of the German Democratic Republic (GDR) with their associated counties for the years. The time interval from 1980 to 1989 was analysed. The numbers of live births and stillbirths were obtained from the statistical yearbooks; the radon concentrations in the soil were sourced from the German Federal Office for Radiation Protection.

RESULTS

The birth rate decreased significantly with increasing radon exposure in the soil (r = -0.400; p < 0.001). At the same time, there was a statistically significant correlation between higher radon exposure and the number of cleft births (r = 0.068; p = 0.003). In addition, the number of stillbirths increased with higher radiation exposure (p < 0.001).

CONCLUSION

The study identified correlations between radon exposure in the soil and fertility. The results confirmed the suspected teratogenic and abortive potential of regionally elevated radon exposure.

A Large Multicenter Brazilian Case-Control Study Exploring Genetic Variations in Interferon Regulatory Factor 6 and the Risk of Nonsyndromic Cleft Lip With or Without Cleft Palate

Nonsyndromic cleft lip with or without cleft palate (NSCL ± P) is strongly associated with both environmental and genetic risk factors, but its genetic underpinnings remain partially known. While variants in interferon regulatory factor 6 (IRF6) are linked to NSCL ± P risk in populations from Asia and Europe, studies on the highly admixed Brazilian population are scarce and have produced ambiguous results. This study aimed to investigate the contribution of IRF6 variants to the risk of NSCL ± P. Five tag-single nucleotide polymorphisms (rs599021, rs2073485, rs2235375, rs7552506, and rs642961) were analyzed in a large multicenter cohort composed of 1006 patients with NSCL ± P and 942 healthy controls. Statistical analyses involved multiple logistic regression tests consideration the tri-hybrid genetic origin of the Brazilian population, under a Bonferroni p value correcting for multiple comparisons. The A allele (OR: 1.43, 95% CI: 1.22-1.67, p < 0.0001) and AA genotype (OR: 2.04, 95% CI: 1.46-2.86, p < 0.0001) frequencies of rs642961 were significantly associated with NSCL ± P risk. Stratified analyses indicated that the variant is associated with susceptibility to both nonsyndromic cleft lip only (NSCLO) and nonsyndromic cleft lip and palate (NSCLP). However, the association with NSCLO was primarily observed in patients with high African ancestry, whereas the association with NSCLP was predominantly seen in patients with high European ancestry. No significant associations were found for the other investigated variants. Our results support the notion that the IRF6 rs642961 variant represents a marker of susceptibility to NSCL ± P in the Brazilian population, and that genetic ancestry composition plays a central role in the association with the cleft type.

Readability of Online Patient Education Materials for Cleft Care: A Systematic Review and Meta-Analysis

ObjectiveTo evaluate the readability of online patient education materials (PEMs) for cleft lip and/or palate and assess their alignment with recommended readability levels.DesignThis study is a systematic review and meta-analysis.SettingLiterature search conducted in PubMed, Scopus, and Embase databases following PRISMA guidelines.MaterialsStudies evaluating online PEMs for cleft care with reported readability metrics, including Flesch-Kincaid Grade Level, Flesch Reading Ease, SMOG Index, or Gunning Fog Index.InterventionsAssessment of readability metrics of online PEMs and evaluation of artificial intelligence tools (eg, ChatGPT) for text simplification.Main Outcome Measure(s)Pooled readability estimates (eg, Flesch-Kincaid Grade Level, Flesch Reading Ease, SMOG Index, Gunning Fog Index), heterogeneity (I²), and confidence intervals (CIs).ResultsNine studies were included, consistently showing that PEMs exceed readability recommendations. Pooled estimates revealed a Flesch-Kincaid Grade Level of 9.48 (95% CI: 8.51-10.45), Flesch Reading Ease score of 52.98 (95% CI: 42.62-63.34), SMOG Index of 9.27 (95% CI: 5.97-12.57), and Gunning Fog Index of 9.94 (95% CI: 8.90-10.98). Heterogeneity was minimal (I² = 0%). Artificial intelligence tools like ChatGPT demonstrated potential in simplifying text to the recommended sixth-grade reading level but lacked usability and comprehension testing.ConclusionsOnline PEMs for cleft care are consistently written at reading levels too complex for the average caregiver, underscoring the need for improved readability and accessibility. Future research should focus on developing multimodal resources, conducting usability assessments, and including non-English materials to address global disparities in cleft care education.

Administration of Porphyromonas gingivalis in pregnant mice enhances glycolysis and histone lactylation/ADAM17 leading to cleft palate in offspring

Periodontal disease is a risk factor for many systemic diseases such as Alzheimer's disease and adverse pregnancy outcomes. Cleft palate (CP), the most common congenital craniofacial defect, has a multifaceted etiology influenced by complex genetic and environmental risk factors such as maternal bacterial or virus infection. A prior case-control study revealed a surprisingly strong association between maternal periodontal disease and CP in offspring. However, the precise relationship remains unclear. In this study, the relationship between maternal oral pathogen and CP in offspring was studied by sonicated P. gingivalis injected intravenously and orally into pregnant mice. We investigated an obvious increasing CP (12.5%) in sonicated P. gingivalis group which had inhibited osteogenesis in mesenchyme and blocked efferocytosis in epithelium. Then glycolysis and H4K12 lactylation (H4K12la) were detected to elevate in both mouse embryonic palatal mesenchyme (MEPM) cells and macrophages under P. gingivalis exposure which further promoted the transcription of metallopeptidase domain17 (ADAM17), subsequently mediated the shedding of transforming growth factor-beta receptor 1 (TGFBR1) in MEPM cells and mer tyrosine kinase (MerTK) in macrophages and resulted in the suppression of efferocytosis and osteogenesis in palate, eventually caused abnormalities in palate fusion and ossification. The abnormal efferocytosis also led to a predominance of M1 macrophages, which indirectly inhibited palatal osteogenesis via extracellular vesicles. Furthermore, pharmacological ADAM17 inhibition could ameliorate the abnormality of P. gingivalis-induced abnormal palate development. Therefore, our study extends the knowledge of how maternal oral pathogen affects fetal palate development and provides a novel perspective to understand the pathogenesis of CP.

Association of MSX1 gene polymorphisms and maxillary lateral incisor agenesis in Non-syndromic cleft lip and/or palate individuals

Background

To investigate the association between MSX1 gene polymorphisms and maxillary lateral incisor agenesis with and without Non Syndromic Cleft lip and palate (NSCL/P) in a South Indian population.

Methods

The study sample was divided into four groups: Group I: Twenty five Cleft lip and palate (NSCL/P) subjects with unilateral/bilateral congenitally missing maxillary lateral incisors, without agenesis of any other permanent teeth, Group II: Twenty five individuals with NSCL/P and a full complement of teeth, Group III: Twenty five non-cleft individuals with unilateral/bilateral congenitally missing maxillary lateral incisors and Control group: Twenty five healthy individuals with normal teeth development and without orofacial defects. MSX1 gene polymorphisms rs12532, rs1042484 and rs11726039 were genotyped by Sanger sequencing method with pre designed primer using ABI 3730 DNA sequencer. Associations were tested using Pearson Chi-square analysis.

Results

The three SNPs, rs12532, rs1042484 and rs11726039 of MSX1 gene exhibited polymorphism. rs12532 was associated with reduced risk of maxillary lateral incisor agenesis in NSCL/P subjects. rs1042484 had significant association with the NSCL/P without maxillary lateral incisor agenesis (full complement of teeth) subjects. rs11726039 showed significant association with NSCL/P with or without maxillary lateral incisor agenesis.

Conclusion

The present study on a South Indian population revealed a significant association between the MSX1 gene polymorphisms and tooth agenesis in NSCL/P subjects. Keywords: MSX1, non syndromic cleft lip and palate, lateral incisor agenesis.

5'tiRNA-35-GlyTCC-3 and 5'tiRNA-33-CysGCA-11 target BMP6, CUL1 and SPR of non-syndromic cleft palate

BACKGROUND

tsRNAs are novel small non-coding RNAs that play important regulatory roles in gene expression, translation, transcription, and epigenetic modification through proteins or mRNAs and may be therapeutic targets for certain diseases. The etiology of non-syndromic cleft palate-only is complex and the pathogenesis is poorly understood, non-coding RNAs play important roles in its development.

METHODS

The tsRNAs of patients with simple cleft palate were compared with healthy individuals using small RNA microarray, bioinformatic analysis, quantitative real-time transcription polymerase chain reaction, and the effects measured using immunohistochemical staining.

RESULTS

Seventy-nine tsRNAs were upregulated and fifty-four tsRNAs were downregulated in patients with simple cleft palate compared with healthy individuals, among which the expression of 5'tiRNA-35-GlyTCC-3 and 5'tiRNA-33-CysGCA-11 was markedly different and was involved in key signaling pathways related to the development of the palate, such as the cell cycle, cAMP signaling pathway, BMP signal transduction, folate biosynthesis, and other key signaling pathways that determine anatomical structure occurrence, regulate gene expression during development, influence epigenetics, and other biological processes, its target genes include BMP6, CUL1 and SPR.

CONCLUSION

5'tiRNA-35-GlyTCC-3 and 5'tiRNA-33-CysGCA-11 are closely associated with non-syndromic cleft palate development and are expected to be potential new targets for diagnosis and treatment.

A TAF11 variant contributes to non-syndromic cleft lip only through modulating neural crest cell migration

The NC_000006.12: g.34887814C>G variant in TAF11 was identified as a potential functional variant in a Chinese pedigree including two non-syndromic cleft lip only (NSCLO) cases. Applying Chromatin Immunoprecipitation (ChIP), Electrophoretic mobility shift and super-shift assays, we found that the mutant G allele recruited more STAT1 and STAT3, and increased the expression of TAF11. RNA sequencing, GO and KEGG pathway enrichment, ChIP and dual-luciferase reporter assays revealed that TAF11 downregulated CDH1 and CTNND1 in the cell adhesion pathway by binding to their promoter regions and inhibiting transcriptional activities. Alcian blue staining, time-lapse photography, whole-mount in situ hybridization, phospho-Histone H3 immunofluorescence and TUNEL assays indicated that TAF11 and taf11 overexpression (TAF11OE and taf11OE, respectively) contributed to disturbed migration of cranial neural crest cells and abnormal craniofacial development, as well as increased death and deformity rates in zebrafish. In conclusion, a functionally relevant TAF11 variant, affecting cell migration via modulating CDH1 and CTNND1, was associated with etiology of NSCLO.

Genome wide association study reveals novel associations with face morphology

Genome-wide association studies (GWAS) on the Middle Eastern population, including the United Arab Emirates (UAE), have been relatively limited. The present study aims to investigate genotype-face morphology associations in the UAE population through Genome Wide Association Studies (GWAS). Phenotypic data (44 face measurements) from 172 Emiratis was obtained through three-dimensional (3D) scanning technology and an automatic face landmarking technique. GWAS analysis revealed associations of 19 genetic loci with six face features, 14 of which are novel. The GWAS analysis revealed 11 significant relationships between 44 face parameters and 242 SNPs, exceeding the GWAS significance threshold. These phenotypes were previously associated with body height, craniofacial defects, and facial characters. The most significant associations of these genetic variations were related to six main facial features which were facial convexity, left orbital protrusion, mandibular contour, nasolabial angle D, inferior facial angle B, and inferior facial angle A. To the best of our knowledge, this is the first GWAS study to investigate the association of SNP variations with face morphology in the Middle Eastern population.

Molecular Regulation of Palatogenesis and Clefting: An Integrative Analysis of Genetic, Epigenetic Networks, and Environmental Interactions

Palatogenesis is a complex developmental process requiring temporospatially coordinated cellular and molecular events. The following review focuses on genetic, epigenetic, and environmental aspects directing palatal formation and their implication in orofacial clefting genesis. Essential for palatal shelf development and elevation (TGF-β, BMP, FGF, and WNT), the subsequent processes of fusion (SHH) and proliferation, migration, differentiation, and apoptosis of neural crest-derived cells are controlled through signaling pathways. Interruptions to these processes may result in the birth defect cleft lip and/or palate (CL/P), which happens in approximately 1 in every 700 live births worldwide. Recent progress has emphasized epigenetic regulations via the class of non-coding RNAs with microRNAs based on critically important biological processes, such as proliferation, apoptosis, and epithelial-mesenchymal transition. These environmental risks (maternal smoking, alcohol, retinoic acid, and folate deficiency) interact with genetic and epigenetic factors during palatogenesis, while teratogens like dexamethasone and TCDD inhibit palatal fusion. In orofacial cleft, genetic, epigenetic, and environmental impact on the complex epidemiology. This is an extensive review, offering current perspectives on gene-environment interactions, as well as non-coding RNAs, in palatogenesis and emphasizing open questions regarding these interactions in palatal development.

Maternal micronutrient biomarkers and risk of non-syndromic cleft lip/palate: A case-control study

OBJECTIVE

This case-control study investigated the associations between maternal plasma vitamin B12, homocysteine, and red blood cell (RBC) folate levels and the risk of cleft lip with or without cleft palate (CL/P) in offspring.

SUBJECTS AND METHODS

The study compared 94 mothers and children with non-syndromic CL/P from a teaching hospital in Thailand to 94 mother-infant controls from local well-baby clinics, frequency-matched by birth date and mother's education. Data included anthropometric measurements, blood sample analyses, and a questionnaire. Odds ratios (ORs) and 95% confidence intervals (CIs) estimated the associations through multiple logistic regression, adjusting for confounders.

RESULTS

Mothers with higher plasma vitamin B12 levels had a lower risk of having a child with CL/P compared to those in the lowest quartile. This association was more pronounced among mothers without a family history of orofacial clefts and those who were not underweight. Conversely, elevated homocysteine levels, a marker of impaired B vitamin metabolism, increased the risk of CL/P. No association was found between RBC folate and CL/P.

CONCLUSION

Higher maternal vitamin B12 levels are associated with a reduced risk of CL/P, while elevated homocysteine levels may increase the risk.

Family History of Nonsyndromic Orofacial Clefts: A Brazilian Multicenter Study

OBJECTIVE

To summarize the evidence on the relationship between hereditary family history and nonsyndromic orofacial clefts (NSOC) in patients from various Brazilian states.

METHODS

This cross-sectional multicenter study was conducted at six specialized orofacial cleft services across different regions of Brazil. The sample consisted of 1899 patients with NSOC, including cleft lip only (NSCLO), cleft palate only (NSCPO), and cleft lip and palate (NSCLP). Data were collected from clinical records between June 2023 and May 2024. Family history was classified as positive or negative, with additional details on the number of affected relatives, degree of kinship, and type of oral cleft. Statistical analysis was performed using SPSS version 27.0, with chi-square tests and z tests to assess associations between variables, and Student's t test to compare the mean number of affected relatives among cleft types.

RESULTS

Of 1899 patients, 52.6% had NSCLP, 24.11% had NSCPO, and 23.27% had NSCLO. NSCLP and NSCLO were more common in males, while NSCPO was more frequent in females. NSCLP and NSCLO showed similar rates of positive family history, whereas NSCPO had significantly fewer cases with hereditary links. Third-degree relatives were the most affected across all groups.

CONCLUSION

NSCLP and NSCLO showed a higher frequency in males and more cases of positive family history compared to NSCPO. Further studies are needed to explore the genetic basis of NSOC, particularly in genetically diverse populations like Brazil.

Palatal segment contributions to midfacial anterior-posterior growth

Anterior-posterior (A-P) elongation of the palate is a critical aspect of integrated midfacial morphogenesis. Reciprocal epithelial-mesenchymal interactions drive secondary palate elongation that is coupled to the periodic formation of signaling centers within the rugae growth zone (RGZ). However, the relationship between RGZ-driven morphogenetic processes, the differentiative dynamics of underlying palatal bone mesenchymal precursors, and the segmental organization of the upper jaw has remained enigmatic. A detailed ontogenetic study of these relationships is important because palatal segment growth is a critical aspect of normal midfacial growth, can produce dysmorphology when altered, and is a likely basis for evolutionary differences in upper jaw morphology. We completed a combined whole mount gene expression and morphometric analysis of normal murine palatal segment growth dynamics and resulting upper jaw morphology. Our results demonstrated that the first formed palatal ruga (ruga 1), found just posterior to the RGZ, maintained an association with important nasal, neurovascular and palatal structures throughout early midfacial development. This suggested that these features are positioned at a proximal source of embryonic midfacial directional growth. Our detailed characterization of midfacial morphogenesis revealed a one-to-one relationship between palatal segments and upper jaw bones during the earliest stages of palatal elongation. Growth of the maxillary anlage within the anterior secondary palate is uniquely coupled to RGZ-driven morphogenesis. This may help drive the unequaled proportional elongation of the anterior secondary palate segment prior to palatal shelf fusion. Our results also demonstrated that the future maxillary-palatine suture, approximated by the position of ruga 1 and consistently associated with the palatine anlage, formed predominantly via the posterior differentiation of the maxilla within the expanding anterior secondary palate. Our ontogenetic analysis provides a novel and detailed picture of the earliest spatiotemporal dynamics of intramembranous midfacial skeletal specification and differentiation within the context of the surrounding palatal segment A-P elongation and associated rugae formation.

A Newborn with Cleft Palate Associated with PTEN Hamartoma Tumor Syndrome

Background: PTEN hamartoma tumor syndrome (PHTS) has evolved into an umbrella term for a range of syndromes, characterized by loss-of-function variants in the phosphatase and tensin homolog (PTEN) tumor suppressor gene on chromosome 10q23.31. This can result in a lifelong tumor predisposition in patients. Often, the syndrome is diagnosed in early childhood because of macrocephaly, dermatological findings, or development delay. Since the correlation between phenotype and genotype is weak, and the penetrance is age-dependent, this poses the question of the appropriate timing of potentially invasive and burdensome examinations for early cancer detection. Case: The present report describes an infant with cleft palate associated with PHTS, a rare occurrence, though the initial report of Cowden syndrome already pointed to oromaxillofacial abnormalities. The recent pediatric literature is reviewed to assess which clinical symptoms should raise suspicion of PHTS and may then lead to early genetic counseling. Conclusion: Since the amount of prospective data remains limited, and the estimation of tumor risk during infancy and adulthood is very difficult, we advocate for early and broad genetic testing in suspected cases, to gain more insights into this rare disease and allow for better counseling for patients and their families.

Tooth Anomalies in Patients With Nonsyndromic Orofacial Cleft: A Systematic Review and Meta-Analysis

OBJECTIVE

To evaluate the frequency of tooth anomalies (TA) in the deciduous and permanent dentition of patients with nonsyndromic orofacial clefts (NSOC), both inside and outside the cleft area.

METHODS

The following databases were searched for the relevant literature: Cochrane, OVID, SciELO, Embase, Livivo, PubMed, Scopus, and Web of Science. The risk of bias was analyzed using the Joanna Briggs Institute. Fixed and random-effects meta-analysis was performed comparing the presence and absence of NSOC subtypes. The certainty of evidence was evaluated using the GRADE approach.

RESULTS

Out of 1939 articles identified, after applying the inclusion and exclusion criteria, a total of 75 articles were included (46 cohort and 29 case-control), including 27,703 patients (16,450 with NSOC and 11,253 healthy controls) from 34 countries. The meta-analyses revealed higher odds for tooth agenesis (ORNSOC: 3.72; p = 0.001) and macrodontia (ORNSOC: 8.04; p = 0.04) across the different cleft subtypes outside the cleft area compared with the control group in the permanent dentition, whereas the frequency of root dilaceration was significantly lower in nonsyndromic cleft lip only (NSCLO) (ORNSCLO: 0.38; p < 0.0001) and in nonsyndromic cleft lip and palate (NSCLP) (ORNSCLP: 0.44; 95% p < 0.0001). The results also demonstrated a higher risk of tooth agenesis (ORNSOC: 16.49; p < 0.0001), microdontia (ORNSOC: 17.14; p < 0.0001), macrodontia (ORNSOC: 10.41; p = 0.02), supernumerary tooth (ORNSOC: 10.03; p < 0.0001), and enamel hypoplasia (ORNSOC: 5.62; p < 0.0001) in the permanent dentition inside the cleft area of patients with NSOC. However, for the deciduous dentition, outside the cleft area, microdontia was the only TA significantly more frequent in patients with NSOC (ORNSOC: 6.24; p = 0.006) and nonsyndromic cleft palate only (NSCPO) (ORNSCPO: 8.45; p = 0.02) compared with the control group. TA associations varied across populations. In Europe, no significant associations were found for NSOC, while in Asia, strong associations were observed for NSCLP and NSCL ± P (ORNSCLP and NSCL±P: 139.19; p < 0.0001). In South America, significant associations were identified for NSCLP (ORNSCLP: 2.16; p < 0.0001), NSCL ± P (ORNSCL±P: 2.48; p < 0.0001), and NSOC (ORNSOC: 2.72; p < 0.0001). In North America, tooth agenesis was more frequent in NSCL ± P (ORNSCL±P: 4.75; p < 0.0001), though no significant associations were found for NSCLP or NSOC. In the cleft area, significant associations were observed in European populations for NSOC, including increased frequencies of tooth agenesis (ORNSOC: 19.57; p = 0.003) and supernumerary teeth (ORNSOC: 9.77; p < 0.0001). Asian populations showed similar patterns (ORNSOC: 19.23; p = 0.002), while no significant associations were noted in South America due to limited data. Root dilaceration remained less frequent in NSCLO (ORNSCLO: 0.38; p < 0.0001) and NSCLP (ORNSCLP: 0.44; p < 0.0001), with no associations identified for microdontia, taurodontism, supernumerary tooth, impacted tooth, or transposition.

CONCLUSION

The results confirm a higher frequency of TA in the permanent dentition of patients with NSOC compared to controls, regardless of cleft subtype. However, significant differences were observed depending on whether the TA occurred inside or outside the cleft area. Although only a limited number of studies were included, microdontia was the only TA significantly more prevalent in the cleft area of patients with NSOC in the deciduous dentition. Variations in the frequency of TA across populations highlight the complex interplay of genetic, environmental, and methodological factors influencing these associations. Despite these findings, the quality of the existing evidence is moderate, with limitations stemming from small sample sizes, methodological variations, and study heterogeneity. These results emphasize the importance of tailored dental management and early intervention strategies for individuals with different cleft subtypes to effectively address and mitigate the impact of these tooth anomalies on oral health and development.

Naso-alveolar Asymmetry in Unilateral Cleft Lip and Palate Patients-CT Analysis of the Paranasal Region

Secondary deformities to the midfacial area in adolescence and adulthood are common sequelae after primary cleft lip and palate repair and lead to significant functional, aesthetic and psychosocial challenges. Treatment for patients with normal occlusion or treated malocclusion and remaining midfacial hypoplasia includes autologous and alloplastic augmentation of the maxilla. Because of the great variation of deformities, accurate evaluation is essential for appropriate treatment planning. To provide insights in the altered midfacial anatomy in cleft patients, a retrospective computed tomography morphologic analysis of the anterior projection of the maxilla in the paranasal region, soft tissue thickness, and relation of soft tissue to bony landmarks was performed in adolescent, unilateral, non-syndromic complete cleft and palate patients. The anterior projection of the maxilla was very variable with the cleft side bone surface being more anterior relative to the non-cleft side in some patients. Soft tissue thickness was not significantly different between cleft and non-cleft side. The lateral distance from the most anterior point of the maxilla to subalare was significantly smaller on the cleft side as compared with the non-cleft side. The authors' study demonstrates that in cleft lip and palate patients midfacial anatomy with regards to maxilla projection at the pyriform aperture is very variable making accurate evaluation of the bone morphology and an individualized treatment plan a prerequisite for successful correction of nasomaxillary deformities.

Epidemiology of cleft lip and palate in Bhutan, 2015-2022

BACKGROUND

The epidemiology of cleft lip (CL) and cleft palate (CLP) has not previously been described in the context of the Bhutan and Bhutanese populations. Using National Birth Defects Surveillance Data and other vital statistics, we present the comprehensive epidemiology of the cleft lip and palate in Bhutan.

METHODOLOGY

The National Birth Defects Surveillance Data Registry from 2015 to 2022 is reviewed retrospectively, covering 8 years of birth defect surveillance in the country from records maintained with three referral hospitals in the country. The baseline prevalence and incidence of cleft lip and palate have been presented over the years. The incidence of cleft lip and palate was defined as the number of cases per 1000 live births. We used Poisson's regression to compute the incidence of cleft lip and palate. Pearson chi-square tests (χ2) were used to examine the associations of maternal and child characteristics with cleft lip and palate.

RESULTS

A total of 1401 newborns with various birth defects were born among the 89,078 live births from 2015 to 2022 in Bhutan. Of these, 122 (8.7%) constituted orofacial clefts. The prevalence of orofacial clefts tended to increase, with a period prevalence of 1.37 per 1000 live births. There were more cases in males (72) than in females (50). The incidence rate ratio ranged from 1.2 to 2.0 compared with the 2015 baseline year, indicating increased rates over time.

CONCLUSION

Orofacial clefts constituted 8.7% of total birth defects and 1.37 per 1000 live births over the years. The increasing prevalence trends and incidence rate ratios over the years underscore the importance of ongoing surveillance and interventions to address the burden of orofacial clefts in Bhutan.

CLINICAL TRIAL NUMBER

Not applicable.

Palatal segment contributions to midfacial anterior-posterior growth

Anterior-posterior (A-P) elongation of the palate is a critical aspect of integrated midfacial morphogenesis. Reciprocal epithelial-mesenchymal interactions drive secondary palate elongation that is coupled to the periodic formation of signaling centers within the rugae growth zone (RGZ). However, the relationship between RGZ-driven morphogenetic processes, the differentiative dynamics of underlying palatal bone mesenchymal precursors, and the segmental organization of the upper jaw has remained enigmatic. A detailed ontogenetic study of these relationships is important because palatal segment growth is a critical aspect of normal midfacial growth, can produce dysmorphology when altered, and is a likely basis for evolutionary differences in upper jaw morphology. We completed a combined whole mount gene expression and morphometric analysis of normal murine palatal segment growth dynamics and resulting upper jaw morphology. Our results demonstrated that the first formed palatal ruga (ruga 1), found just posterior to the RGZ, maintained an association with important nasal, neurovascular and palatal structures throughout early midfacial development. This suggested that these features are positioned at a proximal source of embryonic midfacial directional growth. Our detailed characterization of midfacial morphogenesis revealed a one-to-one relationship between palatal segments and upper jaw bones during the earliest stages of palatal elongation. Growth of the maxillary anlage within the anterior secondary palate is uniquely coupled to RGZ-driven morphogenesis. This may help drive the unequaled proportional elongation of the anterior secondary palate segment prior to palatal shelf fusion. Our results also demonstrated that the future maxillary-palatine suture, approximated by the position of ruga 1 and consistently associated with the palatine anlage, formed predominantly via the posterior differentiation of the maxilla within the expanding anterior secondary palate. Our ontogenetic analysis provides a novel and detailed picture of the earliest spatiotemporal dynamics of intramembranous midfacial skeletal specification and differentiation within the context of the surrounding palatal segment AP elongation and associated rugae formation.

Epithelial-mesenchymal crosstalk: the scriptwriter of craniofacial morphogenesis

Epithelial-mesenchymal interactions (EMI) are fundamental mechanisms in regulating development and organogenesis. Here we summarized the signaling mechanisms involved in EMI in the major developmental events during craniofacial morphogenesis, including neural crest cell induction, facial primordial growth as well as fusion processes. Regional specificity/polarity are demonstrated in the expression of most signaling molecules that usually act in a mutually synergistic/antagonistic manner. The underlying mechanisms of pathogenesis due to disrupted EMI was also discussed in this review.

Unbiased transcriptome analysis of human cleft palate reveals evolutionally conserved molecular signatures of development: experimental study

BACKGROUND

The development of the secondary palate, an essential process for hard palate formation, involves intricate cellular processes. Here, the authors examined the expression patterns of palatal fusion-associated genes in postdevelopmental human palatal tissues.

METHODS

Mucosal samples collected from the anterior fused (control; n =5) and posterior unfused regions (study; n =5) of cleft palate patients were subjected to RNA sequencing. Gene Set Enrichment Analysis (GSEA) was conducted to identify consistent changes in molecular signaling pathways using hallmark (h) gene set collections from the Molecular Signature Database v7.4. The results of RNA sequencing were validated by epithelial-mesenchymal transition (EMT) assays with suppression of target genes, including lrp6, shh, Tgfβ-3 (Bioneer), and negative control siRNA in a human fibroblast cell line (hs68).

RESULTS

Transcriptome profiling of the cleft mucosa demonstrated that the fully fused anterior mucosa exhibited globally upregulated EMT, Wnt β-catenin, Hedgehog, and TGF-β signaling pathways in gene set enrichment. This strongly indicates the evolutionary conserved similarities in pathways implicated in palatogenesis, as previously shown in murine models. In EMT assays with suppression of Lrp6, Shh, and TGF-β3 in human fibroblast cell lines, suppression of Lrp6 exhibited consistent suppression effects on EMT markers. This indicates a closer association with EMT compared to the other two signals.

CONCLUSION

Our study highlights evolutionarily conserved molecular signatures and provides insights into the importance of the EMT pathway in palatal fusion in humans. Furthermore, intraindividual comparative analysis showed the spatial regulation of gene expression within the same organism. Further research and animal models are needed to explore the complexities of EMT-related palatal fusion.

Ethnic Differences in the Brazilian Population Influence the Impact of BMP4 Genetic Variants on Susceptibility of Nonsyndromic Orofacial Clefts

OBJECTIVE

The study evaluated the association of BMP4 tag-SNPs and SNP-SNP interactions involving genes active by BMP4 pathway during craniofacial development in the susceptibility of nonsyndromic orofacial clefts (NSOC) in the Brazilian population.

DESIGN

Case-control study.

SETTING

Brazilian Oral Cleft Group.

PARTICIPANTS

The study included 881 healthy controls and 800 patients with different types of NSOC: 232 with cleft lip only (NSCLO), 568 with cleft lip and palate (NSCLP), and 274 with cleft palate only (NSCPO).

INTERVENTIONS

The genomic DNA was genotyped with allelic discrimination assays for five BMP4 tag-SNPs (rs11623717, rs17563, rs2071047, rs2761887 and rs4898820), and analyzed their allelic and genotypic associations using multiple logistic regression. The interactions of these variants with genes involved in the BMP4 signaling pathway, including FGFR1, GREM1, NOG, VAX1 and the 4p16.2 locus, were explored.

MAIN OUTCOME MEASURES

BMP4 variants in the NSOC risk.

RESULTS

Although only nominal p values were identified when the whole sample was considered, subgroup analysis including the patients with high African genomic ancestry showed significant associations of rs2761887 with risk for nonsyndromic cleft lip with or without cleft palate (NSCL  ±  P)[(ORhom: 2.16; 95% CI: 1.21-3.85; p  =  0.01) and (ORrec: 2.05; 95% CI: 1.21-3.47; p  =  0.006)]. Thirteen significant SNP-SNP interactions involving BMP4 and the SNPs at FGFR1, GREM1, NOG and VAX1 and at locus 4p16.2 for increased risk of NSCL  ±  P were identified.

CONCLUSIONS

Our results demonstrate an increased risk of NSCL  ±  P in Brazilian individuals with enrichment of African ancestry in the presence of the BMP4 rs2762887 polymorphism, and reveal relevant genetic contribution of SNP-SNP epistatic interactions involving BMP4 variants to NSCL  ±  P risk.

Reflecting the human lip in vitro: Cleft lip skin and mucosa keratinocytes keep their identities

OBJECTIVES

Cell models have shown great promise as tools for research, potentially providing intriguing alternatives to animal models. However, the original tissue characteristics must be maintained in culture, a fact that is often assumed, but seldom assessed. We aimed to follow the retention of the original tissue identities of cleft lip-derived skin and mucosa keratinocytes in vitro.

METHODS

Cleft lip-derived keratinocytes were isolated from discarded tissue along the cleft margins during cheiloplasty. Cell identities were assessed by immunohistochemistry and quantitative real-time PCR for tissue-specific markers and compared with native lip tissue. Moreover, keratinocytes were regularly analyzed for the retention of the original tissue characteristics by the aforementioned methods as well as by differentiation assays.

RESULTS

The various anatomical zones of the human lip could be distinguished using a panel of differentiation and functional-based markers. Using these markers, retention of the original tissue identities could be followed and confirmed in the corresponding primary keratinocytes in culture.

CONCLUSIONS

Our findings promote patient-derived cells retaining their original identities as astonishing and clinically relevant in vitro tools. Such cells allow a better molecular understanding of various lip-associated pathologies as well as their modeling in vitro, including but not restricted to orofacial clefts.

Risk of self-harm ideation in mothers of children with orofacial cleft defects: the Japan environment and children's study

Introduction

Cleft lip and/or palate (CL/P), the most prevalent congenital anomaly, has been associated with higher rates of child maltreatment. In particular, the presence of cleft lip has more of an impact on external appearance and may increase the risks of negative health outcomes such as parental postpartum depression; however, this concept remains controversial. Item #10 of the Edinburgh Postpartum Depression Scale is the assessment of parental self-harm ideation, and its presence in postpartum mothers merits risk assessments as an emergent issue that may affect the health of both mothers and infants. This study focused on the impact of CL/P on maternal self-harm ideation.

Methods

Of 100,300 live births from a nationwide birth cohort in Japan, 238 mothers of infants with CL/P [186 children born with cleft lip (CL ± P) and 52 born with isolated cleft palate (CP)] were included in the analyses. The prospective association of children with CL/P and maternal self-harm ideation, which were acquired using item #10 in the Edinburgh Postpartum Depression Scale at 1 and 6 months postpartum, was examined using binomial logistic regression analyses after multiple imputations and with adjustments for several maternal (age at delivery, smoking habit, and alcohol intake) and child-related (sex and prevalence of other congenital diseases) variables.

Results

The prevalence of self-harm ideation in 238 mothers of infants with CL/P at 1 and 6 months were 14.7% (35/238) and 18.8% (45/238) [8.2% (8,185/100,062) and 12.9% (12,875/100,062) in the control group], respectively. The odds ratio (95% confidence interval) for maternal self-harm ideation increased with CL/P prevalence [1.80 (1.22-2.65) and 1.47 (0.98-2.18)] at 1 and 6 months of age, respectively. After stratified by the prevalence of cleft lip, we found significant differences in the CL ± P group but not in the CP group. Furthermore, persistent self-harming ideation was associated with a higher risk in the CL ± P group [2.36 (1.43-3.89)].

Conclusion

CL/P, particularly cleft lip, which is more noticeable externally, was associated with an increased prevalence of maternal self-harm ideation. The findings in this study indicate some potential benefits of increasing support for mothers who have infants with CL/P.

Identification of novel genes regulating the development of the palate

The International Mouse Phenotyping Consortium (IMPC) has generated thousands of knockout mouse lines, many of which exhibit embryonic or perinatal lethality. Using micro-computed tomography (micro-CT), the IMPC has created and publicly released 3D image datasets of embryos from these lethal and subviable lines. In this study, we leveraged this dataset to screen homozygous null mutants for anomalies in secondary palate development. We analyzed optical sections from 2,987 embryos at embryonic days E15.5 and E18.5, representing 484 homozygous mutant lines. Our analysis identified 45 novel genes implicated in palatogenesis. Gene set enrichment analysis highlighted biological processes and pathways relevant to palate development and uncovered 18 genes jointly regulating the development of the eye and the palate. These findings present a valuable resource for further research, offer novel insights into the molecular mechanisms underlying palatogenesis, and provide important context for understanding the etiology of rare human congenital disorders involving simultaneous malformations of the palate and other organs, including the eyes, ears, kidneys, and lungs.

Simulation Training Approach for Cleft Lip and Palate Repair in Low-Income Countries

BACKGROUND

During periods of civil strife, the need for trauma care and lack of sufficient cleft surgeons causes an increase in children left untreated with cleft lip and palate deformities. During the Syrian war, some cleft care was provided through visiting charities, with surgeries performed both in Syria and neighboring countries. There is a need to increase the number of adequately trained cleft surgeons available in such regions so that care can be achieved beyond mission trips.

METHODOLOGY

Cleft lip and palate repair workshops were delivered to 50 doctors in Syria. Pre-workshop, trainees received supplementary learning material. During the workshop, attendees received didactic teaching followed by 2 simulation sessions. Pre- and post-workshop, attendees completed questionnaires regarding their confidence and ability to perform cleft lip and palate repair.

RESULTS

Pre-workshop, 96% of workshop attendees had never independently performed cleft lip repair while 100% of attendees had not previously performed cleft palate repair. The mean pre-workshop confidence score was 2.452. Post-workshop, the mean confidence score was 3.503. Confidence rating scores significantly improved (P < .001).

CONCLUSION

The workshop delivered in Syria, together with this cleft lip and palate simulator provides an effective training tool that may support surgical training globally, particularly those in low-income countries. Further support is needed by charity organizations to ensure the continued delivery of such training.

Exosomes Derived from Human Palatal Mesenchymal Cells Mediate Intercellular Communication During Palatal Fusion by Promoting Oral Epithelial Cell Migration

Purpose

Exosomes are important "messengers" in cell-cell interactions, but their potential effects on palatal fusion are still unknown. This study aimed to explore the role and mechanism of exosomes derived from palatal mesenchymal cells in epithelial-mesenchymal communication during palatogenesis.

Methods

The expression of exosome marker CD63 and CD81 in palatal cells during palatogenesis was detected by immunofluorescence staining. After being purified from the supernatant of human embryonic palatal mesenchymal (HEPM) cells, exosomes (HEPM-EXO) were characterized by nanoparticle tracking analysis (NTA), transmission electron microscopy (TEM) and Western blot. HEPM-EXO were co-cultured with human immortalized oral epithelial cells (HIOEC). The effects of HEPM-EXO on the cell proliferation, migration, apoptosis and epithelial-mesenchymal transition (EMT) of HIOEC were evaluated. The proteins encapsulated in HEPM-EXO were analyzed by proteomic analysis.

Results

The extensive expression of CD63 and CD81 in palatal epithelial and mesenchymal cells were continuously detected during E12.5~E14.5, suggesting that exosomes were involved in the process of palatal fusion. The expression of CD63 was also observed in the acellular basement membrane between the palatal epithelium and the mesenchyme in vivo, and HEPM-EXO could be internalized by HIOEC in vitro, suggesting that exosomes are potent to diffuse through the cellular tissue boundary to mediate palatal cell-cell communication. Exposure of HEPM-EXO to HIOEC substantially inhibited the proliferation and stimulated the migration of HIOEC, but had no significant effect on cell apoptosis and EMT. Proteomic analysis revealed the basic characteristics of the proteins in HEPM-EXO and that exosomal THBS1 may potentially regulate the cell behaviors of HIOEC, which needs further verification. Gene ontology (GO) analysis uncovered that the proteins highly expressed in HEPM-EXO are closely related to wound healing, implying a promising therapeutic opportunity of HEPM-EXO in tissue injury treatment with future studies.

Conclusion

HEPM-EXO mediated cell-cell communication by regulating cell proliferation and migration of oral epithelial cells during palatogenesis.

Exploring the role of the WNT5A rs566926 polymorphism and its interactions in non-syndromic orofacial cleft: a multicenter study in Brazil

BACKGROUND

Associations between the WNT5A rs566926 variant and non-syndromic orofacial cleft (NSOC) have been reported in different populations.

OBJECTIVE

This study aimed to investigate the role of the rs566926 single nucleotide polymorphism (SNP) in WNT5A and its interactions with SNPs in BMP4, FGFR1, GREM1, MMP2, and WNT3 in the occurrence of NSOC in a Brazilian population.

METHODOLOGY

A case-control genetic association study was carried out involving participants from four regions of Brazil, totaling 801 patients with non-syndromic cleft lip with or without cleft palate (NSCL±P), 273 patients with cleft palate only (NSCPO), and 881 health volunteers without any congenital condition (control). Applying TaqMan allelic discrimination assays, we evaluated WNT5A rs566926 in an ancestry-structured multiple logistic regression analysis, considering sex and genomic ancestry as covariates. Interactions between rs566926 and variants in genes involved in the WNT5A signaling pathway (BMP4, FGFR1, GREM1, MMP2, and WNT3) were also explored.

RESULTS

WNT5A rs566926 was significantly associated with an increased risk of NSCL±P, particularly due to a strong association with non-syndromic cleft lip only (NSCLO), in which the C allele increased the risk by 32% (OR: 1.32, 95% CI: 1.04-1.67, p=0.01). According to the proportions of European and African genomic ancestry, the association of rs566926 reached significant levels only in patients with European ancestry. Multiple interactions were detected between WNT5A rs566926 and BMP4 rs2071047, GREM1 rs16969681 and rs16969862, and FGFR1 rs7829058.

CONCLUSION

The WNT5A rs566926 polymorphism was associated with NSCL±P, particularly in individuals with NSCLO and high European ancestry. Epistatic interactions involving WNT5A rs566926 and variants in BMP4, GREM1, and FGFR1 may contribute to the risk of NSCL±P in the Brazilian population.

Role of TGF-β3 in modulating inflammatory responses and wound healing processes in ischemic ulcers in atherosclerotic patients

Ischemic ulcers pose a multifaceted clinical dilemma for patients with atherosclerosis, frequently compounded by suboptimal wound healing mechanisms. The dual function of Transforming Growth Factor Beta 3 (TGF-β3) in ischemic ulcer healing is not fully comprehended, despite its involvement in modulating inflammatory responses and tissue regeneration. The main aim of this investigation was to clarify the functions and mechanisms by which TGF-β3 regulates inflammatory responses and promotes wound healing in patients with ischemic ulcers who have atherosclerosis. Between August 2022 and November 2023, this cross-sectional investigation was conducted on 428 patients diagnosed with atherosclerotic ischemic ulcers in Haikou, China. The expression and function of TGF-β3 were examined throughout the different stages of wound healing, including inflammation, proliferation and remodelling. In addition to documenting patient demographics and ulcer characteristics, an analysis was conducted on biopsy samples to determine the expression of TGF-β3, pro-inflammatory and anti-inflammatory markers. A subset of patients were administered topical TGF-β3 in order to evaluate its therapeutic effects. The expression pattern of TGF-β3 was found to be stage-dependent and significant, exhibiting increased levels during the phase of inflammation and reduced activity in subsequent phases. TGF-β3 levels were found to be greater in ulcers that were larger and deeper, especially in inflammatory phase. TGF-β3 applied topically induced discernible enhancement in ulcer healing parameters, such as reduction in ulcer depth and size. The therapeutic significance of TGF-β3 was emphasised due to its twofold function of regulating the inflammatory environment and facilitating the regeneration of damaged tissues. Ischemic ulcer lesion healing is significantly influenced by TGF-β3, which functions as an anti-inflammatory and pro-inflammatory mediator. Its correlation with ulcer characteristics and stages of healing suggests that it may have utility as a targeted therapeutic agent.

Evidence-Based Practices in Cleft Palate Surgery

LEARNING OBJECTIVES

After studying this article, the participant should be able to: (1) Understand the embryologic origins, cause, and incidence of cleft palate. (2) Review the anatomy and common classifications of cleft palate and associated defects. (3) Describe surgical techniques for palatoplasty and understand their respective indications. (4) Gain an awareness of general perioperative care considerations, timing of repair, and risk factors for and operative mitigation of complications.

SUMMARY

Cleft palate affects 0.1 to 1.1 per 1000 births, with a higher incidence in certain ethnic groups but affecting both sexes equally. Cleft palate may occur in isolation or in combination with cleft lip or in association with other congenital anomalies including various syndromes. The goals of cleft palate repair are to anatomically separate the oral and nasal cavities for normal feeding and improved speech and minimize the risk of oronasal fistulas, velopharyngeal dysfunction, and disruption of facial growth. This review discusses the incidence, causes, and classification of cleft palate; surgical techniques for palatoplasty and perioperative patient management; and complications of palatoplasty.

The presence and distribution of various genes in postnatal CLP-affected palatine tissue

BACKGROUND

Worldwide cleft lip with or without a cleft palate (CL/P) is the most common craniofacial birth defect. Apart from changes in facial appearance, additionally affected individuals often suffer from various associated comorbidities requiring complex multidisciplinary treatment with overall high expenses. Understanding the complete pathogenetic mechanisms of CL/P might aid in developing new preventative strategies and therapeutic approaches, help with genetic counselling, and improve quality of life. Many genes have been associated with the development of orofacial clefts; however, the majority require further research. Based on the role of PAX7, PAX9, SHH, SOX3, WNT3A, and WNT9B in orofacial development, the intention was to use chromogenic in situ hybridization to detect the six genes in postnatal CLP-affected palatine tissue and compare their distribution within the tissue samples.

RESULTS

Statistically significant differences in the distribution of PAX7, PAX9, WNT3A, and WNT9B were observed. In total, 19 pairs of moderate to very strong positive correlations were noted.

CONCLUSIONS

Changes in the cleft-affected palatine epithelium primarily seem to be associated with the PAX7 gene; however, PAX9, WNT3A, WNT9B, and SOX3 role seems to be more limited. Whilst connective tissue changes seem to depend on PAX7 only, SHH seems to participate individually and indistinctly. Numerous positive correlations reflect the complicating interactions of the pathways and their components in the orofacial cleft morphopathogenesis.

Prevalence, trend, and associated risk factors for cleft lip with/without cleft palate: a national study on live births from 2016 to 2021

BACKGROUNDS

Cleft lip with or without cleft palate (CL/P) is the most common congenital craniofacial anomaly, including non-syndromic cleft lip with or without cleft palate and cleft palate only. Failure in the fusion of median and lateral nasal processes, the maxillary prominence, and soft tissues around the oral cavity can cause CL/P. Previously, the prevalence has been estimated to be 1 among every 1000 births in 2014 among American neonates and no other reports have been available since. Thus, this study aimed to calculate the prevalence and trend of isolated CL/P among American live births from 2016 to 2021 with its associated risk factors.

METHODS AND MATERIALS

In this cross-sectional population-based retrospective study, we used live birth data provided by the National Center for Health Statistics (NCHS) from the Center for Disease Control and Prevention (CDC). We calculated the prevalence per 10,000 live births of isolated (non-syndromic) CL/P from 2016 to 2021. To examine risk factors for developing isolated CL/P, we used logistic regression modelling.

RESULTS

The total prevalence per 10,000 births from 2016 to 2021 was 4.88 (4.79-4.97), for both sexes, and 5.96 (5.82-6.10) for males, and 3.75 (3.64-3.87) for females. The prevalence did not show any consistent linear decreasing or increasing pattern. We found significant association between increased odds of developing isolated CL/P among cases with 20 to 24 year-old mothers (OR = 1.07, 1.01-1.13, p = 0.013), mothers who smoked 11 to 20 cigarettes per day (OR = 1.46, 1.33-1.60, p <  0.001), mothers with extreme obesity (OR = 1.32, 1.21-1.43, p <  0.001), mothers with grade II obesity (OR = 1.32, 1.23-1.42, p <  0.001), mothers with pre-pregnancy hypertension (OR = 1.17, 1.04-1.31, p = 0.009), mothers with pre-pregnancy diabetes mellitus (OR = 1.96, 1.71-2.25, p <  0.001), and mothers who used assisted reproductive technology (OR = 1.40, 1.18-1.66, p <  0.001).

CONCLUSIONS

Our findings suggest a minuscule increase, albeit insignificant, in the trend of CL/P prevalence from 2016 to 2021. Developing CL/P had greater odds among mothers with pre-pregnancy diabetes, smoking, obesity, and pre-pregnancy hypertension mothers along with mothers who used assisted reproductive technology. Isolated CL/P had the highest prevalence in non-Hispanic Whites, American Indian or Alaskan Native and Native Hawaiian and Other Pacific Islanders.

MicroRNAs in Small Extracellular Vesicles from Amniotic Fluid and Maternal Plasma Associated with Fetal Palate Development in Mice

Cleft palate (CP) is a common congenital birth defect. Cellular and morphological processes change dynamically during palatogenesis, and any disturbance in this process could result in CP. However, the molecular mechanisms steering this fundamental phase remain unclear. One study suggesting a role for miRNAs in palate development via maternal small extracellular vesicles (SEVs) drew our attention to their potential involvement in palatogenesis. In this study, we used an in vitro model to determine how SEVs derived from amniotic fluid (ASVs) and maternal plasma (MSVs) influence the biological behaviors of mouse embryonic palatal mesenchyme (MEPM) cells and medial edge epithelial (MEE) cells; we also compared time-dependent differential expression (DE) miRNAs in ASVs and MSVs with the DE mRNAs in palate tissue from E13.5 to E15.5 to study the dynamic co-regulation of miRNAs and mRNAs during palatogenesis in vivo. Our results demonstrate that some pivotal biological activities, such as MEPM proliferation, migration, osteogenesis, and MEE apoptosis, might be directed, in part, by stage-specific MSVs and ASVs. We further identified interconnected networks and key miRNAs such as miR-744-5p, miR-323-5p, and miR-3102-5p, offering a roadmap for mechanistic investigations and the identification of early CP biomarkers.

Identification of an adverse outcome pathway (AOP) for chemical-induced craniofacial anomalies using the transgenic zebrafish model

Craniofacial anomalies are one of the most frequent birth defects worldwide and are often caused by genetic and environmental factors such as pharmaceuticals and chemical agents. Although identifying adverse outcome pathways (AOPs) is a central issue for evaluating the teratogenicity, the AOP causing craniofacial anomalies has not been identified. Recently, zebrafish has gained interest as an emerging model for predicting teratogenicity because of high throughput, cost-effectiveness and availability of various tools for examining teratogenic mechanisms. Here, we established zebrafish sox10-EGFP reporter lines to visualize cranial neural crest cells (CNCCs) and have identified the AOPs for craniofacial anomalies. When we exposed the transgenic embryos to teratogens that were reported to cause craniofacial anomalies in mammals, CNCC migration and subsequent morphogenesis of the first pharyngeal arch were impaired at 24 hours post-fertilization. We also found that cell proliferation and apoptosis of the migratory CNCCs were disturbed, which would be key events of the AOP. From these results, we propose that our sox10-EGFP reporter lines serve as a valuable model for detecting craniofacial skeletal abnormalities, from early to late developmental stages. Given that the developmental process of CNCCs around this stage is highly conserved between zebrafish and mammals, our findings can be extrapolated to mammalian craniofacial development and thus help in predicting craniofacial anomalies in human.

Craniofacial developmental biology in the single-cell era

The evolution of a unique craniofacial complex in vertebrates made possible new ways of breathing, eating, communicating and sensing the environment. The head and face develop through interactions of all three germ layers, the endoderm, ectoderm and mesoderm, as well as the so-called fourth germ layer, the cranial neural crest. Over a century of experimental embryology and genetics have revealed an incredible diversity of cell types derived from each germ layer, signaling pathways and genes that coordinate craniofacial development, and how changes to these underlie human disease and vertebrate evolution. Yet for many diseases and congenital anomalies, we have an incomplete picture of the causative genomic changes, in particular how alterations to the non-coding genome might affect craniofacial gene expression. Emerging genomics and single-cell technologies provide an opportunity to obtain a more holistic view of the genes and gene regulatory elements orchestrating craniofacial development across vertebrates. These single-cell studies generate novel hypotheses that can be experimentally validated in vivo. In this Review, we highlight recent advances in single-cell studies of diverse craniofacial structures, as well as potential pitfalls and the need for extensive in vivo validation. We discuss how these studies inform the developmental sources and regulation of head structures, bringing new insights into the etiology of structural birth anomalies that affect the vertebrate head.

Genetic Inheritance Models of Non-Syndromic Cleft Lip with or without Palate: From Monogenic to Polygenic

Non-syndromic cleft lip with or without palate (NSCL/P) is a prevalent birth defect that affects 1/500-1/1400 live births globally. The genetic basis of NSCL/P is intricate and involves both genetic and environmental factors. In the past few years, various genetic inheritance models have been proposed to elucidate the underlying mechanisms of NSCL/P. These models range from simple monogenic inheritance to more complex polygenic inheritance. Here, we present a comprehensive overview of the genetic inheritance model of NSCL/P exemplified by representative genes and regions from both monogenic and polygenic perspectives. We also summarize existing association studies and corresponding loci of NSCL/P within the Chinese population and highlight the potential of utilizing polygenic risk scores for risk stratification of NSCL/P. The potential application of polygenic models offers promising avenues for improved risk assessment and personalized approaches in the prevention and management of NSCL/P individuals.

Osteogenic microenvironment affects palatal development through glycolysis

Palate development involves various events, including proliferation, osteogenic differentiation, and epithelial-mesenchymal transition. Disruption of these processes can result in the cleft palate (CP). Mouse embryonic palatal mesenchyme (MEPM) cells are commonly used to explore the mechanism of palatal development and CP. However, the role of the microenvironment in the biological properties of MEPM cells, which undergoes dynamic changes during palate development, is rarely reported. In this study, we investigated whether there were differences between the palatal shelf mesenchyme at different developmental stages. Our results found that the palatal shelves facilitate proliferation at the early palate stage at mouse embryonic day (E) 13.5 and the tendency towards osteogenesis at E15.5, the late palate development stage. And the osteogenic microenvironment, which was mimicked by osteogenic differentiation medium (OIM), affected the biological properties of MEPM cells when compared to the routine medium. Specifically, MEPM cells showed slower proliferation, shorter S phase, increased apoptosis, and less migration distance after osteogenesis. E15.5 MEPM cells were more sensitive than E13.5, showing an earlier change. Moreover, E13.5 MEPM cells had weaker osteogenic ability than E15.5, and both MEPM cells exhibited different Lactate dehydrogenase A (LDHA) and Cytochrome c (CytC) expressions in OIM compared to routine medium, suggesting that glycolysis might be associated with the influence of the osteogenic microenvironment on MEPM cells. By comparing the stemness of the two cells, we investigated that the stemness of E13.5 MEPM cells was stronger than that of E15.5 MEPM cells, and E15.5 MEPM cells were more like differentiated cells than stem cells, as their capacity to differentiate into multiple cell fates was reduced. E13.5 MEPM cells might be the precursor cells of E15.5 MEPM cells. Our results enriched the understanding of the effect of the microenvironment on the biological properties of E13.5 and E15.5 MEPM cells, which should be considered when using MEPM cells as a model for palatal studies in the future.

A non-coding insertional mutation of Grhl2 causes gene over-expression and multiple structural anomalies including cleft palate, spina bifida and encephalocele

Orofacial clefts, including cleft lip and palate (CL/P) and neural tube defects (NTDs) are among the most common congenital anomalies, but knowledge of the genetic basis of these conditions remains incomplete. The extent to which genetic risk factors are shared between CL/P, NTDs and related anomalies is also unclear. While identification of causative genes has largely focused on coding and loss of function mutations, it is hypothesized that regulatory mutations account for a portion of the unidentified heritability. We found that excess expression of Grainyhead-like 2 (Grhl2) causes not only spinal NTDs in Axial defects (Axd) mice but also multiple additional defects affecting the cranial region. These include orofacial clefts comprising midline cleft lip and palate and abnormalities of the craniofacial bones and frontal and/or basal encephalocele, in which brain tissue herniates through the cranium or into the nasal cavity. To investigate the causative mutation in the Grhl2Axd strain, whole genome sequencing identified an approximately 4 kb LTR retrotransposon insertion that disrupts the non-coding regulatory region, lying approximately 300 base pairs upstream of the 5' UTR. This insertion also lies within a predicted long non-coding RNA, oriented on the reverse strand, which like Grhl2 is over-expressed in Axd (Grhl2Axd) homozygous mutant embryos. Initial analysis of the GRHL2 upstream region in individuals with NTDs or cleft palate revealed rare or novel variants in a small number of cases. We hypothesize that mutations affecting the regulation of GRHL2 may contribute to craniofacial anomalies and NTDs in humans.

Inhibition of Cxcr4 Disrupts Mouse Embryonic Palatal Mesenchymal Cell Migration and Induces Cleft Palate Occurrence

Many processes take place during embryogenesis, and the development of the palate mainly involves proliferation, migration, osteogenesis, and epithelial-mesenchymal transition. Abnormalities in any of these processes can be the cause of cleft palate (CP). There have been few reports on whether C-X-C motif chemokine receptor 4 (CXCR4), which is involved in embryonic development, participates in these processes. In our study, the knockdown of Cxcr4 inhibited the migration of mouse embryonic palatal mesenchymal (MEPM) cells similarly to the use of its inhibitor plerixafor, and the inhibition of cell migration in the Cxcr4 knockdown group was partially reversed by supplementation with C-X-C motif chemokine ligand 12 (CXCL12). In combination with low-dose retinoic acid (RA), plerixafor increased the incidence of cleft palates in mice by decreasing the expression of Cxcr4 and its downstream migration-regulating gene Rac family small GTPase 1 (RAC1) mediating actin cytoskeleton to affect lamellipodia formation and focal complex assembly and ras homolog family member A (RHOA) regulating the actin cytoskeleton to affect stress fiber formation and focal complex maturation into focal adhesions. Our results indicate that the disruption of cell migration and impaired normal palatal development by inhibition of Cxcr4 expression might be mediated through Rac1 with RhoA. The combination of retinoic acid and plerixafor might increase the incidence of cleft palate, which also provided a rationale to guide the use of the drug during conception.

Gene Regulatory Networks and Signaling Pathways in Palatogenesis and Cleft Palate: A Comprehensive Review

Palatogenesis is a complex and intricate process involving the formation of the palate through various morphogenetic events highly dependent on the surrounding context. These events comprise outgrowth of palatal shelves from embryonic maxillary prominences, their elevation from a vertical to a horizontal position above the tongue, and their subsequent adhesion and fusion at the midline to separate oral and nasal cavities. Disruptions in any of these processes can result in cleft palate, a common congenital abnormality that significantly affects patient's quality of life, despite surgical intervention. Although many genes involved in palatogenesis have been identified through studies on genetically modified mice and human genetics, the precise roles of these genes and their products in signaling networks that regulate palatogenesis remain elusive. Recent investigations have revealed that palatal shelf growth, patterning, adhesion, and fusion are intricately regulated by numerous transcription factors and signaling pathways, including Sonic hedgehog (Shh), bone morphogenetic protein (Bmp), fibroblast growth factor (Fgf), transforming growth factor beta (Tgf-β), Wnt signaling, and others. These studies have also identified a significant number of genes that are essential for palate development. Integrated information from these studies offers novel insights into gene regulatory networks and dynamic cellular processes underlying palatal shelf elevation, contact, and fusion, deepening our understanding of palatogenesis, and facilitating the development of more efficacious treatments for cleft palate.

Isolated nonsyndromic cleft palate: multicenter epidemiological study in the Brazil

BACKGROUND

Nonsyndromic orofacial clefts (NSOC) are the craniofacial most common congenital malformations. There are evidences that the nonsyndromic cleft palate (NSCP) development differs from other NSOC. However, most of the publications treat NSCP without considering that information. Furthermore, few studies focus on NSCP. The aim of this study was to describe epidemiological findings of patients with isolated NSCP in Brazil.

METHODS

In this cross-sectional multicenter study, four reference Centers for treatment in three different Brazilian states was investigated. Data were obtained from clinical records of patients, between November 2021 and June 2022. Researched variables were sociodemographic, clinical characteristics and pregnancy and family history. Pearson's chi-square and ANOVA One-way tests were used for associations.

RESULTS

Majority were female (58.1%), white (60.7%) with incomplete NSCP (61.2%). There was an association between complete NSCP and a positive history of medical problems during pregnancy (p = 0.016; 27.9%; OR: 1.94; 1.12-3.35). Systemic alterations were perceived in 40.6% of the sample with odds ratio for development of the complete type (OR: 1.21; 0.74-1.97). Higher OR was visualized in medication use during pregnancy (OR: 1.35; 0.76-2.37) and positive family history of oral cleft (OR: 1.44; 0.80-2.55). Dental and surgical care was associated with higher age groups (p < 0.050).

CONCLUSIONS

NSCP was most prevalent in white skin color female. Complete NSCP is associated with medical problems during pregnancy. Medication use during pregnancy and positive family history of oral cleft increase the chance of developing complete NSCP.

An essential overview of orofacial clefting

An appreciation of the embryologic development of the face is essential to understanding the anatomic variation observed in this phenotypically broad condition. Embryologically, the nose, lip and palate are separated into the primary and secondary palate, which are divided anatomically by the incisive foramen. The epidemiology of orofacial clefting is reviewed together with the contemporaneous cleft classification systems that enable comparisons to be made between international centres for audit and research purposes. A detailed examination of the clinical anatomy of the lip and palate informs the surgical priorities for the primary reconstruction of both form and function. The pathophysiology of the submucous cleft palate is also explored. The seismic impact of the 1998 Clinical Standards Advisory Group report on the organisation of UK cleft care provision is outlined. The importance of the Cleft Registry and Audit Network database in auditing UK cleft outcomes is highlighted. The potential for the Cleft Collective study to establish the causes of clefting, the optimal treatment protocols, and the impact of cleft on patients is tremendously exciting for all health care professionals involved in the management of this challenging congenital deformity.

Characterizing the microbiota of cleft lip and palate patients: a comprehensive review

Orofacial cleft disorders, including cleft lip and/or palate (CL/P), are one of the most frequently-occurring congenital disorders worldwide. The health issues of patients with CL/P encompass far more than just their anatomic anomaly, as patients with CL/P are prone to having a high incidence of infectious diseases. While it has been previously established that the oral microbiome of patients with CL/P differs from that of unaffected patients, the exact nature of this variance, including the relevant bacterial species, has not been fully elucidated; likewise, examination of anatomic locations besides the cleft site has been neglected. Here, we intended to provide a comprehensive review to highlight the significant microbiota differences between CL/P patients and healthy subjects in various anatomic locations, including the teeth inside and adjacent to the cleft, oral cavity, nasal cavity, pharynx, and ear, as well as bodily fluids, secretions, and excretions. A number of bacterial and fungal species that have been proven to be pathogenic were found to be prevalently and/or specifically detected in CL/P patients, which can benefit the development of CL/P-specific microbiota management strategies.

Brazilian Multiethnic Association Study of Genetic Variant Interactions among FOS, CASP8, MMP2 and CRISPLD2 in the Risk of Nonsyndromic Cleft Lip with or without Cleft Palate

Associations of CRISPLD2 (cysteine-rich secretory protein LCCL domain containing 2) and genes belonging to its activation pathway, including FOS (Fos proto-oncogene), CASP8 (caspase 8) and MMP2 (matrix metalloproteinase 2), with nonsyndromic orofacial cleft risk, have been reported, but the results are yet unclear. The aim of this study was to evaluate single nucleotide polymorphisms (SNPs) in FOS, CASP8 and MMP2 and to determine their SNP-SNP interactions with CRISPLD2 variants in the risk of nonsyndromic cleft lip with or without cleft palate (NSCL±P) in the Brazilian population. The SNPs rs1046117 (FOS), rs3769825 (CASP8) and rs243836 (MMP2) were genotyped using TaqMan allelic discrimination assays in a case-control sample containing 801 NSCL±P patients (233 nonsyndromic cleft lip only (NSCLO) and 568 nonsyndromic cleft lip and palate (NSCLP)) and 881 healthy controls via logistic regression analysis adjusted for the effects of sex and genomic ancestry proportions with a multiple comparison p value set at ≤0.01. SNP-SNP interactions with rs1546124, rs8061351, rs2326398 and rs4783099 in CRISPLD2 were performed with the model-based multifactor dimensionality reduction test complemented with a 1000 permutation-based strategy. Although the association between FOS rs1046117 and risk of NSCL±P reached only nominal p values, NSCLO risk was significantly higher in carriers of the FOS rs1046117 C allele (OR: 1.28, 95% CI: 1.10-1.64, p = 0.004), TC heterozygous genotype (OR: 1.59, 95% CI: 1.16-2.18, p = 0.003), and in the dominant model (OR: 1.50, 95% CI: 1.10-2.02, p = 0.007). Individually, no significant associations between cleft risk and the SNPs in CASP8 and MMP2 were observed. SNP-SNP interactions involving CRISPLD2 variants and rs1046117 (FOS), rs3769825 (CASP8) and rs243836 (MMP2) yielded several significant p values, mostly driven by FOS rs1046117 and CASP8 rs3769825 in NSCL±P, FOS rs1046117 in NSCLO and CRISPLD2 rs8061351 in NSCLP. Our study is the first in the Brazilian population to reveal the association of FOS rs1046117 with NSCLO risk, and to support that CRISPLD2, CASP8, FOS and MMP2 interactions may be related to the pathogenesis of this common craniofacial malformation.

Gene-environment interactions in the pathogenesis of common craniofacial anomalies

Craniofacial anomalies often exhibit phenotype variability and non-mendelian inheritance due to their multifactorial origin, involving both genetic and environmental factors. A combination of epidemiologic studies, genome-wide association, and analysis of animal models have provided insight into the effects of gene-environment interactions on craniofacial and brain development and the pathogenesis of congenital disorders. In this chapter, we briefly summarize the etiology and pathogenesis of common craniofacial anomalies, focusing on orofacial clefts, hemifacial microsomia, and microcephaly. We then discuss how environmental risk factors interact with genes to modulate the incidence and phenotype severity of craniofacial anomalies. Identifying environmental risk factors and dissecting their interaction with different genes and modifiers is central to improved strategies for preventing craniofacial anomalies.