Fisura labio palatina: revisión de la literatura / Cleft lip and palate: literature review

La formación del paladar ocurre entre la quinta y undécima semana de vida intrauterina producto de la unión del paladar primario y secundario. Por otra parte, la formación del labio superior ocurre entre la quinta y sexta semana del desarrollo, y se configura en su parte media por la fusión de los procesos nasales mediales y lateralmente, a expensas de los procesos maxilares. La prevalencia de las fisuras labiales y/o fisura palatina varía según las distintas etnias, con cifras entre 0,7 hasta 1,1 casos por 1000 nacidos vivos. El objetivo de este trabajo fue realizar una revisión bibliográfica sobre aspectos epidemiológicos, mecanismos genéticos moleculares y ambientales que influyen en la ocurrencia de la fisura labial, fisura palatina y fisura labio palatina. La búsqueda bibliográfica se realizó en las bases de datos PUBMED, SCOPUS, SPRINGER, SCIENCEDIRECT utilizando los términos en inglés "cleft lip and palate", "cleft lip", "cleft palate" y "embriology". Entre los criterios de inclusión se consideraron estudios realizados en humanos y animales, publicados entre los años 2015 y 2021. La búsqueda arrojó un total de 407 trabajos, de los cuales tras un filtro por título y resumen quedaron un total de 38 artículos, en los cuales se realizó un análisis de texto completo para finalmente seleccionar 26 artículos que abarcan temas genéticos-moleculares, ambientales, epidemiológicos y sindrómicos. Además se incorporaron por búsqueda manual, 6 documentos asociados a libros de texto, y artículos científicos, sin considerar el criterio inclusión de tiempo. Dentro de esta revisión se describe la fuerte asociación entre las fisuras orales y las mutaciones de genes Msx1, sonic hedgehog, proteínas morfogenéticas óseas y factor de crecimiento fibroblástico durante la migración de las células de la cresta neural y la modelación y formación del paladar. La ausencia de ácido fólico durante el desarrollo del paladar y la presencia de hipoxia por exposición a humo, son los factores ambientales observados con mayor frecuencia en malformaciones orofaciales.

SUMMARY: Palate formation occurs between the fifth and eleventh week of intrauterine life as a result of the union of the primary and secondary palate. On the other hand, the formation of the upper lip occurs between the fifth and sixth week of development, and is configured in its middle part by the fusion of the medial and lateral nasal processes, at the expense of the maxillary processes. The prevalence of cleft lips and / or cleft palate varies according to the different ethnic groups, with figures ranging from 0.7 to 1.1 cases per 1000 live births. The aim of this work was to carry out a literature review on epidemiological aspects, molecular and environmental genetic mechanisms that influence the occurrence of cleft lip, cleft palate and its embriology. The literature search was carried out in the databases PUBMED, SCOPUS, SPRINGER, SCIENCEDIRECT using the English terms "cleft lip and palate", "cleft lip", "cleft palate" and "embryology". Inclusion criteria included studies carried out in humans and animals, published between 2015 and 2021. The search yielded a total of 407 works, of which after a filter by title and abstract, a total of 38 articles remained, in which a text analysis was carried out complete to finally select 26 articles that cover genetic-molecular, environmental, epidemiological and syndromic topics. In addition, 6 documents associated with textbooks and scientific articles were incorporated by manual search, without considering the inclusion criterion of time. This review describes the strong association between oral fissures and mutations of genes Msx1, sonic hedgehog, bone morphogenetic proteins and fibroblast growth factor during migration of neural crest cells and palate shaping and formation. Lack of folic acid during palae development dar and the presence of hypoxia due to exposure to smoke, are the environmental factors most frequently observed in orofacial malformations.

RERE deficiency contributes to the development of orofacial clefts in humans and mice.

Deletions of chromosome 1p36 are the most common telomeric deletions in humans and are associated with an increased risk of orofacial clefting. Deletion/phenotype mapping, combined with data from human and mouse studies, suggests the existence of multiple 1p36 genes associated with orofacial clefting including SKI, PRDM16, PAX7 and GRHL3. The arginine-glutamic acid dipeptide (RE) repeats gene (RERE) is located in the proximal critical region for 1p36 deletion syndrome and encodes a nuclear receptor co-regulator. Pathogenic RERE variants have been shown to cause neurodevelopmental disorder with or without anomalies of the brain, eye or heart (NEDBEH). Cleft lip has previously been described in one individual with NEDBEH. Here we report the first individual with NEDBEH to have a cleft palate. We confirm that RERE is broadly expressed in the palate during mouse embryonic development, and we demonstrate that the majority of RERE-deficient mouse embryos on C57BL/6 background have cleft palate. We go on to show that ablation of Rere in cranial neural crest (CNC) cells, mediated by a Wnt1-Cre, leads to delayed elevation of the palatal shelves and cleft palate and that proliferation of mesenchymal cells in the palatal shelves is significantly reduced in Rereflox/flox; Wnt1-Cre embryos. We conclude that loss of RERE function contributes to the development of orofacial clefts in individuals with proximal 1p36 deletions and NEDBEH and that RERE expression in CNC cells and their derivatives is required for normal palatal development.

The molecular anatomy of mammalian upper lip and primary palate fusion at single cell resolution.

The mammalian lip and primary palate form when coordinated growth and morphogenesis bring the nasal and maxillary processes into contact, and the epithelia co-mingle, remodel and clear from the fusion site to allow mesenchyme continuity. Although several genes required for fusion have been identified, an integrated molecular and cellular description of the overall process is lacking. Here, we employ single cell RNA sequencing of the developing mouse face to identify ectodermal, mesenchymal and endothelial populations associated with patterning and fusion of the facial prominences. This analysis indicates that key cell populations at the fusion site exist within the periderm, basal epithelial cells and adjacent mesenchyme. We describe the expression profiles that make each population unique, and the signals that potentially integrate their behaviour. Overall, these data provide a comprehensive high-resolution description of the various cell populations participating in fusion of the lip and primary palate, as well as formation of the nasolacrimal groove, and they furnish a powerful resource for those investigating the molecular genetics of facial development and facial clefting that can be mined for crucial mechanistic information concerning this prevalent human birth defect.

Face morphogenesis is promoted by Pbx-dependent EMT via regulation of Snail1 during frontonasal prominence fusion.

Human cleft lip with or without cleft palate (CL/P) is a common craniofacial abnormality caused by impaired fusion of the facial prominences. We have previously reported that, in the mouse embryo, epithelial apoptosis mediates fusion at the seam where the prominences coalesce. Here, we show that apoptosis alone is not sufficient to remove the epithelial layers. We observed morphological changes in the seam epithelia, intermingling of cells of epithelial descent into the mesenchyme and molecular signatures of epithelial-mesenchymal transition (EMT). Utilizing mouse lines with cephalic epithelium-specific Pbx loss exhibiting CL/P, we demonstrate that these cellular behaviors are Pbx dependent, as is the transcriptional regulation of the EMT driver Snail1. Furthermore, in the embryo, the majority of epithelial cells expressing high levels of Snail1 do not undergo apoptosis. Pbx1 loss- and gain-of-function in a tractable epithelial culture system revealed that Pbx1 is both necessary and sufficient for EMT induction. This study establishes that Pbx-dependent EMT programs mediate murine upper lip/primary palate morphogenesis and fusion via regulation of Snail1. Of note, the EMT signatures observed in the embryo are mirrored in the epithelial culture system.

Three-dimensional printed haptic model from a prenatal surface-rendered oropalatal sonographic view: a new tool in the surgical planning of cleft lip/palate.

Three-dimensional (3D) ultrasound has significantly improved prenatal screening and perinatal care in the area of cleft lip/palate and other deformities, providing essential preoperative information to the surgical team. However, current 3D reconstruction modalities are limited primarily to display on a two-dimensional surface. In contrast, a 3D printed haptic model allows both the surgeon and the parents to develop a better understanding of the anatomy and the surgical procedure through the ability to interact directly with the printed model. The production of a 3D printed haptic model of cleft lip and palate obtained from a surface-rendered oropalatal sonographic view is presented here. The development of this 3D printed haptic model will allow the surgical team to perform preoperative planning with a highly accurate medical model, and it therefore represents a new tool in the management of cleft lip/palate. It also provides better prenatal information for the parents.

Pathogenesis of Cleft Palate in Robin Sequence: Observations From Prenatal Magnetic Resonance Imaging.

PURPOSE: The etiology of the palatal cleft in Robin sequence (RS) is unknown. The purpose of this study was to assess the position of the fetal tongue at prenatal magnetic resonance imaging (MRI) and to suggest a potential relation between tongue position and development of the cleft palate seen in most patients with RS. MATERIALS AND METHODS: This is a retrospective case-and-control study including fetuses with prenatal MRIs performed in the authors' center from 2002 to 2017. Inclusion criteria were 1) prenatal MRI of adequate quality, 2) liveborn infant, and 3) postnatal diagnosis of RS (Robin group) or cleft lip and palate (CLP group). Patients with postnatal RS without a palatal cleft were excluded. A control group with normal facial morphology was matched by gestational age. The outcome variable was tongue position at fetal MRI, described as within the cleft, along the floor of the mouth (normal), other, or indeterminate. RESULTS: One hundred twenty-two patients with mean gestational age at MRI of 25.8 ± 4.9 weeks were included (Robin, n = 21 [17%]; CLP, n = 47 [39%]; control, n = 54 [44%]). The tongue was visualized within the palatal cleft in 76.2% of the Robin group and 4.3% of the CLP group. The tongue was found along the floor of the mouth (normal) in the remainder of the Robin and CLP groups and in 100% of the control group. CONCLUSION: These findings suggest a relation between in utero tongue position and the development of cleft palate in RS.

Assessing the association between hypoxia during craniofacial development and oral clefts

Abstract Objectives To evaluate the association between hypoxia during embryo development and oral clefts in an animal model, and to evaluate the association between polymorphisms in the HIF-1A gene with oral clefts in human families. Material and Methods The study with the animal model used zebrafish embryos at 8 hours post-fertilization submitted to 30% and 50% hypoxia for 24 hours. At 5 days post-fertilization, the larvae were fixed. The cartilage structures were stained to evaluate craniofacial phenotypes. The family-based association study included 148 Brazilian nuclear families with oral clefts. The association between the genetic polymorphisms rs2301113 and rs2057482 in HIF-1A with oral clefts was tested. We used real time PCR genotyping approach. ANOVA with Tukey's post-test was used to compare means. The transmission/disequilibrium test was used to analyze the distortion of the inheritance of alleles from parents to their affected offspring. Results For the hypoxic animal model, the anterior portion of the ethmoid plate presented a gap in the anterior edge, forming a cleft. The hypoxia level was associated with the severity of the phenotype (p<0.0001). For the families, there was no under-transmitted allele among the affected progeny (p>0.05). Conclusion Hypoxia is involved in the oral cleft etiology, however, polymorphisms in HIF-1A are not associated with oral clefts in humans.

Oral vitamin B1-substitution does not decrease genetically determined cleft rate in mice (A/WySn).

PURPOSE: Cleft lip and palate (CL/P) are one of the most common human birth defects. Animal experiments and clinical investigations show a clear reduction of teratogenic clefts by a high-dose vitamin B supplementation during early pregnancy, especially in families at risk (reduction of recurrence). The aim of this work was to examine the influence of thiamine (vitamin B1) on CL/P appearance in genetically determined A/WySn mice within different supplementation starting points. MATERIALS AND METHODS: A total of 24 A/WySn female mice were orally supplemented with high doses (80 mg/kg) of thiamine at different times of pregnancy (5 groups, n = 90). The influence of thiamine on the abortion rate and CL/P appearance in the offspring was analyzed with respect to the concentration of thiamine in the serum and amniotic fluid (HPLC-chromatography). Immunochemical analyses of the ThTr-1 und ThTr-2 receptor-status were performed in midface sections of A/WySn-fetuses and the corresponding placenta, with and without CL/P. RESULTS: High doses of orally supplemented thiamine did not reduce the CL/P appearance in A/WySn mice. However, the different starting points of vitamin B1 substitution had some influence. Additionally, an obvious decrease in aborted fetuses was noticed in all supplemented groups. The oral substitution caused a clear increase of the serum concentration in all mothers, but showed no increase of the amniotic fluid concentration. Then immunohistochemistry detected an overexpression of ThTr-1 in the midface and an irregular localization of ThTr-2 in the placenta of fetuses with clefts. CONCLUSION: Our results suggest a time-dependent influence of thiamine on CL/P appearance in female mice. The prophylactic/periconceptional, but not the therapeutic supplementation, starting point can be proposed as a crucial step for regular facial and palatal fusion in embryonic development. The absolute rate of CL/P was not reduced, and the concentration of the water-soluble thiamine could not increase in the amniotic fluid. Thus the proposed local effect of thiamine failed in the development of genetically determined mice.

IRF6 and SPRY4 Signaling Interact in Periderm Development.

Rare mutations in IRF6 and GRHL3 cause Van der Woude syndrome, an autosomal dominant orofacial clefting disorder. Common variants in IRF6 and GRHL3 also contribute risk for isolated orofacial clefting. Similarly, variants within genes that encode receptor tyrosine kinase (RTK) signaling components, including members of the FGF pathway, EPHA3 and SPRY2, also contribute risk for isolated orofacial clefting. In the mouse, loss of Irf6 or perturbation of Fgf signaling leads to abnormal oral epithelial adhesions and cleft palate. Oral adhesions can result from a disruption of periderm formation. Here, we find that IRF6 and SPRY4 signaling interact in periderm function. We crossed Irf6 heterozygous ( Irf6+/-) mice with transgenic mice that express Spry4 in the basal epithelial layer ( TgKRT14::Spry4). While embryos with either of these mutations can have abnormal oral adhesions, using a new quantitative assay, we observed a nonadditive effect of abnormal oral epithelial adhesions in the most severely affected double mutant embryos ( Irf6+/-;TgKRT14::Spry4). At the molecular level, the sites of abnormal oral adhesions maintained periderm-like cells that express keratin 6, but we observed abnormal expression of GRHL3. Together, these data suggest that Irf6 and RTK signaling interact in regulating periderm differentiation and function, as well as provide a rationale to screen for epistatic interactions between variants in IRF6 and RTK signaling pathway genes in human orofacial clefting populations.

Toward Microsurgical Correction of Cleft Lip Ex Utero through Restoration of Craniofacial Developmental Programs.

BACKGROUND: Cleft lip with or without cleft palate is present in approximately one in 500 to 700 live births, representing the most common congenital craniofacial anomaly. Previously, the authors developed a unique murine model with compound Pbx deficiency that exhibits fully penetrant cleft lip with or without cleft palate. To investigate the possibility of tissue repair at an early gestational stage, the authors designed a minimally invasive surgical approach suitable for intrauterine repair using Wnt9b-soaked collagen microspheres to restore craniofacial developmental programs for cleft correction. METHODS: Collagen microspheres with diameters ranging from 20 to 50 µm were fabricated to serve as a delivery vehicle for Wnt9b. At gestational day 11.5, wild-type and Pbx-deficient murine embryos were isolated. Microspheres soaked in murine purified Wnt9b protein were microsurgically implanted at the midface lambdoidal junction. Embryos were cultured in a 37°C modified whole-embryo culture system. RESULTS: Targeted release of Wnt9b resulted in augmented Wnt expression at the lambdoidal junction. Microsurgical implantation of Wnt9b-soaked microspheres resulted in cleft correction in 27.1 percent of the Pbx-deficient embryos. The difference in the ratio of the areas of clefting between implanted and nonimplanted embryos was significant (p < 0.05). CONCLUSIONS: Ex utero correction of cleft lip with or without cleft palate in the authors' murine model by means of microsurgical intervention and targeted delivery of Wnt proteins is an innovative and promising strategy. Although further refinement and optimization of this technique will be required to improve efficacy, the authors believe that this approach will open new avenues toward unconventional prenatal interventions for patients with cleft lip with or without cleft palate, and provide future approaches for prenatal repair of other congenital head and neck disorders.

[Correlation between antenatal ultrasound and postnatal diagnosis in cleft lip or palate: A retrospective study of 44 cases]. / Corrélation anté- et postnatale dans le cadre de fentes du palais primaires ou secondaires : étude rétrospective de 44 cas.

OBJECTIVES: Anomalies of the maxillofacial development concern 1 for 700 births. About 30% of prenatal diagnoses of isolated primary cleft palate or associated with a cleft of secondary palate will be corrected in postnatal. This retrospective observational study was designed to compare the antenatal data and postnatal diagnosis regarding a series of clefts. MATERIALS AND METHODS: All children born between 1 December 2009 and 31 January 2014 in a prenatal diagnostic reference center and having a cleft palate were included. Newborns with an abnormality associated with the cleft were excluded. A comparison was made between the data in the antenatal ultrasound reports and postnatal those described by the surgeon during surgery. RESULTS: Forty-four children were included and three infants were excluded due to associated anomalies. Of those 41 children, 27 children have been screened. Ultrasound and clinical diagnosis was the same for 23 cases (85.2%) and inaccurate for 4 patients (14.8%). In case of primary cleft palate prenatal diagnosis was performed to 19 cases of 21 (90.5%), but only 8 of 20 if only secondary cleft palate (42.1%) including 7 with a Pierre-Robin sequence. DISCUSSION: Antenatal screening sensitivity of primary and secondary cleft palate increase in recent years with a rate of 85.2% in our series. By contrast, diagnosis of isolated secondary cleft palate seems to be more difficult and 3D ultrasound does not always improve screening performance. CONCLUSION: Ultrasound 2D seem sufficient for screening of primary and secondary cleft palate. The 3D ultrasound may be useful for a better representation of the cleft for future parents. The same language concerning the classification of the clefts facilitates harmonization of reporting and understanding between professionals. The presence of the maxillofacial surgeon ultrasound room would allow the sonographer to direct its ultrasound accurately or improve its learning curve.

Radiology of Cleft Lip and Palate: Imaging for the Prenatal Period and throughout Life.

Recent advances in prenatal imaging have made possible the in utero diagnosis of cleft lip and palate and associated deformities. Postnatal diagnosis of cleft lip is made clinically, but imaging still plays a role in detection of associated abnormalities, surgical treatment planning, and screening for or surveillance of secondary deformities. This article describes the clinical entities of cleft lip with or without cleft palate (CLP) and isolated cleft palate and documents their prenatal and postnatal appearances at radiography, ultrasonography (US), magnetic resonance (MR) imaging, and computed tomography (CT). Imaging protocols and findings for prenatal screening, detection of associated anomalies, and evaluation of secondary deformities throughout life are described and illustrated. CLP and isolated cleft palate are distinct entities with shared radiologic appearances. Prenatal US and MR imaging can depict clefting of the lip or palate and associated anomalies. While two- and three-dimensional US often can depict cleft lip, visualization of cleft palate is more difficult, and repeat US or fetal MR imaging should be performed if cleft palate is suspected. Postnatal imaging can assist in identifying associated abnormalities and dentofacial deformities. Dentofacial sequelae of cleft lip and palate include missing and supernumerary teeth, oronasal fistulas, velopharyngeal insufficiency, hearing loss, maxillary growth restriction, and airway abnormalities. Secondary deformities can often be found incidentally at imaging performed for other purposes, but detection is necessary because they may have considerable implications for the patient.

Evidence-based medicine: Unilateral cleft lip and nose repair.

LEARNING OBJECTIVES: After reading this article, the participant should be able to: 1. Describe the anatomical malformations found in unilateral cleft lip deformity. 2. Discuss current methods of measuring the deformity and subsequent outcomes. 3. Discuss preoperative assessments, workup, and the use of early interventions before definitive cheiloplasty (e.g., preoperative orthopedics, lip adhesion). 4. Discuss the different techniques used for cheiloplasty and nasal repair. 5. Discuss the use of postoperative splints, taping, or molding. 6. Discuss the outcomes and evidence of cleft lip repairs and identify areas for future research. SUMMARY: The Maintenance of Certification module series is designed to help clinicians structure their individualized course of study to specific areas appropriate to their clinical practice. This article was prepared to accompany practice-based assessment of preoperative evaluation, anesthesia, surgical treatment plan, perioperative management, and outcomes. In this format, the clinician is invited to compare his or her methods of patient assessment and treatment, outcomes, and complications, with authoritative, information-based references. This information base is then used for self-assessment and benchmarking in parts II and IV of the Maintenance of Certification process of the American Board of Plastic Surgery. This article is not intended to be an exhaustive treatise on the subject. Rather, it is designed to serve as a reference point for further in-depth study by review of the reference articles presented.

Anatomy research of nasolabial muscle structure in fetus with cleft lip: an iodine staining technique based on microcomputed tomography.

A thorough knowledge of the anatomic structure of the orbicularis oris of the upper lip and the nasalis in fetus with cleft lip is the key for the success of cleft lip repair. To understand the anatomic structure of the muscles of nasolabial region in fetus with cleft lip, the nasolabial tissues in 4 aborted fetuses with cleft lip were soaked for 7 days with iodine solution (Lugol solution of 3.75%) and were given micro-computed tomography. After the iodine solution permeated into the soft tissues, a good contrast was showed between muscle fibers and other fibrillar connective tissues. Through the observation of the obtained images, we found that most orbicularis oris fibers gathered into bundles with clear outline and only had slight deformation and displacement on the health side of the cleft of the unilateral incomplete cleft lip; however, in the lateral cleft, the muscle fibers not only had deformation and displacement but also were immature, disorganized, and not gathered into bundles. After being restored in Digital Imaging and Communications in Medicine format, the obtained images were then transferred into Materialise's interactive medical image control system, edited, and reconstructed into three-dimensional models. The models clearly showed the spatial relationship between the muscular tissues of the nasolabial region and the nasolabial outline in fetus with cleft lip.

Unilateral cleft lip repair.

Modern cleft surgery requires four-dimensional and functional anatomic understanding of the cleft (and noncleft) lip, nose, and alveolus. Some techniques for nasolabial repair rely more on precise anatomic geometry, whereas others afford the surgeon a more flexible design. Consistent anthropometry enables accurate assessment and reporting of long-term outcomes; such reports are needed to guide perioperative care, delineate optimal repair principles, and resolve ongoing controversies.

Facial cleft detected: is the palate normal?

Despite advances in ultrasound technology, the sensitivity for detection of facial clefts at the routine mid-trimester details scan remains relatively poor. This can be improved by the use of a three-point ultrasound screening protocol, although this is not routine in many countries. When a facial cleft is suspected at the routine scan, further imaging is usually required to detail the extent of the cleft and presence or absence of any other abnormalities. Involvement of the fetal palate is an important finding that will determine the requirement for surgery, audiology, and orthodontic services well into teenage years. There remains little uniformity in how a facial cleft is described antenatally, with involvement of the alveolar ridge frequently and incorrectly taken to mean involvement of the palate. Further, midline clefts of the hard and soft palates, where the fetal lips and alveolar ridge are intact, are a feature of many genetic conditions, but are almost never diagnosed by prenatal ultrasound. In this chapter, we detail issues surrounding the nomenclature of facial clefts in relation to the palate, and describe some of the more commonly used two-dimensional and three-dimensional methodologies for imaging the fetal palate.

Facial clefts and facial dysplasia: revisiting the classification.

Most craniofacial malformations are identified by their appearance. The majority of the classification systems are mainly clinical or anatomical, not related to the different levels of development of the malformation, and underlying pathology is usually not taken into consideration. In 1976, Tessier first emphasized the relationship between soft tissues and the underlying bone stating that "a fissure of the soft tissue corresponds, as a general rule, with a cleft of the bony structure". He introduced a cleft numbering system around the orbit from 0 to 14 depending on its relationship to the zero line (ie, the vertical midline cleft of the face). The classification, easy to understand, became widely accepted because the recording of the malformations was simple and communication between observers facilitated. It represented a great breakthrough in identifying craniofacial malformations, named clefts by him. In the present paper, the embryological-based classification of craniofacial malformations, proposed in 1983 and in 1990 by us, has been revisited. Its aim was to clarify some unanswered questions regarding apparently atypical or bizarre anomalies and to establish as much as possible the moment when this event occurred. In our opinion, this classification system may well integrate the one proposed by Tessier and tries at the same time to find a correlation between clinical observation and morphogenesis.Terminology is important. The overused term cleft should be reserved to true clefts only, developed from disturbances in the union of the embryonic facial processes, between the lateronasal and maxillary process (or oro-naso-ocular cleft); between the medionasal and maxillary process (or cleft of the lip); between the maxillary processes (or cleft of the palate); and between the maxillary and mandibular process (or macrostomia).For the other types of defects, derived from alteration of bone production centers, the word dysplasia should be used instead. Facial dysplasias have been ranged in a helix form and named after the site of the developmental arrest. Thus, an internasal, nasal, nasomaxillary, maxillary and malar dysplasia, depending on the involved area, have been identified.The classification may provide a useful guide in better understanding the morphogenesis of rare craniofacial malformations.

Lower concentrations of B-vitamin subgroups in the serum and amniotic fluid correlate to cleft lip and palate appearance in the offspring of A/WySn mice.

PURPOSE: The pathogenesis and prevention of cleft lip and palate (CL/P) have been studied mainly in clinical and animal experiments. A prophylactic poly-B-vitamin substitution during the first months of pregnancy has provided the most encouraging results for the prevention of CL/P recurrence in families at risk. In vitro studies of the palatal organ in an A/WySn mouse model have confirmed the positive influence of B-vitamins on palatal development. The present animal study was performed to analyze different B-vitamin concentrations in the serum and amniotic fluid of A/WySn mice according to the appearance of CL/P in their offspring. MATERIAL AND METHODS: Concentrations of different B-vitamins (B1, B2, B3, B5, B6, and folic acid) in serum and amniotic fluid were analyzed by high-performance liquid chromatographic detection. Immunohistochemical staining against thiamin-1 receptor was performed on histologic midface sections of A/WySn fetuses with (n = 12) and without (n = 14) CL/P. RESULTS: Vitamin B5 (P < .001) and folic acid (P < .004) concentrations in the amniotic fluid of dams with CL/P were significantly lower than in dams without CL/P. Serum concentrations of folic acid (P = .5) and B5 (P = .4) showed no difference between the 2 groups. Dams with CL/P had significantly lower thiamine concentrations in serum (P = .01) and amniotic fluid (P < .001). Histologic midface sections presented high thiamin-1 receptor expression in the palatal shelf of fetuses with CL/P. CONCLUSION: A decreased use or uptake of some B-vitamin subgroups (B1, B5, and folic acid) in amniotic fluid and serum (vitamin B1) was correlated to an increased cleft appearance in A/WySn mice. The high thiamin-1 receptor expression in the palatal tissue of mouse fetuses with CL/P may be caused by a decreased availability of vitamin B1.

Bases ambientales y genéticas de las fisuras orofaciales: revisión / Narrative review: environmental and genetic basis of orofacial clefts

El desarrollo embriológico de las estructuras orofaciales es un proceso complejo guiado por programas genéticos. Alteraciones en esos procesos dan lugar a anomalías estructurales. Un ejemplo de ellas son las fisuras de labio y el paladar. Las principales vías involucradas en las fisuras tienen como participantes a las familias del factor de crecimiento fibroblástico (FGF), Hedgehog (HH), Wingless (WNT) y la familia del factor de crecimiento transformante beta (TGFß), que incluye las proteínas morfogenéticas del hueso (BMPs) y activinas. En esta revisión narrativa se presentan algunos de los procesos celulares, moleculares y factores ambientales implicados en el desarrollo del complejo orofacial, finalizando con posibilidades terapéuticas para la evidencia acumulada.

Complex genetic process guides the embryonic head development. Alterations in these processes result instructural abnormalities. An example of these are the cleft lip and palate. The major pathways involved in the fissures are families: the Fibroblast Growth Factor (FGF) family, the Hedgehog (HH) family, the Wingless (WNT) family and the Transforming Growth Factor beta (TGF-ß) family, which includes the Bone Morphogenetic Proteins (BMPs) and Activins. In this review, we discuss some of the celular/molecular processes and environmental factors involved in the development of the orofacial complex, ending with therapeutic possibilities and potential clinical relevance to the accumulated evidence.