Maternal folic acid supplementation reduces the severity of cleft palate in Tgf-ß3 null mutant mice.

BACKGROUND: Cleft palate (CP) constitutes the most frequently seen orofacial cleft and is often associated with low folate status. Folate plays an essential role in the human body as a major coenzyme in one-carbon metabolism, including DNA synthesis, repair, and methylation. Whether the administration of isolated folic acid (FA) supplements prevents the CP caused by genetic mutations is unknown, as is its effect on the mechanisms leading to palate fusion. METHODS: FA was administered to females from two different strains of transforming growth factor ß3 heterozygous mice. Null mutant progeny of these mice exhibit CP in 100% of cases of varying severity. We measured cleft length, height of palatal shelf adhesion, and the number of proliferating mesenchymal cells. Immunohistochemistry was also carried for collagen IV, laminin, fibronectin, cytokeratin-17, and EGF. RESULTS: FA supplementation significantly reduced CP severity and improved palatal shelf adhesion in both strains both in vivo and in vitro. Medial edge epithelium proliferation increased, and its differentiation was normalized as indicated by the presence and disposition of collagen IV, laminin, fibronectin, and cytokeratin-17. CONCLUSIONS: A maternal FA supplementation reduces the CP appearance by improving the mechanisms leading to palatal shelf adhesion.

Epidermal growth factor impairs palatal shelf adhesion and fusion in the Tgf-ß 3 null mutant.

The cleft palate presented by transforming growth factor-ß3 (Tgf-ß3) null mutant mice is caused by altered palatal shelf adhesion, cell proliferation, epithelial-to-mesenchymal transformation and cell death. The expression of epidermal growth factor (EGF), transforming growth factor-ß1 (Tgf-ß1) and muscle segment homeobox-1 (Msx-1) is modified in the palates of these knockout mice, and the cell proliferation defect is caused by the change in EGF expression. In this study, we aimed to determine whether this change in EGF expression has any effect on the other mechanisms altered in Tgf-ß3 knockout mouse palates. We tested the effect of inhibiting EGF activity in vitro in the knockout palates via the addition of Tyrphostin AG 1478. We also investigated possible interactions between EGF, Tgf-ß1 and Msx-1 in Tgf-ß3 null mouse palate cultures. The results show that the inhibition of EGF activity in Tgf-ß3 null mouse palate cultures improves palatal shelf adhesion and fusion, with a particular effect on cell death, and restores the normal distribution pattern of Msx-1 in the palatal mesenchyme. Inhibition of TGF-ß1 does not affect either EGF or Msx-1 expression.

Injection and adhesion palatoplasty: a preliminary study in a canine model.

BACKGROUND: Raising mucoperiosteal flaps in traditional palatoplasty impairs mid-facial growth. Hyaluronic acid-based hydrogels have been successfully tested for minimally invasive craniofacial bone generation in vivo as carriers of bone morphogenetic protein-2 (BMP-2). We aimed to develop a novel flapless technique for cleft palate repair by injecting a BMP-2 containing hydrogel. MATERIAL AND METHODS: Dog pups with congenital cleft palate were either non-treated (n=4) or treated with two-flap palatoplasty (n=6) or with the proposed injection/adhesion technique (n=5). The experimental approach was to inject a hyaluronic acid-based hydrogel containing hydroxyapatite and BMP-2 subperiosteally at the cleft palate margins of pups aged six weeks. At week ten, a thin strip of the medial edge mucosa was removed and the margins were closed directly. Occlusal photographs and computed tomography (CT) scans were obtained up to week 20. RESULTS: Four weeks after the gel injection the cleft palate margins had reached the midline and engineered bone had enlarged the palatal bones. Removal of the medial edge mucosa and suturing allowed complete closure of the cleft. Compared to traditional palatoplasty, the injection/adhesion technique was easier, and the post-surgical recovery was faster. CT on week 20 revealed some overlapping or "bending" of palatal shelves in the two-flap repair group, which was not observed in the experimental nor control groups. CONCLUSION: A minimally invasive technique for cleft palate repair upon injectable scaffolds in a dog model of congenital cleft palate is feasible. Results suggest better growth of palatal bones. This represents an attractive clinical alternative to traditional palatoplasty for cleft palate patients.

Study of the functional relationships between the buccinator muscle and the connective tissue of the cheek in humans.

BACKGROUND: The buccinator muscle derives from the mesenchyme of the second pharyngeal arch. In adults, it has a quadrilateral shape, occupying the deepest part of the cheek region. Its function is complex, being active during swallowing, chewing, and sucking. To our knowledge, there are no studies that have specifically analyzed the relationship of the buccinator muscle fibers and neighboring connective tissue of the cheek in humans, neither during development nor in adults. Such relationships are fundamental to understand its function. Thus, in this study the relations of the buccinator muscle with associated connective tissue were investigated. METHODS: The buccinator muscle region was investigated bilaterally in 41 human specimens of 8-17 weeks of development. Moreover, four complete adult tissue blocks from human cadavers (including mucosa and skin) were obtained from the cheek region (between the anterior border of the masseter muscle and the nasolabial fold). All samples were processed with standard histological techniques. In addition, subsets of sections were stained with picrosirius red (PSR). Furthermore, immunoreactivity against type I and III collagen was also studied in adult tissues. RESULTS: The buccinator muscle showed direct relationships with its connective tissue from 8 to 17 weeks of development. Collagen fibers were arranged in septa from the submucosa to the skin through the muscle. These septa were positive for type I collagen and presented elastic fibers. Fibrous septa that were positive for type III collagen were arranged from the lateral side of the muscle to the skin. CONCLUSIONS: The intimate relationship between buccinator muscle fibers and cheek connective tissue may explain the complex functions of this muscle.

Investigación en fisuras faciales: quo vadis España? / Investigation in facial fissures: quo vadis Spain?

Las fisuras orofaciales representan un grupo heterogéneo de malformaciones congénitas que afectan a distintas estructuras de la cavidad oral y de la cara. Globalmente, los bebés con estos trastornos presentan una mayor morbilidad y mortalidad a lo largo de su vida en comparación con individuos no afectados. Por ello, los avances en la investigación biomédica resultan ineludibles. Así, el objetivo general de este trabajo fue llevar a cabo una revisión bibliográfica para analizar narrativamente los 10 principales estudios primarios sobre fisuras orofaciales llevados a cabo en España, publicados del 2018 hasta la actualidad. Según esto, a nivel institucional, destaca la Universidad Complutense de Madrid (UCM) con cuatro artículos publicados por el grupo de investigación UCM 920202. También sobresale la Universidad Rey Juan Carlos de Madrid, con tres artículos relacionados con diferentes aspectos de la personalidad y la calidad de vida de los pacientes fisurados, así como otras muchas variables cognitivo-emocionales. En relación con la Universidad de Valencia, encontramos dos artículos llevados a cabo en amplias muestras de pacientes con fisuras. Por último, en Barcelona resulta destacable un estudio observacional sobre problemas otorrinolaringológicos en pacientes operados de fisura palatina. En conclusión, si bien en los últimos años se han publicado varios artículos sobre distintos aspectos relacionados con las fisuras, aún queda mucho trabajo por hacer. España debería seguir potenciando proyectos con líneas de trabajo centradas en estas alteraciones del desarrollo craneofacial. Se necesitan estudios amplios, multicéntricos y colaborativos, para ahondar en los mecanismos etiológicos y, en última instancia, en las posibles herramientas para su prevención. Del mismo modo, se necesitan ayudas para dilucidar mejor las cuestiones relacionadas con los tratamientos en todas las dimensiones de la salud, preferentemente a partir de ensayos clínicos controlados aleatorizados, que faciliten la traslación de conocimientos y su accesibilidad universal dentro del sistema sanitario público español.

SUMMARY: Orofacial clefts represent a heterogeneous group of congenital malformations affecting different structures of the oral cavity and face. Overall, infants with these disorders have a higher lifetime morbidity and mortality compared to unaffected individuals. Therefore, advances in biomedical research are unavoidable. Thus, the overall objective of this work was to conduct a literature review to narratively analyse the 10 main primary studies on orofacial clefts carried out in Spain, published from 2018 to date. According to this review, at an institutional level, the Complutense University of Madrid (UCM) is notable with 4 articles published by the UCM 920202 research group. The Rey Juan Carlos University of Madrid also stands out, with three papers related to different aspects of the personality and quality of life of cleft patients, as well as many other cognitive-emotional variables. In relation to the University of Valencia, we found two studies carried out on large samples of cleft patients. Finally, in Barcelona, an observational study on otorhinolaryngological problems in cleft palate patients is noteworthy. In conclusion, although several studies have been published in recent years on different aspects related to clefts, there is still much work to be done. Spain should craniofacial development. Large, multicenter and collaborative studies are needed to delve deeper into the aetiological mechanisms and, ultimately, into the possible tools for their prevention. Similarly, support is needed to better elucidate questions related to treatments in all dimensions of health, preferably randomised controlled clinical trials, which facilitate the transfer of knowledge and its universal accessibility within the Spanish public health system.

Maxillary growth in a congenital cleft palate canine model for surgical research.

We have recently presented the Old Spanish Pointer dog, with a 15-20% spontaneous congenital cleft palate rate, as a unique experimental model of this disease. This study aimed to describe the cleft palate of these dogs for surgical research purposes and to determine whether congenital cleft palate influences maxillofacial growth. Seven newborn Old Spanish Pointer dogs of both sexes, comprising a cleft palate group (n = 4) and a normal palate group (n = 3), were fed using the same technique. Macroscopic photographs and plaster casts from the palate, lateral radiographs and computer tomograms of the skull were taken sequentially over 41 weeks, starting at week 5. The cleft morphology, the size and the tissue characteristics in these dogs resembled the human cleft better than current available animal models. During growth, the cleft width varies. Most of the transverse and longitudinal measures of the palate were statistically lower in the cleft palate group. The cleft palate group showed hypoplasia of the naso-maxillary complex. This model of congenital cleft palate seems suitable for surgical research purposes. A reduced maxillofacial pre- and post-natal development is associated to the congenital cleft palate in the Old Spanish Pointer dog.