Gene and protein expressions of vimentin and desmin during embryonic development of the mylohyoid muscle.

Meckel's cartilage is known to be involved in formation of the prenatal mandible. However, the relationship between Meckel's cartilage and the embryonic mylohyoid muscle during growth and development has been investigated only rarely. This study examined the expression of intermediate filaments in Meckel's cartilage and the embryonic mylohyoid muscle in fetal mice during morphological development. Specimens of E12-16 ICR mice sectioned in the frontal direction were subjected to immunohistochemistry for vimentin and desmin. Hematoxylin and eosin sections showed that the immature mylohyoid muscle began to grow along Meckel's cartilage during fetal development. Weak vimentin expression was detected in the mylohyoid muscle and surrounding tissues at E12. Desmin expression was detected specifically in the mylohyoid, and strong expression was evident after E13, and increased with age. It was inferred that the mylohyoid muscle is one the tissues developing from Meckel's cartilage, the latter exerting a continuous influence on the growth of the former. In the early stage, the surrounding mesenchymal tissues expressing vimentin formed a scaffold for the developing mylohyoid muscle. Muscle attachment at E13 showed steady desmin expression, which continued until maturity. This study suggested the possibility that Meckel's cartilage has an influence not only on the mandibular bone, but also on the development of the mylohyoid muscle attached to the mandibular bone. Furthermore, it revealed a stage of the developmental process of the mylohyoid muscle in which the expression of vimentin, which is a common protein in the surrounding tissue such as muscle and bone, induces the morphological formation of the mylohyoid muscle, cooperating with the surrounding structures.

Anatomy and growth of the fetal soft palate: a cadaveric study to improve its ultrasonographic observation.

OBJECTIVE: To determine the anatomy of the soft and hard palate during fetal growth in order to improve its ultrasonographic prenatal visualization. DESIGN: Anatomic study in human formalin-fixed fetus. METHODS: The heads of 18 second and third trimester fetuses were studied in the median sagittal plan. Measurements of the soft palate, the velopharynx, the root of the tongue, and the oral floor were taken. The hard palate/soft palate angle and the anterior cranial base/soft palate angle were measured. RESULTS: The growth of the hard palate was linear, and the growth of the soft palate was polynomial (second order) during the period studied. The hard palate/soft palate angle was 150.33 degrees +/- 7.62 and 150.20 degrees +/- 6.67 in the second and third trimester, respectively. The anterior position of the soft palate in relation to the anterior cranial base was 48.8 degrees +/- 3.13 in the second trimester and 52.26 degrees +/- 3.31 in the third trimester. Its posterior position was 89.66 degrees +/- 5.51 in the second trimester and 92.97 degrees +/- 4.01 in the third trimester. Throughout the fetal period, the soft palate moved downward relative to the clivus and cervical spine. CONCLUSIONS: Despite the nonlinear growth and downward displacement of the soft palate during fetal life, its position remains stable. These results may be useful to explore the fetal soft palate using 2D and 3D ultrasonography and to improve the prenatal diagnosis of isolated cleft palate.

A case of primitive floor of the mouth paraganglioma in a child: an embryological theory unifying viscerocranium appended paragangliomas.

BACKGROUND: Paragangliomas are unusual tumors in the head and neck originating from the paraganglia or glomus cells of neural crest origin. METHODS: We describe the first case of a primitive paraganglioma of the floor of the mouth presenting in childhood. RESULTS: Complete surgical removal was performed after embolization of the left lingual artery. There was no evidence of either persistent or recurrent disease 5 years after surgery. The embryologic and anatomic origins of head and neck paragangliomas are reviewed. CONCLUSIONS: An embryologic theory based on the common neural crest origin and migration pathways of both autonomic viscerocranium appended ganglias and paragangliomas is proposed that unifies the topographically heterogeneous group of viscerocranium-appended paragangliomas.

Bone morphogenetic protein-2 and -4 expression during murine orofacial development.

In the developing orofacial region, epithelial-mesenchymal interactions induce a differentiation cascade leading to bone and cartilage formation. Although the nature of this interaction is unknown, bone morphogenetic proteins (BMP)-2 and -4 have been suggested as putative signalling molecules. Using 35S-labelled cDNA probes, the expression patterns of BMP-2 and -4 mRNA were examined in murine perioral tissues preceding, during and following the time of the epithelial-mesenchymal interaction leading to mandibular formation. At embryonic age (e) 9.5 days, a restricted pattern of BMP-4 mRNA was expressed in the epithelium of the developing facial processes. This decreased rapidly, with little or no signal on E10.5 or E11.5. By E13.5, BMP-4 signal was restricted to the dental lamina, follicle and papilla. BMP-2 expression was not prominent in the developing face until E13.5. At this stage, signal was widespread throughout mesenchyme of neural-crest, but not somatic origin. Different domains of expression were present in the developing epithelium: for example, there was strong signal in the floor of the mouth and the ventral tongue, in contrast to that of the dorsum of the tongue and primary palate, which were negative. These results support the role of BMP-2 and -4 as regulators of orofacial development and demonstrates different fields of BMP-2 expression in developing oral mucosal epithelium.

Histological evidence of fusion between the posterior palatal shelves and the floor of the mouth in Alligator mississippiensis.

Unlike the anterior four-fifths of the secondary palatal shelves the posterior one-fifth grows vertically downward along the side of the tongue and unites with the floor of the mouth. This feature appears to be unique to alligators, and may be important in the development of the basihyal valve. The valve seals off the mouth from the nasal cavities, pharynx and larynx, and thus allows simultaneous breathing and capturing of prey while in the aquatic environment. This developmental feature may enhance the survival value of the species.

EXTENCION SUBLINGUAL CON ACRILICO DE AUTOPOLIMERIZACION PARA RETENCION DE DENTADURAS

Es una técnica que requiere una solo sesión - Esta al alcance de cualquier profesional, por ser de facil manipulación - El tiempo que se emplea es solamente de 20 a 30 minutos - Siguiendo los pasos de la técnica, se obtuvo retención esta factoria en los doce casos clínicos - No se desplaza con los movimientos musculares normales - El paciente, en ningún momento , queda desdentado salvo el tiempo que dura la intervención - Todo los pacientes toleran el material agrupado, sin que produsca ninguna molestia ni dolores posteriores - El paciente siente mejoramiento immediato y se dá cuenta que la dentadura está mucho más firme - La Técnica es simple, por lo tanto, no se requiere de instrumental especializado