RESUMO
OBJECTIVE: The aim: The paper was aimed at the study of the processes of mineralization of the enamel of the permanent tooth after its eruption. PATIENTS AND METHODS: Materials and methods: To study the structure of the enamel of permanent teeth has been carried out using light and electron microscopy. The study of the process of the development of the primordia of the permanent teeth involved 10 culled puppies of 30-40 days of age. Microscopic, electron microscopic, immunohistochemical methods of research have been used to study the processes of histogenesis. RESULTS: Results: The studies show that in the postnatal period, the formation of the crown, externally covered with cuticular epithelium, marks the formation of the primordium of the permanent tooth at the follicle stage. After eruption of a tooth, different parts of its crown have three individual structural and functional barriers to enamel biomineralization. The first one is provided by the cuticular epithelium of the pitted areas of the crown, which ensures filtering of the salivary fluid from the protein deposit in the form of a pellicle. The second barrier is defined on the lateral and cuspidate surfaces of the enamel, where the cuticle is erased or poorly expressed. The third structural and functional barrier of enamel biomineralization is located in the cervical portion of teeth of different classes. CONCLUSION: Conclusions: Different areas of the enamel in the tooth crown have specific filtration barriers, which can be distinguished as follows: pit-and-fissure-and-groove, cuspidateand-approximal, and cervical barriers. The cuticle is poorly expressed or totally absent on the cusps of the tooth crowns in contrast to pitted areas.
Assuntos
Erupção Dentária , Dente , Animais , Coroas , Esmalte Dentário , Cães , Microscopia EletrônicaRESUMO
OBJECTIVE: The aim: Thepaper wasaimedat thestudyof thebiomineralization processesofa permanentdental crown in thepostnatal period of histogenesis. PATIENTS AND METHODS: Materials and methods: The study involved 30 culled puppies aged 30-40 days. To study the histogenesis of the germs of the permanent tooth from the cuticular epithelium in the postnatal period microscopic, electron microscopic, immunohistochemical methods of study have been used. RESULTS: Results: The studies show that in the postnatal period, the maturation of the germ of a permanent tooth starts with the synthesis of cells of the cuticular epithelium of the organic stroma, capable of subsequent mineralization. Differentiation of the proameloblasts, located on the surface of the dental papillary mesenchyma, at the early stages of histogenesis, is strongly associated with the appearance of a specific protein taftelin. Origination of secretory ameloblasts, which produce the protein enamelin, triggers the process of secondary biomineralization of the enamel. The terminal processes of the secretory ameloblasts produce the protein in the form of layers that overlap each other at a certain angle. Such layering of the structures of enamel and dentin contributes to the S-shaped maturation of the hard tooth tissues, strengthening them considerably. At the follicle stage, maturation of the dental crown, coated with cuticular epithelium, occurs. Invaginations of the cuticular epithelium form a characteristic topography of the dental crown, and enamel projections are further formed by the ameloblasts. Epitheliocytes of the inner layer of the enamel organ have desmosomal connections that allow the filtration of the salivary fluid at the stage of the enamel trophism. CONCLUSION: Conclusions: The findings of the study suggest that, normally, due to the cuticular epithelium, filtration of the salivary fluid occurs with protein deposition on it and subsequent infiltration of the calcium salts into the subjacent enamel.
Assuntos
Biomineralização , Odontogênese , Adulto , Ameloblastos , Animais , Coroas , Cães , Células Epiteliais , HumanosRESUMO
OBJECTIVE: Introduction: Chronic inflammatory diseases of the mucous membranes of the nose, paranasal sinuses, and pharynx are the most common pathology of the upper airways. Pathological processes develop more often in the maxillary and ethmoidal sinuses than in the frontal ones; however, the clinical course of frontitis is more severe. Fundamental understanding of the specific structure of frontal sinuses is crucial in the awareness of the precursors of the onset and development of its pathology, the choice of methods of diagnostics and treatment. The aim: The paper was aimed at the analysis of the publications on current data related to the structure and functions of the human frontal sinus and its structural components. Materials and methods: The bibliosemantic method has been used during the study. Findings of the current research works on the study of the human frontal sinus have been analyzed. RESULTS: Review: The resulting analysis shows that despite the significant amount of research works devoted to the study of the structure and functions of the frontal sinus, the morphofunctional features of its mucosa and the state of local immune protection remained unknown for a long time. CONCLUSION: Conclusions: The resulting literature review showed that the study of the morphofunctional properties of the frontal sinus is relevant to date that is reflected in the number of research works, elucidating its topographoanatomical, histological, physiological and immunohistochemical features.