Tooth development
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Choroba Charcot-Marie-Tooth (neboli CMT) je nejobvyklejším typem hereditární motoricko - senzorické neuropatie (HMSN). Odhaduje se, že v ČR žije 2 až 4 tisíce pacientů s touto chorobou. Klinický obraz je charakterizován postupným zhoršováním hybnosti a citlivosti dolních končetin (později i horních) následkem postižení periferních nervů. Je typické, že onemocnění zvolna progreduje. Charakteristické je zejména postižení DK, kde se již zpočátku vyvíjí typická deformita nohy, pro toto onemocnění tolik příznačná (pes cavus - transverzoplanus). Dále na DK pozorujeme progradující svalovou slabost postihující nejprve svalstvo nohy, později svalstvo bérce ev. i kořenové svalstvo. U onemocnění rozlišujeme 7 vývojových stupňů, které jsou mimo jiné charakterizovány právě topikou a stupněm svalového postižení. Práce shrnuje základní diagnostické postupy a následně komplexní léčbu, jejíž podstatnou součástí je i rehabilitace a protetika.
Charcot-Marie-Tooth disease (CMT) is the most comon type of hereditary sensory motor neuropathy (HMSN). It is estimated that in the CR there are some 2 to 4 thousand patients with this disease. The clinical picture is characterized by gradual deterioration of the mobility and sensitivity of the lower extremities (tater also the upper ones) due to peripheral nerve affection. It is typical that the disease progresses slowly. In particular affection of the lower extremities is typical: at first a typical deformity of the foot develops, characteristic for the disease (pes cavus - tramsversoplanus). On the lower extremity we observe moreover progressing muscular weakness affectiog first the muscles of the foot, tater the leg muscles and possibly the radicular muscles. There are 7 developmental stages of the disease which are characterized among others by the topical features and degree of muscular affection. The presented work summarizes basic diagnostic procedures and subsequent comprehensive treatment where a substantial part is formed by rehabilitation and prosthetics.
Správný vývoj kořene a ukotvení zubu do kosti jsou důležité pro ustanovení dynamických funkcí tohoto komplexu. Znalosti získané studiem formování zubu, periodoncia a kosti jsou významné také v oblasti regenerativní stomatologie u technik využívajících autotransplantace či kmenové buňky v rámci tkáňového inženýrství. V tommto příspěvku jsou prezentovány nové poznatky získané studiem myších modelů a zároveň diskutovány možné extrapolace na lidskou dentici.
Proper root development and anchorage of the tooth in the bone are essential for dynamic functions of such complex. The knowledge about tooth-periodontium-bone formation becomes essential also for restorative dentistry using autotransplantation techniques or stem cell based tissue engineering. In this contribution, novel findings from the mouse model are presented and related implications for human dentition discussed.
- MeSH
- cementogeneze fyziologie MeSH
- dentinogenesis fyziologie MeSH
- mandibula anatomie a histologie embryologie růst a vývoj MeSH
- modely u zvířat * MeSH
- moláry anatomie a histologie embryologie růst a vývoj MeSH
- myši MeSH
- odontogeneze fyziologie MeSH
- zubní kořen * anatomie a histologie embryologie růst a vývoj MeSH
- Check Tag
- myši MeSH
- Publikační typ
- práce podpořená grantem MeSH
The Eda pathway ( Eda, Edar, Edaradd) plays an important role in tooth development, determining tooth number, crown shape, and enamel formation. Here we show that the Eda pathway also plays a key role in root development. Edar (the receptor) is expressed in Hertwig's epithelial root sheath (HERS) during root development, with mutant mice showing a high incidence of taurodontism: large pulp chambers lacking or showing delayed bifurcation or trifurcation of the roots. The mouse upper second molars in the Eda pathway mutants show the highest incidence of taurodontism, this enhanced susceptibility being matched in human patients with mutations in EDA-A1. These taurodont teeth form due to defects in the direction of extension of the HERS from the crown, associated with a more extensive area of proliferation of the neighboring root mesenchyme. In those teeth where the angle at which the HERS extends from the crown is very wide and therefore more vertical, the mutant HERSs fail to reach toward the center of the tooth in the normal furcation region, and taurodont teeth are created. The phenotype is variable, however, with milder changes in angle and proliferation leading to normal or delayed furcation. This is the first analysis of the role of Eda in the root, showing a direct role for this pathway during postnatal mouse development, and it suggests that changes in proliferation and angle of HERS may underlie taurodontism in a range of syndromes.
- MeSH
- abnormality zubů genetika MeSH
- dítě MeSH
- ektodysplasiny genetika MeSH
- fenotyp MeSH
- kavita zubní dřeně abnormality MeSH
- lidé MeSH
- mladiství MeSH
- moláry abnormality embryologie MeSH
- myši MeSH
- odontogeneze genetika MeSH
- rentgenová mikrotomografie MeSH
- signální transdukce MeSH
- zubní kořen abnormality embryologie MeSH
- zvířata MeSH
- Check Tag
- dítě MeSH
- lidé MeSH
- mladiství MeSH
- mužské pohlaví MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Tooth number is abnormal in about 20% of the human population. The most common defect is agenesis of the third molars, followed by loss of the lateral incisors and loss of the second premolars. Tooth loss appears as both a feature of multi-organ syndromes and as a non-syndromic isolated character. Apart from tooth number, abnormalities are also observed in tooth size, shape, and structure. Many of the genes that underlie dental defects have been identified, and several mouse models have been created to allow functional studies to understand, in greater detail, the role of particular genes in tooth development. The ability to manipulate the mouse embryo using explant culture and genome targeting provides a wealth of information that ultimately may pave the way for better diagnostics, treatment or even cures for human dental disorders. This review aims to summarize recent knowledge obtained in mouse models, which can be used to gain a better understanding of the molecular basis of human dental abnormalities.
- MeSH
- abnormality zubů embryologie genetika patologie MeSH
- anodoncie genetika MeSH
- dentin abnormality embryologie MeSH
- fenotyp MeSH
- financování organizované MeSH
- fosfoproteiny genetika MeSH
- kostní morfogenetické proteiny genetika MeSH
- kostní morfogenetický protein 4 MeSH
- lidé MeSH
- modely u zvířat MeSH
- myši MeSH
- odontogeneze genetika MeSH
- parodont abnormality MeSH
- zubní sklovina abnormality embryologie MeSH
- zuby přespočetné embryologie MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- přehledy MeSH
This paper describes tooth development in a basal squamate, Paroedura picta. Due to its reproductive strategy, mode of development and position within the reptiles, this gecko represents an excellent model organism for the study of reptile development. Here we document the dental pattern and development of non-functional (null generation) and functional generations of teeth during embryonic development. Tooth development is followed from initiation to cytodifferentiation and ankylosis, as the tooth germs develop from bud, through cap to bell stages. The fate of the single generation of non-functional (null generation) teeth is shown to be variable, with some teeth being expelled from the oral cavity, while others are incorporated into the functional bone and teeth, or are absorbed. Fate appears to depend on the initiation site within the oral cavity, with the first null generation teeth forming before formation of the dental lamina. We show evidence for a stratum intermedium layer in the enamel epithelium of functional teeth and show that the bicuspid shape of the teeth is created by asymmetrical deposition of enamel, and not by folding of the inner dental epithelium as observed in mammals.
- MeSH
- buněčná diferenciace MeSH
- ještěři embryologie MeSH
- modely u zvířat MeSH
- odontogeneze fyziologie MeSH
- zubní sklovina embryologie MeSH
- zuby embryologie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Mineralized tissues, such as bones or teeth, are essential structures of all vertebrates. They enable rapid movement, protection, and food processing, in addition to providing physiological functions. Although the development, regeneration, and pathogenesis of teeth and bones have been intensely studied, there is currently no tool to accurately follow the dynamics of growth and healing of these vital tissues in space and time. Here, we present the BEE-ST (Bones and tEEth Spatio-Temporal growth monitoring) approach, which allows precise quantification of development, regeneration, remodeling, and healing in any type of calcified tissue across different species. Using mouse teeth as model the turnover rate of continuously growing incisors was quantified, and role of hard/soft diet on molar root growth was shown. Furthermore, the dynamics of bones and teeth growth in lizards, frogs, birds, and zebrafish was uncovered. This approach represents an effective, highly reproducible, and versatile tool that opens up diverse possibilities in developmental biology, bone and tooth healing, tissue engineering, and disease modeling.
- MeSH
- dánio pruhované * MeSH
- kosti a kostní tkáň MeSH
- myši MeSH
- vývoj kostí MeSH
- zubní kořen MeSH
- zuby * fyziologie MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- MeSH
- aminokyseliny chemie MeSH
- krysa rodu rattus MeSH
- messenger RNA analýza MeSH
- molekulární biologie MeSH
- novorozená zvířata MeSH
- proteiny zubní skloviny fyziologie chemie MeSH
- zubní sklovina chemie růst a vývoj MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- zvířata MeSH
- Publikační typ
- srovnávací studie MeSH
Detailní znalosti o normálním vývoji zubů jsou nezbytným předpokladem pro porozumění zubním defektům na molekulární úrovni a pro jejich možnou terapii založenou na tkáňovém inženýrství. Tento článek má za cíl shrnout základní kroky odontogenetických kaskád. Především bude diskutována role Shh (sonic hedgehog), Wnts (wingless-type MMTV integration site family), Fgf (fibroblast growth factors) a Bmp (bone morphogenetic proteins) proteinových rodin v jednotlivých fázích vývoje od iniciace po tvorbu tvrdých tkání zubu.
Detailed information about normal tooth development is an essential prerequisite for understanding dental defects at molecular level and their possible tissue engineering based therapy. This review aims to briefly summarise keystones of odontogenic molecular networks. Particularly, involvement of Shh (sonic hedgehog), Wnts (wingless-type MMTV integration site family), Fgfs (fibroblast growth factors) and Bmps (bone morphogenetic proteins) families in different stages of normal tooth development from initiation to hard tissues formation is discussed.
The first mouse molar (M1) is the most common model for odontogenesis, with research particularly focused on prenatal development. However, the functional dentition forms postnatally, when the histogenesis and morphogenesis of the tooth is completed, the roots form and the tooth physically anchors into the jaw. In this work, M1 was studied from birth to eruption, assessing morphogenesis, proliferation and apoptosis, and correlating these with remodeling of the surrounding bony tissue. The M1 completed crown formation between postnatal (P) days 0-2, and the development of the tooth root was initiated at P4. From P2 until P12, cell proliferation in the dental epithelium reduced and shifted downward to the apical region of the forming root. In contrast, proliferation was maintained or increased in the mesenchymal cells of the dental follicle. At later stages, before tooth eruption (P20), cell proliferation suddenly ceased. This withdrawal from the cell cycle correlated with tooth mineralization and mesenchymal differentiation. Apoptosis was observed during all stages of M1 postnatal morphogenesis, playing a role in the removal of cells such as osteoblasts in the mandibular region and working together with osteoclasts to remodel the bone around the developing tooth. At more advanced developmental stages, apoptotic cells and bodies accumulated in the cell layers above the tooth cusps, in the path of eruption. Three-dimensional reconstruction of the developing postnatal tooth and bone indicates that the alveolar crypts form by resorption underneath the primordia, whereas the ridges form by active bone growth between the teeth and roots to form a functional complex.
- MeSH
- apoptóza fyziologie MeSH
- imunohistochemie MeSH
- moláry růst a vývoj MeSH
- myši MeSH
- odontogeneze MeSH
- osteoklasty metabolismus MeSH
- proliferace buněk MeSH
- proliferační antigen buněčného jádra metabolismus MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Restoration of decayed primary teeth is very important and significant not only for the maintenance of health and psychics of the child but also for the physiological development of permanent dentition. Esthetic materials were formulated for permanent teeth restoration, but they can also be used for the treatment of primary dentition, especially in minimally invasive techniques, atraumatic tooth restoration, and preventive interventions. Composite resins, glass ionomers, resin modified glass ionomers, and compomers are the materials of choice in the form of direct filling. Findings of individual authors on success of esthetic primary teeth restoration are, however, different and further well-founded clinical trials and experimental studies are necessary. Opinions on the decision-making process when choosing a restorative material are very similar and can be formulated in the following way: To receive reliable results with esthetic material restoration in primary dentition three conditions have to be present: isolation, cooperation, and time. Microscopic structure peculiarities of primary enamel and dentin and time until tooth exfoliation have to be taken into consideration too. One has to state, however, that the longevity of tooth-colored materials has not been found higher than that of amalgam. That is why dentists should consider the diagnosis, ease of material placement, oral hygiene, caries risk, esthetic demands, and financial aspects when choosing a restorative material for primary teeth.
- MeSH
- akrylové pryskyřice terapeutické užití MeSH
- dentinová adheziva terapeutické užití MeSH
- dítě MeSH
- estetika stomatologická MeSH
- financování organizované MeSH
- kompomery terapeutické užití MeSH
- lidé MeSH
- skloionomerní cementy terapeutické užití MeSH
- trvalá zubní náhrada metody MeSH
- zuby mléčné MeSH
- Check Tag
- dítě MeSH
- lidé MeSH
- Publikační typ
- přehledy MeSH
