Changes in catheptic activity in the enamel organ of the bovine tooth germ during development

1969 ◽  
Vol 14 (8) ◽  
pp. 987-990 ◽  
Author(s):  
S. Sakamoto ◽  
S. Sasaki
Keyword(s):  
Tooth Germ ◽  
Enamel Organ

Autoradiography of Incorporated Leucine-H3 in the Enamel Matrix and Enamel Organ of the Upper Incisor of the Rat

1964 ◽  
Vol 04 (02) ◽  
pp. 186-192
Author(s):  
Leonel Costacurta
Keyword(s):  
Amino Acid ◽  
Blood Vessels ◽  
Tooth Germ ◽  
Longitudinal Section ◽  
Equal Length ◽  
Enamel Organ ◽  
Enamel Matrix ◽  
Distal Extremity ◽  
Old Rats ◽  
Thin Band

SummaryDental germs of the upper incisors of six-days old rats were studied for the uptake of leucine-H3 by different layers of the enamel organ in correlation to the various stages of the development of enamel.The longitudinal section of the tooth germ was divided into 15 zones of about equal length in order to facilitate the description and interpretation of results. Autoradiographic images of the histologic preparations from rats sacrificed 30 minutes, 1 hour, 1 day and 3 days after the injection were made. The strongest reactions were observed in dental germs of rats sacrificed 1 hour, and particularly one day, after the leucine-H3 injection.The uptake of this compound by the enamel matrix increases progressively up to the young enamel and then decreases to the distal extremity; the greatest quantity of this labeled amino-acid was observed in the primary and young enamel. The reactions were present in the transitional enamel only along a thin band close to the dentine-enamel junction.In the enamel organ leucine-H3 incorporation was greatest in the three layers, the zones corresponding to primary and young enamel. In zones corresponding to transitional enamel, the inner epithelium showed a small quantity, and the stellate reticulum a blackening only in its superficial part, were the blood vessels reach the enamel organ.

Uptake of Radioactive Calcium by Hard Tissue Cells

1979 ◽  
Vol 58 (2_suppl) ◽  
pp. 1021-1022
Author(s):  
F.S. Sayegh ◽  
K. Porter ◽  
G. Sun
Keyword(s):  
Germ Cells ◽  
Calcium Uptake ◽  
Soluble Fraction ◽  
Specific Radioactivity ◽  
Tooth Germ ◽  
Enamel Organ ◽  
Hard Tissue ◽  
Subcellular Organelles ◽  
Tissue Cells ◽  
Tooth Germs

45Ca was injected into prenatal mice to study the calcium uptake by tooth germ cells. Both dental papillae, containing the odontoblasts, and the enamel organs were found to actively metabolize the labeled calcium. The maximum specific radioactivity occurred at 15 minutes after injection. The subcellular organelles (e.g. mitochondria) of the papillae were more active in metabolizing the labeled calcium whereas a large portion of the radioactivity of the enamel organ was found in a fraction containing the pre-calcified material. In fetal tooth germs, the rate of incorporation of labeled calcium into the pre-calcified material was slower than in the postnatal tooth germs since a large portion of the radioactivity remained in the soluble fraction.

Expression, localisation and synthesis of versican by the enamel organ of developing mouse molar tooth germ: An in vivo and in vitro study

2010 ◽  
Vol 55 (12) ◽  
pp. 995-1006 ◽  
Author(s):  
Bei-Zhan Jiang ◽  
Tamaki Yokohama-Tamaki ◽  
Zuo-lin Wang ◽  
Nobuko Obara ◽  
Shunichi Shibata
Keyword(s):  
In Vitro Study ◽  
Tooth Germ ◽  
Vitro Study ◽  
Molar Tooth ◽  
Enamel Organ

scholarly journals Papilliferous Keratoameloblastoma: An Extremely Rare Case Report

2013 ◽  
Vol 2013 ◽  
pp. 1-4 ◽  
Author(s):  
Neeta Mohanty ◽  
Varun Rastogi ◽  
Satya Ranjan Misra ◽  
Susant Mohanty
Keyword(s):  
English Literature ◽  
Tooth Germ ◽  
Enamel Organ ◽  
Oral Epithelium ◽  
Dental Lamina ◽  
Jaw Bones ◽  
Rare Case Report ◽  
Enamel Epithelium ◽  
Odontogenic Neoplasm ◽  
Maxilla And Mandible

Odontogenic tumors develop in the jaw bones from the odontogenic tissue-oral epithelium in tooth germ, enamel organ, dental papilla, reduced enamel epithelium, remnants of Hertwig’s root sheath or dental lamina, and so forth. Hence, a bewildering variety of tumors are encountered in the maxilla and mandible. Ameloblastoma is the second most common odontogenic neoplasm after odontomes, and it has numerous clinical and histologic variants. We report a very rare histologic variant: the papilliferous keratoameloblastoma which is the fifth reported case in the English literature.

scholarly journals TRANSPLANTATION OF TOOTH GERM ELEMENTS AND THE EXPERIMENTAL HETEROTOPIC FORMATION OF DENTIN AND ENAMEL

1934 ◽  
Vol 60 (2) ◽  
pp. 199-210 ◽  
Author(s):  
C. B. Huggins ◽  
H. R. McCarroll ◽  
A. A. Dahlberg
Keyword(s):  
Connective Tissue ◽  
Soft Tissues ◽  
Tooth Germ ◽  
Enamel Organ ◽  
Cylindrical Shape ◽  
Form And Function ◽  
Tissue Space ◽  
Pearl Formation ◽  
And Function ◽  
Connective Tissue Space

The formation of dentin and enamel in the abdominal wall in young pups was achieved by transplantation of the soft tissues of the developing tooth germ. An interesting finding was the cytomorphosis of the epithelium of the enamel organ. When this was transplanted so that the ameloblasts were in contact with the odontoblasts the cylindrical character of the epithelial cells was preserved and enamel was produced; otherwise the cylindrical shape of these cells was lost and a stratified epithelium resulted, resembling the gingival and certain tumors (the adamantinoma) of the jaw and related structures. This degenerated epithelium did not produce enamel and had an important characteristic of not forming cysts in a closed connective tissue space, instead forming islands and cords of cells with epithelial pearl formation. Thus the influence of mesodermic connective tissue derivatives on the form and function of epithelium is presented. The odonto-blasts were found capable of survival as such and readily formed new dentin in transplantation; the stellate cells of the pulp were inert from the standpoint of inducing calcification.

scholarly journals Application of cryopreservation to tooth germ transplantation for root development and tooth eruption

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Xinghan Li ◽  
Megumi Nakamura ◽  
Weidong Tian ◽  
Yasuyuki Sasano
Keyword(s):  
Periodontal Ligament ◽  
Root Elongation ◽  
Tooth Germ ◽  
Tooth Eruption ◽  
Enamel Organ ◽  
Micro Computed Tomography ◽  
Significant Difference ◽  
Old Donor ◽  
Tooth Germs ◽  
Tomography Analysis

AbstractWe cryopreserved mouse tooth germs with widely open cervical margins of the enamel organ to overcome difficulties in cryoprotectant permeation and tested their efficacy by transplanting them into recipient mice. The upper right first molar germs of 8-day-old donor mice were extracted and categorized into the following four groups according to cryopreservation time: no cryopreservation, 1 week, 1 month, and 3 months. The donor tooth germs were transplanted into the upper right first molar germ sockets of the 8-day-old recipient mice. The upper left first molars of the recipient mice were used as controls. The outcome of the transplantation was assessed at 1, 2, and 3 weeks after transplantation. Stereomicroscopic evaluation revealed that most of the transplanted teeth erupted by 3 weeks after transplantation. Micro-computed tomography analysis revealed root elongation in the transplanted groups as well as in the controls. There was no significant difference between the cryopreserved and non-cryopreserved transplanted teeth, but the roots of the cryopreserved teeth were significantly shorter than those of the control teeth. Histological examination revealed root and periodontal ligament formations in all the transplanted groups. These results suggest that the transplantation of cryopreserved tooth germs facilitates subsequent root elongation and tooth eruption.

scholarly journals Expression and Activity of Matrix Metalloproteinase-2 (MMP-2) in the development of rat first molar tooth germ

2002 ◽  
Vol 13 (2) ◽  
pp. 97-102 ◽  
Author(s):  
Paola Cotrim ◽  
Cleverton Roberto de Andrade ◽  
Sergio Line ◽  
Oslei Paes de Almeida ◽  
Ricardo D. Coletta
Keyword(s):  
Tooth Germ ◽  
Molar Tooth ◽  
Gelatinolytic Activity ◽  
Matrix Metalloproteinase 2 ◽  
Enamel Organ ◽  
Dental Papilla ◽  
Ca Ions ◽  
Old Rats ◽  
Activity Dependent ◽  
Expression And Activity

Tooth germ development is associated with morphological and biochemical changes of the dental papilla and enamel organ. Enzymes with gelatinolytic activities were studied by semiquantitative reverse transcriptase-polymerase chain reaction (RT-PCR) and enzymography in tooth germ of newborn to 15-day-old rats. Three major bands with gelatinolytic activity were detected at all periods and characterized as the latent and active forms of MMP-2 using their molecular weight and activity dependent on Zn++ and Ca++ ions as criteria. Expression and activity of MMP-2 increased progressively from 0 to 15 days after birth. Mechanical separation of the tooth germ from 10-day-old rats showed that the gelatinolytic activity was localized mainly in the dental papilla and not the dental organ. These data indicate that the expression and activity of MMP-2 varies during the development and maturation of rat first molar tooth germ.

scholarly journals Role of Innate Inflammation in the Regulation of Tissue Remodeling during Tooth Eruption

2021 ◽  
Vol 9 (1) ◽  
pp. 7
Author(s):  
Yusuke Makino ◽  
Kaoru Fujikawa ◽  
Miwako Matsuki-Fukushima ◽  
Satoshi Inoue ◽  
Masanori Nakamura
Keyword(s):  
Bacterial Infections ◽  
Tooth Movement ◽  
Tooth Eruption ◽  
Intercellular Adhesion Molecule ◽  
Enamel Organ ◽  
Pcr Analysis ◽  
Maturation Stage ◽  
Oral Epithelium ◽  
Rt Pcr ◽  
Inflammatory Reactions

Tooth eruption is characterized by a coordinated complex cascade of cellular and molecular events that promote tooth movement through the eruptive pathway. During tooth eruption, the stratum intermedium structurally changes to the papillary layer with tooth organ development. We previously reported intercellular adhesion molecule-1 (ICAM-1) expression on the papillary layer, which is the origin of the ICAM-1-positive junctional epithelium. ICAM-1 expression is induced by proinflammatory cytokines, including interleukin-1 and tumor necrosis factor. Inflammatory reactions induce tissue degradation. Therefore, this study aimed to examine whether inflammatory reactions are involved in tooth eruption. Reverse transcription-polymerase chain reaction (RT-PCR) analysis revealed sequential expression of hypoxia-induced factor-1α, interleukin-1β, and chemotactic factors, including keratinocyte-derived chemokine (KC) and macrophage inflammatory protein-2 (MIP-2), during tooth eruption. Consistent with the RT-PCR results, immunohistochemical analysis revealed KC and MIP-2 expression in the papillary layer cells of the enamel organ from the ameloblast maturation stage. Moreover, there was massive macrophage and neutrophil infiltration in the connective tissue between the tooth organ and oral epithelium during tooth eruption. These findings suggest that inflammatory reactions might be involved in the degradation of tissue overlying the tooth organ. Further, these reactions might be induced by hypoxia in the tissue overlying the tooth organ, which results from decreased capillaries in the tissue. Our findings indicate that bacterial infections are not associated with the eruption process. Therefore, tooth eruption might be regulated by innate inflammatory mechanisms.

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