Odontogenesis Flashcards
Extracellular molecules that can modify cell metabolism and gene expression
signaling molecules (ligands)
proteins that bind to specific DNA sequences, and regulate transcription of genetic information from DNA to RNA
transcription factors
____________ interactions are essential for tooth development
epithelial-mesenchymal
a congetial condition in which teeth form throughout the oral cavity
hyperdontia
determination of the dentition location is dependent on what
primary epithelial band
epithelial band forms by change in direction of cell divisions, which leads to what
thickening of the epithelium
what causes the formation of the primary epithelial band
epithelial thickening
primary band evolves into the dental placode which produces signaling molecules to attract ectomesenchyme cells which form ectomesenchymal condensation
1st induction iteration
where do dental and vestibular lamina originate from
dental placode
induction of the tooth germ by interplay between FGF8 (SP) and BMP (SP), via activation and inhibition of Pax9 (TF) expression
determination of positions of individual teeth
it is expressed in ectomesenchyme at the locations of future teeth
Pax9
activator of Pax9
FGF8
inhibitor of Pax9
BMP4 and BMP2
in the areas where mesenchyme expresses Pax9 invagination of the dental lamina takes place, leading to the formation of tooth buds
bug stage
what causes tooth anomalies
abnormal induction processes
what causes oligodontia
mutation in Pax9 gene
occurs during the bud stage and is regulated by ectomesenchyme
tooth type determination
bud to cap transition
morphogenesis and histodifferentiation
gives rise to dental papilla and dental follicle
ectomesenchymal condensation
a chamber at the end of the dental lamina invagination enclosing forming tooth tissues
formation of the enamel organ
future ameloblasts, stratum intermedium
inner enamel epithelium
cells commit to major dental tissues at what stage
late cap stage (histodifferentiation)
the dental papilla includes what structures
dentin and pulp
tooth supporting tissues like cementum, fibroblasts of PDL
dental follicle
a temporary structure containing stellate cells connected via long processes with high extracellular GAG content
stellate reticulum
arises by posterior growth of the general dental lamina
accessional lamina
the general dental lamina gives rise to what teeth
molars
what teeth arise from successional lamina of primary molars
permanent premolars, incisors, and canines
deepening of the enamel organ due to the cell proliferation at the inner-outer enamel epithelium junction (cervical loop)
bell stage
at what stage does the stratification of the enamel organ take place
bell stage
organizing center for crown morphogenesis appears at the late cap stage / early bell stage
crown patterning enamel knot
crown shape is largely determined by a number and position of what
enamel knots
is expressed in non-proliferating cells of the enamel knot, lacking FGF receptors, while other cells express FGF receptors
FGF-4
appear over the tips of the developing cusps in the early bell stage of tooth development
secondary enamel knots
primary and secondary enamel knots are associated with what
crown patterning
leads to uneven cell proliferation
gradient of FGF-4
formation of multi-rooted teeth occurs by what
fusion of hertwig’s root sheath folds in the plane of the primary apical foramen
