Development Of Tooth And Supportin Tissues Flashcards
Continuous horseshoe-band of thickened epithelium in the location of upper and lower jaws
Primary epithelial band
Thickening of the oral epithelium adjacent to condensation of ectomesenchyme
Dental lamina
2 subdivisions of primary epithelial band
Dental lamina
Vestibular lamina
How many stages are there in tooth development?
3 stages
Characterized by rounded, localized growth of epithelium surrounded by proliferating mesenchymal cells, which are packed closely beneath and around the epithelial buds
Bud stage
Condensation of the ectomesenchyme immediately subjacent to the tooth bud
Cap stage
It will eventually form the enamel
Enamel organ
Ball of condensed ectomesenchymal cells (it will form the dentin and pulp)
Dental papilla
This give rise to cementum and the periodontal ligament
Dental follicle or dental sac
Extension from the dental lamina that id connected to enamel organ
Lateral lamina
It is an artifact produced during sectioning of tissue
Enamel niche
Densely packed accumulation of cells projecting from the inner enamel epithelium into dental papilla
Enamel knot
Term used to constitute the structure that has enamel organ, dental papilla and dental follicle
Dental organ or tooth germ
Cluster of non dividing epithelial cells visible im section of molar cap stage
Enamel knot
First noted by expression of p21 gene expression
Enamel knot precursor cells
Temporary structures that disappear before enamel formation begins
Enamel knot or enamel cord
Stage where the enamel organ resembles a bell with deepening of the epithelium over dental papilla
Bell stage
Initiation of tooth development begins at?
37 days
Determination of specific tooth types at their correct position of jaws
Patterning
Teeth are all the same type
Homodont
Teeth have different shapes or forms
Heterodont
Packed closely beneath and around the epithelial bud
Supporting ectomesenchymal cells
Connection between the lateral lamina and developing tooth
Lateral lamina
A mass of similar epithelial cells transforms itself into morphologically and functionally distinct components
Period of histodifferentiation
Pulls water into the enamel organ
Glycosaminoglygan
Central part of the enamel organ
Stellate reticulum
The tooth crown assumes its final shape
Morphodifferentiation
Cells that will be making the hard tissues (ameloblast & odontoblasts) of the crown acquire their distinctive phenotype
Histodifferentiation
Cells at the periphery of enamel organ assume a low cuboidal shape
Outer enamel epithelium
Cells bordering on the dental papilla assume shorter columnar shape
Inner enamel epithelium
Where IEE and OEE meet at the rim of enamel organ
Zone of reflexion or cervical loop
Cells between IEE and Stellate Reticulum
Stratum Intermedium
Discrete cluster of epithelial cells that results from the fragmentation of the dental lamina
Epithelial pearls
Pioneer nerve fibers approach the developing tooth
Bud-to-cap stage
Target of the nerve fibers
Dental follicle
Nerve fibers penetrate the dental papilla
Dentinogenesis
Absent in the pioneer nerve fibers approaching the tooth germ
Autonomic nerve fibers
Permanent teeth arise from the??
Dental lamina
Embryonic development of entire primary dentition
6-8 weeks in utero
Successional permanent teeth
Week 20 - 10 mos after birth
Permanent molars
Week 20 - 5 years of age
How many enlargement or knobs will appear?
20
Inner enamel epithelium will later differentiate into?
Ameloblast
The peripheral cells of the mesenchymal dental papilla differentiate into?
Odontoblast
The basement membrane that separates the enamel organ and the dental papilla just prior to dentin formation is called?
Membrana preformativa
It will give rise to the epithelium for the root formation
Cervical loop
Pattern of enamel knot that extends between the inner and outer dental epithelium
Enamel cord
Hard tissue starts at what stage?
Late stage of bell stage
