Tooth Development Flashcards
What guides organogenesis?
Epithelial-mesenchymal interactions
What are the 4 types of cell communication?
1-Autocrine (cell on itself)
2-Paracrine (Cell on another near by)
3-Endocrine (carried by blood stream)
4-Intracrine (acts inside the cell rather than on receptors)
Migration of Neural crest cells to where is important for development of oral tissues?
1st arch
Ectomesenchyme (neural crest) is responsible for what parts of the dentition?
- Dentin
- Bone
- Cementum
- Periodontal ligament
What thickened band of cells early in development eventually give rise to teeth?
Dental lamina
An early bud off (successional dental lamina) of the larger forming tooth bud is likely to be what?
Succedaneous tooth (permanent tooth)
What are the 6 stages of Crown development?
1-Initiation (induction)
2-Bud stage (proliferation)
3-Cap stage (proliferation, differentiation, morphogenesis)
4-Bell stage (proliferation, differentiation, morphogenesis)
5-Apposition stage (induction and proliferation)
6-Maturation stage
The process whereby one tissue changes the development of surrounding tissues is called what?
induction
The inner area of the tooth germ is called what?
enamel organ
the condensed ectomesenchyme oaround the developing cap of the tooth germ is called what?
dental papilla
The location of differential genes where expression begins is called what?
the enamel knot
What are the four layers of the bell stage?
1-outer enamel epithelium (protects enamel organ)
2-stellate reticulum (star shaped, support enamel production)
3-stratum intermedium (separates layers, supports enamel mineralization)
4-inner enamel epithelium (becomes ameloblasts)
The junction of the outer and internal enamel epithelium is called what?
Cervical loop
What stimulates the pre-dental ectoderm to produce Fgf-8?
Lef-1
What induces the underlying mesenchyme to express Pax-9 and Msx-1 beneath the thickened dental lamina?
Fgf-8
What inhibits Fgf-8?
BMP-2 and 4
The dental sac later develops into what?
Periodontal tissue
The stage during which organic matrix of enamel and dentin are laid down is called what?
Appositional stage
What is the order of reciprocal induction?
- Inner Enamel Epithelial cells differentiate into pre-ameloblasts and become polarized
- Preameloblasts then include outer dental papilla cells to differentiate into preodontoblasts which turn into odontoblasts
Preameloblasts start producing enamel when then see what , produced by odontoblasts?
Predentin
What is formed once the basement membrane disintegrates?
Dentinoenamel junction (DEJ)
Tomes processes of late secretory ameloblasts form what?
Enamel prisms (prismless enamel is formed by early secretory ameloblasts)
Enamel matrix secreted by Ameloblasts immediately calcify to ______% of full mineralization
25%
What are the seven stages of ameloblast life cycle
1-Inner enamel epithelial cells
2-Preameloblasts (reverse polarity)
3-Initial secretory ameloblast (prismless enamel)
4-Secretory ameloblast (Tomes process/enamel process)
5-Smooth-ended maturation ameloblast (remove protein/water)
6-Ruffled-ended maturation ameloblast (introduction of inorganic material)
7-Protective ameloblast (enamel cuticle)
