Enamel Development Flashcards
When does the Bud stage occur?
6-9 weeks in utero
How many locations does the bud stage or initiatioon occur?
10 sites along the dental lamina in each jaw
What is it called when basal layer cells of the epithelium expand into mesenchyme?
The bud stage!
When does the cap stage occur and what is it called
9-11 weeks in utero, called proliferation!
What are the three parts of the cap stage?
- enamel organ
- Dental papilla = dentine and pulp!
- Dental sac = cementum and PDL
The basement membrane separates two things…
- the inner enamel epithelium from the dental papilla
2. the outer enamel epithelium from the dental sac
what is the dental sac
cementum and PDL!
what is stellate reticulum
polygonal cells between inner and outer enamel epithelium
What is the essential layer for enamel formation a nd where does it sit?
stratum intermedium
sits in between the inner enamel epithelium and the stratum reticulum
When does the bell stage occur and what can it be called
11-14 weeks in utero, histodifferentiation!
when is the advanced bell stage?
14-18 weeks
what happens in the advanced bell stage?
formation of enamel by ameloblasts
formation of dentin by odontoblasts
DEJ forms!
How does dentin form?
Formed at the DEJ!!! in the region near the cusps and moves APICALLY!!
Korff Fibers
Spiraling fibers that support dentine!
How does enamel form?
The ameloblasts lay down enamel OVER the dentin. the enamel formation proceeds CORONALLLY!
What forms Hertwig Epithelial Rooth Sheaths? (HERS)
the cervical portion of the enamel organ!
When are ameloblasts fully differentiated and secretory?
Tomes Process forms!!! this secretes and creates the enamel rod
Where does calcification start
cusp tips/incisal edge
morphodifferentiation
seems to be formation of ameloblasts and odontoblasts around DEJ
Apposition
initial dentin and enamel lay down
What stage is disturbed if you have hypodontia or anodontia and which teeth are most likely to be missing?
Initiation - Bud stage
3rds, upper laterals, 2nd premolars, lower centrals
What stage is disrupted with supernumery stage?
Initiation = bud stage
98% inthe maxilla!!!
Fusion vs Gemination
Fusion - joining of two tooth germs (reduced number of teeth!!)
gemination = two tooth buds from a single tooth germ
(normal number of teeth!)
What stage is disrupted if you have gemination or fusion
proliferation - cap stage!
