Oral Histo Flashcards
type of keratinization where stratum corneum retains the nucleus
parakeritinized
The neonatal line is located in
enamel and dentin
Hypomineralized ribbon like structures that run longitudinally to DEJ
Enamel tufts
Odontoblasts that extend into enamel
enamel spindles
hypomineralized enamel that contains proteins, proteoglycans, or lipids
enamel lamellae
Individual enamel rods extending in variable directions at the cusp tips
gnarled enamel
Enamel starts out at _______ percent mineralized and procedes to _______ percent.
30%
96%
Mineralization of enamel forms _______ crystals
hydroxyapatite
The de-differentiated ameloblasts, remnants of stratum intermedium, outer enamel epithelium, and stellae reticulum form the
reduced enamel epithelium(Nasmyth’s membrane)
Enamel hypoplasia
due to decreased in the amount of matrix
Dentinogenesis vs amelogenesis
Which has a set end point
Amelogenesis ends and remains static.
Dentinogenesis is lifelong
Dentinogenesis imperfecta
Type 1:
Type 2:
Type 3:
Teeth have enamel fracture away soon after eruption leaving brownish cast that is soft and unprotected.
Type1: Associated with osteogenesis imperfecta
Type2: Standard, doesn’t occur with other disease
Type 3: Rare inherited disorder.
The layer of dentin closest to the DEJ is _______ dentin. The remaining layer of primary dentin is called_______
mantle dentin
curcumpulpal dentin
Lines of Von Ebner are caused by
the change in direction of collagen fibers orientation every 5 days
Neonatal line in enamel is called
in dentin:
Enamel: line of retzius
dentin: Lines of owen
Difference between first, second, and third dentin
First and second are the same, but second is made later.
Tertiary is reactive dentin
Reactive vs reparative dentin
Reactive is made by old odontoblasts(tertiary)
Reparative is made from new mesenchymal cells that differentiated into odontoblasts
The downward growth of the _______ determines root number and form
epithelial root sheath
Intertubular dentin
Intratubular dentin
Globular dentin
IntErtubular: Normal mineralized dentin
IntrAtubular: Highly mineralized, no type 1 collagen
Globular: Hypomineralized dentin
Dentin and dental pulp are both derived from _______ _______ cells
neural crest cells
Describe the layers of pulp
Odontogenic zone has dentin forming odontoblasts
Cell free zone of Weil- Contains bundles of fibers, capilaries and nerves,
Cell rich zone- contains fibroblasts, Undifferentiated mesenchymal cells, and immune cells.
Deep Pulp- Plexus of rashcow(pain)
What is a false pulp stone
irregularly calcified tissue in the pulp as opposed to true which are tubular dentin.
percentage cementum is calcified
50-65%
Cementum is formed from the
dental follicle
