Development of Enamel 1

Question 1

Mature Enamel Properties

Answer 1

Non vascular

Acellular

Question 2

What helps Enamel since its so brittle?

Answer 2

Underlying dentin for support

Question 3

Explain thicknesses of Enamel

Answer 3

Thicker at crown

Thin at cervical line

Question 4

Enamel percentage composition by WEIGHT

Answer 4

96% Inorganic
3% Water
1% Organic

Question 5

What are the major enamel proteins

Answer 5

1) Amelogenins
2) Ameloblastins
3) Enamelin
4) Tuftelin

Question 6

Mineral Components of enamel

2

Answer 6

Hydroxyapatite

Carbonatoapatite

Question 7

Carbonate can substitute for what in namel?

Answer 7

Both Phospahte AND OH(sometimes)

Question 8

Hydroxyapatite can incorporate what odd metal?

Answer 8

Magnesium

Question 9

Carbonate and Magnesium are incorporated where in enamel?

Answer 9

Inner. Fluoride more outer

Question 10

Does enamel crystals run entire length of ename layer?

Answer 10

Yes

Question 11

enamel Rod def

Answer 11

Cylindrical accumulation of enamel crystals lined up along long axis of tooth

Question 12

In what direction do rods run in respect to DEJ

Answer 12

Perpendicular

Question 13

Are rods same as prisms?

Answer 13

Nope. Prism is more geometric

Question 14

How are enamel rods organized?

Answer 14

Into rods that run in alternating directions

Question 15

How many rods can 1 ameloblast make?

Answer 15

1 rod

Question 16

What are the 2 rod sheath proteins

Answer 16

Ameloblastins

Amelogenins

Question 17

What enamel component is much more prevalent in mammals than rodents

Answer 17

Rod sheath

Question 18

Caries are thought to penetrate where in enamel composition

Answer 18

Rod sheaths

Question 19

After the Inner Enamel Epithelium is formed, what is the stimullus for enamel to be formed?

Answer 19

Formation of pre-dentin by odontoblasts

Question 20

Ameloblast maturation has 3 phases

Answer 20

1) Pre-Secretory
2) Secretory
3) Maturation

Question 21

What happens duringPresecretory phase

Answer 21

Mature from pre-ameloblasts to ameloblasts

Question 22

What happens durng secretory phase

Answer 22

Deposition of enamel

Question 23

What happens durng Maturation

Answer 23

1) Reduction of organic matrix

2) Increase mineralization via ion transport

Question 24

Enamel is laid down in apposition to what?

Answer 24

To pre-dentin/mantle (first) dentin

Question 25

In what formation and held by what do the ameloblasts lay dentin?

Answer 25

Ameloblasts held together by Junctional complexes (terminal bars) move in sync to minimize gaps

Question 26

The initial ename laid due to apposition of dentin has what arrangement?

Answer 26

Uniform arrangement. Not rod arrangement

Question 27

Effectively what forms the enamel rod structure?

Answer 27

Tomes Process

Question 28

Tomes process proximal faces what?

Answer 28

Stratum intermedium

Question 29

Distal TOmes process faces what?

Answer 29

The forming enamel

Question 30

Interrod enamel and enamel rods come from what parts of tomes process?

Answer 30

Different parts

Question 31

What enamel is laid first by Tomes Process

Answer 31

Interrod

Question 32

Whats the process of laying enamel by Tomes Process

Answer 32

Interrod laid. It forms groove | Rod enamel laid in groove. Small gap around 3/4 of process fills with organic material and it forms the rod sheath

Question 33

Explain the culmination process of enamel deposition

Answer 33

Tomes Process retracts | Outer rods are straighter and outermost enamel is made without rods

Question 34

After enamel has been laid what happens to ameloblasts?

Answer 34

They become a squat cell (just lke a pre-ameloblast)

Question 35

After enamel has been laid what happens to tooth?

Answer 35

Loss of Stellate Reticulum Fuson of OEE and IEE The fusion results in a single layer of Reduced Enamel Epithelium

Question 36

What happens prior to eruption

Answer 36

Enamel hardens by removal of water and organic material

Question 37

How long does the pre-eruption hardening take

Answer 37

5 years. ABout 2/3 of amelogenesis is maturation

Question 38

After pre-eruption hardening what happens?

Answer 38

Production of basal Lamina at external enamel surface (not COllagen IV) Then Modulation

Question 39

What happens f basal lamina is disrupted?

Answer 39

Enamel Hypoplasia

Question 40

Modulation def

Answer 40

Process by which water and proteins are removed

Question 41

Ruffled cells

Answer 41

Infiltration of Calcium Ions into crystals

Question 42

Smooth cells do what

Answer 42

Allow diffusion of protein fragments out of enamel

Question 43

What happens to the enamel organ after ename maturation

Answer 43

Fuses to form REE Remnants fuse with oral epithelium forming covering for tooth. This forms a canal. This epithelial layer becomes the Dentogingival Junction

Question 44

Nasmyth's membrane def

Answer 44

layer of remaining debris on crown of tooth

Question 45

Primary Enamel cuticle def

Answer 45

Last secretory product of amelobalsts

Question 46

Secondary Enamel Cuticle aka

Answer 46

Dental Cuticle

Question 47

Secondary Enamel Cuticle def

Answer 47

Formed from remins of REE merged with Oral epithelium and removed by mechanical forces