(E1) 5 -Odontogenesis Part III: Root and Periodontitum Development

Question 1

With enamel thickness reached, ________ can occur

Answer 1

root formation

Question 1

During crown development enamel and dentin secretion occurs from the
_______ to the __________

Answer 1

• tip of the cusp
• cervical margin/tooth cervix

Question 2

Cervical margin is the future site of the ___________

Answer 2

Cementoenamel Junction

Question 3

What does HERS separate?

Answer 3

The two ectomesenchyme derived regions: dental papilla and dental follicle

• Remains open at the apical margin

Question 4

What is HERS integral to?

Answer 4

Question 5

Breakdown of HERS and radicular dentin deposition induces _______________

Answer 5

differentiation of the dental follicle

Question 6

What is HERS?

Answer 6

Question 7

What is the dental papilla?

Answer 7

Question 8

What is the dental follicle?

Answer 8

Question 9

What is the outcome of reciprocal induction?

Answer 9

Secretion and mineralization of hard tisses of the root (dentin and cementum)

Question 10

What is the functional period of deciduous teeth?

Answer 10

About 7-8 years

Question 11

Priamry Teeth: When does root development complete?

Answer 11

1.5 years after emerging into the oral cavity

Question 12

Permanent Teeth: When does root development complete?

Answer 12

About 3.5 years after emerging into the oral cavity

Question 13

Events of Root Formation - What is happening during initiation?

Answer 13

Question 14

Events of Differentiation of Odontoblasts - What layer induces this and where?

Answer 14

Question 15

Events of Deposition: Where do you find Predentin and Mineralized dentin?

Answer 15

Question 16

Events of Fragmentation of HERS: What induces it and what is left remaining?

Answer 16

Question 17

Events of Differentiation of Periodontium: What is exposed and what does this cause then?

Answer 17

Question 18

HERS grows ______

Answer 18

apically

Question 19

How does HERS regulate root formation?

Answer 19

Question 20

The rim of HERS (proliferating end) bends 45 degrees creating the ___________

Answer 20

epithelial diaphragm

Question 21

The epithelial diaphragm contributes to ______ (3 things)

Answer 21

Question 22

Initiation of Root Formation: Teeth with one root

Answer 22

Question 23

Initiation of Root Formation: Teeth with multiple roots

Answer 23

Question 24

What is Taurodontism?

Answer 24

Question 25

Cells of the IEE layer of HERS induce differentiation of _________ from outermost layer of dental papilla

Answer 25

odontoblasts (contributes to root lengthening)

Question 26

Odontoblasts secrete _______ adjacent to HERS

Answer 26

predentin matrix

Question 27

Predentin mineralizes into _______ adjacent to HERS

Answer 27

radicular dentin

Question 28

Dentin classified by time of deposition: Describe the two types.

Answer 28

Question 29

Describe dentin types based on location (4 types)

Answer 29

Question 30

After first layer of radicular dentin is formed, HERS layers separate into clusters of cells. What are the two possible outcomes?

Answer 30

Question 31

Epithelial cell rests function to ________ (4)

Answer 31

Question 32

Epithelial cell rests (ECR) may serve as stem cell sources to ______

Answer 32

Question 33

What is the result?

Answer 33

Question 34

What is included in the periodontium?

Answer 34

Includes cementum, PDL, alveolar bone

Question 35

What is the function of the periodontium?

Answer 35

Supporting and anchoring apparatus of the tooth

Question 36

Contact of dental follicle with newly-formed dentin induces differentiation. Describe what is happening in the three layers.

Answer 36

Question 37

When does the alveolar bone (tooth socket) begin forming?

Answer 37

During differentiation of the periodontium

Question 38

Describe what hapens due to an abnormal breakdown of HERS

Answer 38

Question 39

_______ is a thin layer of mineralized CT that covers the outer layer of the root

Answer 39

Cementum

Question 40

Functions of Cementum

Answer 40

Question 41

Describe Cementum - composition and presentation

Answer 41

Question 42

Location: Primary cementum

Answer 42

Cervical (coronal) 2/3

Question 43

Location: Secondary cementum

Answer 43

Mid to Apical 1/3 and around the furcation zone

Question 44

Location: Acellular Cementum

Answer 44

Cervical 2/3

Question 45

Location: Cellular Cementum

Answer 45

Apical 1/3

Question 46

Location: Extrinsic fiber cementum

Answer 46

Cervical 2/3

Question 47

Location: mixed fiber cementum

Answer 47

apical 1/3 and furcation zone

Question 48

Location: intrinsic fiber cementum

Answer 48

depends on the type of cementum

Question 49

First location of cementum is the ______

Answer 49

cementoenamel junction (CEJ)

Question 50

What are the three variations of cementum at the CEJ?

Answer 50

Question 51

Primary cementume provides anchor for ____ to ______

Answer 51

- tooth - alveolar bone

Question 52

Slow deposition of primary cementum allows ______ to become trapped within cementum

Answer 52

PDL fibers (Sharpey’s fibers)

Question 53

After _____, secondary cementum is secreted

Answer 53

Occlusion

Question 54

______ is a soft, specialized CT connecting the tooth to the alveolar bone

Answer 54

PDL

Question 55

Function of the PDL

Answer 55

Question 56

Functions of Alveolar Proper

Answer 56

Question 57

Osteoblasts cluster and secrete osteoid via _________

Answer 57

intramembranous ossification

Question 58

Describe Basal Bone

Answer 58

Question 59

Describe Alveolar Bone Proper

Answer 59

Question 60

What are the four stages of root development?

Answer 60