2/2/17 Tooth Development Dr. DSouza TEST 2

Question 1

If you have a 3rd layer of teeth what is that called?

Answer 1

-Cleidocranial Dysplasia

Question 2

If you have no teeth develop what is that called?

Answer 2

-Tooth Agenesis

Question 3

What interactions guide organogenesis?

Answer 3

-Epithelial (ectodermal)-mesenchymal

Question 4

What type of interactions dictate morphogenesis?

Answer 4

-Cell-Matrix

Question 5

What does the cranial neural crest give rise to?

Answer 5

• Ganglia and nerves
• Adrenal medulla
• Ectomesenchyme of bones and teeth

Question 6

When do the cranial neural crest cells migrate?

Answer 6

-37 days in utero

Question 7

What are the primary epithelial bands?

Answer 7

-Future ridges of the maxillary and mandibular teeth

Question 8

What are the thickenings in the primary epithelial bands that become the future teeth called?

Answer 8

-Dental Lamina

Question 9

What are the six stages of crown development?

Answer 9

• Initiation
• Bud stage
• Cap stage
• Bell stage
• Apposition stage
• Maturation stage

Question 10

What occurs in the initiation stage?

Answer 10

-Induction

Question 11

What occurs in the bud stage?

Answer 11

-Proliferation

Question 12

What occurs in the Cap stage?

Answer 12

• Proliferation
• Differentiation
• Morphogenesis

Question 13

What occurs in the Bell stage?

Answer 13

• Proliferation
• Differentiation
• Morphogenesis

Question 14

What occurs in the Apposition stage?

Answer 14

-Induction and proliferation

Question 15

What occurs at the maturation stage?

Answer 15

-Maturation

Question 16

What stage is the shape of the tooth developing?

Answer 16

-Cap and Early bell

Question 17

When the Dental lamina proliferates what does it give rise to?

Answer 17

-Tooth bud

Question 18

In the primary dentition how many buds will you have in each dental lamina?

Answer 18

-10

Question 19

What is each bud a precursor for?

Answer 19

-Enamel organ

Question 20

Define induction in the initiation stage.

Answer 20

-THe process whereby one tissue changes the development of surrounding tissues

Question 21

In tooth development Lef-1 stimulates the pre-dental ectoderm to produce what?

Answer 21

-Fgf-8

Question 22

In tooth development what stimulates the pre-dental ectoderm to produce Fgf-8?

Answer 22

-Lef-1

Question 23

What does Fgf-8 induce the underlying mesenchyme to express?

Answer 23

• Pax-9

- Msx-1

Question 24

What does BMP-2 and BMP-4 inhibit?

Answer 24

-Fgf-8

Question 25

When the mesenchymal cells pack tightly together by the tooth bud what are the mesenchymal called?

Answer 25

-Dental papilla

Question 26

In the Cap stage what causes the cap to form?

Answer 26

-Unequal proliferation of bud cells

Question 27

The Ectomesenchyme cells condense around the developing cap ultimately becoming what?

Answer 27

- Dental papilla | - Dental sac

Question 28

What three things make up the Tooth germ?

Answer 28

- Enamel organ - Dental papilla - Dental sac

Question 29

What forms on the lingual side of the dental lamina?

Answer 29

-Successional dental lamina

Question 30

What will the successional dental lamina give rise to?

Answer 30

-Enamel organs of the permanent teeth

Question 31

T/F | The enamel niche is an artifact and not a real structure of the enamel organ

Answer 31

True

Question 32

What influences the shape of the tooth?

Answer 32

-Mesenchyme

Question 33

What do the enamel knots ultimately become?

Answer 33

-Cusps

Question 34

What four distinct layers from from the enamel organ in the Bell stage?

Answer 34

- Outer enamel epithelium - Stellate reticulum - Stratum intermedium - Inner enamel epithelium

Question 35

What is the cervical loop in the bell stage?

Answer 35

-Junction of the Outer enamel epithelium and Inner enamel epithelium

Question 36

What do the dental papilla cells continue to proliferate into?

Answer 36

- Outer dental papilla cells | - Inner dental papilla cells

Question 37

What does the dental sac proliferate into eventually?

Answer 37

-Periodontal tissues

Question 38

What is the purpose of the outer enamel epithelium?

Answer 38

-Protective barrier for enamel organ

Question 39

What is the purpose of the stellate reticulum?

Answer 39

-Supports enamel production

Question 40

What is the purpose of the stratum intermedium?

Answer 40

-Supports enamel mineralization (alkaline phosphatase)

Question 41

What is the purpose of the inner enamel epithelium?

Answer 41

-Differentiate into ameloblasts

Question 42

What stage in crown development is the stage during which organic matrix of enamel and dentin are laid down followed by initial calcification?

Answer 42

-Apposition stage

Question 43

What stage do you have a series of reciprocal inductions occur between enamel organ and dental papilla outer cells?

Answer 43

-Apposition stage

Question 44

What is the first thing in the reciprocal induction order?

Answer 44

-IEE cells differentiate into Preameloblasts

Question 45

In the second step of reciprocal induction the preameloblasts induce what?

Answer 45

-Outer Dental papilla cells

Question 46

When the outer dental papilla cells are induced by preameloblasts what do they differentiate into?

Answer 46

-Preodontoblasts that continue to differentiate into odontoblasts

Question 47

When does the DEJ form?

Answer 47

-After disintegration of basement membrane

Question 48

When the odontoblasts retreat from the DEJ what do they leave behind?

Answer 48

-Odontoblastic processes within predentin

Question 49

What is the space containing the odontoblastic process called?

Answer 49

-Dentinal tubule

Question 50

What is formed by early secretory ameloblasts?

Answer 50

-Prismless enamel

Question 51

What are formed by Tomes processes of late secretory ameloblasts?

Answer 51

-Enamel prisms

Question 52

What does predentin induce?

Answer 52

-Differentiation of preameloblasts into ameloblasts

Question 53

How many stages are there in the ameloblast life cycle?

Answer 53

7

Question 54

What is the first stage of the ameloblast life cycle?

Answer 54

-Inner enamel epithelial cell

Question 55

In the life cycle of the ameloblast what comes after the IEE cell?

Answer 55

-Preameloblasts

Question 56

In the life cycle of the ameloblasts what comes after the preameloblasts?

Answer 56

-Initial secretory ameloblasts

Question 57

In the life cycle of the ameloblasts what comes after the initial secretory ameloblasts?

Answer 57

-Secretory ameloblasts

Question 58

In the life cycle of the ameloblasts what comes after the secretory ameloblasts?

Answer 58

-Smooth -ended maturation ameloblasts

Question 59

What do smooth ended maturation ameloblasts do?

Answer 59

-Removal of protein and water

Question 60

In the life cycle of the ameloblasts what comes after the smooth-ended maturation ameloblasts?

Answer 60

-Ruffled-ended maturation ameloblasts

Question 61

What does the ruffled-ended maturation ameloblasts do?

Answer 61

-Introduction of inorganic material

Question 62

In the life cycle of the ameloblasts what comes after the ruffled-ended maturation ameloblasts?

Answer 62

-Protective ameloblasts

Question 63

What is the protective ameloblast?

Answer 63

-Enamel cuticle