Dental Hygiene Anatomy Exam #3 Ch 6

Front 1

When does odontogenesis begin?

Back 1

6th and 7th week in embryo

Front 2

Name the stages of tooth formation

Back 2

Initiation Stage, Bud Stage, Cap Stage, Bell Stage, Maturation Stage

Front 3

How is the dental lamina formed and what will form there later?

Back 3

formed from the invagination of oral epithelium into the ectomesenchyme. teeth will form there

Front 4

What is induction?

Back 4

theactive interaction between embryologic tissues

Front 5

What does the outer ectoderm of an embryo's stomodeum give rise to?

Back 5

Oral epithelium

Front 6

What separates the oral epithelium and the ectomesenchyme?

Back 6

a basment membrane

Front 7

What is anodontia

Back 7

missing teeth as a result of the lack of initiaion within the dental lamina

Front 8

What are some common physical signs of ectodermal dysplasia?

Back 8

cone shaped teeth, no hair, can't sweat

Front 9

When does the bud stage begin?

Back 9

8th week

Front 10

What main physiological process occurs in the initiation stage?

Back 10

induction

Front 11

What main physiological process occurs in the bud stage?

Back 11

proliferation

Front 12

Describe the proliferation in the bud stage

Back 12

the dental lamina proliferates into buds or oval masses that penetrate into the mesenchyme.Both the future maxillary arch and mandibular arch will have 10 buds each

Front 13

What makes up the tooth germ?

Back 13

enamel organ, dental papilla and dental sac

Front 14

When does the cap stage occur?

Back 14

9th and 10th week

Front 15

What physiological process occurs during the cap stage?

Back 15

morphogenesis

Front 16

What is the enamel organ?

Back 16

a depression in the deepest part of each tooth bud of dental lamina forming the cap

Front 17

What is the enamel knot?

Back 17

The innermost margin of the cap shape of the enamel organ

Front 18

How is the dental papilla formed?

Back 18

a part of the ectomesenchyme deep to the buds condenses into a mass within the concavity of the cap of the enamel organ

Front 19

What does the dental papilla later produce?

Back 19

dentin and pulp

Front 20

The basement membrane between the enamel organ and the dental papilla later becomes what?

Back 20

the site of the future dentinoenamel junction

Front 21

What is the dental sac?

Back 21

the remaining ectomesenchyme surrounding the outised of the cap or enamel organ

Front 22

The dental sac is also referred to as:

Back 22

the dental follicle

Front 23

What does the dental sac later produce?

Back 23

The periodontium: cementum, periodontal ligament and alverolar bone

Front 24

When does the bell stage occur?

Back 24

11th and 12th week

Front 25

What is the main physiological process that occurs in the bell stage? And why is it called that?

Back 25

Differentiation. Because at the end of this stage, 4 different types of cells are found within the enamel organ

Front 26

What are the 4 different cell types found at the end of the bell stage?

Back 26

1. Inner Enamel Epithelium (IEE) 2. Outer Enamel Epithelium (OEE) 3. Stellate reticulum 4. Stratum intermedium

Front 27

What shape are the OEE cells?

Back 27

cuboidal

Front 28

What shape are the IEE cells?

Back 28

tall columnar

Front 29

What kind of cells do the IEE differentiate into?

Back 29

ameloblasts

Front 30

What are the star shaped cells called?

Back 30

Stellate reticulum

Front 31

What are the innermost cells of the enamel organ called?

Back 31

Stratum intermedium

Front 32

The dental papilla differentiates into what 2 layers?

Back 32

1. Outer cells of the dental papilla 2. Central cells of the dental papilla

Front 33

What creates dentin and where does it originate from?

Back 33

odontoblasts coming from the outer cells of the dental papilla

Front 34

Which layer of dental papilla becomes the pulp?

Back 34

Central cells of the dental papilla

Front 35

What is an extracellular substance that is partially mineralized and serves as a framework for later mineralization?

Back 35

dental matrix

Front 36

When is the stage of maturation reached?

Back 36

When the matrices of the hard dental tissue types are fully mineralized.

Front 37

preameloblasts differentiate from...?

Back 37

IEE

Front 38

The movement of cells' nuclei in the IEE cells is referred to as...?

Back 38

repolarization

Front 39

preameloblasts have two distinct roles in odontogenesis. What are they?

Back 39

1. they induce the Outer cells of the dental papilla to differentiate into odontoblasts 2.then the preameloblasts differentiate into ameloblasts

Front 40

Which cells begin their roles first? Odontoblasts or Ameloblasts?

Back 40

Odontoblasts

Front 41

What must occur for the preameloblasts to differentiate into ameloblasts?

Back 41

The basement membrane between the preameloblasts and the odontoblasts must disintegrate and the contact between them now is what induces the change

Front 42

What is dentinogenesis?

Back 42

The apposition of predentin (or dentin matrix)

Front 43

What is amelogenesis?

Back 43

The apposition of enamel matrix

Front 44

What is the angled part of each ameloblast that is created as the ameloblasts move away from the dentin interface?

Back 44

Tomes' process

Front 45

What does the Tomes' process secret?

Back 45

the enamel matrix

Front 46

As the odontoblasts move away from the DEJ, they leave attached cellular processes called _______ that are contained in a mineralized cylinder called ______.

Back 46

odontoblastic process, dentinal tubule

Front 47

When does root development begin?

Back 47

Long after the crown is completely shaped and the tooth is starting to erupt into the oral cavity

Front 48

What is responsible for root formation?

Back 48

The cervical loop

Front 49

What makes up the cervical loop?

Back 49

IEE and OEE

Front 50

What is the function of HERS?

Back 50

to shape the root(s) by inducing dentin formation in the root area so that it is continuous with coronal dentin

Front 51

When does cementogenesis occur?

Back 51

After HERS disintegrates

Front 52

When dental sac cells and and the dentin surface of the root make contact, the dental sac cells differentiate into what?

Back 52

cementoblasts

Front 53

What is cementoid?

Back 53

the cementum matrix that later mineralizes to form cementum

Front 54

What are cementocytes?

Back 54

cementoblasts that become entrapped by the cementum they produce

Front 55

What are Sharpey's Fibers?

Back 55

PDL fibers that are formed from collagen fibers from the mesenchyme cells of the dental sac

Front 56

How is the alveolar bone formed?

Back 56

Mesenchyme cells from the dental sac differentiate into osteoblasts which produce the alveolar bone

Front 57

What is active eruption?

Back 57

the actual vertical movement of the tooth

Front 58

What is the dental cuticle and what produces it?

Back 58

An acellular matrix that covers the enamel before tooth eruption. It is produced by ameloblasts

Front 59

What is the eruption rate?

Back 59

1mm/3months

Front 60

Describe how the tooth actively erupts

Back 60

REE forms over the enamel surface of the tooth and fuses with the oral epithelium. Enzymes from the REE disintegrate a small hole in the oral cavity lining for the tooth to erupt through

Front 61

The REE peels off the crown and only remains where? What does this portion become?

Back 61

It only remains attached at the CEJ and serves as the temporary junctional epithelium

Front 62

What is Nasmyth's membrane?

Back 62

A green-gray residue that may be on the newly erupted teeth causing it to look stained. It is made up of REE, oral epithelium and the dental cuticle

Front 63

Where do the succedaneous teeth usually erupt? Which ones are the exceptions?

Back 63

On the lingual side, except for the maxillary incisors which erupt facially

Front 64

What is the REE composed of?

Back 64

Outer enamel epithelium, stellate reticulum and stratum intermedium

Front 65

What do odontoclasts do?

Back 65

Resorb dentin, cementum and even enamel

Front 66

What is the definition of tooth eruption?

Back 66

a combination of bodily movement of teeth, which brings them into occlusion

Front 67

What is dens in dente?

Back 67

can be caused during cap stage. "Tooth within a tooth"

Front 68

What is gemination?

Back 68

When the tooth germ tries unsuccessfully to divide. Only has one pulp cavity but looks like 2 teeth at the crown

Front 69

What is fusion?

Back 69

When two adjacent teeth fuse together but still have 2 pulp cavities. Looks like a giant tooth. The enamel, dentin and pulp are united, but still 2 pulp cavities

Front 70

What is enamel hypoplasia?

Back 70

When there is a reduction in the quantity of enamel matrix so the tooth looks pitted and has grooves

Front 71

What is amelogenesis imperfecta?

Back 71

When the teeth have very thin enamel that chips off or no enamel at all

Front 72

What is concrescence?

Back 72

excessive cementum formation that binds two teeth at the roots

Front 73

What is dilacerations?

Back 73

bent roots

Front 74

What is taurodontism?

Back 74

huge pulp chamber