Teeth Dental Histo

Question 1

What is the portion of the tooth embedded in bone called?

Answer 1

tooth root

Question 2

What is the tooth grossly divided into ?

Answer 2

the root and crown

Question 3

What is the part of the tooth that is in part of the jaw?

Answer 3

alveolar ridge

Question 4

What is another word for the tooth socket?

Answer 4

alveolus

Question 5

What is the portion of the tooth that projects into the oral cavity?

Answer 5

crown

Question 6

What is the composition of enamel?

Answer 6

1% organic material
96-98% hydroxyapatite

Question 7

What secretes enamel?

Answer 7

tall, columnar ameloblasts of the enamel organ

Question 8

When do the ameloblasts degenerate?

Answer 8

when tooth erupts

Question 9

At what point can enamel no longer be replaced by new synthesis?

Answer 9

when the tooth erupts

Question 10

What is a tome’s process?

Answer 10

apical, secretory end of ameloblast that is a large, single process

Question 11

What does enamel mineratlization look like?

Answer 11

results in highly calcified enamel rods or prisms

Question 12

what do enamel rods look like ?

Answer 12

roughly hexagonal, 4-8 um in diameter

Question 13

What are the enamel rods/prisms separated by?

Answer 13

interprismatic material (less mineralized)

Question 14

Where do enamel rods extend to and from?

Answer 14

from ameloblasts to the enamel surface to dentino-enamel junction

Question 15

What is the bulk of the tooth composed of?

Answer 15

dentine

Question 16

What secretes dentine

Answer 16

odontoblasts of dental papilla

Question 17

How is dentine secreted?

Answer 17

as non-mineralized pre-dentine

Question 18

What is the composition of dentine?

Answer 18

70-80% hydroxyapatite
Type I collagen
GAGs

Question 19

What do the matrix vaculoes in dentine carry and what is their function?

Answer 19

Calcium and PO4-
- plays a key roles in mineralization of dentine matrix

Question 20

How is dentine arranged?

Answer 20

dentine tubules (hollow parallel tubes radiating from pulp cavity)

Question 21

What does the central pulp cavity contain?

Answer 21

-sensory nerves and blood vessels

Question 22

What innervated dentine?

Answer 22

myelinated nerves

Question 23

What embryonic layer is dental pulp from?

Answer 23

mesoderm

Question 24

What does the tooth root contain?

Answer 24

• stellate fibroblasts
• reticular fibers
• collagen
• ground substance

Question 25

What is the tooth root covered by?

Answer 25

thin layer of cementum

Question 26

What is cementum composed of?

Answer 26

45-50% hydroxyapatite

Question 27

What makes cementum?

Answer 27

cementoblasts that mature to cementocytes

Question 28

How do cementocytes makes more cementum?

Answer 28

one that lie against the surface of the periodontal ligament make via appositional growth

Question 29

What is the region of tooth between the root and crown?

Answer 29

neck

Question 30

What protects the neck of the tooth?

Answer 30

gingiva

Question 31

What does attached gingiva cover?

Answer 31

upper alveolar bone

Question 32

What does free gingiva cover?

Answer 32

forms cuff around neck of the tooth

Question 33

What is the space between the free gingiva and the crown called?

Answer 33

gingival sulcus

Question 34

What is crevicular epithelium?

Answer 34

lines the gingival sulcus with the thin layer (2-3 cells thick)

Question 35

What is the name of the tissues that surround and support the tooth?

Answer 35

periodontium

Question 36

What are the parts of the periodontium?

Answer 36

epithelium, cementum, periodontal ligament & alveolar bone

Question 37

What anchors the bone of alveolus to the cementum layer?

Answer 37

periodontal ligament - dense collageous fibers called Sharpey's fibers

Question 38

What allows for the slight movement of teeth during mastication?

Answer 38

periodontal ligament

Question 39

What are the clusters of epithelial cells within periodontal ligament?

Answer 39

vestigial epithelial rests (of Malassez)

Question 40

What in the tooth is from ectodermal origin?

Answer 40

enamel

Question 41

What cell layers are teeth made from?

Answer 41

-ameloblasts from enamel organ -odontoblasts of dental papilla

Question 42

What in the tooth is from mesodermal origin?

Answer 42

dentine, cementum, pulp, periodontal ligament

Question 43

When is there first some sign of tooth development?

Answer 43

6 weeks i.u. -a horseshoe shaped epithelial ridge from the oral epithelium

Question 44

What is the early bell stage of tooth development?

Answer 44

- create an enamel organ - loosely arranged stellate cells and peripheral layer of cuboidal/columnar epithelium - formation of internal enamel epithelium (ameloblasts) - form dental papillae with odontoblasts

Question 45

What does the internal enamel epithelium differentiate into?

Answer 45

a layer of ameloblasts and 2-3 layers of stratum intermedium

Question 46

What does the mesenchyme condense to form during the early bell stage?

Answer 46

dental papillae

Question 47

What is the layer of cells lining the outer convex surface of the enamel organ of tooth?

Answer 47

external enamel epithelium

Question 48

What is the layer of cells lining the concave surface on the outside of the enamel organ?

Answer 48

internal enamel epithelium (ameloblasts)

Question 49

What is amelogenesis?

Answer 49

enamel formation

Question 50

What is the layer deep to developing enamel?

Answer 50

dental papilla (odontoblasts)

Question 51

What do cells lining the convex surface of the dental papillae during odontogenesis?

Answer 51

odontoblasts

Question 52

What is dentinogenesis?

Answer 52

form dentine

Question 53

Development of ameloblasts induces what?

Answer 53

differntiation of odontoblasts

Question 54

What do odontobalst proccesses make?

Answer 54

dentine tubules

Question 55

Calcification of dentine induces what?

Answer 55

depositon of enamel

Question 56

What is tooth formation initiated by?

Answer 56

deposition of organic pre-dentine by odontoblasts

Question 57

Calcification of dentine matrx secondarily induces what?

Answer 57

enamel production by ameloblasts

Question 58

When does the enamel organ and ameloblasts degenerate?

Answer 58

tooth eruption

Question 59

When dental papilla shrinks what does it become?

Answer 59

dental pulp

Question 60

What is denta?

Answer 60

papillae enclosed by dentine to become to pulp cavity

Question 61

What does the Hertwig's root sheath do?

Answer 61

initiates the formation of dentine in the root

Question 62

What is a proliferation of epithelial cells located at the cervical loop of the enamel organ?

Answer 62

hertwig's root sheath

Question 63

After tooth formation is complete, small amounts of ________ continue to be produced.

Answer 63

2' dentine

Question 64

What can 2' dentine do?

Answer 64

may eventually obliterate the pulp cavity

Question 65

What does the surrounding mesenchym form around the hertwig sheath?

Answer 65

dental follicle (turns into periodontal ligament)

Question 66

What determines the cross sectional outline of the tooth?

Answer 66

sheath of Hertwig

Question 67

What does the surrounding mesenchyme form (enamel organ)?

Answer 67

dental follicle-> periodontal ligament

Question 68

When does tooth development start?

Answer 68

6th week of fetal development

Question 69

How many roots do incisor and canines have?

Answer 69

usually one

Question 70

How many primary teeth?

Answer 70

20

Question 71

When do permanent teeth replace primary?

Answer 71

6-12 years old

Question 72

When do teeth erupt (primary)?

Answer 72

6-30 months

Question 73

What does tetracycline cause in teeth?

Answer 73

yellow discoloration of teeth

Question 74

What is the human dental formula?

Answer 74

I 2/2, C 1/1, P 2/2, M 3/3

Question 75

What are some examples of dental disorders?

Answer 75

abnormal tooth eruption orthodontia dental caries periodontal disease gingivitis periodontitis

Question 76

What causes periodontal disease?

Answer 76

accumulation of calcified food & bacterial debris (plaque) in gingival sulcus - results in widening of gingival sulcus, possible inflammation & destruction of periodontal ligament

Question 77

Why do dental caries happen?

Answer 77

—results when weak acids in food & drink erode calcified enamel, augmented by bacterial action

Question 78

What helps to harden the enamel and kill bacteria?

Answer 78

fluoride

Question 79

What treatment happens when caries extend into dentine/pulp cavity and cause an abscess or death of tooth?

Answer 79

root canal

Question 80

What causes periodontal disease?

Answer 80

accumulation of calcified food and bacterial debris (plaque) in gingival sulcus

Question 81

What does periodontal disease cause?

Answer 81

widening of gingival sulcus, possible inflammation and destruction of periodontal ligament

Question 82

What is the inflammation of gums?

Answer 82

gingivitis

Question 83

What is the periodontitis?

Answer 83

inflammation of periodontal ligament

Question 84

How does tooth numbering work?

Answer 84

start on upper R wisdom tooth (1) -> upper L wisdom tooth (16) lower L wisdom tooth (17) -> lower R wisdom tooth (32)