Lecture 1

Question 1

what are the other names of periodontium?

Answer 1

attachment apparatus

supporting tissues of the tooth

Question 2

what are the functions of the periodontium?

Answer 2

attach the tooth to bony tissue of the jaw

maintain integrity of masticatory mucosa

Question 3

when does the periodontium development occur?

Answer 3

early in the embryonic phase

occurs along with tooth development

Question 4

where do the cells of periodontium originate from?

Answer 4

neural crest (neural tube)

Question 5

what happens to the cells of the periodontium?

Answer 5

cells from the neural crest migrate into the first branchial arch

Question 6

what do the cells of periodontium form?

Answer 6

ectomesenchyme beneath stomadeal epithelium

Question 7

what does the stomadeal epithelium do?

Answer 7

releases factors which initiate epithelial ectomesenchymal interactions

Question 8

what do the dental lamina form?

Answer 8

bud stage, cap stage, bell stage

Question 9

what happens to the ectomesenchyme?

Answer 9

ectomesenchyme condenses around dental organ and forms the dental papilla and dental follicle

Question 10

what does the dental papilla do?

Answer 10

give rise to dentin and pulp

determines the shape and form of tooth

Question 11

what does the dental follicle do?

Answer 11

gives rise to periodontium

Question 12

what forms first in embryogenesis?

Answer 12

crown forms first

Question 13

what does the outer and inner enamel epithelium proliferate apically and form?

Answer 13

Hertwig’s epithelial root sheath

Question 14

what forms dentin?

Answer 14

odontoblast

Question 15

what does the inner cells of root sheath secrete?

Answer 15

enamel related proteins (amelogenins)

Question 16

what happens to the root sheath?

Answer 16

fenestrates

Question 17

what contacts the root surface?

Answer 17

ectomesenchymal cells of folicle

Question 18

what happens to the ectomesenchymal cells of follicle?

Answer 18

amelogin induces differentiation into cementoblast and cementoid forms

Question 19

what does the fibers of cementoid intermingle with?

Answer 19

immature dentinal fibers

Question 20

what are the periodontal ligaments formed by?

Answer 20

fibroblast

Question 21

where do the fibroblast differentiate from?

Answer 21

dental follicle lateral to the cementum

Question 22

where do the osteoblasts differentiate from?

Answer 22

dental follicle ectomesenchymal cells

Question 23

what happens to the ectomesenchymal cells?**

Answer 23

remain in mature periodontium and participate in turnover

Question 24

what is the definition of gingiva?

Answer 24

part of the masticatory mucosa which covers the alveolar process and surrounds the cervical portion of the teeth

Question 25

what are the three parts of the gingiva?

Answer 25

free gingiva, attached gingiva and interdental papilla

Question 26

what are synonyms for free gingiva?

Answer 26

gingival sulcus, marginal gingiva, sulcus depth

Question 27

what are the margins of free gingiva?

Answer 27

extends from free gingival margin and free gingival groove

Question 28

what is the free gingiva made of?

Answer 28

keratinized epithelium

Question 29

what s the free gingival margin?

Answer 29

coronal end of gingiva- located 1.5-2mm coronal to CEJ

Question 30

what is the free gingival groove?

Answer 30

junction between free and attached gingiva | corresponds to CEJ- only found in 30-40% of adults

Question 31

what are the components of gingival epithelium?

Answer 31

oral epithelium oral sulcular epithelium junctional epithelium

Question 32

where is the oral epithelium?

Answer 32

faces oral cavity

Question 33

where is the oral sulcular epithelium?

Answer 33

faces tooth surface without contacting it

Question 34

where is the junctional epithelium? **

Answer 34

provides contact between gingiva and the tooth

Question 35

what is the macroscopic limit of the free gingiva?

Answer 35

extends from free gingival margin to free gingiva groove

Question 36

what is the microscopic limit of free gingiva?

Answer 36

extends from free gingival margin to junctional epithelium

Question 37

what are the characteristics of attached gingiva?

Answer 37

firm texture, coral pink, immobile, keratinized

Question 38

how does the attached gingiva width vary?

Answer 38

increases with age (passive eruption) widest in incisors, narrowest in premolars mandibular lingual- lowest in incisors, widest in molars

Question 39

what is stippling?

Answer 39

small depressions on the attached gingiva | 40% of adults present stippling

Question 40

what is the mucogingival junction?

Answer 40

junction between attached gingiva and alveolar mucosa

Question 41

where does the mucogingival junction not exist?

Answer 41

not in the palate

Question 42

what does the shape of interdental papilla depend on?

Answer 42

the contact relationships between adjacent teeth width of approximal tooth surfaces course of CEJ

Question 43

what is the col?

Answer 43

concavity seen in contact areas of premolar/ molar region | non-keratinized epithelium (similar to junctional epithelium)

Question 44

what is the oral epithelium?

Answer 44

keratinized, stratified, squamous epithelium (keratinocytes)

Question 45

what are the layers of the oral epithelium?

Answer 45

basal layer prickle cell layer granular cell layer keratinized cell layer

Question 46

what is orthokeratinized?

Answer 46

no nucleus

Question 47

what is parakeratinized

Answer 47

nuclear remnants

Question 48

what happens from the basal layer to the granular layer?

Answer 48

cytoplasmic tonofilaments and number of desmosomes increase | number of organelles increase

Question 49

what are the cells of the oral epithelium?

Answer 49

keratinocytes (90%) | clear cells

Question 50

what are clear cells?

Answer 50

melanocytes, langerhans cells, merkel's cells

Question 51

what do melanocytes do?

Answer 51

synthesize melanin pigment

Question 52

what do langerhans cells do?

Answer 52

defense cells

Question 53

what do merkel cells do?

Answer 53

sensory

Question 54

what is the basement membrane?

Answer 54

present between basal layer of oral epithelium and CT 1-2 um wide rich in glycoproteins contains protein-polysaccharide complexes

Question 55

what are the 2 layers of basement membrane seen microscopically?

Answer 55

lamina lucida- adjacent to basal cells | lamina densa- adjacent to connective tissue

Question 56

what does the lamina densa project?

Answer 56

anchoring fibers project into connective tissue

Question 57

what are hemidesmosomes?

Answer 57

dense plaques that attach epithelium to the basement membrane

Question 58

what are desmosomes?

Answer 58

pairs of hemidesmosomes

Question 59

how does stippling form?

Answer 59

in the boundary between oral epithelium and underlying connective tissue, connective tissue projects into epithelium connetic tissue papillea with epithelial ridges or rete pegs intervening. when rete pegs fuse- stippling

Question 60

where are rete pegs missing from

Answer 60

junctional epithelium site