lecture 1- anatomy of the periodontium

Question 1

what are the 4 structures of the periodontium?

Answer 1

Gingiva

periodontal ligament

root cementum

alveolar bone

Question 2

what are the 2 regions of alveolar bone?

Answer 2

1) Alveolar bone proper (bundle bone)

2) alveolar process

Question 3

what is the function of the periodontium?

Answer 3

• attach the tooth to bony tissues of the jaw

- maintain integrity of masticatory mucosa

Question 4

cells of the periodontium originate from the ________ during development

Answer 4

neural crest (neural tube)

Question 5

during development, stomadeal epithelium releases factors which initiate what?

Answer 5

epithelial-ectomesenchymal interactions

Question 6

neural crest cells form ____________ beneath stomadeal epithelium

Answer 6

ectomesenchyme

Question 7

what does the dental papilla give rise to?

Answer 7

dentin and pulp

Question 8

what does the dental follicle form?

Answer 8

periodontium

Question 9

which embryonic structure gives rise to the periodontium

Answer 9

dental follicle

Question 10

the _________ determines the shape and form of a tooth

Answer 10

dental papilla

Question 11

what forms her twig’s epithelial root sheath?

Answer 11

outer and inner enamel epithelium proliferating apically

Question 12

what do the inner cells of the root sheath secrete?

Answer 12

enamel-related proteins (amelogenins)

Question 13

_____________ cells of the dental follicle contact root surfaces following the fenestration of the root sheath

Answer 13

ectomesenchymal

Question 14

________ induces differentiation of ectomesenchymal cells into cementoblasts

Answer 14

amelogenin

Question 15

the Periodontal ligament is formed by ________ that are differentiated from the dental follicle lateral to the cementum

Answer 15

fibroblasts

Question 16

_________ differentiate from dental follicle ectomesenchymal cells (alveolar bone proper)

Answer 16

osteoblasts

Question 17

T/F: ectomesenchymal cells are lost after maturation is complete

Answer 17

False: ectomesenchymal cells remain in mature periodontium and participate in turnover

Question 18

what are the 3 regions of gingiva?

Answer 18

1) free gingiva
2) attached gingiva
3) interdental papilla

Question 19

what is free gingiva also called? where does it extend to

Answer 19

AKA “gingival sulcus, marginal gingiva, sulcus depth”

extends from the free gingival margin to the free gingival groove

Question 20

the free gingival margin is the ______ end of the gingiva

Answer 20

coronal

Question 21

the Free gingival margin is located 1.5-2 mm coronal to what structure?

Answer 21

the CEJ

Question 22

the free gingival groove is the junction between which 2 structures?

Answer 22

junction between free and attached gingiva

Question 23

which gingival structure correlates to the CEJ in young, healthy adults

Answer 23

free gingival groove

only correlates in 30-40% of adults

Question 24

oral epithelium faces the ________

Answer 24

oral cavity

Question 25

which oral epithelium faces the tooth surface without contacting it?

Answer 25

oral sulcular epithelium

Question 26

____________ provides contact between gingiva and the tooth

Answer 26

junctional epithelium

Question 27

perio probing will show where the ________ begins

Answer 27

junctional epithelium

Question 28

what are the macroscopic limits of the free (marginal) gingiva?

Answer 28

extends from the: free gingival margin to the free gingival groove

Question 29

what is the MICROscopic limit of the free (marginal) gingiva?

Answer 29

extends from the free gingival margin to the junctional epithelium

Question 30

why do we care about the limits of the free (marginal) gingiva?

Answer 30

these landmarks change from health to disease will determine the accuracy of your probe readings

Question 31

attached gingiva is mainly attached to _________

Answer 31

alveolar bone

Question 32

T/F: the width of attached gingiva is fairly constant

Answer 32

False - increases with age - widest in incisors, narrowest in premolars (maxillary) - mandibular lingual: narrowest in incisors, widest in molars

Question 33

what is stippling? what % of the population shows stippling?

Answer 33

small depressions on the attached gingiva -found in 40% of adults

Question 34

what is the mucogingival junction? (MGJ) where is it NOT found?

Answer 34

-junction between attached gingiva and alveolar mucosa NOT found in the palate (palate is keratinized)

Question 35

attached gingiva and marginal gingiva are both ______ gingiva

Answer 35

keratinized

Question 36

T/F: alveolar mucosa is keratinized

Answer 36

False: its non-keratinized

Question 37

less than ___mm of attached gingiva will greatly increase the risk for gingival recession

Answer 37

2mm

Question 38

what determines the shape of interdental papilla?

Answer 38

- the contact relationship between adjacent teeth - width of approximate tooth surfaces - course of CEJ

Question 39

what is the "col"?

Answer 39

concavity seen in contact areas of premolar/molar region non-keratinized epithelium

Question 40

the bottom of the gingival sulcus in a healthy mouth is positioned apical to the CEJ: when is this condition most likely to occur?

Answer 40

at 40-60 years of age

Question 41

oral epithelium is made of what type of epithelium?

Answer 41

keratinized, stratified, squamous epithelium

Question 42

what are the layers of oral epithelium?

Answer 42

1) basal layer (stratum basale) 2) prickle cell layer (stratum spinosum) 3) granular cell layer (stratum granulosum) 4) keratinized cell layer (stratum corneum)

Question 43

orthokeratinized epithelium lacks what structure?

Answer 43

a nucleus

Question 44

what type of oral epithelial cells still have nuclear remnants?

Answer 44

parakeratinized

Question 45

what changes as we move from the basal layer to the granular layer of oral epithelium?

Answer 45

- cytoplasmic tonofilaments and the # of desmosomes INCREASE | - the number of organelles DECREASES

Question 46

keratinocytes make up what % of oral epithelium? clear cells?

Answer 46

keratinocytes- 90% clear cells- 10%

Question 47

what cell types make up the "clear cells" of the oral epithelium? what is the role of each of these cell types

Answer 47

- melanocytes (synthesize melanin pigment) - langerhans cells (defense cells) - Merkel's cells (sensory)

Question 48

characteristics of the basement membrane in oral epithelium:

Answer 48

- present between basal layer of oral epithelium and the connective tissue - rich in glycoproteins - 1-2 micrometers wide - contains protein-polysaccharide complexes

Question 49

what are the 2 layers of the basement membrane?

Answer 49

1) lamina lucida (LL) | 2) lamina densa (LD)

Question 50

which basement membrane layer sits adjacent to basal cells?

Answer 50

the lamina lucida

Question 51

the lamina densa sits adjacent to the _________

Answer 51

connective tissues **anchoring fibers project from the lamina densa into connective tissue

Question 52

what are hemidesmosomes?

Answer 52

dense plaques that attach epithelium to the basement membrane

Question 53

what is a pair of hemidesmosomes called?

Answer 53

a desmosome

Question 54

Connective tissue projects into the epithelium, forming ________

Answer 54

connective tissue papillae

Question 55

what is the name for the epithelial ridges that intervene between CT papillae?

Answer 55

rete pegs

Question 56

when rete pegs fuse it as seen as ______

Answer 56

stippling

Question 57

where are rete pegs missing?

Answer 57

at the junctional epithelium

Question 58

what cell type is the most common defense cell of the oral epithelium?

Answer 58

Langerhans cells (a type of clear cells)

Question 59

T/F: the "col" of the oral epithelium is keratinized

Answer 59

FALSE- its non-keratinized since it is protected from abrasive forces in the mouth, it remains non-keratinized

Question 60

what happens to the col after extraction?

Answer 60

it recedes into a flat, keratinized section of oral epithelium