lecture 2- perio anatomy 2 (junctional epithelium)

Question 1

after tooth eruption, cells of the oral epithelium possess the ability to differentiate into what?

Answer 1

Junctional epithelium

Question 2

JE (junctional epithelium) is widest in the _____ portion, and thin toward what tooth structure?

Answer 2

widest in the coronal portion

thins towards the CEJ

Question 3

T/F: the junctional epithelium is continuously renewed

Answer 3

true

Question 4

which cell type has a faster turnover rate: the oral epithelium or the junctional epithelium

Answer 4

junctional epithelium

Question 5

what are the dimensions of the JE? from what structure does it originate?

Answer 5

only about 1mm long (ranges from .5-1.5)

reduced enamel epithelium (in pre-erupted teeth) gives rise to the JE

Question 6

when comparing the JE to the OE, which has larger cells? which has larger intercellular spaces? which has more desmosomes?

Answer 6

Junctional epithelium- larger cells, larger intercellular space

Oral epithelium- more desmosomes

Question 7

T/F: JE has the potential to keratinize

Answer 7

true

Question 8

is the JE physically attached to the tooth, or just in contact with it?

Answer 8

physically attached

Question 9

the JE will move _______ in diseased epithelium

Answer 9

apically

Question 10

T/F: the JE if found just apical to the CEJ in children

Answer 10

False- found slightly coronal to the CEJ

moves to the level of the CEJ in healthy adults

Question 11

when does periodontitis occur?

Answer 11

when the Junctional epithelium migrates apically down the root surface

Question 12

what is necessary for pocket formation during periodontitis?

Answer 12

viable junctional epithelium

Question 13

Necrosis of junctional epithelium is seen during what condition?

Answer 13

Necrotizing ulcerative periodontitis (NUP)

Question 14

T/F: as cells die during JE necrosis, a large pocket is formed

Answer 14

FALSE

remember- you need viable (living) JE to have pocket formation

no pocket is formed during NUP

Question 15

what is exposed during NUP (necrotizing ulcerative periodontitis)

Answer 15

bone is exposed

Question 16

what cells are found in the lamina propria layer of the gingival CT?

Answer 16

• fibroblasts
• mast cells (M)
• macrophages
• neutrophilic granulocytes
• lymphocytes
• plasma cells

Question 17

what types of fibers are found in the lamina propria of the gingival CT?

Answer 17

• Collagen
• reticulin
• oxytalan
• elastic fibers

Question 18

what is the role of reticulin in the lamina propria?

Answer 18

surrounds blood vessels

keeps them upright

Question 19

what is the function of elastic fibers in the lamina propria?

Answer 19

keep the blood vessels of the CT open

Question 20

what cell types can produce collagen?

Answer 20

fibroblasts

cementoblasts

osteoblasts

Question 21

what is the role of gingival fibers?

Answer 21

• reinforce the gingiva
• provide resilience and tone
• maintain architectural form and integrity

Question 22

what is the role of circular fibers in the gingiva?

Answer 22

encircle the tooth like a cuff

Question 23

_________ fibers fan out from supra-crestal cementum into free gingiva

Answer 23

dentogingival fibers

Question 24

where do dentoperiosteal fibers run?

Answer 24

run from supracrestal cementum into attached gingiva

Question 25

________ fibers run from tooth to tooth (embedded in cementum)

Answer 25

transseptal fibers

Question 26

what are the characteristics of the periodontal ligament?

Answer 26

- richly vascular and cellular connective tissue | - surrounds the roots and joining cementum and alveolar bone

Question 27

where is the periodontal ligament seen in radiographs?

Answer 27

the space between the lamina dura (alveolar bone proper) and root surface (hourglass shape)

Question 28

what is the function of the periodontal lig?

Answer 28

- permits occlusal forces to be distributed | - essential for the tooth mobility

Question 29

what are the 4 fibers of the PDL?

Answer 29

Alveolar crest fibers (ACF) horizontal fibers (HF) oblique fibers (OF) apical fibers (APF)

Question 30

what type of cell is found aligned along the principal fibers of the PDL?

Answer 30

fibroblasts

Question 31

where are osteoblasts found?

Answer 31

lining bone surfaces

Question 32

_________ line cemental surfaces

Answer 32

cementoblasts

Question 33

_________ are multinucleated cells that create ruffled surfaces of bone

Answer 33

osteoclasts

Question 34

_________ are the remnants of the Hertwig's epithelial root sheath

Answer 34

epithelial rest cells of Mallassez

Question 35

Cementum is similar to bone, but has what key differences?

Answer 35

- no blood vessels - no lymph vessels - no innervation - no physiological resorption/remodeling

Question 36

T/F: cementum is continually deposited throughout life

Answer 36

true

Question 37

what is the structural composition of cementum?

Answer 37

collagen fibers embedded in an organic matrix

Question 38

what are the 3 classes of cemental fibers?

Answer 38

- intrinsic - extrinsic - "different forms"

Question 39

what produces intrinsic fibers of the cementum? how are these fibers oriented?

Answer 39

produced by cementoblasts composed of fibers oriented parallel to the root

Question 40

what are extrinsic cemental fibers also known as? what are they produced by?

Answer 40

- AKA "Sharpey's fibers" | - produced by PDL fibroblasts

Question 41

where is acellular cementum found? cellular cementum?

Answer 41

acellular cementum- coronal cellular- apical

Question 42

osteoblasts of alveolar bone produce a bone matrix (osteoid) consisting of what?

Answer 42

- collagen fibers - glycoproteins - proteoglycans

Question 43

In Alveolar bone, _______ undergo mineralization by the deposition of minerals

Answer 43

osteoids

Question 44

which dental tissue most closely resembles bone?

Answer 44

cementum