histology of the gingiva & gingival CT (lamina propria)

Question 1

3 parts of gingival epithelium

Answer 1

oral, sulcular, junctional

• *epithelium = surface, outer layer that covers the connective tissues (muscles, fibers, etc)
• *all 3 parts are continuous, but different

Question 2

oral epithelium, strata

Answer 2

-faces oral cavity and extends from gingival margin to mucogingival jxn

1. strata basale: contact with CT - capable of cell division
2. strata spinosum: spines
   * *cells shrink away from one another yet stay in contact via desmosomes
3. strata granulosum: keratohyalin granules
4. strata corneum: keratinized, no nuclei (ortho) or nuclei/incomplete (para)

Question 3

oral epithelium - connective tissue attachments

Answer 3

• light microscopy: see basement membrane of connective tissue
• CT of lamina propriae (papillae) interdigitates with epithelial rete pegs
• deep numerous epithelial rete pegs: increase surface area for better attachment
• comprised of HEMIDESMOSOMES, lamina lucida, lamina densa, anchoring fibrils, collagen fibers

Question 4

oral epithelium - CT attachment, on elec microscope

Answer 4

• you see basal lamina epithelial cells and a whitish not as dense layer called lamina lucida
• then a darker line, lamina densa
• *ALL CT FIBERS CONNECT TO LAMINA DENSA

Question 5

keratinized: ortho vs para

Answer 5

ortho: no nuclei
para: nuclei still in these flattened cells, incomplete keratinization

Question 6

oral epithelium cell renewal

Answer 6

• *10 days**
  1. lose ability to divide
  2. produce increasing amounts of protein and keratin
  3. lose ability to produce protein, keratin, and energy source
  4. becomes dehydrated/flat, lose nuclei, become filled with keratin, maintain desmosomes
  5. sloughed away into oral cavity as desmosomes degenerate

Question 7

other cells of oral epithelium

Answer 7

1. melanocytes: make melanin
2. langerhans cells: macrophage like cell, regulate tissue function
3. merkel cell: tactile sensory
4. lymphocyte: inflammatory response

Question 8

sulcular epithelium

Answer 8

-faces enamel from gingival margin to junctional epithelium
-non keratinized
strata:
1. basale
2. spinosum
3. intermediate - flat cells with nuclei adn organelles
4. superficial - flat cells with organelles, no nuclei, slough off cell into sulcular fluid

**probably 25-30 cells thick

Question 9

sulcular epithelium - light microscopy, what do you see

Answer 9

• reduced rete pegs (should be smooth in health)
• relatively flat interface
• basement membrane between epithelium and CT

Question 10

junctional epithelium

Answer 10

• collar like band of epithelium that surrounds the tooth
• attached to both tooth and CT
• few desmosomes between cells, few intercellular spaces
• *thickest at coronal part (15-30 cell layers) and tapers as you go apical
• flat cells with long axis parallel to long axis of tooth

Question 11

jxnal epithelium - why so few desmosomes

Answer 11

• cells move super fast (4 days to get across)
• very dynamic, always moving and changing
• lots of intercellular space

Question 12

where is jxnal epithelium

Answer 12

usually overlaps CEJ

Question 13

where is junctional epithelium thickest

Answer 13

at most coronal part (15-30 cell layers) and tapers as it goes apical

Question 14

jxnal epithelium - cell renewal

Answer 14

• *4 days**
• mitotic activity in all layers
• cells move towards adn along tooths surface in coronal direction
• migrate at oblique angle, not 90deg like oral epithelium
• continuously attached to tooth

Question 15

JE - CT attachment

Answer 15

• attaches epithelium to tooth surface (cementum)
• comprised of hemidesmosomes, lamina lucida, and lamina densa
• lamina densa adjacent to tooth
• light microscopy: you see basement membrane, no rete pegs, flat interface

Question 16

what does JE attach to?

Answer 16

either enamel or cementum — has hemidesomosomes, lamina densa, lamina lucida
(lamina densa adjacent to tooth)
NO DESMOSOMES

Question 17

gingival connective tissue

Answer 17

• primary cell is fibroblast, which makes the primary protein, collagen
• multiple collagen fibers are long like noodles – provides support/shape of gingiva and attachment of tissue to bone/tooth

Question 18

collagen

Answer 18

primary protein in gingival connective tissue, 60%

made by fibroblast

Question 19

gingival fibers - circular, gingivodental, transseptal

Answer 19

1. circular: maintain contour and position of marginal gingiva; encircle gingiva in ring like fashion
2. gingivodental: from gingiva to tooth, provide gingival support
3. transseptal: across septum, from cementum of one tooth to cementum of adjacnet tooth, maintain relationship of adjacent teeth, protects interproximal bone

Question 20

circular fibers

Answer 20

maintain contour and position of marginal gingiva, encircles gingiva in ring link fashion

Question 21

gingivodental fibers

Answer 21

from gingiva to tooth, provides gingival support

Question 22

transseptal fibers

Answer 22

• across septum/interproximal space
• from cementum of one tooth to cementum of next
• maintain relationship of adjacent teeth
• protects interproximal bone

Question 23

alveolo-gingival fibers

Answer 23

from alveolus to gingiva; attach gingiva to bone

Question 24

periosteogingival fibers

Answer 24

attach gingiva to bone

Question 25

transgingival fibers

Answer 25

- like circular, but all intertwined | - secure alignment of teeth in arch

Question 26

interpapillary fibers

Answer 26

- from tissue in papilla to gingiva | - provide support for interdental gingiva

Question 27

intercircular fibers

Answer 27

- like circle, but they skip a tooth | - secure alignment of teeth in arch

Question 28

intergingival fibers

Answer 28

-provide support and countour of attached giingiva

Question 29

how does papilla get swollen adn enlarged?

Answer 29

extracellular fluid, which cannot get in until collagen fibers start to break down bc they are held so tightly together

Question 30

gingival crevicular fluid

Answer 30

-from gingival sulcus -consists of amino acids, plasmids, plasma proteins (including Ab's), electrolytes ^^^but in a different ratio than serum -minimal amounts in healthy gingiva bc more structured/ impermeable sulcular epithelium -increased amounts when inflamed

Question 31

attachment level (loss)

Answer 31

- histological: epithelium and CT; see where jxnal epithelium ends relative to CEJ but you cannot see exactly where enamel stops - clinical: based on measurement using fixed reference point--CEJ; distance from CEJ to base of pocket; pocket depth + distance from gingival margin to CEJ

Question 32

what does it mean if you cannot find CEJ with probe

Answer 32

- jxnal epithelium is at or above CEJ | - this means no clinical attachment loss

Question 33

lamina propria

Answer 33

gingival connective tissue