Lecture 2

Question 1

histology

Answer 1

the study of the microscopic structures of tissue

Question 2

taking a closer look at the microscopic anatomy of the periodontium will give us a better understanding of

Answer 2

how the periodontium functions in health
changes that occur to the periodontium during the disease process

Question 3

microscopic anatomy of a tissue

Answer 3

cells: smallest structural unit of living matter
tissue: group of interconnected cells
4 types: epithelial, connective, muscle, nerve

Question 4

tissues of the periodontium

Answer 4

gingiva
periodontal ligament
cementum
alveolar bone

Question 5

extracellular matrix consists of

Answer 5

ground substance: gel-like substance surrounding tissue cells, nerves, blood vessels
fibers: collagen, elastin and reticular fibers

Question 6

the extracellular matrix provides

Answer 6

a framework giving connective tissue its strength to withstand mechanical forces

Question 7

the gingiva in health

Answer 7

stippled/attached gingiva tightly anchored to teeth and underlying bone

Question 8

the gingiva consists of both

Answer 8

epithelial tissue
connective tissue

Question 9

epithelial tissue

Answer 9

outer surface of skin
lines body cavities such as mouth, stomach, intestines
does not contain blood vessels

Question 10

what is made of stratified squamous epithelium

Answer 10

skin and oral mucosa

Question 11

stratified squamous epithelium is made of what cells

Answer 11

flat cells arranged in several layers

Question 12

gingival epithelium consists of

Answer 12

oral epithelium
sulcular epithelium
junctional epithelium

Question 13

oral epithelium

Answer 13

outer gingival epithelium
covers free and attached gingiva
gingival margin to MGJ
only part of the periodontium clinically visible
protective function so typically keratinized/parakeratinized
joins CT in a wavy interface via rete pegs

Question 14

sulcular epithelium

Answer 14

faces the tooth surface without contact
lines gingival sulcus (1-3mm)
gingival margin to the coronal edge of JE
thin (3 layers), non-keratinized (softer more flexible)
in health: smooth interface with CT
permeable to bacterial products and gingival crevicular fluid from CT

Question 15

junctional epithelium

Answer 15

forms base of sulcus and attaches the gingiva to the tooth surface
in health slightly coronal to CEJ
non-keratinized stratified squamous epithelium
smooth interface with CT in health
barrier between biofilm and CT

Question 16

basal lamina

Answer 16

thin layer of extracellular matrix providing attachment of epithelial cells to adjacent structures
OE to connective tissue
SE to CT
JE to CT and tooth surface: internal basal lamina (tooth), external basal lamina (CT)

Question 17

gingival connective tissue

Answer 17

more extracellular matrix with less cells
cells include: fibroblasts, mast, immune cells (macrophages, neutrophils, lymphocytes)
blood vessels and nerve supply
mostly collagen fibers (60%) produced by fibroblasts

Question 18

gingival connective tissue fibers

Answer 18

classification based on their orientations, insertion points, connecting structures
circular: encircle tooth
dentogingival: cementum into gingiva
dentoperiosteal: cementum into periosteum
alveologingival: periosteum into gingiva
transeptal: IP between adjacent teeth

Question 19

the attachment apparatus

Answer 19

periodontal ligament
cementum
alveolar process

Question 20

functions of the PDL

Answer 20

supportive: anchors tooth in socket
sensory: nerve fibers transmit tactile, pressure and pain sensations
transports nutrients
tissue development and maintenance

Question 21

periodontal ligament

Answer 21

rich nerve and blood supply
thin sheet of fibrous connective tissue

Question 22

components of the PDL

Answer 22

cellular element: fibroblasts, osteoblasts/osteoclasts, cementoblasts/cementoclasts

extracellular matrix: collagenous fibers: largest component of the PDL

Question 23

sharpey fibers

Answer 23

terminal portions of the principal fibers embedded in cementum and bone

Question 24

cementum

Answer 24

mineralized layer of connective tissue
no blood or nerve supply

Question 25

components of cementum

Answer 25

cells (cementoblasts/fibroblasts) extracellular ground substance (collagen fibers, mineralized portion) calcium + phosphate (hydroxyapatite crystals)

Question 26

types of cementum

Answer 26

acellular (primary): forms before tooth eruption, coronal + middle 1/3 of root, no production during life of tooth, no living cells) cellular (secondary): apical 1/3 of root + furcations, less calcified, contains cementoblasts/fibroblasts, deposited throughout life of tooth and increase in thickness with age

Question 27

alveolar process is composed of

Answer 27

mineralized connective tissue external cortical plates alveolar bone proper: inner socket wall cancellous/trabecular/bone

Question 28

alveolar process functions

Answer 28

protection: for the roots of teeth remodels: in response to mechanical forces or inflammation

Question 29

components of the alveolar process

Answer 29

cells: osteoblasts (synthesize), osteoclasts (resorb) extracellular matrix: collagen fibers, gel matrix (rigid B/C of hydroxyapatite) has blood vessels and nerve innervation

Question 30

blood supply to the periodontium how and via what arteries

Answer 30

transport oxygen and nutrients/remove carbon dioxide and waste products via major alveolar arteries: superior alveolar arteries (max), inferior alveolar arteries (mand)

Question 31

branch arteries function

Answer 31

supply blood to the teeth and periodontium

Question 32

branch arteries

Answer 32

intraseptal artery: enters socket supraperiosteal blood vessels: free gingiva subepithelial plexus: in CT beneath free and attached gingiva PDL vessels: PDL dentogingival plexus: network of blood vessels in CT beneath gingival sulcus

Question 33

a fine network of vessels supplies blood to

Answer 33

the gingiva, gingival connective tissue and periodontal ligament

Question 34

the rich blood supply to the gingiva accounts for

Answer 34

the dramatic color changes that are seen in gingivitis