Anatomy Ii Week 7: Periodontium, Pulp

Front 1

Periodontium: components (5)

Back 1

-gingiva
-junctional/sulcular epithelia
-alveolar bone proper (lamina dura?)
-periodontal lig
-cementum

Front 2

attachment apparatus: components (4)

Back 2

-junctional epith
-alv bone proper
-perio lig
-cementum
(i.e.: periodontium minus gingiva)

Front 3

cementum: types (8)

Back 3

-primary vs. secondary (time)
-cellular vs. acellular (cells w/in matrix)
-intrinsic vs. mixed fiber (origin of collagen fibers)
-fibrillar vs. afibrillar (presence/lack of collagen)

Front 4

Where is primary acellular cementum found
function

Back 4

-cervical 1/2-2/3 of root
-anchors tooth, adapts root (along w/ 2ndary mixed fiber cellular cementum)

Front 5

what type of cementum is found in the apical 1/3-1/2 of the root?
function

Back 5

-2ndary mixed fiber cellular cementum
-along with primary acellular c. , anchors tooth and adapts root (following eruption/tooth movement)

Front 6

CEJ: stats (3)

Back 6

-variable
-60% has cementum enamel overlap
-30% perfect
-10% has small gap

Front 7

periodontal lig:
composition
function (6)

Back 7

-specialized connective tissue
-anchors teeth to alv bone proper
-cushions forces of mastication
-acts as sensory receptor
--assists in normal jaw positioning
--prevents excessive masticatory forces

Front 8

Perio lig:
primary cells
primary fibrous element

Back 8

-fibroblasts
-collagen Type I

Front 9

Sharpey's fibers

Back 9

-portion of collagen bundle that inserts into bone or cementum

Front 10

PDL collagen fibers are constantly ___________

Back 10

-broken down and reformed

Front 11

oxytalan fibers (2)

Back 11

-elastin-like fibers
-present in PDL

Front 12

PDL: cells (6)

Back 12

-fibroblasts
-macrophages
-undiff mesenchymal cells
-cementoblasts
-osteoblasts/osteoclasts
-remnants of root sheath (-> epithelial cell rests)

Front 13

PDL: alveolodental group
def
func
components(4)

Back 13

-insert into bone, cementum
-withstand intrusive, extrusive, lateral movements (during mastication)

-alveolar crest fibers
-horizontal fibers
-oblique fibers
-apical fibers

Front 14

PDL: principal fiber grps (4)

Back 14

-alveolodental group: inserts into bone/cementum
-interradicular fibers: into interradicular bone btw teeth
-transeptal/interdental fibers: btw adjacent teeth. maintain tooth-tooth contact
-gingival grp: maintain tight "cuff" of gingiva

Front 15

PDL: gingival grp (4)

Back 15

-circular fibers
-dentogingival fibers
-alveologingival fibers
-dentoperiosteal fibers

Front 16

alveolar bone is entirely dependent on _____

Back 16

-presence of teeth

Front 17

Alv bone proper:
bundle bone
cribiform plate
lamina dura

Back 17

-insertion of Sharpey's fibers
-perforations in wall of socket for vessels/nerves suplying PDL
-thin layer of compact bone seen on radiographs

Front 18

layers of the dentogingival junction (3)

Back 18

-keratinized gingival epithelium
-gingival sulcus: groove of nonkeratinized epith
-junctional epith: specialized collar of epith

Front 19

junctional epith (3, incl aka)

Back 19

-aka attached epith
-forms modified basement membrane
-provides attachment of gingiva to tooth

Front 20

what is different about the modified BM of junc epith? (3)

Back 20

-no collagen IV
-has sublamina lucid
-has enamel cuticle

Front 21

why is junctional epith "leaky"
why important

what is relatively impermeable

Back 21

-fewer desmosomes
-neutrophils/fluid can enter thru gingival sulcus
-bacteria metabolites can also penetrate into underlying conn tissue

-sulcular epith

Front 22

general functions:
gingiva
jenc epith
PDL
cementum

Back 22

-withstand abrasion
-tight seal btw oral mucosa, underlying conn tissue
-cushions teeth, gives sensory feedback
-form joint btw tooth and bone

Front 23

cementum: mineral cont

Back 23

-50-65%
-variable b/c of PDL fibers/presence of cementocytes

Front 24

primary cementum (3)

Back 24

-bonds remaining cementum to dentin
-usually acellular
-forms "hyaline layer" -> interdigitating colalgen fibers in highly mineralized zone

Front 25

hyaline layer: origin

Back 25

-uncertain
-maybe cells of root sheath

Front 26

2ndary cementum (4)

Back 26

-acellular in cervical 1/3-1/2
-cellular in apical 1/2-1/3
-adapt root to changes in socket
-provide anchorage via insertion of PDL fibers

Front 27

fibrillar cementum (2)

afibrillar cementum (2)

Back 27

-collagen fibers present
-majority of cementum

-mineralized ground substance
-small, extends a tiny bit onto enamel surface at cervix of tooth

Front 28

epithelial cell rests (2)

Back 28

-cell type in PDL
-remnants of root sheath

Front 29

Alveolar crest fibers (2)

Back 29

-alveolodental grp
-cervix -> crest of alv ridge

Front 30

horizontal fibers (2)

Back 30

-alveolodental grp
-cervical region of root

Front 31

oblique fibers (1)

Back 31

-majority alveolodental grp

Front 32

apical fibers (2)

Back 32

-alveolodental grp
-floor of socket -> apical end of root

Front 33

interradicular fibers (2)

Back 33

-alveolodental grp
-extend across and into interradicular bone of multirooted teeth

Front 34

circular fibers (3)

Back 34

-gingival grp
-encircles cerv region of tooth, like "spandex waist"
-does not insert into anything

Front 35

dentogingival fibers (2)

Back 35

-gingival grp
-cement near cervix -> lamina propria of attached gingiva

Front 36

alveologingival fibers (2)

Back 36

-gingival grp
-alveolar crest -> lamina propria (of attached gingiva)

Front 37

mucoperiosteum

Back 37

-attached gingiva is bound directly to periosteum of alveolar bone

Front 38

fluid in gingival sulcus (3)

Back 38

-sulcular (crevicular)
-derived from underlying conn tissue
-inhibits bacteria

Front 39

dental pulp (3)

Back 39

-unmineralized oral tissue
composed of:
-loose conn tissue
-vascular, lymph, nervous elements

Front 40

where do vessels and nerves enter/exit tooth

Back 40

-through apical foramen

Front 41

dentin/pulp both derived from

Back 41

-dental papilla

Front 42

pulp: primary function

2ndary functions of pulp (4)

Back 42

-provide vitality to tooth

-inductive: interacts during formation
-formative: odontoblasts form dentin
-protective: reactive/reparative/sclerotic dentin
-sensory

Front 43

4 regions of pulp

Back 43

-odontogenic zone (diffs into odontoblasts)
-cell-free zone (of Weil)
-cell rich zone (w/ fibroblasts, stem cells). Incl subodontoblastic nerve plexus
-pulp core (w/ large vessels, nerves)

Front 44

Modalities (2)

Back 44

-symp: reg blood flow
-afferent (nociceptors) btw odontoblasts, like free nerve endings

Front 45

hydrodynamic theory?? (2)

Back 45

-small myelinated fibers are stim'd by fluid movement in dentinal tubules (sharp pain)
-injury, inflammation lead to unmyelinated C fibers (dull ache)

Front 46

Pulp: changes w/ age (3)

Back 46

-lower # of cells, more fibrous matrix
-pulp chamber becomes smaller (b/c of 2ndary dentin)
-pulp stones, and diffuse calcification