Gingival Fibers and PDL

Question 1

what are the functions of the gingival fiber ligament

Answer 1

-stabilizes the gingiva by providing rigidity and density to the marginal gingiva
- acts as a periosteum for the interproximal crestal alveolar bone
- provide one half of the biological width
-acts as a protective barrier for the crestal alveolar bone against the spread of gingival inflammation
-inhibit the apical migration of the junctional epithelium

Question 2

what are the GFL fiber groups

Answer 2

dentogingival, dentoperiosteal, alveologingival ,circular, transseptal, semicricular, transgingival

Question 3

how many semicircular GFL fibers groups, transspetal, and transginigval are there

Answer 3

9,7, and 3

Question 4

what is the function of transseptal fiber groups

Answer 4

resist tooth separation

Question 5

what is the function of dentogingival fiber groups

Answer 5

resists gingival displacement

Question 6

what is the function of alveogingival fiber groups

Answer 6

resist gingival displacement

Question 7

what is the function of circumferential fiber groups

Answer 7

resist gingival displacement

Question 8

what is the function of semicircular fiber groups

Answer 8

resist gingival displacement and tooth separation

Question 9

what is biological width

Answer 9

area of junctional epithelium and gingival fiber ligaments attached to the root of a tooth

Question 10

how big is the junctional epithelium, gingival fiber ligaments

Answer 10

0.98 - junctional epithelium
1.02 - gingival fiber ligaments

Question 11

where is the biological width located

Answer 11

extends from crest of gingival to crest of alveolar bone

Question 12

what happens if the biological width is violated

Answer 12

chronic inflammation will occur and result in induced loss of supporting alveolar bone with formation of a diseased periodontal pocket

Question 13

when does violation of biological width occur

Answer 13

with incorrect placement of crowns

Question 14

what are the symptoms of violation of biological wdith

Answer 14

itchy and bleeding gums, chronic irritation/inflammation

Question 15

how do you fix violation of biological width

Answer 15

crown lengthening, change height of alveolar crest to keep 2 mm separation

Question 16

what does the periodontal ligament contain

Answer 16

co-fibers of collagen that interlock together

Question 17

what are the functions of the peridodontal ligament

Answer 17

-supportive
- regeneration
-nutritional
-sensory
-protective

Question 18

what are the dental follicle zones and what do they give rise to

Answer 18

-peripheral zone - alveolar bone proper
- intermediate zone - PDL
- proximal zone - cementoblasts

Question 19

what is the PDL derived from

Answer 19

neural crest (ectomesenchymal cells) in the intermediate zone of the dental follicle

Question 20

periodontal fibers form as ____

Answer 20

the tooth grows

Question 21

what do PDL fiber groups do

Answer 21

contract and function in the eruption of the tooth

Question 22

what are PDL fibers designed to resist

Answer 22

rotational/torque-like forces on the tooth

Question 23

what are sharpey’s fibers

Answer 23

collagen fibers from the alveolar bone and cementum that embed into cementum

Question 24

what cells are in the PDL

Answer 24

-fibroblasts
-osteoblasts
-cementoblasts
-macrophages
-undifferentiated mesenchymal cells
-endothelial cells
-epithelial cells

Question 25

what do apical fibers do

Answer 25

resist vertical force

Question 26

what do oblique fibers do

Answer 26

resists intrusive/masticatory force

Question 27

what do horizontal fibers do

Answer 27

resist horizontal and tipping force

Question 28

what do alveolar crest fibers do

Answer 28

resist vertical force

Question 29

what do interradicular fibers do

Answer 29

resist vertical and lateral force

Question 30

what is orthodontic relapse

Answer 30

after ortho treatment, retainers are given due to PDFs memory

Question 31

what is done to limit orthodontic relapse from occurring

Answer 31

transseptal fibers and semicircular fibers are cut

Question 32

what are interstital spaces

Answer 32

source of mesenchymal cells that can differentiate into cementoblasts, osteoblasts, and fibroblasts

Question 33

what do cementoblasts do

Answer 33

regeneration and repair of cementum following injury

Question 34

what do osteoblasts do

Answer 34

function in regeneration and repair of bone following disease or orthodontic therapy of alveolar bone

Question 35

what do fibroblasts do

Answer 35

involved in collagen production and physiological collagen degradation

Question 36

what is ankylosis

Answer 36

reparative response to injury

Question 37

what happens in ankylosis

Answer 37

fusion of cementum with the alveolar bone without intervening the PDL

Question 38

what happens in singificant injury in akylosis

Answer 38

cells responding are from the supporting alveolar bone, results in ankylosis and loss of PDL

Question 39

what happens in slight injury in ankylosis

Answer 39

cells responding are from the PDL will regenerate all tissues involved and PDL will be restored

Question 40

what are the steps in wound healing

Answer 40

-undifferentiated cells migrate into the area as macrophages and PMNs cause inflammatory response and remove damaged tissues - fibroblasts and or osteoblasts replace the damaged tissue - a mast cell response is usually present in which heparin and histamine are released. this inflammatory response helps the necessary cells reach their target

Question 41

what is guided tissue regeneration

Answer 41

surgical technique of regenerating the periodontal attachment apparatus on periodontally involved teeth which uses the differentiation of mesenchymal cells in the interstitial spaces of the PDL and narrow spaces of the adjacent alveolar bone

Question 42

what does guided tissue regeneration use

Answer 42

a membrane to help block epithelial cells from growing down into the defect

Question 43

what are epithelial rests of malassez

Answer 43

remains of hertwigs rooth sheath, duct like apperance with unknown function

Question 44

where are epithelial rests of malassez found

Answer 44

apical areas of adolescent teeth

Question 45

when do lateral periodontal cysts occur

Answer 45

when rests of malassez are activated

Question 46

is tx of lateral periodontal cysts necessary

Answer 46

yes

Question 47

what are epithelial rests of serres

Answer 47

remains of the dental lamina

Question 48

what is a gingival cyst derived from

Answer 48

odontogenic epithelium located in the CT of the gingiva

Question 49

what are epithelial rests of serres thought to be connected to

Answer 49

gingival keratocyst/odontogenic keratocyst

Question 50

what does orthodontic movement result from

Answer 50

compression of the PDL on the side of the root corresponding to the direction of movement

Question 51

what happens to the PDL in direction of tooth movement

Answer 51

compression of the PDL results in loss of principle fiber orientation and resorption of adjacent bone. fibroblasts and osteoclasts eating things

Question 52

what happens to the PDL in movement in the direction opposite tooth movement

Answer 52

stretching/tension of the PDL principle fibers, controlled tension results in bone apposition -osteoblasts laying down bone

Question 53

what is trauma from occlusion

Answer 53

extensive functional stresses placed on a tooth by an antagonist that exceeds the limits of physiological adaptation

Question 54

what does trauma from occlusion result in

Answer 54

resportion of alveolar bone parallel to the long axis of the root -a PDL that is wider than normal average width -tooth mobility

Question 55

what is the tx for trauma from occlusion

Answer 55

re-establishing occlusion by fixing crown

Question 56

what is disuse atrophy from

Answer 56

a tooth with no occlusal antagonist

Question 57

what does disuse atrophy result in

Answer 57

-significant decrease in density of bony trabeculae - decreased width of PDL - loss of orientation of the principle fibers of the PDL - increased volume of the bone marrow spaces

Question 58

what is an ameloblastoma

Answer 58

aggressive benign tumor derived from odontogenic epithelium that exhibits a radiolucent, multilocular radiographic appearance