WEEK 7 - ALVEOLAR BONE AND PERIODONTAL LIGAMENT

Question 1

what is the alveolar bone?

Answer 1

the bone of the jaws containing the sockets

Question 2

what does the alveolar bones presence depend on?

Answer 2

teeth

Question 3

what is the remaining bony part of the mandible and maxillae called?

Answer 3

basal bone

Question 4

what are the three layers of alveolar bone?

Answer 4

compact, cancellous, labial and lingual cortical plates

Question 5

what is the interdental septum?

Answer 5

alveolar bone found between two teeth

Question 6

what is the inter-radicular septum?

Answer 6

alveolar bone between the roots of a multi-rooted tooth

Question 7

what is the significance of the inter-dental septum and the inter-radicular septum?

Answer 7

they contain the nutrients canals which carries blood vessels and nerves

Question 8

in anterior teeth, the lingual plate is __________ than the labial plate

Answer 8

thicker

Question 9

in lower posterior teeth, the lingual plate is _________ than the buccal plate

Answer 9

thinner

Question 10

in upper posterior teeth, the lingual plate is _________ than the buccal plate

Answer 10

thicker

Question 11

why is the alveolar bone sometimes called the bundle bone?

Answer 11

the bundles of the principal fibres of the periodontal ligament are embedded

Question 12

how does the alveolar bone appear radiographically?

Answer 12

radioopaque

Question 13

what is the clincal consideration of cortical plates?

Answer 13

the thickness determines the direction of the initial movement during extraction

Question 14

each tooth is attached to and separated by the adjacent alveolar bone by a heavy collagenous supporting structure called the

Answer 14

periodontal ligament

Question 15

what is the PDL composed of?

Answer 15

a complex vascular and highly cellular connective tissue. Collagen fibres

Question 16

what are the functions of the PDL?

Answer 16

maintains tooth position
resists occlusal loading
maintains and repairs alveolar bone and cementum

Question 17

how does the PDL repair?

Answer 17

it contains stem cells

Question 18

the periodontal ligament is formed by a variety of cells. The types of cells are

Answer 18

synthetic, resorptive, progenitor, defensive, epithelial

Question 19

what are the types of synthetic cells that make up the PDL

Answer 19

fibroblasts, osteoblats, cementoblasts

Question 20

what are the types of resorptive cells that make up the PDL

Answer 20

osteoclasts, cementoclasts

Question 21

what type of progenitor cell makes up the PDL

Answer 21

undifferentiated mesenchymal

Question 22

what types of defensive cells make up the PDL

Answer 22

macrophages, lymphocytes, and mast cells

Question 23

what types of epithelial cells make up the PDL

Answer 23

epithelial rests of mallasez

Question 24

what intercellular substances make up the PDL

Answer 24

fibres, ground substance, blood vessels, nerves, lymphatics

Question 25

the fibres in the periodontal ligament are mostly ______ and they are divided into

Answer 25

collagen. principal, accessory, oxytalan

Question 26

the most important element of the PDL are the

Answer 26

principal fibres

Question 27

the terminal portions of the principal fibres that are incerted into cementum and bone are

Answer 27

sharpey fibres

Question 28

based on their location and orientation, the principal fibres are grouped into

Answer 28

gingival, interdental, and alveodental

Question 29

principal gingival fibers form a

Answer 29

rigid cuff around the tooth

Question 30

principal interdental fibres connect

Answer 30

two adjacent teeth running from the cementum of one tooth to the cementum of the next

Question 31

what are the types of principal fibres?

Answer 31

alveodental ligament, accessory, and oxytalan fibres

Question 32

what are the types of principal alveodental ligament fibres

Answer 32

alveolar crest group, horizontal group, oblique fibres, apical fibres, interradicular fibres

Question 33

what is the alveolar crest group?

Answer 33

radiates from the crest of the alveolar process to the cervical part of the cementum

Question 34

what is the horizontal group?

Answer 34

run from the cementum in a perpendicular direction to attach to bone

Question 35

what is the oblique fibres?

Answer 35

most predominant group

Question 36

what is apical fibres?

Answer 36

cementum to bone in apical regions

Question 37

what are interradicular fibres?

Answer 37

radiate from cementum to bone in furcation regions

Question 38

what are transeptal fibres?

Answer 38

gingival and periodontal fibres that go from one cementum to the next with no attachment to bone.

Question 39

what are accessory principal fibres?

Answer 39

collagenous fibres that run from bone to ceentum in different planes, found in the region of horizontal group

Question 40

what are oxytalan principal fibres?

Answer 40

immature elastic fibres. one is embedden in bone or cementum and the other in the wall of a blood vessel to support them during mastication

Question 41

where is the arterial supply of the periodontal ligament derived from?

Answer 41

gingival, intra-alveolar, and apical vessels

Question 42

where does the nerve supply of periodontal ligament come from?

Answer 42

inferior or superior dental nerves

Question 43

what happens to the PDL with age?

Answer 43

a decrease in vascularity, cellularity, and thickness. they can also form cementicles

Question 44

what are the clinical considerations of the PDL regarding tooth avulsion

Answer 44

a tooth that is replaced within half an hour after can be re-implanted due to regeneration and revascularization of the PDL

Question 45

what are the clinical considerations of the PDL regarding implants

Answer 45

implants lack periodontal fibres so they may fail under excessive load.