Theory: periodontal ligament

the periodontal ligament is the space between ___ and ____ (connects the two)

cementum, alveolar bone

the periodontal ligament is ___ in width and surrounds the ___

0.25mm, root of the tooth

the periodontal ligament is made of

collagen fibers, connective tissue, multiple cellular elements, cementicles

the fibers are the ___ element of the PDL

most important

the fibers of the PDL are __ fibers

collagen

the fibers of the PDl are arranged in __ and they follow a __ course

bundles, wavy

the fibers of the PDL are attached to into

cementum and bone

at the insertion point, the fibers of the PDL are called

sharpey's fibers

fibers of the PDl maintain their structure by

stimulation

a tooth not under function will have a __ PDL

thin

a tooth under normal function will have a __ PDL

thicker

a tooth under more stress will have ___ PDL

even thicker

occlusal trauma is when forces exceed what the ___ can withstand

fibers

the loose connective tissue is in between ___ and is the location of a lot of

fibers, cellular elements

what are the cellular elements of the PDl

fibroblast, cementoblast, osteoblast, osteoclast, mesenchymal cells, tissue macrophages, epithelial rests of malassez

the fibroblast of the PDL are the most ____ cells in the CT

numerous

the ___ are formative cells responsible for manufacturing new PDL fibers

fibroblasts

cementoblasts are formative cells responsible for

laying down new cementum

osteoblasts are the formative cells responsible for

laying down new bone

osteoclasts function in the

resorption of bone

mesenchymal cells can be modified into __, __ or __ depending on the function needed to be performed

fibroblasts, cementoblasts, osteoblasts

tissue macrophages of the PDL are __ cells

defense

tissue macrophages of the PDL are able to engulf toxic bacterial products by

phagocytosis

the epithelial rests of malassez are isolated clusters of

epilthelial cells

the epithelial rests of malassez are remnants from

hertwig's epithelial root sheath

hertwigs epithelial root sheath is responsible for

shaping roots and dentin during embryonic period

the epithelial rests of malassez are important pathologically and can proliferate if stimulated and form

cysts

cementicles are tiny __ structures

calcified

cementicles can attach to the __ or lie free in the __

cementum, PDL

cementicles are only important clinically if

exposed

blood vessels enter the PDl from the apical region and extend to the

gingiva

the greatest source of blood for the PDL comes from vessels that penetrate through channels in the

interdental alveolar bone

the blood vessels enter the PDL from vessels locate in the __ of the gingiva

laminate propria (CT)

lymphatics follow the same pathway as

blood vessels

nerve fibers of the PDL transmit the sensations of

pressure, pain and proprioception

the innervation of the PDL follows the same course as the

blood vessels

the nerves enter the PDL from the same three pathways as the

blood vessels

principal fibers are collagen fibers arranged into groups to resist

mechanical forces

the principle fiber group is within the PDL and is a group of __ fibers

5

the principle fibers include

alveolar crest, horizontal, oblique, apical, interradicular

the alveolar crest fibers extend obliquely from the cementum just beneath the ____ to the alveolar bone

epithelial attachment

the alveolar crest is the __ largest fiber group

fourth

the functions of the alveolar crest is to

counterbalance coronal movements and resists horizontal (lateral)movements

horizontal fibers extend at ___ angles to the long axis of the tooth from cementum to the bone

right

the horizontal fibers are the __ largest group

3rd

the function of horizontal fibers is similar to

alveolar crest fibers

oblique fibers are the __ fiber group

major (2/3 of all fibers)

oblique fibers extend from the cementum to the bone at an __ angle

oblique

the attachment of the oblique fibers is more coronal on the bone than on the

cementum

the function of the oblique fibers is to resist ___ forces applied along the long axis of the tooth

vertical

apical fibers are located at the

root apex

the apical fibers radiate apically from cementum to

bone

the apical fibers are the __ largest fiber group

second

the function of apical fibers are to maintain the tooth __

in the socket

the interradicular fibers are only present around

multi-rooted teeth

the interradicular fibers extend from the crest of the bone to the

furcation

the interradicular fibers provide the same function as the

apical fibers

the formative functions of the PDL

fibroblasts, cementoblasts, osteoblasts

functions of the PDl

formative, supportive, protective, sensory, nutritive

supportive functions of the PDL

maintain tooth within bone, fibers support position of junctional epithelium

protective functions of PDL

resist mechanical forces, act as soft tissue casing to protect blood vessels and nerves from injury, contains defense cells

sensory functions of PDL

nerves provide the sensations of pain, pressure, proprioception

sensation of the PDL is supplied by the

trigeminal nerve (CN V)

the nutritive function of the PDL

nutrients supplied to cementum, bone, and gingiva via the blood vessels

blood supply of the PDL comes from the ___ alveolar arteries

inferior and superior