Exam 1; Junctional Epithelium Flashcards
Where does the junctional epithelium originate from during and after tooth eruption
during = reduced dental epithelium after = the cells of the oral (sulcular) epithelium possess the ability to differentiate into the cells of the JE
Where is the JE widest?
in the coronal portion (15-20 cell layers)
thin towards the CEJ (3-4 cells)
Where is the JE located
at or just below the CEJ
What is the relative size of the cells and interstitial space of the JE compared to the OE
relatively large
What is the number of desmosomes of the JE compared to the OE
JE < OE
True or False
JE has the potential to keratinize
True
True or False
JE is physically attached to the tooth, not simply in contact with it
True
Apical movement of junctional epithelium in health and disease changes how
loses attachment position, not attachment itself
This occurs when the junctional epithelium migrates apically down root surface
periodontitis
This is necessary for pocket formation
viable junctional epithelium
Necrosis of JE is seen in what (the cells die)
necrotizing ulcerative periodontitis
What are the 6 cells that compose the gingival lamina propria
fibroblasts mast cells macrophages neutrophilic granulocytes lymphocytes plasma cells
What are the four fibers of the lamina propria
collagen
reticulin
oxytalan
elastic
This fiber has characteristic cross-bonding, the most abundant, and is produced by fibroblasts, cementoblasts, and osteoblast
collagen
This fiber is numerous adjacent to basement membrane and around blood vessels
reticulin
This fiber is mostly in the PDL and runs parallel to the long axis of the tooth
oxytalan
This fiber is mostly around blood vessels
elastic
These reinforce the gingiva, provide resilience and tone, and maintain the architectural form and integrity
gingival fibers
What are the four gingival fibers
circular fibers
dentogingival
dentoperiosteal
transeptal
This gingival fiber encircles the tooth like a cuff
circular fibers
This gingival fiber fans out from supra-crestal cementum onto free gingiva
dentogingival fibers
This gingival fiber runs from supracrestal cementum into attached gingiva
dentoperiosteal fibers
This gingival fiber runs from tooth to tooth (embedded in cementum)
transeptal
This is richly vascular and cellular CT surrounding the roots and joining cementum and alveolar bone
periodontal ligament
How is the PDL depicted radiographically
the space between lamina dura and root surface
What is width of the PDL
0.25mm
What is the function of the PDL
permits forces to be distributed
essential for tooth mobility
These cells of the PDL are aligned along the principal fibers
fibroblasts
These cells of the PDL line the bone surface
osteoblasts
These cells of the PDL line the cemental surface
cementoblasts
These cells of the PDL are multinucleate and create a ruffled surface of bone epithelial cells
osteoclasts
These are remnants of the Hertwig’s epithelial root sheath
epithelial rests of Mallassez
This is the mineralized tissue covering root surface and occasionally, small portions of the crown of the teeth
cementum
What are the four differences between cementum and bone
no blood vessels
no lymph vessles
no innervation
no physiologic resorption/remodeling
What three things characterize cementum
continuing deposition throughout life
collagen fibers embedded in organic matrix
high mineral content (65%); mainly HA
These cemental fibers are produced by cementoblasts; composed of fibers oriented parallel to root
intrinsic
These cemental fibers are also known as Sharpey’s fibers and are produced by PDL fibers
extrinsic
These cemental fibers are located coronal or the middle portion of the root
acellular, extrinsic fiber cementum
These cemental fibers are in the apical third of the root and in furcation
cellular, mixed stratified cementum
These cemental fibers in resorption lacunae
cellular, intrinsic fiber cementum
Cementum thickness increases when
gradually throughout life
cervical portion = 20-30µm
apical portion = 150-250µm
Alveolar bone consists of bone formed by what sources
cells from the dental follicle
cells independently of tooth development
In alveolar bone, the osteoblasts produce what
bone matrix (osteoid) consisting of collagen fibers, glycoproteins, and proteoglycans
In alveolar bone, osteoid undergoes what
mineralization by the deposition of minerals (calcium and phosphate)
What vessels supply the gingiva
supraperiosteal vessels
What vessels supply the periodontal tisssues
dental artery
superior/inferior alveolar
intraseptal
What are the four lymph nodes associated with the gingiva/PD tissues
submental
deep cervical
submandibular
jugulodigastric
What are some nerves of the periodontium
end branches of the trigeminal
