Junctional Epithelium Flashcards
During tooth eruption, the junctional epithelium is made up of ________ epithelium.
Reduced Dental Epithelium
After tooth eruption, cells of the _______ possess the ability to differentiate into cells of the junctional epithelium.
oral epithelium
At which location is the junctional epithelium widest?
in the coronal region (15-20 cell layers thick)
At which location is the junctional epithelium most narrow?
in the CEJ region (3-4 cell layers thick)
True or False: Junctional Epithelium is continuously renewed.
True
True or False: Turnover rate for oral epithelium is faster than junctional epithelium.
False: JE is faster
Compared to oral epithelium, the junctional epithelium has larger ____ and larger ______.
cells and intercellular space
The junctional epithelium has fewer _____ than the oral epithelium.
desmosomes
What is the significance in different numbers of desmosomes between JE and OE?
Fewer desmosomes means larger gaps in the JE. Neutrophils must be able to enter/leave through the JE
Which type of epithelium has the ability to keratinize, JE or OE?
Junctional Epithelium
True or False: The junctional epithelium is simply in contact with the tooth, not physically attached.
False; JE is attached
Why is it important to never probe sulcular pockets in children?
the JE sits much higher in children because passive eruption has not occured. The sulcus is much more shallow and sensitive to forced attachment loss.
What is “attachment loss?”
apical movement of the junctional epithelium down the root surface, away from the CEJ; it is not a physical loss of epithelium but rather a loss of position
True or False: Viable functional epithelium is necessary for pocket formation.
True
What happens in Necrotizing Ulcerative Periodontitis (NUP)?
Junctional epithelial cells DIE and bone is exposed; there is NO POCKETING
Clinical attachment loss is equal to ______ + ________.
Pocket depth + gingival recession
Is gingival recession recorded as a positive or negative number?
Positive
If a patient has a pocket depth of 10mm, but the bottom of the pocket is only 7mm below the CEJ: how much recession do they have?
+3mm
If a patient has a pocket depth of 6mm, but the free gingival margin is 3mm coronal to the CEJ: how much attachment loss do they have? Is this normal/what is happening?
Clinical Attachment Loss (CAL) = recession +pocket depth
-3mm + 6mm = 3 mm AL
This is pseudopocketing
If a patient has 3mm of recession and a 6mm pocket depth, what is their CAL?
9mm (pocket depth + recession)
Gingival Connective Tissue (lamina propria) matrix and fibers are synthesized by _______.
Fibroblasts
Which cells of the lamina propria are vasoactive?
Mast Cells
Which cells of the lamina propria are synthesizing and phagocytic?
Macrophages
In addition to fibroblasts, mast cells, and macrophages; which cells types are present in the lamina propria (gingival connective tissue)?
Neutrophilic Granulocytes
Lymphocytes
Plasma Cells
Which four fiber types are prevalent in the lamina propria (gingival CT)?
- collagen
- reticulin
- ocytalan
- elastic
* C.O.R.E of the gingiva*
Which fiber type is most abundant in the gingival connective tissue (lamina propria)?
Collagen
What is characteristic of collagen in the lamina propria?
Cross-banding
Collagen is produced by _______, ________, and ______.
Fibroblasts
Osteoblasts
Cementoblasts
Which two fiber types of the lamina propria are found around blood vessels?
Reticulin and elastic fibers
Which fiber type of the lamina propria is found mostly in the PDL?
Oxytalan
What three critical roles do gingival fibers play in the periodontium?
- reinforce the gingiva
- provide resilience and tone
- maintain architectural form and integrity
Name four important gingival fiber types.
- Circular
- Dentogingival
- Dentoperiosteal
- Transseptal
Which gingival fiber type encircles the tooth like a cuff?
Circular
Which gingival fiber type fans out from supracrestal cementum into free gingiva?
Dentogingival
Which gingival fiber type runs from supracrestal cementum into attached gingiva?
Dentoperiosteal
Which gingival fiber type runs from tooth to tooth (embedded in cementum)?
Transseptal
What is the difference between dentoperiosteal and dentogingival?
both run from supracrestal cementum:
gingival–>free gingiva (more coronally fanned out)
periosteal–>attached gingiva (more apical)
Definition: Richly vascular and cellular connective tissue surrounding the roots and joining cementum and alveolar bone.
Periodontal Ligament (PDL)
Radiographically, the PDL is the space between the ________ (alveolar bone proper) and the root surface.
lamina dura
How wide is the PDL?
~0.25mm
What is the functional importance of the periodontal ligament?
permits forces to be distributed and is essential for tooth mobility
Name the four fibers of the PDL.
- Alveolar Crest Fibers (ACF)
- Horizontal Fibers (HF)
- Oblique Fibers (OF)
- Apical Fibers (APF)
think “aLoha” (L for ligament)
True or False: There is no structural or compositional difference between differently named fibers of the PDL.
True
Cells of the PDL include _________, osteoblasts, osteoclasts, cementoblasts, epithelial cells, nerve fibers, and ________.
Fibroblasts
Epithelial Rest Cells of Mallassez
What are Epithelial Rest Cells of Mallassez?
Remnants of Hertwig’s epithelial root sheath
What is the mineralized tissue that covers the root surface and portions of the tooth crown?
Cementum
Cementum is similar to bone but differs in which four critical ways?
- No blood vessels
- No lymph vessels
- No innervation
- No physiologic resorption/remodeling
What is the mineral content of cementum?
65%
True or False: Cementum is continually deposited throughout life.
True
Cementum ______ fibers are embedded in ______ matrix.
Collagen
Organic
INTRINSIC cemental fibers are produced by _______ and are oriented _______ to the root.
Cementoblasts
Parallel
IntrInsIc….the “I”s are all parallel
EXTRINSIC cemental fibers are called ________ and are produced by _________.
Sharpey’s Fibers
PDL fibroblasts
What are the three forms of Cemental fibers?
Acellular, extrinsic
Cellular, mixed stratified
Cellular, intrinsic
Which cemental fiber type is found in the coronal or middle portion of the root?
Acellular, extrinsic fibers
Which cemental fiber type is found in the apical third of the root and in furcations?
Cellular, mixed stratified
Which cemental fiber type is found in resorption lacunae?
Cellular, intrinsic
Is cementum thickness greater in the cervical or apical portion of the root?
Apical (150-250 micrometers)
Cervical (20-50 micrometers)
Think about it: what is internal to the cementum? PULP, which takes up less of the thickness as it moves apically
Alveolar bone consists of bone that is formed by cell from which two locations?
cells from the dental follicle
cells independent of tooth development
Alveolar bone is made up of ______ bone and ______ bone.
Cancellous
Cortical
Bone marrow is made up of adipocytes, vascular structures, and undifferentiatied _______ cells.
mesenchymal
True or False: Osteoid (alveolar bone matrix) undergoes mineralization by the deposition of calcium and potassium.
False: calcium and PHOSPHATE
Alveolar bone matrix is produced by _____ .
Osteoblasts
Bone matrix (osteoid) consists of _______fibers, proteoglycans, and _________.
Collagen fibers
glycoproteins
Which dental tissue most closely resembles bone?
cementum
Blood supply to the gingiva is provided by ________ vessels.
Supraperiosteal (terminal branches of multiple vessels of the face)
Blood supply to the periodontal tissues is provided by the dental artery, __________, ________, intra-septal artery, and rami perforantes.
Superior Alveolar a.
Inferior Alveolar a.
Lymphatic drainage of the periodontium is through the _____, deep cervical, _______, and jugulodigastric lymph nodes.
Submental
Submandibular
The periodontium is innervated by end branches of the _____ nerve.
Trigeminal
