Periodontal Anatomy - part 2 Flashcards
What two areas does the attached gingiva attach?
- periosteum
2. tooth - cementum and enamel via JE
During tooth eruption, all cells of the ___ ___ epithelium are replaced by junctional epithelium.
reduced enamel epithelium
T/F. After tooth eruption, the cells of the oral epithelium possess the ability to differentiate into cells of junctional epithelium.
True. If the free gingiva is excised after tooth eruptions, a new JE will develop from the oral epithelium.
Where is the JE widest? thinnest?
widest in its coronal portion (15-20 cells)
thinnest towards CEJ (3-4 cells)
The size of the JE cells is ___ (smaller/larger) than OE. The intracellular space of JE is ___ (thinner/wider) than OE.
larger; wider
Who has more desmosomes, JE or OE?
OE
Does the JE have the potential to keratinize?
yes, this is a protective mechanism
T/F. JE is in contact with the tooth. It does not physically attach to it.
False, JE IS physically attacted to the tooth
In a child, the JE sit ___ (low/high) on the tooth and there is a ___ (smaller/larger) sulci. The probe depths are generally ___ (consistent/inconsistent).
high; smaller; inconsistent
In an adult, where does the JE sit?
coronal (1mm) to CEJ or at the CEJ
In a diseased patient, the JE is not loss, but migrates downward. This is known as ___ ___.
attachment loss.
When does periodontitis occur?
when the JE migrates apically down the root surface. A viable JE is necessary for pocket formation.
A HIV postitive patient presents with loss of JE and exposed bone. Because the JE cells have died, no pocketing can be performed. This patient is at risk for developing osteomyelitis of the bone. What condition does he have?
Necrotizing ulcerative periodontitis (NUP)
Your probe contacts the bone at 3mm below the CEJ, but there is no recession of the gingiva, which is located 3mm above the CEJ. How would you describe the attachment loss, recession and probe depth?
attachment loss - 3mm
recession - negative because gingiva coronal to CEJ
probe depth - 6mm
The margin of the gingiva is at the CEJ and you measure a probe depth of 6mm. What does this tell you about attachment loss?
it is also 6mm. It is recorded from the CEJ to the level of bone loss.
Your probe measures bone loss at 9mm below the CEJ. You notice the gingiva is apical to the CEJ at 3mm. Describe the attachment loss, recession and probe depth?
attachment loss - 9mm
recession - true because gingiva is apical to the CEJ
probe depth - 6mm
What is another name for the connective tissue of the gingiva?
lamina propria
Of the 6 cells found in the lamina propria, which cell synthesizes CT matrix and fibers?
fibroblast
Which lamina propria cell produces vasoactive substances which can affect the function of the microvascular system and control the flow of blood through the tissue?
mast cells
In addition to fibroblast and mast cells, what other cells are found in the lamina propria?
macrophages, neutrophillic granulocytes, lymphocytes, plasma cells
Which cells produce CT collagen fibers?
fibroblast, cementoblasts, osteoblasts
What predominates in the gingival tissue?
collagen fibers
Which type of fiber is numerous in the tissue adjacent to the basement membrane and blood vessels?
reticulin fibers
___ fibers are scarce in the gingiva but numerous in the ___ ___. They run ___ (parallel/perpendicular) to the long axis of the tooth.
oxytalan; periodontal ligament; parallel
___ fibers in the CT of the gingiva and periodontal ligament are only present in association with blood vessels.
elastic
___ fibers are fiber bundles that run in the free gingiva and encircle the tooth in a cuff- or ring-like fashion.
circular
Dento-___ fibers are embedded in the cementum of the ___-___ portion of the root and project from the cementum in a ___-like configuration out into the free gingiva of facial, lingual and interproximal surfaces.
gingival; supra-alveolar; fan
Which fibers run from supracrestal cementum into attached gingiva?
dento-periosteal fibers
Which fibers run from tooth to tooth across the interdental septum and are embedded in the cementum of adjacent teeth?
trans-septal fibers
What structure is a richly vascular and cellular CT surrounding the roots and joining cementum and alveolar bone?
periodontal ligament
The periodontal ligament permits ___ to be distributed and is essential for the tooth ___.
forces; mobility
What are the four types of fibers of the PDL?
- alveolar crest fibers
- horizontal fibers
- oblique fibers
- apical fibers
___ cells are aligned along the principal fibers, ___ cells line the surface of the cementum, and ___ cells line the bone surface.
fibroblasts; cementoblasts; osteoblasts
What cells can you find in clusters in the PDL that represent remnants of Hertwig’s epithelial root sheath?
epithelial cell rests of Mallassez
The ___ is a mineralized tissue that covers the root surface and occasionally, small portions of the crown of the teeth.
cementum
Matching: Do cementum have or do the following?
- blood vessels
- lymph vessels
- innervation
- phyisologic resorption/remodeling
- continued deposition throughout life
- collagen fibers embedded in organic matrix
- high mineral content mainly of HA
A. yes
B. no
- B
- B
- B
- B
- A
- A
- A
___ cemental fibers are produced by ___ and oriented parallel to the root.
Intrinsic; cementoblast
Extrinsic cemental fibers contain ___ fibers and are produced by PDL ___.
Sharpey’s; fibroblasts
Match: Which is found where?
- acellular, extrinsic fiber cementum
- cellular, mixed stratified cementum
- cellular, intrinsic fiber cementum
A. in resorption lacunae
B. apical third of the root and in the furcations
C. coronal or middle portion of the root
- C
- B
- A
T/F. The cementum stays the same thickness throughout life.
False, its thickness increases by gradual apposition throughout life.
Cementum thickness in the cervical part of the root is ___-___um and ___-___um in the apical portion.
20-50; 150-250
T/F. Alveolar bone is formed both by cells from the dental follicle and cells independent of tooth development.
True.
The walls of the sockets are lined by ___ bone and the area between the sockets and between the compact jaw bone walls is occupied by ___ bone.
cortical; cancellous
what can be found in the bone marrow?
- adipocytes
- vascular structures
- undifferentiated mesenchymal cells
what causes the alveolar bone to remodel?
forces and tooth movement
___ produce bone matrix (osteoid) consisting of collagen fibers, glycoproteins and proteoglycans.
Osteoblasts
___ undergoes mineralization by the deposition of minerals (calcium and phosphate).
osteoid
Review images of blood supply to the gingiva and periodontal tissues, the lymphatic system, and the nerves.
no seriously, do it right now
Explain extravascular circulation.
circulation through which nutrients and other substances are carried to the individual cells and metabolic waste products are removed from the tissue.
What occurs at the arterial end?
the hydraulic pressure is greater than the osmotic pressure in tissues therefore substances will go from the blood vessels into the extravascular space.
What occurs on the venous end?
The hydraulic pressure is decreased and substances travel between the extravascular space to the blood vessels.
