Periodontal Ligament Flashcards
Periodontal ligament is what type of articulation/joint?
Syndesmosis
What part of root is the PDL thinnest?
Midroot
Dental tissue which serves as shock absorber?
PDL
A test used to detect inflammation in the periradicular tissues?
Percussion
2 sensations PDL can register?
- Pain
- Pressure
True or false. Periodontal ligament can undergo remodelling?
True
Functions of PDL? (4)
- supportive
- sensory
- homeostasis
- nutritive
Cells of the PDL? (4)
- fibroblast
- cemento/osteoprogenitor cells
- epithelial rest of malassez
- undifferentiated cells/progenitor cells
Principal cells of PDL?
Fibroblasts
Has the highest rate or collagen turnover?
Fibroblast
Cell esponsible for both synthesis and dgradation of collagen?
Fibroblast
Provides strong mechanical attachments between adjacent cells?
Adherens
Specialized focal contacts in ECM formed by the fibroblast?
Fibronexus
Concavities where cementoclast/osteoclast are located?
Howship’s lacunae
True or false. Epithelial rests of Malassez are continuously released?
True
Secreted by the epithelial rest of malassez which regulates PDL?
Epithelial growth factor
Cells of the PDL located around the blood vessels?
Unmyelinated/progenitor cells
3 connective tissue fibers of the PDL.
- Collagen fibers
- Oxytalan
- Elaunin fiber
Type of collagen fibers predominant in PDL? (2)
- Type 1
- Type 3
Principal fiber bundles from cementum to bone?
Dentoalveolar fibers
Type of collagen fiber:
Resist vertical and intrusive forces? (2)
- Alveolar crest
- Oblique fibers
Type of collagen fiber:
Anchors the tooth to the alveolus?
Alveolar crest fibers
Type of collagen fiber:
Resist lateral pressure applied to tooth crown?
Horizontal fibers
Type of collagen fiber:
Prevents vestibulooral tipping?
Apical fibers
Type of collagen fiber:
Resist tipping and torque?
Interradicular fibers
True or false. Fiber insertions are wider in cementum than in bone side?
False. Wider in bone side
Increased functional load causes widening ot narrowing of the periodontal space?
Widening
Contents of the interstitial space?
- Blood vessels
- Nerves
- Lymphatics
- Interstitial tissue
Bundles of microfibrils?
Oxytalan
Acid resistant CT fibers?
Oxytalan
Fibers confined to the walls of blood vessels?
Elastic fibers
Fibers supporting blood vessels, lymphatics, and nerves?
Reticular fibers
Amorphous material that binds the tissues and fluids?
Ground substance
70% water
Vascular supply of the PDL. (3)
- dental artery
- interalveolar and interradicular arteries
- periosteal arteries
Interalveolar and interradicular arteries passes through what canal?
Volkman’s canal
The nerves of the PDL passes through what canal?
Canal of Zuckerkandl and Hirschfeld
Types of neural termination? (4)
- free nerve endings
- ruffini corpuscles
- coiled endings
- encapsulated spindle type ending
Most frequent type of nerve endings?
Free nerve endings
Nerve endings that appear dendritic and ends in terminal expansion?
Ruffini corpuscles
Mechanoreceptor nerve endings which perceives pressure?
Ruffini corpuscle
Nerve ending found at the root apex?
Ruffini corpuscle
Nerve ending found in the midregion of the PDL?
Coiled endings
Nerve ending with the lowest frequency?
Encapsulated spindle type
Nerve ending whose function is not determined?
Coiled ending
Continuous with intermediate fibers apical to the epithelial diaphragm?
Cushion Hammock ligament
Zone of loose, not well oriented collagen fibers?
Intermediate plexus
True or false. Intermediate plexus cannot be found in a completely formed PDL?
True
