Periodontal Ligament Flashcards
The student shall be able to define PDL and describe its composition and functions in detail. The student shall be able to memorise blood supply, lymphatics and nerve supply of PDL. The student will also determine the age changes of PDL
Periodontium comprises of?
Cementum,
Periodontal ligament,
Bone lining the tooth socket
That part of the gingiva facing the tooth
The average width of periodontal ligament is?
0.21 to 0.38mm
Periodontal ligament is thinnest around which part of the root
Middle third. It is widest at the region near alveolar crest followed by the apical third. This gives it an hour-glass shape
The dental follicle cells are composed of which cells?
Mesenchymal cells of the dental follicle proper and the perifollicular mesenchyme
Which of the following types of cells are present in a healthy periodontal ligament?
Synthetic Resorptive cells Progenitor Defence cells Epithelial cell rests of Malassez
What is Periodontal Ligament Homeostasis
Uniqueness that the PDL width remains more or less constant inspite of it lying between 2 hard structures.
This is due to various molecules secreted by various cells in the PDL.
1. Msx2
2. Balance between bone sialoprotein and osteopontin
3. Matrix ‘Gla’ protein.
4. RGD-cementum attachment protein
5. Prostaglandins.
6. PDL can increase in width when functional demand is increased and vice versa.
What are the typical characteristics of a periodontal ligament fibroblasts?
They are derived from ectomesenchyme of dental papilla as well as dental follicle
They appear as ovoid or elongated cells with pseudopodia like process (cilia).
The ones close to the bone side have abundant alkaline phophatase.
The ones close to cementum are derived from dental papilla and the ones close to bone from perivascular mesenchyme
They are arranged with long axis parallel to the direction of collagen fibrils.
What is incorporated into collagen polypeptides known as procollagen molecules
Proline
What is the shape of osteoblasts?
Cuboidal
In Osteoclasts, the part of plasma membrane lying adjacent to the bone that is being resorbed is?
Ruffled
Degradation of collagen is considered to be intracellular event. True or False?
True
Which are the resorptive cells of PDL?
Osteoclasts, Fibroblasts and Cementoclasts
Progenitor cells are ____ in size and nucleus is ___ faced.
Small,
closed
What are epithelial rests of Malassez?
Remnants of Hertwig Epithelial Root Sheath
Epithelial rests of Malassez may calcify to become?
Cementicles
As part of an immune response to foreign pathogens, Mast cells release____
Histamine
Numerous cytoplasmic granules stain with which dyes
Basic dyes
Which cells phagocytose dead cells?
Macrophages
In Eosinophils, Granules have crystalloid structures and exhibit bright red staining properties with which dyes?
Acidic dyes like eosin
The amount of collagen in a tissue can be determined by its ___content
Hydroxyproline