OCB02-1020 Structure and function of periodontal ligament Flashcards
What is the periodontal ligament?
Specialised dense fibrous tissue which attaches the tooth to the alveolar bone
How thick is the PDL?
Approximately 0.2mm thick
Where is the PDL at its thinnest?
At the apex
Hows does the PDL in the deciduous tooth differ to that of the permanent?
Deciduous tooth PDL is wider than permanent
What are the functions of PDL?
Retention of the tooth
Involved in the attachment between tooth and alveolar bone
Adsorption of occlusal forces
What are the cells of the PDL?
Fibroblasts
Blood Vessel
Nerve Fibres
Defence cells like mast cells, macrophages
What is the matrix made up of?
Types I, III, V collagen
Proteoglycans
Elastin
What are epithelial cell rests of Malassez?
These are remnant of the HERS
No known function
Can cause cysts in unerupted teeth which can lead to the fracturing of the teeth
What are principal fibres?
Arranged in longitudinally which attach the cementum to bundle bone
What are the principle fibres of the PDL?
Oblique
Apical
Horizontal
Crestal fibres
What are Sharpey’s fibres?
The portion of fibres of the PDL that are found in the cementum or alveolar bones
What are oxyalatan fibres? and what is their orientation?
Elastic fibres specific to PDL
Orientated perpendicular to tooth root
What is the blood supply to the PDL an anastomosis of?
Apical vessel
Through alveolar bone
Gingival vessel
What is the main blood supply to the PDL?
From the superior and inferior alveolar arteries
What is the PDL derived from?
Dental follicle mesenchymal cells
