Periodontium Flashcards
What structures are part of the periodontium?
cementum, alveolar bone, gingiva, periodontal ligament
What does the periodontal ligament contain?
it is an organised connective tissue therefore - cells (fibroblasts), extracellular matrix, fibres, nerves, blood vessels
Which are the main cells found in the periodontal ligament?
Fibroblasts
What components make up the periodontal ligament matrix?
Hyaluronate glycosaminoglycans, proteoglycans, glycoproteins
What property does the periodontal ligament matrix have that enables it to stretch and return to its original shape?
behaves as a viscous elastic gel
What cells are found in the periodontal ligament?
Fibroblasts, cementoblasts, osteoclasts, cementoclasts, epithelial cells (called cell rests/debris of Malassez), defence cells
What is the name given to the epithelial cells in the PDL?
Cell rests or debris of Malassez
Function of the cell rests/debris of Malassez
Form cysts
Which cells participate in bone remodelling?
Osteoclasts
Function of bone remodelling
Regulates Ca2+ concentration and important for orthodontics
Which sensory receptors are found in the PDL?
mechanoreceptors and nociceptors
Function of mechanoreceptors
detects fibre, thickness and consistency of food. e.g. allows a different chewing mechanism for different foods
Function of nociceptors
Detect pain. Responsible for the jaw-jerk reflex
Which part of the nervous system controls vasoconstriction/blood vessels?
Autonomic (sympathetic)
Which 2 ligaments make up the periodontal fibres?
True periodontal ligament and gingival ligament
What is the true periodontal ligament?
Fibres that connect the tooth to the alveolar bone at or apical to the alveolar crest
What is the gingival ligament?
Fibres mainly above the alveolar crest, including free gingival fibres. Don’t connect to both the tooth and the alveolar bone, just connect to either one.
Function of the periodontal ligament
Attaches the tooth to the jaw, transmits biting forces to the alveolar bone where it dissipates, and has a sensory role (jaw-jerk reflex and chewing).
What is the approximate width of the PDL?
0.2mm
How is the width of the PDL measured?
Periodontal space is measured via a radiograph.
What is the name of the ligament that connects the tooth to the alveolar bone?
Alveolo-dental ligament
Which periodontal ligament connect the cementum of adjacent teeth?
Interdental ligament
Which fibre groups make up the alveolo-dental ligament?
Alveolar crest, horizontal, oblique, apical, inter-radicular (multi-rooted teeth)
Which fibres make up the interdental ligament?
trans-septal fibres
Examples of treatments that remove the PDL?
Implants, dentures
Why are patients who have had the PDL removed at risk of fracturing the prosthetic?
The mechanoreceptors and nociceptors have been removed and the sensation is transferred to less reliable sources (TMJ and mucosa). Difficulty establishing food texture.
