Periodontium

Question 1

What is the periodontal ligament?

Answer 1

Connective tissue contains cells, extracellular matrix, fibres, nerves and blood vessels. Attaches tooth to jaw. Transmits biting forces to alveolar bone. Width around 0.2mm.

Question 2

What is the matrix of periodontal ligament?

Answer 2

Behaves like viscous elastic gel and contains hyaluronate glycosaminoglycans, proteoglycans and glycoproteins.

Question 3

What are the cells of periodontal ligament?

Answer 3

Fibroblasts, cementoblasts, cementoclasts, osteoclasts, defence cells and epithelial cells (cell rests of malassez - clusters of residual cells from hertwig’s epithelium).

Question 4

What are the nerves in periodontal ligament?

Answer 4

Sensory - mechanoreceptors and nociceptors

Autonomic - sympathetic for blood vessel control

Question 5

What are the different fibres of periodontal ligament?

Answer 5

Apical, oblique, horizontal, alveolar crest, transeptal, free gingival.

Question 6

What is true periodontal ligament?

Answer 6

Fibres connecting tooth to bone at or apical to alveolar crescent.

Question 7

What is gingival ligament?

Answer 7

Fibres mainly above the alveolar crescent including free gingival fibres. Can be tooth to gingiva or bone to gingiva.

Question 8

What is interdental septum?

Answer 8

Alveolar bone between two teeth.

Question 9

What is periodontal ligament loading?

Answer 9

Application of brief forces and measuring tooth movement.