Periodontal ligament Flashcards
What is it?
a specialised fibrous tissue which attaches teeth to the alveolar bone + the surrounding gingivae. it acts as a shock absorber to the teeth during chewing + its main fibres run between the alveolar bone + cementum covering the root of tooth. other fibres run between necks of the teeth + from cementum into surrounding gingivae
Alveolar crest fibres
run from alveolar bone to the cementum at the neck of the tooth; prevent tooth movements in (intrusion) + out (extrusion) of the socket, as well as resisting tilting + rotation
Horizontal fibres
run horizontally from the alveolar bone to the cementum, just below the crest fibres; resist tilting + rotation of the tooth
Oblique fibres
run at an angle from the alveolar bone down to the cementum; prevent intrusion + rotation of the tooth
Apical fibres
occur at the root apex + run between the bone + cementum; prevent extrusion + rotation of the tooth
Transeptal fibres
run between the cementum of adjacent teeth through the interdental region; maintain the gingival attachments between the teeth + therefore their positions in the dental arch
Free gingival fibres
run from the cervical cementum into the gingival papillae; maintain the gingival cuff around each tooth
1
its fibres are made up of a protein called collagen
2
they run in various directions, the end result being that the teeth are held in their sockets but can ‘bounce’ under normal chewing forces
3
this prevents tooth fracture + pain during normal occlusal loading + chewing actions
4
when excessive occlusal forces are applied, the resultant pain experienced by the pt tends to stop further overuse from occurring
5
the ligament has a sensory nerve supply which transmits pressure, pain, touch + temperature changes; the ability of the tooth to detect + transmit these sensations is called proprioception
6
inflammation of the ligament is called periodontitis + occurs during periodontal disease