Periodontium

Question 1

Alveolar bone

Answer 1

• specialised ridge of bone where teeth sit in their sockets
• sole purpose is to support teeth
• outer layer made of lamina dura (shown on X-ray as continuous white line)
• inner layer is cancellous bone (spongey + allows nerves + blood vessels to supply teeth, jaws + surrounding tissue)
• teeth lie within individual sockets
• destruction of alveolar bone occurs in periodontal disease

Question 2

Gingiva

Answer 2

-correct term anatomical for gums
-specialised soft tissue covering alveolar process that are also in attachment with teeth at their necks
-continuous layer of epithelium only found in oral cavity
is firmly attached to alveolar bone as mucoperiosteal layer
three distinct areas on gingival coverage:
1. attached gingiva
2. marginal gingiva
3. functional tissues

Question 3

Gingival properties

Answer 3

• fits around neck of tooth like tight cuff
• crevice exist has a shallow space less than 3mm between tooth surface + gingival margin + contains epithelium
• healthy as pink + stippled surface
• inflammation is called gingivitis
• swollen appearance presents false pockets when probed
• can also be stimulated to overgrow + become hyper plastic

Question 4

Periodontal ligament

Answer 4

• specialised fibrous tissue which attaches teeth to alveolar bone + surrounding gingivae
• acts as shock absorber to teeth during chewing
• fibres run between alveolar bone + cementum, between necks of teeth + surrounding gingiva
• function is to prevent tooth movement such as tilting, rotating, intrasion + extrusion of the socket

Question 5

Periodontal ligament properties

Answer 5

• fibres made up of protein called collagen
• they run in various directions the result being teeth held in socket
• ligament has sensory nerve supply which transmits pain, pressure, touch + temperature changes
• inflammation of ligament is called periodontitis + occurs during periodontal disease

Question 6

Cementum

Answer 6

• calcified protective covering of root that anchors periodontal ligament to tooth, similar structure to bone
• formed by cementoblast cells + can continue laying down more tissue layers when required
• thickness may vary +changes throughout life depending on forces exerted on individual teeth
• contains no nerves or blood vessels, so received its nutrients from periodontal ligament