Periodontal Ligament Fibers and Periodontium Structures

Overview of Periodontium

• The periodontium is composed of four main tissues that surround the tooth:
  1. Gingiva (Gums)
  2. Periodontal Ligament Fibers
  3. Cementum
  4. Bone

Periodontal Ligament Fibers

• These fibers are the black lines surrounding the tooth.
• They connect the tooth to the cementum on one side and the bone on the other.
• Endings of these fibers are known as Sharpey's Fibers.

Cementum

• Covers the entire root of the tooth.
• It's softer than dentin and enamel and is attached to the dentin.
• Cementum covers dentinal tubules, preventing sensitivity by blocking exposure.
• Important to be cautious during cleaning to avoid removing cementum and exposing dentinal tubules.
• Cementum thickens with age, especially with grinding and clenching.

Bone

• Surrounds the tooth and forms part of the periodontium.
• Alveolar Bone Proper:
  • Also known as the cribiform plate.
  • Lines the socket and the inside part of the tooth socket (alveolus).
• Cortical Bone:
  • Also called compact bone.
  • Forms the outer wall of the bone.
• Cancellous Bone:
  • Also known as spongy bone, located inside the cortical bone.
  • Found in interproximal areas (between teeth).

Periosteum

• A layer surrounding the bone.
• Located beneath the connective tissue and above the bone.

Tissue Layers in the Mouth

1. Epithelial Tissue (gums)
2. Connective Tissue (underneath epithelial, contains blood supply)
3. Periosteum (layer around the bone)
4. Bone

Summary

• Understanding the structure and function of these tissues is essential for the study of periodontium.
• These terms and concepts will be referenced throughout the periodontium course.