Birbeck’s Granules And PDL Fibers Explained For Dental Students

Birbeck’s Granules And PDL Fibers Explained For Dental Students

Question 1. Birbeck’s granules
Answer:

• They are named after its discoverer Michael Stanley Clive Birbeck
• It is a rod-shaped cytoplasmic organelle
• Found in Langerhans cells

Birbeck’s granules Functions:

• They migrate to the periphery of Langerhans cells and release its contents into the extracellular matrix
• Act as receptor-mediated endocytosis

Question 2. Principal fibers
Answer:

1. Trans-septal fibers
   • Connects cementum of one tooth with that of other
2. Alveolar crest
   • Extends from cementum to alveolar crest

Principal fibers Functions:

1. • Retains tooth in the socket
   • Retains lateral tooth movement
2. Horizontal Group
   • Extends from cementum to alveolar bone
3. Oblique group
   • Extends coronally from the cementum to the bone
   • Periodontal Ligament

Functions:

• Resist axially directed forces
• Apical group
• Extends from the cementum to the bone of the alveolar fundus

Functions:

• Prevents tipping movement
• Resists luxation
• Inter-radicular fibers
• It is present between the cementum of multi-rooted teeth

Functions:

• Resists luxation Resists tipping and torquing

Question 3. The protective function of PDL
Answer:

• The periodontal ligament protects vessels and nerves from mechanical forces
• It offers resistance to impact from occlusal forces
• Acts as a shock absorber to transmit occlusal forces to the bone.