The Role Of Meckel’s Cartilage In Mandible Development

The Role Of Meckel’s Cartilage In Mandible Development

Question 1. Meckel’s Cartilage.
Answer:

• It is formed around 41st-45th day of intrauterine life.
• First structure to be formed is trigeminal nerve.
• Mesenchymal condensation occurs through.
  1. Activation of neurotrophic factors.
  2. Induction osteogenesis.
• Ossification occurs starting from bifurcation of inferior alveolar nerve.
• This ossification spreads below and around the nerve.
• Intramembranous ossification spreads dorsally and ventrally resulting in formation of body and ramus of mandible.
• This ossification stops at the site which forms lingula.
• Remaining Meckel’s cartilage forms.
  • Mental ossicles
  • Incus of sphenoid.
  • Anterior ligament of malleus
  • Sphenomandibular ligament.

Question 2. Write the persistent structures of Meckel’s cartilage.
Answer:

• Malleus and incus.
• Mental ossicles.
• Anterior ligament of malleus.
• Sphenomandibular ligament.
• Spine of sphenoid.

Question 3. Enumerate the muscles derived from second branchial arch.
Answer:

• Muscles of facial expression.
• Stylohyoid.
• Posterior belly of digastric.
• Stapedius.

Question 4. Derivatives of Third Branchial Arch
Answer:

Third Branchial Arch Skeletal component:

• Greater cornua of hyoid bone
• Lower part of the body of hyoid bone

Third Branchial Arch Muscles:

• Stylopharyngeus

Third Branchial Arch Nerve:

• Glosso-pharyngeal