Muscles of the temporo-mandibular region

MUSCLES OF TEMPORO-MANDIBULAR REGION

They are the mandibular muscles or muscles of mastication. They are as follows

  • Masseter
  • Temporalis
  • Pterygoideus medialis
  • Pterygoideus lateralis
  • Digastricus

Masseter

  • This muscle is situated on the lateral face of the broad part of the ramus of the mandible.
  • Origin:  Zygomatic arch, facial crest and facial tuberosity.
  • Insertion: Lateral face and posterior border of the vertical ramus of the mandible.
  • Action: To close the jaws and move the mandible forward and upward; acting singly to produce lateral motion .
  • Blood supply: Transverse facial, masseteric, branch from external maxillary and deep temporal arteries.
  • Nerve supply: Mandibular nerve.

Temporalis

  • It is situated in the temporal fossa.
  • Origin: Rough part of the temporal fossa.
  • Insertion: Coronoid process of the mandible.
  • Action: To raise the lower jaw.
  • Blood supply: Deep temporal artery.
  • Nerve supply: Mandibular nerve.

Pterygoideus medialis

  • This muscle is situated on the medial face of the vertical ramus of the mandible opposite to the masseter.
  • Origin: Lateral face of perpendicular part of the palatine and pterygoid crest of the Sphenoid.
  • Insertion: Medial surface of the vertical ramus of the mandible, behind the mandibular foramen.
  • Action: To raise the lower jaw and acting singly to assist in the lateral movement of the jaw.
  • Blood supply: One or two pterygoid arteries from the internal maxillary.
  • Nerve supply: Mandibular nerve.

Pterygoideus lateralis

  • It is a small muscle situated lateral to the upper part of the preceding muscle
  • Origin: Pterygoid process of the sphenoid bone.
  • Insertion: Medial face of the neck and condyle of the mandible and the articular disc.
  • Action: To draw the jaw forwards and acting singly to move it to the opposite side.
  • Blood supply:    a branch from mandibular artery 
  • Nerve supply: Mandibular nerve.

Digastricus

  • It is a long muscle extending from the paramastoid process to the medial face of the horizontal ramus. It presents two muscular bellies with an intermediate tendon.
  • Origin: Paramastoid process.
  • Insertion: Medial face of the horizontal ramus near the ventral border.
  • (Note: The two anterior bellies are connected by a band situated below the mylohyoideus is called as transversus mandibulae)
  • Action: To depress the lower jaw.
  • Blood supply:    a branch from external maxillary artery.
  • Nerve supply: Facial and mandibular nerves.

Last modified: Saturday, 15 October 2011, 9:00 AM