They are the mandibular muscles or muscles of mastication. Muscles of the temporo-mandibular region 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.
