Muscles of the temporo-mandibular region
MUSCLES OF TEMPORO-MANDIBULAR REGION
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They are the mandibular muscles or muscles of mastication. They are as follows
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Masseter
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Temporalis
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Pterygoideus medialis
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Pterygoideus lateralis
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Digastricus
Masseter
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This muscle is situated on the lateral face of the broad part of the ramus of the mandible.
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Origin: Zygomatic arch, facial crest and facial tuberosity.
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Insertion: Lateral face and posterior border of the vertical ramus of the mandible.
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Action: To close the jaws and move the mandible forward and upward; acting singly to produce lateral motion .
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Blood supply: Transverse facial, masseteric, branch from external maxillary and deep temporal arteries.
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Temporalis
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It is situated in the temporal fossa.
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Origin: Rough part of the temporal fossa.
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Insertion: Coronoid process of the mandible.
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Action: To raise the lower jaw.
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Blood supply: Deep temporal artery.
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Pterygoideus medialis
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This muscle is situated on the medial face of the vertical ramus of the mandible opposite to the masseter.
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Origin: Lateral face of perpendicular part of the palatine and pterygoid crest of the Sphenoid.
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Insertion: Medial surface of the vertical ramus of the mandible, behind the mandibular foramen.
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Action: To raise the lower jaw and acting singly to assist in the lateral movement of the jaw.
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Blood supply: One or two pterygoid arteries from the internal maxillary.
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Pterygoideus lateralis
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It is a small muscle situated lateral to the upper part of the preceding muscle
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Origin: Pterygoid process of the sphenoid bone.
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Insertion: Medial face of the neck and condyle of the mandible and the articular disc.
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Action: To draw the jaw forwards and acting singly to move it to the opposite side.
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Blood supply: a branch from mandibular artery
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Digastricus
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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.
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Origin: Paramastoid process.
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Insertion: Medial face of the horizontal ramus near the ventral border.
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(Note: The two anterior bellies are connected by a band situated below the mylohyoideus is called as transversus mandibulae)
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Action: To depress the lower jaw.
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Nerve supply: Facial and mandibular nerves.
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Last modified: Saturday, 15 October 2011, 9:00 AM