Muscles of Mastication Flashcards
(24 cards)
What are the muscles of mastication?
Temporalis, masseter, lateral pterygoid and medial pterygoid
Where does temporalis arise from?
Bone of temporal fossa and temporal fascia
Where does masseter arise from?
Zygomatic arch and maxillary process of the zygomatic bone
Where does lateral pterygoid arise from?
Upper Head - Roof of infratemporal fossa
Lower Head- Lateral surface of the lateral plate of the pterygoid process.
Where does medial pterygoid arise from?
Deep Head - Medial surface of the lateral plate of the pterygoid surface and pyramidal process of the palatine bone
Superficial Head - Maxilla tuberosity and pyramidal process of palatine bone
Where does temporalis insert?
Coronoid process of mandible and anterior margin of ramus of mandible (near last molar tooth)
Where does masseter insert?
Lateral surface of ramus of mandible
Where does medial pterygoid insert?
Medial surface of mandible near angle
Where does lateral pterygoid insert?
Capsule of TMJ in the region to the articular disc and to the pterygoid fovea on the neck of the mandible
What innervates temporalis?
Deep temporal nerves from the anterior trunk of the mandibular nerve [V3]
What innervates masseter?
Masseteric nerve from the anterior trunk of the mandibular nerve [V3]
What innervates medial pterygoid?
Mandibular Nerve [V3]
What innervates lateral pterygoid?
Anterior trunk of the mandibular nerve [V3] or from the buccal branch
Which muscle of mastication is the strongest?
Masseter
What is the function of temporalis?
Resting tonus, elevation, retraction and ipsilateral excursion
What Is the function of masseter?
Elevation, retraction and ipsilateral excursion
What is the function of lateral pterygoid?
Protrusion, depression and Contralateral excursion
What is the function of medial pterygoid ?
Elevation, protrusion and contralateral excursion
What does resting tonus mean?
Normal rest position
What does elevation mean?
Raise the jaw
What does retrusion mean?
Bring the jaw back
What does ipsilateral excursion mean?
Moving the mandible to the same side as the muscle
What does contralateral excursion mean?
Moving the mandible to the opposite side of the muscle
What does protrusion mean?
Bring the jaw forward
