Muscles Of Mastication Flashcards
What are the 4 muscles of mastication
- masseter
- temporalis
- medial pterygoid
- lateral pterygoid
What is the most powerful muscle of mastication
Masseter
Where do the muscles of mastication develop from
The first pharyngeal arch
What nerve innervates the muscles of mastication
Innervated by the Mandibular branch of the trigeminal nerve
Where does the massester lie
Superficially to the pterygoids and the temporalis
Explain the attachments of the masseter
- superficial part originates from the maxillary process of the zygomatic bone
- deep part originates from the zygomatic arch of the temporal bone
- both parts attach to the ramus of the mandible
What are the actions of the masseter
Elevates the mandible closing the mouth
How do you test the masseter clinically
Have the patient clench their jaw
Where does the temporalis originate from
The temporal fossa - a shallow depression on the lateral aspect of the skull
Covered by tough fascia
What are the attachments of the temporalis
- originates from the temporal fossa, condenses into a tendon which inserts onto the cornoid process of the mandible
Where does the temporalis insert into the mandible
The coronoid process of the mandible
Where does the masseter insert onto the mandible
The ramus of the mandible
What are the actions of the temporalis
Elevates the mandible, closing the mouth, also retracts the mandible pulling the jaw posteriorly
Where is the medial pterygoid located
Inferiority to the lateral pterygoid
What are the two heads of medial pterygoid muscle
Deep and superficial
What are the attachments of the superficial part of the medial pterygoid
Superficial head originates from the maxillary tuberosity and the pyramidal process of the palatine bone
What are the attachments of the deep head of the medial pterygoid
The deep head originates from the medial aspect of the lateral pterygoid plate of the sphenoid bone
Where does the medial pterygoid attach to the mandible
Both heads attach to the mandible near the angle of the mandible
What is the role of the medial pterygoid
Elevates the mandible closing the mouth
What are the two heads of the lateral pterygoid
Superior and inferior
What are the attachments of the superior head of the lateral pterygoid
Originates from the greater wing of the sphenoid
What are the attachments of the inferior head of the lateral pterygoid
Originates from the lateral pterygoid plate of the sphenoid
Where does the lateral pterygoid attach to the mandible
The two heads converge into a tendon which attaches at the neck of the mandible
Describe the actions of the lateral pterygoid
Acting bilaterally the lateral pterygoids protract the mandible, pushing the jaw forwards
Note contraction of one side will produce movement on contra lateral side
