Temporomandibular Joint (TMJ)

Question 1

TMJ – MusclesMuscles of Mastication:
Medial Pterygoid:

O: medial surface of the lateral pterygoid plate(sphenoid), pyramidal process of the palatine bone, and maxillary tuberosity

I: inferior & posterior part of medial surface of ramus and angle of mandible foramen

A: closes the jaw, elevates and protracts the mandible

N: Trigeminal nerve (CN V)

Question 2

TMJ – MusclesMuscles of Mastication:
Temporalis:

O: floor of temporal fossa & fascia (deep temporal)

I: coronoid process & ramus of the mandible

A: closes the jaw, elevation of mandible, posterior fibres retract mandible

N: Trigeminal Nerve (CN V)

Question 3

TMJ – MusclesMuscles of Mastication:
Lateral Pterygoid:

O: superior head: lateral surface of greater wing of the sphenoid
O: inferior head: lateral surface of the lateral pterygoid(sphenoid)

I: anterior part of the condyle of the mandible and anterior margin of the articular disc of the TMJ

A: opens the jaw (depression), protrudes the mandible & moves the mandible side to side

N: Trigeminal Nerve (CN V)

Question 4

TMJ – MusclesMuscles of Mastication:
Masseter:

O: superficial part: zygomatic process of maxilla & lower border of the zygomatic arch
O: profundus (deep) part: posterior 1/3 of inferior border & medial surface of the zygomatic arch

I: superficial part: angle & ramus of mandible
I: deep part: superior ½ of ramus lateral surface of coronoid process of mandible

A: closes the jaw, elevation and retraction/protraction of the mandible, clenches teeth

N: trigeminal nerve (CN V)