3-MOM

- Attach to mandible and effect its movement

- Mastication

- Speech

- Resting posture of the mandible

What are the functions of the muscles of mastication?

- Depression

- Elevation

- Protrusion

- Retrusion

- Lateral deviation

Motions of the mandible:

Depression

What is the following movement:

Open the mouth

Elevation

What is the following movement:

Close the mouth

Protrusion

What is the following movement:

Move mandible anteriorly

Retrusion

What is the following movement:

Move mandible posteriorly

Lateral deviation

What is the following movement:

Move the mandible to the side

temporalis m.

masseter m.

which two muscles of mastication can be palpated externally?

lateral pterygoid m.

medial pterygoid m.

which two muscles of mastication can be palpated internally?

temporalis m.

masseter m.

lateral pterygoid m.

medial pterygoid m.

What are the four primary muscle of mastication?

CN V3 (mandibular division of the trigeminal nerve)

innervation for the muscles of mastication:

medial pterygoid n.

which nerve for muscles of mastication does not come of the anterior division of V3, but the trunk?

The inferior head of lateral pterygoid is larger than the superior head

The lateral pterygoid has 2 heads, which one is larger?

internal pterygoid

The medial pterygoid is also referred to as the...

external pterygoid

The lateral pterygoid is also referred to as the...

Temporalis m.

Identify the structure at #1

External pterygoid m.

Identify the structure at #2

Tongue

Identify the structure at #3

Buccinator m.

Identify the structure at #4

Mylohyoid m.

Identify the structure at #5

Digastric m. (anterior belly)

Identify the structure at #6

Geniohyoid m. (deep to other mm.)

Identify the structure at #7

Orbicularis oris m.

Identify the structure at #8

Masseter m.

Identify the structure at #9

Internal pterygoid m.

Identify the structure at #10

pterygoid part of maxillary artery (2nd part)

blood supply for the muscles of mastication come from the:

• anterior belly of digastric m.

• myohyoid m.

• geniohyoid m.

• buccinator

• Tensor vili palatini

Accessory muscles of mastication?

CN VII

what nerve pierces through the parotid gland?

masseter m.

what muscles lies deep to the parotid gland?

buccinator m.

what muscle does the parotid duct pierce?

masseter m.

the transverse facial artery will supply the anterior surface of what muscle?

transverse facial a.

what artery runs superior to the parotid duct?

Masseter m.

The facial artery is anterior to what muscle at the inferior border of the mandible?

Frontal, middle, & parietal branches of superficial temporal a.

Identify the structure at #1

Superficial temporal a.

Identify the structure at #2

Transverse facial a.

Identify the structure at #3

Facial a.

Identify the structure at #4

Parotid gland and duct

Identify the structure at #5

facial a.

what artery runs through the antegonial notch to supply structures in the face?

superficial temporal a.

the transverse facial artery is a branch of the:

external carotid a.

the facial artery is a branch of the:

facial a.

what artery runs inferior to the masseter muscle?

Masseter is lateral to ramus of mandible

Where is the masseter located in relation to the ramus?

anterior to zygomaticotemporal suture

the superficial fibers of the masseter m. arise:

along entire zygomatic arch

the deep fibers of the masseter m. arise:

zygomatic process of maxilla

3rd fibers of the masseter m. would arise from:

lateral ramus of mandible

the masseter m. inserts onto the:

Superficial fibers insert near the inferior border mandible

Deep fibers insert more superiorly

Where do superficial fibers of the masseter m. insert? Where do deep fibers insert?

masseter m.

medial pterygoid m.

what two muscles form a mandibular sling for the mandible?

Superficial masseter

Identify the structure at #1

Deep masseter

Identify the structure at #2

masseteric a.

transverse facial aa.

facial a.

arterial supply to the masseter m. is done by:

mandibular notch

the masseteric nerve and artery pass through what structure to reach its destination?

•Elevates mandible

•Deep fibers retract mandible

•Slight ability to laterally deviate mandible

muscle actions of masseter muscle:

Lateral pterygoid m.

What is the main muscle for lateral deviation of the mandible?

- Coronoid process

- Ascending ramus below the plane of occlusion into the retromolar pad (can be traumatized with inferior alveolar nerve block)

what is the point of insertion for the temporalis m.?

Temporal fossa and deep surface of temporal fascia

what is the origin of the temporalis m.?

1. Temporalis superficial investing fascia

2. Superficial investing fascia extending from the masseteric fascia (deep)

Potential space between the 2 layers

What are the two layers of fascia superficial to the temporalis muscle? What do they create?

Important when considering the spread of infection along fascial planes

- Tendon of temporalis muscle and its 2 layers of fascia extends into the oral cavity

What is important to know about the potential space between the 2 layers of fascia of the temporalis muscle?

- Anterior fibers elevate

- Middle fibers elevate and retract

- Posterior fibers retract

muscle actions of temporalis muscle:

Posterior fibers of temporalis m. along with gravity

What is responsible for maintaining the resting posture of the mandible?

trismus

restricted motion of jaw or opening of the mouth:

temporalis m.

trismus affects what muscle of masticaiton?

anterior and posterior deep temporal nn.

innervation for temporalis m.:

deep to muscle: anterior and posterior deep temporal aa.

superficial to muscle: superficial temporal a. & middle temporal a.

blood supply for temporalis m.:

Coronoid process

Ascending ramus

Retromolar pad

Temporalis insertion points:

Superior temporal line

Identify the structure

Inferior temporal line

Identify the structure

Mandibular notch (clinically referred to as sigmoid notch)

Identify the structure

Coronoid process

Identify the structure

Condylar process

Identify the structure

Temporal fossa

Identify the structure

Infratemporal fossa

Identify the structure

Angle (gonial angle)

Identify the structure

Zygomatico-temporal suture

Identify the structure at the blue box

pterygoid part of maxillary artery

the anterior and posterior deep temporal aa. are branches of the:

Zygomatic process of maxilla

Identify the structure at #1

Zygomatic bone

Identify the structure at #2

Zygomatic process of temporal bone

Identify the structure at #3

Pterygomaxillary fissure

Identify the structure at #1

Infratemporal surface of maxilla with Posterior Superior Alveolar Foramina

Identify the structure at #2

Pyramidal Process of Palatine bone

Identify the structure at #3

Greater wing of sphenoid

Identify the structure at GWS

Infratemporal crest sphenoid

Identify the structure at ITC

Sphenopalatine foramen

Identify the structure at SPF

Lateral pterygoid plate

Identify the structure at LPP

Temporal fossa

Temporalis muscle occupies what fossa?

maxilla

zygomatic

temporal

what bones contribute to the zygomatic arch:

True - the superior and inferior heads of the lateral pterygoid

T/F: The lateral pterygoid has 2 heads immediately adjacent to one another

lateral pterygoid n. (V3)

innervation for lateral pterygoid m.

Lateral pterygoid a from the 2nd part of the maxillary artery (muscular or pterygoid portion)

Blood supply of lateral ptyergoid m:

pterygoid part of maxillary artery

the lateral pterygoid a. is a branch of the:

posterior superior alveolar foramina

identify the structure (at the arrows):

Smaller Superior head arises roof Infratemporal Fossa, inferior surface of Greater Wing Sphenoid & Infratemporal Crest

origin for superior head of lateral pterygoid m.:

pterygoid fovea of mandible only OR

Pterygoid fovea and the TMJ disc

insertion for superior head of lateral pterygoid m.:

lateral surface of lateral pterygoid plate

origin for inferior head of lateral pterygoid m.:

pterygoid fovea of mandible

insertion for inferior head of lateral pterygoid m.:

- contracts when large elevators of the mandible are contracting

- helps coordinate closing movement of the mandible

muscle action for superior head of lateral pterygoid m.

results in protrusion and depression of the mandible

muscle action: bilateral contraction of inferior head of lateral pterygoid m.

draws the condyle on the side which is contracting medially which results in a lateral deviation of the mandible to the opposite side

muscle action: unilateral contraction of inferior head of lateral pterygoid m.