Lecture 11: Deep Face and Infratemporal Fossa Flashcards
What are the attachments of the sphenomandibular ligament; what neurovasculature passes between this ligament and the neck of the mandible?
- Between the sphenoidal spine and lingula of the mandible
- Maxillary artery/vein and auriculotemporal nerve pass between
What are the 4 muscles of mastification and which muscle assists these muscles?
1) Temporalis m.
2) Masseter m.
3) Lateral pterygoid m.
4) Medial pterygoid m.
*The buccinator muscle assists these muscles
The muscles of mastification are all innervated by what nerve?
- Branches of the mandibular division (V3) of Trigeminal
- Each branch is named for the corresponding muscle
The muscles of mastification receive blood supply from what artery/branch?
- Branches of the second (pterygoid) part of Maxillary A.
- Each branch is named for the corresponding muscle
What is the insertion for the Temporalis muscle of mastification?
Coronoid process of mandible
What is the action of the vertical, horizontal, and unilateral fibers of the Temporalis muscle of mastification?
Vertical: Elevate the mandible
Horizontal: Retract (retrude) mandible
Unilateral: Lateral movement of mandible (chewing)
What is the origin and insertion of the Superficial versus Deep heads of the Masseter muscle?
Origin: Zygomatic bone (superficial) and Zygomatic arch (deep)
Insertion: Mandibular angle (superficial) and Mandibular ramus/inferior coronoid process (deep)
What is the action of the Masseter m.?
- Elevates mandible
- Assists in protraction and retraction
- Assists in side-to-side motion
What is the origin and insertion of the superior versus inferior head of the Lateral Pterygoid muscle?
Origin (superior): Greater wing of sphenoid bone
Insertion (superior): Mandible and tempromandibular joint (articular disk)
Origin (inferior): Lateral pterygoid plate
Insertion (inferior): Mandible
What are the actions of the lateral pterygoid muscle working bilaterally vs. unilaterally?
Bilaterally: protrudes mandible (pulls articular disk forward) and opens mouth
Unilaterally: alternating actions along with ipsilateral medial pterygoid, result in side-to-side movements necessary for grinding
What is the origin and insertion of the superficial versus deep head of the Medial Pterygoid muscle?
Origin (superficial): Maxila (maxillary tuberosity) and palatine bone
Origin (deep): Medial surface of lateral pterygoid late and pterygoid fossa
Insertion (superficial/deep): Pterygoid rugosity on medial surface of the mandibular angle
What is the action of the Medial Pterygoid muscle working bilaterally and unilaterally?
Bilaterally: elevation of mandible; also acts with lateral pterygod to assist in protrusion of mandible
Unilaterally: acts with ipsilateral pterygoid to protrude mandible and produce medial movement towards the opposite side. Alternating actions between right and left side results in side-to-side chewing movements
Which muscle is most important for opening the manible and what musle assist this movement?
- Lateral Pterygoid m.
Assisted by (suprahyoid muscles):
- Digastric m.
- Geniohyoid
- Mylohyoid
- Stylohyoid
What is the function of the infrahyoid muscles in opening the mandible?
- Sternohyoid, Sternothyroid, Thyrohyoid, and Omohyoid
- Help to fix the hyoid in place, allowing us to open mandible
Which 3 muscles are elevators of the mandible?
- Temporalis m.
- Medial Pterygoid m.
- Masseter m.
Which muscle groups work together for lateral movements of the mandible?
Ipsilateral Temporalis and Masseter + Contralateral Pterygoids
What is the function of the Sphenomandibular and Stylomandibular ligamens in regards to the TMJ?
- Limit inferior excursion of the TMJ
- Prevents dislocation when opening the mouth
What neurovasculature passes between the two heads of the lateral pterygoid m.?
- Maxillary artery
- Buccal nerve (buccal branch of V3; long buccal nerve, buccinator nerve)
What neurovasculature passes between the medial and lateral pterygoids?
- Inferior alveolar nerve
- Lingual nerve
Describe the positional shift in structures of the TMJ in TMJ dislocation; is anterior or posterior dislocation more common?
- Taking a large bite, excess contraction of lateraly pterygoids may cause heads of manible to dislocated anteriorly (pass anterior to the articular tubercles)
- Mandible remains depressd and person is unable to close his or her mouth
- Posterior dislocation is uncommon, due to presence of postglenoid tubercle and strong intinsic lateral ligament
Injury associated with traumatic dislocation and rupture of the articular capsule of the TMJ affects which nerve and leads to what?
- Articular branches of the Auriculotemporal nerve
- Leads to laxity and instability of the TMJ
What are the 3 divisions of the TMJ and what type of joint is each?
1) Superior joint is a gliding joint between mandibular fossa and articular tubercle, and the articular disk
2) Inferior joint is a hinge-type joint between the articular disk and the mandibular condyle
3) Articular disk is attached to the sphenomeniscus musle and the strong lateral (collateral) lig.
What neurovasculature is at risk from a fracture of the neck vs. ramus vs. body of the mandible?
Neck: Maxillary artery and vein, and/or Auriculotemporal nerve
Ramus: Lingual or Inferior Alveolar nerves
Body: Inferior Alveolar nerve and vessels
What are the boundaries of the Infratemporal Fossa (lateral, anterior, medial, roof, posterior, and inferior)?
Lateral = Ramus of Mandible
Anterior = Maxilla
Medial = Lateral Pterygoid Plate
Roof = Sphenoid (greater wing)
Posterior = Tympanic plate and Mastoid/Styloid Processes
Inferior = Angle of the Mandible
What muscle and vein is associated with yawning?
- Lateral Pterygoid m.
- Contraction of muscle pushes on pterygoid plexus, assisting in venous return.
Which nerves and ganglion are found in the Infratemporal fossa?
- Inferior alveolar (V3)
- Lingual (V3)
- Buccal (V3)
- Chorda tympani (CN VII)
- Otic ganglion
What nerve passes through the Foramen Ovale?
Mandibular nerve (V3)
What nerve passes through the Foramen Rotundum?
Maxillary nerve (V2)
How is anesthesia provided to nerve block the lower teeth; which nerve and where is the injection site?
- Inferior Alveolar nerve a branch of Mandibular (V3)
- Site of injection is between Coronoid NotchandPterygomandibular Raphe
