18. Infratemporal Fossa

Question 1

Mumps: what is it? What structure does it affect differentially? Why?

Answer 1

Highly contagious virus of lymph glands
Parotid Gland
Affects this more because it is the Largest and Latest Developing of the Salivary Glands = more lymphatic tissue

Question 2

What are the 3 main fossa? Where are they located? What are their contents?

Answer 2

1. Temporal F: arcs from lateral skull, contains Temporalis m.
2. Infratemporal F: deep to mandibular ramus, inf to temporal fossa, lateral to pterygoid plate
   Contents: Mandibular Nerve (v3), Maxillary Artery, Medial/Lateral Pterygoid m., TMJ
3. Pterygopalatine F: deepest, b/w pterygoid plates of sphenoid and posterior maxilla, contains Maxillary Nerve (V2), sphenopalatine artery

Question 3

What are the branches of the main artery in the infratemporal fossa?

Answer 3

Maxillary Artery
Ext. Carotid = Superficial Temporal Artery + Maxillary Artery = 3 parts
1. Middle Menangial Artery, accessory, inf. alveolar
2. Deep Temporal, Buccal, Masseteric
3. Sphenopalatine into PPF/Nasal Cavity

Question 4

What are the branches of the main nerve in the infratemporal fossa?

Answer 4

V3 - mandibular nerve (exits foramen ovale)

1. Auriculotemporal n. - splits around middle mesangial a.
2. Inf. Alveolar n. - motor to muscles of mastication (mylohyoid, ant. belly of digastric), enters mandibular canal and exits as Mental n.
3. Lingual n. - to tongue, joined by chorda tympani, delivering taste/parasymps to ant. 2/3 tongue
4. Buccal n.

Question 5

What are the ligaments of the TMJ?

Answer 5

Temporomandibular L. - thickening of lateral joint capsule
Intraarticular disc - fibrocartilage b/w mandibular condyle and mandibular fossa of temporal
Sphenomandibular L. - from 1st arch cartilage (support mandible)
Stylomandibular L. - from 2nd arch cartilage (support mandible)

Question 6

What are the 4 muscles of mastication, their attachments, and their movements about the jaw?

Answer 6

1. Temporalis
   From temporal and parietal bones to coronoid process of mandible
   Fx: elevation/retraction of jaw
2. Masseter
   From Zygomatic arch to outside ramus/angle of mandible
   Fx: Elevation, protrusion, same-side lateral excursion
3. Medial Pterygoid
   From b/w Pterygoid plate to inside ramus/angle of mandible
   Fx: elevation, protrusion, contralateral lateral excursion
4. Lateral Pterygoid
   From lateral pterygoid plate to mandibular condyle (inf head) and intraarticular disc (sup head)
   Fx: protrusion, contralateral excursion, depression (pulls condyle out of mandibular fossa near articular tubercle