Dissection 7-Infratemporal And Temporal Fossae

Question 1

Boundaries of the Temporal Fossa

Answer 1

Deep: parts of the frontal, parietal, temporal and sphenoid bones

Superficial: temporal fascia

Superior and Posterior: superior temporal line

Anterior: frontal and zygomatic bones

Inferior: zygomatic arch, infratemporal crest of the sphenoid bone, mandibular fossa and article tubercle

Question 2

Mandibular Foramen

Answer 2

-for the inferior alveolar nerve, artery and vein

Question 3

Mylohyoid Groove

Answer 3

-for the mylohyoid nerve and vessels

Question 4

Masseter Muscle

Answer 4

Superior attachment: inferior border of the zyogmatic arch

Inferior attachment: lateral surface of the ramus of the mandible

• elevates the mandible (closes the jaw) and protrudes the mandible
• innervated by the masseteric branch of the mandibular division of the trigeminal nerve

Question 5

Temporalis Muscle

Answer 5

Primary content of the temporal fossa

• attaches to the deep surface of the temporal fascia
• inferior attachment: coronoid process of the mandible
• fibers of the anterior portion have a vertical direction (elevation of the mandible)
• fibers of the posterior portion have a more horizontal direction (recursion of the mandible)

-innervation: deep temporal nerves (branches of the mandibular division of the trigeminal nerve)

Question 6

Temporal vessels and Auriculotemporal Nerve

Answer 6

-located in the scalp, superficial to the temporal fascia

Question 7

Lateral Pterygoid Muscle

Answer 7

• has 2 heads
• anterior attachment of the superior head: infratemporal surface of the greater wing of the sphenoid bone
• anterior attachment of the inferior head: lateral surface of the lateral plate of the pterygoid process
• posterior attachments of the lateral pterygoid muscle are the articular disc within the capsule of the temperomandibular joint and the neck of the mandible

-depresses and protrudes the mandible (opens the jaw)

Question 8

Inferior Alveolar nerve, artery, and vein

Answer 8

• inferior to the lateral pterygoid muscle
• travels in the mandibular foramen

-provides sensory innervation to the mandibular teeth

Question 9

Mylohyoid Nerve

Answer 9

Arises from the inferior alveolar nerve just before it enters the mandibular foramen and runs in the mylohyoid groove

Question 10

Mental Nerve

Answer 10

-a branch of the inferior alveolar nerve, which passes through the mental foramen to innervate the chin and lower lip

Question 11

Lingual Nerve

Answer 11

• located just anterior to the inferior alveolar nerve
• passes medial to the third mandibular molar tooth and it innervates the mucosa of the anterior 2/3s of the tongue and floor of the oral cavity

Question 12

Medial Pterygoid Muscle

Answer 12

• inferior to the lateral pterygoid muscle
• the lingual nerve and the inferior alveolar nerve pass between the inferior border of the lateral Pterygoid Muscle and the medial pterygoid muscle and can be used as a guide to separate the 2 muscles
• proximal attachments: maxilla and medial surface of the lateral plate of the pterygoid process
• distal attachment: inner surface of the ramus of the mandible
• elevates the mandible (closes the jaw) and protrudes it

Question 13

External Carotid Artery

Answer 13

• bifurcated into the maxillary artery and superficial temporal artery
• the maxillary artery crosses either the superficial 2/3s or the deep surface 1/3 of the lateral pterygoid muscle

Question 14

Middle Meningeal Artery

Answer 14

-arises medial to the neck of the mandible and courses superiorly, passing thru a split in the auriculotemporal nerve. Passes through the foramen spinosum, enters the middle cranial fossa, and supplies the dura mater. This relationship with the auriculotemporal nerve and the foramen spinosum will only be seen after the lateral pterygoid is removed

Question 15

Deep Temporal Arteries (anterior and Posterior)

Answer 15

-pass superiorly and laterally across the roof of the infratemporal fossa at bone level and enter the deep surface of the temporalis muscle

Question 16

Masseteric Artery

Answer 16

-courses laterally and passes through the madibular notch to enter the deep surface of the masseter muscle

Question 17

Inferior Alveolar Artery

Answer 17

-enters the mandibular foramen with the inferior alveolar nerve

Question 18

Buccal Artery

Answer 18

-passes anteriorly to supply the cheek

Question 19

Pterygomaxillary Fissure

Answer 19

-maxillary artery disappears into this

before it does, the maxillary artery divides into 4 branches:

• Posterior superior alveolar artery: enters the infratemporal surface of the maxilla
• infraorbital artery
• descending palatine artery
• sphenopalatine artery

Question 20

Chorda Tympani Nerve

Answer 20

-joins the posterior side of the lingual nerve

Question 21

Auriculotemporal nerve

Answer 21

Doesn’t always split around the middle meningeal artery but always passes nearby

-courses laterally to the anterior side of the external acoustic meatus, just posterior to the ramus of the mandible

Question 22

Dental Anesthesia

Answer 22

A mandibular nerve block is produced by injecting an anesthetic agent into the infratemporal fossa. Understand from your dissection that the mandibular nerve block will anesthetize not only the mandibular teeth, but also the lower lip, the chin, and the tongue