Origin: Medial Surface of Lateral Pterygoid Plate & Posterior Maxilla
Insertion: Internal Ramus of the Mandible
Action: Elevation & Protraction
**Masseter & Medial Pterygoid act as a sling for the Mandible
D. Lateral Pterygoid
Origin: Lateral Aspect of lateral Pterygoid Plate 7 Tubercle of body of the Sphenoid
Insertion: mandibular Head & Articular Cartilage of Temporomandibular Joint
2. Branches of the maxillary artery- The maxillary artery is one of the terminal branches of the external carotid. It passes posterior to the neck of the mandible. It may pass anterior or posterior to the lateral pterygoid muscle.
Important branches of the maxillary artery (actually has 17 branches – many in nasal cavity) in the infratemporal fossa: Supplies muscles of mastication with named branches to the muscles
1. Middle meningeal Goes thru foramen spinosum
Very posterior & Short
2. Accessory meningeal (may not be present) Uses Foramen Ovale with V3 = blood supply to dura mater
3. Inferior alveolar Enter mandibular canal, give off dental branches & exit as mental artery
4. Deep temporals Blood supply to temporalis (important land marks in dissection)
5. Posterior superior alveolar Pierce Maxilla to supply maxillary teeth
The maxillary artery leaves the infratemporal fossa to enter the posterior aspect of the nasal cavity.
3. Pterygoid plexus of veins- this important very dense plexus of veins lies deep to the temporalis muscle and drains to maxillary. This plexus can drain to orbital veins, superficial face, & pharynx. It receives veins from orbit, face, & pharynx.
May drain to cavernous sinus by very small veins
4. Branches of the mandibular nerve- all of the nerves in the infratemporal region are branches of the mandibular nerve (CN V3) except for the chorda tympani. The mandibular nerve has both motor and sensory fibers. Goes through the Foramen Ovale into Infratemporal fossa where it divides into its nerves
Motor branches: For Skeletal Muscles derived from 1st pharyngeal arch
1. To the muscles of mastication
A. Nerve to Temporalis
B. Nerve to Masseter
C. Nerve to Medial Pterygoid
D. Nerve to Lateral Pterygoid
2. To the tensor muscles
E. Tensor Veli Palatinie important muscle of the soft palate
F. Tensor Tympani muscle of middle ear = Dampens loud sounds
Buccinator = Muscle of facial expression (Innervation = CN VII)
Fills your cheek
Holds resistance for oral cavity
Example = straw, baby suckling, trumpet players
Otic ganglion(parasympathetic ganglion) involved in the postganglionic innervation of the parotid gland.
Chorda tympani- Branch of the facial nerve that joins the lingual nerve in the infratemporal fossa and carries taste fibers from the anterior 2/3 of the tongue as well as preganglionic parasympathetic fibers to the submandibular and sublingual glands.