Anatomy lecture #: 9
Date: 8/3/2011 Tuesday
Dr. maher al-hadidi
Infratemporal fossa
TOPICS:
 boundaries
 contents
Last lecture we start talking about the infratemporal fossa, which is a
small space that is located medial to the ramus of the mandible.
 Boundaries:
1) Lateral wall formed by the ramus of the mandible.
2) Medial wallformed by the lateral pterygoid plate.
3) Roof (superior wall) formed by the inferior surface of greater
wing of sphenoid bone.
** It contains 2 foramina, foramen spinosum and foramen ovale.
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Behind foramen spinosum there is a spine which is called spine of
sphenoid.
4) Posterior wallformed by the styloid process and by the articular
process of the mandible (head & neck).
5) Anterior wall formed by the infratemporal part of maxilla.
** Which has posterior superior alveolar foramen for the posterior
superior alveolar artery and nerve, and tuberosity of maxilla.
{These 2 structures are important and we shouldn't forget them}

Between pterygoid and maxilla there is an opening
pterygomaxillary fissure (entrance of maxillary artery and other
important structures) that leads to pterygopalatine fossa.

Contents:
1) 3 muscles lateral pterygoid muscle , medial pterygoid muscle ,
temporalis muscle (narrowest part of it, this muscle is also located
in the temporal fossa)
2) 1 ligament sphenomandibular ligament extending from the spine of
sphenoid reaching the mandible.
3) 1 arterymaxillary artery.
4) 2 veinsmaxillary vein, pterygoid venous plexus.
5) 3 nervesmandibular nerve (v3) through foramen ovale.
Chorda tympani of the facial nerve (special sensation
for the taste buds of anterior 2/3 of the tongue) passing with lingual
nerve (general sensation)
Otic ganglion (parasympathetic secretomotor fibers to
Parotid gland)
*Note: all ganglia in head & neck are parasympathetic except the 3 pair
of sympathetic ganglia in the neck  superior, middle, inferior.
**To make things clear: trigeminal nerve originates from the pons,
trigeminal ganglion isn't inside the brain, it's outside the brain but inside
the skull, it's formed between the brain the cranial cavity on the lateral
side of cavernous sinus to give codes to it's 3 branches before division.
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Now we are going to talk about the contents in details starting with
the muscles:
After removing ramus of the mandible, coronoid process.
**lateral pterygoid muscle
It has 2 heads and it's triangular in shape.
*Origin: -upper headinfratemporal part of the greater wing of
sphenoid.
-lower head lateral (outer) surface of lateral pterygoid plate,
wedged between two heads of medial pterygoid muscle.
*Insertion: 1.pterygoid fossa of mandibular neck.
2. Temporomandibular joint (TMJ) capsule.
3. Articular disk of TMJ
(TMJ is 2 joints in one joint between the mandibular fossa of temporal
bone and the head of mandible, but there is no direct contact between
them due to the presence of the articular disk and that's why all the
synovial joints in our body are made of hyaline cartilage except the
articular disk it's a fibrocartilage excessive movement.
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The upper/superior joint which is between the upper surface of
articular disk and the mandibular fossa is for forward and backward
movements, lower/inferior joint which is between the lower surface of
articular disk and the head of mandible is for hinge movements up and
down.)
*Action: (DP) 1) Depression.
2) Protrusion, but mainly protrusion.
3) Pushes the mandible to the opposite side in side-toside movement.
**We can't do protrusion without depression in order to open our mouth
*Nerve supply: nerve to lateral pterygoid muscle from (V3)
**don’t forget that the nerve supply of all the muscles of mastication
through the motor branches of mandibular nerve.
** Lateral pterygoid muscle is sandwiched between the 2 heads of
medial pterygoid muscle.
**Medial pterygoid muscle
It has 2 heads.
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*Origin: -Deep (large) head medial (inner) surface of lateral
pterygoid plate.
-Superficial (small) head tuberosity of maxilla.
** SO there are 2 muscles attached to the lateral pterygoid plate from
outside  lateral pterygoid muscle and from inside  medial pterygoid
muscle. (Laterally: lateral pterygoid and medially: medial pterygoid.)
*Insertion: inner surface of the ramus and angle of mandible.
*Action: (ES) 1) Elevation.
2) Side-to-side movements of mandible.
**side-to-side movements are done by 2 muscles: medial and lateral
pterygoid muscles by alternating action between them.
(V3).
*Nerve supply: nerve to medial pterygoid from mandibular nerve
Now we will talk about maxillary artery:
**Maxillary artery
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** Common carotid arteryexternal carotid arterymaxillary artery
(large branch)
superficial temporal
artery.
** External carotid artery ascends upward opposite to the neck of the
mandible through the parotid gland.
**The maxillary artery is the largest branch of external carotid artery.
**Starts behind the neck of mandible, it passes medial and deep to the
neck of mandible.
**It passes external or internal to lateral pterygoid muscle but most of
the time externally, after crossing the lateral pterygoid it will disappear
by entering pterygomaxillary fissure to reach pterygopalatine fossa in
order to accompany it's twin maxillary nerve which innervates all the area
that is derived from maxillary process, and we also have pterygopalatine
ganglion that gives the maxillary nerve it's code as secretomotor
(parasympathetic) for the palate,mouth and nose.
**lateral pterygoid muscle divides the maxillary artery into 3 parts:
1) first(mandibular)partit gives 5 branches that pass through
spaces:
*inferior alveolar artery (enter through mandibular canal).
*middle meningeal artery (enter though foramen spinosum).
*accessory middle meningeal artery (enter through foramen
ovale).
*anterior tympanic artery (tympanic membrane).
*deep auricular artery (external auditory meatus).
2) Second (pterygoid) parton the outer and lateral surface of the
lateral pterygoid muscle, it gives mascular branches to medial and
lateral pterygoid muscle, masseter muscle and to temporalis
muscle.
Branches:
* deep temporal artery.
*lateral pterygoid artery.
*medial pterygoid artery.
*massetric artery.
*buccal artery.
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3) Third (pterygopalatine) part it gives branches to accompany the
branches of the maxillary nerve (v2).
** To make things clear: the origin of sympathetic fibers from thoracolumber region and then they ascend upward (because there is no ganglia
there) to reach structures of head &neck in the superior,middle,inferior
cervical sympathetic ganglia, these ganglia give branches of sympathetic
fibers around arteries and specially around the internal carotid artery
which enters the skull through the canal and cavernous sinus to the brain.
** Hay-fever: it is an allergic inflammation of the nasal airways
(mouth, nose, palatine), it affects the pterygopalatine ganglion commonly
caused by pollens of olives and treated by giving antihistaminic drugs.
"Wherever smart people work, doors are unlocked." =)
Done by:
Saba hawamdeh
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