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Anatomy

Dr .Nawfal

Infratemoporal fossa

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Veins are similar to arteries.

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Nerve supply is identical to the submandibular gland.

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The infratemporal fossa:

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This is the space which lies between the pharynx medially & the angle of the
mandible laterally.

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Boundaries:

-Anteriorly: the back of maxilla & pterygoid process
-Posteriorly: the styloid apparatus laterally & the carotid sheath medially
-Laterally: the ramus & angle of the mandible
-Medially: the wall of the pharynx & medial pterygoid plate
-Superiorly:  the  floor  of  the  middle  cranial  fossa  formed  by  the  greater  wing  of
sphenoid  &  squamous  temporal,  the  roof  ends  laterally  in  the  infratemporal  crest
which leads to the temporal fossa
-Inferiorly:  the  ITF  is  continuous  with  the  neck  at  the  retropharyngeal  space  which
leads down through the superior into the posterior mediastinum.

Head & Neck Dr. Nawfal K. Al-Hadithi

Contents:

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Muscles:

1- Lateral pterygoid
2-Medial pterygoid

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Arteries:

Maxillary artery.

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Veins:

Pterygoid venous plexus.

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Nerves:

1- Mandibular nerve.
2- Otic ganglion.
The lateral pterygoid muscle:

This muscle occupies the upper part of
the ITF

I t s f i b e r s a r e d i r e c t e d a l m o s t
horizontally from the front backwards

Origin:
Upper  head  “small”:  infratemporal  surface  of
the greater wing of sphenoid
Lower  head  “large”:  lateral  surface  of  the
lateral pterygoid plate
Insertion:
Upper head: Disc & capsule of TMJ
Lower head: Pterygoid pit
Nerve supply:
Nerve  to  lateral  pterygoid,  a  branch  of  the
anterior division of mandibular n.
Action:

It is a masticatory muscle, it starts
opening the mouth

Lateral pterygoid is a protractor of the
mandible too.

The upper head pulls the articular disc &
anterior part of the capsule anteriorly
preventing its nipping by the bone.
The medial pterygoid muscle:

This muscle is seen at a lower level in
the fossa

Fibers are arranged in a posterior,
inferior & lateral direction.

Origin:
Superficial head “small”: maxillary tuberosity
Deep head “large”: medial surface of lateral
pterygoid plate
Insertion:

Head & Neck Dr. Nawfal K. Al-Hadithi

Articular disc

The two heads are inserted on the deep surface
of the angle of the mandible almost   alike the
insertion of masseter on the lateral surface
Nerve supply:
Nerve  to  medial  pterygoid,  a  direct  branch
from  the  main  trunk  of  the  mandibular  nerve.
This nerve has two main characteristics:
1-It  enters  the  otic  ganglion  without  relay  of
its fibers in it.
2-It  supplies  tensor  palati  &  tensor  tympani
muscles too.
Action:
- Closes the mouth together with masseter.
-  It  is  a  grinding  muscle,  by  the  lateral
orientation  of  its  fibers  the  muscle  pulls  the
mandible towards the opposite side

The maxillary artery:

The larger of the two terminal branches of the ECA

Enters the ITF by passing deep to the mandibular neck, between it & the
sphenomandibular ligament, together with the maxillary veins & the
auriculotemporal nerve

It possesses a tortuous course passing usually (in 2/3 of individuals) lateral to
lat. pterygoid according to which the artery is divided into three parts:

1- First “mandibular” part: before reaching the lateral pterygoid, it gives 5 branches
each enters a bone.

Head & Neck Dr. Nawfal K. Al-Hadithi

2-  Second  “pterygoid”  part:  lies  along  (medial  or  lateral)  to  the  lateral  pterygoid,  it
gives 5 branches to soft tissue, 4 of them to the masticatory muscles & the 5th is the
buccal.
3-Third  “pterygopalatine”  part:  which  enters  the  pterygopalatine  fossa  through  the
pterygomaxillary  fissure  &  gives  5  branches  that  accompany  those  of  the
pterygopalatine ganglion & each branch of maxillary nerve.
Branches of the first part:
1- Deep auricular artery:

Penetrates the external auditory meatus

Gives a branch to the TM joint

Supplies the skin of the meatus & outer surface of the tympanic membrane.

2- Anterior tympanic artery:
- Ascends parallel to the deep auricular artery
-  Enters  the  tympanic  cavity  through  petrotympanic  fissure  together  with  chorda
tympani
- Supplies the tympanic cavity & the inner surface of the tympanic membrane
3- Middle meningeal artery:
- Is the prime artery of the cranial dura
- Ascends upward enclosed by the two roots of
the  auriculotemporal  nerve,  to  enter  the  MCF
through foramen spinosum
-  At  the  floor  of  the  MCF  it  lies  between  the
greater wing of sphenoid & dura mater
- After a short course it divides into anterior &
posterior divisions:
1-anterior;  continues  grooving  the  sphenoid
then  it  reaches  the  parietal  bone  which  it
grooves  near  its  anterior  border  as  the  artery
ascends to the vertex.
2-posterior;  goes  back  to  groove  the  squamous  temporal  &  ascends  to  the  parietal
bone  near  its  posterior  border,  then  along  the  superior  sagittal  sinus  to  reach  the
occipital bone.
4- Accessory meningeal artery:

Frequently a branch of the middle meningeal

Supplies some extracranial structures

Enters foramen ovale to supply the trigeminal ganglion & adjacent dura mater

5- Inferior alveolar (dental) artery:

Descends to the mandibular foramen behind the accompanying nerve

Before it enters the foramen, the artery gives two branches:

1-lingual; with the lingual nerve !! (There are two one from inferior alveolar artery
and the second is a direct branch from ECA)
2-mylohoid; with mylohyoid nerve, piercing the sphenomandibular ligament &
supplies the muscle

In the bone, the artery supplies the teeth in a manner similar to nerve supply

Terminates near the mental foramen by dividing into incisive & mental arteries

Head & Neck Dr. Nawfal K. Al-Hadithi

Branches from the second part:
1- Masseteric artery:

Enters the mandibular notch

Supplies masseter & anastomoses with the transverse facial artery

2- Anterior & posterior deep temporal arteries:

Accompany the corresponding nerves to temporalis

The accompanying veins impress the bone in the temporal fossa

3 & 4- Pterygoid branches:
- Supply the two pterygoids
5- Buccal artery:

Accompanies the long buccal nerve

Goes to the region of buccinator

Supplies skin of the cheek & mucous membranes of the mouth

Branches from the third part:
A) Branches which accompany those of the pterygopaltine ganglion:
1-Posterior superior lateral nasal arteries.
2- Greater palatine artery.
3- Lesser palatine arteries.
4- Nasopalatine (anterior palatine) artery.
5- Pharyngeal artery.
B) Branches accompanying the maxillary nerve branches:
1- Posterior superior alveolar artery.
2- Infraorbital artery.
3- Anterior superior alveolar artery.

Head & Neck Dr. Nawfal K. Al-Hadithi

Pterygoid venous plexus:

A plexus of veins which lie in & around the lateral pterygoid muscle

It receives tributaries corresponding to those of the maxillary artery branches

It is drained by two maxillary veins which leave the fossa deep to the neck of
the mandible to the parotid in order to join the superficial temporal vein
forming the retromandibular vein.

Head & Neck Dr. Nawfal K. Al-Hadithi

Applied anatomy:
*Stagnation of venous blood in the plexus initiates reflex contraction of lateral
pterygoid muscle producing yawning.
*The plexus is connected to:
1-Anterior facial vein by two ways:
Via the infraorbital v. – supraorbital - angular
Via the deep facial v. which lies between masseter & buccinator.
2- Cavernous sinus by two ways:

A. Via the infraorbital – supraorbital - cavernous
B. Via an emissary vein which enters foramen ovale

These  two  connections  of  the  anterior  facial  vein  to  the  cavernous  sinus  facilitates
transmission of infection from the face to the sinus therefore the area between these
two connections (mask area) is regarded as dangerous area.
The Mandibular nerve:
*The largest of the 3 divisions of the trigeminal nerve
*It takes all the motor component of V nerve
*Enters the ITF from its roof through foramen ovale
*It  lies  very  deep  in  the  fossa  near  the  medial  wall  (pharyngeal  wall)  on  the  lateral
surface of tensor veli palatini
*It is closely related in this position to the otic ganglion
*It  is  divided  into  anterior  &  posterior  divisions,  the  anterior  is  the  smaller  &  is
almost totally motor & the posterior is the larger & is almost completely sensory

*Branches:
A)From the trunk: - Meningeal n.
- Nerve to medial pterygoid
B)From the anterior division: - Masseteric n.
- Deep temporal nn. “MOTOR”
- Pterygoid n.
- Long buccal n. “SENSORY”
C)From the posterior division: - Auriculotemporal n.
- Lingual n. “SENSORY”
- Inferior alveolar n. “MIXED”
From the trunk:
1-Meningeal nerve:

This branch is given just below the skull base

Re-enters the cranium through foramen spinosum to supply dura mater in the
floor of the MCF

2-Nerve to medial pterygoid:

From the trunk of Vc, this nerve is given to medial pterygoid muscle

It passes through the otic ganglion without functional relation to it

It supplies also tensor veli palatini by a branch which enters it near its origin
and tensor tympani by a branch which enters the cartilage of the auditory tube.

From the anterior division:

Head & Neck Dr. Nawfal K. Al-Hadithi

1-Masseteric nerve:

This branch is given from the anterior division of Vc.

Passes through the mandibular notch to enter the deep surface of masseter

2-Deep temporal nerves:

2-3 nerves arise from the anterior division of Vc

After passing in the roof of ITF they enter the temporal fossa by passing over
the infratemporal crest

On the deep surface of temporalis, these nerves pass & supply the muscle

3-Lateral pterygoid nerve:

This branch is given from the anterior division of Vc.

Supplies lateral pterygoid muscle by entering its deep surface

4-Long buccal nerve:

Is the only sensory branch in the anterior division

Following temporalis tendon, the nerve passes in the direction of buccinator
muscle accompanied by a branch from the maxillary artery

Over buccinator it divides to supply the overlying skin of the cheek &
undelying mucous membranes

Should be differentiated from the buccal branch of facial nerve which comes
from a more superficial plane but forms a plexus with this nerve over
buccinator

Head & Neck Dr. Nawfal K. Al-Hadithi

Branches of Vc

From the trunk and

anterior division

From the posterior division:
1- Auriculotemporal nerve:
- Arises by two roots embracing the origin of the middle meningeal a.
-Passes deep to LPt. muscle in a posterior direction to leave the ITF between the neck
of the mandible & sphenomandibular lig. with the maxillary vessels
-It passes in the upper part of the parotid gland
-It  is  accompanied  by  postganglionic  fibers  from  the  otic  ganglion  to  supply  the
parotid  gland  with  secretomotor  supply,  the  preganglionic  fibers  are  brought  to  the
ganglion  via  the  lesser  petrosal  branch  of  the  IX  nerve  from  the  inferior  salivatory
nucleus.
-Branches:
1-Glandular; sensory fibers to the parotid
2-Auricular; to the external acoustic meatus & upper lateral ½ of the auricle
3-Articular; to the TM joint
4-Temporal; to the hairy part of the temple.
2- Lingual nerve:
-Passes on the lateral side of MPt. muscle anterior to the inferior alveolar nerve.
-Grooves  the  medial  aspect  of  the  mandible  at  the  mandibular  attachment  of  the
pterygomanibular raphe just behind mylohyoid
-Passes  forward  on  the  lateral  surface  of  hyoglossus  in  a  curve  which  descends  &
then ascends across the submandibular duct
-In  this  region  it  hangs  the  submandibular  ganglion  from  which  it  takes
postganglionic  secretomotor  fibers  to  the  submandibular  &  sublingual  glands.  The
preganglionic of these came together with taste fibers by chorda tympani nerve which
has joined the lingual nerve high in the ITF near the skull base.
-It supplies:
1-Ordinary sensation to the anterior 2/3 of the tongue, floor of the mouth & lingual
aspect of the lower gingiva.
2-Secretomotor to submandibular & sublingual glands & minute glands of the floor
of the mouth “chorda tympani”.
3-Taste sensation to the anterior 2/3 of the tongue “chorda tympani”.

Head & Neck Dr. Nawfal K. Al-Hadithi

3-Inferior alveolar nerve:
-Passes  on  the  lateral  side  of  MPt.  muscle
between it & the mandible behind the lingual
nerve.
-It  takes  the  whole  remaining  part  of  the
motor component of the V nerve.
-Enters  the  mandibular  foramen  &  passes  in
the  inferior  alveolar  canal  accompanied  by
the inferior alveolar vessels.
-Branches:
1-Nerve  to  mylohyoid;  carries  all  the  motor
component  of  the  posterior  division,  given
just  before  the  nerve  enters  the  mandibular
foramen,  pierces  the  sphenomandibular  ligament  &  passes  forward  between  the
anterior belly of digastric & mylohyoid supplying both.
2-Inferior dental branches; to the pulps of the lower canine, premolars & molars.
3-Terminal branches; at the mental foramen the nerve divides into:
a)Incisive branch; for the lower incisors.
b)Mental branch; exits from the mental foramen & supplies skin & m.m of the lower
lip.

Head & Neck Dr. Nawfal K. Al-Hadithi

Branches of

posterior division

of Vc

Sphenomandibular ligament

Structures related to the ITF:
1-Pterygomandibular raphe:
-Intermuscular raphe extending from the pterygoid hamulus to the mandible.
-It  is  the  site  where  buccinator  &  superior  constrictor  muscles  interdigitate,
buccinator goes forward & superior constrictor backward.
2-Pterygomaxillary ligament:
-A  short  ligament  extending  between  the  pterygoid  hamulus  &  the  maxillary
tuberosity
-It will form an osseo-ligamentous canal for the passage of the tendon of tensor palati
muscle
3-Sphenomandibular ligament:
-A  wide  ligament  lies  superficial  to  medial  pterygoid  between  it  &  the  mandible,  it
extends between the spine of sphenoid & the lower border of the mandible near the
angle
-It embraces the maxillary vessels & auriculotemporal nerve between it & the neck of
the mandible

Head & Neck Dr. Nawfal K. Al-Hadithi

-It is pierced by nerve to mylohyoid & mylohoid artery

The orbit:
The bony orbit:

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The orbit is a four-sided pyramidal shape space whose base lies anterior & its
apex posterior

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The base is almost 3.5 X 4 cm & the depth is about 5 cm

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Medial walls are parallel to each other with a 2 cm
distance separating them

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Lateral walls diverge laterally at 45O from medial walls
thus the lateral walls are 90O at each other

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Orbital axis lies along the center of the orbit & both will
also be perpendicular on each other

Orbital margins:
The margins of the orbit are strong bones, they are even stronger
than its four walls

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Superior: supraorbital arch of the frontal bone

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Lateral: frontal process of zygomatic bone & zygomatic
process of frontal bone

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Inferior: zygomatic bone & maxilla

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Medial: frontal process of maxilla & maxillary process of frontal bone

Roof:
-Formed by orbital process of the frontal bone completed posteriorly by the lesser
wing of sphenoid

Head & Neck Dr. Nawfal K. Al-Hadithi

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