The infratemporal fossa is a space deep to the ramus of the mandible that contains nerves, arteries and muscles. It communicates with the temporal fossa and pterygopalatine fossa. The mandibular nerve passes through the foramen ovale and gives off motor and sensory branches that innervate muscles of mastication and sensation to the face. The maxillary artery passes through supplying branches. The pterygoid venous plexus drains the area.

1. INFRATEMPORAL FOSSA
Dr. Mohammed Mahmoud Mosaed

2. INFRATEMPORAL FOSSA
• Site: it lies deep to the
ramus of the mandible.
• Communications: It
communicates with the
temporal fossa deep to the
zygomatic arch and the
pterygopalatine fossa
through the
pterygomaxillary fissure

3. Boundaries
• The infratemporal fossa has a roof, and
lateral and medial walls, and is open to the
neck posteroinferiorly, i.e. the fossa has no
anatomical floor
• The roof is formed by the infratemporal
surfaces of the temporal bone and of the
greater wing of the sphenoid, and contains
the foramena ovale and spinosum and the
petrotympanic fissure: it is open superiorly to
the temporal fossa

4. Boundaries
• The medial wall is formed anteriorly by the
lateral pterygoid plate of the pterygoid process
of the sphenoid, and more postero-medially by
the pharynx and tensor and levator veli
palatini. It contains the pterygomaxillary fissure
across which structures pass between the
infratemporal and pterygopalatine fossae
• The lateral wall is formed by the medial
surface of the ramus of the mandible.

5. Contents
• The major structures that occupy the
infratemporal fossa are:
– The lateral and medial pterygoid muscles,
– The mandibular division of the trigeminal nerve,
– The chorda tympani branch of the facial nerve,
– The otic parasympathetic ganglion,
– The maxillary artery
– The pterygoid venous plexus

7. • The mandibular nerve is the largest of the three divisions of the
trigeminal nerve.
• Mandibular nerve is both motor and sensory.
• It carries :
• General sensation from the teeth and gingivae of the mandible,
the anterior two-thirds of the tongue, mucosa on the floor of
the oral cavity, the lower lip, skin over the temple and lower
face, and part of the cranial dura mater.
• Motor innervation
• to the muscles of mastication, mylohyoid and anterior belly of
digastric muscle
• to one of the muscles (tensor tympani) in the middle ear, and
one of the muscles of the soft palate (tensor veli palatini).
Mandibular nerve

8. • All branches of the mandibular nerve originate in the
infratemporal fossa.
• The sensory part of the mandibular nerve
• originates from the trigeminal ganglion in the middle
cranial fossa:
• It passes vertically through the foramen ovale and
enters the infratemporal fossa between the tensor
veli palatini muscle and the upper head of the lateral
pterygoid muscle;
• The small motor root of the trigeminal nerve
• passes medial to the trigeminal ganglion in the cranial
cavity, then passes through the foramen ovale and
immediately joins the sensory part of the mandibular
nerve.

11. • Branches:
• Soon after the sensory and motor roots join, the
mandibular nerve gives rise to a small meningeal
branch and nerve to medial pterygoid, and then
divides into anterior and posterior trunks:
• Branches from the anterior trunk are the buccal,
masseteric, and deep temporal nerves, and the nerve
to lateral pterygoid, all of which are motor nerves,
except the buccal nerve which is sensory.
• Branches from the posterior trunk are the
auriculotemporal, lingual, and inferior alveolar nerves,
all of which, are sensory nerves except nerve to
mylohyoid that branches from the inferior alveolar
nerve which is motor

13. Branches of the trunk of mandibular
nerve
• Meningeal branch (nervous spinosus)
• Ascends with the middle meningeal artery and re-
enter the cranial cavity through the foramen
spinosum.
• Nerve to medial pterygoid
• It enters and supplies the deep surface of the
medial pterygoid muscle.
• It has two small branches:
• One supplies the tensor veli palatini;
• One to the tensor tympani muscle

14. Branches of anterior division
• Buccal nerve
• A branch of the anterior trunk of the mandibular nerve. It is a sensory nerve,
• It passes laterally between the upper and lower heads of lateral pterygoid to the
anterior margin of the ramus of mandible.
• It continues into the cheek lateral to the buccinator muscle to supply general
sensory nerves to the adjacent skin and oral mucosa.
• Masseteric nerve
• It is a branch of the anterior trunk of the mandibular nerve.
• It passes through the mandibular notch to penetrate and supply the masseter
muscle.
• Deep temporal nerves
• Usually two in number, originate from the anterior trunk of the mandibular nerve.
They ascend in the temporal fossa and supply the temporalis muscle from its
deep surface
• Nerve to lateral pterygoid
• It originate directly as a branch from the anterior trunk of the mandibular nerve .
• It passes directly into the deep surface of the lateral pterygoid muscle.

15. Branches of the posterior division
• Auriculotemporal nerve
• Lingual nerve
• Inferior alveolar nerve

16. Auriculotemporal nerve
• It is the first branch of the posterior division of the
mandibular nerve and originates as two roots, which
pass posteriorly around the middle meningeal artery.
• It curves laterally around the neck of mandible and
then ascends deep to the parotid gland between the
temporomandibular joint and ear.
• It carry general sensation from skin over a large area
of the temple.
• Sensory innervation of the external ear, the external
auditory meatus, tympanic membrane, and
temporomandibular joint.
• It also delivers postganglionic parasympathetic nerves
from the glossopharyngeal nerve to the parotid gland.

17. Lingual nerve
• It is the sensory branch of the posterior trunk of the
mandibular nerve.
• The lingual nerve first descends between the tensor veli
palatini muscle and the lateral pterygoid muscle, where it is
joined by the chorda tympani nerve, and then descends
across the lateral surface of the medial pterygoid muscle to
enter the oral cavity.
• As the lingual nerve passes on the medial surface of the
mandible immediately inferior to the last molar tooth.
• It is in danger when operating on the molar teeth and
gingivae.
• The lingual nerve passes into the tongue on the lateral
surface of the hyoglossus muscle where it is attached to the
submandibular ganglion.

18. • The lingual nerve carries general sensation from
the anterior two-thirds of the tongue, oral
mucosa on the floor of the oral cavity, and lingual
gingivae associated with the lower teeth.
• The lingual nerve is joined by the chorda tympani
branch of the facial nerve, which carries:
• Taste from the anterior two-thirds of the tongue.
• Parasympathetic fibers to all salivary glands
below the level of the oral fissure.

22. Inferior alveolar nerve
• It is a major sensory branch of the mandibular nerve.
• It innervates all lower teeth and gingivae, the mucosa and
skin of the lower lip and skin of the chin.
• It has one motor branch, which innervates the mylohyoid
muscle and the anterior belly of the digastric muscle.
• It descends and then enters the mandibular canal through
the mandibular foramen.
• Just before entering the mandibular foramen, it gives the
nerve to mylohyoid, to innervate the mylohyoid muscle and
the anterior belly of the digastric muscle.
• The inferior alveolar nerve passes anteriorly within the
mandibular canal of the lower jaw.
• It supplies molar and second premolar teeth and associated
labial gingivae, and then divides into its two terminal
branches: the incisive nerve and the mental nerve.

24. Chorda tympani nerve
• The chorda tympani originates from the facial
nerve.
• The chorda tympani carries taste from the anterior
two-thirds of the tongue and parasympathetic
innervation to all salivary glands below the level of
the oral fissure.
• It enters the infratemporal fossa, and joins the
lingual nerve.
• Preganglionic parasympathetic fibers carried in the
chorda tympani synapse in the submandibular
ganglion, which 'hangs off' the lingual nerve in the
floor of the oral cavity.

26. Lesser petrosal nerve
• The lesser petrosal nerve is a branch of the tympanic plexus in the middle
ear, which had its origin from a branch of the glossopharyngeal nerve.
• It carries mainly parasympathetic fibers for the parotid gland.
• The tympanic nerve which is branch from the glossopharyngeal nerve
enters the middle ear to participates in the formation of the tympanic
plexus on the promontory of the middle ear.
• The lesser petrosal nerve is a branch of this plexus.
• The lesser petrosal nerve contains mainly preganglionic parasympathetic
fibers.
• It leaves the middle ear and enters the middle cranial fossa through a
small opening on the anterior surface of the petrous part of the temporal
bone.
• The lesser petrosal nerve then passes through the foramen ovale with the
mandibular nerve.
• In the infratemporal fossa it synapse in the otic ganglion located on the
medial side of the mandibular nerve.
• Postganglionic parasympathetic fibers leave the otic ganglion and join the
auriculotemporal nerve, which carries them to the parotid gland.

28. • The maxillary artery is the largest branch of the
external carotid artery in the neck.
• The maxillary artery originates within the
substance of the parotid gland and then passes
forward, behind the neck of mandible
• It passes through the infratemporal fossa to enter
the pterygopalatine fossa by passing through the
pterygomaxillary fissure.
• This part of the vessel may pass either lateral or
medial to the lower head of lateral pterygoid.
Maxillary artery

30. • The first part of the maxillary artery (from the neck of
mandible to lateral pterygeoid muscle) gives:
• The middle meningeal artery
• inferior alveolar arteries
• Smaller branches: deep auricular, anterior tympanic, and
accessory meningeal.
• The second part of the maxillary artery (the part related to
the lateral pterygoid muscle) gives:
• Deep temporal, masseteric, buccal, and pterygoid branches.
• The third part of the maxillary artery is in the
pterygopalatine fossa and gives:
• The posterior superior alveolar. Infra-orbital, Greater
palatine, Pharyngeal and Sphenopalatine arteries and The
artery of the pterygoid canal.
Branches

31. • Middle meningeal artery
• Passes through the foramen spinosum to enter the
cranial cavity.
• It passes between the two roots of the
auriculotemporal nerve at their origin from the
mandibular nerve.
• Within the cranial cavity, it travel in the periosteal
(outer) layer of dura mater, they can be damaged
by lateral blows to the head.
• When the vessels are torn, result in an extradural
hematoma.

32. • Inferior alveolar artery
• It enter the mandibular foramen and canal.
• It is distributed to lower teeth, and the buccal gingivae,
chin and lower lip.
• Before entering the mandible, it gives mylohyoid branch
to mylohyoid.

33. Branches from the second part
• Deep temporal arteries, usually two in number,
supply the temporalis muscle in the temporal
fossa.
• Numerous pterygoid arteries supply the pterygoid
muscles.
• The masseteric artery, passes laterally through
the mandibular notch to supply the masseter
muscle.
• The buccal artery supplies skin, muscle, and oral
mucosa of the cheek.

34. Third part of the maxillary artery
• It is the part of the maxillary artery in the
pterygopalatine fossa
• Branches of the maxillary artery include;
• The posterior superior alveolar.
• Infra-orbital.
• Greater palatine.
• Pharyngeal.
• Sphenopalatine arteries.
• The artery of the pterygoid canal.

35. • The pterygoid plexus is a network of veins around
lateral pterygoid muscle.
• Veins correspond to arteries branching from the
maxillary artery in the infratemporal fossa and
pterygopalatine fossa connect with the pterygoid
plexus. These tributary veins include those that
drain the nasal cavity, roof and lateral wall of the
oral cavity, all teeth, muscles of the infratemporal
fossa, paranasal sinuses, and nasopharynx.
Pterygoid plexus

36. • In addition, the inferior ophthalmic vein from
the orbit drains through the inferior orbital
fissure into the pterygoid plexus.
• Emissary veins connect the pterygoid plexus in
the infratemporal fossa to the cavernous sinus
through the foramen ovale.
• The pterygoid plexus connects anteriorly, via a
deep facial vein, with the facial vein on the
face.

38. The pterygopalatine fossa
• The pterygopalatine fossa is a small space behind
and below the orbital cavity.
• It communicates:
• Laterally with the infratemporal fossa through the
pterygomaxillary fissure,
• Medially with the nasal cavity through the
sphenopalatine foramen,
• Superiorly with the skull through the foramen
rotundum,
• Anteriorly with the orbit through the inferior
orbital fissure

40. Boundaries of pterygopalatine fossa
• Anterior: superomedial part of the infratemporal
surface of maxilla
• Posterior: root of the pterygoid process and
adjoining anterior surface of the greater wing of
sphenoid bone
• Medial: perpendicular plate of the palatine bone
and its orbital and sphenoidal processes
• Lateral: pterygomaxillary fissure
• Inferior: part of the floor is formed by the
pyramidal process of the palatine bone.

41. Contents
Contents of pterygopalatine fossa:
• 1. The pterygopalatine ganglion suspended by
nerve roots from the maxillary nerve
• 2. The third part of the maxillary artery
• 3. The maxillary nerve (the second division of the
trigeminal nerve),
• 4. The nerve of the pterygoid canal, a combination
of the greater petrosal nerve (preganglionic
parasympathetic) and the deep petrosal nerve
(postganglionic sympathetic).

42. Pterygopalatine Ganglion
• The pterygopalatine ganglion is a parasympathetic
ganglion, which is suspended from the maxillary
nerve in the pterygopalatine fossa. It is
secretomotor to the lacrimal and nasal glands.
• Branches
• Orbital branches, which enter the orbit through
the inferior orbital fissure
• Greater and lesser palatine nerves, which supply
the palate, the tonsil, and the nasal cavity
• Pharyngeal branch, which supplies the roof of the
nasopharynx