The pterygopalatine fossa is a small pyramidal space located behind the maxilla and below the orbit. It contains the maxillary nerve, pterygopalatine ganglion, maxillary artery and veins. The fossa communicates with several areas through canals including the orbit, nasal cavity, infratemporal fossa and middle cranial fossa. It is an important distribution center for branches of the maxillary nerve and artery.

1. Pterygopalatine fossa
for 2nd year MBBS, by Dr M Idris Siddiqui
It is a complex small, pyramidal space,
below & behind the apex of orbit,
found deep within the face.
Syn: fossa pterygopalatina [NA], Bichat's fossa,
pterygomaxillary fossa, sphenomaxillary fossa.

3. Pterygoid
process

4. maxilla

5. Location
 It is located posterior to the maxilla,
inferior to the apex of the orbit, and
immediately lateral to the lateral wall of
the nose, between the pterygoid process,
the maxilla, and the palatine bone.

6. Boundaries
 Anterior: The posterior surface of the maxilla
 Posterior: The base of the lateral pterygoid plate
and the opening of the foramen rotundum and
pterygoid canal
 Inferior: The junction of the palatine perpendicular
plate and the maxilla
 Superior: The greater wing of the sphenoid and
the inferior orbital fissure
 Medial: The perpendicular plate of the palatine
bone and the sphenopalatine foramen
 Lateral: The pterygomaxillary fissure

8. The pterygopalatine fossa is a small pyramidal space housing the
pterygopalatine ganglion. The fossa is seen through the pterygomaxillary
fissure between the pterygoid process and the maxilla.

11. The fossa has been exposed through the floor of the orbit and maxillary sinus.
The foramen rotundum, pterygoid canal, and pharyngeal canal are openings in the
posterior wall of the pterygopalatine fossa.

13.  The pterygopalatine fossa is a major
distributing center for branches of the maxillary
nerve and the pterygopalatine (third) part of
the maxillary artery.
 It is located between, and has communications
with, the infratemporal fossa, nasal cavity,
orbit, middle cranial fossa, pharyngeal vault,
maxillary sinus, and oral cavity (palate).
 Its contents are
 The maxillary nerve (CN V2),
 The parasympathetic pterygopalatine ganglion,
 The third part of the maxillary artery and
 Accompanying veins, and
 A surrounding fatty matrix.

18. Contents
 The major structures of the fossa are
 The maxillary artery,
 Accompanying veins
 Pterygopalatine ganglion, and
 Maxillary nerve.
 Fat .

19. Communications
 It has a space with multiple entrances and exits.
 Through its many complex and small bony passages, important
vessels and nerves communicate with
 The oral cavity,
 Nasal cavity,
 Orbit,
 Cranial cavity,
 Infratemporal fossa, and
 Anterior surface of the face.
In general, the vascular structures of the pterygopalatine
fossa enter it through its lateral wall; the nerves of the
fossa enter it posteriorly.

20. The pterygopalatine fossa communicates
 Laterally: with the infratemporal fossa through
the pterygomaxillary fissure.
 Medially: with the nasal cavity through the
sphenopalatine foramen.
 Anterosuperiorly: with the orbit through the
inferior orbital fissure.
 Posterosuperiorly: with the middle cranial fossa
through the foramen rotundum and
pterygoid canal.

21. Direction Passage Connection
Posteriorly foramen rotundum middle cranial fossa
Posteriorly pterygoid canal (Vidian)
middle cranial
fossa, foramen lacerum
Posteriorly
palatovaginal
canal (pharyngeal)
nasal cavity/nasopharynx
Anteriorly inferior orbital fissure orbit
Medially sphenopalatine foramen nasal cavity
Laterally pterygomaxillary fissure infratemporal fossa
Inferiorly
greater palatine
canal (pterygopalatine)
oral cavity, lesser palatine
canals
Passages
The following passages connect the fossa with other parts of the skull:

25. Pterygopalatine Part of the Maxillary Artery
 The maxillary artery, a terminal branch of the
external carotid artery, passes anteriorly and
traverses the infratemporal fossa.
 It passes over the lateral pterygoid muscle and
enters the pterygopalatine fossa. The
pterygopalatine part of the maxillary artery, its
third part, passes through the pterygomaxillary
fissure and enters the pterygopalatine fossa,
where it lies anterior to the pterygopalatine
ganglion. The artery gives rise to branches that
accompany all nerves in the fossa with the same
names.

28. The maxillary artery
 The terminal part of the maxillary artery branches within the nose
to supply
 The conchae and nasal septum (by the sphenopalatine artery),
 Palate (by the greater and lesser palatine arteries), and
 Nasopharynx (by the pharyngeal artery).
 The sphenopalatine artery branches off of the maxillary artery
within the confines of the pterygopalatine fossa, then travels
medially through the sphenopalatine foramen to reach the interior
of the nose.
 The greater palatine artery departs the maxillary artery within the
fossa as well and descends through the greater palatine canal to
reach the palate.
 The lesser palatine arteries, supplying the soft palate, are actually
branches of the greater palatine arteries, supplying the hard
palate.
 The small pharyngeal artery leaves the maxillary artery within the
pterygopalatine fossa and enters a small passage, known as the
palatovaginal canal, to emerge into the nasopharynx, which it
supplies with blood.

29. Maxillary Nerve
 The maxillary nerve enters the pterygopalatine fossa
through the foramen rotundum and runs anterolaterally
in the posterior part of the fossa. Within the
pterygopalatine fossa, the maxillary nerve gives off the
zygomatic nerve, which divides into zygomaticofacial
and zygomaticotemporal nerves.
 These nerves emerge from the zygomatic bone through cranial
foramina of the same name and supply general sensation to the lateral
region of the cheek and temple. The zygomaticotemporal nerve also
gives rise to a communicating branch, which conveys parasympathetic
secretomotor fibers to the lacrimal gland by way of the heretofore
purely sensory lacrimal nerve from CN V1.
 While in the pterygopalatine fossa, the maxillary nerve
also gives off the two pterygopalatine nerves that
suspend the parasympathetic pterygopalatine ganglion
in the superior part of the pterygopalatine fossaThe
maxillary nerve leaves the pterygopalatine fossa
through the inferior orbital fissure, after which it is
known as the infraorbital nerve.

30. The pterygopalatine ganglion
 The pterygopalatine ganglion is a
parasympathetic ganglion, one of four
found in the head and neck region.
Postganglionic axons from the ganglion
travel through intricate pathways to
innervate the lacrimal gland and, to a
lesser degree, the minor salivary glands of
the soft palate.

31. The nerve of the pterygoid canal
 In addition to the maxillary nerve, the
nerve of the pterygoid canal also enters
the pterygopalatine fossa through the
opening of the pterygoid canal in its
posterior wall.
 This nerve consists of axons from
 (1) the greater petrosal nerve, composed of
preganglionic parasympathetic axons derived from
the facial nerve, and
 (2) the deep petrosal nerve, a collection of
postganglionic sympathetic axons derived from the
internal carotid plexus.

33. Transantral Approach to the Pterygopalatine Fossa
 Surgical access to the deeply placed
pterygopalatine fossa is gained through the
maxillary sinus. After elevating the upper lip, the
maxillary gingiva and anterior wall of the sinus
are transversed to enter the sinus.
 The posterior wall is then chipped away as
needed to open the anterior wall of the
pterygopalatine fossa. In the case of chronic
epistaxis (nosebleed), the third part of the
maxillary artery may be ligated in the fossa to
control the bleeding.