this power point presentation is in detail about the anatomy of infratemporal fossa

1. Infratemporal fossa
Dr. Prathyusha PG ENT
Narayana Medical College
Nellore

2. • Introduction
• Boundaries
• Contents
• Applied anatomy

3. Introduction
• The infratemporal fossa is a complex and irregularly
shaped space, located deep to the masseter muscle
and the mandible.
• It acts as a conduit for many neurovascular structures
that travel between the cranial cavity and other
structures of the head.
• Tumors here present a surgical and diagnostic
challenge because of the complex anatomy and occult
nature of tumors harbored there.

4. Boundaries
• Anterior: the posterior surface of the maxilla
• Posterior: the styloid process, carotid sheath and
deep part of the parotid gland.
• Medial: lateral pterygoid plate of sphenoid
• Lateral: the ramus and coronoid process of the
mandible

8. The roof:
the infratemporal surface of the greater wing of the
sphenoid.

10. The infratemporal fossa has NO anatomical floor,
being continuous with tissue spaces in the neck.
The infratemporal fossa communicates with the
temporal fossa deep to the zygomatic arch

11. Contents
1. Lateral and medial pterygoid muscles.
2. Infratemporal pad of fat
3. Buccal lymph node
4. Mandibular nerve
5. Chorda tympani nerve
6. Maxillary artery
7. Pterygoid plexus of veins
8. Otic ganglion
9. Sphenomandibular ligament

12. Lateral pterygoid muscle
• largest component of the infratemporal fossa.
• This muscle has two heads, upper and lower.
• The upper head is smaller and arises from the
greater wing of sphenoid,
• while the larger lower head arises from the lateral
aspect of lateral pterygoid plate.
• The fibers of both these heads pass backwards to
be inserted into the neck of the mandible.

16. action
• to pull the head of the condyle out of
the mandibular fossa along the articular eminence
to protrude the mandible.
• Both lateral pterygoid muscles acts in helping lower
the mandible and open the jaw
• only muscle of mastication that assists in
depressing the mandible (opening the jaw).

17. Medial pterygoid muscle
• This muscle is the deepest of the four muscles of
mastication.
• It consists of two heads.
• The bulk of the muscle arises as a deep head from
the medial surface of the lateral pterygoid plate.
• Thus, the lateral pterygoid plate of the sphenoid
bone gives rise to both pterygoid muscles

18. • The smaller, superficial head of the medial pterygoid
muscle originates from
• the maxillary tuberosity and
• the neighbouring part of the palatine bone
• the fibres pass downwards and backwards to insert into
the roughened surface of the angle of the mandible on
its medial aspect.

19. action
• The medial pterygoid muscle is an elevator of the
mandible.
• It assists in lateral and protrusive movements.
• The medial pterygoid muscle is synergistic to the
masseter muscle.

20. Medial pterygoid muscle

22. 2. Infratemporal pad of fat:
• Lies between the temporalis muscle and the
infratemporal surface of maxilla.

23. Applied anatomy
• The pad of fat helps in outlining the posterior
antral tumor spread in CT scans.
• This infratemporal pad of fat continues with the
cheek pad of fat passing between the posterior wall
of maxilla and the zygoma.
• A mass present behind the maxilla always betrays
itself by displacing this pad of fat and causing a
puffy sweeling of the cheek (angiofibroma)

24. • Fat appears as a halo
around the tumor

25. 3. Buccal lymph node:
• Within this infratemporal pad of fat lies the buccal
lymph node.
• This node links the infratemporal lymphatics to the
facial lymphatics.

26. • Lymphatic drainage of the infratemporal fossa
region is into the submandibular and upper deep
cervical group of nodes

27. Applied anatomy
• enlargement of the nodes in this region should
alert the clinician to the possibility of infection
arising in the infratemporal fossa.
• This node should NEVER be left behind during
surgical resection of infratemporal fossa for
malignant tumors as it could commonly cause local
recurrence.

28. 4. Mandibular nerve
• penetrates the roof of the infratemporal fossa
through the foramen ovale.
• It gives rise to inferior alveolar and lingual nerve
branches.

31. Buccal branch of mandibular nerve
• Using the medial and lateral pterygoid muscles as
references
• the buccal branch of the mandibular nerve
accompanying buccal artery
• The nerve and artery usually pass between the two
heads of the lateral pterygoid muscle.

33. Other branches
• the lingual nerve
• inferior alveolar nerve
• These two nerves pass between the medial and
lateral pterygoid muscles.

34. Course of these nerves
• Distally, the inferior alveolar nerve enters the
mandibular foramen.
• The lingual nerve lies superior to the inferior
alveolar nerve and passes anteriorly to reach the
tongue.

36. • the inferior alveolar nerve, artery, and vein emerge
from the mental foramen as
• the mental nerve,
• mental artery,
• And mental vein .

39. Auriculo temporal nerve
• the auriculotemporal nerve has two roots that
encircle the middle meningeal artery.
• It carries sensory fibers from the skin of the
temporal region
• and postganglionic parasympathetic fibers from
the otic ganglion to the parotid gland.

41. 5. Chorda tympani
• chorda tympani nerve emerges from the
petrotympanic fissure
• passes anteriorly to join the lingual nerve
• This nerve carries special sensory taste fibers from
the anterior two-thirds of the tongue and
• preganglionic parasympathetic fibers to the
submandibular ganglion.

43. Maxillary artery
• it is divided into 3 parts in relation to lateral pterygoid
muscle
• First part : posterior to lateral pterygoid muscle
• Second part: within lateral pterygoid muscle
• Third part: anterior to lateral pterygoid muscle
( in pterygopalatine fossa through pterygomaxillary
fissure)

50. 6. Pterygoid venous plexus
• venous plexus of considerable size,
• situated between the temporalis
muscle and lateral pterygoid muscle,
• partly between the two pterygoid muscle

51. Veins contributing for plexus
• sphenopalatine
• middle meningeal
• deep temporal (anterior & posterior)
• pterygoid
• masseteric
• buccinator
• alveolar
• some palatine veins (palatine vein which divides into the
greater and lesser palatine v.)
• a branch which communicates with the ophthalmic vein
through the inferior orbital fissure
• infraorbital vein

56. • The pterygoid venous plexus communicates with the
cavernous sinus via two routes.
• One route is via emissary veins passing through the
foramen ovale, foramen spinosum.
• Another route is via the deep facial vein, which links
the pterygoid venous plexus with the facial vein.
• The facial vein connects with the superior ophthalmic
vein, which drains into the cavernous sinus.

57. Applied anatomy
• Due to its communication with the cavernous
sinus, infection of the superficial face may spread
to the cavernous sinus, causing cavernous sinus
thrombosis.
• These plexus could cause troublesome
bleeding during total maxillectomy surgery.

58. Cavernous sinus thrombosis
• Complications may
include
• edema of the eyelids,
conjunctivae of the
eyes,
• paralysis of cranial
nerves which course
through the cavernous
sinus.

59. 7. Otic ganglion
• located inferiorly to the foramen ovale,
• medial to the mandibular nerve
• preganglionic fibres from inferior salivatory nucleus
(associated with the glossopharyngeal nerve).
• Parasympathetic fibres travel within a branch of the
glossopharyngeal nerve, the lesser petrosal nerve, to
reach the otic ganglion.

60. • Post ganglionic fibres along the auriculotemporal nerve
(branch of the mandibular division of the trigeminal
nerve).
• provide secretomotor innervation to the parotid gland.
• Sympathetic fibres from the superior cervical chain
pass through the otic ganglion.
• They travel with the middle meningeal artery to
innervate the parotid gland.

63. 7. Sphenomandibular ligament
• a flat, thin band which is attached superiorly to the
spine of the sphenoid bone, and, becoming
broader as it descends,
• It is fixed to the lingula of the mandibular foramen.
• it limits distension of the mandible in an inferior
direction.
• It is slack when the TMJ is in closed position.
• It is taut as the condyle of the mandible is in front
of the temporomandibular ligament.

66. Communications
• The infratemporal fossa communicates
superiorly with middle cranial fossa by the
neurovascular formina like
• carotid canal,
• jugular foramen,
• foramen spinosum,
• foramen ovale
• foramen lacerum.

67. • Medially the infratemporal fossa communicates
with pterygopalatine fossa through the
pterygomaxillary fissure.
• With orbit through infra orbital fissure

69. • The pterygomaxillary fissure is contiguous with that
of the infraorbital fissure.
• The roof of the infratemporal fossa is open to the
temporal fossa lateral to the greater wing of
sphenoid, deep to the zygomatic arch.

72. Applied anatomy
• Benign tumors involving the infratemporal fossa
always respect these boundaries
• They expand in the direction of soft tissue planes,
or follow preexistant pathways and foramen
described above.

73. • Maxillofacial trauma , maxillary osteotomies, have
the potential to disrupt the soft tissue contents of
the infratemporal fossa
• These fractures frequently extend to involve the
bones immediately adjacent to them

74. • Infection of the infratemporal fossa is most
commonly associated with a pericoronitis of
mandibular third molar tooth
• dental abscess of this tooth, or as a result of
infection following tooth extraction
• Rarely, it may result from an infected needle used
during an inferior alveolar nerve block.

76. • Infection of the infratemporal region may be
secondary due to spread from an adjacent infected
tissue space.
• The main symptom is trismus (though a common
symptom of parapharyngeal abscess)generally
affecting the medial pterygoid muscle
• Externally there is usually little evidence of tissue
swelling.

77. • Spread of infection from the infratemporal fossa
region to involve the buccal space is characterised
by the presence of a swelling of the cheek
• The swelling is bounded above by the zygomatic
arch and below by the lower border of the
mandible, both landmarks being palpable.

78. • Infection from the infratemporal fossa may spread
• directly around the back of the maxillary tuberosity
• into the orbit via the inferior orbital fissure.
• This may result in cavernous sinus thrombosis
• Once in the orbit, further direct spread of infection
through the superior orbital fissure will gain
entrance into the cranial cavity.

79. • Spread from the infratemporal fossa via the
pterygomaxillary fissure may also involve the
pterygopalatine fossa,
• which contains the maxillary nerve,
• maxillary artery
• pterygopalatine ganglion

80. • From the pterygopalatine fossa a number of small
canals lead into
• nose,
• pharynx
• palate.

81. Applied anatomy
• Tumors of the infratemporal fossa can be described
as
• primary,
• secondary or metastatic.
• Adenoid cystic carcinoma, adenocarcinoma, and
squamous cell carcinoma are common
• nasopharyngeal fibroma frequently found in
benign lesions..

82. • it is usually involved by tumors extending from
areas such as
• the paranasal sinuses,
• middle cranial fossa,
• nasopharynx,
• parotid,
• external auditory canal.

83. • Primary tumors of the infratemporal fossa are seen less
frequently and metastasis to this area is extremely rare.
• Due to it’s concealed location, tumors often present
late.
• Clinical signs and symptoms are insidious and are
frequently attributed to other structures or disease.
• In addition, surgical planning is confounded by the
close proximity to intracranial structures, the orbit,
sinuses, and the nasopharynx

84. Take home message
• Numerous structures in this deep irregular space expects us
to be anatomically oriented
• Potential communication to cavernous sinus, middle cranial
fossa and orbit makes this area a potential high risk space
• Highly vascular area due to pterygoid plexus and maxillary
artery warns surgeons to be alert to prevent bleeding
• Appearance of infections in other tissue spaces like orbit,
pterygopalatine fossa, and in the maxillary antrum should
prompt a primary site in infratemporal fossa
• Due to its concealed location tumours often present late

85. Bibliography
• Surgical Anatomy of the Infratemporal Fossa, John D.Langdon,
UK Barry K.B.Berkovitz MARTIN DUNITZ publications 2003
• Last’s Anatomy Regional and Applied. 12th edition 2011 Churchill
Livingstone publications
• Grays Anatomy for Students, 2nd edition 2012 Churchill Livingstone
publications