Dr. Kaan Yücel
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Yeditepe Anatomy
INFRATEMPORAL & PTERYGOPALATINE FOSSAE
5.January.2011 Thursday
Structures inside the temporal fossa:
1) Temporal muscle
2) Temporal fascia (overlies the temporalis muscle)
3) Superficial temporal artery (br. of external carotid)
4) Superficial temporal vein (unites with the maxillary vein to form the retromandibular vein)
5) Auriculotemporal nerve (br. of mandibular nerve which is a br of the trigeminal nerve)
A knowledge of the anatomy of the infratemporal and pterygopalatine fossae and their contents is
essential for understanding the dental region. Many of the nerves and blood vessels supplying the structures
of the mouth run through or close to these fossae. In addition, the infratemporal fossa contains the
pterygoid muscles which play an important part in movements of the mandible. The posterior boundary of
the fossa is occupied by the styloid apparatus and carotid sheath and is closely related the last four cranial
nerves.
The infratemporal fossa is an irregularly shaped space deep and inferior to the zygomatic arch, deep
to the ramus of the mandible and posterior to the maxilla. It communicates with the temporal fossa through
the interval between (deep to) the zygomatic arch and (superficial to) the cranial bones.
Temporal fossa is superior to the zygomatic arch, and the infratemporal fossa is inferior to the zygomatic
arch. The boundaries of the infratemporal fossa are as follows:
• Laterally: the ramus of the mandible
• Medially: the lateral pterygoid plate
• Anteriorly: the posterior aspect of the maxilla
• Posteriorly: the tympanic plate and the mastoid and styloid processes of the temporal bone
• Superiorly: the inferior (infratemporal) surface of the greater wing of the sphenoid
• Inferiorly: where the medial pterygoid muscle attaches to the mandible near its angle
The infratemporal fossa contains the:
1) Inferior part of the temporalis muscle
2) Lateral and medial pterygoid muscles
3) Maxillary artery
4) Pterygoid venous plexus
5) Mandibular, inferior alveolar, lingual, buccal, and chorda tympani nerves
6) Otic ganglion
Neurovasculature of the infratemporal fossa
The maxillary artery is the larger of the two terminal branches of the external carotid artery. It
arises posterior to the neck of the mandible and is divided into three parts based on its relation to the lateral
pterygoid muscle.
1st (mandibular) part: Deep to the condyle of mandible
2nd (pterygoid) part: Neighbourhood of lateral pterygoid muscle
3rd (pterygopalatine) part: Inside the infratemporal fossa (extends into the pterygopalatine fossa)
Branches of the 1st part:
1. Deep auricular (to external acoustic meatus)
2. Anterior tympanic artery (to the tympanic membrane)
3. Middle meningeal (to dura mater and calvaria)
4. Accessory meningeal aa. (to the cranial cavity)
5. Inferior alveolar artery (to the mandibular gingiva and teeth)
Branches of the 2nd part:
1. Deep temporal aa. (to the temporal muscle)
2. Pterygoid aa. (to the pterygoid muscles)
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3. Masseteric artery (to the masseter muscle)
4. Buccal artery (to the buccinator muscle)
The pterygoid venous plexus is located partly between the temporalis and the pterygoid muscles. It
is the venous equivalent of most of the maxillary artery—that is, most of the veins that accompany the
branches of the maxillary artery drain into this plexus. It is actually a network of veins formed by the veins
following the branches of maxillary artery. The plexus anastomoses with the facial vein via the deep facial
vein and with the cavernous sinus via emissary veins. The maxillary vein unites with the superficial temporal
vein to form the retromandibular vein.
The mandibular nerve arises from the trigeminal ganglion in the middle cranial fossa. It
immediately receives the motor root of the trigeminal nerve and leaves the cranium through the foramen
ovale into the infratemporal fossa. The mandibular nerve contains GSA and SVE fibers
Branches of CN V3 supply the four muscles of mastication but not the buccinator, which is supplied by the
facial nerve. Branches within the infratemporal fossa is divided into three groups:
1) Branches arising from the trunk
– Spinous nerve
– Medial pterygoid nerve
2) Anterior branches
– Buccal nerve
– Masseteric nerve
– Deep temporal nerves
– Lateral pterygoid nerve
3) Posterior branches
– Auriculotemporal nerve
– Lingual nerve
– Inferior alveolar nerve
The spinous nerve passes through the spinous foramen and enters the cranium. It is a sensory nerve
innervating the dura mater.
The medial pterygoid nerve innervates the medial pterygoid muscle, tensor veli palatini muscle and the
tensor tympani muscle. Buccal nerve, masseteric nerve, deep temporal nerves, lateral pterygoid nerve
innervate the muscles with the same name except the buccal nerve. Buccal nerve is sensory and innervates
the inner surface of the cheek.
The auriculotemporal nerve supplies sensory fibers to the auricle and temporal region. The
auriculotemporal nerve also sends articular (sensory) fibers to the TMJ. It conveys postsynaptic
parasympathetic secretomotor fibers from the otic ganglion to the parotid gland.
The inferior alveolar nerve enters the mandibular foramen and passes through the mandibular canal,
forming the inferior dental plexus, which sends branches to all mandibular teeth on its side. Before entering
the canal, gives two motor branches that supply the anterior belly of digastric and mylohyoid muscle. The
terminal branch of the inferior alveolar nerve is the mental nerve which passes through the mental foramen.
The lingual nerve is sensory to the anterior two thirds of the tongue, the floor of the mouth, and the lingual
gingivae.
The chorda tympani nerve, a branch of CN VII carrying taste fibers from the anterior two thirds of
the tongue. The chorda tympani joins the lingual nerve in the infratemporal fossa. The chorda tympani also
carries secretomotor fibers for the submandibular and sublingual salivary glands.
The otic ganglion (parasympathetic) is located in the infratemporal fossa, just inferior to the foramen
ovale. Presynaptic parasympathetic fibers, are located in the glossopharyngeal nerve [IX] as it exits the
jugular foramen at the base of the skull. The tympanic nerve, a branch of the CN IX, forms a plexus called
tympanic plexus. The lesser petrosal nerve is a branch of this plexus. The presynaptic parasympatic nerves
are carried by the lesser petrosal nerve to the otic ganglion. Postsynaptic parasympathetic fibers, which
are secretory to the parotid gland, pass from the otic ganglion to this gland through the auriculotemporal
nerve.
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The pterygopalatine fossa is a small space behind and below the orbital cavity. The pterygopalatine fossa is
an inverted 'tear-drop' shaped space between bones on the lateral side of the skull immediately posterior to
the maxilla. Although small in size, the pterygopalatine fossa communicates via fissures and foramina in its
walls with:
1) the middle cranial fossa
2) infratemporal fossa
3) floor of the orbit
4) lateral wall of the nasal cavity
5) oropharynx
6) roof of the oral cavity.
Gateways
Seven foramina and fissures provide apertures through which structures enter and leave the pterygopalatine
fossa:
 the foramen rotundum and pterygoid canal communicate with the middle cranial fossa
 a small palatovaginal canal leads to the nasopharynx;
 the palatine canal leads to the roof of the oral cavity (hard palate)
 the sphenopalatine foramen opens in the nasal cavity
 the pterygopalatine fossa is continuous with the infratemporal fossa via a large gap (the
pterygomaxillary fissure) between the posterior surface of the maxilla and pterygoid process of the
sphenoid bone;
 the fossa opens into the floor of the orbit via the inferior orbital fissure
Because of its strategic location, the pterygopalatine fossa is a major site of distribution for the maxillary
nerve [V2] and for the terminal part of the maxillary artery. In addition, parasympathetic fibers from the
facial nerve [VII] and sympathetic fibers originating from the T1 spinal cord level join branches of the
maxillary nerve [V2] in the pterygopalatine fossa. All the upper teeth receive their innervation and blood
supply from the maxillary nerve [V2] and the terminal part of the maxillary artery, respectively, that pass
through the pterygopalatine fossa.
Skeletal framework
The walls of the pterygopalatine fossa are formed by parts of the palatine, maxilla, and sphenoid bones:
 the anterior wall is formed by the posterior surface of the maxilla;
 the medial wall is formed by the lateral surface of the palatine bone;
 the posterior wall and roof are formed by parts of the sphenoid bone.
The part of the sphenoid bone that contributes to the formation of the pterygopalatine fossa is the
anterosuperior surface of the pterygoid process. Opening onto this surface are two large foramina:
 the maxillary nerve [V2] passes through the foramen rotundum which communicates posteriorly with
the middle cranial fossa;
 the greater petrosal nerve from the facial nerve [VII] and sympathetic fibers from the internal carotid
plexus join to form the nerve of the pterygoid canal that passes into the pterygopalatine fossa through the
anterior opening of the pterygoid canal.
The pterygoid canal is a bony canal opening onto the posterior surface of the pterygoid process. The
pterygoid canal opens into the middle cranial fossa just anteroinferior to the internal carotid artery as the
vessel enters the cranial cavity through the carotid canal.
The contents of the pterygopalatine fossa:
1) Third part (pterygopalatine part) of the maxillary artery
2) Maxillary nerve
3) Nerve of the pterygoid canal
4) Pterygopalatine ganglion
As the pterygopalatine fossa contains the maxillary nerve, the pterygopalatine ganglion and the third part of
the maxillary artery, it is intimately concerned with the nerve and blood supply of the upper jaw.
The maxillary nerve [V2] and terminal part of the maxillary artery enter and branch within the
pterygopalatine fossa. In addition, the nerve of the pterygoid canal enters the fossa. The preganglionic
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parasympathetic fibers synapse in the pterygopalatine ganglion and both the sympathetic and
postganglionic parasympathetic fibers pass with branches of the maxillary nerve [V2] out of the fossa and
into adjacent regions. In addition to nerves and arteries, veins and lymphatics also pass through the
pterygopalatine fossa.
Lacrimal Gland
The lacrimal gland consists of a large orbital part and a small palpebral part. It is situated above the eyeball
in the anterior and upper part of the orbit posterior to the orbital septum. The gland opens into the lateral part
of the superior fornix of the conjunctiva.
Innervation of the lacrimal gland
The parasympathetic secretomotor nerve supply is derived from the lacrimal nucleus of the facial nerve.
The preganglionic fibers reach the pterygopalatine ganglion (sphenopalatine ganglion) via the nervus
intermedius and its great(er) petrosal branch (and via the nerve of the pterygoid canal; greater petrosal nerve
enters the pterygoid canal and becomes the nerve of the pterygoid canal). The postganglionic
parasympathetic and sympathetic fibers leave the zygomaticotemoral branch of the zygomatic nerve and
form a special autonomic nerve, which joins the lacrimal nerve. The lacrimal nerve is a major general
sensory branch of the ophthalmic nerve [V1]. The postganglionic parasympathetic and sympathetic fibers
pass with the lacrimal nerve to the lacrimal gland.
Maxillary Nerve (V2)
The maxillary nerve [V2] is purely sensory. It originates from the trigeminal ganglion in the cranial
cavity, exits the middle cranial fossa, and enters the pterygopalatine fossa through the foramen rotundum.
It exits as the infra-orbital nerve through the inferior orbital fissure.
Branches
V2 gives sensory fibers to the skin of the face and the side of the nose. Within the fossa, the maxillary
nerve is attached to the pterygopalatine ganglion by two ganglionic branches. Ganglionic branches, contain
sensory fibers that have passed through the ganglion from the nose, the palate, and the pharynx. They also
contain postganglionic parasympathetic fibers that are going to the lacrimal gland.
More anteriorly the posterior superior alveolar nerves are given off. Usually two or three in number,
these pass downwards and laterally through the pterygopalatine maxillary fissure into the infratemporal
fossa. Here they run on the posterior surface of the maxilla and divide into numerous small branches which
enter the maxilla through the posterior alveolar foramina and supply the upper molar teeth, the mucous
membrane on the buccal surface of the associated alveolar process and the lining of the maxillary sinus.
Anesthesia of the upper molar teeth and associated buccal mucosa can be achieved by a posterior superior
alveolar block.
As the maxillary nerve is about to enter the inferior orbital fissure it gives rise to the zygomatic nerve.
This runs forward through the fissure and along the lateral wall of the orbit where it divides into
zygomaticotemporal and zygomaticofacial branches. These nerves leave the orbit through canals in the
zygomatic bone, the zygomaticotemporal branch passing into the temporal fossa to supply the skin of the
temple, and the zygomaticofacial nerve emerging more anteriorly to supply the skin over the prominence of
the cheek. The zygomatic nerve also contains postganglionic parasympathetic fibres from the
pterygopalatine ganglion. Within the orbit these pass in a communicating branch from the
zygomaticotemporal nerve to the lacrimal nerve and reach the lacrimal gland.
Pterygopalatine Ganglion
The pterygopalatine ganglion is the largest of the four parasympathetic ganglia in the head. It is
located deep within the pterygopalatine fossa close to the sphenopalatine foramen. It is a relay station for
parasympathetic secremotor fibres derived from the facial nerve and destine for the lacrimal gland and the
glands of the mucous membranes of the nose, nasopharnyx, paranasal sinuses, palate, and upper lip. The
maxillary branches pass through the ganglion without interruption.
The pterygopalatine ganglion is formed by the cell bodies of the postganglionic neurons associated
with preganglionic parasympathetic fibers of the facial nerve [VII] carried by the greater petrosal nerve and
the nerve of the pterygoid canal. The first neuron of these preganglionic parasympathetic fibres is superior
salivatory nucleus. The postganglionic fibers, together with sympathetic fibers, join fibers from the
ganglionic branches of the maxillary nerve [V2]. Postsynaptic fibers arising from the pterygopalatine
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ganglion supply the lacrimal gland as well as nasal glands and minor salivary glands within the oral cavity.
The postsynaptic fibers innervating the lacrimal gland pass to the lacrimal nerve to reach the lacrimal gland.
Branches

Orbital branches, which enter the orbit through the inferior orbital fissure. They contribute to the supply
of the orbital wall and of the sphenoidal and ethmoidal sinuses.
 Greater and lesser palatine nerves, supply the palate, the tonsil, and the nasal cavity. The greater
palatine nerve originates from the geniculate ganglion of the facial nerve [VII] in the temporal bone. In the
palatine canal, the greater palatine nerve gives origin to posterior inferior nasal nerves, which contribute to
the innervation of the lateral nasal wall. The greater palatine nerve supplies the mucous membrane and
associated glands, of the palate as forwards as the lateral incisor region. Wihin the greater palatine canal the
nerve gives rise to nasal branches which pierce the perpendicular plate of the posteroinferior quadrant of the
lateral wall of the nose.
 The lesser palatine nerves also descend in the greater palatine canal but emerge on to the oral surface of
the bony palate through the lesser palatine foramina. They supply the mucous membrane of the soft palate
and of an area around the palatine tonsil. The taste fibres from this region are believed to pass back to the
pterygopalatine ganglion (through which they pass without interruption) and then travel in the nerve of the
pterygoid canal and in the greater petrosal nerve to the facial nerve.
 The pharyngeal nerve (branches) leaves the pterygopalatine ganglion and passes through the
palatovaginal canal to be distributed to the mucous membrane of the nasopharynx.
Maxillary Artery
The maxillary artery is a major branch of the external carotid artery in the neck. It passes through the
infratemporal fossa, and then enters the pterygopalatine fossa through the pterygomaxillary fissure.
It passes across the fossa and then through the inferior orbital fissure to enter the orbit, where it is known as
the infraorbital artery.Branches of the third part of the maxillary artery (i.e., that part of the vessel within the
pterygopalatine fossa) include the posterior superior alveolar, infra-orbital, greater palatine,
pharyngeal, and sphenopalatine arteries, and the artery of the pterygoid canal. Collectively, these
branches supply much of the nasal cavity, the roof of the oral cavity, and all upper teeth. In addition, they
contribute to the blood supply of the sinuses, oropharynx, and floor of the orbit.
The maxillary artery gives off the posterior superior alveolar branch as it enters the pterygopalatine
fossa. The posterior superior alveolar artery runs with the corresponding branches of the maxillary nerve to
suppy the upper posterior teeth and adjacent structures. The posterior superior alveolar artery may give rise
to a sizeable buccogingival branch which runs forwards on the posterior and then anterior surface of the
maxilla, below the zygomatic process, to reach the infraorbital region where it may anastomose with the
infraorbital artery. It is usually accompanied by a vein which is a tributary of the facial vein. The artery and
vein lie immediately adjacent to periosteum, and may be at risk of being punctured in injections to obtain
anesthesia of the maxillary teeth.
Veins that drain areas supplied by branches of the terminal part of the maxillary artery travel with these
branches back into the pterygopalatine fossa. The veins pass through the pterygomaxillary fissure to join the
pterygoid plexus of veins in the infratemporal fossa.
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