Infratemporal & pterygopalatine fossae

Report
Kaan Yücel M.D., Ph.D.
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.
Infratemporal Fossa
 Irregularly shaped space deep and inferior to the zygomatic arch,
deep to the ramus of the mandible and posterior to the maxilla.
 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,
The infratemporal fossa is inferior to the zygomatic arch.
The boundaries of the infratemporal fossa
Laterally: ramus of the mandible
Medially: lateral pterygoid plate
Anteriorly: posterior aspect of the maxilla
Posteriorly: tympanic plate ,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)
2)
3)
4)
5)
6)
Inferior part of the temporalis muscle
Lateral and medial pterygoid muscles
Maxillary artery
Pterygoid venous plexus
Mandibular, inferior alveolar, lingual, buccal, chorda tympani nerves
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)
2)
3)
4)
Deep temporal aa. (to the temporal muscle)
Pterygoid aa. (to the pterygoid muscles)
Masseteric artery (to the masseter muscle)
Buccal artery (to the buccinator muscle)
o
o
o
o
o
o
o
o
o
o
o
deep auricular (da)
anterior tympanic (at)
middle meningeal (mm)
accessory middle meningeal (amm)
inferior alveolar (ia)
buccal (b)
deep temporal (dt)
posterior superior alveolar (psa)
descending palatine (dp)
infraorbital (io)
sphenopalatine (sp)
Pterygoid venous plexus
 Located partly between the temporalis and the pterygoid muscles.
 The venous equivalent of most of the maxillary
 Actually a network of veins formed by the veins following the
branches of maxillary artery.
Mandibular nerve
 Arises from the trigeminal ganglion in the middle cranial fossa.
 Immediately receives the motor root of the trigeminal nerve
 Leaves the cranium through the foramen ovale into the infratemporal
fossa.
Mandibular nerve
 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.
Auriculotemporal nerve
 Supplies sensory fibers to the auricle and temporal region.
 Also sends articular (sensory) fibers to the TMJ.
 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.
The terminal branch of the inferior alveolar nerve is the mental nerve
which passes through the mental foramen.
Lingual nerve
sensory to the anterior two thirds of the tongue, the floor of the
mouth, and the lingual gingivae.
o deep temporal (dt)
o auriculotemporal (at)
o inferior alveolar (ia)
o nerve to the mylohyoid (nmh)
o lingual (l)
o buccal (b)
o branches to lateral pterygoid (not
labeled)
o Not shown: meningeal branch
o nerve to masseter
Chorda tympani nerve
 A branch of CN VII carrying taste fibers from the anterior two thirds
of the tongue.
 Joins the lingual nerve in the infratemporal fossa.
 Also carries secretomotor fibers for the submandibular & sublingual
salivary glands.
Otic ganglion (parasympathetic)
 Located in the infratemporal fossa, just inferior to the foramen
ovale. Presynaptic parasympathetic fibers, derived mainly from
the glossopharyngeal nerve (via the lesser petrosal nerve), synapse
in the otic ganglion.
 Postsynaptic parasympathetic fibers, secretory to the parotid
gland, pass from the otic ganglion to this gland through the
auriculotemporal nerve.
auriculotemporal nerve
glossopharyngeal nerve
(via the lesser petrosal nerve)
Pterygopalatine Fossa
 A small space behind and below the orbital cavity.
 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
7 foramina and fissures provide apertures through which structures
enter and leave the pterygopalatine fossa:






foramen rotundum & pterygoid canal middle cranial fossa
palatovaginal canal nasopharynx
palatine canal leads oral cavity (hard palate)
sphenopalatine foramen nasal cavity
pterygomaxillary fissure infratemporal fossa
inferior orbital fissure orbit
Gateways
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.
+
parasympathetic fibers from the facial nerve [VII]
Sympathetic fibers from the T1 spinal cord level joinining the 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:
• anterior wall is formed by the posterior surface of the maxilla;
• medial wall is formed by the lateral surface of the palatine bone;
• 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:
• maxillary nerve [V2] through foramen rotundum middle cranial
fossa
• greater petrosal nerve from the facial nerve [VII] + sympathetic fibers
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)
2)
3)
4)
Third part (pterygopalatine part) of the maxillary artery
Maxillary nerve
Nerve of the pterygoid canal (Vidian’s nerve)
Pterygopalatine ganglion
Lacrimal Gland
 Consists of a large orbital part and a small palpebral part.
 Situated above the eyeball in the anterior and upper part of the orbit
posterior to the orbital septum.
 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 via the
nervus intermedius and its great petrosal branch.
 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)
 Purely sensory
 Originates from the trigeminal
ganglion in the cranial cavity
 Exits the middle cranial fossa
 Enters the pterygopalatine
fossa (foramen rotundum)
 Exits as the infra-orbital nerve
(inferior orbital fissure)
 Gives sensory fibers to the skin
of the face and the side of the
nose.
Maxillary Nerve (V2)
Branches
Within the fossa, the maxillary nerve is attached to the pterygopalatine
ganglion by two ganglionic branches.
 Sensory fibers from the nose, the palate, and the pharynx.
 Postganglionic parasympathetic fibers to the lacrimal gland.
More anteriorly posterior superior alveolar nerves are given off.
Pass through the pterygopalatine maxillary fissure into the
infratemporal fossa.
Here they divide into numerous small branches
• Enter the maxilla through the posterior alveolar foramina
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.
divides into:
Zygomaticotemporal branch passing into temporal fossa to supply
skin of the temple
Zygomaticofacial nerve supplies skin over the prominence of cheek.
Pterygopalatine Ganglion
(Ganglion pterygopalatinum, Meckel's ganglion, Nasal ganglion, Sphenopalatine ganglion)
 Largest of the 4 parasympathetic ganglia in the head
 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.
Pterygopalatine Ganglion
 The postganglionic fibers, together with sympathetic fibers, join
fibers from the ganglionic branches of the maxillary nerve [V2].
 Postsynaptic fibers arising from the pterygopalatine 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, enter the orbit (inferior orbital fissure)
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, gives origin to posterior inferior nasal nerves,
which contribute to the innervation of the lateral nasal wall.
Greater petrosal nerve enters the pterygoid canal and becomes the
nerve of the pterygoid canal
• Pharyngeal branch, which supplies the roof of the nasopharynx
1.
2.
3.
4.
5.
6.
7.
infraorbital nerve
posterior superior alveolar nerve
pterygopalatine ganglion (parasympathetic)
greater palatine nerve
lesser palatine nerve cut
nasopalatine nerve
nerve of the pharyngeal canal
Maxillary Artery
 A major branch of the external carotid artery in the neck.
 Passes through the infratemporal fossa
 Enters the pterygopalatine fossa through the pterygomaxillary
fissure.
Branches of the third part of the maxillary artery
1)
2)
3)
4)
5)
6)
Posterior superior alveolar artery
Infra-orbital artery
Greater palatine artery
Pharyngeal artery
Sphenopalatine arteries
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.
Runs with the corresponding branches of the maxillary nerve to suppy
the upper posterior teeth and adjacent structures.
MAXILLARY ARTERY MNEMONICS
IDAMA 1ST PART
Inferior alveolar artery
Deep auricular
Anterior tympanic artery
Middle meningeal
Accessory meningeal aa.
Mehmet 2ND PART
Polat
Deniz
Buca
Masseteric artery
Pterygoid aa.
Deep temporal aa.
Buccal artery
PIG SAP 3RD PART
Posterior superior alveolar artery
Infra-orbital artery
Greater palatine artery
Sphenopalatine arteries
Artery of the pterygoid canal
Pharyngeal artery
Veins
The veins pass through the pterygomaxillary fissure to join the pterygoid
plexus of veins in the infratemporal fossa.

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