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Explain pterygomaxilary fissure with relationship to nasal caviry and sphenopalatine fossa

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I now have comprehensive information from the textbooks and excellent diagrams. Let me compile the full answer.

Pterygomaxillary Fissure: Anatomy, Relationships, and Clinical Relevance

What Is the Pterygomaxillary Fissure?

The pterygomaxillary fissure is a vertical gap (fissure) formed between two bony structures:
  • Anteriorly: the posterior (infratemporal) surface of the maxilla
  • Posteriorly: the anterior surface of the pterygoid process of the sphenoid bone
It is the lateral opening of the pterygopalatine fossa (PPF) and serves as the primary channel of communication between the PPF and the infratemporal fossa.

The Pterygopalatine (Pterygomaxillary) Fossa

The pterygopalatine fossa is an inverted teardrop- (or cone-) shaped space located on the lateral skull, immediately posterior to the maxilla near the orbital apex. Despite its small size, it is one of the most anatomically strategic spaces in the head.

Bony Walls

WallBone
AnteriorPosterior surface of the maxilla
Posterior & roofPterygoid process + greater wing of sphenoid
MedialPerpendicular plate of the palatine bone (abuts lateral nasal wall)
LateralOpen - communicates via the pterygomaxillary fissure
Inferior (apex)Narrows into the greater palatine canal
SuperiorOpens into the inferior orbital fissure
(Gray's Anatomy for Students, p. 1132-1134; K.J. Lee's Essential Otolaryngology, p. 700)

The Pterygomaxillary Fissure in Detail

Gateways of the Pterygopalatine Fossa - Gray's Anatomy
Gateways of the Pterygopalatine Fossa. The pterygomaxillary fissure (lower left) connects the PPF to the infratemporal fossa laterally.
Pterygopalatine Fossa - anterolateral and lateral views
Pterygopalatine fossa viewed anterolaterally (left) and laterally (right), showing its bony foramina and canals.

Key Structural Relationships

The fissure itself is positioned inferiorly on the lateral aspect of the PPF. In contrast, the inferior orbital fissure occupies the superior lateral aspect. Together, these two fissures form the deficient lateral wall of the PPF:
  • Inferior orbital fissure (superiorly) → communicates with the floor of the orbit
  • Pterygomaxillary fissure (inferiorly) → communicates with the infratemporal fossa
(K.J. Lee's Essential Otolaryngology, p. 632)

Structures Passing Through the Pterygomaxillary Fissure

Into the PPF (from the infratemporal fossa):
  • The maxillary artery (third/pterygomaxillary portion) ascends obliquely through the infratemporal fossa and enters the PPF via this fissure - it may travel either medial or lateral to the lower head of the lateral pterygoid muscle before entering
  • The pterygoid venous plexus drains into veins that coalesce in the PPF and then pass laterally back through the fissure to join the pterygoid plexus in the infratemporal fossa
  • The posterior superior alveolar nerve (from V2 in the PPF) exits via this fissure and descends on the posterolateral surface of the maxilla
(Gray's Anatomy for Students, p. 1133-1134)

All Seven Gateways of the Pterygopalatine Fossa

OpeningDirectionCommunicates with
Pterygomaxillary fissureLateralInfratemporal fossa
Inferior orbital fissureSuperolateralFloor of orbit
Sphenopalatine foramenMedialLateral wall of nasal cavity
Foramen rotundumPosteriorMiddle cranial fossa (V2 enters)
Pterygoid (Vidian) canalPosteriorMiddle cranial fossa (Vidian nerve)
Palatovaginal canalPosterior/inferiorNasopharynx
Greater palatine canalInferiorRoof of oral cavity (hard palate)

Relationship to the Nasal Cavity

The PPF connects to the nasal cavity medially via the sphenopalatine foramen. This is not a direct role of the pterygomaxillary fissure itself, but the fissure and foramen are the two poles of the PPF:
  • The pterygomaxillary fissure = lateral communication (to infratemporal fossa)
  • The sphenopalatine foramen = medial communication (to nasal cavity)

The Sphenopalatine Foramen

Formed by the sphenopalatine notch of the palatine bone and the body of the sphenoid, this foramen lies in the posterolateral wall of the superior nasal meatus, just superior to the attachment of the posterior end of the middle nasal concha.
Structures transmitted medially through it into the nasal cavity:
  1. Sphenopalatine artery (terminal branch of the maxillary artery) - the most important arterial supply to the nasal cavity; divides into posterior lateral nasal and posterior septal branches
  2. Nasopalatine nerve (branch of V2)
  3. Superior nasal branches of the maxillary nerve (V2)
(Gray's Anatomy for Students, p. 1134; Scott-Brown's Otorhinolaryngology, Vol. 2, p. 1249)
So the pathway from the infratemporal fossa to the nasal cavity runs:
Infratemporal fossa → pterygomaxillary fissure → pterygopalatine fossa → sphenopalatine foramen → nasal cavity

Contents of the Pterygopalatine Fossa

Three major structures reside in the PPF:
  1. Maxillary nerve (V2) - enters via foramen rotundum; the most important sensory nerve for the upper teeth, palate, nasal cavity, and cheek
  2. Pterygopalatine (sphenopalatine) ganglion - a parasympathetic ganglion; preganglionic fibers from CN VII (via greater petrosal nerve → Vidian nerve) synapse here; postganglionic fibers hitch a ride on V2 branches to reach the lacrimal gland, nasal mucosa, and palate
  3. Terminal part of the maxillary artery (third portion) - enters via the pterygomaxillary fissure and branches into the sphenopalatine, infraorbital, descending palatine, and posterior superior alveolar arteries
Within the lateral wall, vascular structures are anterior to neural structures and encountered first surgically.
(Scott-Brown's Vol. 2, p. 1249; K.J. Lee's, p. 700)

Masticator Space Connection

The masticator space communicates with the PPF via the pterygomaxillary fissure. The muscles of mastication and the mandibular division of the trigeminal nerve (V3) are contained within the masticator space, which connects inferolaterally through this fissure. (Scott-Brown's, Vol. 3)

Clinical Significance

  1. Juvenile nasopharyngeal angiofibroma (JNA): These tumors classically arise near the sphenopalatine foramen and extend laterally through the pterygomaxillary fissure into the infratemporal fossa - widening of this fissure on imaging (Holman-Miller sign/antral sign) is a classic radiological finding.
  2. Sphenopalatine ganglion (SPG) block: The lateral approach to the SPG targets the fossa via the pterygomaxillary fissure with a needle passed through the coronoid notch of the mandible - used for cluster headaches, trigeminal neuralgia, and nasal procedures.
  3. Endoscopic skull base surgery: Medial access to the PPF is via the sphenopalatine foramen (medial wall), while lateral access requires going through the pterygomaxillary fissure - the approach chosen depends on tumor location and extension.
  4. Spread of infection/tumor: The PPF acts as a crossroads - tumors of the nasal cavity, maxillary sinus, nasopharynx, or infratemporal fossa can all reach the middle cranial fossa by spreading through the PPF along nerve sheaths (perineural spread, especially along V2).
Sources: Gray's Anatomy for Students (pp. 1132-1134); K.J. Lee's Essential Otolaryngology (pp. 632, 700); Scott-Brown's Otorhinolaryngology Head & Neck Surgery Vol. 2 (p. 1249); Scott-Brown's Vol. 1 (p. 1313)

I have a doubt... The macilary artery first enters the nose via foramen rotundum and then goes into the sphenopalatine foramen right

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Good - now the full picture is clear. Here's the correction:

Correcting the Misconception

The foramen rotundum carries V2 (maxillary nerve), NOT the maxillary artery.
These two "maxillary" structures travel completely different routes:
Maxillary Nerve (V2)Maxillary Artery
OriginTrigeminal ganglion (middle cranial fossa)External carotid artery (neck)
Route into PPFVia foramen rotundum (posterior wall)Via pterygomaxillary fissure (lateral wall)
Direction of travelCranial fossa → PPF (going forward/down)Infratemporal fossa → PPF (going medially)

The Correct Path of the Maxillary Artery

Maxillary Artery in the Pterygopalatine Fossa - Gray's Anatomy
The complete journey is:
External carotid artery (neck, near neck of mandible) → passes forward through the infratemporal fossa (this is the 2nd part) → enters the pterygopalatine fossa via the pterygomaxillary fissure (this is the 3rd/pterygomaxillary part) → branches out inside the PPF → its terminal branch = sphenopalatine artery exits medially through the sphenopalatine foramen → enters the nasal cavity
So the route into the nose is: pterygomaxillary fissure → PPF → sphenopalatine foramen → nasal cavity. The foramen rotundum is never involved.

Branches of the Maxillary Artery from the PPF

Once inside the PPF, the maxillary artery gives off 5-6 branches, each leaving through a different gateway:
BranchExits viaSupplies
Posterior superior alveolar a.Pterygomaxillary fissure (back out)Molar/premolar teeth, maxillary sinus
Infra-orbital a.Inferior orbital fissureFace, anterior teeth
Greater palatine a.Palatine canal (inferiorly)Hard palate, anterior nasal septum
Pharyngeal a.Palatovaginal canalRoof of nasal cavity, sphenoid sinus
Sphenopalatine a. (terminal)Sphenopalatine foramenLateral nasal wall, nasal septum
Artery of pterygoid canalPterygoid canal (posteriorly)Nasopharynx mucosa
(Gray's Anatomy for Students, pp. 1138-1139)
The sphenopalatine artery is the most important blood supply to the nasal cavity and is the vessel ligated or embolised in refractory epistaxis. It is the terminal branch of the maxillary artery - the artery "ends" here after giving off all its other branches inside the PPF.

Can u generate an image explaining the pathwy from infratempiral fossa to nasal cavity

Generating Image

Medical anatomy diagram showing the pathway of the maxillary artery from the infratemporal fossa to the nasal cavity. Clean educational diagram with labeled arrows showing the step-by-step route: 1) External carotid artery branching into maxillary artery near neck of mandible, 2) Maxillary artery traveling through the infratemporal fossa (2nd part), 3) Entering the pterygopalatine fossa via the pterygomaxillary fissure (gap between posterior maxilla and pterygoid process of sphenoid), 4) Branching inside the pterygopalatine fossa into posterior superior alveolar artery, infraorbital artery, greater palatine artery, pharyngeal artery, and sphenopalatine artery, 5) Terminal sphenopalatine artery exiting medially through the sphenopalatine foramen into the nasal cavity where it divides into posterior lateral nasal branches and posterior septal branches. Also show the maxillary nerve V2 entering the pterygopalatine fossa via foramen rotundum separately, clearly labeled to distinguish it from the artery. Color coded: artery in red, nerve in yellow. Side cross-section view of skull showing bones: maxilla, sphenoid pterygoid process, palatine bone. Title: "Pathway: Infratemporal Fossa to Nasal Cavity via Pterygopalatine Fossa"

Pathway from Infratemporal Fossa to Nasal Cavity
Here is a summary of what the diagram shows:
Maxillary Artery pathway (red):
  1. Branches from the external carotid artery near the neck of the mandible
  2. Travels medially through the infratemporal fossa (2nd part)
  3. Enters the pterygopalatine fossa via the pterygomaxillary fissure (the lateral gap between the maxilla and pterygoid process)
  4. Branches out inside the PPF - posterior superior alveolar, infraorbital, greater palatine, pharyngeal, artery of pterygoid canal
  5. Its terminal branch (sphenopalatine artery) exits medially through the sphenopalatine foramen into the nasal cavity, dividing into posterior lateral nasal and posterior septal branches
Maxillary nerve V2 (yellow) - for comparison:
  • Comes from the middle cranial fossa
  • Enters the PPF via foramen rotundum (posterior wall) - completely separate from the artery's route
The key takeaway: the artery enters the PPF laterally (pterygomaxillary fissure), while the nerve enters it posteriorly (foramen rotundum). Both then distribute branches that exit through the same onward channels.
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