The pterygomaxillary fissure forms a critical communication corridor between the infratemporal fossa and the pterygopalatine fossa, allowing neurovascular structures to traverse deep facial spaces. Understanding this passage is essential for clinicians working in head, neck, and dental regions because it influences surgical planning, pain patterns, and spread of infection.
This article explains the relationship between the pterygomaxillary fissure and the pterygopalatine fossa, focusing on anatomy, surgical relevance, clinical correlations, and practical implications for diagnosis and intervention.
| Structure | Key Relations | Main Contents | Clinical Relevance |
|---|---|---|---|
| Pterygomaxillary Fissure | Between maxilla, sphenoid, and palatine bones | Maxillary artery, mandibular nerve branches, emissary veins | Potential pathway for spread of infection or tumor |
| Pterygopalatine Fossa | Medial to maxilla, posterior to nasal cavity | Maxillary nerve, pterygopalatine ganglion, branches of maxillary artery | Site for nerve blocks and origin of painful syndromes |
| Communication Role | Transmits neurovascular structures between fossa and infratemporal fossa | Maxillary artery, pterygoid venous plexus, mandibular nerve | Important in dental, sinus, and midface surgery |
| Surgical Landmarks | Pterygoid plates, tuberosity of maxilla, sphenopalatine foramen | Approach corridors for endoscopic and open procedures | Guides approach to skull base and deep facial spaces |
Anatomical definition of the pterygomaxillary fissure
The pterygomaxillary fissure is an oblique gap situated between the maxilla, the sphenoid bone, and the palatine bone. It serves as a lateral boundary of the pterygopalatine fossa, allowing neurovascular structures to move between the infratemporal fossa and the pterygopalatine fossa. Its positioning near the maxillary tuberosity and the pterygoid plates makes it a consistent landmark for surgical approaches to the midfacial skeleton.
Boundaries and connections
Superiorly, the fissure relates to the inferior surface of the greater wing of the sphenoid. Anteriorly, it borders the posterior surface of the maxilla, while medially it connects with the lateral wall of the nasal cavity. Posteriorly, it communicates with the infratemporal fossa, and inferiorly it interacts with the pterygoid venous plexus. These boundaries define a corridor that transmits critical vessels and nerves.
Structure and contents of the pterygopalatine fossa
The pterygopalatine fossa is a small cone-shaped space located medial to the ramus of the maxilla and posterior to the nasal cavity. It contains the maxillary nerve (V2) and its branches, the pterygopalatine ganglion, and several arterial branches. The relationship between the pterygomaxillary fissure and the pterygopalatine fossa is direct, as the fissure forms the main lateral entrance to this fossa.
Key neurovascular elements
Within the pterygopalatine fossa, the maxillary nerve gives off branches such as the zygomatic nerve, posterior superior alveolar nerve, and infraorbital nerve. The pterygopalatine ganglion, located in the fossa, provides parasympathetic fibers to the lacrimal gland and nasal mucosa. Vessels including the maxillary artery and its branches pass through the fissure into the fossa to supply deep facial structures.
Surgical relevance and approach considerations
Because the pterygomaxillary fissure provides a direct route between the infratemporal fossa and the pterygopalatine fossa, it is a key consideration in procedures involving the midface, skull base, and upper jaw. Surgeons must account for the neurovascular structures traversing this passage to avoid iatrogenic injury and to establish safe corridors for resection or reconstruction.
Clinical landmarks and techniques
During endoscopic endonasal approaches, identification of the sphenoid sinus and careful identification of the posterior maxillary wall help delineate the region of the fissure. In open approaches, the maxillary tuberosity and pterygoid plates serve as tactile guides. Preservation of major vessels and nerves near the fissure reduces the risk of postoperative pain, paresthesia, and hemorrhage.
Clinical correlations and imaging features
Imaging plays a vital role in appreciating the relationship between the pterygomaxillary fissure and the pterygopalatine fossa. On coronal CT scans, the fissure appears as a gap between the maxilla and the sphenoid, while MRI can delineate the neurovascular bundles passing through this region. Accurate interpretation helps in planning surgical approaches, local nerve blocks, and managing pathologies such as tumors, infections, and fractures.
Pathology involving the fissure and fossa
Lesions originating in or extending into the pterygomaxillary fissure and pterygopalatine fossa can cause facial pain, trismus, paresthesia, and nasal or oral symptoms. Conditions such as schwannomas, mucoceles, inflammatory masses, and metastatic deposits may distort anatomy and disrupt the function of nerves and vessels. Cross-sectional imaging and, when appropriate, biopsy guide targeted treatment strategies.
Key takeaways and recommendations
- Recognize the pterygomaxillary fissure as the main lateral gateway between the infratemporal fossa and the pterygopalatine fossa.
- Understand that the fossa houses the maxillary nerve, autonomic ganglia, and critical arterial branches.
- Use CT and MRI to evaluate the relation of the fissure and fossa in preoperative planning.
- Preserve neurovascular structures during surgical approaches to reduce pain and functional deficits.
- Consider this region in differential diagnosis for facial pain, dental symptoms, and midface masses.
FAQ
Reader questions
What symptoms might suggest pathology involving the pterygomaxillary fissure and pterygopalatine fossa?
Symptoms can include facial pain, numbness or tingling in the cheek or upper teeth, difficulty opening the mouth, nasal congestion or crusting, and tearing or dry eyes, depending on which nerves and structures are affected.
How is the pterygomaxillary fissure visualized on imaging?
On CT scans, the fissure appears as a low-attenuation gap between the maxilla and the sphenoid wing, and on MRI, neurovascular bundles show characteristic signal patterns that help identify this small but important space.
Why is the pterygopalatine fossa important in dental procedures?
The fossa is the target for posterior superior alveolar nerve blocks, and proximity to the pterygomaxillary fissure means that injections or surgical work in the maxilla must consider underlying neurovascular structures to avoid complications.
What role does the pterygomaxillary fissure play in skull base surgery?
The fissure serves as a corridor for endoscopic instruments and neurovascular structures, so surgeons use it as a landmark when approaching the midface, pterygopalatine fossa, and deeper skull base regions while minimizing damage to surrounding tissues.