What are the boundaries of the pterygopalatine fossa?

Boundaries of the Pterygopalatine Fossa

The pterygopalatine fossa is a small, deeply located anatomic space with specific boundaries: anteriorly by the posterior wall of the maxillary sinus, posteriorly by the pterygoid process of the sphenoid bone, medially by the perpendicular plate of the palatine bone, laterally by the pterygomaxillary fissure, superiorly by the greater wing of the sphenoid containing the foramen rotundum, and inferiorly by the pyramidal process of the palatine bone.

Anatomical Structure and Compartments

The pterygopalatine fossa can be divided into two distinct compartments:

• Upper (orbital) floor: Contains the pterygopalatine ganglion in its medial compartment 1
• Lower (pterygomaxillary) floor: Contains critical neurovascular structures 1

Communications

The pterygopalatine fossa communicates with multiple adjacent spaces through various foramina and canals:

1. Middle cranial fossa: Via foramen rotundum
2. Orbit: Via inferior orbital fissure
3. Nasal cavity: Via sphenopalatine foramen
4. Oral cavity: Via greater and lesser palatine foramina
5. Pharynx: Via palatinovaginal canal
6. Foramen lacerum: Via pterygoid (vidian) canal
7. Infratemporal fossa: Via pterygomaxillary fissure 2

Important Neurovascular Contents

The pterygopalatine fossa contains critical structures arranged in two layers:

1. Nervous layer:

   • Maxillary nerve (V2)
   • Pterygopalatine ganglion
   • Nerve of pterygoid canal (vidian nerve)

2. Vascular layer:

   • Pterygopalatine segment of maxillary artery and accompanying veins 3

Clinical Significance

Understanding the boundaries and contents of the pterygopalatine fossa is crucial for:

• Surgical approaches: The posterior wall of the maxillary sinus serves as an important landmark, with the intersection of the upper wall, inner wall, and back wall being a critical reference point 3

• Disease spread: Infectious diseases and malignancies can spread through the pterygopalatine fossa to contiguous areas due to the low resistance offered by its numerous communications 4

• Tumor assessment: Involvement of the pterygopalatine fossa, particularly when associated with severe trismus or cranial neuropathy, is associated with poor prognosis in head and neck cancers 5

Imaging Considerations

• CT imaging: High-resolution CT is the preferred modality for evaluating the pterygopalatine fossa and its communications 2

• 3D volume rendering: Provides accurate identification of variable pneumatization patterns that affect the boundaries of the pterygopalatine fossa 1

• Morphometric variations: The central diameters of the foramen rotundum and vidian canal are significantly smaller than their anterior and posterior transverse diameters, which is important for surgical planning 6

Understanding these anatomical relationships is essential for surgical approaches to this region and for assessing the extent of disease in cases of head and neck malignancies.