Areas - Pterygopalatine Fossa

Question 1

Where is the pterygopalatine fossa located?

Answer 1

It is located between the maxilla, sphenoid and palatine bones.

Question 2

What are the borders of the pterygopalatine fossa?

Answer 2

Anterior - posterior wall of the maxillary sinus

Posterior - pterygoid process of the sphenoid bone

Inferior - Palatine bone and palatine canals

Superior - inferior orbital fissure

Medial - Perpendicular plate of the palatine bone

Lateral - pterygomaxillary fissure

Question 3

What are the contents of the pterygopalatine fossa?

Answer 3

1) Maxillary nerve
2) Pterygopalatine ganglion
3) Maxillary artery

Question 4

Maxillary nerve

branches?

Answer 4

2nd branch of the trigeminal nerve.

Middle cranial fossa to the pterygopalatine fossa via foramen rotundum.

Main trunk of the maxillary nerve leaves the fossa via the inferior orbital fissure. It then enters the infraorbital canal and then the infraorbital foramen to contribute to the sensation of the face.

Branches - infraorbital, zygomatic, nasopalatine, superior alveolar, pharyngeal, and the greater and lesser palatine nerves.

Question 5

Pterygopalatine ganglion

Answer 5

Sits deep within the pterygopalatine fossa, near the sphenopalatine foramen.

Predominanatly innervated by the greater petrosal nerve.

Post synaptic fibres - secretomotor in function - parasympathetic supply to the lacrimal gland, mucosal glands of the oral cavity, nose and pharynx.

Question 6

Maxillary artery

Answer 6

Terminal branch of the external carotid artery.

Branches of the maxillary:

i) Sphenopalatine artery - nasal cavity
ii) Descending palatine artery - branches into greater and lesser palatine arteries (hard and soft palate).
iii) Infraorbital artery - lacrimal gland, some muscles of the eye
iv) Posterior superior alveolar artery - teeth and gingiva

Question 7

Foramina of the pterygopalatine fossa

Answer 7

1) Pterygomaxillary fissure - to the infratemporal fossa

- Posterior superior alveolar artery

- Terminal end of maxillary artery

2) Foramen rotundum - from the middle cranial fossa

- Maxillary nerve

3) Pterygoid and pharyngeal canals

Along with the foramen rotundum, these canals are located on the posterior wall of pterygopalatine fossa.

• Pterygoid canal - middle cranial fossa through medial pterygoid plate - nerve, vein, and artery of pterygoid canal.
• pharyngeal canal - communicates with the nasopharynx - pharyngeal branches of the maxillary nerve and artery.
  4) Inferior orbital fissure - bony orbit to pterygoid canal
• zygomatic branch of maxillary nerve
• infraorbital artery and vein
  5) Greater palatine canal - communicates with oral cavity.
• Descending palatine artery and vein
• Greater and lesser palatine nerves
  6) Sphenopalatine foramen - to the nasal cavity
• Sphenopalatine artery and vein
• Nasopalatine nerve

Question 8

Clinical relevance - maxillary nerve block

Answer 8

Requires total block of the maxillary branch of the trigeminal nerve.

Approached intraorally via the greater palatine canal.

Question 9

Clinical relevance - chronic epistaxis

Answer 9

The sphenopalatine artery is the known as the artery of epistaxis (nosebleed).

Treatment - artery can be ligated within the pterygopalatine fossa, via the maxillary sinus, to control bleeding.