Download Pterygo Fossa - Dr. Meredith

Pterygopalatine Fossa Alex Meredith, PhD The ptergopalatine fossa is located medial (deep) to the infratemporal region. From a lateral view, its shape can be thought to outline a quadrilateral whose inferior aspect is narrower than its top. The walls of the pterygopalatine fossa can be imagined to be constituted by four such quadrilaterals. The pterygopalatine fossa contains the pterygopalatine ganglion, nerve branches to and from the ganglion, and the third part of the maxillary artery and its branches. Fig 1 Roof: None, but is related, superiorly, to the greater wing of sphenoid.
Walls: each is formed by portions of two cranial bones: 1. Lateral: Pterygoid plate, posteriorly Maxilla, anteriorly 2. Anteriorly: Maxilla, laterally Palatine, medially 3. Medial: Palatine, anteriorly Body of Sphenoid, posteriorly 4. Posterior: Body of Sphenoid, medially Pterygoid plate, laterally Floor: None, but the fossa is directly continuous with a canal in the palatine bone (“palatine canal”) that leads inferiorly to the greater and lesser palatine foramina. Foramina: 1. Lateral: Pterygomaxillary fissure, the opening between the pterygoid plate and posterior surface of the maxilla. 2. Anterior: Inferior orbital fissure: a groove in the maxilla 3. Medial: Sphenopalatine foramen: the body of the sphenoid bone meets a notch in the palatine bone. 4. Posterior: a. Pharvngeal canal (often a groove): at the juntion of posterior and medial walls, runs posterior medial direction towards the nasopharynx and auditory tube. b. Pterygoid canal: runs posteriorly through the base of the phenoid sinus. c. Foramen rotundum: enters postero­superiorly.
Fig 2 Numbers 1­14 below correspond with figure 2. 1. Maxillary a., enters through pteygomaxillary fissure. 2. Posterior superior alveolar a., exits pterygomaxillary fissure, runs on posterior surface of maxilla, enters unnamed foramen to distribute to maxillary sinus and the alveolar process. 3. Infraorbital a., leaves fossa though inferior orbital fissure, runs along groove in maxilla while supplying orbital branches (4) and anterior superior alveolar a (5) before exiting the infraorbital foramen to supply the face. 4. Orbital branches
5. Anterior superior alveolar a. supplies the maxillary sinus and the alveolar process near the incisors. 6. Desending palatine a. leavesthe fossa inferiorly and divides into anterior greater palatine (7) and posterior lesser palatine (8), arteries. 7. Greater palatine a. supplies the hard palate and anastomoses with nasopalatine a. (12) through the incisive foramen. 8. Lesser palatine a. supplies the soft palate. 9. Sphenopalatine a. exits medially through the sphenopalatine foramen and gives off branches 10­12. 10. Lateral posterior nasal aa. 11. Medial posterior nasal aa. ramify on septum. 12. Nasopalatine a. courses along a groove on vomer and anastomoses with greater palatine a. through the incisive canal. 13. Pharyngeal a. is a small artery that courses through the pharyngeal canal (groove) to supply the nasopharynx. 14. Artery of the pterygoid canal passes posteriorly to supply the auditory tube, middle ear and pharynx.
Fig 3 Numbers 1 ­ 23 below correspond with figure 3. Trigeminal ganglion 1. Maxillary nerve 2. Infraorbital nerve 3. Posterior superior alveolar nerve 4. Pterygopalatine nn. 5. Pterygopalatine ganglion 6. Nerve of the pteygoid canal 7. Greater (superficial) petrosal nerve 8. Deep pertrosal nerve 9. Facial nerve
10. Greater palatine nerve 11. Lesser palatine nerve 12. Lateral posterior nasal branches 13. Medial posterior nasal branches 14. Nasopalatine nerve 15. Pharyngeal nerve 16. Orbital nn. 17. Middle superior alveolar nerve (variably present) 18. Anterior superior alveolar nerve 19. Infraorbital nerve on face 20. Zygomatic nerve 21. Zygomaticofacial nerve 22. Zygomaticotemporal nerve 23. Communicating branch to #24 24. Lacrimal n. (from Ophthalmic Division of V) 25. Sphenopalatine nerve thru sphenopalatine foramen
Fig 4 Number 1 ­ 25 below correspond with figure 4. Trigeminal Ganglion 1. Maxillary nerve 2. Infraorbital n. 3. Posterior superior alveolar n. 4. Pterygopalatine nn. 5. Pterygopalatine ganglion 6. Nerve of the pteygoid canal, T** 7. Greater (superficial) petrosal n., T** 8. Deep pertrosal n. 9. Facial nerve, T**
10. Greater palatine n., T** 11. Lesser palatine n. 12. Lateral posterior nasal branches 13. Medial posterior nasal branches 14. Nasopalatine n. 15. Pharyngeal n. 16. Orbital nn. 17. Middle superior alveolar n. (variably present) 18. Anterior superior alveolar n. 19. Infraorbital nerve on face 20. Zygomatic n. 21. Zygomaticofacial n. 22. Zygomaticotemporal n. 23. Communicating branch to #24 24. Lacrimal n. (from Ophthalmic Division of V) 25. Sphenopalatine n.