Anatomy of the Head and Neck

lecture 16

Abbas A. A. Shawka

Medical student

2nd stage

Subjects

Pterygopalatine fossa

Pterygopalatine fossa • inverted teardrop-shaped space

between bones on the lateral side of the skull immediately posterior to the maxilla

• Although small in size, the pterygopalatine fossa communicates via fissures and foramina in its walls with the :

1. middle cranial fossa.

2. infratemporal fossa.

3. floor of the orbit.

4. lateral wall of the nasal cavity.

5. Oropharynx.

6. roof of the oral cavity.

Pterygopalatine fossa

• Walls of this fossa are :-

1. The anterior wall is formed by the posterior surface of the maxilla.

2. The medial wall is formed by the lateral surface of the palatine bone.

3. The posterior wall and roof are formed by parts of the sphenoid bone.

Posterior wall • The part of sphenoid bone that contribute to the posterior wall of this fossa is the

anteriosuperior aspect of the root of pterygoid processes !!

• This surface has two important foraminae …

1

2

• Foramina rotundum : - between pterygopalatine fossa and MCF

• Pterygoid canal

- Between pterygopalatine fossa and MCF

- Bony canal lie horizontally through the roots of pterygoid processes in sphenoid bone.

- Continous with the cartilage filling the foramen lacerum to open in the MCF

Gateways

1. The foramen rotundum and pterygoid canal communicate with the middle cranial fossa and open onto the posterior wall.

2. A small palatovaginal canal opens onto the posterior wall and leads to the nasopharynx.

3. The palatine canal leads to the roof of the oral cavity (hard palate) and opens inferiorly.

4. The sphenopalatine foramen opens onto the lateral wall of the nasal cavity and is in the medial wall.

1

2

3

4

Gateways

5. The lateral aspect of the pterygopalatine fossa is continuous with the infratemporal fossa via a large gap (the pterygomaxillaryfissure) between the posterior surface of the maxilla and pterygoid process of the sphenoid bone.

6. The superior aspect of the anterior wall of the fossa opens into the floor of the orbit via the inferior orbital fissure.

6

5

Contents

1. maxillary nerve V2 and its branchs

2. terminal branches of maxillary artery

3. pterygopalatine ganglion

Maxillary nerve : • Exit the MCF through foramina rotundum …

• 1- orbital branches to supply the orbital wall , sphenoidal and ethmoidal sinuses.

• 2- greator and lesser palatine nerves ( TO ORAL CAVITY ) ( note :- gratorpalatine n. posterior inferior nasal nerves )

• 3- nasal nerves :- supply the lateral wall of nasal cavity and some cross the roof to innervate the medial wall , one of the branches ( nasopalatine n. ) pass through the incisive canal to innervate incisive teeth and gingiva and glands adjacent to incisive teeth

• 4- pharyngeal nerve :-to supply mucosa and glands of nasopharynx.

• 5- zygomatic nerves :- pass through the lateral wall of orbit then divide into zygomatictemporal and zygomaticofascial

• 6- posterior superior alveolar nerve

• 7- inferior orbital nerve :- wich then give middle and anterior superior alveolar nerves

Maxillary nerve :

Pterygopalatine ganglia

Pterygopalatine ganglia

• Sympathetic :- deep petrosal n. From ICA

• Parasympathetic :- great petrosal n. from VII

• Deep petrosal n. + great petrosal n. = nerve to pterygoid canal ( carry sympathetic & parasympathetic fibers to pterygopalatine ganglia …

• Sympathetic without relay !!!

Branches of maxillary artery

• branch of maxillary a. in this fossa ….

• 1- posterior superior alveolar a.

• 2- infra-orbital a. gives anterior superior alveolar a.

• 3- grator palatine artery

• 4- Pharyngeal branch :- supplies the posterior aspect of the roof of the nasal cavity, the sphenoidal sinus, and the pharyngotympanic tube.

• 5- sphenopalatine a.

• 6- artery to pterygoid canal

• NEXT SLIDE …

Venous drainage • Veins that drain areas supplied by

branches of the terminal part of the maxillary artery generally travel with these branches back into the pterygopalatine fossa.

• The veins coalesce in the pterygopalatine fossa and then pass laterally through the pterygomaxillaryfissure to j oin the pterygoid plexus of veins in the infratemporal fossa.

• The infra-orbital vein, which drains the inferior aspect of the orbit, may pass directly into the infratemporal fossa through the lateral aspect of the inferior orbital fissure, so bypassing the pterygopalatine fossa.