In this article we will discuss about:- 1. Introduction to Pterygo Palatine Fossa 2. Communications of Pterygo Palatine Fossa 3. Contents of Pterygo Palatine Fossa.
Introduction to Pterygo Palatine Fossa:
It is a pyramidal shaped space situated deep to infra temporal fossa, below the apex of the orbit. This fossa is concerned with blood and nerve supply of upper jaw, nose, nasopharynx and lacrimal gland.
Boundaries:
Anterior:
Medial part of the posterior surface of maxilla.
Posterior:
Anterior surface of root of pterygoid process and adjoining part of sphenoid bone.
It presents with three openings in the posterior wall:
1. Foramen rotundum connects it with middle cranial fossa.
2. Anterior opening of pterygoid canal connects it with foramen lacerum.
3. Palato vaginal canal connects it with nasopharynx.
Superior:
Inferior surface of body of sphenoid bone. Inferior orbital fissue connects it with orbit.
Inferior:
This is the apex of the fossa and is formed by meeting of the anterior and posterior boundaries, inferiorly in between them lies pyramidal process of palatine bone.
Greater and lesser palatine canals are present inferiorly between the junction connects it with oral cavity.
Medial:
Perpendicular plate of palatine bone – posterosuperior part of lateral surface.
Lateral:
Pterygomaxillary fissure connects it with infratemporal fossa.
Communications of Pterygo Palatine Fossa:
1. Through foramen rotundum the maxillary nerve enters in this fossa and it communicates with middle cranial fossa.
2. Pterygoid canal – through this nerve and artery of pterygoid canal are passing and the fossa communicates with foramen lacercum.
3. Palatino vaginal canal – fossa communicates with roof of nasopharynx and pharyngeal nerves and a vessel passes through this canal to supply mucous membrane of nasopharynx.
4. Inferior orbital fissure – fossa communicates to orbital cavity anteriorly. Infra orbital nerve and vessels passes through this fissure.
5. Pterygo maxillary fissure – through this fossa communicates laterally to infratemporal fossa.Third part of maxillary artery enters in the fossa through this fissure.
6. Via spheno palatine foramen situated in the medial wall, fossa communicates with nasal cavity. Spheno palatine artery and nasopalatine nerve passes through this foramen and enters the nose.
7. Through greater and lesser palatine canal situated inferiorly, fossa communicates with oral cavity. Greater and lesser palatine nerve and blood vessels passes through these canals.
Contents of Pterygo Palatine Fossa:
1. Maxillary nerve and its branches.
2. Pterygopalatine ganglion and its branches.
3. Third part of maxillary artery and its branches.
I. Maxillary Nerve (V2):
This is a sensory nerve.
Commencement:
From anterior border of trigeminal ganglion.
Course:
It passes forwards and laterally and enters the lateral wall of cavernous sinus.
It leaves the cranial cavity through foramen rotundum and enters the pterygo palatine fossa.
It then enters the orbit through inferior orbital fissure. The nerve is accompanied by the infra orbital artery. The part of this nerve in the floor of the orbit is called infra-orbital nerve. Here the nerve passes within the infra orbital canal and leaves the orbit through the infra orbital foramen and enters the face.
Termination:
It terminates by dividing into following branches:
(a) Palpebral branch
(b) Nasal branch
(c) Labial branch.
Branches:
(a) Within the Cranial Cavity:
Meningeal branch which supplies meninges of middle cranial fossa.
(b) Within the Pterygo Palatine Fossa:
(i) 2 or 3 ganglionic branches to join pterygo palatine ganlion.
(ii) Zygomatic nerve divides into zygomaticotemporal and zygomaticofacial nerve.
(iii) Posterior superior alveolar nerve.
(c) Branches of V2 Nerve within the Floor of the Orbit:
(i) Middle superior alveolar nerve
(ii) Anterior superior alveolar nerve.
(d) On the Face:
(i) Palpebral branch
(ii) Nasal branch
(iii) Labial branch
The posterior, middle and anterior superior alveolar nerves enter the maxilla and they form the superior dental plexus to supply teeth of the upper jaw and maxillary air sinus.
II. Pterygo Palatine Ganglion:
Spheno-palatine ganglion or Meckel’s ganglion or ganglion of Hey fever.
Situation:
Pterygo palatine fossa.
Roots:
Sympathetic and parasympathetic roots – Via nerve of pterygoid canal. It is formed by deep petrosal nerve from sympathetic plexus around internal carotid artery and greater superficial petrosal nerve from the geniculate ganglion of facial nerve unite to form the nerve of pterygoid canal also called as Vidian’s nerve.
Sensory Root:
Maxillary nerve via its ganglionic branches.
Branches from the Ganglion:
1. Orbital branches – supplies orbital periosteum and orbitalis muscle.
2. Greater and lesser palatine nerves – supplies mucous membrane of hard and soft palate.
3. Naso palatine nerve – to supply mucous membrane of medial and lateral wall of nose and anterior part of hard palate.
4. Nasal branches to nose – medial and lateral walls.
5. Pharyngeal branches to mucosa of nasopharynx.
6. Parasympathetic fibres to lacrimal gland – these fibres enters the maxillary nerve – pass through its zygomatico temporal branch – ultimately these fibres leave the zygomatico temporal nerve and join lacrimal nerve and finally reaches the lacrimal gland. These are secretomotor fibres for the gland.
Applied:
Stimulation of pterygo palatine ganglion causes nasal – Catarrh and lacrimation.
III. Third Part of Maxillary Artery:
Enters the pterygo palatine fossa through lower part of pterygo maxillary fissure.
It ascends upwards, medially and continued as sphenopalatine artery – which passes through sphenopalatine foramen and enters the nasal cavity to supply it.
Branches of this part accompanies the branches of maxillary nerve and pterygo palatine ganglion:
1. Posterior superior alveolar artery
2. Infra orbital artery
3. Greater and lesser palatine arteries
4. Pharyngeal artery
5. Artery of pterygoid canal
6. Spheno palatine artery.