The pterygopalatine fossa is a bilateral, cone-shaped depression that extends from the infratemporal fossa deep into the nasal cavity via the sphenopalatine foramen. It is located between the maxilla, sphenoid and palatine bones and communicates with other regions of the skull and facial skeleton through several canals and foramina. Its small volume and the multiple structures passing through the region make it a complex area for anatomy students to learn.
This article will discuss the pterygopalatine fossa and cover the structures involved according to their respective foramina.
The borders of the pterygopalatine fossa are formed by:
The pterygopalatine fossa contains several important neurovascular structures such as the maxillary nerve and its branches, the pterygopalatine ganglion, and the maxillary artery and its branches.
The maxillary nerve (CNV2) is the second branch of the trigeminal nerve and passes from the middle cranial fossa into the pterygopalatine fossa through the foramen rotundum. Once in the fossa, the main trunk leaves the pterygopalatine fossa via the infraorbital fissure, enters the infraorbital canal of the maxilla, and exits below the orbit in the infraorbital foramen to contribute to the sensory innervation of the face.
The maxillary nerve gives off several branches while in the pterygopalatine fossa, including the infraorbital, zygomatic, nasopalatine, superior alveolar, pharyngeal, and greater and lesser palatine nerves. It also communicates with the pterygopalatine ganglion (discussed below) through two small trunks called the pterygopalatine nerves, which suspend the ganglion in the fossa.
The pterygopalatine ganglion is located deep within the pterygopalatine fossa near the sphenopalatine foramen, and is the largest parasympathetic ganglion related to the branches of the maxillary nerve (via pterygopalatine branches) and is predominantly innervated by the greater petrosal branch of the facial nerve (CNVII).
Postsynaptic parasympathetic fibres leave the ganglion and distribute with branches of the maxillary nerve (CNV2). These fibres are secretomotor in function, providing parasympathetic innervation to the lacrimal gland and muscosal glands of the oral cavity, nose, and pharynx.
The maxillary artery is a terminal branch of the external carotid artery, with its terminal portion located in the pterygopalatine fossa. Here, it divides into several branches and passes through other openings in the fossa to reach the regions it supplies.
Branches of the maxillary artery and related foramina and cavities include the sphenopalatine artery to the nasal cavity, the descending palatine artery to the hard and soft palates, the infraorbital artery to the lacrimal gland and muscles of the eye, and the posterior superior alveolar artery to the teeth and gingiva. At their terminal ends, the sphenopalatine and greater palatine arteries anastomose at the nasal septum.
The pterygopalatine fossa has seven openings (foramina) connecting it to the orbit, nasal and oral cavities, middle cranial fossa, and infratemporal fossa. These openings transmit blood vessels and nerves between the aforesaid regions.
The pterygomaxillary fissure connects the infratemporal fossa to the pterygopalatine fossa.
The pterygopalatine fossa is an anatomically important region in the human body located at the base of the skull. It is bounded by the palatine, maxilla and sphenoid bones and consists of three openings - the foramen rotundum, the pterygoid canal, and the pharyngeal canal - that transport two neurovascular structures: the posterior superior alveolar nerve, a branch of the maxillary nerve, and the terminal part of the maxillary artery.
The foramen rotundum connects the pterygopalatine fossa to the middle cranial fossa, and it carries the maxillary nerve. The pterygoid canal and pharyngeal canal are the other two openings in the posterior wall of the pterygopalatine fossa. The pterygoid canal runs from the middle cranial fossa and through the medial pterygoid plate, carrying the nerve, artery and vein of the pterygoid canal. The pharyngeal canal communicates with the nasopharynx and carries the pharyngeal branches of the maxillary nerve and artery.
The inferior orbital fissure is found in the superior boundary of the pterygopalatine fossa and connects it to the orbit. It is a space between the sphenoid and maxilla bones, and the zygomatic branch of the maxillary nerve and the infraorbital artery and vein pass through the inferior orbital fissure.
The greater palatine canal is situated in the inferior boundary of the pterygopalatine fossa, and it communicates with the oral cavity. It transmits the descending palatine artery and vein, the greater palatine nerve and the lesser palatine nerve.
The sphenopalatine foramen is the only opening in the medial boundary, linking the pterygopalatine fossa to the nasal cavity. It carries the sphenopalatine artery and vein, as well as the nasopalatine nerve.
Clinical relevance of the pterygopalatine fossa is evidenced in maxillary nerve block for extensive dental surgery and the sphenopalatine artery (artery of epistaxis) in cases of chronic epistaxis.
The pterygopalatine fossa is bordered by the palatine, maxilla and sphenoid bones. The anterior boundary is the posterior wall of the maxillary sinus, the posterior boundary is the pterygoid process of the sphenoid bone, the inferior boundary is the palatine bone and palatine canals, the superior boundary is the inferior orbital fissure of the eye, the medial boundary is the perpendicular plate of the palatine bone, and the lateral boundary is the pterygomaxillary fissure.
The pterygopalatine fossa is home to numerous important neurovascular structures, including the maxillary nerve and its branches, the pterygopalatine ganglion, and the maxillary artery and its branches.
The maxillary nerve is the second branch of the trigeminal nerve (CNV2). It leaves the middle cranial fossa and enters the pterygopalatine fossa through the foramen rotundum. The main trunk of the maxillary nerve then leaves the pterygopalatine fossa via the infraorbital fissure, passing through the infraorbital canal of the maxilla and exiting below the orbit in the infraorbital foramen where it contributes to the sensory innervation of the face (Figures 2.0 and 2.1).
While in the pterygopalatine fossa, the maxillary nerve gives off numerous branches, including the infraorbital, zygomatic, nasopalatine, superior alveolar, pharyngeal and the greater and lesser palatine nerves. In addition, the maxillary nerve is connected to the pterygopalatine ganglion (discussed below) via two small trunks, the pterygopalatine nerves (Figure 2.1). These nerves suspend the ganglion within the pterygopalatine fossa.
The pterygopalatine ganglion is the largest parasympathetic ganglion related to branches of the maxillary nerve (via pterygopalatine branches) and is located deep within the pterygopalatine fossa near the sphenopalatine foramen. It is predominantly innervated by the greater petrosal branch of the facial nerve (CNVII).
Once synapsed, parasympathetic fibres leave the ganglion and distribute through different branches of the maxillary nerve (CNV2). These fibres are secretomotor in function, providing parasympathetic innervation to the lacrimal gland and muscosal glands of the oral cavity, nose and pharynx.
The maxillary artery is a terminal branch of the external carotid artery. The terminal portion of the maxillary artery lies within the pterygopalatine fossa and separates into several branches which travel through other openings of the fossa to reach the regions they supply.
These branches include, but are not limited to, the sphenopalatine artery (to the nasal cavity).
The Pterygopalatine Fossa is a space in the head located between the maxilla and palatine bones and is bound by the maxilla, palatine, and sphenoid bones. Its borders are the pterygomaxillary fissure on the anterior wall, the foramen rotundum on the posterior wall, the inferior orbital fissure on the superior wall, and the sphenopalatine foramen on the medial wall.
The pterygopalatine fossa houses an array of structures including the pterygopalatine ganglion, the maxillary nerve and its branches, the maxillary artery and its branches, the accessory lesser palatine canals, and the descending palatine artery and vein.
The descending palatine artery branches into the greater and lesser palatine arteries and is responsible for supplying blood to the hard and soft palates. The infraorbital artery supplies blood to the lacrimal gland, and some muscles of the eye. The posterior superior alveolar artery provides a blood supply to the teeth and gingiva. At their terminal ends, the sphenopalatine and greater palatine arteries anastomose at the nasal septum.
In addition to the descending palatine artery and other structures, the pterygopalatine fossa is connected to other regions of the head and neck via seven openings (also known as foramina). These openings transmit blood vessels and nerves between the pterygopalatine fossa, the orbit, nasal and oral cavities, the middle cranial fossa, and the infratemporal fossa.
The pterygomaxillary fissure connects the infratemporal fossa with the pterygopalatine fossa and is located between the maxilla and palatine bones (see figure 1).
Maxillary nerve block is a technique used extensively during dental surgery to block the maxillary branch of the trigeminal nerve (CNV2). The maxillary nerve is located in the pterygopalatine fossa and is most often approached intraorally via the greater palatine canal.
The sphenopalatine artery is often referred to as the “artery of epistaxis” in cases where a person suffers from chronic nosebleeds. In these cases, the pterygopalatine fossa can be surgically approached via the maxillary sinus, and the artery ligated to control the bleeding.
