The posterior superior alveolar nerves (also posterior superior dental nerves or posterior superior alveolar branches) are sensory branches of the maxillary nerve (CN V₂). They arise within the

pterygopalatine fossa In human anatomy, the pterygopalatine fossa (sphenopalatine fossa) is a fossa in the skull. A human skull contains two pterygopalatine fossae—one on the left side, and another on the right side. Each fossa is a cone-shaped paired depression dee ...

as a single trunk. They run on or in the maxilla. They provide sensory innervation to the upper molar teeth and adjacent gum, and the

maxillary sinus The pyramid-shaped maxillary sinus (or antrum of Nathaniel Highmore (surgeon), Highmore) is the largest of the paranasal sinuses, located in the maxilla. It drains into the middle meatus of the noseHuman Anatomy, Jacobs, Elsevier, 2008, page 209- ...

Anatomy

Origin

The nerves arise from the trunk of the maxillary nerve (CN V₂) within the

just before it enters the

infraorbital groove The infraorbital groove (or sulcus) is located in the middle of the posterior part of the orbital surface of the maxilla. Its function is to act as the passage of the infraorbital artery, the infraorbital vein, and the infraorbital nerve. Struc ...

. The nerve arises as a single trunk which split into 2-3 nerves within the pterygopalatine fossa.

Course

The nerves exit the pterygopalatine fossa through the

pterygomaxillary fissure The pterygomaxillary fissure is a fissure of the human skull. It is vertical, and descends at right angles from the medial end of the inferior orbital fissure. It is a triangular interval, formed by the divergence of the maxilla from the pterygoi ...

. They pass within or upon the posterior wall of the maxilla. They descend on the tuberosity of the

maxilla In vertebrates, the maxilla (: maxillae ) is the upper fixed (not fixed in Neopterygii) bone of the jaw formed from the fusion of two maxillary bones. In humans, the upper jaw includes the hard palate in the front of the mouth. The two maxil ...

and give off several twigs to the

gums The gums or gingiva (: gingivae) consist of the mucosal tissue that lies over the mandible and maxilla inside the mouth. Gum health and disease can have an effect on general health. Structure The gums are part of the soft tissue lining of the ...

and neighboring parts of the

mucous membrane A mucous membrane or mucosa is a membrane that lines various cavities in the body of an organism and covers the surface of internal organs. It consists of one or more layers of epithelial cells overlying a layer of loose connective tissue. It ...

of the

cheek The cheeks () constitute the area of the face below the eyes and between the nose and the left or right ear. ''Buccal'' means relating to the cheek. In humans, the region is innervated by the buccal nerve. The area between the inside of th ...

. They then enter the alveolar canals on the infratemporal surface of the

, and, passing from behind forward in the substance of the bone, communicate with the middle superior alveolar nerve, and give off branches to the lining membrane of the

and gingival and dental branches to each

molar tooth The molars or molar teeth are large, flat teeth at the back of the mouth. They are more developed in mammals. They are used primarily to grind food during chewing. The name ''molar'' derives from Latin, ''molaris dens'', meaning "millstone toot ...

from a superior dental plexus; these branches enter the apical foramina at the roots of the teeth.

Distribution

The nerves provide sensory innervation to the upper/maxillary molar teeth and the associated

gingiva The gums or gingiva (: gingivae) consist of the mucosal tissue that lies over the mandible and maxilla inside the mouth. Gum health and disease can have an effect on general health. Structure The gums are part of the soft tissue lining of the ...

of the vestibule, and the

Teeth

The nerve innervates the second and third maxillary/upper molar teeth, and two of the three roots of the maxillary/upper first molar tooth (all but the mesiobuccal root).

Clinical significance

When giving a posterior superior alveolar nerve block, it will anesthetize the mesialbuccal root of the maxillary/upper first molar tooth approximately 72% of the time.

Anatomy

Origin

Course

Distribution

Teeth

Clinical significance

See also

Additional images

References

External links