The palatine bone is a thin paired bone that primarily participates in forming the hard palate. Therefore it also forms a small part of the floor of the nasal and the roof of the oral cavities, as well as participates in forming the pterygopalatine and pterygoid fossae and the orbit.

It is located between maxillae and sphenoid bone (the pterygoid process of it).

Each palatine bone is located in the posterior part of the nasal cavity and consists of two plates:

Horizontal plate - forms the posterior portion of both the hard palate and the floor of the nasal cavity;
Perpendicular plate - the vertical part, which forms part of the medial wall of the maxillary sinus and part of the lateral wall of the nasal cavity; it is located anterior to the medial plate of the pterygoid process; it also separates the nasal cavity from the pterygopalatine fossa.

Horizontal plate

The horizontal plate participates in forming the hard palate, and it is located in the transverse plane. It has two surfaces - nasal surface (superior) facing the nasal cavity and palatine surface (inferior) facing the oral cavity.

Besides surfaces, the palatine bone has four borders:

Posterior to the nasal crest in the midline is located a bony projection called the posterior nasal spine. Both medial ends of the posterior border are sharp and pointed, and by fusing together, they form the spine. It is an attachment site for the uvular muscle.

The horizontal plate has an opening called the greater palatine foramen leading into the greater palatine canal, which transmits the greater palatine nerve and blood vessels. It is located on the lateral border.

Perpendicular plate

The perpendicular plate is located in the sagittal plane. It starts from the lateral border of the horizontal plate, and by forming a straight angle, it goes in a superior direction. Similar to the horizontal plate, the perpendicular plate also has two surfaces - the nasal surface facing the nasal cavity and the maxillary surface facing the maxilla.

The nasal surface forms a part of the lateral wall of the nasal cavity. This surface contains two ridges or crests named the conchal and ethmoidal crests. The conchal crest is located in the lower two-thirds of the plate, while the ethmoidal crest is more in its superior part.

The conchal crest connects with the inferior nasal concha, but the ethmoidal crest is attached to the middle nasal concha. Between both crests and below the conchal crest, the nasal surface has two concavities corresponding to the inferior and middle nasal meatuses.

The maxillary surface participates in forming the medial wall of the pterygopalatine fossa and maxillary sinus.

The perpendicular plate has four borders:

Processes of the palatine bone

The palatine bone has three processes, named the pyramidal, orbital and sphenoidal processes.

The pyramidal process is located posterolaterally from the junction site between the horizontal and perpendicular plates. It arises from the inferior aspect of the posterior border of the perpendicular plate. The pyramidal process also participates in the formation of the pterygoid fossa together with both plates of the pterygoid process of the sphenoid bone as it is located between them.

The superficial head of the medial pterygoid muscle originates from the lateral aspect of this process. The inferior surface of the pyramidal process contains small openings situated posterior to the greater palatine foramen. They are called lesser palatine foramina leading to the lesser palatine canals that transmit lesser palatine nerves and blood vessels.

The orbital process arises from the anterior aspect of the superior border of the perpendicular plate. It goes in a superior direction and participates in forming a small part of the floor of the orbit, the pterygopalatine fossa, as well as the inferior orbital fissure. The orbital process has several articular surfaces for articulation with the sphenoid and ethmoid bones, maxilla, and sometimes it also articulates with the frontal bone.

The sphenoidal process arises from the superior aspect of the posterior border of the perpendicular plate. It goes in a superomedial direction. Its posterior border has a connection with the medial plate of the pterygoid process, its medial border connects with the vomer, while its anterior border forms the posterior aspect of the sphenopalatine notch located on the superior border of the palatine plate.

Sutures

Several sutures can be found on the palatine bones.

The first one is a sagittal-oriented median palatine suture connecting both palatine bones in the midline. It extends from both maxillae to the bones. Therefore, also maxillae contain this suture.

The second suture is a horizontal-oriented transverse palatine suture separating the palatine process of the maxillae from the horizontal plates of the palatine bones.

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Palatine bone