Palatine Bone Definition

The palatine bone, also known as the os palatinum, is a flat, uneven facial bone that is paired. It is found in the nasal cavity, oral cavity, and orbit of the eye. Each bone is made up of two plates that lie between the processes of the right and left maxilla bones, as well as the single sphenoid bone. The larger and smaller palatine canals are connected by foramina in paired palatine bones. Blood vessels and nerves may pass via these canals.

Palatine Bone Location

Running the tongue toward the back of the neck, halting just before hard and soft tissue meet, the palatine surface of the horizontal plate (see palatine bone structure) that forms the rear part of the hard palate (palate-palatine) may be felt (see palatine bone anatomy).

The apex of the palatine tonsils, which contain lymphoid tissue lumps on either side of the back of the throat, shows the palatine bone basis.

Each (facial) palatine bone is shaped like an L. Because one bone is a mirror replica of the other, the horizontal lines (horizontal plates) of the two Ls meet. Each horizontal plate’s front segment articulates with a portion of the maxilla. The pharyngeal cartilage joins the rear of the horizontal plates (posterior boundary).

The perpendicular plate of the palatine bone is the vertical line of the L. This plate may be found behind the nasal conchae. The inferior nasal concha and sphenoid bone articulate with both plates that go up from the horizontal plate. The placements of the three nasal conchae are shown below.

Palatine Bone Anatomy

The perpendicular plate and the horizontal plate are the two subclasses of palatine bone structure; keep in mind that these are left and right paired bones.

The picture below depicts labelled palatine bones that are mirror reflections of one another.Consider the spongy tissue of the nose between them. Numerous anatomical structures are identified.

1. Perpendicular plate of the palatine bone
2. Horizontal plate of the palatine bone
3. Articulation point of both palatine bones to form the nasal crest
4. Conchal crest that meets the inferior nasal concha
5. Various parts of the pyramidal process
6. Sphenoidal process
7. Various parts of the orbital process
8. Insertions of muscles that raise the uvula
9. Insertion of the superior pharyngeal constrictor muscle
10. Insertion for the medial pterygoid muscle.

Perpendicular Plate of the Palatine Bone

In the perpendicular plate, which is perpendicular, there are two working surfaces. These are the nasal and maxillary surfaces.

The os palatinum’s maxillary surface contacts the maxilla bone’s nasal surface and the sphenoid bone’s pterygoidian process.

Because of the uneven nature of these bones’ junction, room is created towards the pterygopalatine fossa. The pterygopalatine fossa is a space that allows vital nerve tissue like the maxillary nerve and the pterygopalatine ganglion to pass through. These nerves provide information to the skin of the temples, the upper lip, and the teeth. The maxillary artery and several veins are likewise housed in the pterygopalatine fossa. Pterygo means “winged creature.”

The orbital process is located near the top of the perpendicular plate. This section of the os palatinum is attached to the eye socket. The orbital process is a little below the sphenoidal process. This procedure is not just a component of the bony nasal cavity. This process encircles the sphenopalatine foramen, which connects the nasal cavity to the pterygopalatine fossa and encapsulates it into the pterygoid plates of the sphenoid bone.

The maxillary sinus wall includes other elements of the os palatinum’s maxillary surface.

Small holes called foramina may also be seen in the perpendicular plates. When the maxilla lies on top of the larger palatine foramen, it creates a channel by forming a groove (canal). The rear of the hard palate contains both the bigger palatine foramina (due to the fact that humans have two palatine bones). The bigger palatine canal is reached by them. The larger palatine nerve and its blood supply are protected by this canal. The lesser palatine nerves are located in the lesser palatine canals. The hard and soft palates, tonsils, and nasal cavity are all innervated by the lesser and greater nerves.

Below are two sets of larger and smaller palatine foramina circled in pink (not red).

The perpendicular plate’s nasal surface, as its term implies, confronts the nasal cavity. At the rear of the nose, this part of the palatine bone’s perpendicular plate provides structure.

The palatine bone’s pyramidal process is located between the horizontal and perpendicular plates. It fits between the two thin plates in the sphenoid bone termed the pterygoid plates to produce the pterygoid (not the pterygopalatine) fossa. The pterygoid fossa serves as a home for masticatory muscles, or chewing muscles.

On the palatine bones’ horizontal plates can be seen, which run across the pyramidal processes and through the interior of each pterygoid fossa.

Horizontal Plate of the Palatine Bone

The horizontal plate of the oral cavity may be felt at the rear of the hard palate. It is also a component of the nasal cavity’s bottom. This plate has two surfaces, much like the perpendicular plate. The nasal and palatine (palate) surfaces are seen here.

Every straight plate of the palatine bone meets its mirror counterpart at a somewhat broader angle than the others. The nasal spine and nasal crest are formed from the broader portion.

When the horizontal plate reaches the pyramidal process of the perpendicular plate of the palatine bone, it comes to a stop – the pyramidal process is a portion of the perpendicular plate, perhaps not the horizontal plate.

Palatine Bone Function

Palatine bone has three functions. To begin, each bone offers partial surfaces for the hard palate on the roof of the mouth, the nasal cavity, and the orbit bones.

The hard palate is formed by the palatine process of the maxilla as well as the straight plates of the palatine bones. It is the roof of the oral cavity and the floor of the nasal cavity.

The orbit bones are made up of seven facial bones (palatine included). The orbit’s floor is made up of pieces of the zygomatic, maxillary, and palatine bones (bottom). The multiple faint fissures in the eye sockets below reveal where these different bones articulate.

The air we breathe is warmed and humidified by the nasal cavity, which also retains germs and contaminants. The nasal canal is divided into two nasal chambers by the cartilaginous septum, despite the fact that humans only have one nose. The palatine process of the maxilla bone and the straight plate of the palatine bone make up the nasal cavity floor.

The os palatinum also serves as a site of attachment for facial muscles. The palatine bone is attached to four muscles:

• Pterygoid medial muscle (towards the pyramidal process)
• The superior pharyngeal constrictor muscle (towards the horizontal plate)
• Palati tensor (towards the horizontal plate)
• Muscle uvula (towards the horizontal plate)

As a result, three foramina in the palatine face bone enable nerves and blood vessels to pass through. The hard and soft palates, as well as the nasal cavity, are served by these nerves, which supply sensory and motor pathways.

There are three foramina on each bone:

• In between the pterygopalatine fossa as well as the oral cavity, the greater palatine nerve and blood vessels pass via the greater palatine foramen.
• The lesser palatine canal and the oral cavity form the lesser palatine foramen, which serves as a passageway for the lesser palatine nerve and blood vessels.
• Between the pterygopalatine fossa and the nasal cavity, the sphenopalatine artery and vein, the nasopalatine nerve, and the nasal nerves pass via the sphenopalatine foramen.

Palatine Process vs Palatine Bone

The difference between the palatine process and palatine bone is simple: palatine bones have no palatine processes. The palatine processes connect the adjoining maxilla bones to the palatine bones.

There are three processes on the palatine bone. To prevent misunderstanding, these processes should always be referred to by the name of the bone from which they arise (in this example, the palatine bone). The three procedures are as follows:

• The palatine bone’s orbital process (a component of the orbital bone)
• The palatine bone’s pyramidal process (a component of the pterygoid fossa)
• The palatine bone’s sphenoid process (a component of the pterygopalatine fossa)

Whenever you see the term “process” in a book on facial bone anatomy, you understand it relates to an area or protrusion that connects to the bone it is named for.

The inclusion of ‘of the’ – for example, the palatine bone’s orbital process – demonstrates that this process extends from the palatine bone to the orbital bone. Because the frontal bone contains two orbital processes, it’s vital to indicate the origin bone.

The palatine process of the maxilla bone therefore indicates that the os palatinum has a protrusion from the maxilla that contributes to its construction or function.

References

• Helwany M, Rathee M. (Updated 2020). Anatomy, Head and Neck, Palate. Treasure Island (FL): StatPearls Publishing. Retrieved from: https://www.ncbi.nlm.nih.gov/books/NBK557817/
• Sobiesk JL, Munakomi S. Anatomy, Head and Neck, Nasal Cavity. [Updated 2019 Jun 26]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2020 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK544232/