Palatine bone anatomy: the L-shaped bone at the back of the hard palate

What it is

An L-shaped bone behind the maxilla.

Location

Lies at the back of the nasal cavity and hard palate.

Function

Forms the back of the hard palate and part of the nasal cavity wall and orbit floor.

Body system

Skeletal · paired (left and right)

FMA ID

FMA53656 (Foundational Model of Anatomy)

Key facts

• Its horizontal plate forms the back part of the hard palate (the posterior quarter in OpenStax; some texts say the posterior third).
• Its perpendicular plate forms part of the lateral wall of the nasal cavity, and its small orbital process reaches the floor of the orbit.
• The greater and lesser palatine foramina transmit the palatine nerves and vessels to the palate.

The two palatine bones are L-shaped and meet in the midline. They sit at the back of the nasal cavity, between the maxillae in front and the sphenoid behind. They form the back of the hard palate, which separates the mouth from the nose, and contribute to the floor of the nasal cavity, the floor of the orbit and the pterygopalatine fossa. (Radiopaedia: Palatine bone.)

OpenStax describes the palatine bones as forming the posterior quarter of the hard palate and contributing small areas to the lateral walls of the nasal cavity and the medial wall of each orbit. (OpenStax Anatomy and Physiology 2e, 7.2: The Skull.)

The bone has two plates joined at a right angle, which gives it its L shape. The horizontal plate lies flat and forms the bony core of the posterior quarter of the hard palate, behind the palatine process of the maxilla. The perpendicular plate rises vertically from it. (Kenhub: Palatine bone.)

The perpendicular plate forms the medial wall of the pterygopalatine fossa, separating that fossa from the nasal cavity. Below, the fossa is bounded by the palatine bone and the palatine canals, which lead down to the mouth. (TeachMeAnatomy: The Pterygopalatine Fossa.)

The pterygopalatine fossa that the perpendicular plate walls off is a small but busy space. It contains the maxillary nerve (V2), the pterygopalatine ganglion, which sends secretomotor fibres to the lacrimal gland and the glands of the nose, mouth and pharynx, and branches of the maxillary artery: the sphenopalatine, descending palatine, infraorbital and posterior superior alveolar arteries. (TeachMeAnatomy: The Pterygopalatine Fossa.)

Where the two horizontal plates meet in the midline, together with the maxillae in front, they form a raised nasal crest on the floor of the nose. This bony strip meets the lower margin of the vomer, so the palatine bones also help anchor the nasal septum. (Radiopaedia: Nasal septum.)

On the nasal side, the inferior nasal concha, a separate bone, articulates with the maxilla and the palatine bone. (Radiopaedia: Nasal concha.)

The palatine bone has three processes: pyramidal, orbital and sphenoidal. The pyramidal process carries the lesser palatine foramina. (Kenhub: Palatine bone.)

The small orbital process reaches up to the floor of the orbit. Together with the maxilla it forms the lower border of the inferior orbital fissure. (Radiopaedia: Inferior orbital fissure.)

The sphenoidal process meets the sphenoid bone; the alae of the vomer also articulate with the sphenoidal processes of the two palatine bones. (Radiopaedia: Vomer.)

The greater palatine foramen lies at the back of the hard palate, medial to the third molar. It transmits the greater palatine nerve and vessels, which run forward along the palate. The lesser palatine foramina, in the pyramidal process, transmit the lesser palatine nerves. (TeachMeAnatomy: The Palate.)

The sphenopalatine foramen connects the pterygopalatine fossa with the nasal cavity. It transmits the sphenopalatine artery and vein, the nasopalatine nerve and the posterior superior nasal nerves. (Radiopaedia: Palatine bone.)

The greater palatine canal leads from the pterygopalatine fossa down to the mouth and carries the descending palatine artery and vein and the greater and lesser palatine nerves. (TeachMeAnatomy: The Pterygopalatine Fossa.)

Each palatine bone articulates with the maxilla, the opposite palatine bone, the vomer, the inferior nasal concha, the sphenoid (its body and medial pterygoid plate) and the ethmoid. (Radiopaedia: Palatine bone.)

Three muscles attach to the palatine bone: tensor veli palatini, the muscle of the uvula (musculus uvulae) and the superficial head of medial pterygoid. (Radiopaedia: Palatine bone.)

The palate separates the nasal cavity from the oral cavity. The hard palate in front is bony and immobile: it is formed by the palatine processes of the maxillae and the horizontal plates of the palatine bones. The soft palate behind is mobile and muscular, covered by mucous membrane, and is continuous with the back edge of the hard palate through the palatine aponeurosis. Its free back border carries the uvula. (TeachMeAnatomy: The Palate.)

Five muscles move the soft palate: tensor veli palatini, levator veli palatini, palatoglossus, palatopharyngeus and musculus uvulae. All are supplied by the pharyngeal branch of the vagus nerve except tensor veli palatini, which is supplied by a branch of the mandibular nerve (V3). During swallowing, the soft palate rises to close off the nasopharynx so food does not enter the nose. (TeachMeAnatomy: The Palate.)

The main blood supply of the palate is the greater palatine artery, which runs forward from the greater palatine foramen. The lesser palatine and ascending palatine arteries also contribute. Veins drain to the pterygoid venous plexus. (TeachMeAnatomy: The Palate.)

The names are easily confused. The palatine process belongs to the maxilla: it forms the front three-quarters of the hard palate. The palatine bone is a separate bone whose horizontal plate forms the back quarter. (OpenStax Anatomy and Physiology 2e, 7.2: The Skull.)

The palatine bone ossifies in membrane from about the eighth week of fetal life. At birth its horizontal and perpendicular plates are about equal in size. (Radiopaedia: Palatine bone.)

Dentists can anaesthetise the greater and lesser palatine nerves near their foramina before extracting upper premolar and molar teeth. (Kenhub: Palatine bone.)

A cleft palate occurs when the palatal shelves fail to fuse in the midline during development. It affects roughly 1 in 1,000 births and can cause feeding difficulty, recurrent ear infections and speech problems. (TeachMeAnatomy: The Palate.)

The nearest named structures in the 3D model, measured from the centre of each part:

• Vomer · skeletal
• Tensor veli palatini · muscular
• Superior pharyngeal constrictor · muscular
• Inferior nasal concha · skeletal
• Internal carotid artery · cardiovascular
• Upper second secondary molar tooth · digestive
• Pterygomandibular raphe · muscular
• Sphenoid bone · skeletal
• Inferior rectus · muscular
• Inferior branch of oculomotor nerve · nervous