The palatine bone is a paired structure of the facial skeleton, positioned deep within the skull near the nasal and oral cavities. It is an irregular bone that contributes to several facial structures. The palatine bone forms a specific portion of the hard palate, which is the bony roof of the mouth and the floor of the nasal cavity. This complex bone separates the upper airway from the digestive tract.
The Exact Number and General Placement
There are two palatine bones in the human skull. These two bones are mirror images of each other, joining together in the midline of the face. They are situated in a relatively concealed position, located at the back of the nasal cavity and behind the upper jaw bone (maxilla).
The palatine bones form the posterior section of the hard palate, contributing approximately the rear one-third of the roof of the mouth. This placement means they are positioned between the maxilla in front and the sphenoid bone further back in the skull. In addition to the palate, the two bones also form part of the lateral walls of the nasal cavity.
Anatomy and Structure
Each palatine bone has a distinct and complex shape, often described as resembling the letter “L” when viewed from the side. This shape is created by two primary components that meet at nearly a right angle: a horizontal plate and a perpendicular plate. The horizontal plate extends inward and meets its counterpart to form the posterior part of the hard palate.
The perpendicular plate extends upward from the horizontal plate, contributing to the side wall of the nasal cavity. This perpendicular portion connects with several neighboring bones, acting as a bridge in the facial structure. The palatine bone articulates with six other bones: the maxilla, sphenoid, ethmoid, vomer, inferior nasal concha, and the opposite palatine bone.
Essential Roles in Facial Structure
The primary function of the palatine bones is constructing the hard palate, which serves as a firm separation between the oral cavity below and the nasal cavity above. This bony barrier allows a person to breathe through the nose while simultaneously chewing food in the mouth.
Beyond the palate, the palatine bone also contributes to the floor of the eye orbit. The bone also contains important passageways for the nervous and vascular systems. Specifically, the greater and lesser palatine foramina are openings within the bone that allow nerves and blood vessels to pass through.
The greater palatine foramen transmits the greater palatine nerve and blood vessels to the hard palate and gums. The smaller lesser palatine foramina allow the lesser palatine nerves and vessels to supply the soft palate and the tonsil area. These openings are necessary for sensation and blood supply to the tissues of the mouth and throat.