The palatine bones are a pair of small, irregularly shaped bones located deep within the skull. They form a significant portion of the facial skeleton, situated in the posterior region of the nasal and oral cavities. Each palatine bone is characteristically L-shaped, contributing to bony structures that separate the mouth from the nasal passages. They are considered part of the viscerocranium, the bones forming the face.
Anatomical Placement
The palatine bones are positioned at the back of the nasal cavity, wedged between the maxilla and the sphenoid bone. They form the posterior one-third of the hard palate, which is the bony roof of the mouth and the floor of the nasal cavity. Their location is central to the midface, contributing to the walls of the nasal cavity, the mouth’s roof, and the floor of the orbits.
Each palatine bone articulates with six other bones within the skull. Anteriorly, it connects with the maxilla, forming the transverse palatine suture. Superiorly, it makes contact with the sphenoid and ethmoid bones. It also articulates with the inferior nasal concha and the vomer. The two palatine bones meet at the midline to form the median palatine suture.
Structure and Composition
The L-shape of the palatine bone is created by the junction of two main components: the horizontal plate and the perpendicular plate. The horizontal plate is a flat, rectangular section that projects medially, meeting the maxilla anteriorly and its counterpart at the midline. This section forms the posterior part of the hard palate and the floor of the nasal cavity.
The perpendicular plate extends upward from the horizontal plate, contributing to the lateral wall of the nasal cavity. Projecting from this L-shaped structure are three distinct processes. The pyramidal process projects posterolaterally from the junction of the two plates, filling the space between the pterygoid processes of the sphenoid bone.
The orbital and sphenoidal processes rise from the superior aspect of the perpendicular plate. These two processes are separated by the sphenopalatine notch, a deep indentation. This notch becomes the sphenopalatine foramen when the bone articulates with the sphenoid. The orbital process helps form a small part of the floor of the orbit.
Role in Facial Function
The palatine bone’s central location and complex structure allow it to serve several functions. Its primary contribution is forming the hard palate, which creates a solid partition between the oral and nasal cavities. This separation is necessary for effective breathing while chewing and swallowing food.
The bone provides structural support for the surrounding facial framework. It contributes to the formation of the pterygopalatine fossa, a deep space that houses nerves and blood vessels traveling to the nose, orbit, and palate. Openings within the bone, such as the greater and lesser palatine foramina, transmit nerves and blood vessels to the soft palate and gums.
The bone also provides attachment points for various muscles. These muscles are involved in the movement of the soft palate, which is important for speech articulation and the process of swallowing.