The maxillary bones are a pair of large bones that fuse together at the midline of the face to form the upper jaw. These bones are central to the structure of the human face. They play a role in supporting various facial features and housing the upper teeth. The maxillae contribute to the architecture of the face, defining its overall shape and providing attachment points for many muscles involved in facial expressions, chewing, and speaking.
The Eye Sockets
The maxillary bones contribute to the formation of the eye sockets, also known as the orbits. The orbital surface of the maxilla forms a significant portion of the floor of the orbit, separating the eye from the underlying maxillary sinus. This part of the maxilla provides support for the eyeballs and the soft tissues within the orbital cavity. Along with other bones like the zygomatic and palatine bones, the maxilla helps create the pyramidal structure of the eye socket.
The maxilla’s frontal process also forms part of the medial margin of the orbit, contributing to the framework that protects the eye. Within the orbital surface, a shallow channel, the infraorbital groove, transitions into a canal. This canal transmits the infraorbital nerve and vessels, which exit the skull through the infraorbital foramen, located just below the orbital rim. The maxilla provides structural integrity and pathways for neurovascular structures to the eye region.
The Nasal Passages
The maxillary bones contribute to the nasal cavity, forming its floor and parts of its lateral walls. The palatine process of the maxilla, a thick horizontal projection, forms a significant portion of the floor of the nasal cavity. This creates the defined space through which air passes during breathing. The maxilla also forms the inferior and lateral margins of the pyriform aperture, which is the anterior opening into the nasal cavity.
The medial wall of the maxillary sinus also forms part of the lateral nasal wall. This arrangement provides structural support for the nasal passages. It facilitates breathing and olfaction, ensuring proper air flow and smell reception.
The Roof of the Mouth
The maxillary bones contribute to the oral cavity by forming the hard palate, which is the bony roof of the mouth. The palatine process of the maxilla forms the majority of the hard palate. This structure separates the oral cavity from the nasal cavities, a separation that is important for both eating and speech.
The hard palate provides a rigid surface against which the tongue can press, important for manipulating food during chewing and articulating speech sounds. Additionally, the maxilla contains the alveolar processes, extensions that house the upper teeth. These processes contain the sockets where tooth roots are embedded, providing stability and support for mastication. The hard palate, with its integrated dental support, is an important component of the oral system.
The Maxillary Sinuses
The maxillary sinuses are large, air-filled cavities located within the maxillary bones. These are the largest of the paranasal sinuses, which are a group of air-filled spaces surrounding the nasal cavity. The maxillary sinuses are pyramidal in shape, with their base adjacent to the nasal cavity and the apex pointing towards the cheekbone.
These sinuses serve several functions, including lightening the weight of the skull and contributing to the resonance of sound. They also warm and humidify inhaled air before it reaches the lungs. The floor of the maxillary sinus is formed by the alveolar process of the maxilla, and in some individuals, the roots of the upper molar teeth can project into the sinus space.