Upper jaw (body of maxilla)
The body is the central and largest portion of the maxilla. It gives support to all four processes and houses the most prominent paranasal sinus - the maxillary sinus (Read more!).
Anatomical landmarks
Both maxillae fuse in the midline to form the upper jaw. The fusion of both bones creates a sharp, thin midline projection called the anterior nasal spine. It is found in the midline at the inferior margin of the nasal aperture, and it is the anterior point of the upper jaw that serves as a cephalometric landmark.
The maxillary body has the following four surfaces:
- Orbital surface - triangular-shaped superior surface that forms most of the orbital floor; it articulates with the lacrimal bone, ethmoid, palatine and zygomatic bones; it also participates in the formation of the inferior orbital fissure;
- Infraorbital groove - narrow sulcus that is found on the mid-posterior half of the orbital floor; it leads into a tunnel called the infraorbital canal, which opens on the anterior surface of the body via the infraorbital foramen; it transmits the infraorbital nerve and vessels;
- Maxillary part of orbital margin - found anterior to the orbital surface; it contributes to the inferior margin of the orbit;
- Nasal surface - medial surface of the body that forms a part of the lateral wall of the nasal cavity and the medial wall of the maxillary sinus;
- Lacrimal groove - a deep and relatively wide vertical groove that is found anterior to the maxillary hiatus and posterior to the anterior lacrimal crest; it participates in the formation of the nasolacrimal canal and lodges the nasolacrimal duct;
- Lacrimal margin - border of the nasal surface that articulates with the lacrimal bone;
- Maxillary hiatus - large and irregular-shaped opening to the maxillary sinus;
- Conchal crest - a somewhat horizontally-oriented ridge that articulates with the inferior nasal concha; it is found in the lower anterior aspect of this surface;
- Infratemporal surface - posterolaterally directed surface that forms the anterior wall of the infratemporal fossa;
- Maxillary tuberosity - round bony eminence that is found on the inferior aspect of this surface;
- Alveolar foramina - several small openings that are found more or less in the middle aspect of this surface; they lead into the alveolar canals, which transmit the alveolar nerves and vessels;
- Anterior surface - concave anterolaterally-oriented facial surface;
- Nasal notch - deep concavity that participates in the formation of the piriform aperture; both nasal notches are separated by the anterior nasal spine;
- Infraorbital foramen - opening that is found below the middle part of the infraorbital margin; it transmits the infraorbital nerve and vessels;
- Canine fossa - a slightly concave depression of variable extent; it is found just inferior to the infraorbital foramen.
The greater palatine groove is found posteriorly at the region where the nasal surface connects with the infratemporal surface. It is an oblique sulcus that transmits the greater palatine nerve and vessels.