Maxilla

Maxillary sinus is an air space coverd by mucosal epithelium. It is the biggest sinus, which has a wide opening on the medial wall called the maxillary hiatus (hiatus maxillaris)which is enveloped by the:

• Inferior nasal concha and uncinate process which covers from the inferior side
• Ethmoid bulla which covers from the superior side
• Palatine bone which covers from the posterior side.

The maxillary sinus communicates with the nasal cavity by the semilunar hiatus (hiatus semilunaris).

Anterior surface (facies anterior) has the:

• Canine fossa (fossa canina) which lies above and lateral to the canine tooth. It is the depression in the anterior wall of the maxilla. The anterior superior alveolar vessels and nerves run between the fossa and maxillary sinus in the bony wall.
• Infraorbital margin (margo infraorbitalis).
• Infraorbital foramen (foramen infraorbitale) through which the infraorbital nerve and vessels leave the orbit.
• Nasal notch (incisura nasalis) with the anterior nasal spine (spina nasalis anterior).

nfratemporal surface (facies infratemporalis) has the:

• Maxillary tuberosity (tuber maxillae) with the:
• Alveolar foramina (foramina alveolares) which continue as:
• Alveolar canals (canales alveolares) which transmit nerves and vessels that pass through the thick maxillary wall.

Nasal surface (facies nasalis) has the:

• Conchal crest (crista conchalis) which is seen on palatine process as well.
• Lacrimal groove (sulcus lacrimalis) which empties into the nasolacrimal canal (canalis nasolacrimalis) which is found on the lacrimal bone and serves as the communication site between the orbit and the nasal cavity.

Orbital surface (facies orbitalis) is triangular. It has the infraorbital groove (sulcus infraorbitalis) which originates near the posterior border of the orbital surface and is converted anteriorly into the infraorbital canal (canalis infraorbitalis)which opens into the anterior surface of the maxilla.