Orbital process of the zygomatic bone
Encyclopedia
The orbital process of the zygomatic bone
is a thick, strong plate, projecting backward and medialward from the orbital margin.
Its antero-medial surface forms, by its junction with the orbital surface of the maxilla
and with the great wing of the sphenoid
, part of the floor and lateral wall of the orbit.
On it are seen the orifices of two canals, the zygomatico-orbital foramina; one of these canals opens into the temporal fossa
, the other on the malar surface of the bone; the former transmits the zygomaticotemporal, the latter the zygomaticofacial nerve
.
At the angle of junction of the sphenoidal and maxillary portions, a short, concave, non-articular part is generally seen; this forms the anterior boundary of the inferior orbital fissure: occasionally, this non-articular part is absent, the fissure then being completed by the junction of the maxilla and sphenoid, or by the interposition of a small sutural bone in the angular interval between them.
Zygomatic bone
The zygomatic bone is a paired bone of the human skull. It articulates with the maxilla, the temporal bone, the sphenoid bone and the frontal bone. The zygomatic is homologous to the jugal bone of other tetrapods...
is a thick, strong plate, projecting backward and medialward from the orbital margin.
Its antero-medial surface forms, by its junction with the orbital surface of the maxilla
Maxilla
The maxilla is a fusion of two bones along the palatal fissure that form the upper jaw. This is similar to the mandible , which is also a fusion of two halves at the mental symphysis. Sometimes The maxilla (plural: maxillae) is a fusion of two bones along the palatal fissure that form the upper...
and with the great wing of the sphenoid
Sphenoid bone
The sphenoid bone is an unpaired bone situated at the base of the skull in front of the temporal bone and basilar part of the occipital bone.The sphenoid bone is one of the seven bones that articulate to form the orbit...
, part of the floor and lateral wall of the orbit.
On it are seen the orifices of two canals, the zygomatico-orbital foramina; one of these canals opens into the temporal fossa
Temporal fossa
The temporal fossa is a shallow depression on the side of the skull bounded by the temporal lines and terminating below the level of the zygomatic arch.-Boundaries:...
, the other on the malar surface of the bone; the former transmits the zygomaticotemporal, the latter the zygomaticofacial nerve
Zygomaticofacial nerve
The zygomaticofacial nerve or zygomaticofacial branch of zygomatic nerve passes along the infero-lateral angle of the orbit, emerges upon the face through the zygomaticofacial foramen in the zygomatic bone, and, perforating the Orbicularis oculi to reach the skin of the malar area.It joins with...
.
- Its postero-lateral surface, smooth and convex, forms parts of the temporal and infratemporal fossae.
- Its anterior margin, smooth and rounded, is part of the circumference of the orbit.
- Its superior margin, rough, and directed horizontally, articulates with the frontal bone behind the zygomatic process.
- Its posterior margin is serrated for articulation, with the great wing of the sphenoid and the orbital surface of the maxilla.
At the angle of junction of the sphenoidal and maxillary portions, a short, concave, non-articular part is generally seen; this forms the anterior boundary of the inferior orbital fissure: occasionally, this non-articular part is absent, the fissure then being completed by the junction of the maxilla and sphenoid, or by the interposition of a small sutural bone in the angular interval between them.