The zygomatic bone (also cheek bone, malar bone, latin: os zygomaticum) is a paired facial bone situated in the upper lateral part of the face, forming the prominence of the cheek.
The zygomatic bone also takes part in forming the floor of the orbit, as well as the temporal fossa and the infratemporal fossa. The zygomatic bone articulates with four bones: the maxilla, the temporal bone, the sphenoid, and the frontal bone.
Each zygomatic bone has three surfaces (orbital, temporal, lateral), four borders (orbital or antero-superior, maxillary or antero-inferior, temporal or postero-superior, zygomatic or postero-inferior), two processes (frontal, temporal). The bone houses the zygomatic canal.
Surfaces of zygomatic bone
The orbital surface of the zygomatic bone forms part of the lateral side of the orbital floor. The orbital surface presents an opening, the zygomatico-orbital foramen.
The zygomatico-orbital foramen is an opening on the medial aspect of the frontal process of the zygomatic bone. It continues as the zygomatic canal leading to both zygomaticotemporal and zygomaticofacial foramina.
The temporal surface of the zygomatic bone is directed posteriorly and medially, is concave and presents medially a surface for articulation with the zygomatic process of the maxilla, and laterally a concave surface that forms the anterior border of the infratemporal fossa. Near the center of this surface is the zygomaticotemporal foramen.
Zygomaticotemporal foramen is an opening on the temporal surface of the zygomatic bone near the base of the frontal process. It leads into the zygomatic canal and is a passage for the zygomaticotemporal nerve.
The lateral surface of the zygomatic bone participates in forming part of the infra-orbital margin, and is perforated by zygomaticofacial foramen near its center.
The zygomaticofacial foramen is one or two openings on the facial surface of the zygomatic bone near its orbital border, it can sometimes be absent. This opening leads into the zygomatic nerve and is a passage for the zygomatic nerve and zygomatic blood vessels.
The infra-orbital margin is the lower margin of the orbit formed partly by the maxilla, and partly by the zygomatic bone.
Processes of zygomatic bone
The frontal process of the zygomatic bone is a process which unites the zygomatic bone with the zygomatic process of the frontal bone.
The temporal process of the zygomatic bone is a posteriorly directed process which unites the zygomatic bone with the zygomatic process of the temporal bone to form the zygomatic arch.
The zygomatic canal is a passage within the zygomatic bone starting with one opening on the orbital surface (zygomatico-orbital foramen), and leading to openings on the temporal (zygomaticotemporal foramen) and the facial surfaces (zygomaticofacial foramen) of the zygomatic bone. The zygomatic nerve dividing into branches and the zygomatic blood vessels pass through it.