anatomy Anatomy () is the branch of morphology concerned with the study of the internal structure of organisms and their parts. Anatomy is a branch of natural science that deals with the structural organization of living things. It is an old scien ...

, the zygomatic arch (colloquially known as the cheek bone), is a part of the

skull The skull, or cranium, is typically a bony enclosure around the brain of a vertebrate. In some fish, and amphibians, the skull is of cartilage. The skull is at the head end of the vertebrate. In the human, the skull comprises two prominent ...

formed by the

zygomatic process The zygomatic processes (aka. malar) are three processes (protrusions) from other bones of the skull which each articulate with the zygomatic bone. The three processes are: * Zygomatic process of frontal bone from the frontal bone * Zygomatic ...

of the

temporal bone The temporal bone is a paired bone situated at the sides and base of the skull, lateral to the temporal lobe of the cerebral cortex. The temporal bones are overlaid by the sides of the head known as the temples where four of the cranial bone ...

(a bone extending forward from the side of the skull, over the opening of the ear) and the temporal

process A process is a series or set of activities that interact to produce a result; it may occur once-only or be recurrent or periodic. Things called a process include: Business and management * Business process, activities that produce a specific s ...

of the

zygomatic bone In the human skull, the zygomatic bone (from ), also called cheekbone or malar bone, is a paired irregular bone, situated at the upper and lateral part of the face and forming part of the lateral wall and floor of the orbit, of the temporal fos ...

(the side of the cheekbone), the two being united by an oblique suture (the zygomaticotemporal suture); the

tendon A tendon or sinew is a tough band of fibrous connective tissue, dense fibrous connective tissue that connects skeletal muscle, muscle to bone. It sends the mechanical forces of muscle contraction to the skeletal system, while withstanding tensi ...

of the temporal muscle passes medial to (i.e. through the middle of) the arch, to gain insertion into the

coronoid process of the mandible In human anatomy, the mandible's coronoid process () is a thin, triangular eminence, which is flattened from side to side and varies in shape and size. Its anterior border is convex and is continuous below with the anterior border of the ramus. ...

(jawbone). The jugal point is the point at the anterior (towards face) end of the upper border of the zygomatic arch where the masseteric and maxillary edges meet at an angle, and where it meets the process of the zygomatic bone. The arch is typical of ''

Synapsida Synapsida is a diverse group of tetrapod vertebrates that includes all mammals and their extinct relatives. It is one of the two major clades of the group Amniota, the other being the more diverse group Sauropsida (which includes all extant rep ...

'' ("fused arch"), a

clade In biology, a clade (), also known as a Monophyly, monophyletic group or natural group, is a group of organisms that is composed of a common ancestor and all of its descendants. Clades are the fundamental unit of cladistics, a modern approach t ...

amniote Amniotes are tetrapod vertebrate animals belonging to the clade Amniota, a large group that comprises the vast majority of living terrestrial animal, terrestrial and semiaquatic vertebrates. Amniotes evolution, evolved from amphibious Stem tet ...

s that includes

mammal A mammal () is a vertebrate animal of the Class (biology), class Mammalia (). Mammals are characterised by the presence of milk-producing mammary glands for feeding their young, a broad neocortex region of the brain, fur or hair, and three ...

s and their extinct relatives, such as ''

Moschops ''Moschops'' (Greek for "calf face") is an extinct genus of therapsids that lived in the Guadalupian Epoch (geology), epoch, around 265–260 million years ago. They were heavily built plant eaters, and they may have lived partly in water, as hi ...

'' and ''

Dimetrodon ''Dimetrodon'' ( or ; ) is an extinct genus of sphenacodontid synapsid that lived during the Cisuralian (Early Permian) Epoch (geology), epoch of the Permian period, around 295–272 million years ago. With most species measuring long and ...

''. While the terms zygomatic arch and cheekbone are often used interchangeably, the arch is a specific anatomical structure within the

cheekbone In the human skull, the zygomatic bone (from ), also called cheekbone or malar bone, is a paired irregular bone, situated at the upper and lateral part of the face and forming part of the lateral wall and floor of the orbit (anatomy), orbit, of t ...

(zygomatic bone).

Structure

The zygomatic process of the temporal arises by two roots: * an ''anterior'', directed inward in front of the mandibular fossa, where it expands to form the articular tubercle. * a ''posterior'', which runs backward above the

external acoustic meatus The ear canal (external acoustic meatus, external auditory meatus, EAM) is a pathway running from the outer ear to the middle ear. The adult human ear canal extends from the auricle to the eardrum and is about in length and in diameter. Str ...

and is continuous with the supramastoid crest. The upper border of the arch gives attachment to the

temporal fascia The temporal fascia (or deep temporal fascia) is a fascia of the head that covers the temporalis muscle and structures situated superior to the zygomatic arch. The fascia is attached superiorly at the superior temporal line; inferiorly, it split ...

; the lower border and medial surface give origin to the

masseter In anatomy, the masseter is one of the muscles of mastication. Found only in mammals, it is particularly powerful in herbivores to facilitate chewing of plant matter. The most obvious muscle of mastication is the masseter muscle, since it is the ...

Society and culture

High cheekbones are pronounced zygomatic arches, causing the upper part of the cheeks to jut out and form a line cut into the sides of the face. High cheekbones, forming a symmetrical face shape, are very common in fashion models and may be considered a beauty trait in both males and females within Eurocentric beauty standards.

Etymology

The term ''zygomatic'' derives from the Greek ζύγωμα zygōma, meaning "bolt, bar", derived from ζυγο-, "yoke, join". The Greek word was already used with this anatomical sense by

Galen Aelius Galenus or Claudius Galenus (; September 129 – AD), often Anglicization, anglicized as Galen () or Galen of Pergamon, was a Ancient Rome, Roman and Greeks, Greek physician, surgeon, and Philosophy, philosopher. Considered to be one o ...

(2.437, 746) in the 2nd century AD. The zygomatic arch is occasionally referred to as the

zygoma The term zygoma generally refers to the zygomatic bone, a bone of the human skull that is commonly referred to as the cheekbone or malar bone, but it may also refer to: * The zygomatic arch, a structure in the human skull formed primarily by parts ...

, but this term usually refers to the zygomatic bone or occasionally the

Other animals

The zygomatic arch is significant in

evolutionary biology Evolutionary biology is the subfield of biology that studies the evolutionary processes such as natural selection, common descent, and speciation that produced the diversity of life on Earth. In the 1930s, the discipline of evolutionary biolo ...

, as it is part of the structures derived from the ancestral single

temporal fenestra Temporal fenestrae are openings in the temporal region of the skull of some amniotes, behind the orbit (eye socket). These openings have historically been used to track the evolution and affinities of reptiles. Temporal fenestrae are commonly (al ...

of the

synapsid Synapsida is a diverse group of tetrapod vertebrates that includes all mammals and their extinct relatives. It is one of the two major clades of the group Amniota, the other being the more diverse group Sauropsida (which includes all extant rept ...

ancestor of

Additional images

File:Gray137.png, Left temporal bone, outer surface File:Gray165.png, Left zygomatic bone, malar surface File:Gray187.png, Base of skull, inferior surface File:Gray382.png, The temporalis; the zygomatic arch and masseter have been removed. File:Gray1024.png, Dissection, showing salivary glands of right side File:Sygomafracture.png, Fracture of the zygomatic arch as seen on plain X-ray File:Slide6JAN.JPG, Zygomatic arch, base of skull

References

External links

* () * {{Authority control Skull

Structure

Society and culture

Etymology

Other animals

Additional images

See also

References

External links