Zygomatic process

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The Zygomatic process forms an "L" in this picture. Gray164.png
The Zygomatic process forms an "L" in this picture.
As a comparison, this is how the skull looks with almost all of the zygomatic process removed. Gray189.png
As a comparison, this is how the skull looks with almost all of the zygomatic process removed.

The zygomatic processes are three processes (protrusions) from other bones of the skull which each articulate with the zygomatic bone. The three processes are: [1]

Contents

The term zygomatic derives from the Greek Ζυγόμα, zygoma, meaning "yoke". The zygomatic process is occasionally referred to as the zygoma, but this term usually refers to the zygomatic bone or occasionally the zygomatic arch.

Zygomatic process of frontal bone

Zygomatic process of frontal bone
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Frontal bone at birth (Zygomatic process visible at lower right)
Details
Identifiers
Latin processus zygomaticus ossis frontalis
Anatomical terms of bone

The supraorbital margin of the frontal bone ends laterally in its zygomatic process, which is strong and prominent, and articulates with the zygomatic bone. The zygomatic process of the frontal bone extends from the frontal bone laterally and inferiorly.

Zygomatic process of maxilla

Zygomatic process of maxilla
Zygomatic process of maxilla - skull - anterior view.png
Zygomatic process shown in red
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Left zygomatic bone in situ (Zygomatic process of maxilla is shown in yellow.)
Details
Identifiers
Latin processus zygomaticus maxillae
Anatomical terms of bone

The zygomatic process of the maxilla [2] (malar process) is a rough triangular eminence, situated at the angle of separation of the anterior, zygomatic, and orbital surfaces.

Zygomatic process of temporal bone

Zygomatic process of temporal bone
Zygomatic process of temporal bone - lateral view.png
Zygomatic process shown in red
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Articulation of the mandible. Lateral aspect (Zygomatic process visible at center)
Details
Identifiers
Latin processus zygomaticus ossis temporalis
Anatomical terms of bone

The zygomatic process of the temporal bone is a long, arched process projecting from the lower part of the squamous portion of the temporal bone. It articulates with the zygomatic bone.

This process is at first directed lateralward, its two surfaces looking upward and downward; it then appears as if twisted inward upon itself, and runs forward, its surfaces now looking medialward and lateralward.

The superior border is long, thin, and sharp, and serves for the attachment of the temporal fascia.

The inferior border, short, thick, and arched, has attached to it some fibers of the masseter.

The lateral surface is convex and subcutaneous. The medial surface is concave, and affords attachment to the masseter.

The anterior end is deeply serrated and articulates with the zygomatic bone. The posterior end is connected to the squama by two roots, the anterior and posterior roots:

Processes of the zygomatic bone

The zygomatic bone itself has four processes, namely the frontosphenoidal, orbital, maxillary and temporal processes.

The frontosphenoidal process is thick and serrated. The cranial suture between the frontal and zygomatic bone is found here. On its orbital surface, just within the orbital margin and about 11 mm below the zygomaticofrontal suture is a tubercle of varying size and form, but present in 95 per cent of skulls (Whitnall 43). This tubercle is not seen in the picture.

The orbital process is a thick, strong plate, projecting backward and medialward from the orbital margin. It is the gloomy area beneath the lac(rimal) and ethmoidal bones in the image.

The maxillary process presents a rough, triangular surface which articulates with the maxilla. It is the area below "zygomatic" in the image.

The temporal process, long, narrow, and serrated, articulates with the zygomatic process of the temporal. It is the process to the right of "zygomatic" in the image.

Additional images

See also

Related Research Articles

Maxilla

The maxilla in vertebrates is the upper fixed bone of the jaw formed from the fusion of two maxillary bones. In humans, the upper jaw includes the hard palate in the front of the mouth. The two maxillary bones are fused at the intermaxillary suture, forming the anterior nasal spine. This is similar to the mandible, which is also a fusion of two mandibular bones at the mandibular symphysis. The mandible is the movable part of the jaw.

Zygomatic bone Facial bone

In the human skull, the zygomatic bone is a paired irregular bone which articulates with the maxilla, the temporal bone, the sphenoid bone and the frontal bone. It is situated at the upper and lateral part of the face and forms the prominence of the cheek, part of the lateral wall and floor of the orbit, and parts of the temporal fossa and the infratemporal fossa. It presents a malar and a temporal surface; four processes, and four borders.

Sphenoid bone Unpaired bone situated at the front middle of the skull in front of the temporal bone and basilar part of the occipital bone

The sphenoid bone is an unpaired bone of the neurocranium. It is situated in the middle of the skull towards the front, in front of the basilar part of the occipital bone. The sphenoid bone is one of the seven bones that articulate to form the orbit. Its shape somewhat resembles that of a butterfly or bat with its wings extended.

Frontal bone Bone in the human skull

The frontal bone is a bone in the human skull. The bone consists of two portions. These are the vertically oriented squamous part, and the horizontally oriented orbital part, making up the bony part of the forehead, part of the bony orbital cavity holding the eye, and part of the bony part of the nose respectively. The name comes from the Latin word frons.

Inferior nasal concha

The inferior nasal concha is one of the three paired nasal conchae in the nose. It extends horizontally along the lateral wall of the nasal cavity and consists of a lamina of spongy bone, curled upon itself like a scroll,. The inferior nasal conchae are considered a pair of facial bones. As the air passes through the turbinates, the air is churned against these mucosa-lined bones in order to receive warmth, moisture and cleansing. Superior to inferior nasal concha are the middle nasal concha and superior nasal concha which arise from the cranial portion of the skull. Hence, these two are considered as a part of the cranial bones.

Zygomatic arch Cheek bone

In anatomy, the zygomatic arch, or cheek bone, is a part of the skull formed by the zygomatic process of the temporal bone and the temporal process of the zygomatic bone, the two being united by an oblique suture ; the tendon of the temporal muscle passes medial to the arch, to gain insertion into the coronoid process of the mandible (jawbone).

Orbit (anatomy) Cavity or socket of the skull in which the eye and its appendages are situated

In anatomy, the orbit is the cavity or socket of the skull in which the eye and its appendages are situated. "Orbit" can refer to the bony socket, or it can also be used to imply the contents. In the adult human, the volume of the orbit is 30 millilitres, of which the eye occupies 6.5 ml. The orbital contents comprise the eye, the orbital and retrobulbar fascia, extraocular muscles, cranial nerves II, III, IV, V, and VI, blood vessels, fat, the lacrimal gland with its sac and duct, the eyelids, medial and lateral palpebral ligaments, check ligaments, the suspensory ligament, septum, ciliary ganglion and short ciliary nerves.

Process (anatomy)

In anatomy, a process is a projection or outgrowth of tissue from a larger body. For instance, in a vertebra, a process may serve for muscle attachment and leverage, or to fit, with another vertebra. The word is used even at the microanatomic level, where cells can have processes such as cilia or pedicels. Depending on the tissue, processes may also be called by other terms, such as apophysis, tubercle, or protuberance.

Temporal fossa

The temporal fossa is a fossa on the side of the skull bounded by the temporal lines and terminating below the level of the zygomatic arch.

Condyloid process

The condyloid process or condylar process is the process on the human mandible and some other species' mandibles that ends in a condyle, the mandibular condyle. It is thicker than the coronoid process of the mandible and consists of two portions: the condyle and the constricted portion which supports it, the neck.

Pterygoid processes of the sphenoid

The pterygoid processes of the sphenoid, one on either side, descend perpendicularly from the regions where the body and the greater wings of the sphenoid bone unite.

Greater wing of sphenoid bone

The greater wing of the sphenoid bone, or alisphenoid, is a bony process of the sphenoid bone; there is one on each side, extending from the side of the body of the sphenoid and curving upward, laterally, and backward.

Squamous part of temporal bone

The squamous part of temporal bone, or temporal squama, forms the front and upper part of the temporal bone, and is scale-like, thin, and translucent.

Lateral parts of occipital bone

The lateral parts of the occipital bone are situated at the sides of the foramen magnum; on their under surfaces are the condyles for articulation with the superior facets of the atlas.

Squamous part of the frontal bone

There are two surfaces of the squamous part of the frontal bone: the external surface, and the internal surface.

Infratemporal fossa

The infratemporal fossa is an irregularly shaped cavity, situated below and medial to the zygomatic arch. It is not fully enclosed by bone in all directions, and it contains superficial muscles that are visible during dissection after removing skin and fascia: namely, the lower part of the temporalis muscle, the lateral pterygoid, and the medial pterygoid.

Sphenoidal process of palatine bone

The sphenoidal process of the palatine bone is a thin, compressed plate, much smaller than the orbital, and directed upward and medialward.

Orbital process of palatine bone

The orbital process of the palatine bone is placed on a higher level than the sphenoidal, and is directed upward and lateralward from the front of the vertical part, to which it is connected by a constricted neck. It presents five surfaces, which enclose an air cell. Of these surfaces, three are articular and two non-articular.

Frontal process of maxilla

The frontal process of maxilla is a strong plate, which projects upward, medialward, and backward from the maxilla, forming part of the lateral boundary of the nose.

The pterygo-maxillary or zygomatic Fossa is an irregularly shaped cavity, situated below and on the inner side of the zygoma; bounded, in front, by the zygomatic surface of the superior maxillary bone and the ridge which descends from its malar process; behind, by the posterior border of the external pterygoid plate and the eminentia articularis; above, by the pterygoid ridge on the outer surface of the great wing of the sphenoid, and the under part of the squamous portion of the temporal; below by the alveolar border of the superior maxilla; internally, by the external pterygoid plate; and externally, by the zygomatic arch ramus of the lower jaw. It contains the lower part of the temporal, the external and internal pterygoid muscles, the internal maxillary artery and vein, and inferior maxillary nerve and their branches. At its upper and inner part may be observed two fissures, the spheno-maxillary and pterygo-maxillary.

References

  1. Marieb & Hoehn's (2010) Human Anatomy & Physiology
  2. Google Books: zygomatic process of the maxilla: Exercises in Oral Radiology and Interpretation – E-Book (Elsevier Health Sciences, Dec 12, 2003, by Robert P. Langlais) – Retrieved 2018-08-26

This article incorporates text in the public domain from the 20th edition of Gray's Anatomy (1918)