Zygomatic process

Zygomatic process
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Zygomatic process Definition

It is a slender protrusion of the temporal bone that serves to strengthen the Zygomatic arch.

Zygomatic process Etymology

Picture of Zygomatic process

Picture 1 – Zygomatic process

The word “Zygomatic” comes from the Greek term “Zygon” which means “Yoke” due to its similarity with a yoke set on oxen. The term “process” comes from the fusion of two Latin words “pro” standing for “forward” and “cessus” for gone. It is an archaic word that may be traced back to the compositions of Celsus, an early anatomist.

Zygomatic process Names

This outgrowth is known by various other names like:

  • Processus zygomaticus
  • Temporal zygomatic process
  • Processus zygomaticus ossis temporalis

In Latin, it is known as “Processus zygomaticus ossis temporalis”.

Zygomatic process Description

This is a thin, arch-shaped protrusion that arises from two roots on the anterolateral face of the squamous temporal bone. The anterior end of the arch arises in a media position from the articular tubercle. Its posterior root develops above the external acoustic meatus as a ridge. Its anterior root originates medially from the articular tubercle. The posterior root extends as the superior and the anterior root proceeds as the inferior margin of the protrusion.

The anterior root of the bony outgrowth makes a rough, toothed suture that joins the zygomatic bone. The temporalis fascia gets its site of attachment at the superior border of the protrusion. The inferior border and medial surface provide adhesion for the masseter muscle.

The zygomatic bone, in many cases, does not lead to the development of the inferior orbital fissure. This may be due to:

  • Articulation of the greater sphenoid wing with the maxilla
  • Interference of a wormian bone

The maxilla may be straightaway attached to the zygomatic temporal bone process by a dorsal extension of the maxillary zygomatic process. The maxillary process may unite with the lacrimal hamulus.

Zygomatic process Function

It serves to strengthen the zygomatic arch.

Zygomatic Process of Maxilla

It is a rough, pyramidal protuberance that laterally projects to create with the zygomatic bone a non-smooth articular surface. It has three surfaces – facial, orbital and infratemporal. Its apex is medial and base lateral. It is referred to as “Processus zygomaticus maxillae” in Latin language.

It forms an anterior surface section in the front. It is concave at the back and forms a section of the infratemporal fossa. It is rough at the top and jagged, which helps it articulate with the zygomatic bone. At the bottom, it exhibits the prominent arched border. This acts as a division between the infratemporal and anterior surfaces.

Zygomatic Process of Frontal Bone

It is the zygomatic process section that comprises of the frontal bone. It extends in a lateral and inferior manner from the frontal bone. It is a thick lateral outgrowth of the supra-orbital margin. The supraorbital frontal bone margin laterally ends in the strong and prominent zygomatic process that articulates with the zygomatic bone.

Fracture of Zygomatic process of temporal bone

Depressed fractures of distal zygomatic process section of temporal bone typically cause malocclusion, difficulties in eating and atrophy of masticatory muscles. In the early stages, however, such fractures cause little or no symptoms. As a result, these often go undiagnosed. With passing time, osseous callus develops and leads to reduced movement of the jaw. Diagnosis can help identify clinical signs like:

  • Atrophy of masticatory muscles
  • Decreased movement of the jaw
  • Malocclusion
  • Perceptible hard inflammation in TMJ area

The differential diagnosis aims at distinguishing the fracture from other similar problems like:

  • Canine masticatory myopathy
  • Degenerative joint disease (DJD) of TMJ
  • Infection of TMJ
  • Mandibular neuropraxia
  • Neoplasia of TMJ
  • TMJ (Temporomandibular joint) fracture

The problem can be treated by surgical excision of caudodistal zygomatic process. It generally has a good prognosis.

Zygomatic process Pictures

Here are some useful Zygomatic process photos that will help you get an exact idea about the physical appearance of this bony projection. You may use these Zygomatic process images for your reference.

Image of Zygomatic process

Picture 2 – Zygomatic process Image

Photo of Zygomatic process

Picture 3 – Zygomatic process Photo

References:

http://www.anatomyexpert.com/structure_detail/590/901/

http://www.vetstream.com/canis/Content/Disease/dis00902

http://www.geemboomba.com/home/radiology/radiographic-landmarks-in-regular-radiographs/zygomatic-process

http://www.enotes.com/topic/Zygomatic_process_of_maxilla

 

 

Last modified on September 1st, 2017 at 8:22 am

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