Metopism

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Metopism
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Baby skull and metopic (frontal) suture [1]

Metopism is the condition of having a persistent metopic suture, [2] or persistence of the frontal metopic suture in the adult human skull. [3] Metopism is the opposite of craniosynostosis. [4] The main factor of the metopic suture is to increase the volume of the anterior cranial fossa. The frontal bone includes the forehead, and the roofs of the orbits (bony sockets) of the eyes. The frontal bone has vertical portion (squama) and horizontal portion (orbital part). Some adults have a metopic or frontal suture in the vertical portion. [5] During the uterine period, there is a membranous tissue between the right and left halves of thr frontal bones of the fetus. On each half, a primary ossification center appears about the end of the second month of the fetus. The primary ossification center extends to form the corresponding half of the vertical part (squama) and horizontal part (orbital part) of the frontal bone.

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At birth the frontal bone contains two portions, separated by the metopic (frontal) suture. Metopism is the condition of having a persistent metopic suture. The metopic suture is typically obliterated, except at its lower part, by the eighth year, but infrequently persists throughout life. [6] There is no single proven cause of metopism. Its occurrence, when severe, can be associated with visional, learning, and behavioral problems. Some cases do not require any treatment, but surgical repair can be offered. Treatment teams include neurosurgeons, plastic surgeons, neurologists, oral and maxillofacial surgeons, audiologists, neuroscience nursing professionals, speech therapists, physical therapists, dentists, otolaryngologists, ophthalmologists, psychiatrists, psychologists and social workers. [7]

Infant frontal bones have two portions Fontanelle.png
Infant frontal bones have two portions

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<span class="mw-page-title-main">Frontal suture</span> Midline joint of the forehead

The frontal suture is a fibrous joint that divides the two halves of the frontal bone of the skull in infants and children. Typically, it completely fuses between three and nine months of age, with the two halves of the frontal bone being fused together. It is also called the metopic suture, although this term may also refer specifically to a persistent frontal suture.

<span class="mw-page-title-main">Coronal suture</span> Connective tissue on the skull

The coronal suture is a dense, fibrous connective tissue joint that separates the two parietal bones from the frontal bone of the skull.

<span class="mw-page-title-main">Squamous part of the frontal bone</span> Upper two-thirds of the forward skull

The squamous part of the frontal bone is the superior portion when viewed in standard anatomical orientation. There are two surfaces of the squamous part of the frontal bone: the external surface, and the internal surface.

<span class="mw-page-title-main">Zygomatic process</span> 3 projections from other skull bones which articulate with the zygomatic bone

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

<span class="mw-page-title-main">Calvaria (skull)</span> Top part of the skull

The calvaria is the top part of the skull. It is the superior part of the neurocranium and covers the cranial cavity containing the brain. It forms the main component of the skull roof.

<span class="mw-page-title-main">Neurocranium</span> Part of the skull around the brain

In human anatomy, the neurocranium, also known as the braincase, brainpan, or brain-pan, is the upper and back part of the skull, which forms a protective case around the brain. In the human skull, the neurocranium includes the calvaria or skullcap. The remainder of the skull is the facial skeleton.

References

  1. "Frontal Bone". InnerBody.
  2. "Metopism Medical Definition - Merriam-Webster Medical Dictionary". merriam-webster.com.
  3. "Metopism -- Medical Definition". medilexicon.com.
  4. Haidar Kabbani-Talkad S. Raghuveer. "Craniosynostosis". aafp.org.
  5. Aaron Wong. "Frontal bone". radiopaedia.org.
  6. "II. Osteology. 5a. 3. The Frontal Bone. Gray, Henry. 1918. Anatomy of the Human Body". bartleby.com.
  7. Boston Childrens Hospital 2013. "Metopic Synostosis (Trigonocephaly) - Boston Children's Hospital". childrenshospital.org.{{cite web}}: CS1 maint: numeric names: authors list (link)

Sources