What bones meet at the pterion

Pterion | Radiology Reference Article | mephistolessiveur.info

what bones meet at the pterion

Introduction: The frontal and the parietal bones superiorly and the greater inferiorly of one side meet at an H-shaped sutural junction termed the pterion. Keywords: Epipteric bones, Pterion, Pterion ossicle, Pterion types. Results: In the present study all types of pterion are observed. contact; stellate, all the four bones meet at a point; and epipteric, when there is. The pterion is the region where the frontal, parietal, temporal, and sphenoid bones join together. It is located on the side of the skull, just behind the temple.

what bones meet at the pterion

Indian J Otol ; As the bones are growing, the unossified sutural membranes intervene between their apposed margins. These sutural membranes connect the periosteum covering the outer and inner surfaces of the bone, which helps in growth as well as binding the bones together at their apposed margins. A study reveals that there are four types of pteria: These wormian bones are also called ossa wormiana, intersutural bones or Inca bones.

Studies reveal that the wormian bones are markers for various diseases and are important in the primary diagnosis of brittle bone disease osteogenesis imperfecta [3] neurocranial variables [4][5] which can be misleading in the diagnosis of fractures.

Materials and Methods The present study was carried out on dry skull bones from the Department of Anatomy at Goa Medical College and other neighboring medical colleges in India by examining the pterion, and its sutural articulations with frontal, parietal, sphenoid and temporal bones and also anatomical variations, if any, in adults.

Results In the present study, four types of pterion, i. When the data were compared among different populations, the percentage of types of pterion was found to be as given in [Table 1].

Bones of the Skull

Percentage distribution of types of pterion in different populations Discussion Pterion is an important anatomical landmark which is situated 4 cm above the midpoint of the zygomatic arch and 1 inch behind the frontozygomatic suture. One or more pterion ossicles or epipteric bones may appear between the sphenoidal angle, parietal and the greater wing of the sphenoid. They vary greatly in size, but are more or less symmetrical. Sutural bones appear in great numbers in hydrocephalic skulls and they have been linked with rapid cranial expansion.

Our earlier studies also reveal the presence of epipteric bones at pterion.

what bones meet at the pterion

This is an open access article distributed under the Creative Commons Attribution Licensewhich permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Abstract The pterion which marks the union of 4 bones of the cranium is located superior to the zygomatic arch and posterior to the frontozygomatic suture.

This study aims to analyze the location and types of pterion in adult Nigerian skulls. Bilateral sides of 37 adult dry skulls were studied. The pterion types were classified; linear distances from the centre of the pterion to the midpoint of the zygomatic arch and to the frontozygomatic suture were measured; these were analyzed for side and gender differences.

what bones meet at the pterion

Sphenoparietal was the most common pterion type The mean distances from the pterion to the midpoint of zygomatic arch were mm and mm in males and females, respectively, while the distances to the frontozygomatic suture were mm and mm.

The vertical position of the pterion was significantly higher in males than females.

what bones meet at the pterion

Bilateral occurrence is statistically insignificant. This information will be of neurosurgical and anthropological importance.

Pterion - Wikipedia

Introduction The pterion is a craniometric point near the sphenoid fontanelle of the skull. It is a point of convergence of the sutures between the frontal, sphenoid, parietal, and squamous temporal bones [ 1 ]. There are varied patterns of articulation of these bones and sometimes a small epipteric bone may be present.

There are four types of sutural pattern: The pterion is located superior to the zygomatic arch and posterior to the frontozygomatic suture.

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This area is known as the weakest part of the skull, yet it overlies the course of the anterior division of the middle meningeal artery [ 1 ], thus making it vulnerable to rupture, leading to extradural hematoma in the event of a blunt trauma to the side of the head [ 3 ].

Differences in the exact location of the pterion have been observed among different races, and this could be due to genetic or environmental influences affecting the craniometric indices of human skull. This study is thus of immense benefit to neurosurgical procedures on Nigerians skull.

what bones meet at the pterion

Materials and Methods Sixty-two dry human skulls from the Department of Human Anatomy, University of Ibadan, were assembled for this study. The cadavers were sourced from Lagos, Ile-Ife, Ibadan, and other cities within the southwestern region of Nigeria. Eruption of the third molar was used to identify the adult skulls.

Importance of Pterion - The Common Room

Thirty-seven adult skulls were selected for the study after exclusion of those with deformities and trauma affecting the landmarks for measurement, for example, fractures of the zygomatic arch. The skulls were divided into 21 males and 16 females using gross dimorphic characteristics for sexual characterization [ 1 ]. Inspection of the pterion was carried out and classified into four types: Measurements Figure 1 were taken on both sides of the skull from the pterion to the midpoint of zygoma MPZ and to the frontozygomatic suture FZS using a manual vernier calipers with an accuracy of 0.

Skull showing measurements taken from the pterion to the midpoint zygomatic arch MPZ and to the frontozygomatic suture FZS. Data obtained were analyzed using GraphPad Prism4 software.