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Related Concept Videos

Cranial Bones: Lateral View01:27

Cranial Bones: Lateral View

The lateral view of the cranium is dominated by temporal, sphenoid, and ethmoid bones.
The temporal bone forms the lower lateral side of the skull. The temporal bone is subdivided into several regions. The flattened upper portion is the squamous portion of the temporal bone. Below this area and projecting anteriorly is the zygomatic process of the temporal bone, which forms the posterior portion of the zygomatic arch. Posteriorly is the mastoid portion of the temporal bone. Projecting...
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The superior view of the cranium shows the frontal and paired parietal bones.
The frontal bone is the single bone that forms the forehead. At its anterior midline, between the eyebrows, there is a slight depression called the glabella. The frontal bone also forms the supraorbital margin of the orbit. Near the middle of this margin is the supraorbital foramen, the opening that provides passage for a sensory nerve to the forehead. The frontal bone is thickened just above each supraorbital margin,...
Overview of the Skull01:08

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The cranium (skull) is the skeletal structure of the head that supports the face and protects the brain. It is subdivided into the facial bones and the brain case, or cranial vault. The facial bones underlie the facial structures, form the nasal cavity, enclose the eyeballs, and support the teeth of the upper and lower jaws.
The cranial vault surrounds and protects the brain and houses the middle and inner ear structures. This cavity is bounded superiorly by the rounded top of the skull, which...

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Related Experiment Video

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Midface Hypoplasia and Cranial Base Morphology in Syndromic Craniosynostosis: A Comparative Analysis Study Using a Predictive Regression Model
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Ethmoid skull-base height: a clinically relevant method of evaluation.

Vijay R Ramakrishnan1, Jeffrey D Suh, David W Kennedy

  • 1Department of Otolaryngology, University of Colorado Denver, Aurora, CO, USA. vijay.ramakrishnan@ucdenver.edu

International Forum of Allergy & Rhinology
|January 31, 2012
PubMed
Summary

The Keros classification aids in preventing surgical injury to the ethmoid skull base. However, separate measurements of ethmoid skull-base height relative to the orbit are crucial for complete injury avoidance.

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Area of Science:

  • Otolaryngology
  • Neurosurgery
  • Radiology

Background:

  • The Keros classification describes ethmoid skull-base anatomy but has limitations in surgical injury prevention.
  • Key anatomical factors for ethmoid skull-base injury avoidance are not fully addressed by the Keros scheme.

Purpose of the Study:

  • To evaluate the Keros classification and other measurements for describing ethmoid skull-base configuration.
  • To determine the correlation between Keros classification, maxillary sinus:ethmoid height ratio, and skull-base height:orbital height ratio.

Main Methods:

  • Coronal computed tomography (CT) scans of 200 patients were analyzed.
  • Keros classification, maxillary sinus:ethmoid height ratio, and skull-base height:orbital height ratio were recorded.
  • Pearson correlation coefficient was used to assess relationships between measurements.

Main Results:

  • Keros classification distribution: 42% class I, 50% class II, 8% class III.
  • Maxillary sinus to ethmoid height ratio: 58% 1:1, 37% 2:1, 5% >2:1.
  • Skull-base height to orbital height ratio: 65% class I, 18% class II, 17% class III.
  • No significant correlation was found between the classification schemes.

Conclusions:

  • The Keros classification is important for avoiding iatrogenic injury to the cribriform region and medial ethmoid roof.
  • Separate assessment of ethmoid skull-base height in relation to the orbit and sinus dimensions is necessary to prevent ethmoidal roof penetration.