Keros classification of olfactory fossa
Updates to Article Attributes
The Keros classification is a method of classifying the depth of the olfactory fossa.
The ethmoid labyrinth is covered by the fovea ethmoidalis of the frontal bone and separates the ethmoidal cells from the anterior cranial fossa.
The very thin, horizontal cribriform plate (lamina cribrosa) of the ethmoid bone is bounded laterally by the vertical lateral lamella. The lateral lamella joins the cribriform plate to the fovea ethmoidalis.
In adults, the olfactory recess is a variable depression in the cribriform plate that medially is bounded by the perpendicular plate and laterally by the lateral lamella. It contains olfactory nerves and a small artery.
The depth of the olfactory fossa is determined by the height of the lateral lamella of the cribriform plate. Predrag Keros, (1933-2018) 3 a Croatian physician, in 19621, and later Professor of Medicine at the University of Zagreb, classified the depth into three categories:
- type 1: has a depth of 1-3 mm (26.3% of population)
- type 2: has a depth of 4-7 mm (73.3% of population)
- type 3: has a depth of 8-16 mm (0.5% of population)
The type 3 essentially exposes more of the very thin cribriform plate to potential damage from trauma, tumour erosion, CSF erosion (in benign intracranial hypertension) and local nasal surgery or orbital/orbital decompression 2.
Thin bone in the skull base, especially the cribriform plate, is susceptible to erosion, encephalomeningocoeleencephalomeningocele herniation and CSF leaks
The most common sites of erosion or defects in the skull base are
- cribriform plate (51%)
- sphenoid lateral pterygoid recess (31%)
- ethmoid roof (8%)
- perisella
- inferolateral or pterygoid recesses
See also
-<p>The <strong>Keros classification</strong> is a method of classifying the depth of the <a href="/articles/olfactory-fossa">olfactory fossa</a>.</p><p>The ethmoid labyrinth is covered by the fovea ethmoidalis of the frontal bone and separates the ethmoidal cells from the <a href="/articles/anterior-cranial-fossa">anterior cranial fossa</a>.</p><p>The very thin, horizontal <a href="/articles/cribriform-plate">cribriform plate</a> (lamina cribrosa) of the ethmoid bone is bounded laterally by the vertical lateral lamella. The lateral lamella joins the cribriform plate to the <a href="/articles/fovea-ethmoidalis">fovea ethmoidalis</a>.</p><p>In adults, the olfactory recess is a variable depression in the <a href="/articles/cribriform-plate">cribriform plate</a> that medially is bounded by the perpendicular plate and laterally by the lateral lamella. It contains olfactory nerves and a small artery. </p><p>The depth of the olfactory fossa is determined by the height of the lateral lamella of the <a href="/articles/cribriform-plate">cribriform plate</a>. Keros in 1962<sup>1</sup>, classified the depth into three categories:</p><ul>- +<p>The <strong>Keros classification</strong> is a method of classifying the depth of the <a href="/articles/olfactory-fossa">olfactory fossa</a>.</p><p>The ethmoid labyrinth is covered by the fovea ethmoidalis of the frontal bone and separates the ethmoidal cells from the <a href="/articles/anterior-cranial-fossa">anterior cranial fossa</a>.</p><p>The very thin, horizontal <a title="Cribriform plate" href="/articles/cribriform-plate">cribriform plate (lamina cribrosa)</a> of the <a title="Ethmoid bone" href="/articles/ethmoid-bone-1">ethmoid bone</a> is bounded laterally by the vertical <a title="Lateral lamella" href="/articles/lateral-lamella">lateral lamella</a>. The lateral lamella joins the cribriform plate to the <a href="/articles/fovea-ethmoidalis">fovea ethmoidalis</a>.</p><p>In adults, the olfactory recess is a variable depression in the cribriform plate that medially is bounded by the perpendicular plate and laterally by the lateral lamella. It contains olfactory nerves and a small artery. </p><p>The depth of the olfactory fossa is determined by the height of the lateral lamella of the cribriform plate. <strong>Predrag Keros</strong>, (1933-2018) <sup>3 </sup>a Croatian physician, in 1962 <sup>1</sup>, and later Professor of Medicine at the University of Zagreb, classified the depth into three categories:</p><ul>
-</ul><p>The type 3 essentially exposes more of the very thin <a href="/articles/cribriform-plate">cribriform plate</a> to potential damage from trauma, tumour erosion, CSF erosion (in benign intracranial hypertension) and local nasal surgery or orbital decompression <sup>2</sup>.</p><p>Thin bone in the skull base, especially the <a href="/articles/cribriform-plate">cribriform plate</a>, is susceptible to erosion, encephalomeningocoele herniation and CSF leaks</p><p>The most common sites of erosion or defects in the skull base are</p><ul>-<li>-<a href="/articles/cribriform-plate">cribriform plate</a> (51%)</li>- +</ul><p>The type 3 essentially exposes more of the very thin cribriform plate to potential damage from trauma, tumour erosion, CSF erosion (in <a title="Benign intracranial hypertension" href="/articles/idiopathic-intracranial-hypertension-1">benign intracranial hypertension</a>) and local nasal surgery/orbital decompression <sup>2</sup>.</p><p>Thin bone in the skull base, especially the cribriform plate, is susceptible to erosion, <a title="Encephalocele" href="/articles/encephalocele-1">encephalomeningocele herniation</a> and CSF leaks</p><p>The most common sites of erosion or defects in the skull base are</p><ul>
- +<li>cribriform plate (51%)</li>
References changed:
- 3. Rotim K, Racz A. In memoriam: Professor emeritus Ph.D. Predrag Keros. Journal of Applied Health Sciences = Journal of Applied Health Sciences [Internet]. 2018 [accessed 02.07.2019]; 4 (1): 125-139. Available at: https://hrcak.srce.hr/199866
Unable to process the form. Check for errors and try again.