Ambiguous "olfactory" terms for anatomic spaces adjacent to the cribriform plate: A publication database analysis and quest for uniformity

Position of the anterior ethmoidal foramen and trauma to the cranial base during transconjunctival medial orbital decompression: a systematic literature review

PURPOSE

To review the literature on the location of the anterior ethmoidal foramen (AEF) and trauma during transconjunctival medial wall decompression.

METHODS

A comprehensive literature search was conducted using the PubMed, Embase, and Scopus databases, combining the terms "olfactory fossa" and "fovea ethmoidalis" with "trauma," "cerebrospinal fluid leak," "pneumocephalus," "orbital decompression," and "anterior ethmoidal artery" (AEA). All cases of cranial base trauma during medial orbital decompression and the anatomical studies on the location of the AEF and the course of the AEA were reviewed.

RESULTS

Ninety-four articles were identified, of which 37 were related to the AEF, 41 reported the course of the AEA, and 16 to reported cases of cranial base trauma. Out of these cases, 10 were related to transconjunctival medial orbital decompression, affecting 11 patients. Most AEFs are situated at the frontoethmoidal suture, but up to 38.15% of AEFs are located above the suture on the frontal bone. Most AEFs are adjacent to the roof of the ethmoidal sinus. The distance of the AEF to the cranial base increases in the presence of supraorbital ethmoidal cells (SOEC).

CONCLUSIONS

The position of the AEF is variable and should not be considered a safe landmark for all patients.

The Relation of the Anterior Ethmoidal Foramen to the Cranial Base

PURPOSE

To perform a radiological analysis of the relation of the anterior ethmoidal foramen (AEF) to the cranial base and olfactory fossa (OF).

METHODS

Retrospective analysis of computed tomography coronal scans of 35 orbits of 35 patients with Graves orbitopathy. Following a standard multiplanar reconstruction of the orbit, the authors measured the vertical and the horizontal distances of the AEF to the cranial base and to the lateral border of the OF, respectively. The height of the OF was measured at the level of the AEF and at the position of Keros classification. The presence of supraorbital ethmoid cells (SOEC) was also recorded.

RESULTS

The vertical distance of the AEF to the cranial base ranged from 0.1 to 7.3 mm with a mean = 2.5 mm (SD = 2.17). In 47.5% of the orbits the foramen was adjacent (<1 mm) to the cranial base. The horizontal distance of the AEF to the lateral border of the OF ranged from 2.3 to 9.5 mm (mean = 5.4 mm, SD = 1.98). The presence of an SOEC (n = 12) increased significantly both the distance from the AEF to the cranial base and to the lateral border of the OF. The height of the OF at the level of AEF is not correlated with the depth of the OF at the level of Keros classification.

CONCLUSIONS

In the absence of supraorbital pneumatization, the AEF location is a dangerous landmark for the upper limit of the transconjunctival medial wall decompression.

Anatomy of the Calvaria and Skull Base

A thorough understanding of the skull anatomy is of key importance to radiologists as well as specialist physicians and surgeons. We describe the anatomy of the neurocranium comprising calvaria (the skull vault) and the skull base and discuss the most common and clinically relevant anatomic variants.