Nejind The Haller cell is an air cell formed on the maxillary sinus medial roof with the pneumatization of the orbital inferomedial wall [ ]. In CT examination, the paranasal sinus is found in coronal cross-sections at the anterior region of the joint connecting the middle concha to the skull base. A horizontal plane was established by crossing the horizontal line with the infraorbital nerves. In cases where asymmetry was observed, 5. The low skull base-is it important? Cribriform plate lateral lamella depth values according to Keros classification.
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Abstract Objective: To determine the Keros classification and asymmetrical distribution rates of the ethmoid roof and the frequency of anatomic variations of the paranasal sinuses.
Materials and Methods: Paranasal sinus scans of patients obtained using computed tomography were evaluated retrospectively. Measurements were performed using a coronal plan with right-left comparison and with distance measurement techniques. The depth of the lateral lamella was calculated by subtracting the depth of the cribriform plate from the depth of the medial ethmoid roof.
The results were classified according to their Keros classification. Any asymmetries in the ethmoid roof depth and fovea ethmoidalis configuration were examined. The anatomic variations frequently encountered in paranasal sinuses pneumatized middle concha, paradoxical middle concha, agger nasi cells, Haller cells, Onodi cells, etc. The cases were classified as The most frequent variations were nasal septum deviation The most frequent classification was Keros Type II.
The paranasal sinus variations in each patient should be carefully evaluated. The data obtained from these evaluations can prevent probable complications by informing rhinologists performing endoscopic sinus surgery about preoperative and intraoperative processes. Introduction Currently, endoscopic sinus surgery ESS is extensively utilized. It is used not only for the treatment of chronic rhinosinusitis that is resistant to medical treatment but also in the treatment of a number of diseases such as nasal polyposis, mucocele, sellar and parasellar tumors, and optic nerve decompression [ 1 ].
There may be complications to endoscopic sinus surgery because it is performed in a complex region. These complications are divided into categories minor and major complications. Minor complications occur in 1.
The major complications are cerebrospinal fluid leakage, ocular traumatization, meningitis or intracranial vascular traumatization; these complications occur in 0—1. To minimize probable complications and to avoid major complications, anatomic variations, particularly in the base of the skull, should be properly understood. The majority of the major complications are related to the ethmoid bone.
The most complex and variable structure of the paranasal sinuses is the ethmoid sinus. The fovea ethmoidalis makes up the roof of the ethmoid bone labyrinth. The fovea ethmoidalis is a part of the frontal bone that separates the ethmoidal cells from the anterior cranial fossa.
The fovea ethmoidalis also medially connects with the lateral lamella of the cribriform plate Figure 1. The fovea ethmoidalis and lateral lamella are the most important parts of the skull base in terms of the risk of complication development during ESS [ 7 , 8 ].
Risk factors Abstract Keros and Gera classifications are widely used to assess the risk of skull base injury during endoscopic sinus surgery. Although, both classifications are useful preoperatively to stratify risk of patients going for surgery, it is not practical to measure the respective lengths during surgery. In this study, we aimed to propose a new radiological classification Thailand-Malaysia-Singapore TMS to assess the anatomical risk of anterior skull base injury using the orbital floor OF as a reference. A total of computed tomography images of paranasal sinuses sides were reviewed. The TMS classification has potential to be used for risk assessment of skull base injury among patients undergoing ESS. It serves as an additional assessment besides the Keros and Gera classifications. Understanding the computed tomography of paranasal sinus CT PNS variations in every patient and equipping oneself with the diverse anatomical knowledge is a prerequisite prior to surgery.
KEROS CLASSIFICATION PDF
Otolaryngol Head Neck Surg. Epub Mar Erratum in Otolaryngol Head Neck Surg. Comment in Otolaryngol Head Neck Surg. Objective We sought to identify a relationship between skull base height and anterior ethmoid artery AEA anatomy. Study Design Retrospective radiologic chart review. Setting University of Arkansas for Medical Sciences.