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Ethmoid skull‐base height: a clinically relevant method of evaluation
Author(s) -
Ramakrishnan Vijay R.,
Suh Jeffrey D.,
Kennedy David W.
Publication year - 2011
Publication title -
international forum of allergy and rhinology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.503
H-Index - 46
eISSN - 2042-6984
pISSN - 2042-6976
DOI - 10.1002/alr.20062
Subject(s) - medicine , ethmoid sinus , coronal plane , skull , ethmoid bone , cribriform plate , orbit (dynamics) , sinus (botany) , frontal sinus , maxillary sinus , nuclear medicine , anatomy , orthodontics , surgery , nasal cavity , paranasal sinuses , botany , biology , genus , engineering , aerospace engineering
Background: The Keros classification scheme has been used to describe the ethmoid skull‐base configuration; however, this scheme only partially addresses key anatomic issues in ethmoid skull‐base injury avoidance during surgery. Methods: Coronal computed tomography (CT) scans were reviewed for 200 patients undergoing sinus evaluation at a tertiary care institution. Keros classification, maxillary sinus:ethmoid height ratio, and the skull‐base height:orbital height ratio were recorded for each patient. The Pearson correlation coefficient was used to determine if a relationship existed between the 3 sets of measurements. Results: In the Keros classification scheme, 42% of patients were in class I, 50% class II, and 8% class III. In maxillary sinus to ethmoid height ratio, 58% were 1:1, 37% were 2:1, and 5% were >2:1. In the skull‐base height to total orbital height ratio, 65% were in class I, 18% class II, and 17% in class III. There was no correlation between the classification schemes. Conclusion: The importance of the Keros classification lies primarily in the avoidance of iatrogenic injury to the cribriform region and medial ethmoid roof. To avoid penetration of the ethmoidal roof, the ethmoid skull‐base height must be separately examined in relation to the orbit and total vertical dimension of the sinuses.