DISTRIBUTION PATTERNS AND RELATIONSHIPS AMONG THE KEROS, GERA, AND YENIGUN CLASSIFICATION SYSTEMS IN THE MORPHOLOGICAL EVALUATION OF THE LATERAL LAMELLA OF THE CRIBRIFORM PLATE ON COMPUTED TOMOGRAPHY
Main Article Content
Abstract
Objective: To describe the distribution of risk levels according to Keros, Gera, and Yenigun classifications, and to analyze the relationships among these classifications as well as the correlation between the depth, angle, and length of the lateral lamella of the cribriform plate (LLCP) on computed tomography.
Subjects and methods: A cross-sectional descriptive study was conducted on 149 patients (298 nasal sides) at Nhan Dan Gia Dinh Hospital from June 2024 to June 2025. The study variables included olfactory fossa depth (Keros), lateral lamella angle (Gera), and lateral lamella length (Yenigun). Distribution normality was assessed using the Shapiro-Wilk test. Because both nasal sides from the same patient were included, the primary analyses were performed using Generalized Estimating Equations (GEE) with patient ID as the clustering unit; Spearman correlation analyses based on the mean value of both sides per patient were additionally reported.
Results: According to Keros classification, the medium-risk group (type II) predominated at 89.6%, while the high-risk group (type III) accounted for only 2.3%. In contrast, Gera classification identified a significantly higher proportion of high-risk cases (type III, angle < 45°) at 15.8%. The mean LLCP length was 11.83 ± 2.15 mm; Yenigun classification revealed that 7.0% of cases were in the high-risk group (type III > 15 mm). Statistical analysis showed that LLCP length varied independently of depth and angle. Notably, 95.2% of cases with a dangerous length (Yenigun type III) were concealed within the Keros low-to-medium risk groups.
Conclusion: The Keros classification alone does not fully reflect the multidimensional anatomy of the anterior skull base. In this sample, LLCP length according to the Yenigun classification behaved as a morphological parameter independent of depth and angle. Considering depth, angle, and length together may provide a more comprehensive preoperative assessment of high-risk LLCP variants.
Article Details
Keywords
Lateral lamella of cribriform plate, Keros classification, Gera classification, Yenigun classification, Computed tomography.
References
[2] Souza SA, Souza MMAd, Idagawa M, Wolosker ÂMB, Ajzen SA. Computed tomography assessment of the ethmoid roof: a relevant region at risk in endoscopic sinus surgery. Radiologia Brasileira. 2008;41:143–7. doi: 10.1590/S0100-39842008000300003.
[3] Kolak M, Kızılgöz V, Kantarci M. Examination of ethmoidal roof regarding Keros and Yenigun classifications in a Turkish population: a computerized tomography study. Surgical and Radiologic Anatomy. 2024;46(1):19–25. doi: 10.1007/s00276-023-03270-0.
[4] Yenigun A, Goktas SS, Dogan R, Eren SB, Ozturan O. A study of the anterior ethmoidal artery and a new classification of the ethmoid roof (Yenigun classification). European Archives of Oto-Rhino-Laryngology. 2016;273(11):3759–64. doi: 10.1007/s00405-016-4064-8.
[5] Preti A, Mozzanica F, Gera R, Gallo S, Zocchi J, Bandi F, et al. Horizontal lateral lamella as a risk factor for iatrogenic cerebrospinal fluid leak: Clinical retrospective evaluation of 24 cases. Rhinology. 2018;56(4):358–63. doi: 10.4193/Rhin18.103.
[6] Solares CA, Lee WT, Batra PS, Citardi MJ. Lateral lamella of the cribriform plate: software-enabled computed tomographic analysis and its clinical relevance in skull base surgery. Archives of Otolaryngology–Head & Neck Surgery. 2008;134(3):285–9. doi: 10.1001/archotol.134.3.285.