Download PDF
CC BY-NC-ND 4.0 · Indian J Radiol Imaging 2018; 28(04): 395-400
DOI: 10.4103/ijri.IJRI_119_18
Neuroradiology & Head and Neck Imaging

Olfactory fossa depth: CT analysis of 1200 patients

Ashok Chirathalattu Babu
Department of Radiodiagnosis, Jubilee Mission Medical College and Research Institute, Thrissur, Kerala, India
,
Mattavana Ramakrishna Pillai Balachandran Nair
Department of Radiodiagnosis, Jubilee Mission Medical College and Research Institute, Thrissur, Kerala, India
,
Aneesh Mangalasseril Kuriakose
Department of Radiodiagnosis, Jubilee Mission Medical College and Research Institute, Thrissur, Kerala, India
› Author Affiliations
Subject Editor: Financial support and sponsorship Nil.
› Further Information
   Permissions and Reprints

Abstract

Background: Olfactory fossa (OF) is a depression in anterior cranial cavity whose floor is formed by cribriform plate of ethmoid. Lateral lamella, which forms its lateral boundary, is a thin plate of bone and is at risk of injury during functional endoscopic sinus surgery, especially when fossa is deep/asymmetric. Aims: To measure the variations in the depth of OF and categorize Kerala population as per Keros classification using computed tomography (CT). Settings and Design: This study was conducted in our institution from January 2016 to August 2017. Patients >16 years of age undergoing CT scan of paranasal sinuses (PNS) were included. Materials and Methods: Coronal PNS CT scan studies of 1200 patients were reviewed. The depth of OF was measured from vertical height of lateral lamella. Statistical Methods: Results were analyzed according to gender and laterality using independent sample t-test and Chi-square test. Results: The mean depth of OF was 5.26 ± 1.69 mm. Statistically significant difference was seen in the mean depth of OF between males and females but not between right and left sides. Keros type I was found on 420 sides (17.5%), type II in 1790 (74.6%), and type III on 190 sides (7.9%). Type III Keros was more on the right (9%) than left (6.8%) side, more in males (9.5%) than females (5.9%), and more among males on the right side (11.4%). Asymmetry in OF depth between two sides was seen in 75% of subjects. Conclusion: Prevalence of the dangerous type III OF, even though low, is significant especially among males and on the right side. Therefore, preoperative assessment of OF depth must be done to reduce iatrogenic complications.

Keywords

Functional endoscopic sinus surgery - Keros - olfactory fossa


Publication History

Article published online:
26 July 2021

© 2018. Indian Radiological Association. This is an open access article published by Thieme under the terms of the Creative Commons Attribution-NonDerivative-NonCommercial-License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commercial purposes, or adapted, remixed, transformed or built upon. (https://creativecommons.org/licenses/by-nc-nd/4.0/).

Thieme Medical and Scientific Publishers Private Ltd.
A-12, Second Floor, Sector -2, NOIDA -201301, India

 

  • References

  • 1 Erdem G, Erdem T, Miman MC, Ozturan O. A radiological anatomic study of the cribriform plate compared with constant structures. Rhinology 2004; 42: 225-9
    PubMedGoogle Scholar
  • 2 Cashman EC, MacMahon PJ, Smyth D. Computed tomography scans of paranasal sinuses before functional endoscopic sinus surgery. World J Radiol 2011; 3: 199
    CrossrefPubMedGoogle Scholar
  • 3 Jacob TG, Kaul JM. Morphology of the olfactory fossa – A new look. J Anatomic Soc India 2014; 63: 30-5
    CrossrefGoogle Scholar
  • 4 Vaid S, Vaid N. Normal anatomy and anatomic variants of the paranasal sinuses on computed tomography. Neuroimag Clin 2015; 25: 527-48
    CrossrefPubMedGoogle Scholar
  • 5 Som PM, Lawson W, Fatterpekar GM, Zinreich J. Embryology, Anatomy, physiology and imaging of the sinonasal cavities. In: Som PM, Curtin HD. editor Head and neck imaging. 5th ed. St. Louis, MO: Elsevier; 2011: 119-28
    Google Scholar
  • 6 Keros P. On the practical value of differences in the level of the lamina cribrosa of the ethmoid. Z Laryngol Rhinol Otol 1962; 41: 809-13
    PubMedGoogle Scholar
  • 7 Reddy UD, Dev B. Pictorial essay: Anatomical variations of paranasal sinuses on multidetector computed tomography – How does it help FESS surgeons?. Indian J Radiol Imag 2012; 22: 317
    Article in Thieme ConnectPubMedGoogle Scholar
  • 8 Paber JE, Salvador M, Villarta R. Radiographic analysis of the ethmoid roof based on Keros classification among Filipinos. Philipp J Otolaryngol Head Neck Surg 2008; 23: 15-9
    CrossrefGoogle Scholar
  • 9 Savvateeva DM, Güldner C, Murthum T, Bien S, Teymoortash A, Werner JA. et al. Digital volume tomography (DVT) measurements of the olfactory cleft and olfactory fossa. Acta Otolaryngol 2010; 130: 398-404
    CrossrefPubMedGoogle Scholar
  • 10 Dessi P, Moulin G, Triglia JM, Zanaret M, Cannoni M. Difference in the height of the right and left ethmoidal roofs: A possible risk factor for ethmoidal surgery. Prospective study of 150 CT scans. J Laryngol Otol 1994; 108: 261-2
    CrossrefPubMedGoogle Scholar
  • 11 Hoang JK, Eastwood JD, Tebbit CL, Glastonbury CM. Multiplanar sinus CT: A systematic approach to imaging before functional endoscopic sinus surgery. Am J Roentgenol 2010; 194: W527-36
    CrossrefPubMedGoogle Scholar
  • 12 IBM Corp. Released 2011. IBM SPSS Statistics for Windows, Version 20.0. Armonk, NY: IBM Corp;
    Google Scholar
  • 13 Salroo IN, Dar NH, Yousuf A, Lone KS. Computerised tomographic profile of ethmoid roof on basis of keros classification among ethnic Kashmiri’s. Int J Otorhinolaryngol Head Neck Surg 2016; 2: 1-5
    CrossrefGoogle Scholar
  • 14 Pawar A, Konde S, Bhole P. Assessment of depth of olfactory fossa in pre-functional endoscopic sinus surgery computed tomography scan of paranasal sinuses. Int J Otorhinolaryngol Head Neck Surg 2017; 4: 83-6
    CrossrefGoogle Scholar
  • 15 Nair S. Importance of ethmoidal roof in endoscopic sinus surgery. Sci Rep 2012; 1: 1-3
    Google Scholar
  • 16 Ali A, Kurien M, Shyamkumar NK. Anterior skull base: High risk areas in endoscopic sinus surgery in chronic rhinosinusitis: A computed tomographic analysis. Indian J Otolaryngol Head Neck Surg 2005; 57: 5-8
    CrossrefPubMedGoogle Scholar
  • 17 Gupta P, Ramesh P. Radiological observation of ethmoid roof on basis of keros classification and its application in endonasal surgery. Int J Anat Res 2017; 5: 4204-7
    CrossrefGoogle Scholar
  • 18 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. Arch Otolaryngol Head Neck Surg 2008; 134: 285-9
    CrossrefPubMedGoogle Scholar
  • 19 Gauba V, Saleh GM, Dua G, Agarwal S, Ell S, Vize C. Radiological classification of anterior skull base anatomy prior to performing medial orbital wall decompression. Orbit 2006; 25: 93-6
    CrossrefPubMedGoogle Scholar
  • 20 Floreani SR, Nair SB, Switajewski MC, Wormald PJ. Endoscopic anterior ethmoidal artery ligation: A cadaver study. Laryngoscope 2006; 116: 1263-7
    CrossrefPubMedGoogle Scholar
  • 21 Souza SA, Souza MM, Idagawa M, Wolosker ÂM, Ajzen SA. Computed tomography assessment of the ethmoid roof: A relevant region at risk in endoscopic sinus surgery. Radiol Bras 2008; 41: 143-7
    CrossrefGoogle Scholar
  • 22 Nitinavakarn B, Thanaviratananich S, Sangsilp N. Anatomical variations of the lateral nasal wall and paranasal sinuses: A CT study for endoscopic sinus surgery (ESS) in Thai patients. J Med Assoc Thai 2005; 88: 763-8
    PubMedGoogle Scholar