title: Asymmetry of lateral lamella of the cribriform plate: a software-based analysis of coronal computed tomography and its clinical relevance in endoscopic sinus surgery.
abstract: BACKGROUND
  Endoscopic sinus surgery is a known approach for sinonasal pathologies. Due to close proximity of sinuses to orbits and brain, surgeon should be aware of sinonasal anatomy and associated variations. The roof of ethmoid (fovea ethmoidalis) separates the ethmoidal cells from the anterior cranial fossa. Medially the fovea attaches to the lateral lamella of the cribriform plate, which is the thinnest bone of the skull base. Hence, it is at a high risk of getting damaged during surgery.
  
  
  OBJECTIVE
  To ascertain the quantitative analysis of height of lateral lamella according to Keros classification in the computed tomographic (CT) images of patients presenting to our clinic.
  
  
  METHODS
  It was retrospective review of 77 CT scans using computerized software known as picture archiving and communication system. The height of lateral lamella was examined for both sides and then classified according to Keros classification. Asymmetry between two sides was also reported.
  
  
  RESULTS
  Keros type I was seen in 46 sides (29.8%), type II in 75 sides (48.7%) and type III was seen in 33 (21.4%) sides. Keros type I was seen in 38 sides in males and 8 sides in females. Type II was seen in 46 and 29 sides in males and females, respectively. Type III was seen in 18 sides in males and in 15 sides in females.
  
  
  CONCLUSIONS
  Understanding of the anatomy of ethmoid roof with its possible variation is crucial to give the surgeon optimal information about the possible risk that one can face during the surgery. Hence dreadful complications can be avoided.
authors.affiliation: Section of Otolaryngology and Head and Neck Surgery, Aga Khan University Hospital, Karachi, Pakistan, doc.adeel.khan@gmail.com.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Adeel
authors.forename: Mubasher
authors.initials: M
authors.lastname: Ikram
authors.forename: Mohammad Shaheryar Ahmed
authors.initials: MS
authors.lastname: Rajput
authors.forename: Asif
authors.initials: A
authors.lastname: Arain
authors.forename: Yasir Jamil
authors.initials: YJ
authors.lastname: Khattak
mesh_terms: D000293:Adolescent; D000328:Adult; D004724:Endoscopy; D005260:Female; D006801:Humans; D008297:Male; D010256:Paranasal Sinuses / Q000601:surgery; D012189:Retrospective Studies; D019291:Skull Base / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D012984:Software; D014057:Tomography, X-Ray Computed; D055815:Young Adult