title: Retromaxillary Pneumatization of Posterior Ethmoid Air Cells: Novel Description and Surgical Implications.
abstract: Retromaxillary pneumatization of posterior ethmoid (PE) air cells is an area that is yet to have appropriate description in rhinologic literature.
  
  
  
  Case series with chart review.
  
  
  
  Tertiary care hospital.
  
  
  
  First, 524 sides in 262 paranasal sinus computed tomography scans were analyzed: 350 normal sides were examined for PE pneumatization lateral to the sagittal plane of the medial wall of maxillary sinus posteriorly, and 174 diseased sides were similarly reviewed to check how pathology may affect identification and measurements. Following that, 153 operated sides in 84 cases prepared for revision endoscopic sinus surgery (ESS) were studied for residual diseased cells at different anatomic locations.
  
  
  
  Overall, retromaxillary PE pneumatization was identifiable in 416 of the 524 sides (79.4%). Lateral retromaxillary extension varied from 0.5 to 12.3 mm (mean ± SD, 4.8 ± 2.3 mm). This area of pneumatization is bounded anteroinferiorly by the junction between the posterior and superior walls of the maxillary sinus. Three cell types were described depending on the degree of lateral extension (type I, <3 mm; type II, 3-6 mm; type III, >6 mm). This cell, which we refer to as the Herzallah cell, was distinguishable from the anterior ethmoid Haller cell and was found to have residual disease in 50.3% of cases prepared for revision ESS.
  
  
  
  Retromaxillary extension of PE air cells varies considerably and requires attention during ESS. Residual undissected retromaxillary cell is a common finding in revision ESS and can contribute to inadequate disease clearance.
authors.affiliation: Department of Otorhinolaryngology, Faculty of Medicine, Zagazig University, Zagazig, Egypt ENT Department, King Abdullah Medical City, Makkah, Saudi Arabia iherzallah@gmail.com.
authors.forename: Islam R
authors.initials: IR
authors.lastname: Herzallah
authors.affiliation: ENT Department, King Abdullah Medical City, Makkah, Saudi Arabia Department of Otolaryngology, Al-Hada Armed Forces Hospital, Taif, Saudi Arabia.
authors.forename: Faisal A
authors.initials: FA
authors.lastname: Saati
authors.affiliation: ENT Department, King Abdullah Medical City, Makkah, Saudi Arabia Department of Otolaryngology, Umm Al-Qura University, Makkah, Saudi Arabia.
authors.forename: Osama A
authors.initials: OA
authors.lastname: Marglani
authors.affiliation: ENT Department, King Abdullah Medical City, Makkah, Saudi Arabia.
authors.forename: Rehab F
authors.initials: RF
authors.lastname: Simsim
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004724:Endoscopy; D005004:Ethmoid Bone / Q000000981:diagnostic imaging* / Q000473:pathology*; D005260:Female; D006801:Humans; D008297:Male; D008443:Maxillary Sinus / Q000000981:diagnostic imaging*; D008875:Middle Aged; D012189:Retrospective Studies; D012220:Rhinitis / Q000000981:diagnostic imaging* / Q000601:surgery*; D012852:Sinusitis / Q000000981:diagnostic imaging* / Q000601:surgery*; D014057:Tomography, X-Ray Computed
keywords: Haller cell; allergic fungal sinusitis; anatomical classification; anatomy variations; chronic rhinosinusitis; computed tomography; ethmomaxillary sinus; imaging; lamina papyracea; lateral sphenoid recess; nasal polyps; paranasal sinus; posterior ethmoids; prevention of residual disease; radiology; revision functional endoscopic sinus surgery; sphenomaxillary plate