title: Shape of the Osseous External Auditory Canal and Its Relationship to Troublesome Cavities.
abstract: OBJECTIVE
  On the basis of clinical observations, the shape of the osseous external auditory canal (OEAC) has often been seen as an etiological factor in troublesome cavities after modified radical mastoidectomy.
  
  
  METHODS
  Retrospective analysis of CT scans.
  
  
  METHODS
  To assess the role of the shape of the OEAC in troublesome modified radical cavities using computed tomographic scans of three groups of patients (without pathology and with or without draining cavities), we determined the depth of the pretympanic recess (DPTR) and its anterior curvature (ACPTR). In addition to looking at the shape of the OEAC, we also studied the role of any remaining mastoid air cells in relation to troublesome radical cavities, as well as the consultation frequency.
  
  
  RESULTS
  The DPTR was significantly deeper in draining cavities than in ears without pathology and dry cavities. No difference in the ACPTR was observed. The presence of remaining mastoid air cells is significantly associated with the presence of a troublesome radical cavity.
  
  
  CONCLUSIONS
  The shape of the OEAC (i.e., the DPTR) is a contributory factor to the drainage of modified radical cavities.
  
  
  METHODS
  4. Laryngoscope, 126:693-698, 2016.
authors.affiliation: Department of Otorhinolaryngology, Academic Medical Center, Amsterdam, the Netherlands.
authors.forename: Erik
authors.initials: E
authors.lastname: van Spronsen
authors.affiliation: Department of Otorhinolaryngology, Academic Medical Center, Amsterdam, the Netherlands.
authors.forename: Huibert F
authors.initials: HF
authors.lastname: van Waegeningh
authors.affiliation: Department of Otorhinolaryngology, Academic Medical Center, Amsterdam, the Netherlands.
authors.forename: Simon
authors.initials: S
authors.lastname: Geerse
authors.affiliation: Department of Otorhinolaryngology, Academic Medical Center, Amsterdam, the Netherlands.
authors.forename: Wytske J
authors.initials: WJ
authors.lastname: Fokkens
authors.affiliation: Department of Otorhinolaryngology, Academic Medical Center, Amsterdam, the Netherlands.
authors.forename: Fenna A
authors.initials: FA
authors.lastname: Ebbens
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D004424:Ear Canal / Q000000981:diagnostic imaging* / Q000503:physiopathology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D016015:Logistic Models; D008297:Male; D008416:Mastoid / Q000000981:diagnostic imaging* / Q000601:surgery; D008875:Middle Aged; D061330:Multidetector Computed Tomography / Q000379:methods*; D015999:Multivariate Analysis; D010032:Otitis Externa / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000601:surgery; D013506:Otologic Surgical Procedures / Q000379:methods; D012189:Retrospective Studies; D018570:Risk Assessment; D012720:Severity of Illness Index; D013701:Temporal Bone / Q000000981:diagnostic imaging* / Q000503:physiopathology
keywords: Ear canal; ear disease; radical cavity; tomography x-ray computed