title: The distance of the sigmoid sinus and the middle fossa dura from the external auditory canal in chronic otitis media.
abstract: OBJECTIVE
  Mastoid pneumatization is reduced in most patients suffering from chronic otitis media (COM). In most studies, the relationship between the degree of pneumatization and the distance of the sigmoid sinus from the external auditory canal has been examined, yielding different results. This study addresses the relationship between COM and the distance of the sigmoid sinus and also middle fossa dura from the external auditory canal.
  
  
  METHODS
  This was a case-control study on 15 adult COM patients, 12 traumatic facial palsy patients, and 15 cadaver temporal bones. After mastoidectomy, the distance between the spine of Henle and both the middle fossa dura and sigmoid sinus were measured, and the findings in each group was analyzed using Tukey's and ANOVA tests.
  
  
  RESULTS
  The average distance of the external auditory canal and the sigmoid sinus was 15.27 ± 3.3 mm in the COM group, 16.92 ± 3.23 mm in the traumatic facial palsy group, and 14.53 ± 2.92 mm in the cadaver temporal bones. There was no significant difference between the groups (p = 0.115). The average distance of the spine of Henle from the middle fossa dura was 6.73 ± 1.62 mm in the COM group, 11.4 ± 2.05 mm in the traumatic facial palsy group, and 8.93 ± 1.94 in the cadaver temporal bones. There was a significant difference between the groups (p < 0.001).
  
  
  CONCLUSIONS
  The distance of both the sigmoid sinus and the middle fossa dura from the external auditory canal (which indicates mastoid pneumatization) is reduced in COM patients.
authors.affiliation: Ear, Nose & Throat Research Center, Faculty of Medicine, Ghaem Hospital, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: M
authors.initials: M
authors.lastname: Rajati
authors.forename: A
authors.initials: A
authors.lastname: Shahabi
authors.forename: H
authors.initials: H
authors.lastname: Haghir
authors.forename: M
authors.initials: M
authors.lastname: Afzalaghaee
mesh_terms: D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D002102:Cadaver; D016022:Case-Control Studies; D002908:Chronic Disease; D003392:Cranial Sinuses / Q000000981:diagnostic imaging* / Q000473:pathology*; D004388:Dura Mater / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D004424:Ear Canal / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000601:surgery; D005158:Facial Paralysis / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008297:Male; D008416:Mastoid / Q000033:anatomy & histology / Q000000981:diagnostic imaging / Q000601:surgery; D008876:Middle Ear Ventilation / Q000379:methods; D010033:Otitis Media / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000503:physiopathology / Q000601:surgery; D012016:Reference Values; D018570:Risk Assessment; D013701:Temporal Bone / Q000033:anatomy & histology / Q000000981:diagnostic imaging / Q000601:surgery; D014057:Tomography, X-Ray Computed / Q000379:methods