title: Bony sheathed chorda tympani: a unique case of incudomalleolar fixation.
abstract: OBJECTIVE
  To describe a unilateral conductive hearing loss caused by restriction of the movements of malleus and incus due to chorda tympani in a bony sheath.
  
  
  METHODS
  A 23-year-old man with a stable mild conductive hearing loss in the left ear and mild sensorineural hearing loss in the right ear.
  
  
  METHODS
  An exploratory tympanotomy was performed.
  
  
  METHODS
  Immobility of the ossicles due to a bony structure, which was found to be chorda tympani encircled in a bony sheath. Ossicular system regained its mobility with the severance of the chorda tympani.
  
  
  RESULTS
  Hearing was improved both subjectively and audiographically.
  
  
  CONCLUSIONS
  This is the second case of chorda tympani with a bony sheath and the first case of this pathologic finding affecting both malleus and incus. Bony sheathed chorda tympani is considered to be a congenital anomaly of the chorda tympani that causes incudomalleolar fixation and behaves as posterior bony bars.
authors.affiliation: Department of Otolaryngology Head and Neck Surgery, Hacettepe University Faculty of Medicine, Yenisehir, Ankara, Turkey. oaozmen@yahoo.com
authors.forename: Omer Afsin
authors.initials: OA
authors.lastname: Ozmen
authors.forename: Sarp
authors.initials: S
authors.lastname: Sarac
authors.forename: Levent
authors.initials: L
authors.lastname: Sennaroglu
authors.forename: Ergin
authors.initials: E
authors.lastname: Turan
mesh_terms: D000328:Adult; D001301:Audiometry, Pure-Tone; D002814:Chorda Tympani Nerve / Q000002:abnormalities* / Q000503:physiopathology / Q000601:surgery*; D004429:Ear Ossicles / Q000002:abnormalities* / Q000601:surgery*; D006314:Hearing Loss, Conductive / Q000175:diagnosis / Q000503:physiopathology; D006319:Hearing Loss, Sensorineural / Q000175:diagnosis / Q000503:physiopathology; D006801:Humans; D007188:Incus / Q000002:abnormalities* / Q000601:surgery*; D016268:Internal Fixators; D008297:Male; D008307:Malleus / Q000002:abnormalities* / Q000601:surgery*