title: Air-bone gap in ears with a well-repaired tympanic membrane after Type III and Type IV tympanoplasty.
abstract: OBJECTIVE
  To investigate the air-bone conduction hearing gap (A-B gap) after Type III and Type IV stapes columella tympanoplasty in ears with mobile stapes and a well repaired tympanic membrane (TM).
  
  
  METHODS
  Those patients who underwent tympanoplasty in our hospital between 2003 and 2009 and satisfied the following criteria were eligible: (1) good stapes mobility, confirmed intraoperatively; (2) postoperative TM and/or computed tomography (CT) findings that showed a well-aerated tympanic cavity without TM perforation, otorrhea, or middle ear effusion; and (3) measurable air and bone conduction hearing thresholds 1 year postoperatively at all test frequencies (250 Hz, 500 Hz, 1 kHz, 2 kHz, and 4 kHz).
  
  
  RESULTS
  Hearing results were better after Type III tympanoplasty than after Type IV tympanoplasty. After Type III (n=70) and Type IV (n=24) tympanoplasty, the respective mean A-B gaps were 16.4 ± 7.2 dB and 20.1 ± 5.6 dB, respectively. The mean A-B gap was significantly smaller after Type III tympanoplasty than after Type IV tympanoplasty (p<0.05). Regardless of the type of tympanoplasty, the postoperative A-B gap was greatest at 4 kHz.
  
  
  CONCLUSIONS
  The mean A-B gap was smaller after Type III tympanoplasty than after Type IV tympanoplasty. The magnitude of the A-B gap was greatest at 4 kHz in both procedures.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Ehime University, Shitsukawa, Toon City, Ehime 791-0295, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Okada
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Ehime University, Shitsukawa, Toon City, Ehime 791-0295, Japan. Electronic address: kiyofumi@m.ehime-u.ac.jp.
authors.forename: Kiyofumi
authors.initials: K
authors.lastname: Gyo
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Ehime University, Shitsukawa, Toon City, Ehime 791-0295, Japan.
authors.forename: Taro
authors.initials: T
authors.lastname: Takagi
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Ehime University, Shitsukawa, Toon City, Ehime 791-0295, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Fujiwara
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Ehime University, Shitsukawa, Toon City, Ehime 791-0295, Japan.
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Takahashi
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Ehime University, Shitsukawa, Toon City, Ehime 791-0295, Japan.
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Hakuba
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Ehime University, Shitsukawa, Toon City, Ehime 791-0295, Japan.
authors.forename: Naohito
authors.initials: N
authors.lastname: Hato
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001299:Audiometry; D001844:Bone Conduction; D002648:Child; D002781:Cholesteatoma / Q000151:congenital / Q000601:surgery; D018424:Cholesteatoma, Middle Ear / Q000601:surgery*; D002908:Chronic Disease; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D063371:Myringosclerosis / Q000601:surgery*; D010033:Otitis Media / Q000601:surgery*; D012189:Retrospective Studies; D016896:Treatment Outcome; D014433:Tympanoplasty / Q000379:methods*; D055815:Young Adult
keywords: Aeration of tympanic cavity; Columella; Middle ear mechanics; Ossicular reconstruction; Stapes mobility