title: Evaluation of using Bioglass®in obliteration of mastoid cavity.
abstract: BACKGROUND
  A mastoid cavity resulting from a canal wall down mastoidectomy can result in major morbidity for patients due to different open cavity problems. Mastoid obliteration with reconstruction of the bony external ear canal recreates the normal anatomy to avoid such morbidity.
  
  
  METHODS
  This retrospective observational study was conducted for 4 years (between 2008 - 2013) to determine if mastoid obliteration with bioactive glass (Bioglass®) following mastoidectomy overcomes the open cavity problems or not. Patients with cholesteatoma had subjected tomastoidectomy with primary or secondary mastoid obliteration, by using bioactive glass (Bioglass®),then our primary outcome measure.
  
  
  RESULTS
  Forty patients were interviewed. Forty of them were primary or secondary obliteration after canal wall down mastoidectomy of a primary cholesteatoma. The most frequent fate of obliteration or reconstruction of mastoid was Grade 1 (47.5%) then Grade 0 (30%). Postoperative hearing assessment showed that the average (mean) air conduction (0.5-4 KHz) was 31.1 dB and the average (mean) bone conduction (0.5-4 KHz) was 15.5 dB. The gain average in air conduction was 26 dB and in bone conduction it was 0.5 dB. Ear discharge was found in 36 patients (90%) preoperative and it was found only in 6 patients (15%) postoperative, in 4 patients (10%) cholesteatoma recidivism or recurrences was present.
  
  
  CONCLUSIONS
  This study shows that the bioactive glass (Bioglass®) is one of the beat materials used in mastoidectomy with obliteration of open mastoid cavity.
authors.affiliation: ENT Dept., Faculty of medicine, Al-Azhar University-Egypt.
authors.forename: Abdelrahman E M
authors.initials: AE
authors.lastname: Ezzat
authors.affiliation: ENT Dept., Faculty of medicine, Al-Azhar University-Egypt.
authors.forename: Mustafa I
authors.initials: MI
authors.lastname: Eid
keywords: Cholesteatoma; Mastoidectomy; Obliteration; bioactive glass (Bioglass®)