This study aimed to assess the elevation of bone conduction threshold in patients with chronic otitis media and to investigate the mechanism of this phenomenon. One hundred and six patients with unilateral chronic otitis media who had undergone a tympanomastoidectomy were reviewed retrospectively. The differences in the bone conduction thresholds between the diseased and normal sides were assessed and compared according to the duration of the disease and the presence of cholesteatoma. Post-operative changes in the bone conduction threshold were also assessed. The mean bone conduction thresholds were significantly elevated on the diseased side, ranging from 3.4 to 11.6 dB across frequencies, with a maximal elevation at 2000 Hz. The duration of disease and the presence of cholesteatoma did not affect the degree of the bone conduction elevation. After ossicular reconstruction, bone conduction thresholds improved significantly at all frequencies, with the greatest improvement being observed at 2000 Hz. These results suggest that the elevation in the bone conduction threshold in chronic otitis media is mainly caused by a change in the conductive mechanism in the middle ear.

Cholesteatoma is a non-neoplastic, keratinising lesion which has two forms: congenital and acquired. Congenital cholesteatoma develops behind a normal, intact tympanic membrane, whilst acquired cholesteatoma is associated with a defect in the tympanic membrane. The pathological substrate of cholesteatoma is keratinising stratified squamous epithelium, but the origin of this epidermal tissue in the middle ear is controversial. Here, we review the most relevant and recent evidence for the principal aetiopathogenic theories of both forms of cholesteatoma, in the light of recent otopathological findings.

Congenital cholesteatoma is most plausibly explained by the persistence of fetal epidermoid formation. Conclusive ‘proof’ awaits the unambiguous demonstration of the metamorphosis of an epidermoid nidus into a lesion in vivo.

Acquired cholesteatoma may develop by various mechanisms: immigration, basal hyperplasia, retraction pocket and/or trauma (iatrogenic or non-iatrogenic). However, squamous metaplasia of the normal cuboidal epithelium of the middle ear is a highly unlikely explanation. Chronic inflammation seems to play a fundamental role in multiple aetiopathogenic mechanisms of acquired cholesteatoma. Therefore early treatment of inflammatory conditions might reduce their sequelae, perhaps by preventing the development of hyperplastic papillary protrusions.

Continued otopathological, cellular and molecular research would enhance our limited understanding of cholesteatoma and may lead to new therapeutic strategies for this erosive disease, which often defies surgical treatment.

Chronic otitis media (COM) patients who had a multichannel device implanted were evaluated regarding surgical problems and technical modifications. In a multicentric study, implantees whose aetiology was COM were retrospectively evaluated. Patients were operated on and evaluated at three different tertiary referral centres: SSK Izmir Hospital Cochlear Implantation (CI) Center (32 cases), Istanbul Marmara University ENT Clinic (six cases), Eskişehir Anadolu University CI Center (one case). Thirty-nine implantees were evaluated with respect to surgical problems, technical modifications, complications and hearing results. All patients had lost their hearings as a result of COM. Three out of 39 cases were children. Thirty-seven of the patients either had a radical cavity or ear converted to radical at the first stage or concomittantly with the implantation. Patients were evaluated in order to find out the best possible surgical solutions to specific problems caused by COM. In seven cases electrode array disrupted the epithelial lining of the cavity despite specific measures. Five of those cases were re-implanted, passing the electrode array through a tunnel under the facial nerve. Seven recent cases were also implanted with the same subfacial route. In all patients but one, satisfactory hearing results were achieved one to five years after implantation (SDS scores with monosyllabic word list were between 59 and 89 per cent, median 67.4 per cent). CI in COM patients necessitates technical modifications. In radical cavities subfacial implantation seems to be a good solution for the protection of the electrode array.