title: Tympanic membrane changes in central tympanic membrane perforations.
abstract: OBJECTIVE
  The objective of this study was to evaluate the histopathological changes in central tympanic membrane perforations caused by chronic otitis media without cholesteatoma.
  
  
  METHODS
  Twenty-nine temporal bones from 25 patients (13 male patients and 12 female patients) with central tympanic membrane perforations-18 chronic otitis media with perforation and 11 chronic otitis media with perforation caused by ventilation tubes-and 30 aged-matched normal temporal bones were included in this study. A scale was used to evaluate the extension of the migration of stratified squamous epithelium in the inner surface of the tympanic membrane. The thickness of tympanic membranes was measured halfway between the annular ligament and the perforation and compared with that of the normal bones. The presence of tympanosclerosis and papillary projections of squamous epithelium was also noted.
  
  
  RESULTS
  The extension of the migration of stratified squamous epithelium in the inner surface of the tympanic membrane was observed in 11 of the 29 perforations (38%). The thickness of tympanic membranes was significantly different between the perforation groups and the control group. Of the 29 tympanic membranes, 13 (44%) had tympanosclerosis and 8 (28%) revealed papillary projections of squamous epithelium.
  
  
  CONCLUSIONS
  Our study shows that a central tympanic perforation should not merely be considered as a simple defect. Most of the tympanic membranes showed one or more signs of sequelae or persistent abnormalities such as tympanosclerosis, papillary projections, thickening, and ingrowth without significant differences between the 2 central perforation groups.
authors.affiliation: Department of Otolaryngology, Otitis Media Research Center, University of Minnesota, Minneapolis, MN 55455, USA.
authors.forename: Mehmet F
authors.initials: MF
authors.lastname: Oktay
authors.forename: Sebahattin
authors.initials: S
authors.lastname: Cureoglu
authors.forename: Patricia A
authors.initials: PA
authors.lastname: Schachern
authors.forename: Michael M
authors.initials: MM
authors.lastname: Paparella
authors.forename: Shin
authors.initials: S
authors.lastname: Kariya
authors.forename: Hisaki
authors.initials: H
authors.lastname: Fukushima
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D004432:Ear, Middle / Q000473:pathology; D004848:Epithelium / Q000473:pathology; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D008876:Middle Ear Ventilation / Q000009:adverse effects / Q000295:instrumentation; D009092:Mucous Membrane / Q000473:pathology; D010033:Otitis Media / Q000150:complications / Q000473:pathology* / Q000628:therapy; D013701:Temporal Bone / Q000473:pathology*; D018058:Tympanic Membrane Perforation / Q000209:etiology / Q000473:pathology*