title: Temporal bone study of Down's syndrome.
abstract: OBJECTIVE
  To study temporal bone histopathologic characteristics of the inner ear and middle ear cleft of patients with Down's syndrome.
  
  
  METHODS
  Sixteen temporal bones from eight patients with Down's syndrome were studied. Ten temporal bones from subjects without pathologic ear lesions but with congenital heart disease served as controls. The two-dimensional graphic reconstruction method proposed by Guild and modified by Schuknecht was used to study the cochleas; measurement of the vestibules was based on Igarashi's method.
  
  
  METHODS
  The temporal bone collection of the Otitis Media Research Center, Department of Otolaryngology, University of Minnesota School of Medicine, Minneapolis.
  
  
  RESULTS
  Six bones showed short cochlea, and four of six had Mondini's cochlea. The overall cochlear lengths in this study group were notably shorter than those of the controls. The spiral ganglion cell population and two of three vestibular dimensions also were notably less than the controls. Middle ear findings included residual mesenchyme, stapes abnormality, otitis media, and large facial canal dehiscence.
  
  
  CONCLUSIONS
  The difficulties encountered in rehabilitation of patients with Down's syndrome caused by mental retardation can be compounded by the hearing loss caused by middle and inner ear abnormalities. A complete evaluation of hearing loss and therapy before starting the rehabilitation gives the most favorable outcome.
authors.affiliation: Department of Otolaryngology, University of Minnesota School of Public Health, Minneapolis, USA.
authors.forename: H
authors.initials: H
authors.lastname: Bilgin
authors.forename: L
authors.initials: L
authors.lastname: Kasemsuwan
authors.forename: P A
authors.initials: PA
authors.lastname: Schachern
authors.forename: M M
authors.initials: MM
authors.lastname: Paparella
authors.forename: C T
authors.initials: CT
authors.lastname: Le
mesh_terms: D000293:Adolescent; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D003051:Cochlea / Q000002:abnormalities; D004314:Down Syndrome / Q000473:pathology*; D007758:Ear, Inner / Q000002:abnormalities*; D004432:Ear, Middle / Q000002:abnormalities; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D009925:Organ of Corti / Q000002:abnormalities; D012665:Semicircular Canals / Q000002:abnormalities; D013136:Spiral Ganglion / Q000002:abnormalities; D013701:Temporal Bone / Q000002:abnormalities*; D014722:Vestibule, Labyrinth / Q000002:abnormalities