title: Left-right differences in Eustachian tube function in children with ventilation tubes.
abstract: OBJECTIVE
  To study the intraindividual variation in Eustachian tube (ET) function in children with ventilation tubes.
  
  
  METHODS
  The forced response test, the pressure equilibration test and the sniff test were performed on both ears of 148 children. The results of both ears were compared.
  
  
  RESULTS
  No systematic differences were found between the left and the right ears. However, the intraindividual variation was very pronounced. The variation in passive ET function within children was of similar magnitude as the variation in passive ET function between children. Twenty-eight percent of the children had different active ET function in both ears and 15% had an opposite result in each ear with respect to the sniff test.
  
  
  CONCLUSIONS
  This study shows that ET function is much more a characteristic of the individual ear than of the individual child. These findings also question the validity of trials on ET function or middle ear disease that use the opposite ear as a control (split level design).
authors.affiliation: Department of Otorhinolaryngology, University Medical Center Nijmegen, Nijmegen, P.O. Box 9101, 6500 HB Nijmegen, Netherlands. n.vanheerbeek@kno.umcn.nl
authors.forename: Niels
authors.initials: N
authors.lastname: van Heerbeek
authors.forename: Annemiek E
authors.initials: AE
authors.lastname: Akkerman
authors.forename: Koen J A O
authors.initials: KJ
authors.lastname: Ingels
authors.forename: Joost A M
authors.initials: JA
authors.lastname: Engel
authors.forename: Gerhard A
authors.initials: GA
authors.lastname: Zielhuis
mesh_terms: D002648:Child; D002675:Child, Preschool; D002908:Chronic Disease; D005064:Eustachian Tube / Q000503:physiopathology*; D005260:Female; D006314:Hearing Loss, Conductive / Q000209:etiology / Q000503:physiopathology; D006801:Humans; D008297:Male; D008876:Middle Ear Ventilation; D010034:Otitis Media with Effusion / Q000150:complications / Q000503:physiopathology* / Q000601:surgery*; D011312:Pressure; D011379:Prognosis