title: Acoustic rhinometry and paranasal cavities: a systematic study in box models.
abstract: OBJECTIVE
  Acoustic rhinometry (AR) is a well-established diagnostic tool in rhinology. The aim of the study was to test the hypothesis that the paranasal sinuses are a main cause for inaccuracy of AR in the posterior part of the nose.
  
  
  METHODS
  Experimental study to evaluate the influence of simulated paranasal sinus volume and of the contralateral side of the nose on AR measurements in "box models."
  
  
  METHODS
  Models were measured with paranasal sinus volume simulated between 0 and 25 mL and with the junction between the models and the paranasal sinuses varying in length and diameter.
  
  
  RESULTS
  Moderate but distinct modification of the posterior area-distance curve was found within the models after changing size of the paranasal sinuses and its junction to the cavity. The apparent cross-sectional area (CSA) measured in the posterior cavum decreased with the volume of the paranasal sinuses. This effect was limited by the length and the diameter of the paranasal junction, as well as by the concha. No influence of the contralateral side on AR measurements was seen.
  
  
  CONCLUSIONS
  Acoustic rhinometry reveals reproducible measurements up to 4 cm from the nostril that correspond with the actual model CSA. Simulated paranasal sinuses appear to partially contribute to the inaccuracy in the posterior part of the area-distance curve.
authors.affiliation: Klinik und Poliklinik für Hals-Nasen-Ohren-Kranke, Universität Würzburg, Würzburg, Germany. robert.mlynski@mail.uni-wuerzburg.de
authors.forename: Robert
authors.initials: R
authors.lastname: Mlynski
authors.forename: Stefan
authors.initials: S
authors.lastname: Grützenmacher
authors.forename: Christian
authors.initials: C
authors.lastname: Lang
authors.forename: Gunter
authors.initials: G
authors.lastname: Mlynski
mesh_terms: D006801:Humans; D008954:Models, Biological; D008961:Models, Structural; D009296:Nasal Cavity / Q000502:physiology*; D010256:Paranasal Sinuses / Q000502:physiology*; D012123:Pulmonary Ventilation; D015203:Reproducibility of Results; D023842:Rhinometry, Acoustic