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Volume: 27 - Issue: 1

First page: 17 - Last page: 26

N. Hyo - H. Takano - Y. Hyo

DOI: 10.4193/Rhin10.4193/Rhin89.103

The deposition efficiency of therapeutic aerosol particles in the human maxillary
sinus is evaluated both in the human body and in a model cast of the upper airway. In
the experiments, three sample materials, such as mono-dispersed polystyrene latex
particles, aqueous glucose solution and pure water, in the range of particle diameter
offrom 0.5 to 15.8 pm, are employed in the model cast. The radioactive labelled aerosol
particle is also used in the human body. From the results of the experiment, it is
confirmed that even though the maxillary sinus is a closed hollow organ, aerosolflow
is able to be induced only when the pressure gradient is applied between the nasal
cavity and the maxillary sinus. In this case, the particle deposition is explained in
relationship to the inertia impaction of the aerosol particles on the inside wall of the
maxillary sinus. The total deposition efficiencies and the deposited particle sizes in
the sinus area for both experiments, with the model and in the human body, are
almost the same at 3%, and 3-10 itin in diameter, respectively. A physical model for
this particle deposition suggests that these experimental values change not only with
the size distributions of therapeutic particles and the pressure gradient, but also with
the diameter of the sinus ostium. Moreover, since the therapeutic particle might not
enter the maxillary sinus when the diameter of the sinus ostium canal is less than
1 mm, some pretreatment to open the sinus ostium canal would be necessary before
applying such aerosol therapy in practice.

Rhinology 27-1: 17-26, 1989