Objective: Ciliary-beat frequency (CBF) is an important factor influen
cing mucociliary flow in the respiratory tract. A significant correlat
ion exists between CBF and mucus transport time (MTT), which suggests
that CBF is the main factor in nasal mucociliary clearance in healthy
individuals. Mucociliary clearance is influenced by the temperature of
the inspired air and decreases at temperatures below 33 degrees C. It
is unknown whether CBF varies in different sites within the nasal cha
mber and exactly how CBF is altered in disease states such as chronic
sinusitis (CS) and nasal polyposis (NP). Our study was conducted in an
attempt to answer these questions. Method: CBF was measured in nasal
biopsies from eight normal control subjects: 6 CS and 8 NP patients. B
iopsies from the regions of the maxillary, ethmoid, frontal, and sphen
oid sinus ostia were also obtained. The material was analyzed using a
computerized image-processing system. Results: Our data demonstrated a
significant decrease in CBF at 22 degrees C compared to at 35 degrees
C for all sinus biopsies (p < .05). We found no statistical differenc
e between the CBF of biopsies from the regions of the various sinus os
tia. A comparison between the patients with CS and normal controls aga
in revealed no significant difference in CBF, a finding which contradi
cts previously published reports. Surprisingly, an increase in CBF was
observed in NP patients compared to control and CS patients (p < .05)
. Conclusions: We conclude that our technique is a viable model for st
udying sinonasal CBF in the human. Our data suggest that a mechanism o
ther than decreased CBF may account for the decreased mucociliary clea
rance observed in chronic sinusitis.