The effect of a middle meatal antrostomy on nitric oxide ventilation in the maxillary sinus.

The effects of middle meatal antrostomy (MMA) on air and nitric oxide exchange in the human maxillary sinus were quantified using the computational fluid dynamics technique. One full period of respiration was considered in the anatomically correct numerical domain. The simulation results showed that MMA did not cause any noticeable change in the velocity or pressure fields at a global level but induced local velocity as high as 0.21m/s inside the maxillary. Therefore, enlargement of the ostium area by MMA allows inspiratory and expiratory nasal airflow to induce significant convective flows in the sinus, which in turn enhances gas exchange dramatically. At the end of the inspiration phase, NO concentration in the maxillary sinus decreased to about 54% of the initial value. NO concentration decreased only by about 30% during the expiration phase. This difference in reduction rate is thought to result from the difference in airflow velocity in the extended ostium during inspiration vs. expiration.