Nasal septal perforation is a structural or anatomical defect in the septum. The present study focused on the effects of septal perforation on nasal airflow and nasal patency, investigated using a computer simulation model.

The effect of nasal septal perforation size on nasal airflow pattern was analysed using computer-generated, three-dimensional nasal models reconstructed using data from magnetic resonance imaging scans of a healthy human subject. Computer-based simulations using computational fluid dynamics were then conducted to determine nasal airflow patterns.

The maximum velocity and wall shear stress were found always to occur in the downstream region of the septal perforation, and could potentially cause bleeding in that region, as previously reported. During the breathing process, there was flow exchange and flow reversal through the septal perforation, from the higher flow rate to the lower flow rate nostril side, especially for moderate and larger sized perforations.

In the breathing process of patients with septal perforations, there is airflow exchange from the higher flow rate to the lower flow rate nostril side, especially for moderate and large sized perforations. For relatively small septal perforations, the amount of cross-flow is negligible. This cross-flow may cause the whistling sound typically experienced by patients.