The lateralization percentage as a measure of nasal flow asymmetry in active anterior rhinomanometry.

A new parameter is introduced in active anterior rhinomanometry: the lateralization percentage, calculated as (right flow--left flow)/(right flow + left flow) x 100%. The flow was measured at 15 mm H2O pressure difference after induced shrinkage of the nasal mucosa. Two groups of subjects were studied. One group consisting of 28 male and 40 female volunteers was used to establish normal values in both sexes for flow, absolute flow difference and lateralization percentage. The second group consisting of 20 men who were to undergo submucous septal reconstruction for nasal obstruction was used to test the detection of abnormal cases when applying the normal values derived from the control group. It appeared that the absolute flow difference is a less effective measure than either the total flow or the lateralization percentage. Optimum detection (75-85% of the abnormal cases) was achieved by applying a criterion combining total flow and lateralization percentage.