Nasal cycle in patients with septal deviation: Evaluation by acoustic rhinometry

The nasal cycle in patients with septal deviation was studied by acoustic r hinometric techniques. This study included 24 patients with anteriorly loca ted septal deviations (mean age = 23.5), and 26 normal controls (mean age = 24.7). Data of MCA (minimum cross-sectional area) and NV (nasal volume), c ollected in 20-minute intervals, were plotted for each subject during 8 hou rs. Twenty of 24 patients (83%) with septal deviation and 20 of 26 normal s ubjects (77%) showed at feast one complete cycle. Duration of the nasal cyc le, which ranged from 100 minutes to 400 minutes, had no statistical differ ence between the septal deviation group (mean duration of 216 minutes) and the normal control group (mean duration of 227 minutes). The degrees of var iation of MCA and NV, defined as Degree of Variation of MCA (%) = 100 (MCA( max) - MCA(min))/ MCA(max), Degree of variation of NV(%) = 100 (NV, NVmin)/ NVmax, which represent the percent change of MCA and NV throughout the stud y, showed no difference between the wide side and the narrow side, or betwe en the septal deviation group and the normal control group. These findings suggest that the nasal cycle is relatively independent of peripheral anatom ic factors for its generation. However, the amplitude of changes of MCA was greater in the wide side, and the sum of both MCAs tended to fluctuate in accordance with the fluctuation of MCA of the wide side. Thus, the nasal cy cle seemed to be affected by septal deviation.