The differences in facial anatomical structures of the major ethnic groups, may also be reflected in nasal resistance. Active anterior rhinomanometry (AAR) is the recommended technique for the objective assessment of nasal airway resistance (NAR). This study comprised of 85 adult Malay subjects. All the subjects had to undergo a primary assessment of relevant symptoms of nasal disease and nasal examination before undergoing AAR assessment. The mean value of total nasal airway resistance (NAR) was 0.19 Pa/cm(3)/s (ranged from 0.09 to 0.55 Pa/cm(3)/s) at 75 Pa pressure point and 0.24 Pa/cm(3)/s (ranged from 0.12 to 0.52 Pa/cm(3)/s) at 150 Pa pressure point. The mean unilateral NAR was 0.46 Pa/cm(3)/s at a reference pressure of 75 Pa and 0.51 Pa/cm(3)/s at a reference pressure of 150 Pa. In this study we presented normal values for NAR in healthy Malay adult subjects. AAR proves to be a valuable clinical method for recording and quantitating nasal resistance.
Acoustic rhinometry (AR) evaluates the geometry of the nasal cavity by measuring the minimum cross-sectional area (MCA) and nasal volume (V) by means of acoustic reflection. Understanding the normal and pathologic conditions of the internal nasal cavity using AR is important in the diagnosis of structural abnormalities in patients. The aim of this study was to investigate the normal range of AR parameters in healthy volunteers from three ethnic groups in Singapore: Chinese, Malay and Indian. We also attempted to evaluate the role of these measurements in the documentation of structural abnormalities in the nose. A total of 189 Singaporeans, aged > or = 18 years, were recruited from a nationwide survey study. They comprised 83 Chinese, 35 Malays and 71 Indians. Eighty-nine subjects had a rhinoscopically normal nose (Group 1), 77 had significant septal deviation (Group 2) and 23 had inferior turbinate hypertrophy (Group 3). AR was performed to measure the MCA at the anterior 1-5 cm from the nostril and the volume (V) between points at the nostril and 5 cm into the nose. A mean MCA (mMCA; equal to (L + R)/2) and a total volume (Vt; equal to L + R) were then calculated for each subject, where L and R refer to the measurements made for the left and right nostrils, respectively. The results showed that there was no statistically significant difference in mMCA (p = 0.80) and Vt (p = 0.60) among the three ethnic subgroups of Group 1. Statistically significant differences were found only between Groups 1 and 3 (p < 0.001 for both mMCA and Vt) and between Groups 2 and 3 (p = 0.001 for mMCA and p = 0.013 for Vt). Although there was no significant difference between Groups 1 and 2, significant differences in MCA (p = 0.001) and V (p = 0.040) were found between the narrower sides (smaller volume) and the wider sides in Group 2, indicating volume compensation between the nasal cavities. In conclusion, our study demonstrates that there is no significant difference in the normal range of AR measurements among Chinese, Malay and Indian ethnic groups. AR is able to determine the structural abnormality of the internal nasal cavity caused by septal deviation and inferior turbinate hypertrophy.
Nasal obstruction is a subjective complaint in patients with nasal disease. The ability to quantitate the nasal ventilation dysfunction would be useful for making the appropriate choice of nasal disease management. This cross-sectional study comprised of 200 adult subjects. They underwent assessment of relevant symptoms, nasal examination and investigations before undergoing active anterior rhinomanometry (AAR) assessment. A group of 88 normal subjects and 112 patients with nasal disease were included. The mean total nasal air resistance (NAR) was significantly higher in patients with nasal disease (0.33 Pa/cm(3)/s) as compared to normal subjects (0.24 Pa/cm(3)/s). There was no significant difference in total NAR between patients with symptoms of nasal obstruction and those without the symptoms (p = 0.42). It is concluded that AAR is a sensitive but not a specific tool for the detection of abnormalities in NAR and it failed to relate to the symptom of nasal obstruction.