Dimensions and resistances of the human nose: racial differences

Dimensions of the external nose and nostrils and nasal airflow resistances were determined in healthy, young Caucasian, Oriental, and Negro adults. Statistically significant variation between racial groups was found in nasal width and the differential between dorsi-ventral and transverse nostril diameters. Corresponding differences were found also in nasal airflow resistances of combined and separate nasal cavities in both the untreated and decongested state. Caucasian noses were leptorrhine, Negro noses were platyrrhine, and Oriental noses were of intermediate dimension. Mean nasal resistances of untreated noses were 0.129 Pa/cm3/sec in Negroes (N = 17), 0.146 in Orientals (N = 20), and 0.184 in Caucasians (N = 24), and differences were more marked when noses were decongested (P less than 0.05 in all cases). Ratios between resistances of untreated and decongested noses showed no statistical differences between racial groups, suggesting a similarity in the mucovascular component of resistances.     

Characteristics of pediatric nasal airway resistance

The nasal airway resistance (NAR) was determined in 739 normal children and 20 patients with enlarged adenoids by means of anterior rhinomanometry. It was demonstrated that the normal value of NAR in children ranged between 1.96 and 5.26 cmH2O.s/L (1 cmH2O = 0.098 kPa) with extensive distributions and great inter-personal variations. There was no significant difference of NAR between male and female in different age groups (P greater than 0.05). Adenoidal proliferation played an important role in determining the pediatric NAR. The NAR changes may be closely related to anatomical and physiological changes occurring in the nose with growing.     

Rhinometry: Spectrum of nasal profile among Nigerian Africans

Nasal parameters measurements are useful in anthropology to distinguish people into racial and ethnic groups.Materials and methodsA cross-sectional survey among Nigerians aged 18 to 70 years of Nigerian parentage randomly selected at the ENT Clinic of the University of Ilorin teaching hospital (U.I.T.H.), Ilorin, Nigeria without gender discrimination had measurement of their nasal parameters done using a sliding caliper: Nasal height, width, tip protrusion, alar thickness, nasal septal thickness and nares diameter.Results105 subjects were seen, the age range 18 to 70 years (mean of 28.63 + 13.06 years). There was 58 males and 47 females with a male/female ratio of 1.2:1. The mean nasal width/height (Nasal index -NI) was 90.7 in males and 88.2 in females. Males had a higher NI compared to female (p < 0.03). The commonest type of nasal variability is Type A (70.5%), Platyrrhine nose, Type B (26.7%) especially in females (mesorrhine) and Type C (leptorrhine) (2.8%).ConclusionsThere is significant association between the sex of an individual and type of Nose. Platyrrhine nose, among males and mesorrhine among females, only 2.8% being leptorrhine. The nasal indices were higher in males than in females.     

Objective assessment of nasal resistance in patients with nasal disease

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.     

Nasal nitric oxide and the nasal cycle

OBJECTIVES: To establish the relationship between nasal patency and the nitric oxide (NO) concentration in the nasal airways. METHODS: Unilateral nasal NO concentration (n = 11) and inhaled nasal NO concentration at oropharynx (n = 9) were measured in healthy adult volunteers. Subjects breathed normally through the nose with a known resistance (ranged from none to total occlusion) placed in one nostril. In a subgroup (n = 7), the unilateral nasal NO concentrations were determined with nasal cavity congestion induced by lateral decubitus. RESULTS: When the added nasal resistance was less than 6 cm H(2)0 per liter per second, the peak NO concentrations in the nose remained below 80 parts per billion (ppb). Thereafter, the higher the resistance, the greater the NO concentration. It was up to 1109.7 ppb when the front nostril was totally occluded. There was no correlation between oropharyngeal NO concentrations and resistance in the front of the nose (r = 0.4). There was a significantly negative correlation between nasal cavity volumes and nasal NO concentrations (r = -0.8, P <.001). CONCLUSIONS: Increases in nasal resistance to levels encountered in the nasal cycle and in recumbency augments the NO concentration within the obstructed side of the nose. Although that within the nose changes with patency, the NO concentration is constant down to the lower airways. The modulation role of the upper airways to the inhaled NO concentration remains unclear.     

Unilateral and bilateral nasal resistances

Plethysmographic rhinomanometric resistance measurements of combined and separate nasal cavities were made at a transnasal differential pressure of 100 Pa. The coefficients of variation over time of 40 consecutive total resistance values obtained at 1 min intervals from untreated noses of five healthy subjects averaged 11.0% measured directly and 11.8% calculated by application of Ohm's Law for parallel resistors. Measurements at 5 min intervals between sides increased variation of calculated total resistances markedly. The coefficients decreased to 4.7% and 5.1% respectively when the noses were decongested and by contrast with untreated noses these resistances varied independently from each other. Facial masking increased the coefficient of variation of resistance in the decongested nose (p less than 0.001) to as much as 11.0% and the magnitude of averaged resistances was moderately increased also (p less than 0.035). Measured values plotted against calculated values for total nasal resistance of 45 consecutive patients produced a regression differing insignificantly (p = 0.94) from the line of identity in the decongested nose but diverging from it (intercept 0.03 Pa/cm3/sec and slope 0.83, p less than 0.03) when the nose was untreated. Resistive variations associated with mucovascular instability and with use of a face-mask contribute substantially to differences between the results of anterior and posterior rhinomanometric assessments of total nasal resistance.     

Assessment of nasal obstruction. A comparison between rhinomanometry and nasal inspiratory peak flow

In several conditions objective assessment of nasal obstruction would be of great value. In this study we have compared two different methods for this purpose. Anterior rhinomanometry is a well established method, which measures nasal airway resistance (NAR). This was compared with nasal inspiratory peak flow (NIPF) measured with a Youlten peak flow meter. The assessments were undertaken in patients with allergic rhinitis, before and after challenge with hyperosmolar saline solution. After challenge there was a fall in NIPF value as a mean of 17.4%, that was mirrored by a rise in NAR of 15.6%. There was also a statistically significant negative linear correlation between these two methods (p less than 0.01). We conclude that NIPF is a cheap, easily performed and quick method suitable for assessing nasal airway patency in e.g. allergics during treatment and during challenge.     

体位变化对健康儿童鼻腔及鼻咽气道几何形态和鼻气道阻力的影响

目的研究健康儿童不同体位下声反射鼻腔测量参数，探讨体位变化对鼻腔几何形态和鼻阻力的影响情况。方法将73例健康儿童按年龄分组：3～6岁组、7～10岁组及11～14岁组，对其进行声反射鼻腔测量，得到坐位、仰卧位及侧卧位时的声反射鼻腔测量参数值，包括鼻腔和鼻咽容积以及鼻阻力的变化。结果各年龄组左侧卧位、右侧卧位及仰卧位总鼻气道阻力比坐位时增大（P〈0．05），左侧卧位与右侧卧位、仰卧位总鼻气道阻力对比差异无统计学意义（P〉0．05）。左侧卧位、右侧卧位及仰卧位双侧鼻腔容积（nasal cavity volume，NCV）、双侧鼻咽容积（nasopharyngeal volume，NPV）及总鼻腔最小横断面积（nasal minimal cross-sectional area，NMCA）与坐位比较减小，差异具有统计学意义（P〈0．05）；左侧卧位、右侧卧位及仰卧位相比差异无统计学意义（P〉0．05）。3～6岁组坐位总鼻气道阻力与7～10岁组、11～14岁组比较增大，7～10岁组总鼻气道阻力与11～14岁比较增大，差异均有统计学意义（P值均〈0．05）。3～6岁组坐位双侧NCV、双侧NPV及总NMCA较7～10岁组、11～14岁组减小，7～10岁组与11～14岁组比较减小，差异均具有统计学意义（P值均〈0．05）。结论体位变化在儿童亦可引发与成人相似的鼻腔几何学和气流动力学的变化。声反射鼻腔测量在研究儿童鼻及鼻咽部气道几何形态方面具有重要的意义。     

The effects of nasal massage of the "yingxiang" acupuncture point on nasal airway resistance and sensation of nasal airflow in patients with nasal congestion associated with acute upper respiratory tract infection

The aim of our study was to determine whether nasal massage of the "yingxiang" acupuncture point in patients with nasal congestion had any effect on nasal airway resistance (NAR) measured by posterior rhinomanometry and sensation of nasal airflow measured on a visual analog scale (VAS). Twenty patients were randomized into two groups; one group self massaged the yingxiang point for 30 seconds, while the other group acted as control group without nasal massage. NAR and VAS were measured at baseline, and at 2 and 10 minutes after massage. At the end of the study, patients were asked to score any change in their nasal congestion. There was no statistically significant difference between the two groups in percentage change in NAR or VAS from baseline at any time during the study, although the massage group showed trends toward decongestion and relief from congestion. At the end of the study, more patients in the massage group than the control group felt their nasal congestion was improved (p < 0.005). It is interesting that all three measures (NAR, VAS, and end question) showed that the nasal massage group had greater relief from nasal congestion than the control group. The results of this study, when taken together, indicate that nasal massage may provide some relief from nasal congestion and that further studies involving a larger patient population are warranted to determine whether nasal massage has a significant effect on NAR.     

The obstructive nasal septum. Effect of simulated deviations on nasal airflow resistance

Effects of simulated septal deviations on nasal airflow resistances were assessed by rhinomanometry in healthy human adults. Obstructions 5 x 15 mm protruding 1 to 5 mm into the nasal lumen were applied to the septum in untreated and decongested nasal cavities. The most resistive septal site was located opposite the caudal edge of the upper lateral cartilage where a 3-mm deviation increased resistance substantially in untreated noses, but produced no resistive effect when the mucosa was decongested, whereas a 4-mm deviation increased resistance severely at this site in untreated and decongested noses. Deviations at the caudal end of the septum that overlapped the upper lateral cartilage were markedly resistive also, while near the cavum they were less resistive. Decongestion reduced resistance and length of this anterior-resistive nasal segment. By contrast, within the cavum neither deviations of 5 mm nor mucosal status affected resistance. It is concluded that airflow resistance of the nasal cavum is unresponsive to septal deviations and mucosal status, but the anterior part of the nose is most susceptible and differences of 1 mm in lumen can be critical.     

鼻声反射和鼻阻力检查在气道炎症应用中的评价

目的探讨在上下气道炎症研究中鼻声反射、鼻阻力检查的参数选择及临床应用价值。方法应用鼻声反射仪及鼻阻力计对变应性鼻炎、哮喘患者及正常人鼻激发试验前后鼻腔通气功能进行测量,比较两种检查方法的差异,分析上下气道炎症的关系。结果①与正常对照组比较,鼻激发试验前后变应性鼻炎组、哮喘组鼻腔容积（nasal volume,NV）变化有显著性差异（P〈0．05）,鼻腔阻力（nasal airway resistance,NAR）变化也有显著性差异（P〈0．05）。②变应性鼻炎组、哮喘组NV与NAR变化率均呈负相关（r鼻炎=-0．673;r哮喘=-0．497,P〈0．01）,但NAR变异系数（coefficient of variation,CV）较大。正常组NV与NAR变化率无明显相关（r正常组=0．120,P〉0．05）。③以鼻声反射NV减少20％或NAR增加20％作为阳性标准,变应性鼻炎组、哮喘组与正常对照组NV阳性率的差异有统计学意义（X^2=23．03,P〈0．01）,NAR阳性率差异也有统计学意义（X^2=28．06,P〈0．01）。结论①AR、NAR检查均可作为评价鼻激发试验（nasal provocation testing,NPT）前后鼻腔通气功能的客观检查,但是,AR比NAR检查更为简便、迅速,精确度更高,重复性更好。②上、下气道炎症存在密切相关性。     

Objective and subjective evaluation of endoscopic nasal surgery outcomes

BACKGROUND: Chronic rhinosinusitis (CRS) symptoms include nasal obstruction, rhinorrhea, and facial pain associated with rhinosinusitis disability. When resistance to medical treatment is associated with endonasal anomalies, endoscopic nasal surgery (ENS) can be proposed. However, objective and subjective assessment criteria regarding the evaluation of ENS outcomes remain unclear. The aims of this study were to evaluate the correlation between the inflammation in the nasal mucosa, objective recordings of nasal airway resistance (NAR), subjective evaluation of symptom intensity, and the impact of ENS on patient-perceived rhinosinusitis disability. METHODS: Sixty-one consecutive patients (35 men and 26 women; mean age, 37.5 years) suffering from CRS were monitored at 4 months and 2 years after ENS. All middle turbinate mucosa were analyzed for the density of nonspecific inflammatory cells. All patients scored their own subjective rhinosinusitis symptoms and complaints of rhinosinusitis disability. An active anterior rhinomanometry was performed. RESULTS: A good correlation was observed between subjective and objective NAR (p < 0.001). We found a significant correlation between the density of inflammatory cells in the nasal mucosa, subjective nasal obstruction, and the rhinosinusitis disability score (p < 0.001). Recurrent CRS was seen only in subjects with moderate to severe inflammation of the middle turbinate mucosa sampled at the first surgical intervention. Subjective rhinosinusitis symptoms, objective NAR, and rhinosinusitis disability improved significantly after ENS. CONCLUSION: The degree of inflammation seems to be a good prognostic indicator regarding CRS recurrence. Long-term outcome after ENS for CRS showed significant improvement in subjective rhinosinusitis-specific symptoms, objective NAR, and rhinosinusitis disability.     

Influence of maxillary morphology on nasal airway resistance in Marfan's syndrome

High nasal airway resistance (NAR) has been reported in Marfan's syndrome, and this appears to contribute to the development of obstructive sleep apnoea in these patients. The cause of high NAR in Marfan's syndrome is unknown, but these patients characteristically have a narrow maxilla, which could have an influence on nasal dimensions. The aim of this study was to define the mechanism(s) mediating high NAR in Marfan's syndrome. Five patients with Marfan's syndrome (mean age 29+/-4 (SEM) years) were compared with an equivalent number of normal control subjects (31+/-1 years). NAR was measured by posterior rhinomanometry, before and after topical decongestant, nasal stenting, or both. Dental impressions were taken to evaluate maxillary arch morphology, allowing measurement of the following lateral distances: inter-canine (ICD), inter-premolar (IPD), and inter-molar (IMD). NAR (at a flow of 500 ccm/s) was considerably higher in patients compared with controls at baseline (0.93+/-0.08 vs 0.35+/-0.08 Pa/ccm/s, p < 0.001), and following decongestant and/or stenting. The maxillary arch was considerably narrower in patients. There were strong inverse correlations between the lateral maxillary dimensions and NAR after nasal decongestant, with or without stenting. These results indicate a strong association between maxillary width and NAR, and suggest that maxillary constriction is the dominant mechanism for the high NAR in Marfan's syndrome. The therapeutic implications of this finding warrant further investigation.     

Nasal airflow asymmetry and the effects of a topical nasal decongestant.

Nasal airway resistance (NAR) is normally asymmetrical due to the nasal cycle. The aims of this study were to determine the degree of this asymmetry in healthy subjects and those with acute rhinitis associated with common cold, and to investigate how the administration of a topical nasal decongestant (xylometazoline) influenced the asymmetry in NAR. Unilateral NAR was measured by active anterior rhinomanometry, and was shown to be asymmetrical in both healthy subjects and those suffering with acute rhinitis. The asymmetry in NAR was greater in those with acute rhinitis than in the healthy group, with a ratio between "high" and "low" sides of 2.3:1 in the rhinitis group compared to a ratio of 1.7:1 in the healthy subjects. Administration of a topical nasal decongestant caused a significant decrease in total NAR in both groups and abolished the asymmetry in NAR in the healthy subjects (ratio is 1:1 after decongestion). However, significant asymmetry of NAR was still present in the group with acute rhinitis following the administration of decongestant (ratio is 1.5:1 after decongestion). These findings show that the normal asymmetry in NAR was increased during acute rhinitis associated with common cold, and that in healthy subjects (but not in those with rhinitis) the asymmetry was abolished by administration of a topical decongestant. The results are discussed in relation to nasal sympathetic tone and nasal blood flow.     

鼻腔最大吸气流量在临床中的应用

目的 :探讨测量单侧鼻腔最大吸气流量 (PnIFR)的方法及其临床价值。方法 :使用在RHAT 30 1型数字式风速 /温度表基础上研制的流量计测量 10 0例 2 0 0侧麻黄素收缩鼻腔粘膜前、后单侧鼻腔PnIFR。并记录主观感觉鼻腔通气程度。结果 :单侧鼻腔PnIFR值 :男性组正常者明显高于女性组正常者 (P <0 .0 1) ;男性组正常者分别高于男性组轻、中、重度阻塞者 (P <0 .0 1) ;女性组正常者分别高于女性组轻、中、重度阻塞者 (P <0 .0 1) ;两组在麻黄素收缩鼻粘膜前与麻黄素收缩鼻粘膜后 ,差异均有显著性意义 (P <0 .0 1)。主观感觉鼻通气程度 (4级 ) :两组与单侧鼻腔PnIFR值均呈负相关 (P <0 .0 1)。结论 :测量单侧鼻腔PnIFR值可较准确地反映鼻腔通气程度及药物对鼻阻力的影响 ,改装后的热电流量计 ,使用方便 ,测量准确 ,适合于临床研究和日常检查应用     

A systematic review of the nasal index and the significance of the shape and size of the nose in rhinology

Background: There was great interest in the 19th and early 20th century in classifying human races as Caucasian, Asian African etc. according to nasal shape and size, and the nasal index was the most commonly used measurement to differentiate races. Objective of review: To determine if there is any clinical relevance of the shape and size of the nose in relation to physiology, pathology and surgery. Type of review: Systematic review. Search strategy: A structured search of PubMed was performed from 1966 to 2008 for each section of the review focusing on the ethnic variations in nasal index, the effect of climate of nasal shape, ethic variations of nasal physiology and racial predilection for sinonasal pathology. Results: Nasal proportions do vary between ethnic groups but the size and shape of the nose does not define Caucasian, Asian and African races respectively. Anthropologists agree that the nasal variations are due to man’s adaptation to the environment. However, this theory remains to be proven. Published data on nasal physiology have not shown significant differences between the ethnic groups despite obvious differences in nasal proportions. There is no evidence of ethnic specific predilection to disease due to anatomical variation, physiological vulnerability or genetic susceptibility. Rhinology research is often confounded by classifying populations according to race, as racial characteristics are not based on any scientific principles and the nasal index may be a more reliable discriminator. The only area in which the size and shape of the nose is of relevance is in aesthetic and reconstruction surgery. Conclusions: Nasal proportions are important aesthetically but appear to have little relevance to the rhinologist.     

The influence of nasal flow aerodynamics on the nasal physiology

The ability of the human nose to warm and humidify the respiratory air is important to maintaining the internal environment of the lungs, since ambient air is conditioned to nearly alveolar conditions (body temperature and fully saturated with water vapour) upon reaching the nasopharynx. Because of very short time of the inspiratory phase duration, as well as expiratory phase, only the rich vascularization of the nasal mucosa and specific organization of the submucosal vessels are not able to assure such effective physiological activity. Therefore the type of airflow during the respiration is essential to understanding the functional possibilities of the nasal mucosa. Most studies have investigated the airflow only in steady-flow conditions, where the laminar flow was observed. Anatomically accurate physical models of real nasal cavities and particle image velocimetry allow evaluation of the entire flow field in the nasal cavity. In these investigations a partially turbulent flow was observed even at low air velocities in most part of the nasal cavity. From a physiological perspective, a turbulent flow would seem sensible, since it enhances contact between air and the mucosal layer. By doing so, the nasal physiological functions - humidification, cleaning and warming are optimized.     

The importance of side difference in nasal obstruction and rhinomanometry: a retrospective correlation of symptoms and rhinomanometry in 1000 patients

Clin. Otolaryngol. 2012, 37 , 17–22 Objectives: The correlation between subjective and objective outcomes of nasal obstruction is still a matter of controversy. The aim of this study was to determine the minimal level of side difference in nasal airway resistance (NAR measured by Broms’v₂) between the two nasal cavities, which could be discerned subjectively by the patient on a visual analogue scale (VAS). Nasal airway resistance was calculated from rhinomanometric measurements of nasal airflow and transnasal pressure after decongestion of the nasal mucosa. Design: A retrospective study. Setting: ENT department, Vaxjo Central Hospital, Sweden. Participants: We studied 1000 active anterior rhinomanometries from patients with nasal obstructions. Main outcome measures: We compared the side difference of nasal airway resistance with the side difference of VAS estimated immediately prior to the rhinomanometry. Each measurement was performed after nasal decongestion. Results: When the difference in nasal airway resistance between the two nasal cavities was larger than 20° (Broms’v₂) or R₂ > 0.36 Pa/cm³/s, we found a significant correlation between side differences of the objective measurement and the subjective assessment (VAS). With a nasal airway resistance side difference over 20°, an additional 20° difference corresponded to a 0.9 centimetre average VAS change. The more obstructed side of the nose could be determined by VAS in 823 (82.3%) of 1000 patients. Yet, 177 (17.7%) patients had a paradoxical sensation of nasal obstruction with the low resistance side of the nose experienced as the most congested side. Conclusion: A significant correlation between the side differences of nasal airway resistance and VAS can serve as a supplement to rhinoscopy in decisions about nasal surgery. This study also showed that in 17.7% of patients, there was a negative correlation between subjective and objective evaluations of nasal airway resistance. But in this group, the nasal airway resistance side difference was mostly under 20°.