Nasal airway resistance in patients with different degrees of operated unilateral cleft lip: Evaluation of ventilation in 112 patients.

OBJECTIVE: The aim of this study was to compare the nasal airway resistance between the cleft and non-cleft sides in operated unilateral cleft lip (UCL) patients with varying severities at birth, as well as to assess the differences in nasal airway resistance between UCL patients and healthy individuals. METHODS: This retrospective study was conducted on 112 UCL patients who have undergone primary lip reconstructions but not advanced surgeries as the study group and 20 healthy participants as the control group between February 2023 to March 2024. The study group patients were grouped based on the severity of their cleft lip at birth, divided into occult cleft lip group, incomplete cleft lip group, and complete cleft lip group. The anterior rhinomanometry was used to evaluate nasal resistance, including unilateral effective resistances during inspiration (Reffin), expiration (Reffex), and the entire breath (ReffT), as well as unilateral vertex resistance during inspiration (VRin) and expiration (VRex). The Kolmogorov-Smirnov test was used to assess normality. Paired t-tests were utilized to analyze the differences in nasal resistance between the healthy and affected sides within the same group of patients. Student's t-test was used to analyze the differences in nasal resistance among patients with different degrees of cleft lip. A p-value of <0.05 was considered statistically significant. RESULTS: The nasal resistances of the occult cleft and incomplete cleft lip groups showed no significant differences between the cleft and non-cleft sides, and were similar to the control group. However, in the complete cleft lip group, the cleft side nasal resistance was significantly higher than the non-cleft side and control group. Among the groups, the complete cleft lip group had significantly higher nasal resistances on the cleft side for Reffin, VRin, and ReffT compared to the occult cleft group. CONCLUSION: Understanding the nasal resistance of different degrees of operated UCL patients can benefit clinical diagnosis and treatment. Patients with complete cleft lip have more severe nasal obstruction on the cleft side, with greater impact on inhalation than exhalation. For these patients, treatment by an otolaryngologist is recommended to improve nasal airflow.

Rhinomanometry: A Comprehensive Review of Its Applications and Advancements in Rhinology Practice.

Rhinomanometry is a pivotal diagnostic technique in rhinology, providing a quantitative assessment of nasal airflow and resistance. This review comprehensively examines the historical development, principles and clinical applications of rhinomanometry, emphasising its role in diagnosing nasal obstructions, preoperative evaluations and monitoring therapeutic outcomes. Recent advancements, including the integration with imaging technologies and the application of artificial intelligence (AI), have significantly enhanced the accuracy and utility of rhinomanometry. Despite facing challenges such as technical limitations and the need for standardisation, rhinomanometry remains an invaluable tool in both clinical and research settings. The review also explores future directions, highlighting the potential for device miniaturisation, telemedicine integration, personalised protocols and collaborative research efforts. These advancements will likely expand the accessibility, accuracy and clinical relevance of rhinomanometry, solidifying its importance in the ongoing evolution of rhinology practice.

Nasal resistance and inflammation: mechanisms for obstructive sleep apnea from chronic rhinosinusitis.

STUDY OBJECTIVES: We have previously estimated that the prevalence of obstructive sleep apnea (OSA) among World Trade Center (WTC) rescue and recovery workers is 75% and identified that having symptoms of chronic rhinosinusitis (CRS) is an independent risk factor for OSA in this population. Nasal inflammation and/or elevated awake nasal resistance that carried over into sleep could explain this association. To understand the mechanism(s) for the elevated risk of OSA observed in WTC responders with chronic rhinosinusitis (CRS) symptoms we examined if elevated awake supine nasal resistance was associated with OSA, CRS and/or nasal inflammatory biomarkers. METHODS: 601 individuals (83% male, average age 53 years, BMI=29.9 ± 5.5 kg/m2) enrolled in the WTC Health Program and without significant pre-9/11 snoring, underwent two nights of home sleep apnea testing, measurements of anterior rhinomanometry in the supine position, and nasal lavage. RESULTS: Awake supine nasal resistance was not associated with OSA; 74.8% and 74.4% of the participants with low and high nasal resistance respectively, had OSA (P=NS). Patients with CRS had elevated nasal inflammatory markers (IL6, IL8, ECP and Neut) but did not have high nasal resistance. Nasal inflammatory markers were not correlated with nasal resistance. CONCLUSIONS: As awake nasal resistance did not explain the relationship of CRS to OSA in this large and well characterized dataset, our findings suggest that either "sleep" nasal resistance or other factors such as increased supraglottic inflammation, perhaps through impairing upper airway reflex mechanisms, or systemic inflammation are involved in the pathophysiology of OSA in the WTC population.

Numerical simulation of the influence of nasal cycle on nasal airflow.

To study the characteristics of nasal airflow in the presence of nasal cycle by computational fluid dynamics. CT scan data of a healthy Chinese individual was used to construct a three-dimensional model of the nasal cavity to be used as simulation domain. A sinusoidal airflow velocity is set at the nasal cavity entrance to reproduce the breathing pattern of a healthy human. There was a significant difference in the cross-sectional area between the two sides of the nasal cavity. Particularly, the decongested side is characterized by a larger cross-section area, and consequently, by a larger volume with respect to the congested side. The airflow velocity, pressure, and nasal resistance were higher on the congested narrow side. The temperature regulation ability on the congested narrow side was stronger than that on the decongested wider side. During the nasal cycle, there are differences in the nasal cavity function between the congested and decongested sides. Therefore, when evaluating the impact of various factors on nasal cavity function, the nasal cycle should be considered.

Nasal Patency Across Seated, Supine, and Recumbent Postures in Individuals With and Without Allergic Rhinitis.

Objectives: This study aimed to investigate the effects of seated, supine, and recumbent postures on nasal resistance in individuals with allergic rhinitis (AR) and healthy controls, which has not been investigated in the past. Methods: A visual analog scale (VAS) assessed subjective nasal obstruction, while acoustic rhinometry and video endoscopy provided objective measures. Sixty participants, comprising 30 AR patients and 30 healthy controls, were evaluated across 4 postures without decongestion: seated, supine, left recumbent, and right recumbent. Results: In patients with AR, we noted no significant changes in subjective nasal blockage under various postures (all P > .18). However, significant reductions of minimal cross-sectional area (mCSA) were found (seated vs supine, P = .014; seated vs left recumbent, P = .001; seated vs right recumbent, P < .001) and significant increases in the inferior turbinate hypertrophy were observed on the dependent side of the nose when in recumbent posture (right nose: seated vs right recumbent, P = .013; left nose: seated vs left recumbent, P = .003). On the contrary, healthy controls experienced increased subjective nasal obstruction (VAS scores: seated vs supine, P < .001; seated vs left recumbent, P = .003; seated vs right recumbent, P < .001), reductions in mCSA (seated vs supine, P = .002; seated vs right or left recumbent, both P = .001), and increased inferior turbinate hypertrophy on the dependent side of the nose (right nose: seated vs right recumbent, P = .003; left nose: seated vs left recumbent, P = .006). Conclusions: Healthy controls reported better nasal patency when shifting from supine or recumbent to more upright or less gravity-dependent seated postures, which was further supported by objective examinations. On the contrary, despite patients with AR not subjectively perceiving increased nasal patency while adopting more upright postures, objective evaluations demonstrated an improvement in their nasal airflow in these less gravity-dependent postures.Level of Evidence: 4.

Assessing nasal airway resistance and symmetry: An approach to global perspective through computational fluid dynamics.

This study aimed to explore the variability in nasal airflow patterns among different sexes and populations using computational fluid dynamics (CFD). We focused on evaluating the universality and applicability of dimensionless parameters R (bilateral nasal resistance) and ϕ (nasal flow asymmetry), initially established in a Caucasian Spanish cohort, across a broader spectrum of human populations to assess normal breathing function in healthy airways. In this retrospective study, CT scans from Cambodia (20 males, 20 females), Russia (20 males, 18 females), and Spain (19 males, 19 females) were analyzed. A standardized CFD workflow was implemented to calculate R-ϕ parameters from these scans. Statistical analyses were conducted to assess and compare these parameters across different sexes and populations, emphasizing their distribution and variances. Our results indicated no significant sex-based differences in the R parameter across the populations. However, moderate sexual dimorphism in the ϕ parameter was observed in the Cambodian group. Notably, no geographical differences were found in either R or ϕ parameters, suggesting consistent nasal airflow characteristics across the diverse human groups studied. The study also emphasized the importance of using dimensionless variables to effectively analyze the relationships between form and function in nasal airflow. The observed consistency of R-ϕ parameters across various populations highlights their potential as reliable indicators in both medical practice and further CFD research, particularly in diverse human populations. Our findings suggest the potential applicability of dimensionless CFD parameters in analyzing nasal airflow, highlighting their utility across diverse demographic and geographic contexts. This research advances our understanding of nasal airflow dynamics and underscores the need for additional studies to validate these parameters in broader population cohorts. The approach of employing dimensionless parameters paves the way for future research that eliminates confounding size effects, enabling more accurate comparisons across different populations and sexes. The implications of this study are significant for the advancement of personalized medicine and the development of diagnostic tools that accommodate individual variations in nasal airflow.

Effects of Mucosal Decongestion on Nasal Aerodynamics: A Pilot Study.

OBJECTIVE: Mucosal decongestion with nasal sprays is a common treatment for nasal airway obstruction. However, the impact of mucosal decongestion on nasal aerodynamics and the physiological mechanism of nasal airflow sensation are incompletely understood. The objective of this study is to compare nasal airflow patterns in nasal airway obstruction (NAO) patients with and without mucosal decongestion and nondecongested healthy subjects. STUDY DESIGN: Cross-sectional study of a convenience sample. SETTING: Academic tertiary medical center. METHODS: Forty-five subjects were studied (15 nondecongested healthy subjects, 15 nondecongested NAO patients, and 15 decongested NAO patients). Three-dimensional models of the nasal anatomy were created from computed tomography scans. Steady-state simulations of airflow and heat transfer were conducted at 15 L/min inhalation rate using computational fluid dynamics. RESULTS: In the narrow side of the nose, unilateral nasal resistance was similar in decongested NAO patients and nondecongested healthy subjects, but substantially higher in nondecongested NAO patients. The vertical airflow distribution within the nasal cavity (inferior vs middle vs superior) was also similar in decongested NAO patients and nondecongested healthy subjects, but nondecongested NAO patients had substantially less middle airflow. Mucosal cooling, quantified by the surface area where heat flux exceeds 50 W/m2, was significantly higher in decongested NAO patients than in nondecongested NAO patients. CONCLUSION: This pilot study suggests that mucosal decongestion improves objective measures of nasal airflow, which is consistent with improved subjective sensation of nasal patency after decongestion.

Computational Rhinology: Unraveling Discrepancies between In Silico and In Vivo Nasal Airflow Assessments for Enhanced Clinical Decision Support.

Computational rhinology is a specialized branch of biomechanics leveraging engineering techniques for mathematical modelling and simulation to complement the medical field of rhinology. Computational rhinology has already contributed significantly to advancing our understanding of the nasal function, including airflow patterns, mucosal cooling, particle deposition, and drug delivery, and is foreseen as a crucial element in, e.g., the development of virtual surgery as a clinical, patient-specific decision support tool. The current paper delves into the field of computational rhinology from a nasal airflow perspective, highlighting the use of computational fluid dynamics to enhance diagnostics and treatment of breathing disorders. This paper consists of three distinct parts-an introduction to and review of the field of computational rhinology, a review of the published literature on in vitro and in silico studies of nasal airflow, and the presentation and analysis of previously unpublished high-fidelity CFD simulation data of in silico rhinomanometry. While the two first parts of this paper summarize the current status and challenges in the application of computational tools in rhinology, the last part addresses the gross disagreement commonly observed when comparing in silico and in vivo rhinomanometry results. It is concluded that this discrepancy cannot readily be explained by CFD model deficiencies caused by poor choice of turbulence model, insufficient spatial or temporal resolution, or neglecting transient effects. Hence, alternative explanations such as nasal cavity compliance or drag effects due to nasal hair should be investigated.

Assessing Nasal Epithelial Dynamics: Impact of the Natural Nasal Cycle on Intranasal Spray Deposition.

This study investigated the intricate dynamics of intranasal spray deposition within nasal models, considering variations in head orientation and stages of the nasal cycle. Employing controlled delivery conditions, we compared the deposition patterns of saline nasal sprays in models representing congestion (N1), normal (N0), and decongestion (P1, P2) during one nasal cycle. The results highlighted the impact of the nasal cycle on spray distribution, with congestion leading to confined deposition and decongestion allowing for broader dispersion of spray droplets and increased sedimentation towards the posterior turbinate. In particular, the progressive nasal dilation from N1 to P2 decreased the spray deposition in the middle turbinate. The head angle, in conjunction with the nasal cycle, significantly influenced the nasal spray deposition distribution, affecting targeted drug delivery within the nasal cavity. Despite controlled parameters, a notable variance in deposition was observed, emphasizing the complex interplay of gravity, flow shear, nasal cycle, and nasal morphology. The magnitude of variance increased as the head tilt angle increased backward from upright to 22.5° to 45° due to increasing gravity and liquid film destabilization, especially under decongestion conditions (P1, P2). This study's findings underscore the importance of considering both natural physiological variations and head orientation in optimizing intranasal drug delivery.

On the comparison between pre- and post-surgery nasal anatomies via computational fluid dynamics.

Nasal breathing difficulties (NBD) are widespread and difficult to diagnose; the failure rate of their surgical corrections is high. Computational fluid dynamics (CFD) enables diagnosis of NBD and surgery planning, by comparing a pre-operative (pre-op) situation with the outcome of virtual surgery (post-op). An equivalent comparison is involved when considering distinct anatomies in the search for the functionally normal nose. Currently, this comparison is carried out in more than one way, under the implicit assumption that results are unchanged, which reflects our limited understanding of the driver of the respiratory function. The study describes how to set up a meaningful comparison. A pre-op anatomy, derived via segmentation from a CT scan, is compared with a post-op anatomy obtained via virtual surgery. State-of-the-art numerical simulations for a steady inspiration carry out the comparison under three types of global constraints, derived from the field of turbulent flow control: a constant pressure drop (CPG) between external ambient and throat, a constant flow rate (CFR) through the airways and a constant power input (CPI) from the lungs can be enforced. A significant difference in the quantities of interest is observed depending on the type of comparison. Global quantities (flow rate, pressure drop and nasal resistance) as well as local ones are affected. The type of flow forcing affects the outcome of the comparison between pre-op and post-op anatomies. Among the three available options, we argue that CPG is the least adequate. Arguments favouring either CFR or CPI are presented.

Role of Nasal Ventilation Function in Obstructive Sleep Apnea Syndrome in Children.

Background: The association between increased nasal resistance (NR) and obstructive sleep apnea syndrome (OSAS) is controversial. The purpose of this study was to examine nasal ventilation function (NVF) in children with OSAS, with a focus on its pathogenetic role. Methods: Children were recruited and divided into the OSAS group (n = 109) and control group (n = 116). The participants underwent polysomnography (PSG), measurement of NR, and acoustic rhinometry (AR). A combination of intranasal corticosteroids (ICS) and oral montelukast (OM) was administered to 90 children with mild to moderate OSAS for 12 weeks. After excluding participants who dropped out or were lost to follow-up, there were 58 children who responded to the treatment, who were divided into 2 groups-A and B. We compared the size of the tonsil adenoids, the PSG, NR, and AR before and after treatment in the 2 groups. Results: Children aged 6 to 12 years with OSAS had significantly higher NR than the control group (P < .05). The OSAS group had a smaller nasal minimal cross-sectional area (NMCA), nasal cavity volume (NCV) from 0 to 5 cm, and nasopharyngeal volume (NPV) from 6 to 8 cm than the control group, and the difference was statistically significant (P < .05 or P < .01). A total of 58 (84.1%) children responded to the 12-week ICS+OM treatment and 11 (15.9%) children did not respond to the treatment. Effective treatment was achieved in 32 children, as evidenced by a significant reduction in tonsil adenoid size and variations in NR and AR values. There were significant improvements in NR, NMCA, and NCV in the remaining 26 children who were successfully treated, but there was no change in tonsil adenoids and NPV value. Conclusion: NVF may play an important pathogenetic role in children with OSAS.

Horseshoe osteotomy maintains the nasal cavity and function after superior repositioning.

The aim of this prospective cohort study was to compare changes in nasal cavity and function between Le Fort I with and without horseshoe osteotomy after superior repositioning of the maxilla. The patients were divided into 2 groups, a Le Fort I alone (LF alone) group and a combination Le Fort I and horseshoe osteotomy (HS) group. The nasal cavity volume was measured using 3-dimensional computed tomographic images, and nasal resistance was assessed by anterior active mask rhinomanometry. The HS group consisted of 17 patients, and the LF alone group consisted of 15 patients. The magnitude of change in nasal cavity volume was significantly smaller in the HS group than in the LF alone group (p < 0.001), even though the mean amount of superior maxillary movement was considerably larger in the HS group than in the LF alone group (p < 0.001). Mean nasal resistance was significantly smaller postoperatively than preoperatively in the HS group (p < 0.05). Furthermore, the change in nasal resistance was smaller in the HS group than in the LF alone group (p < 0.001). Within the limitations of this study, it seems that horseshoe osteotomy is useful for maintaining the nasal cavity and function after superior repositioning of the maxilla.

Nasal patency and mandibular movement: clinical application in prosthodontics.

This case report describes a patient with a primary concern of persistent mandibular deviation during speech who experienced clinically significant improvement (mandibular movement without deviation) after improvements to nasal resistance. At the initial consultation, temporary placement of a nasal valve dilator immediately eliminated the patient's mandibular deviation during speech, indicating the need for referral to an otolaryngologist. The patient was also provided with a dental appliance to address secondary concerns of temporomandibular joint noises and cervicofacial pain. Although the dental treatment provided some relief, resolution of the patient's mandibular deviation during speech did not occur until after nasal surgery was completed. This case illustrates the importance and effects of nasal resistance and nasal patency to obtaining a reproducible mandibular position.

[Effect of nasal swell body on nasal airflow and Artemisia pollen deposition].

Objective:The nasal swell body（NSB） consists of the nasal septal cartilage, nasal bone, and swollen soft tissue, all of which are visible during endoscopic and imaging examinations. Although the function of the NSB remains uncertain, there is evidence to suggest that it plays a vital role in regulating nasal airflow and filtering inhaled air. Based on anatomical and histological evidence, it is hypothesized that the NSB is indispensable in these processes. This study aims to investigate the impact of NSB on nasal aerodynamics and the deposition of allergen particles under physiological conditions. Methods:The three-dimensional （3D） nasal models were reconstructed from computed tomography （CT） scans of the paranasal sinus and nasal cavity in 30 healthy adult volunteers from Northwest China, providing basis for the construction of models without NSB following virtual NSB-removal surgery. To analyze the distribution of airflow in the nasal cavity, nasal resistance, heating and humidification efficiency, and pollen particle deposition rate at various anatomical sites, we employed the computed fluid dynamics（CFD） method for numerical simulation and quantitative analysis. In addition, we created fully transparent segmented nasal cavity models through 3D printing, which were used to conduct bionic experiments to measure nasal resistance and allergen particle deposition. Results:①The average width and length of the NSB in healthy adults in Northwest China were （12.85±1.74） mm and （28.30±1.92） mm, respectively. ②After NSB removal, there was no significant change in total nasal resistance, and cross-sectional airflow velocity remained essentially unaltered except for a decrease in topical airflow velocity in the NSB plane. ③There was no discernible difference in the nasal heating and humidification function following the removal of the NSB; ④After NSB removal, the deposition fraction（DF） of Artemisia pollen in the nasal septum decreased, and the DFs post-and pre-NSB removal were（22.79±6.61）% vs （30.70±12.27）%, respectively; the DF in the lower airway increased, and the DFs post-and pre-NSB removal were（24.12±6.59）% vs （17.00±5.57）%, respectively. Conclusion:This study is the first to explore the effects of NSB on nasal airflow, heating and humidification, and allergen particle deposition in a healthy population. After NSB removal from the healthy nasal cavities: ①nasal airflow distribution was mildly altered while nasal resistance showed no significantly changed; ②nasal heating and humidification were not significantly changed; ③the nasal septum's ability to filter out Artemisia pollen was diminished, which could lead to increased deposition of Artemisia pollen in the lower airway.

Correlational Analysis of Nasal Resistance and Acoustic Rhinometry Measurements With the Localization of Fungus Balls in the Paranasal Sinuses.

Objective: To investigate the reason for fungal balls (FBs) being localized in paranasal sinuses, we analyzed the clinical presentations of patients with FB rhinosinusitis (FBS). Methods: Clinical data, anatomical variation (ie, nasal septal deviation, concha bullosa, and Haller cell), as well as measurements of nasal resistance (NR), nasal cavity volume (NCV), and nasal cross-sectional area (NCA) using active anterior rhinomanometry and acoustic rhinometry were collected from FBS patients hospitalized in our hospital between January 2021 and December 2022. A retrospective analysis was conducted using IBM SPSS 19.0 to perform the Shapiro-Wilk test, t-test and logistic regression analysis. Results: A total of 95 FBS patients, including 33 male and 62 female patients, were included in this study. FBs in maxillary sinus were the most common (83, 87.4%), followed by sphenoid sinus (9, 9.5%). Logistic multivariate regression analysis revealed that a higher left-to-right NR ratio was associated with an increased likelihood of FBs being present in the left sinus [Odds ratios (OR) = 0.185; 95% CI, 0.061-0.558; P < .01]. When the ratio of the left-to-right second-minimum NCA was higher and the FB was more in the right sinus (OR = 3.194; 95% CI, 1.593-6.405; P = .001). Additionally, when the difference between left and right NCV was greater and FB occurred more commonly in the right sinus (OR = 1.435; 95% CI, 1.196-1.721; P < .001). Nonetheless, the presence of nasal septum deviation and concha bullosa did not significantly contribute to FB formation. Conclusions and significance: The differences in NR, NCA, and NCV between the affected and unaffected sides of nasal cavity are risk factors for the FB formation. To reduce FBS recurrence, it is important to focus on improving nasal ventilation during the surgical treatment.

[Analysis of related factors for postoperative recurrence of antrochoanal polyps in children].

Objective:To analyze the correlation between nasal resistance and lung function in children with allergic rhinitis（AR）, and explore whether AR children with increased nasal resistance are accompanied by potential lower respiratory tract involvement. Methods:A total of 88 children diagnosed with AR from December 2021 to December 2022 were selected as the study group, while 20 normal children were selected as the control group during the same period. Both the study group and the control group children underwent lung function tests, bronchodilator tests, and nasal resistance measurements. Spearman correlation analysis and multiple linear regression analysis were performed on the results of nasal resistance and lung function tests to explore the relationship and influencing factors between the two groups.According to the results of nasal resistance measurement, children with increased nasal resistance and abnormal lung function were divided into a mild increase in nasal resistance with abnormal lung function group and a moderate to severe increase in nasal resistance with abnormal lung function group. The degree of increased nasal resistance was analyzed to determine whether it would affect lung function. Results:The FEF25, FEF50, and FEF75 levels in the study group were significantly lower than those in the control group（P<0.05）. The FEV1of children with moderate to severe increase in AR nasal resistance was significantly lower than that of children with mild increase in AR nasal resistance（P<0.05）. There was a correlation between nasal resistance and FEV1/FVC, R20 in AR children, and FEV1/FVC, R20 were the influencing factors of nasal resistance in AR children（P<0.05）. There was no correlation between total serum IgE, lung function, and bronchodilation test in AR patients（P>0.05）. Conclusion:The nasal ventilation function of AR patients has changed, and there is a downward trend in small airway function. Children with moderate to severe increase in AR nasal resistance have a more significant decrease in lung ventilation function than those with mild increase. The nasal resistance of AR children is influenced by FEV1/FVC and R20, and FEV1/FVC and R20 decrease as the nasal resistance value increases. The improvement rate of lung function and FEV1 are not influencing factors for the elevation of total serum IgE.

Association Between Anterior Rhinoscopic/Endoscopic Assessment of Internal Nasal Valve and Various Nasal Deformities in the Rural Population of Vidarbha Region of India: A Cross-Sectional Study.

Background The nasal valves constitute the majority of the nasal cavity's resistance. Any reduction in this already narrow area can cause a significant reduction in the nasal airflow. In this present study, the aim was to do an endoscopic assessment of the internal nasal valve (INV) in patients with various nasal septal deviations, with or without external nasal deformity. We measured endoscopically the INV in various nasal deformities and derived its association with the INV on anterior rhinoscopy and endoscopic assessment. Method  We included 75 patients in the study who were analyzed for angle and grade of the INV by anterior rhinoscopic examination and Hopkins rod zero-degree nasal endoscope (Karl Storz SE & Co., Tuttlingen, Germany). Nasal septal deviations were also studied with respect to the Mladina classification. Correlation between various nasal septal deviations with the INV was done. Since studies addressing the classification of INV are not available in the literature, for the purpose of simplification of observation of INV angle, (normal range 9-15 degrees), subjective stratification was made in the study, i.e. below 9, 9-15, and more than 15 degrees for the sake of knowing the underlying cause and its relationship. Result An anterior rhinoscopic examination was performed on 75 patients. INV Grade 1 was the most common, with 18 patients of (69.2%), 15 patients of DNS with caudal dislocation (55.6%), five patients of DNS with spur (38.5%), and four patients of DNS with external nasal deformity (50%). The next frequently observed Grade of INV on anterior rhinoscopy examination was Grade 2, in 11 patients of DNS with caudal dislocation (40.7%), four patients of DNS with spur (30.8%), and three patients of DNS with external deformity (37.5%), which was statistically significant in our study. In the majority of patients with all types of nasal septal deviations with or without external nasal deformity, INV (angle) of less than 9 degrees was noted, which was statistically significant. A linear relationship, ie., Grade 0 INV in Type I, Grade 1 INV in types II, III, IV, and V, and Grade 2 in Type VII was observed. Our study is on par with the literature questioning the dogma of the normal angle of INV being 9-15 degrees. Conclusion We were able to establish a positive and complimentary role of anterior rhinoscopic and endoscopic assessment of INV. The proposed novel classification of the angle of INV by endoscopic assessment gives a better insight into the association of INV with various nasal septal deformities with or without external nasal septal deviation.

Reliability of parental reporting of child snoring in children referred for obstructive sleep apnea.

Despite the high number of studies based on subjective reports of snoring, self-reported snoring has hardly been validated at all. As there is no "gold-standard" for objective snoring measurements, studies must evaluate whether the presence of snoring based on parental judgement is linked to objective measurements of nasal and/or pharyngeal obstruction in children referred for obstructive sleep apnea. A total of 146 children (median age 11 years) underwent polysomnography (with snoring recording using nasal cannula signal), acoustic rhinometry and pharyngometry, while their parents filled out the Spruyt-Gozal questionnaire assessing both frequency and loudness of subjective snoring. Three categories were further differentiated (null, low and high) for both frequency and loudness. The apnea-hypopnea index was significantly different in the three groups for both frequency (p = 0.04) and loudness (p = 0.01) of subjective snoring. Children in the low or high groups (frequency or loudness), compared with those in the null group, experienced a decline in both pharyngeal (sitting and supine positions) and nasopharyngeal (supine position) volumes (frequency, pharynx sitting: p = 0.03; supine: 0.005 and nasopharynx: p = 0.002; loudness, p = 0.03; p = 0.007 and p = 0.03; three group comparisons). Objective snoring frequency during the night obtained with cannula was weakly related to loudness of subjective snoring but not to subjective snoring frequency during the week, and was biased by nasal obstruction. In conclusion, our study showed that parental assessment of snoring is related to a reduction in both pharyngeal and nasopharyngeal volumes in snorers, arguing for the adequacy of their evaluation of both snoring frequency and loudness.

Effects of Supine and Prone Positions on Nasal Patency in Healthy Individuals.

OBJECTIVES: Supine position reduces nasal patency compared with that in the sitting position; however, data on the effects of prone position on nasal patency is lacking. METHODS: We assessed the nasal patency of 30 healthy individuals without upper respiratory tract disorders by using visual analog scale (VAS) score and acoustic rhinometry in 7 positions: sitting; frontal, right, and left supine; and frontal, right, and left prone. RESULTS: According to the VAS scores, compared with that in the sitting position, both the supine and prone positions significantly increased subjective nasal obstruction (P < .001). The prone position had a more significant effect than did the supine position (P = .017). The results of minimal cross-sectional area measured through acoustic rhinometry demonstrated that both the supine and prone positions reduced the nasal patency significantly, but without significant differences between the effects of prone and supine positions (P = .794). CONCLUSION: This is the first study to elucidate that the prone position can significantly reduce the nasal patency in healthy individuals through subjective and objective assessments. LEVEL OF EVIDENCE: IV.

Influence of postural changes on nasal resistance in patients with obstructive sleep apnea.

OBJECTIVE: Increased nasal resistance (NR) can augment upper airway collapse in patients with obstructive sleep apnea (OSA). Posture change can lead to altered nasal resistance. Our study aimed to investigate the influence of posture changes on NR in patients with OSA. METHODS: Healthy controls without subjective nasal obstruction (apnea-hypopnea index (AHI) < 5 events/h), patients with OSA and subjective nasal obstruction, and patients with OSA and no subjective nasal obstruction were recruited. NR was measured by active anterior rhinomanometry in sitting, supine, left-lateral, and right-lateral postural positions. Total NR and postural change-related NR increments were calculated and compared among groups. RESULTS: In total, 26 healthy controls and 72 patients with OSA (mean AHI 39.7 ± 24.8 events/h) were recruited. Of patients with OSA, 38/72 (53%) had subjective nasal obstruction. Compared with controls, patients with OSA and no subjective nasal obstruction had lower total NR (inspiration, p = 0.037; expiration, p = 0.020) in the supine postural position. There was no difference in sitting, left-lateral, and right-lateral total NR among groups. Total NR was higher in lateral compared to sitting posture in both patients with OSA and in controls. The NR increment for sitting to supine postural change was significantly lower in patients with OSA (inspiration, p = 0.003; expiration, p = 0.005) compared with controls. The change in NR showed no statistically significant difference among groups in supine-left or supine-right postural change. CONCLUSION: Patients with OSA had lower supine total NR and lower total NR increment in the sitting to supine postural change, which may be related to a different posture-related NR regulatory mechanism. This study provides a new exploratory direction for the compensatory mechanism of the upper airway to collapse during sleep.