Nasal Airflow Research Articles

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.

Task-Dependent Velopharyngeal Timing in Singers with Classical Training

This study examined velopharyngeal (VP) timing characteristics during singing and speaking tasks among singers with varying degrees of classical training. Pressure-flow data were collected when eight soprano singers sang and spoke the phrase, "I will say hamper," at different pitch (C4 and C5) and loudness levels (soft, medium, and loud). VP aerodynamic variables (VP gap, peak nasal airflow [NF], and peak intraoral pressure [OP]) and timing variables (NF pulse duration, OP pulse duration, and total duration of the /mp/ sequence) were of particular interest. Results of linear mixed-effects models showed no significant main effect of task type (speaking vs. singing) on VP aerodynamic variables. Task type was found to have a statistically significant main effect on OP pulse duration (F(1, 77) =27.590, P<0.05) and total duration of the /mp/ sequence (F(1, 75.034) =17.895, P<0.05), with both durational measures significantly shorter for singing (OP pulse duration: 200ms, total duration of the /mp/ sequence: 212ms) than for speaking (OP pulse duration: 228ms, total duration of the /mp/ sequence: 238ms). The pitch had a significant main effect on OP pulse duration, with C5 (207ms) significantly shorter than C4 (221ms). Loudness was found to have no significant main effects on any of the VP timing variables. VP timing patterns significantly differed between the singing and the speaking task. Specifically, the singers employed a quick OP pulse rise time, which shortened OP pulse duration as well as the total duration of the /mp/ sequence during the singing task in comparison to the speaking task. Robust VP timing patterns observed during singing may reflect the singers' skilled control of the VP mechanism to achieve functional and esthetic goals.

Variations of olfactory function with circadian timing and chronotype.

Cumulative animal studies have suggested that olfaction can be regulated by circadian clock. However, human studies on the topic are relatively limited. The present study thus aimed to investigate diurnal variation in olfaction in healthy adults while examining potential modulating factors. We conducted four rounds of testing on 56 healthy adults (32 women) aged 31 ± 12 years, throughout a single day, during morning (8:00-10:00 h), noon (12:00-14:00 h), afternoon (16:00-18:00 h), and evening (20:00-22:00 h). At the first appointment, participants completed full olfactory function testing using the Sniffin’ Sticks, questionnaires on medical history, nasal symptoms, sleep quality, and chronotype, and were assessed for blood pressure, heart rate, peak nasal inspiratory flow (PNIF), attention level, and rated their smell ability, nasal patency, wakefulness, and concentration level using visual analog scale (VAS) ratings. Subsequent appointments measured olfactory threshold, attentional level, PNIF, blood pressure, heart rate and VAS ratings repeatedly. Olfactory threshold (OT) scores varied significantly between different times of the day, with the highest score in the evening and the lowest in the morning. Similar differences were also observed in PNIF, with the highest value in the evening and the lowest in the morning. However, there were no significant correlations between OT score and PNIF across all four-time testing, as well as between differences in [OT evening â€" OT morning] and [PNIF evening â€" PNIF morning]. Furthermore, a generalized linear mixed model indicated that the testing time of the morning, evening chronotype, self-reported body mass index (BMI), rated smell ability, and rated nasal patency significantly predicted the Sniffin' Sticks OT score. Olfactory function fluctuates throughout the waking hours of the day, with the highest olfactory sensitivity observed in the evening and the lowest in the morning. This pattern is also seen in nasal patency. However, it appears that the circadian changes of nasal airflow may not significantly depend on the circadian changes of the olfactory sensitivity. In addition, chronotype and BMI may regulate such olfactory-circadian variation. These findings provide important insights for future research on the accurate diagnosis and treatment of olfactory dysfunction.

Effectiveness of Uvulopalatoplasty and Nasal Surgery in OSAS Patients.

This study aims to evaluate the effectiveness of simultaneous uvulopalatoplasty and nasal surgery in patients with moderate obstructive sleep apnoea syndrome. We studied 48 patients with obstructive sleep apnoea syndrome and nasal breathing disorders. The 1st group of 20 patients underwent septoplasty and volumetric tissue reduction of inferior turbinates and the 2nd group of 28 patients underwent septoplasty, volumetric tissue reduction of inferior turbinate, uvulopalatoplasty. In the 1st group, the pre-operative apnoea-hypopnea index median decreased from 22.1 ep/h to 14.9 ep/h after the surgery. Pre-operative median of nasal airflow volume grew from 167.0 cm3 to 609.5 cm3 post-operatively and the loudness of snoring decreased from 2.7±0.2 to 0.7±0.2. In the 2nd group, the apnoea-hypopnea index median decreased from 20.4 ep/h to 5.3 ep./h. The pre-operative median of nasal airflow volume grew from 189.5 cm3 to 519.5 cm3 post-operatively and the loudness of snoring improved from 2.6±0.2 pre-op to 1.1±0.2. Patients with moderate obstructive sleep apnoea syndrome and nasal breathing disorders are advised to have nasal surgery combined with uvulopalatoplasty for a better outcome.

Facial Pain Triggered by Inferior Turbinate Partial Resection in a Patient with a Previous History of Inferior Meatal Antrostomy: A Case Report.

Inferior meatal antrostomy (IMA) is regarded as a safe method, with minimal complications, for managing various lesions in the maxillary sinus. However, in patients with persisting IMA window, resection of the inferior turbinate may result in direct airflow into the antrum, irritating the antral mucosa. Case report and review of literature. The present report describes a 29-year-old man who previously underwent unilateral IMA for the excision of a dentigerous cyst. The patient did not report any facial pain following the excision of the cyst. One year later, this patient underwent partial resection of the inferior turbinate for the resolution of nasal stuffiness by another surgeon. Soon after surgery, the patient developed severe facial and ocular pain on the side of the IMA, with the pain being especially aggravated upon inhalation. Endoscopy and computed tomography (CT) revealed a persisting IMA window. The patient's severe discomfort was thought to result from direct airflow into the maxillary sinus, as the resected turbinate may have altered normal nasal airflow. A unilateral inferior meatal augmentation procedure (IMAP) with an autologous ear cartilage implant was performed, resulting in complete relief of pain and discomfort. Although IMA alone is a relatively safe surgical procedure, care should be taken when performing inferior turbinoplasty in patients with persistent IMA opening.

Subcutaneous Immunotherapy (SCIT) with the New Polymerized Molecular Allergoid Alt a1: A Pilot Study in Children with Allergic Rhinitis Sensitized to Alternaria Alternata

Background: We followed the effects of a new SCIT with a chemically polymerized allergen Alt a1, evaluating the trend of clinical and functional parameters in an observational-prospective study. Methods: 42 children with AR and intermittent asthma sensitized to A.A.: 17 patients started SCIT (Modigoid®), and 25 continued symptomatic therapy. At the initial visit (T0), all patients performed total IgE (tIgE) and specific IgE (sIgE) for Alt a1, nasal nitric oxide (nFeNo), nasal cytology, anterior active rhinomanometry (AAR) and spirometry. After 24 months (T1), they repeated the same procedures as in T0. Results: Patients treated with Modigoid presented a statistically significant (p &lt; 0.001) reduction of nFeNO (T0:1651.06 ± 149.18; T1: 1394.12 ± 108.98), tIgE (T0: 311.48 ± 144.18; T1: 164.73 ± 50.69), sIgE for Alt a1 (T0: 28.59 ± 12.69; T1: 19.54 ± 7.37), an improvement of nasal airflow (T0: 71.62 ± 8.66; T1: 95.12 ± 5.91), nasal eosinophils (T0: 20.59 ± 2.35; T1: 14.88 ± 1.65) and FEV1 (T0: 95.58 ± 7.91; T1: 116.64 ± 5.94). Conclusions: The new SCIT for Alt a1 significantly improves AR symptoms from a subjective, objective point of view and laboratory and functional parameters.

Computational fluid dynamics calculations in inferior turbinate surgery: a cohort study

PurposeTo investigate how the results of nasal computational fluid dynamics (CFD) simulations change due to inferior turbinate surgery and how the results correlate with patient specific subjective assessment and volumetric results in the nasal cavities.MethodsThe steady inspiratory airflow of 25 patients was studied pre- and postoperatively with heat transfer from the mucous membrane by performing CFD calculations to patient-specific nasal cone beam computed tomography images. These results were then compared to the severity of the patients’ nasal obstruction Visual Analogue Scale (VAS) and Glasgow Health Status Inventory assessments, and acoustic rhinometry measurements.ResultsTotal wall shear forces decreased statistically significantly (p < 0.01) in the operated parts of the inferior turbinates. Patients’ subjective nasal obstruction VAS assessment changes between the pre- and postoperative conditions correlated statistically significantly (p = 0.04) with the wall shear force results.ConclusionInferior turbinate surgery lead to decreased total wall shear force values postoperatively. Changes in subjective nasal obstruction VAS results against total wall shear force changes between the pre- and postoperative conditions were statistically significant. CFD data have a potential to be used for the evaluation of nasal airflow.

Diseases of the upper respiratory tract and their pathogenetic mechanisms in children living under conditions of chronic exposure to aldehydes and aromatic hydrocarbons

Introduction. The problem of diseases of the respiratory system in children in regions with technogenic atmospheric pollution by chemical agents is relevant. &#x0D; The aim of the study was to study the features of the formation of the pathology of the upper respiratory tract, their pathogenetic mechanisms, and causal relationships of clinical, instrumental, and immunological disorders with toxic load in children living under conditions of chronic exposure to phenols and aromatic hydrocarbons of the industrial origin. &#x0D; Materials and methods. one thousand one hundred fifty one 4–13 years children were examined, 883 people made up the observation group and lived in the territory with excess of hygienic standards in the air of phenol, formaldehyde, acrolein, o-xylene. The comparison group consisted of 268 children living in the territory of ecological well-being. The prevalence of pathology of the upper respiratory tract (URT), rhinomanometry, laboratory parameters were assessed, correlation-regression relationships of clinical and laboratory parameters and the concentration of chemicals in the blood were determined. &#x0D; Results. The study established for the first time the relationship between the concentration of chemical compounds in the blood, laboratory and instrumental indicators in children with URT pathology, living in the territory with excess levels of phenol, formaldehyde, acrolein. The total nasal airflow in the observation group was 10-15% lower than in the comparison group and inversely related to the blood concentration of acrolein, o-xylene, phenol, formaldehyde, and the content of IgG specific to phenol, myelopyroxidase, total number of lymphocytes, subpopulations of CD3+CD25+ and CD3+CD95+, integral index of proliferation and frequency of cells with apoptotic bodies and circular notches of the nucleus. &#x0D; Limitations. The results of the study can be extrapolated to 4-13 years children, boys and girls. The study did not include young children or adults. &#x0D; Conclusion. Characteristic features of the pathology of the upper respiratory tract associated with increased levels of acrolein, o-xylene, phenol and formaldehyde in the blood are a decrease in nasal airflow against the background of specific immune-dependent and non-specific inflammation. To reduce the incidence of URT in children, it is necessary to develop programs that include measures aimed at improving the quality of the environment, therapeutic and preventive measures that increase adaptive capacity.

The Effect of Trans-Sutural Distraction Osteogenesis on Nasal Bone, Nasal Septum, and Nasal Airway in the Treatment for Midfacial Hypoplasia in Growing Patients.

The purposes of this study were to analyze the effect of trans-sutural distraction osteogenesis (TSDO) on nasal bone, nasal septum, and nasal airway in the treatment of midfacial hypoplasia. A total of 29 growing patients with midfacial hypoplasia who underwent TSDO by a single surgeon were enrolled. The 3-dimensional measurement of nasal bone and nasal septum changes was performed using computed tomography (CT) images obtained preoperatively (T0) and postoperatively (T1). One patient was selected to establish 3-dimensional finite element models to simulate the characteristics of nasal airflow field before and after traction. After traction, the nasal bone moved forward significantly (P<0.01). The septal deviation angle was lower than that before traction (14.43±4.70 versus 16.86 ±4.59 degrees) (P<0.01). The length of the anterior and posterior margin of the vomer increased by 21.4% (P<0.01) and 27.6% (P<0.01), respectively, after TSDO. The length of the posterior margin of the perpendicular plate of ethmoid increased (P<0.05). The length of the posterior inferior and the posterior superior margin of the nasal septum cartilage increased (P<0.01) after traction. The cross-sectional area of nasal airway on the deviated side of nasal septum increased by 23.0% after traction (P<0.05). The analysis of nasal airflow field showed that the pressure and velocity of nasal airflow and the nasal resistance decreased. In conclusion, TSDO can promote the growth of the midface, especially nasal septum, and increase the nasal space. Furthermore, TSDO is conductive to improve nasal septum deviation and decrease nasal airway resistance.

Exploring the role of nasal hair in inhaled airflow and coarse dust particle dynamics in a nasal cavity: A CFD-DEM study

This study presents a novel coupled computational fluid dynamics-discrete element method (CFD-DEM) model for simulating airflow and inhaled particle dynamics in the nasal cavity, considering the fluid-structure interactions between nasal hair and airflow, which are often overlooked in existing CFD simulations. The CFD-DEM model, based on a virtual nasal cavity geometry, represents nasal hairs as flexible fibers implanted on the inner wall of the nasal cavity. Inhaled air-particle transport dynamics were simulated in the presence of nasal hairs with three different diameters (40, 95, and 120 μm), and the results were compared with simulations without nasal hairs. Polydisperse particles with diameters ranging from 5 to 15 μm, aligning with global coarse dust statistics, were inhaled at flow rates between 216 mL/s and 630 mL/s, representing human nose breathing conditions from rest to exercise. The CFD-DEM simulation results indicate that the differences in deposition fraction predictions between cases with and without nasal hairs exceed 20% for particle size ranges corresponding to impaction parameter values between 3E+3 and 2E+4 μm2cm3/s. This emphasizes the importance of accounting for nasal hair interactions in accurately simulating inhaled particle transport dynamics within the nasal cavity. Thinner nasal hairs, more flexible than thicker ones, lead to more significant deformation and allow more particles to penetrate the nasal vestibule without being trapped. Additionally, thinner hairs occupy a smaller cross-section area in the nasal vestibule, resulting in lower filtration capability due to decreased particle deposition from interception and inertial impaction. Thicker nasal hairs trap more coarse dust particles (> 5 μm) effectively than thinner nasal hairs. Moreover, as the nasal hair diameter increases, particle deposition on the nasal cavity wall decreases. Nasal hairs demonstrate higher efficiency in trapping smaller particles. In conclusion, the CFD-DEM model, capable of modeling nasal hair motion, can serve as a next-generation in silico tool for investigating biofluid dynamics in the nasal cavity.

0507 A wireless patch-based polysomnography system for conducting in-lab sleep studies

Abstract Introduction Current attended in-lab polysomnographic sleep studies are time-consuming and costly, primarily due to the time required to “hook-up” a patient to multiple electrodes and sensors and meet the quality assurance and safety requirements of an in-lab study. We developed a wireless PSG system (Onera STS - Onera Health, NL) consisting of four disposable patches and reusable pods to record full polysomnography that may reduce hook-up time while preserving standards of an attended polysomnography in the lab. Methods We used the Onera STS system for monitoring EEG, EOG, EMG, forehead reflectance SaO2, ECG, bioimpedance derived respiratory airflow and effort, airflow via nasal cannula, snoring sounds, body position, actigraphy, and leg movements, and accessory online monitoring of finger SaO2, ECG, nasal cannula airflow and video via RemLogic 4.0 or REM logic MPR system for Q/A and safety monitoring. Seventeen subjects (8 male, 9 female, age 18-to-75 yrs, BMI 29.9±6.0 kg/m2) were monitored for the evaluation of sleep apnea. We measured hook-up times and observed oxygen saturation and cardiac rhythm throughout the night. Results Mean hook-up time for the Onera STS was 5:22±1:17 minutes and for the additional on-line sensors (Finger SaO2, ECG and nasal cannula) was 3:15±1:10 minutes, resulting in an average hook-up time of less than 10 minutes. Onera PSG data revealed a mean oxygen desaturation event rate of &amp;gt;3% (ODI3) of 8.8 (SD 18.6) and a mean fall of oxygen saturation (ΔSaO2/event) of 4.4 (SD 1.2). The accessory online SaO2, ECG and video monitoring showed that no subjects demonstrated sustained nocturnal hypoxia, severe cardiac arrhythmia or parasomnia events that would have required interventions. Conclusion The Onera STS system substantially lowers the burden to conduct attended polysomnographic sleep studies. In combination with standard monitoring of SaO2, ECG and video, it meets the safety requirements for attended sleep studies while reducing the overall operational and capital equipment costs. The ease of application together with the reduced hook-up time makes it now possible to implement polysomnographic sleep studies in the hospital setting, particularly in addition to conventional bedside monitoring units such as ICU-, step-down unit- or hospital beds. Support (if any)

0427 Airway Pressures Define Collapsibility of Specific Pharyngeal Sites of Obstruction during Drug-induced Sleep Endoscopy

Abstract Introduction Obstructive sleep apnea (OSA) is characterized by repetitive episodes of pharyngeal obstruction at one or more collapse sites. Multilevel collapse is a negative predictive factor for PAP-alternative surgical treatments. Pharyngeal manometry during drug-induced sleep endoscopy (DISE) permits an objective evaluation of anatomical obstruction sites and mechanisms, and may play a role in patient selection for PAP alternative therapies. We hypothesized that patients with multilevel collapse would have primary velopharyngeal collapse and secondary, downstream sites. Methods This prospective cohort of twenty consecutive patients with diagnosed OSA underwent DISE with nasal airflow monitoring and pharyngeal manometry. Two pressure catheters were placed at the (1) distal margin of the soft palate (Pus) and (2) retroepiglottic space (Pds). We sought to delineate site(s) of collapse by evaluating dissociations in airflow and air pressure during inspiratory flow limitation and/or complete obstruction. The primary site of collapse was defined by the initial segment at which inspiratory airflow and pressure dissociated (the critical pressure, Pcrit). Secondary site(s) were defined as the pressure at which the Pus and/or Pds signals subsequently dissociated (beyond the initial point of maximal flow). Results Twenty-one patients were evaluated of which signal quality and catheter placement in twenty were sufficient for analysis. Participants were elderly (58.3±14.3yrs, mean±SD), overweight (BMI 28.7±2. kg/m2), and had moderate-severe OSA (AHI 28.2±14.2 events/hour). Six patients had a single site of collapse, of which one was naso-palatal (Pcrit -2.6cmH2O) and five were infra-palatal (mean Pcrit -1.3cmH2O). In the patients with multilevel collapse (N=14), all had primary naso-palatal collapse (mean Pcrit 0.17±2.0cmH2O) and secondary infra-palatal sites of collapse (mean Pcrit -11.7±5.8cmH2O). Pcrit differed between the primary and secondary site by 11.9±6.5cmH2O (p&amp;lt; 0.01). Conclusion These findings suggest that single-site pharyngeal collapse is usually infra-palatal. In contrast, multilevel collapse is primarily due to velopharyngeal collapse with varying degrees of instability in downstream pharyngeal segments. When secondary infra-palatal sites readily collapse with minimal additional respiratory effort, laxity of the tongue and/or lateral walls may be strongly implicated in the pathogenesis of pharyngeal obstruction. Future studies can utilize pharyngomanometry to further target specific pharyngeal structures for OSA therapy. Support (if any) National Institutes of Health 1R01HL144859 (PIs: Schwartz, Dedhia)

Nasal Airflow Dynamics Before and After Septorhinoplasty for Correction of Cleft Lip Nasal Deformity: A Single Patient Case Report

Background: Unilateral cleft lip nasal deformity (uCLND) creates multiple sites of nasal airway obstruction, impacting patients’ quality of life. Surgical restoration of function remains technically challenging and complex. Objectives: This is a single patient case report to determine consistency of patient’s subjective perception of nasal outcomes after septorhinoplasty with objective assessments, and effectiveness of standard surgical techniques in targeting sites of greatest nasal anatomical obstruction. Method: Patient-reported quality of life (QOL) measures were collected. Pre- and post-surgery radiographic images of a patient with uCLND were obtained for computational fluid dynamics (CFD) modeling of patient-specific nasal function. Objective assessments were obtained using rhinomanometry and CFD. CFD-derived localized resistance at multiple cross-sectional segments were determined and used to identify greatest nasal obstructive sites. Results: Patient-reported QOL scores improved by 20 to 73 points. CFD-calculated bilateral resistance decreased from 0.155 to 0.061 Pa.s/ml, cleft-side resistance from 0.407 to 0.091 Pa.s/ml, and non-cleft-side from 0.228 to 0.120 Pa.s/ml. Rhinomanometry showed similar decreases in resistance. On the cleft side, 25 identified sites of greatest obstruction decreased to 15 sites post-surgery; on the non-cleft side, 23 sites of greatest obstruction decreased to 16 sites post-surgery. Conclusion: Results suggest improvement in nasal patency after septorhinoplasty. Additional greatest obstructive sites in the post-surgical airway were mostly around the superior airway.

A new method for the assessment of adenoid hypertrophy: Respirdynamicsgram (RDG)

Adenoid hypertrophy (AH) is a common cause of airway obstruction in children, which is the etiology of changes in facial growth, obstructive sleep apnea syndrome, and/or more serious problems. Most sequelae can be avoided or reversed by timely diagnosis and treatment. It is difficult to frequently assess the changes in adenoids among children using the commonly available diagnostic tools owing to invasiveness and radiation exposure. A new method called respirdynamicsgram (RDG) is proposed for the assessment and diagnosis of AH. Specifically, RDG is generated by visualizing the respiratory dynamics extracted from nasal airflow through dynamic learning. The morphology of RDG remarkably differs between children with adenoidal hypertrophy (irregular shapes) and healthy children (regular butterfly-like shapes). Three features are utilized to represent the morphology of RDG, including temporal heterogeneity, spatial heterogeneity, and wing shape. These morphology features of RDG are fed into the linear support vector machine for the AH classification task. As a result, the proposed method achieves a mean accuracy of 86.6% over 100 resample folds on a total of 74 subjects. It is shown that RDG has the capability of distinguishing children with AH from healthy children. As it is simple, non-invasive, and secure, it is hopeful that RDG may become an effective method for timely and frequent assessment and diagnosis of AH.

Impact of sinonasal anatomic changes after endoscopic anterior skull base surgery on nasal airflow and air conditioning: a computational fluid dynamics study

Objective: To analyze the impact of the sinonasal anatomic changes after endonasal endoscopic anterior skull base surgery on the nasal airflow and heating and humidification by computational fluid dynamics (CFD), and to explore the correlation between the postoperative CFD parameters and the subjective symptoms of the patients. Methods: The clinical data in the Rhinology Department of the First Affiliated Hospital of Zhengzhou University from 2016 to 2021 were retrospectively analyzed. The patients received the endoscopic resection of the anterior skull base tumor were selected as the case group, and the adults whose CT scans had no sinonasal abnormalities were chosen as the control group. The CFD simulation was performed on the sinonasal models after reconstructed from the patients' sinus CT images during the post-surgical follow-up. All the patients were asked to complete the Empty Nose Syndrome 6-Item Questionnaire (ENS6Q) to assess the subjective symptoms. The comparison between two independent groups and the correlation analysis were carried out by using the Mann-Whitney U test and the Spearman correlation test in the SPSS 26.0 software. Results: Nineteen patients (including 8 males and 11 females, from 22 to 67 years old) in the case group and 2 patients (a male of 38 years old and a female of 45 years old) in the control group were enrolled in this study. After the anterior skull base surgery, the high-speed airflow moved to the upper part of the nasal cavity, and the lowest temperature shifted upwards on the choana. Comparing with the control group, the ratio of nasal mucosal surface area to nasal ventilation volume in the case group decreased [0.41 (0.40, 0.41) mm-1 vs 0.32 (0.30, 0.38) mm-1; Z=-2.04, P=0.041], the air flow in the upper and middle part of the nasal cavity increased [61.14 (59.78, 62.51)% vs 78.07 (76.22, 94.43)%; Z=-2.28, P=0.023], the nasal resistance decreased [0.024 (0.022, 0.026) Pa·s/ml vs 0.016 (0.009, 0.018) Pa·s/ml; Z=-2.29, P=0.022], the lowest temperature in the middle of the nasal cavity decreased [28.29 (27.23, 29.35)℃ vs 25.06 (24.07, 25.50)℃; Z=-2.28, P=0.023], the nasal heating efficiency decreased [98.74 (97.95, 99.52)% vs 82.16 (80.24, 86.91)%; Z=-2.28, P=0.023], the lowest relative humidity decreased [(79.62 (76.55, 82.69)% vs 73.28 (71.27, 75.05)%; Z=-2.28, P=0.023], and the nasal humidification efficiency decreased [99.50 (97.69, 101.30)% vs 86.09 (79.33, 87.16)%; Z=-2.28, P=0.023]. The ENS6Q total scores of all patients in the case group were less than 11 points. There was a moderate negative correlation between the proportion of the inferior airflow in the post-surgical nasal cavity negatively and the ENS6Q total scores (rs=-0.50, P=0.029). Conclusions: The sinonasal anatomic changes after the endoscopic anterior skull base surgery alter the nasal airflow patterns, reducing the efficiency of nasal heating and humidification. However, the post-surgical occurrence tendency of the empty nose syndrome is weak.

Correlations between gustatory, trigeminal, and olfactory functions and nasal airflow

PurposeTo determine the relationship of chemosensory screening and nasal airflow tests among the same set of participants, and to determine other factors that are related to the outcomes of these tests.MethodsParticipants had no chemosensory complaints. Structured medical history was taken. Participants underwent 5 screening tests: q-sticks (orthonasal olfaction), q-powders (retronasal olfaction), trigeminal lateralization test, taste sprays, and peak nasal inspiratory flow (PNIF). Ratings of smell/taste ability and nasal airflow were obtained using visual analogue scales (VAS). Composite sinusitis symptoms and significance of olfaction questionnaire scores were also determined.ResultsFour hundred participants were included in the study, 156 men, 244 women; aged 18–82 years (mean: 46). The q-powders and taste spray scores were weakly positively correlated with all the other chemosensory tests and PNIF. However, chemosensory test scores were not correlated with VAS, composite sinusitis symptoms, and significance of olfaction questionnaire scores. Various tests showed significant decrease starting at specific ages (in years, PNIF and trigeminal lateralization: 40, q-powders: 60, and q-sticks: 70).ConclusionChemosensory screening tests and self-rated chemosensory function showed no correlation in participants without chemosensory complaints. In addition, gustatory function appeared to be correlated with olfactory and trigeminal function but also with nasal airflow, and nasal airflow was related not only to olfactory but also to trigeminal and taste function. Over all, the results suggest that chemosensory functions (orthonasal olfactory, trigeminal, retronasal olfactory, gustatory) and nasal airflow are correlated with each other, which we propose may be possibly mediated, at least in part, through central nervous system interactions.

Modelling the effects of post-FESS middle turbinate synechiae on sinonasal physiology: A computational fluid dynamics study

Objective(s)Chronic rhinosinusitis (CRS) is common and often requires surgical intervention. Surgical failure may lead to persistent symptoms and recalcitrant disease, often secondary to synechiae between the middle turbinate (MT) and lateral nasal wall. Synechiae prevention techniques have been extensively investigated, however evidence for the effect of synechiae on sinonasal physiology is lacking. We aimed to model the effects of MT synechiae on a post-functional endoscopic sinus surgery (FESS) sinonasal cavity using computational fluid dynamics (CFD). MethodsDICOM data from a CT-sinus of a healthy 25-year-old female was segmented to create a three-dimensional model. Virtual surgery was performed to simulate a “full-house” FESS procedure. Multiple models were created, each with a single unilateral virtual MT synechia of varying extent. CFD analysis was performed on each model and compared with a post-FESS control model without synechiae. Airflow velocity, humidity and mucosal surface and air temperature values were calculated. ResultsAll synechiae models demonstrated aberrant downstream sinonasal airflow. There was reduced ventilation of the ipsilateral frontal, ethmoid and sphenoid sinuses, with a concentrated central “jet” in the middle meatus region. Effects were proportionate to the size of synechiae. The impact on bulk inspired airflow was negligible. ConclusionPost-FESS synechiae between the MT and lateral nasal wall significantly disrupt local downstream sinus ventilation and nasal airflow. These findings may explain the persistent symptoms seen in post-FESS CRS patients with MT synechiae, reinforcing the importance of prevention and adhesiolysis. Larger cohort studies with multiple models of actual post-FESS patients with synechiae are required to validate these findings.

Smell-related quality of life changes after total laryngectomy: a multi-centre study

PurposeA total laryngectomy creates an alternate airway for gas exchange that bypasses the upper aerodigestive tract. The subsequent reduction in nasal airflow, and therefore, reduction in deposition of particles to the olfactory neuroepithelium leads to hyposmia or anosmia. The aim of this study was to assess the quality of life impairment conferred by anosmia following laryngectomy and identify any specific patient-related risk factors that are associated with poorer outcomes.MethodsConsecutive patients with a total laryngectomy presenting for review at three tertiary head and neck services (in Australia, the United Kingdom and India) over a 12-month period were recruited. Patient demographic and clinical data were collected, and each subject completed the validated assessment of self-reported olfactory functioning and olfaction-related quality of life questionnaire (ASOF). Dichotomous comparisons were performed using the student's unpaired t-test for continuous variables (SRP), a chi-squared test for categorical variables, and a Kendall's tau-b for ordinal variables (SOC) to assess for a correlation with poorer questionnaire scores.ResultsA total of 66 laryngectomees (13.4% female; age 65.7 ± 8.6 years) were included in the study. The mean SRP score of the cohort was found to be 15.6 ± 7.4, while the mean ORQ score was noted to be 16.4 ± 8.1. No other specific risk factors associated with poorer quality of life were identified.ConclusionA significant quality of life detriment from hyposmia is conferred following laryngectomy. Further research to assess treatment options and the patient population that would best benefit from these interventions is required.

Functional septorhinoplasty alters brain structure and function: Neuroanatomical correlates of olfactory dysfunction.

We previously demonstrated functionally significant structural plasticity within the central olfactory networks, in association with improved olfaction after surgical treatment of chronic rhinosinusitis (CRS). In order to confirm and expand on these findings, the primary aim of this study was to determine whether these same regions undergo functionally significant structural plasticity following functional septorhinoplasty (fSRP), in patients with non-CRS olfactory dysfunction (OD) of mixed cause. fSRP has previously been shown to improve olfactory function, and the secondary aim of this study was to provide initial insights into the mechanism by which fSRP affects olfaction. We performed a pilot prospective, multimodal neuroimaging study in 20 participants undergoing fSRP, including patients with non-CRS OD of mixed cause, as well as normosmic surgical controls. Participants underwent psychophysical olfactory testing, assessment of nasal airway, structural and functional neuroimaging. This was performed pre- and postoperatively in patients, and preoperatively in controls. There was a statistically and clinically significant improvement in mean psychophysical olfactory scores after surgery. This was associated with structural and functional plasticity within areas of the central olfactory network (anterior cingulate, orbitofrontal cortex, insula, temporal pole). Improved psychophysical scores were significantly correlated with change in bilateral measures of nasal airflow, not measures of airflow symmetry, suggesting that improved overall airflow was more important than correction of septal deviation. This work highlights the importance of these neuroanatomical regions as potential structural correlates of olfactory function and dysfunction. Our results also provide initial insight into the mechanistic effects of fSRP on olfaction. Further work could investigate the utility of these regions as personalised biomarkers of OD, as well as the role of fSRP in treating OD.

Changes in nasolabial angle may alter nasal valve morphology and airflow: a computational fluid dynamics study

Aim: Nasal valve (NV) dysfunctions are a significant cause of nasal obstruction. Changes in the nasolabial angle (NLA) may also cause changes in NV morphology. The effect of changes in the 3D structure of the nasal valve region (NVR) on nasal airflow has yet to be studied sufficiently. The accuracy of computational fluid dynamics (CFD) simulation results of nasal airflow has been confirmed by in vitro tests. Therefore, this study aimed to evaluate the effect of changes in NV structure and volume on nasal airflow based on the CFD method.&#x0D; Material and Method: We used CT images to create a 3D structural model of the NVR. First, CT images were transferred to MIMICS® software, and the nasal air passage was modeled. A solid reference model of the NVR was then created using SolidWorks software. Five different solid 3D nasal valve models were created with nasolabial angles of 85˚ in Model 1, 90˚ in Model 2, 95˚ in Model 3, 100˚ in Model 4, and 105˚ in Model 5. To simulate breathing during rest and exercise using the CFD method, the unilateral nasal airflow rates were set at 150 ml/s and 500 ml/s, respectively. The CFD method was then used to calculate each model’s airflow properties. Finally, the volumes of the models, pressure at the NV outlet, and airflow velocity were evaluated and calculated to investigate each model’s NV airflow characteristics. &#x0D; Results: Our study found a significant correlation between the nasolabial angle (NLA) and NVR volume (r=-0.998, p=0.000), flow rate and velocity (r=0.984, p=0.000), velocity and maximum pressure (r=0.920, p=0.000), velocity and minimum pressure (r=-0.969, p=0.000), flow rate and maximum pressure (r=0.974, p=0.000), and flow rate and minimum pressure (r=-0.950, p=0.000). There was no correlation between NLA increase and nasal airflow velocity. We determined that the highest pressure and lowest airflow velocity values were in the upper angle region and that the lowest pressure and highest airflow velocity values were at the bottom of the NVR in all models.&#x0D; Conclusion: Using the CFD method, we found a decrease in NVR volume and an increase in airflow velocity with an increase in NLA. In addition, we found that the pressure values in the NVR did not change significantly with the increase in NLA.