A nose for tau.

Nasal delivery of an oligomeric tau antibody loaded into micelles reduces pathology and ameliorates cognition in a mouse model of tauopathy.

Retained foreign body in nose following eye injury.

A man in his 60s presented with diminution of vision of the left eye with nasal bleeding after accidental fall. On examination his left upper eyelid was lacerated and left temporal sclera was punctured which was repaired under local anaesthesia after which he was discharged by ophthalmologists but continued to complain of pain and left nasal obstruction. A non-contrast CT of paranasal sinuses revealed fracture of medial wall of left orbit, left ethmoid haemosinus and a metallic foreign body (FB) in the septum and anterior face of sphenoid. Diagnostic nasal endoscopy performed to remove the metallic FB showed plastic splinters embedded in the mucosa of nasal cavity which was unexpected. Hence, the FB was removed in two sittings because of diagnostic dilemma.

A multi-centric, single-blinded, randomized, parallel-group study to evaluate the effectiveness of nasoalveolar moulding treatment in non-syndromic patients with complete unilateral cleft lip, alveolus and palate (NAMUC study): a study protocol for a randomized controlled trial.

BACKGROUND: Cleft lip and palate (CLP) are among the most common congenital anomaly that affects up to 33,000 newborns in India every year. Nasoalveolar moulding (NAM) is a non-surgical treatment performed between 0 and 6 months of age to reduce the cleft and improve nasal aesthetics prior to lip surgery. The NAM treatment has been a controversial treatment option with 51% of the cleft teams in Europe, 37% of teams in the USA and 25 of cleft teams in India adopting this methodology. This treatment adds to the already existing high burden of care for these patients. Furthermore, the supporting evidence for this technique is limited with no high-quality long-term clinical trials available on the effectiveness of this treatment. METHOD: The NAMUC study is an investigator-initiated, multi-centre, single-blinded randomized controlled trial with a parallel group design. The study will compare the effectiveness of NAM treatment provided prior to lip surgery against the no-treatment control group in 274 patients with non-syndromic unilateral complete cleft lip and palate. The primary endpoint of the trial is the nasolabial aesthetics measured using the Asher McDade index at 5 years of age. The secondary outcomes include dentofacial development, speech, hearing, cost-effectiveness, quality of life, patient perception, feeding and intangible benefits. Randomization will be carried out via central online system and stratified based on cleft width, birth weight and clinical trial site. DISCUSSION: We expect the results from this study on the effectiveness of treatment with NAM appliance in the long term along with the cost-effectiveness evaluation can eliminate the dilemma and differences in clinical care across the globe. TRIAL REGISTRATION: ClinicalTrials.gov CTRI/2022/11/047426 (Clinical Trials Registry India). Registered on 18 November 2022. The first patient was recruited on 11 December 2022. CTR India does not pick up on Google search with just the trial number. The following steps have to be carried out to pick up. How to search: ( https://ctri.nic.in/Clinicaltrials/advsearch.php -use the search boxes by entering the following details: Interventional trial > November 2022 > NAMUC).

High burden of viruses and bacterial pathobionts drives heightened nasal innate immunity in children.

Studies during the COVID-19 pandemic showed that children had heightened nasal innate immune responses compared with adults. To evaluate the role of nasal viruses and bacteria in driving these responses, we performed cytokine profiling and comprehensive, symptom-agnostic testing for respiratory viruses and bacterial pathobionts in nasopharyngeal samples from children tested for SARS-CoV-2 in 2021-22 (n = 467). Respiratory viruses and/or pathobionts were highly prevalent (82% of symptomatic and 30% asymptomatic children; 90 and 49% for children <5 years). Virus detection and load correlated with the nasal interferon response biomarker CXCL10, and the previously reported discrepancy between SARS-CoV-2 viral load and nasal interferon response was explained by viral coinfections. Bacterial pathobionts correlated with a distinct proinflammatory response with elevated IL-1ß and TNF but not CXCL10. Furthermore, paired samples from healthy 1-year-olds collected 1-2 wk apart revealed frequent respiratory virus acquisition or clearance, with mucosal immunophenotype changing in parallel. These findings reveal that frequent, dynamic host-pathogen interactions drive nasal innate immune activation in children.

Persistent enrichment of multidrug-resistant Klebsiella in oral and nasal communities during long-term starvation.

BACKGROUND: The human oral and nasal cavities can act as reservoirs for opportunistic pathogens capable of causing acute infection. These microbes asymptomatically colonize the human oral and nasal cavities which facilitates transmission within human populations via the environment, and they routinely possess clinically significant antibiotic resistance genes. Among these opportunistic pathogens, the Klebsiella genus stands out as a notable example, with its members frequently linked to nosocomial infections and multidrug resistance. As with many colonizing opportunistic pathogens, the essential transmission factors influencing the spread of Klebsiella species among both healthy and diseased individuals remain unclear. RESULTS: Here, we explored a possible explanation by investigating the ability of oral and nasal Klebsiella species to outcompete their native microbial community members under in vitro starvation conditions, which could be analogous to external hospital environments or the microenvironment of mechanical ventilators. When K. pneumoniae and K. aerogenes were present within a healthy human oral or nasal sample, the bacterial community composition shifted dramatically under starvation conditions and typically became enriched in Klebsiella species. Furthermore, introducing K. pneumoniae exogenously into a native microbial community lacking K. pneumoniae, even at low inoculum, led to repeated enrichment under starvation. Precise monitoring of K. pneumoniae within these communities undergoing starvation indicated rapid initial growth and prolonged viability compared to other members of the microbiome. K. pneumoniae strains isolated from healthy individuals' oral and nasal cavities also exhibited resistance to multiple classes of antibiotics and were genetically similar to clinical and gut isolates. In addition, we found that in the absence of Klebsiella species, other understudied opportunistic pathogens, such as Peptostreptococcus, increased in relative abundance under starvation conditions. CONCLUSIONS: Our findings establish an environmental and microbiome community circumstance that allows for the enrichment of Klebsiella species and other opportunistic pathogens. Klebsiella's enrichment may hinge on its ability to quickly outgrow other members of the microbiome. The ability to outcompete other commensal bacteria and to persist under harsh environmental conditions could be an important factor that contributes to enhanced transmission in both commensal and pathogenic contexts. Video Abstract.

Discovery and characterization of BRBV-sheep virus in nasal swabs from domestic sheep in China.

Introduction: The escalating occurrence of infectious disease outbreaks in humans and animals necessitates innovative, effective, and integrated research to better comprehend their transmission and dynamics. Viral infection in livestock has led to profound economic losses globally. Pneumonia is the prevalent cause of death in sheep. However, very few studies exist regarding virus-related pathogens in sheep. Metagenomics sequencing technologies in livestock research hold significant potential to elucidate these contingencies and enhance our understanding. Methods: Therefore, this study aims to characterize respiratory viromes in paired nasal swabs from Inner Mongolian feedlot sheep in China using metaviromic sequencing. Through deep sequencing, de novo assembly, and similarity searches using translated protein sequences, several previously uncharacterized and known viruses were identified in this study. Results: Among these discoveries, a novel Bovine Rhinitis B Virus (BRBV) (BRBV-sheep) strain was serendipitously detected in the nasal swabs of domestic sheep (Ovis aries). To facilitate further molecular epidemiological studies, the entire genome of BRBV-sheep was also determined. Owing to the unique sequence characteristics and phylogenetic position of BRBV-sheep, genetically distinct lineages of BRBV in sheep may exist. A TaqMan-based qRT-PCR assay targeting the 3D polymerase gene was developed and used to screen 592 clinical sheep specimens. The results showed that 44.59% of the samples (264/592) were positive. These findings suggest that BRBV sheep are widespread among Inner Mongolian herds. Conclusion: This discovery marks the initial identification of BRBV in sheep within Inner Mongolia, China. These findings contribute to our understanding of the epidemiology and genetic evolution of BRBV. Recognizing the presence of BRBV in sheep informs strategies for disease management and surveillance and the potential development of targeted interventions to control its spread.

Nasal microbiome and the effect of nasal decolonization with a novel povidone-iodine antiseptic solution: a prospective and randomized clinical trial.

The aim of this study was to assess the profile of nasal microbiome and evaluate the effect of a specific nasal decolonization solution on the microbiome. We conducted a randomized, placebo-controlled, and parallel-group clinical study of 50 volunteers aged 18 years and older. The subjects were randomly assigned to receive a nasal antiseptic solution, containing povidone-iodine as the main ingredient, (n = 25) or a control solution (n = 25). Nasal swabs were obtained before application (baseline) and at 3 timepoints after application (5 min, 2 h, 24 h). Nasal swabs were subjected to next generation sequencing analysis and cultured in agar plates. At baseline, there were substantial associations between anaerobic species, Corynebacterium spp., Staphylococcus spp., and Dolosigranulum spp. Then, a high bioburden reduction was observed after the application of povidone-iodine (log10 3.68 ± 0.69 at 5 min; log10 3.57 ± 0.94 at 2 h; log10 1.17 ± 1.40 at 24 h), compared to the control. The top species affected by the treatment were Cutibacterium acnes, Staphylococcus, and Corynebacterium species. None of the subjects experienced any adverse effects, nor increases in mucociliary clearance time. Antiseptic solutions applied to the anterior nares can transiently and markedly reduce the bioburden of the nose. The registration number for this clinical trial is NCT05617729.

Outcomes of dorsal nasal augmentation using costochondral graft.

Objective: To assess functional and aesthetic outcomes in patients having undergone dorsal nasal augmentation with costochondral graft in a tertiary care setting. METHODS: The single-centre, retrospective, observational study was conducted at Shifa International Hospital, Islamabad, Pakistan, and comprised data of patients who underwent dorsal nasal augmentation using costochondral graft between January 1, 2018, and December 31, 2022. Aesthetic outcomes in terms of patient satisfaction were assessed using Facial Appearance, Health-related Quality of Life and Adverse Effects scores. Data was analysed using SPSS 26. RESULTS: Of the 46 patients, 28(61%) were males and 18(39%) were females. The overall mean age was 28.39±9.13 years. Dorsal nasal deficiency occurred secondary to congenital causes in 12(26.1%) patients, trauma 19(41.3%) and prior surgery 15(32.6%). Postoperative complication rate was 7(15%); 3(6.5%) had recipient site infection and 2(4.3%) had rib graft resorption. Besides, 1(2.2%) patient reported pain 2 months postoperatively and 1(2.2%) had hypertrophic scarring. Patient satisfaction with the outcome was noted in all the 10 parameters analysed. Most commonly reported problem was that the nose was 'looking thick/swollen' by 12(26.1%) patients, but the issue resolved during 1-year follow-up. Conclusion: Costochondral graft was found to be an ideal material for dorsal nasal augmentation, with high patient satisfaction rate.

Vowel nasalization does not cue ambisyllabicity in American English nasals: Evidence from nasometrya).

Using visual spectrographic examination of vowel nasalization to diagnose the syllabic affiliation of phonologically ambisyllabic nasal consonants (e.g., gamma), Durvasula and Huang [(2017). Lang. Sci. 62, 17-36] argued that anticipatory vowel nasalization in these words patterns with word-medial codas. Using nasometry, the current study finds that anticipatory nasalization before monomorphemic and multimorphemic (scammer) ambisyllabic nasals differ from word-medial coda (gamble) and word-final nasals (scam), but not from other intervocalic nasals. Additionally, vowel nasalization is sensitive to the manner of the preceding phoneme. These findings demonstrate that quantifying anticipatory nasalization using nasometry differs from visual spectrographic criteria.

Do tight nosebands have an effect on the upper airways of horses?

BACKGROUND/OBJECTIVES: The public perception relating to the welfare of horses involved with equestrian sports is associated with training methods used and the presentation of horses at events. In this context, very tight nosebands, which are intended to prevent the horse from opening its mouth, also attract a lot of attention. Various studies have evaluated the impact of tight nosebands on stress parameters, whereas the effect of tight nosebands on upper airway function is unknown. Therefore, the aim of the study was to use overground endoscopy to evaluate changes in pharyngeal and laryngeal function when a tight noseband is fitted. Moreover, the ridden horse pain ethogram (RHpE) was applied to investigate signs of discomfort (Dyson et al., 2018). STUDY DESIGN: A randomized, blinded, and prospective study was performed. METHODS: Sixteen warmblood horses consisting of twelve mares and four geldings with a mean age of 11.63 ± 3.53 years were ridden on 2 consecutive days with either loose or tight nosebands (two fingers or no space between bridge of the nose and noseband, respectively) and inserted endoscope in a random order. Videos were taken in a riding arena during a standardized exercise protocol involving beginner level tasks for 30 min in all gaits. For video analysis, freeze frames were prepared and analyzed at the beginning of the expiration phase. Pharyngeal diameter was measured using the pharynx-epiglottis ratio. Other findings (swallowing, pharyngeal collapse, soft palate movements, and secretion) were also evaluated. Moreover, the RHpE was applied. Descriptive statistics and generalized linear mixed effects models were used. Results with a p-value < 0.05 were considered statistically significant. RESULTS: While the pharynx-epiglottis ratio did not change significantly in horses ridden with loose versus tight nosebands, there was an increase in mean grade and total counts of parameters assessed in the pharyngeal region, for example, grade of secretion (1.5 [±SD 0.89] vs. 3.13 [±SD 0.96]; p = 0.0001), axial deviation of the aryepiglottic folds (0.29 [±SD 0.73] vs. 1.33 [±SD 1.44]; p = 0.01), and pharyngeal collapse (0.69 [±SD 0.87] vs. 1.88 [±SD 1.54]; p = 0.005) in horses ridden with tight nosebands. There was no RHpE score above 8 indicating musculoskeletal pain, but the RHpE scores were significantly higher in horses ridden with tight nosebands (p < 0.001). MAIN LIMITATIONS: Video quality was limited when horses showed large amounts of secretion. Another limitation was the small number of horses. CONCLUSIONS: Results add to the evidence obtained in other studies that tight nosebands do not only cause adverse reactions based on the RHpE score such as head behind the vertical or intense staring but also contribute to changes in the pharyngeal region, such as increased secretion and collapse of pharyngeal structures. This may provide further support for future decisions regarding regulations on nosebands.

Reconstruction of caudal defects of the nose using the bilobe flap: A long-term follow-up retrospective review.

BACKGROUND: Reconstruction of nasal defects is a challenging task due to the complex nasal geometry and the need for aesthetic considerations. The bilobe flap has emerged as a reliable technique for nasal reconstruction, particularly for defects involving the nasal tip, alae, and inferior dorsum. OBJECTIVE: This study presents a review of 31 patients who underwent bilobe flap reconstruction for nasal defects after tumor resection. MATERIALS AND METHODS: The surgical technique, short- and long-term aesthetic outcomes, patient satisfaction, and complications were evaluated. Aesthetic outcomes were assessed using a qualitative ordinal scale, and long-term patient satisfaction was obtained through follow-up notes and phone interviews. RESULTS: Bilobe flap reconstruction yielded good aesthetic outcomes in the majority of cases, with high patient satisfaction. Complications were minimal, and revision surgeries were performed in a small number of cases to address aesthetic concerns. CONCLUSION: Overall, the bilobe flap technique proved to be an effective and reliable option for nasal reconstruction, providing stable and long-lasting results.

Impact of Piezo and other Osteotomy Models on Soft Tissue, Blood Oxidative Stress, and Proinflammatory Markers.

BACKGROUND: Rhinoplasty is a common surgical procedure used in nose esthetics and pathologies. Shaping the nasal bones is a crucial step in achieving successful rhinoplasty surgery. However, complications such as excessive bleeding, edema, mucosal damage, and periosteal damage may occur during osteotomy for nose shaping. AIM: To investigate the damage to soft tissue and the effects on oxidative stress and proinflammatory cytokines in the blood caused by osteotomy performed on rabbits, using different osteotomy methods. Methods: Thirty-two albino New Zealand rabbits were divided into four groups. Group A was the sham group (n = 8), Group B the piezoelectric device group (n = 8), Group C the manual saw group (n = 8), and Group D the classical osteotomy group (n = 8). About 3 ml of blood was drawn to compare preoperative and postoperative interleukin-1ß (IL-1ß), thiobarbituric acid-reactive substances (TBARS), tumor necrosis factor-alpha (TNF-alpha), nitric oxide (NO), interleukin-10 (IL-10), and glutathione (GSH) levels. A 1 mm3 piece of soft tissue from the nasal bone of each animal in the study groups was sent for histopathological examination. The Chi-square test was used to analyze the incidence of postoperative necrosis, inflammation, and edema in the groups. RESULTS: Histopathologically, edema was significantly higher in Group C and Group D compared to Group B. Inflammation was increased in all groups. The necrosis was significantly higher in Group B compared to Group C and Group D. Except for two parameters, no significant changes were found in the biochemical markers for all groups. CONCLUSIONS: The piezoelectric device was found to be a better option for reducing edema and inflammation, while manual saws and classical osteotomy may lead to more tissue damage.

Facial soft-tissue shape changes after fixed edgewise treatment with premolar extraction in individual artificial-intelligence-classified facial profile patterns.

OBJECTIVE: To examine the patterns of pretreatment facial soft tissue shape in orthodontic cases with premolar extraction using artificial intelligence (AI) and to investigate the corresponding changes. METHODS: One hundred and fifty-two patients who underwent orthodontic treatment with premolar extraction were enrolled. Lateral cephalograms were obtained before and after the treatment. For each record, the outlines of the nose-lip-chin profile and corresponding 21 cephalometric variables were extracted. The AI method classified pretreatment records into three subject groups based on the feature variables extracted from the outline. Dentoskeletal and soft tissue facial form changes observed after treatment were compared statistically (P < 0.05) between the groups using ANOVA. Multivariate regression models were used for each group. RESULTS: Group 1 (n = 59) was characterized by Class II high-angle retrognathic mandible with an incompetent lip, group 2 (n = 55) by Class I malocclusion with retruded and thin lips, and group 3 (n = 38) by Class I malocclusion with an everted superior lip before treatment. The ratios of anteroposterior soft tissue to hard tissue movements in Group 1 were 56% (r = 0.64) and 83% (r = 0.75) for the superior and inferior lips, respectively, whereas those in Group 2 were 49% (r = 0.78) and 91% (r = 0.80), and 40% (r = 0.54) and 79% (r = 0.70), respectively, in Group 3. CONCLUSIONS: The modes of facial form changes differed depending on the pre-treatment profile patterns classified by the AI. This indicates that the determination of the pre-treatment profile pattern can help in the selection of soft tissue to hard tissue movement ratios, which helps estimate the post-treatment facial profile with a moderate to high correlation.

Analysis of the Nasal Microbiota in Healthy and Diseased Pigs.

Massive sequencing of a fragment of 16S rRNA gene allows the characterization of bacterial communities in different body sites: the microbiota. Nasal microbiota can be analyzed by DNA extraction from nasal swabs, amplification of the specific fragment of interest, and posterior sequencing. The raw sequences obtained need to go through a computational process to check their quality and then assign the taxonomy. Here, we will describe the complete process from sampling to get the microbial diversity of nasal microbiota in health and disease.

The nasal microbiota is a potential diagnostic biomarker for sepsis in critical care units.

This study aimed to characterize the composition of intestinal and nasal microbiota in septic patients and identify potential microbial biomarkers for diagnosis. A total of 157 subjects, including 89 with sepsis, were enrolled from the affiliated hospital. Nasal swabs and fecal specimens were collected from septic and non-septic patients in the intensive care unit (ICU) and Department of Respiratory and Critical Care Medicine. DNA was extracted, and the V4 region of the 16S rRNA gene was amplified and sequenced using Illumina technology. Bioinformatics analysis, statistical processing, and machine learning techniques were employed to differentiate between septic and non-septic patients. The nasal microbiota of septic patients exhibited significantly lower community richness (P = 0.002) and distinct compositions (P = 0.001) compared to non-septic patients. Corynebacterium, Staphylococcus, Acinetobacter, and Pseudomonas were identified as enriched genera in the nasal microbiota of septic patients. The constructed machine learning model achieved an area under the curve (AUC) of 89.08, indicating its efficacy in differentiating septic and non-septic patients. Importantly, model validation demonstrated the effectiveness of the nasal microecological diagnosis prediction model with an AUC of 84.79, while the gut microecological diagnosis prediction model had poor predictive performance (AUC = 49.24). The nasal microbiota of ICU patients effectively distinguishes sepsis from non-septic cases and outperforms the gut microbiota. These findings have implications for the development of diagnostic strategies and advancements in critical care medicine.IMPORTANCEThe important clinical significance of this study is that it compared the intestinal and nasal microbiota of sepsis with non-sepsis patients and determined that the nasal microbiota is more effective than the intestinal microbiota in distinguishing patients with sepsis from those without sepsis, based on the difference in the lines of nasal specimens collected.

Automatic Sleep Stage Classification Using Nasal Pressure Decoding Based on a Multi-Kernel Convolutional BiLSTM Network.

Sleep quality is an essential parameter of a healthy human life, while sleep disorders such as sleep apnea are abundant. In the investigation of sleep and its malfunction, the gold-standard is polysomnography, which utilizes an extensive range of variables for sleep stage classification. However, undergoing full polysomnography, which requires many sensors that are directly connected to the heaviness of the setup and the discomfort of sleep, brings a significant burden. In this study, sleep stage classification was performed using the single dimension of nasal pressure, dramatically decreasing the complexity of the process. In turn, such improvements could increase the much needed clinical applicability. Specifically, we propose a deep learning structure consisting of multi-kernel convolutional neural networks and bidirectional long short-term memory for sleep stage classification. Sleep stages of 25 healthy subjects were classified into 3-class (wake, rapid eye movement (REM), and non-REM) and 4-class (wake, REM, light, and deep sleep) based on nasal pressure. Following a leave-one-subject-out cross-validation, in the 3-class the accuracy was 0.704, the F1-score was 0.490, and the kappa value was 0.283 for the overall metrics. In the 4-class, the accuracy was 0.604, the F1-score was 0.349, and the kappa value was 0.217 for the overall metrics. This was higher than the four comparative models, including the class-wise F1-score. This result demonstrates the possibility of a sleep stage classification model only using easily applicable and highly practical nasal pressure recordings. This is also likely to be used with interventions that could help treat sleep-related diseases.

Self-swabbing versus assisted swabbing for viral detection by qRT-PCR: the experience from SARS-CoV-2 based on a meta-analysis of six prospectively designed evaluations conducted in a UK setting.

PURPOSE: In April 2020, the UK Government implemented NHS Test and Trace to provide SARS-CoV-2 quantitative reverse transcription polymerase chain reaction (qRT-PCR) testing for the public, with nose-and-throat swabbing for samples performed by trained staff. Self-swabbing (SS) would allow rapid scale-up of testing capacity and access. Six studies were undertaken to determine whether SS was as effective for detecting SARS-CoV-2 as swabbing performed by trained staff. METHODS: Six prospective studies were conducted between April-October 2020, using six swab/media combinations. Differences between assisted swabbing (AS) and SS were evaluated for concordance, positivity, sensitivity, cycle threshold (Ct) values and void rates. Statistical analysis was performed using 95% confidence intervals (CIs), paired t-tests and model-based methods. RESULTS: Overall, 3,253 individuals were recruited (median age 37 years, 49% female), with 2,933 having valid paired qRT-PCR results. Pooled concordance rate was 98% (95% CI: 96%, 99%). Positivity rate differences for SS (8.1%) and AS (8.4%) and differences in pooled sensitivities between SS (86%; 95% CI: 78%, 92%) and AS (91%; 95% CI: 78%, 96%) were nonsignificant. Both types of swabbing led to pooled void rates below 2% and strongly correlated Ct values. Age, sex and previous swabbing experience did not have a significant impact on concordance or sensitivity. CONCLUSION: The UK adopted a policy to promote self-testing for SARS-CoV-2 based on data demonstrating equivalence of SS versus AS. Positive outcomes with SS are likely generalisable to testing for other respiratory pathogens, and we consider self-sampling and self-testing essential for future pandemic preparedness.

Computational analysis of nasal airflow and its alteration by a nasal dilator.

Nasal airflow obstruction correlates with several ailments, such as higher patency, increased friction at the mucosal wall or the so-called Little's area, improper air conditioning, and snoring. Nasal dilators are frequently employed, mainly due to their ease of access and use, combined with their non-permanent and non-surgical nature. Their overall efficacy, however, has not been clearly demonstrated so far, with some studies reporting conflicting outcomes, mainly because being based on subjective evaluations. This study employs Computational Fluid Dynamics simulations to analyze the flow inside a real nose, performs an objective assessment of a nasal dilator's effect in terms of airflow and air conditioning, reporting flow paths, friction levels, heat and water fluxes and detailed temperature and humidity distributions. Coincidentally, the studied nose presents a septal deviation, with one nostril being wider than the other. The tubes of the dilator used in both nostrils are identical, as with any standard commercial dilator. Consequently, the dilator widens one nostril, as intended, but results in an obstruction in the other. This allows simultaneously addressing two situations, the nominal function of the dilator, as well as an off-design case. Results indicate a 24 % increase in nasal patency in the design situation. The effect, however, is limited, as quantified by appropriate measures, such as the flow-generated friction at the nose surfaces and the temperature fluxes. Hence, the effect of such a dilator in nominal conditions is perhaps not as large as might be hoped. In the off-design situation, nasal resistance increases by 62 %, an undesirable effect, illustrating the consequences of using an inappropriate dilator.