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.

Comparing Airway Analysis in Two-Time Points after Rapid Palatal Expansion: A CBCT Study

BACKGROUND

The aim of this study is to investigate the upper airway analysis at two-time points after the rapid maxillary expansion was performed, using cone-beam computed tomography.

METHODS

Subjects from the Orthodontic Department at the Aristotle University of Thessaloniki with unilateral or bilateral posterior crossbite were screened according to the selection criteria. A sample size calculation was performed, and a total of 14 subjects were recruited. All subjects received a rapid maxillary expansion with a Hyrax-type device as part of their comprehensive treatment. A CBCT was taken before the treatment (T1), immediately after the expansion was completed (T2), and 6 months after (T3). Their upper airway was measured using the CBCT images. Airway volume (V) and minimal cross-sectional area (MCS) were extracted and compared using SPSS to analyze the means.

RESULTS

A statistically significant difference was found between all time points regarding both V and MCS (p < 0.001, p = 0.001). There was a statistically significant increase in both V and MCS measurements immediately after RPE expansion (T1-T2) and six months after expansion (T1-T3). Between the end of expansion and 6 months after (T2-T3), there was a decrease in V and no statistical difference in MCS.

CONCLUSIONS

RPE can significantly increase the volume and minimal cross-sectional area of the nasal passage airway.

Numerical modelling of micron particle inhalation in a realistic nasal airway with pediatric adenoid hypertrophy: A virtual comparison between pre- and postoperative models

Adenoid hypertrophy (AH) is an obstructive condition due to enlarged adenoids, causing mouth breathing, nasal blockage, snoring and/or restless sleep. While reliable diagnostic techniques, such as lateral soft tissue x-ray imaging or flexible nasopharyngoscopy, have been widely adopted in general practice, the actual impact of airway obstruction on nasal airflow and inhalation exposure to drug aerosols remains largely unknown. In this study, the effects of adenoid hypertrophy on airflow and micron particle inhalation exposure characteristics were analysed by virtually comparing pre- and postoperative models based on a realistic 3-year-old nasal airway with AH. More specifically, detailed comparison focused on anatomical shape variations, overall airflow and olfactory ventilation, associated particle deposition in overall and local regions were conducted. Our results indicate that the enlarged adenoid tissue can significantly alter the airflow fields. By virtually removing the enlarged tissue and restoring the airway, peak velocity and wall shear stress were restored, and olfactory ventilation was considerably improved (with a 16∼63% improvement in terms of local ventilation speed). Furthermore, particle deposition results revealed that nasal airway with AH exhibits higher particle filtration tendency with densely packed deposition hot spots being observed along the floor region and enlarged adenoid tissue area. While for the postoperative model, the deposition curve was shifted to the right. The local deposition efficiency results demonstrated that more particles with larger inertia can be delivered to the targeted affected area following Adenoidectomy (Adenoid Removal). Research findings are expected to provide scientific evidence for adenoidectomy planning and aerosol therapy following Adenoidectomy, which can substantially improve present clinical treatment outcomes.

New insights into the variability of upper airway morphology in modern humans

The biological adaptation of the human lineage to its environment is a recurring question in paleoanthropology. Particularly, how eco-geographic factors (e.g., environmental temperature and humidity) have shaped upper airway morphology in hominins have been subject to continuing debate. Nasal shape is the result of many intertwined factors that include, but are not limited to, genetic drift, sexual selection, or adaptation to climate. A quantification of nasal airway (NA) morphological variation in modern human populations is crucial to better understand these multiple factors. In the present research, we study 195 in vivo CT scans of adult individuals collected in five different geographic areas (Chile, France, Cambodia, Russia, and South Africa). After segmentation of the nasal airway, we reconstruct 3D meshes that are analyzed with a landmark-free geometric morphometrics method based on surface deformation. Our results highlight subtle but statistically significant morphological differences between our five samples. The two morphologically closest groups are France and Russia, whose NAs are longer and narrower, with an important protrusion of the supero-anterior part. The Cambodian sample is the most morphologically distinct and clustered sample, with a mean NA that is wider and shorter. On the contrary, the Chilean sample form the most scattered cluster with the greatest intra-population variation. The South African sample is morphologically close to the Cambodian sample, but also partially overlaps the French and Russian variation. Interestingly, we record no correlation between NA volume and geographic groups, which raises the question of climate-related metabolic demands for oxygen consumption. The other factors of variation (sex and age) have no influence on the NA shape in our samples. However, NA volume varies significantly according both to sex and age: it is higher in males than in females and tends to increase with age. In contrast, we observe no effect of temperature or humidity on NA volume. Finally, we highlight the important influence of asymmetries related to nasal septum deviations in NA shape variation.

Structural and functional changes of nasal cavity and maxillary sinus in patients with skeletal class III malocclusion 1 year after bimaxillary surgery

PURPOSE

This study aimed to analyse changes in the nasal cavity and maxillary sinus structure and function in patients with skeletal class III malocclusion 1 year after bimaxillary surgery.

MATERIALS AND METHODS

In this study, cone-beam computed tomography (CBCT) images of 20 patients (10 men and 10 women; mean age 24.3 ± 3.4 years) with skeletal class III malocclusion who underwent Le Fort I osteotomy and bilateral sagittal split osteotomy were obtained before and 1 year after the surgery. CBCT data were stored opened with element 3D (E3D) to establish a nasal airway model (the paranasal sinus includes only the maxillary sinus). Ansys (ANSYS) software is used for simulation and analysis.

RESULTS

The maxillary sinus and nasal cavity volumes decreased significantly 1 year after the surgery. After surgery, the volume of nasal cavity decreased by 13.5%, and the average volume of maxillary sinus decreased by 7.8%. There was no significant difference in the degree of deviation of the septum and nasal cavity resistance, and air distribution in the maxillary sinus did not change. The nasal cavity wall shear stress change was similar to that before surgery.

CONCLUSIONS

The maxillary sinus volume and nasal cavity volume of patients with skeletal class III malocclusion changed significantly after bimaxillary surgery, but there was no significant change in nasal ventilation function 1 year after surgery.

The Use of Infrared Thermal Imaging to Determine Functional Nasal Adequacy: A Pilot Study

Objective

The goal of this study was to establish a numeric threshold to separate functional from substantially obstructed noses using comparisons of thermal imaging and subjective scores.

Study Design

An inexpensive smartphone application and hardware attachment that uses infrared thermal imaging was tested to differentiate between substantial nasal blockage from an adequately functioning nose.

Setting

Sequential adult participants who presented to a public hospital otolaryngology clinic between June and August 2018 were asked to complete the Nasal Obstruction Symptom Evaluation (NOSE) tool.

Methods

A thermal video imaging device was used to record the difference in temperature (ΔT) between inspired (I) and expired (E) air at each nostril. The nostril ΔT between I and E air of patients with severe obstruction by the subjective measure (NOSE score) was compared with that of patients with minimal symptoms.

Results

A total of 26 participants were enrolled in the study. During normal respiration, Total ΔT for the nonobstructed group had a mean of 9.0, whereas the Total ΔT for the obstructed group had a mean of 7.69, a 17% difference that was statistically significant at P = .045. For the worst-performing nostril tested, ΔT for the nonobstructed group had a mean/median of 4°C, while the obstructed group had a mean of 3.23°C (median 3; 23.8% difference, P = .023).

Conclusion

Measures of thermal imaging, particularly at the threshold between the median scores of the worst-performing nostril, may be a useful clinical test to differentiate between a substantially obstructed nose from an adequately functioning nose, although more data are required.

[Advances in etiology and mechanism of structural nasal obstruction]

Structural nasal obstruction（SNO） is a series of diseases caused by congenital or acquired structural anatomical abnormalities of nasal airway and its surrounding tissues, which leads to increased nasal ventilation resistance. The effect of medication drugs for SNO is poor and surgical intervention is often needed. However, the abnormal structure of nasal airway is very complex, including the periphery of nasal airway, internal nasal airway, the front and rear of nasal airway and complex factors. These abnormal structures may interfere with the nasal airflow mechanics by changing the nasal ventilation volume and disrupting the symmetry of the bilateral nasal cavity, and finally lead to subjective feeling of nasal obstruction. In addition, the structure of nasal airway has plasticity. After the abnormal structure appears, the corresponding compensation of nasal airway can occur to ensure normal nasal ventilation and bilateral nasal cavity symmetry. Therefore, the SNO is the result of the failure of nasal airway remodeling after the appearance of abnormal structures. The etiology of SNO is complex, involving original structural abnormalities, nasal symmetry changing and nasal airway structure remodeling. Therefore, accurate identification of the main factors leading to SNO is the vitalpremise of making personalized nasal ventilation surgery.

Transcriptome Analysis Identifies Doublesex and Mab-3 Related Transcription Factor (DMRT3) in Nasal Polyp Epithelial Cells of Patients Suffering from Non-Steroidal Anti-Inflammatory Drug-Exacerbated Respiratory Disease (AERD)

Background: Aspirin-exacerbated respiratory disease (AERD) is a syndrome characterised by chronic rhinosinusitis, nasal polyps, asthma and aspirin intolerance. An imbalance of eicosanoid metabolism with anover-production of cysteinyl leukotrienes (CysLTs) has been associated with AERD. However, the precise mechanisms underlying AERD are unknown. Objective: To establish the transcriptome of the nasal polyp airway epithelial cells derived from AERD patients to discover gene expression patterns in this disease. Methods: Nasal airway epithelial cells were isolated from 12 AERD polyps and 8 AERD non-polyp nasal mucosa samples as controls from the same subjects. Utilising the Illumina HiSeq 2500 platform, RNA samples were sequenced. Potential gene candidate DMRT3 was selected from the differentially-expressed genes for validation. Results: Comparative transcriptome profiling of nasal epithelial cells was accomplished in AERD. A total of 20 genes had twofold mean regulation expression differences or greater. In addition, 8 genes were upregulated, including doublesex and mab-3 related transcription factor 3 (DMRT3), and 12 genes were downregulated. Differentially regulated genes comprised roles in inflammation, defence and immunity. Metabolic process and embryonic development pathways were significantly enriched. Enzyme-linked immune sorbent assay (ELISA) results of DMRT3 in AERD patients were significantly upregulated compared to controls (p = 0.03). Immunohistochemistry (IHC) of AERD nasal polyps localised DMRT3 and was predominantly released in the airway epithelia. Conclusion: Findings suggest that DMRT3 could be potentially involved in nasal polyp development in AERD patients. Furthermore, several genes are downregulated, hinting at the dedifferentiation phenomenon in AERD polyps. However, further studies are imperative to confirm the exact mechanism of polyp formation in AERD patients.

Simple, but effective: Nasal splinting for airway securement in free flap reconstruction following orbital exenteration

Orbital exenteration is a disfiguring procedure that often results in free tissue transfer for reconstructive purposes. The reconstructive focus is the obliteration of dead space while sparing the nasal airway, particularly if the medial orbital wall was resected. Prolapse of transferred tissue into the nasal airway may cause breathing difficulties drastically compromising quality of life. The objective of this study was to demonstrate the effectiveness and feasibility of temporary nasal septum splints as mechanical support for transferred tissue, to prevent airway obstruction. This novel application technique was employed in three patients between 2017 and 2018. No flap loss or sino‐orbital fistulas were observed. On postoperative MRI and endoscopy, a patent nasal airway was observed at all times. Temporary nasal splinting in combination with free tissue transfer proved to be a simple, but effective reconstructive option for securing the nasal airway following orbital exenteration with resection of the medial orbital wall.

Role for Mucin-5AC in Upper and Lower Airway Pathogenesis in Mice

Mucin-5AC (MUC5AC) is a major secreted mucin in pathogenic airways. To determine its role in mucus-related airway disorders, Muc5ac-deficient (Muc5ac^-/-) and wild-type (Muc5ac^+/+) mice were compared in bleomycin-induced pulmonary fibrosis, respiratory syncytial virus (RSV) disease, and ozone toxicity. Significantly greater inflammation and fibrosis by bleomycin were developed in Muc5ac^-/- lungs compared to Muc5ac^+/+ lungs. More severe mucous cell metaplasia in fibrotic Muc5ac^-/- lungs coincided with bronchial Muc2, Muc4, and Muc5b overexpression. Airway RSV replication was higher in Muc5ac^-/- than in Muc5ac^+/+ during early infection. RSV-caused pulmonary epithelial death, bronchial smooth muscle thickening, and syncytia formation were more severe in Muc5ac^-/- compared to Muc5ac^+/+. Nasal septal damage and subepithelial mucoserous gland enrichment by RSV were greater in Muc5ac^-/- than in Muc5ac^+/+. Ozone exposure developed more severe nasal airway injury accompanying submucosal gland hyperplasia and pulmonary proliferation in Muc5ac^-/- than in Muc5ac^+/+. Ozone caused periodic acid-Schiff-positive secretion only in Muc5ac^-/- nasal airways. Lung E-cadherin level was relatively lower in Muc5ac^-/- than in Muc5ac^+/+ basally and after bleomycin, RSV, and ozone exposure. Results indicate that MUC5AC is an essential mucosal component in acute phase airway injury protection. Subepithelial gland hyperplasia and adaptive increase of other epithelial mucins may compensate airway defense in Muc5ac^-/- mice.

Numerical analysis of nanoparticle transport and deposition in a cynomolgus monkey nasal passage

Environmental exposure to toxic agents is commonly encountered by occupational and residential populations. However, in vivo exposure data in human subjects is limited by measurement and ethical restrictions. Monkey represents a suitable surrogate for human exposure studies, but the particle transport and deposition features in monkey airways are still not well understood. As a response to this research challenge, this paper presents a virtual exposure study that numerically investigated the nanoparticle transport process through a realistic cynomolgus monkey nasal airway. Particles with size of 1 nm to 1 μm were considered and the transport process was modelled by the Lagrangian discrete phase model. Overall and local deposition as well as particle dispersion along the airway were examined by using a variety of non-dimensional parameters including combined diffusion parameter, deposition enhancement factor and particle flux enhancement factor. Consistent deposition patterns were observed in present and literature nasal models. Most particles tended to pass the nasal airway through certain spatial regions, including the middle section of the nasal valve, the lower half of the middle coronal plane, and the central regions of the choana. While naturally inhaled nanoparticles can hardly be delivered to the olfactory region as it is located apart from the mainstream with high particle flux. Research findings provide insight into nanoparticle inhalation exposure characteristics in the monkey airway and can contribute in formulating data extrapolation schemes between monkey and human airways.

Rapid maxillary expansion effects of nasal airway in children with cleft lip and palate using computational fluid dynamics

OBJECTIVES

Rapid maxillary expansion (RME) improves nasal airway ventilation in non-cleft palate children. Children with unilateral cleft lip and palate (UCLP) may have nasal obstruction and experience an increased risk of obstructive sleep apnoea. The effect of RME in UCLP children is unclear. This retrospective study evaluated RME-induced changes in ventilation parameters in children with UCLP using computational fluid dynamics.

SETTING AND SAMPLE POPULATION

Nineteen patients (10 boys, mean age 10.7 years) who required RME had cone-beam computed tomography images taken before and after RME. Twenty control participants (11 boys, mean age 11.1 years) received regular orthodontic treatment.

METHODS

Nasal airway ventilation parameters (air pressure, air velocity and airflow rate) were analysed via computational fluid dynamics, and nasal cross-sectional area (CSA) was measured.

RESULTS

Maximum pressure, velocity and nasal resistance were significantly reduced by RME in the UCLP group. Air flow rate and CSA on the cleft side significantly were increased by RME in the UCLP group.

CONCLUSIONS

In children with UCLP, increasing the quantity of airflow and CSA on the cleft side by RME substantially improved nasal ventilation.

Evaluation of Nasal Airway Volume of Operated Unilateral Cleft Lip and Palate Patients Compared With Skeletal Class III Individuals

Cleft lip and palate (CLP) patients have various problems with nasal anatomy beyond just oronasal separation. The alar base, concha, and septum are over impressed in these individuals. Additionally, skeletal class III deformity is seen. These conditions may limit nasal function. In our study, 15 unilateral patients with CLP older than 15 years (10 females, 5 males; mean age: 19.13) who had received surgery were included as the study group, and 15 participants with noncleft skeletal class III deformities were included as the control group (10 females, 5 males; mean age: 19.20). The individuals' nasal airway volumes (total/cleft side/noncleft side/control/ nasal passages) were examined and compared statistically. The results showed that the study group had significantly higher values in terms of total airway volume ( P < .05). Additionally, there were significant differences between the cleft side and noncleft side volumes, between the cleft side volumes and the volumes of the control group participants, and between the noncleft side volumes and the volumes of the control group participants ( P < .05). There was no difference between the groups in terms of nasopharyngeal ( P = .39) and nasal passage volumes ( P = .73). The results show there are some problems regarding nasal airway volume in patients with CLP, even when lip, palate, and alveolar cleft operations have been performed. The aim of this study was to evaluate differentiation of nasal airway volumes between unilateral patients with CLP and individuals with noncleft skeletal class III serving as the control group.

The Effect of Nasoalveolar Molding on Nasal Airway Anatomy: A 9-Year Follow-up of Patients With Unilateral Cleft Lip and Palate

OBJECTIVE

To determine the effects of nasoalveolar molding (NAM) on nasal airway architecture.

DESIGN

Retrospective case-control study of patients with unilateral cleft lip treated with NAM vs without NAM.

SETTING

Tertiary referral center specializing in cleft and craniofacial care. Patients, Participants, and Interventions: Thirty-six patients with complete unilateral cleft lip and alveolus: 19 with NAM therapy and 17 without NAM therapy.

MAIN OUTCOME MEASURES

Cone beam computed tomography (CBCT) scans were compared in multiple coronal sections and were evaluated for linear and angular septal deviation, inferior turbinate hypertrophy, and linear and 2-dimensional airway area.

RESULTS

There were no significant differences in linear or angular septal deviation, inferior turbinate area, linear stenosis, or airway area between NAM- and non-NAM-treated patients.

CONCLUSIONS

NAM effectively molds the external nasal cartilage and structures but may have limited effects on internal nasal structures.

Numerical simulation of two consecutive nasal respiratory cycles: toward a better understanding of nasal physiology

BACKGROUND

Computational fluid dynamic (CFD) simulations have greatly improved the understanding of nasal physiology. We postulate that simulating the entire and repeated respiratory nasal cycles, within the whole sinonasal cavities, is mandatory to gather more accurate observations and better understand airflow patterns.

METHODS

A 3-dimensional (3D) sinonasal model was constructed from a healthy adult computed tomography (CT) scan which discretized in 6.6 million cells (mean volume, 0.008 mm³ ). CFD simulations were performed with ANSYS©FluentTMv16.0.0 software with transient and turbulent airflow (k-ω model). Two respiratory cycles (8 seconds) were simulated to assess pressure, velocity, wall shear stress, and particle residence time.

RESULTS

The pressure gradients within the sinus cavities varied according to their place of connection to the main passage. Alternations in pressure gradients induced a slight pumping phenomenon close to the ostia but no movement of air was observed within the sinus cavities. Strong movements were observed within the inferior meatus during expiration contrary to the inspiration, as in the olfactory cleft at the same time. Particle residence time was longer during expiration than inspiration due to nasal valve resistance, as if the expiratory phase was preparing the next inspiratory phase. Throughout expiration, some particles remained in contact with the lower turbinates. The posterior part of the olfactory cleft was gradually filled with particles that did not leave the nose at the next respiratory cycle. This pattern increased as the respiratory cycle was repeated.

CONCLUSION

CFD is more efficient and reliable when the entire respiratory cycle is simulated and repeated to avoid losing information.

Correlation Between Nasal Epithelial Injury and In Vitro Cytotoxicity Using a Series of Small Molecule Protein Tyrosine Phosphatase 1B Inhibitors Investigated for Reversal of Leptin Resistance in Obesity

This research provides a cautionary example when evaluating changes in behavioral end points with respect to postulated pharmacologic activity. Various small molecule substrate mimetic protein tyrosine phosphatase 1B (PTP1B) inhibitors were investigated as pharmacologic agents for decreasing food consumption using intranasal (IN) dosing as a means for direct nose-to-brain delivery along the olfactory/trigeminal nerve pathways. Although food consumption was decreased in diet-induced obese (DIO) mice, nasal discharge was observed. Studies were conducted to investigate local effects on the nasal airway and to develop structure-activity relationships. Intranasal administration of PTP1B inhibitors at ≥0.03 mg/d to DIO mice produced dose-dependent injury to various cell types of the nasal epithelia. Protein tyrosine phosphatase 1B inhibitors with calculated log octanol >3.0 were the most toxic. Whereas a pharmacologically inactive analog of a PTP1B inhibitor produced nasal injury, along with decreased food consumption, the marketed IN drug ketorolac produced no lesions at the same dose of 0.3 mg/d and only minor changes at 3 mg/d. Rat skin fibroblast cells were exposed in vitro to PTP1B inhibitors, ketorolac, paraquat, and the detergent sodium dodecylbenzene sulfonate (NDS) followed by measures of cytotoxicity. The most potent PTP1B inhibitors were similar to NDS, whereas ketorolac was the least toxic compound. Cytotoxic potency in vitro was similar to in vivo. In conclusion, PTP1B inhibitors injured nasal epithelium through a mechanism independent of PTP1B inhibition and likely due to nonspecific cytotoxicity such as disruption of the cell membrane. Decreased food consumption in DIO mice was due to toxicity rather than a pharmacologic mode of action.

Reconstruction and morphometric analysis of the nasal airway of the white-tailed deer (Odocoileus virginianus) and implications regarding respiratory and olfactory airflow

Compared with other mammals (e.g., primates, rodents, and carnivores), the form and function of the ungulate nasal fossa, in particular the ethmoidal region, has been largely unexplored. Hence, the nasal anatomy of the largest prey species remains far less understood than that of their predators, rendering comparisons and evolutionary context unclear. Of the previous studies of nasal anatomy, none have investigated the detailed anatomy and functional morphology of the white-tailed deer (Odocoileus virginianus), a species that is ubiquitous throughout North and Central America and in northern regions of South America. Here, nasal form and function is quantitatively investigated in an adult white-tailed deer using high-resolution magnetic resonance imaging, combined with anatomical reconstruction and morphometric analysis techniques. The cross-sectional anatomy of the airway is shown and a three-dimensional anatomical model of the convoluted nasal fossa is reconstructed from the image data. A detailed morphometric analysis is presented that includes quantitative distributions of airway size and shape (e.g., airway perimeter, cross-sectional area, surface area) and the functional implications of these data regarding respiratory and olfactory airflow are investigated. The white-tailed deer is shown to possess a long, double scroll maxilloturbinal that occupies approximately half of the length of the nasal fossa and provides a large surface area for respiratory heat and moisture exchange. The ethmoidal region contains a convoluted arrangement of folded ethmoturbinals that appear to be morphologically distinct from the single and double scroll ethmoturbinals found in most other non-primates. This complex folding provides a large surface area in the limited space available for chemical sensing, due to the expansive maxilloturbinal. Morphologically, the white-tailed deer is shown to possess a dorsal meatus that leads to an olfactory recess, a nasal architecture that has been shown in other non-primate species to cause unique nasal airflow patterns to develop during sniffing that are optimized for odorant delivery to the sensory part of the nose. Additionally, we demonstrate that, during respiration, airflow in the nasal vestibule and the anterior maxilloturbinal region may be transitional or turbulent, in which case turbulent mixing is expected to enhance respiratory heat and moisture exchange, which could be an important contribution to thermoregulation and water conservation in the white-tailed deer.

Carbon nanotubes size classification, characterization and nasal airway deposition

Workers and researchers in the carbon nanotubes (CNT)-related industries and laboratories might be exposed to CNT aerosols while generating and handling CNT materials. From the viewpoint of occupational health, it is essential to study the deposition of CNT aerosol in the human respiratory tract to investigate the potential adverse health effects. In this study, a human nasal airway replica and two types of CNT materials were employed to conduct CNT nasal airway deposition studies. The two CNT materials were aerosolized by a nebulizer-based wet generation method, with size classified by three designated classification diameters (51, 101 and 215 nm), and then characterized individually in terms of their morphology and aerodynamic diameter. The nasal deposition experiments were carried out by delivering the size classified CNTs into the nasal airway replica in three different inspiratory flow rates. From the characterization study, it showed that the morphology of the size classified CNTs could be in a variety of complex shapes with their physical dimension much larger than their classification diameter. In addition, it was found that the aerodynamic diameters of the classified CNTs were slightly smaller than their classification diameter. The nasal deposition data acquired in this study showed that the deposition efficiency of CNTs in the nasal airway were generally less than 0.1, which implies that the majority of the CNTs inhaled into the nose could easily penetrate through the entire nasal airway and transit further down to the lower airways, possibly causing adverse health effects.

Effects of nasal cleansing and topical decongestants on patient tolerance during upper gastrointestinal endoscopy: a prospective randomized study

Adequate patient tolerance is essential for successful completion of safe endoscopic examination. Although there are many reported methods to increase patient tolerance, none of these fully resolve this problem. The aim of this study was to investigate whether relaxing the nasal airways increase patient tolerance to upper gastrointestinal endoscopy (UGE). A total of 300 patients scheduled for diagnostic UGE were randomized into three separate groups. Prior to the UGE procedure the first group was administered intranasal cortisone spray following nasal cleansing (INC). Patients in the second group were administered intranasal saline after nasal cleansing (INSP). The patients in the third group were treated with the standard endoscopic procedure alone (SEP). After the UGE procedure, both endoscopists and patients were asked to evaluate the ease of performing the procedure. Furthermore, patients who had undergone endoscopy before were asked to compare their current experience to their most recent endoscopy. Results shown that INC and INSP groups had significantly better tolerance than the SEP group. When comparing their current experience with the previous one, INC and INSP groups reported that the current experience was better.

CONCLUSIONS

Taking measures to relax the nasal airways makes breathing more comfortable and increase patient tolerance during UGE.

Septoturbinotomy

The inferior turbinates are a principal cause of nasal airway obstruction. To some extent, the bony septum (the perpendicular plate of the ethmoid) also, on occasion, contributes to that airflow obstruction. There are many excellent methods to resect or ablate the turbinates, including submucous resection and cauterization. However, some have been associated with bleeding, crusting, and the development of synechiae. In this Featured Operative Technique article, we propose 2 mechanical means to expand the nasal vault: (1) the insertion of a large and long speculum that outfractures the turbinates and also centralizes the bony septum when the handles are compressed and (2) the insertion of a large clamp, which is expanded (in reverse "nutcracker" fashion) to achieve a similar result. Mechanical dilation (expansion) of the nasal vault with the speculum or large clamp substantially improves vault diameter such that further work on the turbinates in the form of turbinectomy is seldom necessary. The nasal vault is not necessarily expanded to the maximal diameter that could be achieved with resection procedures but need not be to achieve satisfactory air flow. Septoturbinotomy is a quick and simple way to deal with inferior turbinate hypertrophy. It is a minimally invasive procedure that improves the airway in virtually all cases, such that turbinectomy is seldom employed. It can be used prophylactically on all rhinoplasty cases requiring lateral osteotomy, which potentially shrinks the nasal vault slightly.

Postoperative airway management after nasal endoscopic sinus surgery: A comparison of traditional nasal packing with nasal airway

BACKGROUND

Nasal packing after the nasal surgery can be extremely hazardous and can lead to airway complications such as dyspnea and respiratory obstruction.

OBJECTIVE

The present study aimed at comparing the traditional nasal packing with nasal airway during the immediate postoperative period in patients undergoing fibreoptic endoscopic sinus surgery (FESS) under general anaesthesia (GA) with regards to airway management.

MATERIALS AND METHODS

The study groups consisted of 90 ASA grade I and II patients aged 16 to 58 years who underwent FESS under GA. Patients were randomly assigned into three groups: Group NP, UA and Group BA of 30 patients each. At the end of surgery, Group NP patients were managed with traditional bilateral nasal packing while a presterilized 5 mm ID uncuffed ETT was cut to an appropriate size and inserted into one of the nostrils in UA and bilaterally in BA group patients. During postoperative period following parameters and variables were observed over the next 24 hours: Any respiratory distress or obstruction, pain and discomfort, oxygen saturation, heart rate, blood pressure, bleeding episode, ease of suctioning through nasal airway, anaesthesiologists and surgeons satisfaction during postoperative period, discomfort during removal of nasal airway and any fresh bleeding episode during removal of nasal airway. The data was compiled and analyzed using Chi-square test and ANOVA with post-hoc significance. Value of P < 0.05 was considered significant and P < 0.0001 as highly significant.

RESULTS

The post-op mean cardio-respiratory parameters showed significant variations among NP group (P < 0.05) and the patient of UA and BA groups while intergroup comparison between UA and BA was non-significant (P > 0.05). Pain and discomfort, bleeding episode, ease of suctioning through nasal airway, pain and bleeding during removal of nasal airway (P < 0.0001) as well as surgeons and anaesthesiologists satisfaction criteria showed significant results among the NP group as compared to UA and BA groups (P < 0.05).

CONCLUSION

The present intervention to maintain airway patency can be termed as excellent with additional benefits like ease of suctioning; oxygen supplementation and a possible haemostatic effect due to pressure on the operated site. The low cost of the modified nasal airway and easily replicable design were the standout observations of the present study.

Evaluation and reduction of nasal trauma

Nasal trauma plays a large and important role in the field of craniofacial trauma. The resulting aesthetic, structural, and functional sequelae associated with these injuries necessitate a thorough understanding of the topic. This includes an appreciation for the unique anatomic features of the region, the important aspects of the initial history and examination, nasal injury classification, and subsequent treatment timing and options. While a large body of literature has accumulated on the topic, the purpose of this article is to focus on both clinically relevant information and pearls of management. Additionally, age-specific concerns, secondary procedures, and nasal fracture grafting, will be addressed as well.

Effects of Surface Smoothness on Inertial Particle Deposition in Human Nasal Models

Computational fluid dynamics (CFD) predictions of inertial particle deposition have not compared well with data from nasal replicas due to effects of surface texture and the resolution of tomographic images. To study effects of geometric differences between CFD models and nasal replicas, nasal CFD models with different levels of surface smoothness were reconstructed from the same MRI data used to construct the nasal replica used by Kelly et al. (2004) [Aerosol Sci. Technol. 38:1063-1071]. One CFD model in particular was reconstructed without any surface smoothing to preserve the detailed topology present in the nasal replica. Steady-state inspiratory airflow and Lagrangian particle tracking were simulated using Fluent software. Particle deposition estimates from the smoother models under-predicted nasal deposition from replica casts, which was consistent with previous findings. These discrepancies were overcome by including surface artifacts that were not present in the reduced models and by plotting deposition efficiency versus the Stokes number, where the characteristic diameter was defined in terms of the pressure-flow relationship to account for changes in airflow resistance due to wall roughness. These results indicate that even slight geometric differences have significant effects on nasal deposition and that this information should be taken into account when comparing particle deposition data from CFD models with experimental data from nasal replica casts.

Induction by inhibitors of nitric oxide synthase of hyperresponsiveness in the human nasal airway

1. The effects of inhibitors of nitric oxide synthase (NOS) on the responsiveness of the human nasal airway were investigated, by measuring the nasal response to histamine and bradykinin. 2. Repeated intranasal administration of N(G)-nitro-L-arginine methyl ester (L-NAME) or N(G)-monomethyl-L-arginine (L-NMMA), 1 micromol per nostril every 30 min for 6 h, increased the nasal obstruction induced by histamine, 50 - 500 microg, and bradykinin, 200 microg per nostril. A single administration of L-NAME, 1 micromol per nostril did not induce hyperresponsiveness to histamine. 3. Pretreatment with L-arginine, 30 micromol, abolished the hyperresponsiveness to histamine caused by L-NAME, 1 micromol. Pretreatment with N(G)-nitro-D-arginine methyl ester (D-NAME), 1 micromol, did not induce hyperresponsiveness to histamine. 4. Repeated administration of L-NAME, 1 micromol, caused a significant reduction in the amount of nitric oxide measured in the nasal cavity. 5. Neither L-NMMA, 1 micromol, nor L-arginine, 30 micromol, altered the nasal hyperresponsiveness induced by platelet activating factor (PAF), 60 microg. PAF did not alter the levels of nitric oxide in the nasal cavity. 6. The results suggest that inhibition of nitric oxide synthase induces a hyperresponsiveness in the human nasal airway, and that this occurs by a mechanism different from that involved in PAF-induced hyperresponsiveness.

Involvement of kinins in hyperresponsiveness induced by platelet activating factor in the human nasal airway

1. The aim of this study was to investigate the role of kinins in the development of nasal hyperresponsiveness induced by platelet activating factor (PAF) in normal human subjects. 2. Intranasal administration of PAF, 60 micrograms, induced an increased responsiveness to histamine, 200 micrograms per nostril, 6 h later. This effect was abolished by pretreatment with the bradykinin B2 receptor antagonists icatibant and [1-adamantaneacetyl-D-Arg0,Hyp3,beta-(2-thienyl)-Al a5,8,D-Phe7]-bradykinin ([Ad]-BK), both at 200 micrograms, every 2 h following PAF administration. 3. In a separate experiment, utilizing the same protocol, nasal lavage was used to measure the release of mediators into the nasal cavity following treatment with PAF. PAF increased the levels of eosinophil cationic protein (ECP) and kinin detected in the lavage samples, compared with a saline control. The levels of these mediators were reduced by pretreatment with either icatibant or [Ad]-BK. 4. Administration of lyso-PAF, 60 micrograms intranasally, did not cause a rise in kinin or ECP levels in nasal lavage fluid. 5. Exogenous bradykinin, 500 micrograms, or a saline control, applied topically to the nasal mucosa every 30 min for 2 h, failed to cause hyperresponsiveness to histamine. 6. We conclude that bradykinin itself does not cause hyperresponsiveness, but is involved in the hyperresponsiveness induced by PAF in the human nasal airway.