Nasal Area Research Articles

Comparison of different nasal septal areas between patients with and without nasal obstruction.

Comparison of different nasal septal areas between patients with and without nasal obstruction.

The Effects of VEGF-A and GSTM1/GSTT1 Variants in the Susceptibility to the Chronic Rhinosinusitis with Nasal Polyposis: A Pilot Genetic Study.

Nasal polyps (NPs) are usually part of chronic rhinosinusitis with nasal polyposis (CRSwNP). However, the exact etiology of CRSwNP is still unknown. In addition, the suggested etiological causes are infection, allergy, and immunological disorders, among others, such as genetic predisposition. Moreover, it is also suggested that oxygen-free radicals play a vital role in the pathogenesis of nasal polyposis, and inflammatory cells produce free radicals during phagocytosis, which is the primary source of ROS, controlled by the glutathione S-transferase (GST) system. Although, vascular endothelial growth factor (VEGF) plays an important role in angiogenesis, it is closely interwoven with the mobilization of inflammatory cells. This pilot study evaluated the association between genetic variant VEGF-A (rs28357093) and GSTM1/GSTT1 deletion polymorphism in susceptibility to CRSwNP. A case-control study was conducted with 61 individuals diagnosed with CRSwNP and 100 healthy subjects. VEGF-A (rs28357093) and GSTM1/GSTT1 deletion polymorphisms were genotyped by RFLP-PCR and SYBR Green real-time PCR, respectively. Individuals with allergic rhinitis carriers with AC genotype (rs28357093) presented a 4-fold increased risk to CRSwNP (OR = 4.20, 95% CI = 1.31 to 13.50; p = 0.015). This evidence shows that the increased vascular permeability probably causes an inflamed nasal area leading to extensive edema and polyp growth. On the other hand, no association was verified for each genetic variant by inheritance models. Interestingly, the GSTT1 present genotype showed a protective effect on CRSwNP. In conclusion, additional studies that have larger groups in different geographic localizations may be useful to verify and assess the association between genetic variants and CRSwNP.

A Novel Method of Fixation and Stabilization of the Nasoendotracheal Tube for Maxillary Osteotomies: The Head Cap Technique.

To propose a novel technique of fixation and stabilization of the nasoendotracheal tube for maxillary osteotomies. The technique utilizes a flexible Portex north pole endotracheal tube size 6, elastic adhesive tape, a catheter mount and a head cap made of cloth in the fixation and stabilization of the nasoendotracheal tube for maxillary osteotomies. It is a simple method of fixation and stabilization of the nasoendotracheal tube, particularly for maxillary osteotomies that essentially eliminates distortion of the nasal, labial and perinasal areas and facilitates good nasolabial control during maxillary osteotomies. This technique is simple, safe and versatile and may be employed for maxillary osteotomies.

Impact of Intra-Retinal Fluids on Changes in Retinal Ganglion Cell and Nerve Fiber Layers in Neovascular AMD under Anti-VEGF Therapy.

Purpose: To investigate the influence of intraretinal fluid (IRF) on change in retinal nerve fiber layer (RNFL) and retinal ganglion cell layer (RGCL) and thickness in patients with naive neovascular AMD under anti-VEGF treatment. Design: post hoc analysis. Methods: 97 eyes of 83 patients on continuous therapy with intravitreal anti-vascular endothelial growth factors (anti-VEGF) and a follow-up of 24 months were included. RGCL and RNFL thickness in the perifoveal (-O), parafoveal (PF), and nasal areas and number of injections (IVI) were recorded before the first IVI as well as 1 and 2 years after initiating treatment and compared longitudinally and between groups with and without IRF. Results: The group with IRF at baseline had a higher RNFL thickness at baseline and showed a significant reduction in RNFL-PF between baseline and first and second follow-ups (p < 0.001) but not between first and second follow-ups. The group without IRF showed no significant reduction in RNFL over time. The presence of IRF was not associated with a reduction in RNFL-O or RNFL-nasal. RGCL thickness decreased significantly in both groups with and without IRF after 2 years. Number of IVIs showed no significant correlation to RNFL or RGCL after stratification for the presence of IRF. Conclusions: The presence of IRF has a significant influence on RNFL thickness at baseline as well as on its changes over time during anti-VEGF therapy. The preoperative presence of IRF should be considered when comparing changes in RNFL thickness after IVI.

Photogrammetry is a useful tool to assess the aesthetic outcome after excision and reconstruction of the nose skin tumors

BackgroundobjectivePost-oncological nasal reconstruction presents both aesthetic and functional challenges. While established methods exist for quantitatively evaluating functional results following surgery, equivalent systems for assessing aesthetic outcomes are lacking. Three-dimensional (3D) photogrammetry, already used in maxillofacial and orthodontic surgery for aesthetic evaluation, overcomes some limitations of traditional methods like direct anthropometry. However, its applicability in oncological facial reconstruction has not yet been explored. In our study, we applied the 3dMDtrio™ system for the quantitative analysis of line and surface modifications following nasal reconstruction. MethodsWe conducted a prospective observational study enrolling patients with skin neoplasms located on the nose undergoing surgical excision and reconstruction. Using the 3dMDtrio™ system, we measured the dimensions and projections of nasal surfaces and the positions of specific landmarks before and after surgery. The surface measurements were then correlated with aesthetic evaluations performed by three plastic surgeons, not involved in the procedure, using a 5-point Likert scale. ResultsWe included 33 patients with a mean age of 71 years, ranging from 40 to 94. We obtained complete documentation of all postoperative measurements for 21 patients. We observed significant changes in the positions of the landmarks post-surgery, limited to the right ala and nasion. The average nasal surface area was 4674.41 mm2 ± 477.24 mm2 before surgery and 4667.95 mm2 ± 474.12 mm2 after surgery, with no significant discrepancies. The evaluation using the Likert scale revealed an average score of 3.04 ± 0.48, with a significant negative correlation to the measured surface changes. ConclusionOur findings suggest that 3D photogrammetry can be considered a valid method for objectively assessing volumetric changes associated with post-oncological nasal reconstructive surgery.

Construction of virtual airway model to assist surgical correction of velopharyngeal insufficiency with posterior pharyngeal flap

ObjectivePosterior pharyngeal flap (PPF) is one of the most common surgical technique to correct velopharyngeal insufficiency(VPI), during which controlling the sizes of the lateral pharyngeal ports(LPP) is the key to outcomes. One innovative procedure was developed to well control the size of LPP. Materials and methods40 patients with repaired cleft palate were collected from June 2022 to August 2023. All patients were diagnosed with VPI, and treated with modified PPF surgery. For each patient, upper airway model was reconstructed, and the virtual airway model of PPF was designed. The nasal valve area was measured as it was considered to be the narrowest part of the upper airway. The upper airway resistances under different sizes of LPP was predicted through computational fluid dynamics analysis. The minimum size of each lateral pharyngeal port without obviously increase of upper airway resistance was calculated through effect of lateral pharyngeal ports’ size on upper airway resistance. Postoperative follow-up was 6–18 months, including speech outcome and respiration outcome. Resting soft palate length (RVL), effective working length of soft palate (EWL) and angle of soft palate elevation (AVL) were measured and compared according to the lateral cephalometric radiograph. ResultsThere was a linear relationship between the threshold value and nasal valve (R = 0.62). Among the forty patients, the average size of nasal valve was 47.81 mm2, the average size of the threshold value of LPP was 31.63mm2. The proportion of velopharyngeal closure competence after surgery was 95 %. Compared with the preoperative measurements, there were significantly increase of RVL, EWL and AVL (P < 0.05). There were significantly difference in the nasal obstruction symptom evaluation score in long-term follow-up compared to short-term follow-up (P < 0.05), and no one needed flap revision. There was no significant difference in nasal respiration and nasal resistance before and after surgery (P > 0.05). ConclusionWith the help of computer fluid dynamics analysis, it is possible to predict the threshold size of lateral pharyngeal port without obviously increasing upper airway resistance and reduce the risk of suffering from airway obstruction for patients undergoing PPF surgery.

An anatomical study of the nasal foramina.

The nasal foramen is located in the nasal bone and for vessels passage to supply the nasal area. This project aimed to establish reliable references for the nasal foramina for future clinical applications. The 72 dried skulls, 46 from the Division of Anatomy, University of Phayao, Thailand, and 26 from the Tulane University School of Medicine, USA, were collected and examined. The location, number, and sizes of nasal foramina were noted. The distances from each nasal foramen to the internasal suture, frontonasal suture, nasomaxillary suture, nasion, and rhinion were also recorded and used in the statistical analytical programs. The most common type of nasal foramen in all skulls was type II (one external opening) at 65.97%, followed by type I (no foramen opening) at 20.83%, type III (two external openings) at 11.11% and type IV at 2.08% (three external openings). Nasal foramen subtypes in many of the Thai and American skulls were type IIb and type IIa. The diameter of a connecting nasal foramen was significantly larger than that of a non-connecting. Results from embalmed confirmed the passage of the external nasal artery through the nasal cavity. The study shows no significant difference in nasal foramen morphometry between Thai and American. It illustrates recent data on type and subtype classifications and the location of a vascular passage through the nasal foramen. This is the first study of NF variations and their respective classifications.

Changes in three-dimensional nasal morphology according to the direction of maxillary movement during Le Fort I osteotomy

Le Fort I (LFI) osteotomy is commonly performed by orthognathic surgeons; however, postoperative changes in nasolabial morphology are of concern. Several factors influence such changes, but it is difficult to accurately predict the postoperative results. This study evaluated the three-dimensional (3D) morphological changes in the nasal region according to the different directions of maxillary movement during LFI osteotomy. Forty-one patients who underwent LFI osteotomies were included. All patients were divided into maxilla-up (Group U: 20 patients) and maxilla-forward (Group F: 21 patients) groups. Soft tissue morphologies were determined preoperatively and 3 or 6 months postoperatively using an optical 3D scanner. All datasets were evaluated in terms of volume changes in nine subregions and changes in linear measurements around the nasal area. Both groups exhibited increased nasal volumes after surgery in the order of the three upper, three central, and three lower subregions. The change in volume of the central nasal region tended to be greater in Group U than that in Group F. We evaluated 3D morphological changes in the nasal region according to the direction of maxillary movement during LFI osteotomy. Group U exhibited a large change in the volume of the central nasal region.

Investigation of choroidal thickness and choroidal vascularity index in ocular rosacea patients according to skin subtypes

BackgroundTo compare the choroidal thickness (CT) and choroidal vascularity index (CVI) values in ocular rosacea (OR) patients across skin subtypes of the disease and healthy controls. MethodsThis prospective study included 90 eyes of 90 mild-moderate OR patients with different skin subtypes (30 phymatous, 30 papulopustular and 30 erythematotelangiectatic) and 30 eyes of 30 age-gender matched healthy volunteers. After obtaining the enhanced depth imaging optical coherence tomography images, the CT was measured at subfoveal, 1500 μm nasal and 1500 μm temporal to the fovea, and the CVI was calculated using Image J software in the subfoveal, nasal and temporal areas. ResultsThere was no CT significant difference between OR patients and healthy controls in all regions (p > 0.05). CVI values of OR patients were found to be significantly lower in the subfoveal, nasal and temporal regions compared to healthy controls (p = 0.02, p = 0.01, p = 0.01, respectively). No CT difference was detected between the subtypes and healthy controls in all regions (p > 0.05). Subfoveal-CVI was significantly lower in the phymatous subtype than the other subtypes and controls (p < 0.05), while nasal and temporal-CVI were significantly lower in the phymatous and papulopustular subtypes than the erythematotelangiectatic subtype and controls. ConclusionOur study demonstrated no difference between rosacea skin types and healthy controls in terms of CT. Phymatous and papulopustular subtypes were more likely to be affected by chronic inflammation with having lower CVI in most of the regions. Further studies are needed to investigate the association of inflammatory factors with CVI in OR.

Lateral Globe Exposure Associated With Graves Upper Eyelid Retraction: The Influence of the Superior Complex Enlargement and Proptosis.

To investigate the association of the lateral exposure of the globe with proptosis and the enlargement of the superior complex (SC) (levator palpebrae superioris muscle + superior rectus muscle) in patients with Graves upper eyelid retraction. Twenty-eight patients with upper lid retraction secondary to Graves orbitopathy and 28 controls matched by age and gender participated in the study. The variables exophthalmometry, margin-reflex distance 1, and upper lid fissure temporal and nasal areas were assessed. Coronal CT scans were evaluated for the measurement of the SC area. A 5% level of significance was assumed for analysis. Abnormal temporal nasal area differences (T-N), defined as values above the superior limit of the control distribution (15.58mm2) were detected in 18 patients. Multiple regression analysis showed a significant correlation of abnormal temporo-nasal asymmetries with the SC area and the proptosis (T-N = -6.7 + 0.62* proptosis + 12.3 SC area, R2 = 0.37; p = 0.003). The etiology of the enhanced lateral globe exposure is not unifactorial. SC enlargement and, to a lesser extent, proptosis are important factors correlated to lateral globe exposure.

Vascular changes of the peripapillary choroidal area in the thyroid orbitopathy.

The aim of this study was to investigate the peripapillary choroidal vascular changes in thyroid orbitopathy (TO). The study included 20 eyes of 10 patients with active TO (aTO), 30 eyes of 15 patients with inactive TO (inaTO) and 30 eyes of 30 healthy subjects. The peripapillary choroidal vascular change was assessed with peripapillary choroidal vascular index (pCVI), peripapillary choroidal luminal area (pLA), peripapillary choroidal stromal area (pSA), peripapillary total choroidal area (pTCA). Compared to the control group, there was a reduction in the nasal and temporal areas of pCVI in both the aTO and inaTO groups (aTO vs control: nasal p = 0.001 and temporal p = 0.004; inaTO vs control: nasal p = 0.007 and temporal p < 0.001), while the inferior area was lower only in the inaTO group (p = 0.001). Compared to the other groups, the inaTO group exhibited a decrease pSA (vs aTO: total p = 0.004, inferior p = 0.02 and vs control: total p = 0.01, inferior p = 0.03), pLA (vs aTO: total p = 0.02, inferior p = 0.02, temporal p < 0.001 and vs control: total p = 0.002, inferior p < 0.001, temporal p < 0.001) and pTCA (vs aTO: total p = 0.009, inferior p = 0.01, temporal p < 0.001 and vs control: total p = 0.003, inferior p = 0.001, temporal p < 0.001). The horizontal area (nasal and temporal area) of the peripapillary choroidal vascular structure may be more sensitive than the vertical area in TO patients. The first affected quadrant of RPC-VD in the active TO may be the inferior quadrant. Structural or vascular choroidal changes may occur during the chronic or post-active phase of the disease.

Improvement of corneal epithelial damage after switching from the concomitant use of brinzolamide and brimonidine to a brinzolamide/brimonidine fixed-dose combination.

To assess the effectiveness of switching from the concomitant use of brinzolamide 1% (BZM) and brimonidine 0.1% (BMD) to a BZM/BMD fixed-dose combination (BBFC) for the reduction of corneal epithelial damage. Retrospective cohort study. This study involved 52 eyes of 52 glaucoma patients (26 women, 26 men; mean age: 67.0 ± 14.0 years) followed for more than 3 months after being switched from concomitant BZM and BMD to BBFC. Superficial punctate keratitis (SPK) was assessed by fluorescein staining according to the National Eye Institute classification, with the cornea divided into 5 areas: center, superior, nasal, temporal, and inferior. SPK density was graded as 0 (no SPK), 1 (separate SPK), 2 (moderately dense SPK), and 3 (high SPK with overlapping lesions). SPK scores and intraocular pressure (IOP) at pre switching to BBFC (pre-BBFC) and at 3-months post switching to BBFC (post-BBFC) were then compared using the Wilcoxon signed-rank test. At pre-BBFC and post-BBFC, respectively, mean IOP was 12.4 ± 2.5 and 12.4 ± 2.7 mmHg, thus illustrating no significant difference in IOP between pre and post switch (p = 0.924), and the mean SPK score for center, superior, nasal, temporal, and inferior was 0.06 ± 0.24, 0.04 ± 0.19, 0.52 ± 0.67, 0.15 ± 0.36, and 0.92 ± 0.74, and 0.04 ± 0.19, 0.02 ± 0.14, 0.37 ± 0.56, 0.04 ± 0.19, and 0.75 ± 0.62, thus clearly showing a significant reduction in SPK scores for the nasal, temporal, and inferior areas at post-BBFC compared to those at pre-BBFC (p < 0.05). Our findings reveal that compared with the concomitant use of BZM and BMD, BBFC is effective in reducing corneal epithelial damage.

Exploring Progression and Differences in Facial Asymmetry for Hemifacial Microsomia and Isolated Microtia: Insights from Extensive 3D Analysis.

Aiming to measure and compare asymmetry of facial hard and soft tissues in patients with HFM and isolated microtia, examining how it evolves. This cross-sectional study assessed facial asymmetry in male East Asian patients aged 5-12 diagnosed with unilateral hemifacial microsomia (Pruzansky-Kaban types I and IIA) or isolated microtia. Using 3D imaging of computed tomography scans, it measured root-mean-square (RMS) values for surface deviations across facial regions. Statistical analyses explored differences between conditions and the relationship of age with facial asymmetry. A total of 120 patients were categorized into four groups by condition (HFM or isolated microtia) and age (5-7 and 8-12 years). Patients with HFM exhibited the greatest asymmetry in the lower cheek, while those with isolated microtia showed primarily upper face asymmetry. Significant differences, except in the forehead and nasal soft tissue, were noted between the groups across age categories. Notable distinctions in hard tissue were found between age groups in the nasal and mid-cheek areas for patients with HFM (median RMS (mm) 0.9 vs. 1.1, P = 0.02; 1.5 vs. 1.7, P = 0.03) and in the nasal and upper lip areas for patients with isolated microtia (median RMS (mm) 0.8 vs. 0.9, P =0.002; 0.8 vs. 1.0, P = 0.002). Besides these areas for HFM, no significant age-asymmetry correlation was detected. Significant differences in facial asymmetry were observed between HFM and isolated microtia, with the asymmetry in specific area evolving over time. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Objective Parameters for Evaluating Internal Nasal Valve Compromise: Beyond the Angle Perspective.

Nasal valve surgery for internal nasal valve (INV) compromise has become increasingly popular. However, this rise in popularity has sparked debates regarding its indications and disputes over insurance coverage, primarily due to the lack of a gold-standard evaluation method. Therefore, we aimed to identify objective parameters for the INV compromise. We analyzed 186 INVs in 93 patients who underwent nasal valve surgery. The data comprised facial computed tomography (CT) images, acoustic rhinometry, the modified Cottle test, and symptom scores. Patients were categorized based on their symptoms and the. of the modified Cottle test. We measured the INV angle, area, volume, lateral wall thickness, septal angle, and nasal bone area using CT. The compromised INV group, characterized by nasal obstruction with a positive modified Cottle test, exhibited smaller INV areas in both coronal and axial views, reduced INV volume in the axial view, and a thinner lateral wall in the coronal view (all P<0.05). Acoustic rhinometry indicated a smaller minimal cross-sectional area and volume in the compromised INV group (both P<0.001). Regression analysis demonstrated significant associations between a compromised INV and reduced INV area on the axial view, as well as the minimal cross-sectional area measured by acoustic rhinometry. Relying solely on the INV angle in CT scans has limitations in assessing compromised INV. Alternatively, the INV area on axial CT scans and the minimal cross-sectional area measured by acoustic rhinometry may serve as objective parameters for evaluating INV compromise.

Three-Month Comprehensive Outcomes of Topography-Guided LASIK Versus Keratorefractive Lenticule Extraction (KLEx): A Prospective Contralateral Study.

The aim of this study was to compare outcomes of topography-guided laser-assisted in situ keratomileusis (TG-LASIK) and small incision lenticule extraction (SMILE®) for correcting myopia and myopic astigmatism. In this prospective, randomized contralateral study, 34 patients (68 eyes) received TG-LASIK in one eye, and SMILE in their fellow eye. Efficacy, safety, predictability, higher-order aberrations, corneal tomography, biomechanics, and patient-reported outcomes (PROs) were assessed preoperatively and up to 3months postoperatively. Both platforms showed comparable efficacy at 3months (TG-LASIK 1.08 ± 0.19; SMILE 0.98 ± 0.17, p = 0.055). However, TG-LASIK demonstrated quicker visual recovery, with 63% and 89% achieving uncorrected distance visual acuity (UDVA) of 20/16 or better at 1day and 1week, respectively, compared to SMILE (34% and 63%; p < 0.05). Safety index at 3months did not significantly differ between TG-LASIK and SMILE (p = 0.223). TG-LASIK and SMILE had 44% and 56% of eyes within 0.13D of spherical equivalent (SEQ) target, respectively. SMILE induced more total higher-order aberrations (HOAs), vertical coma, and oblique trefoil than TG-LASIK at 3months (p < 0.05). Both platforms showed similar increases in epithelial remodeling, but SMILE induced thicker epithelium than TG-LASIK at the 7.0-mm nasal zonal area. No significant differences were found in corneal hysteresis (CH) or corneal resistance factor (CRF) at 3months (p > 0.05). Reported symptoms of glare, halos, rings, starbursts, or dry eye did not significantly differ between groups at 3months (p > 0.05). Overall, 59% of patients preferred their TG-LASIK treated eye at 1month, but 65% of patients had no specific eye preference at 3months. TG-LASIK and SMILE demonstrate excellent and comparable efficacy, safety, and predictability at 3months, but TG-LASIK offers faster postoperative visual recovery at 1day and 1week. TG-LASIK induces fewer HOAs than SMILE, but both procedures affect corneal biomechanics similarly. ClincialTrials.gov identifier, NCT05611294.

Association Between Gut and Nasal Microbiota and Allergic Rhinitis: A Systematic Review.

Allergic rhinitis is a chronic non-infectious inflammation of the nasal mucosa mediated by specific IgE. Recently, the human microbiome has drawn broad interest as a potential new target for treating this condition. This paper succinctly summarizes the main findings of 17 eligible studies published by February 2024, involving 1044 allergic rhinitis patients and 954 healthy controls from 5 countries. These studies examine differences in the human microbiome across important mucosal interfaces, including the nasal and intestinal areas, between patients and controls. Overall, findings suggest variations in the gut microbiota between allergic rhinitis patients and healthy individuals, although the specific bacterial taxa that significantly changed were not always consistent across studies. Due to the limited scope of existing research and patient coverage, the relationship between the nasal microbiome and allergic rhinitis remains inconclusive. The article discusses the potential immune-regulating role of the gut microbiome in allergic rhinitis. Further well-designed clinical trials with large-scale recruitment of allergic rhinitis patients are encouraged.

Driver drowsiness is associated with altered facial thermal patterns: Machine learning insights from a thermal imaging approach

Driver drowsiness is a significant factor in road accidents. Thermal imaging has emerged as an effective tool for detecting drowsiness by enabling the analysis of facial thermal patterns. However, it is not clear which facial areas are most affected and correlate most strongly with drowsiness. This study examines the variations and importance of various facial areas and proposes an approach for detecting driver drowsiness. Twenty participants underwent tests in a driving simulator, and temperature changes in various facial regions were measured. The random forest method was employed to evaluate the importance of each facial region. The results revealed that temperature changes in the nasal area exhibited the highest value, while the eyes had the most correlated changes with drowsiness. Furthermore, drowsiness was classified with an accuracy of 88 % utilizing thermal variations in the facial region identified as the most important regions by the random forest feature importance model. These findings provide a comprehensive overview of facial thermal imaging for detecting driver drowsiness and introduce eye temperature as a novel and effective measure for investigating cognitive activities.

Is the mouse nose a miniature version of a rat nose? A computational comparative study

Background and objectiveAlthough the mouse is a widely used animal model in biomedical research, there are few published studies on its nasal aerodynamics, potentially due to its small size. It is not appropriate to assume that mice and rats' nasal structure and airflow characteristics are the same because the ratio of nasal surface area to nasal volume and body weight is much higher in a mouse than in a rat. The aim of this work is to use anatomically accurate image-based computational fluid dynamic modeling to quantitatively reveal the characteristics of mouse nasal airflow and mass transport that haven't been detailed before and find key differences to that of rat nose, which will deepen our understanding of the mouse's physiological functions. MethodsWe created an anatomically accurate 3D computational nasal model of a B6 mouse using postmortem high-resolution micro-CT scans and simulated the airflow distribution and odor transport patterns under restful breathing conditions. The deposition pattern of airborne particles was also simulated and validated against experimental data. In addition, we calculated the gas chromatograph efficiency of odor transport in the mouse employing the theoretical plate concept and compared it with previous studies involving cat and rat models. ResultsSimilar to the published rat model, respiratory and olfactory flow regimes are clearly separated in the mouse nasal cavity. A high-speed dorsal medial (DM) stream was observed, which enhances the delivery speed and efficiency of odor to the ethmoid (olfactory) recess (ER). The DM stream split into axial and secondary paths in the ER. However, the secondary flow in the mouse is less extensive than in the rat. The gas chromatograph efficiency calculations suggest that the rat may possess a moderately higher odorant transport efficiency than that of the mouse due to its more complex ethmoid recess structure and extensive secondary flow. However, the mouse's nasal structure seems to adapt better to varying airflow velocity. ConclusionsDue to the inherent structural disparities, the rat and mouse models exhibit moderate differences in airflow and mass transport patterns, potentially impacting their olfaction and other behavioral habits.

Corneal Epithelial Cell Density Is Reduced in Young Adults With Conjunctival Ultraviolet Autofluorescence.

The aim of this study was to investigate the effects of chronic ultraviolet (UV) radiation exposure on the corneal microstructure using conjunctival UV autofluorescence (CUVAF) as a marker of exposure. Young healthy adults aged 18 to 35 years were recruited. Participant's demographics and sun exposure behavior were recorded using questionnaires. Images of the bulbar conjunctiva from the right eye were captured and analyzed for the CUVAF area. Corneal microstructure was assessed by in vivo confocal microscopy and anterior segment optical coherence tomography. The presence of palisades of Vogt in all 4 limbal quadrants was recorded. CUVAF was observed in 31 of 52 eyes (60%), with a mean (±SD) nasal, temporal, and total CUVAF area of 5.39 ± 4.16 mm 2 , 4.29 ± 4.27 mm 2 , and 9.67 ± 7.01 mm 2 , respectively. Individuals with CUVAF were significantly more likely to report undertaking moderate-intensity to high-intensity outdoor exercise ( P = 0.021). Individuals with CUVAF were less likely to have visible nasal and temporal palisades of Vogt ( P = 0.011). Corneal basal cell densities anterior to the nerve whorl ( P < 0.001) and nasally ( P = 0.005) were lower in individuals with CUVAF. Wing cell density anterior to the nerve whorl was lower in individuals with CUVAF ( P = 0.011). No significant changes in the central and limbal corneal epithelial thickness were observed. Significant reductions in corneal epithelial cell density were observed in individuals with CUVAF, a biomarker of chronic UV exposure. This observation suggests that chronic UV exposure is damaging to the corneal microstructure.

Comparative Analysis of Micrometer-Sized Particle Deposition in the Olfactory Regions of Adult and Pediatric Nasal Cavities: A Computational Study.

Direct nose-to-brain drug delivery, a promising approach for treating neurological disorders, faces challenges due to anatomical variations between adults and children. This study aims to investigate the spatial particle deposition of micron-sized particles in the nasal cavity among adult and pediatric subjects. This study focuses on the olfactory region considering the effect of intrasubject parameters and particle properties. Two child and two adult nose models were developed based on computed tomography (CT) images, in which the olfactory region of the four nasal cavity models comprises 7% to 10% of the total nasal cavity area. Computational Fluid Dynamics (CFD) coupled with a discrete phase model (DPM) was implemented to simulate the particle transport and deposition. To study the deposition of micrometer-sized drugs in the human nasal cavity during a seated posture, particles with diameters ranging from 1 to 100 μm were considered under a flow rate of 15 LPM. The nasal cavity area of adults is approximately 1.2 to 2 times larger than that of children. The results show that the regional deposition fraction of the olfactory region in all subjects was meager for 1-100 µm particles, with the highest deposition fraction of 5.7%. The deposition fraction of the whole nasal cavity increased with the increasing particle size. Crucially, we identified a correlation between regional deposition distribution and nasal cavity geometry, offering valuable insights for optimizing intranasal drug delivery.