Gender Differences in Ethmoid Sinus Morphology

Gender Differences in Ethmoid Sinus Morphology | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Gender Differences in Ethmoid Sinus Morphology Chi-Pin Hsu, Chih-Feng Lin, Chih-Chi Yang, Jeng-Ywan Jeng, Chang-Hung Huang This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4199542/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 10 You are reading this latest preprint version Abstract Background The ethmoid sinus (ES) is a three-dimensional (3D) complex structure, a clear understanding of the ES anatomy is helpful to plan intranasal surgery. However, most prior studies use 2D measurements, which may not accurately depict the 3D structure. The current study measured the gender differences in ES morphology based on 3D reconstruction of computed tomography (CT) images. Methods The 3D models were reconstructed using CT images. Twenty-one males and 15 females were enrolled in the study. The ES dimensions, including width, height and aspect ratio (AR) of each cutting-plane section, were measured at 10% increments along with the anteroposterior axis of the ES. The gender differences in the above parameters were further evaluated by an independent t -test. Results The width of the ES for males is 12.0±2.1mm, which was significantly greater than that in females (10.0±2.1 mm). The average height for males is 18.4±3.5mm, and 18.2±3.4mm for females. The AR of female (male) is around 0.56 (0.63) for the anterior ES and 0.66 (0.75) for the posterior. There are significant differences between genders in the parameters of width and AR ( p <0.05) Conclusion This study found that the AR greatly varies along the length of ES, indicating that the cross-section of the ES in the anterior is closer to an elliptical shape and turns closer to a circular shape near its posterior. There is a significant difference between genders in width and AR. The results would be helpful to know the complex anatomic details of the ethmoid sinus. Ethmoid sinus Morphometrical analysis 3D reconstruction Computed Tomography Gender difference Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Introduction The nasal sinuses are an anatomically complex, interconnected system with air pockets that are connected to the nasal passages by cavities. The morphology of the nasal sinus varies significantly and is influenced by genetic diseases, infectious diseases, or environmental conditions [1-5]. Modern medical imaging technology allows the detection of sinus lesions, which improves the accuracy of measurement and allows appropriate planning for intranasal surgery [6,7]. The ES is a common site for functional endoscopic sinus surgery (FESS) [8]. Its size and appearance are important indicators during FESS surgery. Many morphometrical studies used 2D plane image technology to depict the 3D ES anatomy [8-14]. Those results differed between studies and the average length of the ES ranged from 37.2±4.6 to 41.4±4.0 mm, and the width ranged from 11.6±2.2 to 16.7±3.8 mm [8-14]. The errors may raise owing to the tilting of the head during scanning or slice non-orthogonal with sinus if using 2D measures (Fig 1A). Moreover, prior studies analyzing the data in human skeleton system [15-19] have confirmed that the measured data from 3D reconstruction measurement results are more consistent and accurate than that from 2D measures. Some morphological studies have reported racial and gender differences in sinus [8,14-16]. One recent study showed that Chinese ES was about 16% wider than examples from another study [13]. The study reported that a Chinese male ES was around 13% higher than that of a female [13], but the opposite is true for Africans [8]. These studies showed that the anatomy of the sinus was affected by factors such as race, gender or the measurement method. Most of the data for previous studies was collected using 2D CT images. Although other studies used 3D measure strategies but they only calculated the volume [20,21] or just used to classify the shape classifications [22,23]. Three-dimensional data for the ES structure has yet to be collected. This study aimed to measure the 3D structure of the ES by using a CT image reconstruction model. This model reconstruction and measurement method has been approved in the research team’s prior study when measuring the lower extremity of the human body [24]. The outline at each cutting-plane section of the ES was measured to determine the entire structure of the ES. The ES geometry for male and female subjects was also compared to determine any difference between genders in Asian populations. It is hypothesized that the ES of male subjects is significantly larger than that of females. Materials and Methods This study included subjects from patients with nasolacrimal duct stenosis for dacryocystorhinostomy, pituitary or skull base tumors who underwent surgery, and those who complained of olfactory dysfunction but demonstrated normal sinonasal findings on their computed tomography scans. Patients with previous sinonasal surgery for anatomical or inflammatory conditions, head and neck cancer received radiotherapy, trauma, orthognathic surgery, or congenital sinonasal disorders were excluded from the enrollment. A total of 36 subjects (21 males and 15 females) were included in the study which was approved by the Institutional Review Board (201912187RINA). The average age of the subjects is 55.4 years (21~99): a mean of 52.0 years old for males and 59.2 for females. All subjects had intact sinuses on both sides so a total of 72 sinus data points (42 male and 30 female data) were analyzed. The measurement process for this study is shown in Fig. 1. CT scans were performed using a multi-slice CT machine (Sensation 16 SLICE, SIEMENS, Memphis, USA) with a 1mm slice thickness (120 Kv, 20 mA). Image segmentation and reconstruction used OOOPDS (Main Orthopedic Biotechnology Co., Ltd., Taichung City, Taiwan). The image was first correctly oriented using the criteria for the Frankfurt plane [25]. The ethmoid sinus (ES) level and the coordinates were then defined (Fig.1A). The sinus cavity region is used to define the appearance of the sinus. The sinus was then segmented into the sphenoid sinus (SS), the frontal sinus (FS), the maxillary sinus (MS), the ethmoid sinus (ES) and the nasal cavity (Fig.1B). The sinus cavity is reconstructed as a 3D model, and a boundary surface is defined by the standard anatomy of the ES (Fig.1C-E). This study focuses on the standard anatomical narrative of the ES area [26]. The ES model then removed the area outside the boundary surface and constructs cutting plane increments of 10% in the anterior-posterior (AP) direction for the remaining ES models (Fig.1F). The cutting plane and the overlapping position of the ES model is the section contour of the ES. The total length of the ES and the width and height of each section were measured and the differences between genders were further determined (Fig.1F). Definition of the coordinate system and the correct orientation of the images Different image orientations produce errors in measurement so the coordinate system is defined initially. The coordinate definition uses the Frankfurt plane [25]. The cranial base in the sagittal view is used as the horizontal basis to correct the Y-axis rotation of the model (Fig.2A). The Z-axis rotation is corrected using the nasal septum in the axial view as the vertical basis (Fig.2B). The X-axis rotation of the model is then corrected using the cranial base and the nasal septum in the coronal view as the vertical and horizontal basis (Fig.2C). Defining and constructing ES model and boundaries The sphenoid, frontal, maxillary, ES and nasal cavities are segmented and reconstructed for this study (Fig. 1B and 1C). The correctness of the image segmentation was confirmed by two ENT surgeons who are co-authors of this study (Lin CF and Yang CC). The boundaries of the ES were defined based on standard anatomical descriptions (Fig. 1D) [26]. The upper boundary is defined as the cranial base, the outer boundary is periorbital and the inner boundary is middle turbinate. The boundary of each section is reconstructed as a boundary surface of the 3D model (Fig.1E). The irrelevant area beyond the boundary surface is removed, so the remaining area of ES is the target for subsequent measurements (Fig. 1F). All cavities of the sinuses are reconstructed as 3D models and the correctness of the division was verified by two coauthors to minimize the error in boundary definition. Measurement of the ethmoid sinus Reverse engineering software RevCAD V1.50 (PouYuen Tech Corp., Taoyuan, Taiwan) was used to create cutting planes (Fig.1F). In order to analyze the complex anatomical appearance of ES objectively, the total length of the ES is used as a benchmark and the starting plane is through the frontmost point of the ES and perpendicular to the Y axis. Cutting planes are established at every 10% increment of the total length. The vertical distance between the 0% and 100% cutting planes is defined as the ES length (L) (Fig.1F). The intersection of the cutting planes and ES are defined as cutting points. The closed curve is calculated using a B-spline curve fitting algorithm with the cutting points (Fig. 1G)[27]. The distance from maximum Z i to minimum Z i for the closed curve is the height (H i ) of this ES section (Fig.1H), where i =0%, 10%, 20%,…, 100%. The distance from maximum Y i to minimum Y i for the closed curve is the width (W i ) of the ES section (Fig.1H). For this study, the aspect ratio (AR) of width to height for each ES section is defined as AR i = W i / H i , AR i and is used to determine the change in shape for each section of the chamber, which clearly defines the anatomy. Statistical analysis To ensure that the data is normally distributed, the Kolmogorov-Smirnov test was used and proven for p > 0.05 in parametric statistics. G-power 3.1 was used for a post hoc power analysis of gender differences, with α = 0.05, and the calculated statistical power is 97%. Statistical data is analyzed using SPSS (version 20, SPSS Inc., Chicago, IL, USA) and independent t -tests are used to determine the significance of gender differences. A value of p < 0.05 indicates statistical significance. Results The average ES length for the male group is 40.1±5.0 mm and for the female group is 41.3±5.0 mm. There is no significant difference between genders ( p =0.140) (Table 1). Figure 4A shows the average width of each section. The maximum width of the male ES is W 60 =12.0 ± 2.1 mm and the maximum width of the female ES is W 80 =10.0 ± 2.1 mm. The male ES is significantly wider than the female ES. Except for W 10 ( p =0.064), there is a statistically significant difference in most of the sections ( p< 0.05). Figure 4B shows the average height of each section. The male and female ES has a maximum height at H 40 (18.4±3.5 mm and 18.2±3.4 mm). The maximum height for the male group is slightly greater than that for the female group for all ES heights, but the only significant difference is at H 60 ( p =0.045) and H 80 ( p =0.048). The largest and smallest aspect ratio (AR) values for the male group are AR 90 =0.9±0.5 and AR 20 =0.6±0.2, respectively (Fig. 4A), and for the female group, these values are AR 90 =0.8±0.2 and AR 30 =0.5±0.1, respectively. The AR values for the male group are larger than those for the female group. There is a significant difference from AR 40 to AR 70 but the AR value for the anterior section (AR 10 - AR 50 ) for the male group is 19.4% smaller on average than that for the posterior section (AR 50 - AR 90 ). The anterior section for the female group is 18.3% smaller on average than the AR value for the posterior section. There are significant differences between AR 10 vs. AR 90 , AR 20 vs. AR 80 , AR 30 vs. AR 70 , and AR 40 vs. AR 60 . The AR for the left ES is slightly greater than the value for the right side (Fig. 4B) but there is no significant difference ( p =0.26). The AR of the cross-section is about 0.6for the anterior sections, so the cross-section of the ES in the anterior sections is close to an elliptical cylinder (Fig. 5A). However, the AR valuesfor the cross-section in the posterior part are about 0.7-0.9, so the cross-sections in the posterior parts is almost circular. Discussion The ES is the most anatomically complex part of the nasal sinuses. It is created by the ethmoid bone, forming multiple pyramidal air cells. For this study, the 3D ES model is reconstructed to measure the detail of the ES section. This study allows a more accurate description of the anatomy of the ES than the 2D measurements that are used by other studies [8-14]. Most studies use 2D or planar images to measure the length of ES [8-14]. Those studies use one image that is the uppermost edge of the optical canal in several axial-view images and measure the length of ES using this image. However, the orientation of the 2D image is affected by the subject’s posture during the CT scan (Fig. 2). In this study, subjects used a head fixation device when taking CT scans. However, the average orientation difference between the original CT and the corrected model is 9.1°±10.6, 1.8°±2.4 and 2.1°±2.7 in the sagittal, axial and coronal plane (Fig. 6). Especially in the sagittal plane, the orientation difference is 3.3 times and 4.2 times than the axial and coronal plane. So, the CT images are not orthogonal to the landmarks of the ES structure. The 2D or planar measurement method produces more errors than 3D reconstruction measurement methods [15-19,21]. The orientation of the 3D model is corrected for this study using the standard for the Frankfurt plane, so all models are set using the same coordinate. One study [13] reported the maximum respective ES length for male and female groups as 37.6±3.4 mm and 37.0±4.13 mm using 2D measurement. The measurements of the ES using the 3D method of this study are much longer than those that are obtained using 2D measurement (Table 1). The height of ES is an important measure; however, more data is needed for 2D measurement studies [8-14]. This study used a complete sinus model so the anatomical location and identification of ES regions is much clearer. The height of each section of the ES and the width of the ES were measured continuously at every 10% interval of the ES length (Fig. 1H and Fig. 4). The results showed that the average height of the ES for a Chinese male was 13.7±6.6 mm and for a Chinese female is 13.0±6.2 mm. No significant difference in the height of the ES was found for male and female groups ( p >0.05) but there is a statistically significant difference in width. The average width of the ES for a Chinese male was 9.1±4.1mm and for a Chinese female was 7.8±3.4 mm. The male ES is about 20.0% larger than that of the female. The difference between the measurement results for this study and those of other studies, in terms of length, width and height are about -47%‒3%, -14%‒78% and 12%‒64%, respectively (Table 1). The results showed that there is a significant difference between the results of this study and the measurements for other studies, possibly because of the difference between the 3D and 2D measurement methods, the measurement location or ethnic differences. The shape of an ES section is defined using the aspect ratio of the width to the height of the ES. If AR=1, the shape is a circle and ifAR<1, it is closer to an ellipse. The results of this study showed that the average shape of ES is closer to an ellipse, especially for the anterior ES (AR 10 -AR 50 ), for which the AR value is about 0.60, and the posterior ES (AR 50 -AR 90 ), for which the AR value is about 0.74 (Fig.5A). The aspect ratio for the end of the ES (AR 80 -AR 90 ) is about 0.9, so posterior ES is approximately like a circle in the final section. As for the AR value in male ES is significantly greater than that for a female, particularly in the range of AR 40 - AR 70 . A large number of Asian people suffer from chronic sinusitis [28,29] and may require a stent to prevent restenosis after ES surgery [30-32]. Determining the 3D structure of an ES cavity allows more accurate planning for nasal surgery. The current ES stent has a circular section after it is deployed [30], but the anterior part should be elliptical and the posterior part should be almost circular. So, it does not fit the cavity shape. Our previous biomechanics study [33] analyzed the contact behavior of a nasal stent that was deployed to the ES cavity and showed that there was a significant rise of contact stress on the inside of the ES and a part of the stent material has caused permanent plastic deformation possibly due to mismatch between the stent and nasal cavity. If the shape of the implant deviates too much from the shape of the ES, excessive stress can occur and the ES can become loose [33]. The design of a commercial stent should ensure optimal stent-ES contact in the ES cavity. The section curve and the aspect ratio of the ES can provide helpful information for the improvement of the nasal device (Fig. 5B). This study has some limitations that should be mentioned here. First, the subject number is not big enough. The current study primarily developed a new measurement method to obtain 3D results in this stage and we will keep enrolling more data in the near future. Second, in order to obtain the most typical measurement data, this study only included normal anatomy cases. However, the morphology of ES may differ from the typical one after FESS. Third, the standard anatomy of the ES defined the upper (cranial base), outer (periorbital), and inner boundary (middle turbinate), but not inferior boundary [26]. Therefore, this study defined the inferior boundary by the lowest point of section curve (Fig.1 G). Finally, there are multiple ways to demarcate and measure the morphology but it is difficult to define the boundaries of these complex air sacs. In addition to the limitations mentioned above, the current study has put new information to know the continuous change of the ES. Conclusion This three-dimensional morphometrical measurement showed that the sinus cavity constantly changes from anterior to posterior. The male ES is significantly wider than the female. The aspect ratio result indicates that the anterior ES is closer to an elliptical shape, but the shape is similar to a circle in the posterior section instead. The aspect ratio of the middle section of a male ES is significantly greater than that of a female. Declarations Authors’ Contributions: Chi-Pin Hsu: Conceived the study design, helped to draft the manuscript and supervised the study, analyzed and interpreted the data. Chih-Feng Lin: Acquired the data, analyzed and interpreted the data, drafted the manuscript Chih-Chi Yang: Acquired, analyzed and interpreted the data Jeng-Ywan Jeng: Helped to draft the manuscript and supervised the study Chang-Hung Huang: Conceived the study design, helped to interpreted the data, draft the manuscript and supervised the study Ethics approval This study is approved by the Institutional Review Board of National Taiwan University Hospital (IRB number: 201912187RINA). Because of the retrospective nature of the study, the requirement for informed consent was waived. The study was performed in accordance with the Declaration of Helsinki. All methods were carried out in accordance with relevant guidelines and regulations. Acknowledgments We are also grateful to the National Science and Technology Council (111-2221-E-195 -003 -MY3) for providing financial support for our research. Their generous funding allowed us to conduct our study and complete our work. Disclosures Competing interests: The authors Chi-Pin Hsu, Chih-Feng Lin, Chih-Chi Yang, Jeng-Ywan Jeng, Chang-Hung Huang, their immediate families and any research foundations with which they are affiliated have not received any financial payments or other benefits from any commercial entity that are related to the subject of this article. Sponsorships: None. Funding This project was supported by cooperative research from National Science and Technology Council (111-2221-E-195 -003 -MY3). Its contents are solely the responsibility of the authors and do not necessarily represent the official views of the donor. Data availability Data availability The datasets generated and/or analyzed during the current study are not publicly available due to the nature of this study, but are available from the corresponding author on reasonable request. Consent for publication Not applicable. References Karataş D, Koç A, Yüksel F, et al. The effect of nasal septal deviation on frontal and maxillary sinus volumes and development of sinusitis. J Craniofac Surg. 2015; 26(5):1508-1512. Natsis K, Karabatakis V, Tsikaras P, et al. Frontal sinus anatomical variations with potential consequences for the orbit. Study on cadavers. Morphologie. 2004; 88(280):35-38. Jang YJ, Park HM, Kim HG. The radiographic incidence of bony defects in the lateral lamella of the cribriform plate. Clin Otolaryngol Allied Sci. 1999; 24(5): 440-442 Lorkiewicz-Muszyńska D, Kociemba W, Rewekant A, et al. Development of the maxillary sinus from birth to age 18. Postnatal growth pattern. Int J Pediatr Otorhinolaryngol. 2015; 79(9):1393-1400. Değermenci M, Ertekin T, Ülger H, et al. The age-related development of maxillary sinus in children. J Craniofac Surg. 2016; 27(1):e38-e44. Vaid S, Vaid N. Normal anatomy and anatomic variants of the paranasal sinuses on computed tomography. Neuroimaging Clin N Am. 2015; 25(4):527-548. Tingelhoff K, Moral AI, Kunkel ME, et al. Comparison between manual and semi-automatic segmentation of nasal cavity and paranasal sinuses from CT images. Conf Proc IEEE Eng Med Biol Soc. 2007;2007:5505-5508. Gabriel OH, Kenneth O, Bright O, Sagbodje DE. Morphology and Anatomical Variations of the Ethmoidal Sinus in Adult Nigerians. International Scholars Journals. 2017; 4 (2):95-100. Ameye, S. A., Amusa, Y. B., Eziyi, J. A. E., & Famurewa, O. C. Assessing the surgical anatomy of the ethmoid sinus in adult Nigerians using computerized tomography scan. Int J Med Med Sci. 2014; 6(12): 239-244. Cankal F, Apaydin N, Acar HI, et al. Evaluation of the anterior and posterior ethmoidal canal by computed tomography. Clin Radiol. 2004; 59(11):1034-1040. Bonfils P, Avan P, Palimi P, Malinvaud D. Evaluation of mucosal surface reduction after ethmoidal surgery in nasal polyposis. J Laryngol Otol. 2007;121(7):1-4. Liu, J., Liu, Q. and Wang, N. Posterior ethmoid cell expansion towards the inferolateral region of the sphenoid sinus: a computed tomography study. Surg Radiol Anat. 2019; 41:1011–1018. Chan MA, Ibrahim F, Kumaran A, et al. Ethnic variation in medial orbital wall anatomy and its implications for decompression surgery. BMC Ophthalmol. 2021; 21:290. ABDALLA, M. A., & HUSSIEN, R. Z. CT Scans Imaging of Human Ethmoid Sinuses and Gross Anatomical Dissection: a Descriptive, Projective, Comparative, and Dimensional Study. Mod Med. 2022; 29(3):213–226. Yang, G., Dai, Y., Dong, C., Niu, Y., Kang, H., & Wang, F. (2023). Two-type classification system for femoral trochlear dysplasia in recurrent patellar instability based on three-dimensional morphology. Knee Surgery, Sports Traumatology, Arthroscopy, 31(5), 1790-1797. Phombut, C., Rooppakhun, S., & Sindhupakorn, B. (2021). Morphometric analysis and three-dimensional computed tomography reconstruction of Thai distal femur. Applied Sciences, 11(3), 1052. Koh, Y. G., Nam, J. H., Chung, H. S., Kim, H. J., Baek, C., & Kang, K. T. (2020). Gender difference exists in sagittal curvature of the distal femoral condyle morphology for osteoarthritic population. Knee Surgery, Sports Traumatology, Arthroscopy, 28, 3740-3746. Zhang, R. Y., Su, X. Y., Zhao, J. X., Li, J. T., Zhang, L. C., & Tang, P. F. (2020). Three-dimensional morphological analysis of the femoral neck torsion angle—an anatomical study. Journal of Orthopaedic Surgery and Research, 15(1), 1-8. Cheng, H., Liu, L., Yu, W., Zhang, H., Luo, D., & Zheng, G. (2015). Comparison of 2.5 D and 3D quantification of femoral head coverage in normal control subjects and patients with hip dysplasia. PLoS One, 10(11), e0143498. Wanzeler, A.M.V., Alves-Júnior, S.M., Ayres, L. et al. Sex estimation using paranasal sinus discriminant analysis: a new approach via cone beam computerized tomography volume analysis. Int J Legal Med. 2019; 133:1977–1984. Zhao, H., Li, Y., Xue, H. et al. Morphological analysis of three-dimensionally reconstructed frontal sinuses from Chinese Han population using computed tomography. Int J Legal Med. 2021;135:1015–1023. Pirinc, B., Fazliogullari, Z., Guler, I. et al. Classification and volumetric study of the sphenoid sinus on MDCT images. Eur Arch Otorhinolaryngol. 2019; 276:2887–2894. Li, Y., Xu, C., Yu, D. et al. Computer-aided superimposition of the frontal sinus via 3D reconstruction for comparative forensic identification. Int J Legal Med. 2021; 135:1993–2001. Hsu, CP., Lee, PY., Wei, HW. et al. Gender differences in femoral trochlea morphology. Knee Surg Sports Traumatol Arthrosc. 2021; 29: 563–572. Yuan Cheng, Wee Kheng Leow and Thiam Chye Lim, Automatic identification of Frankfurt plane and mid-sagittal plane of skull. 2012 IEEE Workshop on the Applications of Computer Vision (WACV), 2012, pp. 233-238. Gendeh, H. S., & Gendeh, B. S. (2022). Paranasal Sinuses Anatomy and Anatomical Variations. Paranasal Sinuses Anatomy and Conditions, 49. Ma, W., Kruth, J.P. NURBS curve and surface fitting for reverse engineering. Int J Adv Manuf Technol. 1998; 14:918–927 . Shi JB, Fu QL, Zhang H, Cheng L, Wang YJ, Zhu DD, Lv W, Liu SX, Li PZ, Ou CQ, Xu G. Epidemiology of chronic rhinosinusitis: results froma cross-sectional survey in seven Chinese cities. Allergy 2015; 70: 533–539. Wang XD, Zheng M, Lou HF, Wang CS, Zhang Y, Bo MY, Ge SQ, Zhang N, Zhang L, Bachert C. An increased prevalence of self-reportedallergic rhinitis in major Chinese cities from 2005 to 2011. Allergy 2016;71: 1170–1180. Schilling, Andrea L., et al. Advances in controlled drug delivery to the sinonasal mucosa. Biomaterials. 2022; 282: 121430. Huang, Zhenxiao, et al. Comparison of bioabsorbable steroid-eluting sinus stents versus nasopore after endoscopic sinus surgery: A multicenter, randomized, controlled, single-blinded clinical trial. Ear Nose Throat J. 2022; 101(4): 260–267. Lim, Dong-Jin, and Do-Yeon Cho. The next generation of sinus stents for chronic rhinosinusitis: A systematic review. Precis futur med. 2023; 6(3): 161-169. Lu, Yung-Chang, et al. Biomechanical characteristics of self-expanding sinus stents during crimping and deployment_A comparison between different biomaterials. J Mech Behav Biomed Mater. 2023; 138:105669. Tables Table 1 is available in the Supplementary Files section. Additional Declarations No competing interests reported. Supplementary Files Table.pdf Cite Share Download PDF Status: Under Review Version 1 posted Editorial decision: Revision requested 14 May, 2024 Reviews received at journal 08 May, 2024 Reviews received at journal 28 Apr, 2024 Reviewers agreed at journal 28 Apr, 2024 Reviewers agreed at journal 24 Apr, 2024 Reviewers invited by journal 24 Apr, 2024 Editor invited by journal 24 Apr, 2024 Editor assigned by journal 10 Apr, 2024 Submission checks completed at journal 10 Apr, 2024 First submitted to journal 01 Apr, 2024 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-4199542","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":289535843,"identity":"eeefb4d5-b098-4f7c-a242-1b505469331c","order_by":0,"name":"Chi-Pin Hsu","email":"","orcid":"","institution":"National Taiwan University of Science and Technology","correspondingAuthor":false,"prefix":"","firstName":"Chi-Pin","middleName":"","lastName":"Hsu","suffix":""},{"id":289535845,"identity":"256f8b2e-fda5-4013-b8df-fe99f8e9cf59","order_by":1,"name":"Chih-Feng Lin","email":"","orcid":"","institution":"National Taiwan University 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09:08:05","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-4199542/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-4199542/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":54928499,"identity":"6f41bd5f-e8ff-4cd7-8521-f3b4741b9c5a","added_by":"auto","created_at":"2024-04-18 17:39:01","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":1894579,"visible":true,"origin":"","legend":"\u003cp\u003eMethodology of the 3D model reconstruction and measurement process\u003c/p\u003e","description":"","filename":"FigureBingo202404091.png","url":"https://assets-eu.researchsquare.com/files/rs-4199542/v1/52e5ae0030455c3309a70a29.png"},{"id":54929255,"identity":"14090484-b133-4e66-ad01-5b34cb100e96","added_by":"auto","created_at":"2024-04-18 17:47:01","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":1848025,"visible":true,"origin":"","legend":"\u003cp\u003eCoordinate definition and correction of image orientation: (A) sagittal view, (B) axial view and (C) coronal view\u003c/p\u003e","description":"","filename":"FigureBingo202404092.png","url":"https://assets-eu.researchsquare.com/files/rs-4199542/v1/4a9d7f437841905f5fb560b3.png"},{"id":54928496,"identity":"cc076646-3454-4245-a713-db41eb768a4c","added_by":"auto","created_at":"2024-04-18 17:39:01","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":64516,"visible":true,"origin":"","legend":"\u003cp\u003eAverage height and width of the ES for a male and a female in each section: (A) width and (B) height\u003c/p\u003e","description":"","filename":"FigureBingo202404093.png","url":"https://assets-eu.researchsquare.com/files/rs-4199542/v1/b65a43bf661813a757b5d57c.png"},{"id":54928495,"identity":"4f500d8b-b3a1-4096-96ed-5e6af6296823","added_by":"auto","created_at":"2024-04-18 17:39:01","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":117499,"visible":true,"origin":"","legend":"\u003cp\u003eAverage aspect ratio of the ES in different sections: (A) for gender difference and (B) for symmetry difference\u003c/p\u003e","description":"","filename":"FigureBingo202404094.png","url":"https://assets-eu.researchsquare.com/files/rs-4199542/v1/84567c7252918cf908cc007a.png"},{"id":54929254,"identity":"0e6b928f-fa40-4160-b259-f32690dfa9e6","added_by":"auto","created_at":"2024-04-18 17:47:01","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":1319624,"visible":true,"origin":"","legend":"\u003cp\u003eDiagram showing the shape of the ES in the anterior and posterior sections (A) the AR of the ES in the anterior and posterior sections (B)reconstructing ES model according section curve.\u003c/p\u003e","description":"","filename":"FigureBingo202404095.png","url":"https://assets-eu.researchsquare.com/files/rs-4199542/v1/dfc410ddcebff23b5e0172ca.png"},{"id":54928497,"identity":"c0180d16-0e16-40e0-a634-b97415b1fe80","added_by":"auto","created_at":"2024-04-18 17:39:01","extension":"png","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":56675,"visible":true,"origin":"","legend":"\u003cp\u003eThe average orientation difference between the original CT and the corrected model\u003c/p\u003e","description":"","filename":"FigureBingo202404096.png","url":"https://assets-eu.researchsquare.com/files/rs-4199542/v1/ffb851a900b51002454c8634.png"},{"id":54929510,"identity":"febe1408-e6f7-48db-a3e3-afd27e46d24e","added_by":"auto","created_at":"2024-04-18 17:55:02","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2333816,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4199542/v1/fcd1524c-21d1-474c-b9e3-269ac0967c84.pdf"},{"id":54928498,"identity":"526dc3ff-a75e-431e-9aa9-691cf7936c6c","added_by":"auto","created_at":"2024-04-18 17:39:01","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"supplement","size":94005,"visible":true,"origin":"","legend":"","description":"","filename":"Table.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4199542/v1/e7aacb377e380186622e12e9.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Gender Differences in Ethmoid Sinus Morphology","fulltext":[{"header":"Introduction","content":"\u003cp\u003eThe nasal sinuses are an anatomically complex, interconnected system with air pockets that are connected to the nasal passages by cavities. The morphology of the nasal sinus varies significantly and is influenced by genetic diseases, infectious diseases, or environmental conditions [1-5]. Modern medical imaging technology allows the detection of sinus lesions, which improves the accuracy of measurement and allows appropriate planning for intranasal surgery [6,7].\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe ES is a common site for functional endoscopic sinus surgery (FESS) [8]. Its size and appearance are important indicators during FESS surgery. Many morphometrical studies used 2D plane image technology to depict the 3D ES anatomy [8-14]. Those results differed between studies and the average length of the ES ranged from 37.2\u0026plusmn;4.6 to 41.4\u0026plusmn;4.0 mm, and the width ranged from 11.6\u0026plusmn;2.2 to 16.7\u0026plusmn;3.8 mm [8-14]. The errors may raise owing to the tilting of the head during scanning or slice non-orthogonal with sinus if using 2D measures (Fig 1A). Moreover, prior studies analyzing the data in human skeleton system [15-19] have confirmed that the measured data from 3D reconstruction measurement results are more consistent and accurate than that from 2D measures.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eSome morphological studies have reported racial and gender differences in sinus [8,14-16]. One recent study showed that Chinese ES was about 16% wider than examples from another study [13]. The study reported that a Chinese male ES was around 13% higher than that of a female [13], but the opposite is true for Africans [8]. These studies showed that the anatomy of the sinus was affected by factors such as race, gender or the measurement method. Most of the data for previous studies was collected using 2D CT images. Although other studies used 3D measure strategies but they only calculated the volume [20,21] or just used to classify the shape classifications [22,23]. Three-dimensional data for the ES structure has yet to be collected.\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;This study aimed to measure the 3D structure of the ES by using a CT image reconstruction model. This model reconstruction and measurement method has been approved in the research team\u0026rsquo;s prior study when measuring the lower extremity of the human body [24]. The outline at each cutting-plane section of the ES was measured to determine the entire structure of the ES. The ES geometry for male and female subjects was also compared to determine any difference between genders in Asian populations. It is hypothesized that the ES of male subjects is significantly larger than that of females.\u003c/p\u003e"},{"header":"Materials and Methods","content":"\u003cp\u003eThis study included subjects from patients with nasolacrimal duct stenosis for dacryocystorhinostomy, pituitary or skull base tumors who underwent surgery, and those who complained of olfactory dysfunction but demonstrated normal sinonasal findings on their computed tomography scans. Patients with previous sinonasal surgery for anatomical or inflammatory conditions, head and neck cancer received radiotherapy, trauma, orthognathic surgery, or congenital sinonasal disorders were excluded from the enrollment.\u0026nbsp;A total of 36 subjects (21 males and 15 females) were included in the study\u0026nbsp;which was\u0026nbsp;approved by\u0026nbsp;the Institutional Review Board (201912187RINA). The average age of the subjects is 55.4 years (21~99): a mean of 52.0 years old for males and 59.2 for females. All subjects had intact sinuses on both sides so a total of 72 sinus data points (42 male and 30 female data) were analyzed.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe measurement process for this study is shown in Fig. 1.\u0026nbsp;CT scans were performed using a multi-slice CT machine (Sensation 16 SLICE, SIEMENS, Memphis, USA) with a 1mm slice thickness (120 Kv, 20 mA). Image segmentation and reconstruction used OOOPDS (Main Orthopedic Biotechnology Co., Ltd., Taichung City, Taiwan).\u0026nbsp;The image was first correctly oriented using the criteria for the Frankfurt plane [25]. The ethmoid sinus (ES) level and the coordinates were then defined (Fig.1A).\u0026nbsp;The sinus cavity region is used to define the appearance of the sinus. The sinus was then segmented into the sphenoid sinus (SS), the frontal sinus (FS), the maxillary sinus (MS), the ethmoid sinus (ES) and the nasal cavity (Fig.1B). The sinus cavity is reconstructed as a 3D model, and a boundary surface is defined by the standard anatomy of the ES (Fig.1C-E). This study focuses on the standard anatomical narrative of the ES area [26]. The ES model then removed the area outside the boundary surface and constructs cutting plane increments of 10% in the anterior-posterior (AP) direction for the remaining ES models (Fig.1F). The cutting plane and the overlapping position of the ES model is the section contour of the ES. The total length of the ES and the width and height of each section were measured and the differences between genders were further determined (Fig.1F).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eDefinition of the coordinate system and the correct orientation of the images\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eDifferent image orientations produce errors in measurement so the coordinate system is defined initially. The coordinate definition uses the Frankfurt plane [25]. The cranial base in the sagittal view is used as the horizontal basis to correct the Y-axis rotation of the model (Fig.2A). The Z-axis rotation is corrected using the nasal septum in the axial view as the vertical basis (Fig.2B). The X-axis rotation of the model is then corrected using the cranial base and the nasal septum in the coronal view as the vertical and horizontal basis (Fig.2C).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eDefining and constructing ES model and boundaries\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe sphenoid, frontal, maxillary, ES and nasal cavities are segmented and reconstructed for this study (Fig. 1B and 1C). The correctness of the image segmentation was confirmed by two ENT surgeons who are co-authors of this study (Lin CF and\u0026nbsp;Yang CC). The boundaries of the ES were defined based on standard anatomical descriptions (Fig. 1D) [26]. The upper boundary is defined as the cranial base, the outer boundary is periorbital and the inner boundary is middle turbinate. The boundary of each section is reconstructed as a boundary surface of the 3D model (Fig.1E).\u0026nbsp;The irrelevant area beyond the boundary surface is removed, so the remaining area of ES is the target for subsequent measurements (Fig. 1F). All cavities of the sinuses are reconstructed as 3D models and the correctness of the division was verified by two coauthors to minimize the error in boundary definition.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMeasurement of the ethmoid sinus\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eReverse engineering software RevCAD V1.50 (PouYuen Tech Corp., Taoyuan, Taiwan) was used to create cutting planes (Fig.1F). In order to analyze the complex anatomical appearance of ES objectively, the total length of the ES is used as a benchmark and the starting plane is through the frontmost point of the ES and perpendicular to the Y axis. Cutting planes are established at every 10% increment of the total length. The vertical distance between the 0% and 100% cutting planes is defined as the ES length (L) (Fig.1F).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe intersection of the cutting planes and ES are defined as cutting points. The closed curve is calculated using a B-spline curve fitting algorithm with the cutting points (Fig. 1G)[27]. The distance from maximum Z\u003cem\u003e\u003csub\u003ei\u003c/sub\u003e\u003c/em\u003e to minimum Z\u003cem\u003e\u003csub\u003ei\u003c/sub\u003e\u003c/em\u003e for the closed curve is the height (H\u003cem\u003e\u003csub\u003ei\u003c/sub\u003e\u003c/em\u003e) of this ES section (Fig.1H), where \u003cem\u003ei\u003c/em\u003e=0%, 10%, 20%,\u0026hellip;, 100%. The distance from maximum Y\u003cem\u003e\u003csub\u003ei\u003c/sub\u003e\u0026nbsp;\u003c/em\u003eto minimum Y\u003cem\u003e\u003csub\u003ei\u003c/sub\u003e\u0026nbsp;\u003c/em\u003efor the closed curve is the width (W\u003cem\u003e\u003csub\u003ei\u003c/sub\u003e\u003c/em\u003e) of the ES section (Fig.1H). For this study, the aspect ratio (AR) of width to height for each ES section is defined as AR\u003cem\u003e\u003csub\u003ei\u003c/sub\u003e\u0026nbsp;\u003c/em\u003e= W\u003cem\u003e\u003csub\u003ei\u003c/sub\u003e/\u003c/em\u003eH\u003cem\u003e\u003csub\u003ei\u003c/sub\u003e\u003c/em\u003e, AR\u003cem\u003e\u003csub\u003ei\u003c/sub\u003e\u0026nbsp;\u003c/em\u003eand is used to determine the change in shape for each section of the chamber, which clearly defines the anatomy.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eStatistical analysis\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eTo ensure that the data is normally distributed, the Kolmogorov-Smirnov test was used and proven for \u003cem\u003ep\u003c/em\u003e \u0026gt; 0.05 in parametric statistics. \u0026nbsp;G-power 3.1 was used for a post hoc power analysis of gender differences, with \u0026alpha; = 0.05, and the calculated statistical power is 97%. Statistical data is analyzed using SPSS (version 20, SPSS Inc., Chicago, IL, USA) and independent \u003cem\u003et\u003c/em\u003e-tests are used to determine the significance of gender differences. A value of \u003cem\u003ep\u003c/em\u003e \u0026lt; 0.05 indicates statistical significance.\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003eThe average ES length for the male group is 40.1\u0026plusmn;5.0 mm and for the female group is 41.3\u0026plusmn;5.0 mm. There is no significant difference between genders (\u003cem\u003ep\u003c/em\u003e=0.140) (Table 1). Figure 4A shows the average width of each section. The maximum width of the male ES is W\u003csub\u003e60\u003c/sub\u003e=12.0 \u0026plusmn; 2.1 mm and the maximum width of the female ES is W\u003csub\u003e80\u003c/sub\u003e=10.0 \u0026plusmn; 2.1 mm. The male ES is significantly wider than the female ES. Except for W\u003csub\u003e10\u003c/sub\u003e (\u003cem\u003ep\u003c/em\u003e=0.064), there is a statistically significant difference in most of the sections (\u003cem\u003ep\u0026lt;\u003c/em\u003e0.05). Figure 4B shows the average height of each section. The male and female ES has a maximum height at H\u003csub\u003e40\u003c/sub\u003e (18.4\u0026plusmn;3.5 mm and 18.2\u0026plusmn;3.4 mm). The maximum height for the male group is slightly greater than that for the female group for all ES heights, but the only significant difference is at H\u003csub\u003e60\u003c/sub\u003e (\u003cem\u003ep\u003c/em\u003e=0.045) and H\u003csub\u003e80\u003c/sub\u003e (\u003cem\u003ep\u003c/em\u003e=0.048).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe largest and smallest aspect ratio (AR) values for the male group are AR\u003cem\u003e\u003csub\u003e90\u003c/sub\u003e\u003c/em\u003e=0.9\u0026plusmn;0.5 and AR\u003cem\u003e\u003csub\u003e20\u003c/sub\u003e\u003c/em\u003e=0.6\u0026plusmn;0.2, respectively (Fig. 4A), and for the female group, these values are AR\u003csub\u003e90\u003c/sub\u003e=0.8\u0026plusmn;0.2 and AR\u003csub\u003e30\u003c/sub\u003e=0.5\u0026plusmn;0.1, respectively. The AR values for the male group are larger than those for the female group. There is a significant difference from AR\u003cem\u003e\u003csub\u003e40\u003c/sub\u003e\u003c/em\u003e to AR\u003cem\u003e\u003csub\u003e70\u003c/sub\u003e\u003c/em\u003e but the AR value for the anterior section (AR\u003cem\u003e\u003csub\u003e10\u003c/sub\u003e\u003c/em\u003e- AR\u003cem\u003e\u003csub\u003e50\u003c/sub\u003e\u003c/em\u003e) for the male group is 19.4% smaller on average than that for the posterior section (AR\u003cem\u003e\u003csub\u003e50\u003c/sub\u003e\u003c/em\u003e- AR\u003cem\u003e\u003csub\u003e90\u003c/sub\u003e\u003c/em\u003e). The anterior section for the female group is 18.3% smaller on average than the AR value for the posterior section. There are significant differences between AR\u003csub\u003e10\u003c/sub\u003e vs. AR\u003csub\u003e90\u003c/sub\u003e, AR\u003csub\u003e20\u003c/sub\u003e vs. AR\u003csub\u003e80\u003c/sub\u003e, AR\u003csub\u003e30\u003c/sub\u003e vs. AR\u003csub\u003e70\u003c/sub\u003e, and AR\u003csub\u003e40\u003c/sub\u003e vs. AR\u003csub\u003e60\u003c/sub\u003e. The AR for the left ES is slightly greater than the value for the right side (Fig. 4B) but there is no significant difference (\u003cem\u003ep\u003c/em\u003e=0.26).\u003c/p\u003e\n\u003cp\u003eThe AR of the cross-section is about 0.6for the anterior sections, so the cross-section of the ES in the anterior sections is close to an elliptical cylinder (Fig. 5A). However, the AR valuesfor the cross-section in the posterior part are about 0.7-0.9, so the cross-sections in the posterior parts is almost circular.\u0026nbsp;\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThe ES is the most anatomically complex part of the nasal sinuses. It is created by the ethmoid bone, forming multiple pyramidal air cells. For this study, the 3D ES model is reconstructed to measure the detail of the ES section. \u0026nbsp;This study allows a more accurate description of the anatomy of the ES than the 2D measurements that are used by other studies [8-14].\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eMost studies use 2D or planar images to measure the length of ES [8-14]. Those studies use one image that is the uppermost edge of the optical canal in several axial-view images and measure the length of ES using this image. However, the orientation of the 2D image is affected by the subject\u0026rsquo;s posture during the CT scan (Fig. 2). In this study, subjects used a head fixation device when taking CT scans. However, the average orientation difference between the original CT and the corrected model is 9.1\u0026deg;\u0026plusmn;10.6, 1.8\u0026deg;\u0026plusmn;2.4 and 2.1\u0026deg;\u0026plusmn;2.7 in the sagittal, axial and coronal plane (Fig. 6). Especially in the sagittal plane, the orientation difference is 3.3 times and 4.2 times than the axial and coronal plane. So, the CT images are not orthogonal to the landmarks of the ES structure. The 2D or planar measurement method produces more errors than 3D reconstruction measurement methods [15-19,21].\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe orientation of the 3D model is corrected for this study using the standard for the Frankfurt plane, so all models are set using the same coordinate. One study [13] reported the maximum respective ES length for male and female groups as 37.6\u0026plusmn;3.4 mm and 37.0\u0026plusmn;4.13 mm using 2D measurement. The measurements of the ES using the 3D method of this study are much longer than those that are obtained using 2D measurement (Table 1).\u003c/p\u003e\n\u003cp\u003eThe height of ES is an important measure; however, more data is needed for 2D measurement studies [8-14]. This study used a complete sinus model so the anatomical location and identification of ES regions is much clearer. The height of each section of the ES and the width of the ES were measured continuously at every 10% interval of the ES length (Fig. 1H and Fig. 4). The results showed that the average height of the ES for a Chinese male was 13.7\u0026plusmn;6.6 mm and for a Chinese female is 13.0\u0026plusmn;6.2 mm. No significant difference in the height of the ES was found for male and female groups (\u003cem\u003ep\u003c/em\u003e\u0026gt;0.05) but there is a statistically significant difference in width. The average width of the ES for a Chinese male was 9.1\u0026plusmn;4.1mm and for a Chinese female was 7.8\u0026plusmn;3.4 mm. The male ES is about 20.0% larger than that of the female.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe difference between the measurement results for this study and those of other studies, in terms of length, width and height are about -47%‒3%, -14%‒78% and 12%‒64%, respectively (Table 1). The results showed that there is a significant difference between the results of this study and the measurements for other studies, possibly because of the difference between the 3D and 2D measurement methods, the measurement location or ethnic differences.\u003c/p\u003e\n\u003cp\u003eThe shape of an ES section is defined using the aspect ratio of the width to the height of the ES. If AR=1, the shape is a circle and ifAR\u0026lt;1, it is closer to an ellipse. The results of this study showed that the average shape of ES is closer to an ellipse, especially for the anterior ES (AR\u003csub\u003e10\u003c/sub\u003e-AR\u003csub\u003e50\u003c/sub\u003e), for which the AR value is about 0.60, and the posterior ES (AR\u003csub\u003e50\u003c/sub\u003e-AR\u003csub\u003e90\u003c/sub\u003e), for which the AR value is about 0.74 (Fig.5A). The aspect ratio for the end of the ES (AR\u003csub\u003e80\u003c/sub\u003e-AR\u003csub\u003e90\u003c/sub\u003e) is about 0.9, so posterior ES is approximately like a circle in the final section. As for the AR value in male ES is significantly greater than that for a female, particularly in the range of AR\u003csub\u003e40\u003c/sub\u003e- AR\u003csub\u003e70\u003c/sub\u003e.\u003c/p\u003e\n\u003cp\u003eA large number of Asian people suffer from chronic sinusitis [28,29] and may require a stent to prevent restenosis after ES surgery [30-32]. Determining the 3D structure of an ES cavity allows more accurate planning for nasal surgery. The current ES stent has a circular section after it is deployed [30], but the anterior part should be elliptical and the posterior part should be almost circular. So, it does not fit the cavity shape. Our previous biomechanics study [33] analyzed the contact behavior of a nasal stent that was deployed to the ES cavity and showed that there was a significant rise of contact stress on the inside of the ES and a part of the stent material has caused permanent plastic deformation possibly due to mismatch between the stent and nasal cavity. If the shape of the implant deviates too much from the shape of the ES, excessive stress can occur and the ES can become loose [33]. The design of a commercial stent should ensure optimal stent-ES contact in the ES cavity. The section curve and the aspect ratio of the ES can provide helpful information for the improvement of the nasal device (Fig. 5B).\u003c/p\u003e\n\u003cp\u003eThis study has some limitations that should be mentioned here. \u0026nbsp; First, the subject number is not big enough. The current study primarily developed a new measurement method to obtain 3D results in this stage and we will keep enrolling more data in the near future. \u0026nbsp;Second, in order to obtain the most typical measurement data, this study only included normal anatomy cases. \u0026nbsp;However, the morphology of ES may differ from the typical one after FESS. Third, the standard anatomy of the ES defined the upper (cranial base), outer (periorbital), and inner boundary (middle turbinate), but not inferior boundary [26]. \u0026nbsp;Therefore, this study defined the inferior boundary by the lowest point of section curve (Fig.1 G). Finally, there are multiple ways to demarcate and measure the morphology but it is difficult to define the boundaries of these complex air sacs. In addition to the limitations mentioned above, the current study has put new information to know the continuous change of the ES.\u0026nbsp;\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eThis three-dimensional morphometrical measurement showed that the sinus cavity constantly changes from anterior to posterior. The male ES is significantly wider than the female. \u0026nbsp;The aspect ratio result indicates that the anterior ES is closer to an elliptical shape, but the shape is similar to a circle in the posterior section instead. The aspect ratio of the middle section of a male ES is significantly greater than that of a female.\u003c/p\u003e\n\u003cp\u003e\u003cbr\u003e\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAuthors\u0026rsquo; Contributions:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eChi-Pin Hsu: Conceived the study design, helped to draft the manuscript and supervised the study,\u0026nbsp;analyzed and interpreted the data.\u003c/p\u003e\n\u003cp\u003eChih-Feng Lin:\u0026nbsp;Acquired the data,\u0026nbsp;analyzed and interpreted the data, drafted the manuscript\u003c/p\u003e\n\u003cp\u003eChih-Chi Yang:\u0026nbsp;Acquired,\u0026nbsp;analyzed and interpreted\u0026nbsp;the data\u003c/p\u003e\n\u003cp\u003eJeng-Ywan Jeng: Helped to draft the manuscript and supervised the study\u003c/p\u003e\n\u003cp\u003eChang-Hung Huang: Conceived the study design,\u0026nbsp;helped to\u0026nbsp;interpreted the data, draft the manuscript and supervised the study\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics approval\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study is approved by the Institutional Review Board of National Taiwan University Hospital (IRB number: 201912187RINA). Because of the retrospective nature of the study, the requirement for informed consent was waived. The study was performed in accordance with the Declaration of Helsinki. All methods were carried out in accordance with relevant guidelines and regulations.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgments\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe are also grateful to the National Science and Technology Council (111-2221-E-195 -003 -MY3) for providing financial support for our research. Their generous funding allowed us to conduct our study and complete our work.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eDisclosures\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eCompeting interests:\u0026nbsp;The authors\u0026nbsp;Chi-Pin Hsu, Chih-Feng Lin, Chih-Chi Yang, Jeng-Ywan Jeng, Chang-Hung Huang, their immediate families and any research foundations with which they are affiliated have not received any financial payments or other benefits from any commercial entity that are related to the subject of this article.\u003c/p\u003e\n\u003cp\u003eSponsorships: None.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis project was supported by cooperative research from National Science and Technology Council (111-2221-E-195 -003 -MY3). Its contents are solely the responsibility of the authors and do not necessarily represent the official views of the donor.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData availability\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eData availability The datasets generated and/or analyzed during the current study are not publicly available due to the nature of this study, but are available from the corresponding author on reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n \u003cli\u003eKarataş D, Ko\u0026ccedil; A, Y\u0026uuml;ksel F, et al. The effect of nasal septal deviation on frontal and maxillary sinus volumes and development of sinusitis. J Craniofac Surg. 2015; 26(5):1508-1512.\u003c/li\u003e\n \u003cli\u003eNatsis K, Karabatakis V, Tsikaras P, et al. Frontal sinus anatomical variations with potential consequences for the orbit. Study on cadavers. Morphologie. 2004; 88(280):35-38.\u003c/li\u003e\n \u003cli\u003eJang YJ, Park HM, Kim HG. The radiographic incidence of bony defects in the lateral lamella of the cribriform plate. Clin Otolaryngol Allied Sci. 1999; 24(5):\u0026nbsp;440-442\u003c/li\u003e\n \u003cli\u003eLorkiewicz-Muszyńska D, Kociemba W, Rewekant A, et al. Development of the maxillary sinus from birth to age 18. Postnatal growth pattern. Int J Pediatr Otorhinolaryngol. 2015; 79(9):1393-1400.\u003c/li\u003e\n \u003cli\u003eDeğermenci M, Ertekin T, \u0026Uuml;lger H, et al. The age-related development of maxillary sinus in children. J Craniofac Surg. 2016; 27(1):e38-e44.\u003c/li\u003e\n \u003cli\u003eVaid S, Vaid N. Normal anatomy and anatomic variants of the paranasal sinuses on computed tomography. Neuroimaging Clin N Am. 2015; 25(4):527-548.\u003c/li\u003e\n \u003cli\u003eTingelhoff K, Moral AI, Kunkel ME, et al. Comparison between manual and semi-automatic segmentation of nasal cavity and paranasal sinuses from CT images. Conf Proc IEEE Eng Med Biol Soc. 2007;2007:5505-5508.\u003c/li\u003e\n \u003cli\u003eGabriel OH, Kenneth O, Bright O, Sagbodje DE. Morphology and Anatomical Variations of the Ethmoidal Sinus in Adult Nigerians. International Scholars Journals. 2017; 4 (2):95-100.\u003c/li\u003e\n \u003cli\u003eAmeye, S. A., Amusa, Y. B., Eziyi, J. A. E., \u0026amp; Famurewa, O. C. Assessing the surgical anatomy of the ethmoid sinus in adult Nigerians using computerized tomography scan. Int J Med Med Sci. 2014; 6(12): 239-244.\u003c/li\u003e\n \u003cli\u003eCankal F, Apaydin N, Acar HI, et al. Evaluation of the anterior and posterior ethmoidal canal by computed tomography. Clin Radiol. 2004; 59(11):1034-1040.\u003c/li\u003e\n \u003cli\u003eBonfils P, Avan P, Palimi P, Malinvaud D. Evaluation of mucosal surface reduction after ethmoidal surgery in nasal polyposis.\u0026nbsp;J Laryngol Otol. 2007;121(7):1-4.\u003c/li\u003e\n \u003cli\u003eLiu, J., Liu, Q. and Wang, N. Posterior ethmoid cell expansion towards the inferolateral region of the sphenoid sinus: a computed tomography study. Surg Radiol Anat. 2019; 41:1011\u0026ndash;1018.\u003c/li\u003e\n \u003cli\u003eChan MA, Ibrahim F, Kumaran A, et al. Ethnic variation in medial orbital wall anatomy and its implications for decompression surgery. BMC Ophthalmol. 2021; 21:290.\u003c/li\u003e\n \u003cli\u003eABDALLA, M. A., \u0026amp; HUSSIEN, R. Z. CT Scans Imaging of Human Ethmoid Sinuses and Gross Anatomical Dissection: a Descriptive, Projective, Comparative, and Dimensional Study. Mod Med. 2022; 29(3):213\u0026ndash;226.\u003c/li\u003e\n \u003cli\u003eYang, G., Dai, Y., Dong, C., Niu, Y., Kang, H., \u0026amp; Wang, F. (2023). Two-type classification system for femoral trochlear dysplasia in recurrent patellar instability based on three-dimensional morphology. Knee Surgery, Sports Traumatology, Arthroscopy, 31(5), 1790-1797.\u003c/li\u003e\n \u003cli\u003ePhombut, C., Rooppakhun, S., \u0026amp; Sindhupakorn, B. (2021). Morphometric analysis and three-dimensional computed tomography reconstruction of Thai distal femur. Applied Sciences, 11(3), 1052.\u003c/li\u003e\n \u003cli\u003eKoh, Y. G., Nam, J. H., Chung, H. S., Kim, H. J., Baek, C., \u0026amp; Kang, K. T. (2020). Gender difference exists in sagittal curvature of the distal femoral condyle morphology for osteoarthritic population. Knee Surgery, Sports Traumatology, Arthroscopy, 28, 3740-3746.\u003c/li\u003e\n \u003cli\u003eZhang, R. Y., Su, X. Y., Zhao, J. X., Li, J. T., Zhang, L. C., \u0026amp; Tang, P. F. (2020). Three-dimensional morphological analysis of the femoral neck torsion angle\u0026mdash;an anatomical study. Journal of Orthopaedic Surgery and Research, 15(1), 1-8.\u003c/li\u003e\n \u003cli\u003eCheng, H., Liu, L., Yu, W., Zhang, H., Luo, D., \u0026amp; Zheng, G. (2015). Comparison of 2.5 D and 3D quantification of femoral head coverage in normal control subjects and patients with hip dysplasia. PLoS One, 10(11), e0143498.\u003c/li\u003e\n \u003cli\u003eWanzeler, A.M.V., Alves-J\u0026uacute;nior, S.M., Ayres, L. et al. Sex estimation using paranasal sinus discriminant analysis: a new approach via cone beam computerized tomography volume analysis. Int J Legal Med. 2019; 133:1977\u0026ndash;1984.\u003c/li\u003e\n \u003cli\u003eZhao, H., Li, Y., Xue, H. et al. Morphological analysis of three-dimensionally reconstructed frontal sinuses from Chinese Han population using computed tomography. Int J Legal Med. 2021;135:1015\u0026ndash;1023.\u003c/li\u003e\n \u003cli\u003ePirinc, B., Fazliogullari, Z., Guler, I. et al. Classification and volumetric study of the sphenoid sinus on MDCT images. Eur Arch Otorhinolaryngol. 2019; 276:2887\u0026ndash;2894.\u003c/li\u003e\n \u003cli\u003eLi, Y., Xu, C., Yu, D. et al. Computer-aided superimposition of the frontal sinus via 3D reconstruction for comparative forensic identification. Int J Legal Med. 2021; 135:1993\u0026ndash;2001.\u003c/li\u003e\n \u003cli\u003eHsu, CP., Lee, PY., Wei, HW. et al. Gender differences in femoral trochlea morphology. Knee Surg Sports Traumatol Arthrosc. 2021; 29: 563\u0026ndash;572.\u003c/li\u003e\n \u003cli\u003eYuan Cheng, Wee Kheng Leow and Thiam Chye Lim, Automatic identification of Frankfurt plane and mid-sagittal plane of skull. 2012 IEEE Workshop on the Applications of Computer Vision (WACV), 2012, pp. 233-238.\u003c/li\u003e\n \u003cli\u003eGendeh, H. S., \u0026amp; Gendeh, B. S. (2022). Paranasal Sinuses Anatomy and Anatomical Variations. Paranasal Sinuses Anatomy and Conditions, 49.\u003c/li\u003e\n \u003cli\u003eMa, W., Kruth, J.P. NURBS curve and surface fitting for reverse engineering. Int J Adv Manuf Technol. 1998; 14:918\u0026ndash;927 .\u003c/li\u003e\n \u003cli\u003eShi JB, Fu QL, Zhang H, Cheng L, Wang YJ, Zhu DD, Lv W, Liu SX, Li PZ, Ou CQ, Xu G. Epidemiology of chronic rhinosinusitis: results froma cross-sectional survey in seven Chinese cities. Allergy 2015; 70: 533\u0026ndash;539.\u003c/li\u003e\n \u003cli\u003eWang XD, Zheng M, Lou HF, Wang CS, Zhang Y, Bo MY, Ge SQ, Zhang N, Zhang L, Bachert C. An increased prevalence of self-reportedallergic rhinitis in major Chinese cities from 2005 to 2011. Allergy 2016;71: 1170\u0026ndash;1180.\u003c/li\u003e\n \u003cli\u003eSchilling, Andrea L., et al. Advances in controlled drug delivery to the sinonasal mucosa. Biomaterials. 2022; 282: 121430.\u003c/li\u003e\n \u003cli\u003eHuang, Zhenxiao, et al. Comparison of bioabsorbable steroid-eluting sinus stents versus nasopore after endoscopic sinus surgery: A multicenter, randomized, controlled, single-blinded clinical trial.\u0026nbsp;Ear Nose Throat J. 2022; 101(4): 260\u0026ndash;267.\u003c/li\u003e\n \u003cli\u003eLim, Dong-Jin, and Do-Yeon Cho. The next generation of sinus stents for chronic rhinosinusitis: A systematic review. Precis futur med.\u0026nbsp;2023; 6(3): 161-169.\u003c/li\u003e\n \u003cli\u003eLu, Yung-Chang, et al. Biomechanical characteristics of self-expanding sinus stents during crimping and deployment_A comparison between different biomaterials. J Mech Behav Biomed Mater. 2023; 138:105669.\u003c/li\u003e\n\u003c/ol\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e"},{"header":"Tables","content":"\u003cp\u003eTable 1 is available in the Supplementary Files section.\u003c/p\u003e\n"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"bmc-medical-imaging","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bmim","sideBox":"Learn more about [BMC Medical Imaging](http://bmcmedimaging.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/bmim/default.aspx","title":"BMC Medical Imaging","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Ethmoid sinus, Morphometrical analysis, 3D reconstruction, Computed Tomography, Gender difference","lastPublishedDoi":"10.21203/rs.3.rs-4199542/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-4199542/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground \u003c/strong\u003eThe ethmoid sinus (ES) is a three-dimensional (3D) complex structure, a clear understanding of the ES anatomy is helpful to plan intranasal surgery. However, most prior studies use 2D measurements, which may not accurately depict the 3D structure. The current study measured the gender differences in ES morphology based on 3D reconstruction of computed tomography (CT) images.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMethods \u003c/strong\u003eThe 3D models were reconstructed using CT images. Twenty-one males and 15 females were enrolled in the study. The ES dimensions, including width, height and aspect ratio (AR) of each cutting-plane section, were measured at 10% increments along with the anteroposterior axis of the ES. The gender differences in the above parameters were further evaluated by an independent \u003cem\u003et\u003c/em\u003e-test.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults \u003c/strong\u003eThe width of the ES for males is 12.0±2.1mm, which was significantly greater than that in females (10.0±2.1 mm). The average height for males is 18.4±3.5mm, and 18.2±3.4mm for females. The AR of female (male) is around 0.56 (0.63) for the anterior ES and 0.66 (0.75) for the posterior. There are significant differences between genders in the parameters of width and AR (\u003cem\u003ep\u003c/em\u003e\u0026lt;0.05)\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusion \u003c/strong\u003eThis study found that the AR greatly varies along the length of ES, indicating that the cross-section of the ES in the anterior is closer to an elliptical shape and turns closer to a circular shape near its posterior. There is a significant difference between genders in width and AR. The results would be helpful to know the complex anatomic details of the ethmoid sinus.\u003c/p\u003e","manuscriptTitle":"Gender Differences in Ethmoid Sinus Morphology","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-04-18 17:38:56","doi":"10.21203/rs.3.rs-4199542/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2024-05-14T05:05:06+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2024-05-08T15:09:22+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2024-04-28T12:10:50+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"4ac47632-0408-49fc-8f64-50d4978969fc","date":"2024-04-28T08:15:47+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"c230841b-9c44-4baf-9ffb-35d4eee73ca7_SNPRID","date":"2024-04-24T10:06:53+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2024-04-24T07:38:56+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2024-04-24T05:37:22+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2024-04-10T05:54:31+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2024-04-10T05:53:46+00:00","index":"","fulltext":""},{"type":"submitted","content":"BMC Medical Imaging","date":"2024-04-01T09:06:50+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-medical-imaging","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bmim","sideBox":"Learn more about [BMC Medical Imaging](http://bmcmedimaging.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/bmim/default.aspx","title":"BMC Medical Imaging","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"aa9aa910-9a70-499f-92c8-b55a7b87d241","owner":[],"postedDate":"April 18th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2024-06-04T06:41:40+00:00","versionOfRecord":[],"versionCreatedAt":"2024-04-18 17:38:56","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-4199542","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-4199542","identity":"rs-4199542","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}